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Sample records for power-plutonium production reactor richland

  1. Management of Hanford Site non-defense production reactor spent nuclear fuel, Hanford Site, Richland, Washington

    SciTech Connect

    1997-03-01

    The US Department of Energy (DOE) needs to provide radiologically, and industrially safe and cost-effective management of the non-defense production reactor spent nuclear fuel (SNF) at the Hanford Site. The proposed action would place the Hanford Site`s non-defense production reactor SNF in a radiologically- and industrially-safe, and passive storage condition pending final disposition. The proposed action would also reduce operational costs associated with storage of the non-defense production reactor SNF through consolidation of the SNF and through use of passive rather than active storage systems. Environmental, safety and health vulnerabilities associated with existing non-defense production reactor SNF storage facilities have been identified. DOE has determined that additional activities are required to consolidate non-defense production reactor SNF management activities at the Hanford Site, including cost-effective and safe interim storage, prior to final disposition, to enable deactivation of facilities where the SNF is now stored. Cost-effectiveness would be realized: through reduced operational costs associated with passive rather than active storage systems; removal of SNF from areas undergoing deactivation as part of the Hanford Site remediation effort; and eliminating the need to duplicate future transloading facilities at the 200 and 400 Areas. Radiologically- and industrially-safe storage would be enhanced through: (1) removal from aging facilities requiring substantial upgrades to continue safe storage; (2) utilization of passive rather than active storage systems for SNF; and (3) removal of SNF from some storage containers which have a limited remaining design life. No substantial increase in Hanford Site environmental impacts would be expected from the proposed action. Environmental impacts from postulated accident scenarios also were evaluated, and indicated that the risks associated with the proposed action would be small.

  2. Decommissioning of eight surplus production reactors at the Hanford Site, Richland, Washington. Addendum (Final Environmental Impact Statement)

    SciTech Connect

    Not Available

    1992-12-01

    The first section of this volume summarizes the content of the draft environmental impact statement (DEIS) and this Addendum, which together constitute the final environmental impact statement (FEIS) prepared on the decommissioning of eight surplus plutonium production reactors at Hanford. The FEIS consists of two volumes. The first volume is the DEIS as written. The second volume (this Addendum) consists of a summary; Chapter 9, which contains comments on the DEIS and provides DOE`s responses to the comments; Appendix F, which provides additional health effects information; Appendix K, which contains costs of decommissioning in 1990 dollars; Appendix L, which contains additional graphite leaching data; Appendix M, which contains a discussion of accident scenarios; Appendix N, which contains errata; and Appendix 0, which contains reproductions of the letters, transcripts, and exhibits that constitute the record for the public comment period.

  3. Isotope Production at the Hanford Site in Richland, Washington

    SciTech Connect

    Ammoniums

    1999-06-01

    This report was prepared in response to a request from the Nuclear Energy Research Advisory Committee (NERAC) subcommittee on ''Long-Term Isotope Research and Production Plans.'' The NERAC subcommittee has asked for a reply to a number of questions regarding (1) ''How well does the Department of Energy (DOE) infrastructure sme the need for commercial and medical isotopes?'' and (2) ''What should be the long-term role of the federal government in providing commercial and medical isotopes?' Our report addresses the questions raised by the NERAC subcommittee, and especially the 10 issues that were raised under the first of the above questions (see Appendix). These issues are related to the isotope products offered by the DOE Isotope Production Sites, the capabilities and condition of the facilities used to produce these products, the management of the isotope production programs at DOE laboratories, and the customer service record of the DOE Isotope Production sites. An important component of our report is a description of the Fast Flux Test Facility (FFTF) reactor at the Hbford Site and the future plans for its utilization as a source of radioisotopes needed by nuclear medicine physicians, by researchers, and by customers in the commercial sector. In response to the second question raised by the NERAC subcommittee, it is our firm belief that the supply of isotopes provided by DOE for medical, industrial, and research applications must be strengthened in the near future. Many of the radioisotopes currently used for medical diagnosis and therapy of cancer and other diseases are imported from Canada, Europe, and Asia. This situation places the control of isotope availability, quality, and pricing in the hands of non-U.S. suppliers. It is our opinion that the needs of the U.S. customers for isotopes and isotope products are not being adequately served, and that the DOE infrastructure and facilities devoted to the supply of these products must be improved This perception forms one of the fundamental bases for our proposal that the FFTF, which is currently in a standby condition, be reactivated to supply nuclear services and products such as radioisotopes needed by the U.S. medical, industrial, and research communities.

  4. Operation of N Reactor and Fuels Fabrication Facilities, Hanford Reservation, Richland, Benton County, Washington: Environmental assessment

    SciTech Connect

    Not Available

    1980-08-01

    Environmental data, calculations and analyses show no significant adverse radiological or nonradiological impacts from current or projected future operations resulting from N Reactor, Fuels Fabrication and Spent Fuel Storage Facilities. Nonoccupational radiation exposures resulting from 1978 N Reactor operations are summarized and compared to allowable exposure limits.

  5. Environmental Assessment: Relocation and storage of TRIGA{reg_sign} reactor fuel, Hanford Site, Richland, Washington

    SciTech Connect

    1995-08-01

    In order to allow the shutdown of the Hanford 308 Building in the 300 Area, it is proposed to relocate fuel assemblies (101 irradiated, three unirradiated) from the Mark I TRIGA Reactor storage pool. The irradiated fuel assemblies would be stored in casks in the Interim Storage Area in the Hanford 400 Area; the three unirradiated ones would be transferred to another TRIGA reactor. The relocation is not expected to change the offsite exposure from all Hanford Site 300 and 400 Area operations.

  6. Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington

    SciTech Connect

    Greenfield, Bryce A.

    2009-12-20

    A detailed instructional manual was created to guide criticality safety engineers through the process of designing a criticality alarm system (CAS) for Department of Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements were both addressed. A list of design tasks and technical subtasks are thoroughly analyzed to provide concise direction for how to complete the analysis. An example of the application of the design methodology, the Criticality Alarm System developed for the Radioisotope Production Laboratory (RPL) of Richland, Washington is also included. The analysis for RPL utilizes the Monte Carlo code MCNP5 for establishing detector coverage in the facility. Significant improvements to the existing CAS were made that increase the reliability, transparency, and coverage of the system.

  7. 11. Building Layout, 185189 D, U.S. Atomic Energy Commission, Richland ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Building Layout, 185-189 D, U.S. Atomic Energy Commission, Richland Operations Office, Dwg. No. H-1-14844, 1957. - D-Reactor Complex, Deaeration Plant-Refrigeration Buildings, Area 100-D, Richland, Benton County, WA

  8. Reactor production of Thoruim-229

    DOE PAGESBeta

    Boll, Rose Ann; Murphy, Karen E.; Denton, David L.; Tamara J. Haverlock; Garland, Marc A.; Mirzadeh, Saed; Hogle, Susan; Owens, Allison

    2016-05-03

    Limited availability of 229Th for clinical applications of 213Bi necessitates investigation of alternative production routes. In reactor production, 229Th is produced from neutron transmutation of 226Ra, 228Ra, 227Ac and 228Th. Here, we evaluate irradiations of 226Ra, 228Ra, and 227Ac targets at the ORNL High Flux Isotope Reactor.

  9. Hanford production reactor heat releases 1951--1971

    SciTech Connect

    Kannberg, L.D.

    1992-04-01

    The purpose of this report is to document and detail the thermal releases from the Hanford nuclear production reactors during the period 1951 through 1971, and to put these releases in historical perspective with respect to changing Columbia River flows and temperatures. This information can also be used as a foundation for further ecological evaluations. When examining Hanford production reactor thermal releases to the Columbia River all related factors affecting the releases and the characteristics of the river should be considered. The major considerations in the present study were the characteristics of the releases themselves (primarily coolant flow rate, temperatures, discharge facilities, period of operation, and level of operation) and the characteristics of the river in that reach (primarily flow rate, temperature and mixing characteristics; the effects of dam construction were also taken into account). In addition, this study addressed ecological effects of thermal releases on aquatic species. Accordingly, this report includes discussion of the reactor cooling system, historical heat releases, thermal mixing and transport studies, hydroelectric power development, and ecologic effects of Hanford production reactor heat releases on salmon and trout. Appendix A contains reactor operating statistics, and Appendix B provide computations of heat added to the Columbia River between Priest Rapids Dam and Richland, Washington.

  10. Savannah River Site production reactor technical specifications. K Production Reactor

    SciTech Connect

    1996-02-01

    These technical specifications are explicit restrictions on the operation of the Savannah River Site K Production Reactor. They are designed to preserve the validity of the plant safety analysis by ensuring that the plant is operated within the required conditions bounded by the analysis, and with the operable equipment that is assumed to mitigate the consequences of an accident. Technical specifications preserve the primary success path relied upon to detect and respond to accidents. This report describes requirements on thermal-hydraulic limits; limiting conditions for operation and surveillance for the reactor, power distribution control, instrumentation, process water system, emergency cooling and emergency shutdown systems, confinement systems, plant systems, electrical systems, components handling, and special test exceptions; design features; and administrative controls.

  11. Safety issues at the defense production reactors

    SciTech Connect

    Not Available

    1987-01-01

    The United States produces plutonium and tritium for use in nuclear weapons at the defense production reactors - the N Reactor in Washington and the Savannah River reactors in South Carolina. This report reaches general conclusions about the management of those reactors and highlights a number of safety and technical issues that should be resolved. The report provides an assessment of the safety management, safety review, and safety methodology employed by the Department of Energy and the private contractors who operate the reactors for the federal government. This report examines the safety objective established by the Department of Energy for the production reactors and the process the Department of its contractors use to implement the objective; focuses on a variety of uncertainties concerning the production reactors, particularly those related to potential vulnerabilities to severe accidents; and identifies ways in which the DOE approach to management of the safety of the production reactors can be improved.

  12. New Production Reactors Program Plan

    SciTech Connect

    Not Available

    1990-12-01

    Part I of this New Production Reactors (NPR) Program Plan: describes the policy basis of the NPR Program; describes the mission and objectives of the NPR Program; identifies the requirements that must be met in order to achieve the mission and objectives; and describes and assesses the technology and siting options that were considered, the Program's preferred strategy, and its rationale. The implementation strategy for the New Production Reactors Program has three functions: Linking the design, construction, operation, and maintenance of facilities to policies requirements, and the process for selecting options. The development of an implementation strategy ensures that activities and procedures are consistent with the rationale and analysis underlying the Program. Organization of the Program. The strategy establishes plans, organizational structure, procedures, a budget, and a schedule for carrying out the Program. By doing so, the strategy ensures the clear assignment of responsibility and accountability. Management and monitoring of the Program. Finally, the strategy provides a basis for monitoring the Program so that technological, cost, and scheduling issues can be addressed when they arise as the Program proceeds. Like the rest of the Program Plan, the Implementation Strategy is a living document and will be periodically revised to reflect both progress made in the Program and adjustments in plans and policies as they are made. 21 figs., 5 tabs.

  13. Characterization of stored defense production spent nulcear fuel and associated materials at Hanford Site, Richland Washington: Environmental assessment

    SciTech Connect

    1995-03-01

    There are about 2,100 tonnes (2,300 tons) of defense production spent nuclear fuel stored in the 100-K Area Basins located along the south shore of the Columbia River in the northern part of the Hanford Site. Some of the fuel which has been in storage for a number of years is in poor condition and continues to deteriorate. The basins also contain fuel fragments and radioactively contaminated sludge. The DOE needs to characterize defense production spent nuclear fuel and associated materials stored on the Hanford Site. In order to satisfy that need, the Department of Energy (DOE) proposes to select, collect and transport samples of spent nuclear fuel and associated materials to the 327 Building for characterization. As a result of that characterization, modes of interim storage can be determined that would be compatible with the material in its present state and alternative treatment processes could be developed to permit a broader selection of storage modes. Environmental impacts of the proposed action were determined to be limited principally to radiation exposure of workers, which, however, were found to be small. No health effects among workers or the general public would be expected under routine operations. Implementation of the proposed action would not result in any impacts on cultural resources, threatened, endangered and candidate species, air or water quality, socioeconomic conditions, or waste management.

  14. Richland Operations Office technology summary

    SciTech Connect

    Not Available

    1994-05-01

    This document has been prepared by the Department of Energy`s Environmental Management Office of Technology Development to highlight its research, development, demonstration, testing, and evaluation activities funded through the Richland Operations Office. Technologies and processes described have the potential to enhance cleanup and waste management efforts.

  15. The economic and community impacts of closing Hanford's N Reactor and nuclear materials production facilities

    SciTech Connect

    Scott, M.J.; Belzer, D.B.; Nesse, R.J.; Schultz, R.W.; Stokowski, P.A.; Clark, D.C.

    1987-08-01

    This study discusses the negative economic impact on local cities and counties and the State of Washington of a permanent closure of nuclear materials production at the Hanford Site, located in the southeastern part of the state. The loss of nuclear materials production, the largest and most important of the five Department of Energy (DOE) missions at Hanford, could occur if Hanford's N Reactor is permanently closed and not replaced. The study provides estimates of statewide and local losses in jobs, income, and purchases from the private sector caused by such an event; it forecasts impacts on state and local government finances; and it describes certain local community and social impacts in the Tri-Cities (Richland, Kennewick, and Pasco) and surrounding communities. 33 refs., 8 figs., 22 tabs.

  16. Safe new reactor for radionuclide production

    SciTech Connect

    Gray, P.L.

    1995-02-15

    In late 1995, DOE is schedule to announce a new tritium production unit. Near the end of the last NPR (New Production Reactors) program, work was directed towards eliminating risks in current designs and reducing effects of accidents. In the Heavy Water Reactor Program at Savannah River, the coolant was changed from heavy to light water. An alternative, passively safe concept uses a heavy-water-filled, zircaloy reactor calandria near the bottom of a swimming pool; the calandria is supported on a light-water-coolant inlet plenum and has upflow through assemblies in the calandria tubes. The reactor concept eliminates or reduces significantly most design basis and severe accidents that plague other deigns. The proven, current SRS tritium cycle remains intact; production within the US of medical isotopes such as Mo-99 would also be possible.

  17. Synfuel production in nuclear reactors

    DOEpatents

    Henning, C.D.

    Apparatus and method for producing synthetic fuels and synthetic fuel components by using a neutron source as the energy source, such as a fusion reactor. Neutron absorbers are disposed inside a reaction pipe and are heated by capturing neutrons from the neutron source. Synthetic fuel feedstock is then placed into contact with the heated neutron absorbers. The feedstock is heated and dissociates into its constituent synfuel components, or alternatively is at least preheated sufficiently to use in a subsequent electrolysis process to produce synthetic fuels and synthetic fuel components.

  18. The Modular Helium Reactor for Hydrogen Production

    SciTech Connect

    E. Harvego; M. Richards; A. Shenoy; K. Schultz; L. Brown; M. Fukuie

    2006-10-01

    For electricity and hydrogen production, an advanced reactor technology receiving considerable international interest is a modular, passively-safe version of the high-temperature, gas-cooled reactor (HTGR), known in the U.S. as the Modular Helium Reactor (MHR), which operates at a power level of 600 MW(t). For hydrogen production, the concept is referred to as the H2-MHR. Two concepts that make direct use of the MHR high-temperature process heat are being investigated in order to improve the efficiency and economics of hydrogen production. The first concept involves coupling the MHR to the Sulfur-Iodine (SI) thermochemical water splitting process and is referred to as the SI-Based H2-MHR. The second concept involves coupling the MHR to high-temperature electrolysis (HTE) and is referred to as the HTE-Based H2-MHR.

  19. Alternatives to proposed replacement production reactors

    SciTech Connect

    Cullingford, H.S.

    1981-06-01

    To insure adequate supplies of plutonium and tritium for defense purposes, an independent evaluation was made by Los Alamos National Laboratory of the numerous alternatives to the proposed replacement production reactors (RPR). This effort concentrated on the defense fuel cycle operation and its technical implications in identifying the principal alternatives for the 1990s. The primary options were identified as (1) existing commercial reactors, (2) existing and planned government-owned facilities (not now used for defense materials production), and (3) other RPRs (not yet proposed) such as CANDU or CANDU-type heavy-water reactors (HWR) for both plutonium and tritium production. The evaluation considered features and differences of various options that could influence choice of RPR alternatives. Barring a change in the US approach to civilian and defense fuel cycles and precluding existing commercial reactors at government-owned sites, the most significant alternatives were identified as a CANDU-type HWR at Savannah River Plant (SRP) site or the Three Mile Island commercial reactor with reprocessing capability at Barnwell Nuclear Fuel Plant and at SRP.

  20. Pebble Bed Reactor Dust Production Model

    SciTech Connect

    Abderrafi M. Ougouag; Joshua J. Cogliati

    2008-09-01

    The operation of pebble bed reactors, including fuel circulation, can generate graphite dust, which in turn could be a concern for internal components; and to the near field in the remote event of a break in the coolant circuits. The design of the reactor system must, therefore, take the dust into account and the operation must include contingencies for dust removal and for mitigation of potential releases. Such planning requires a proper assessment of the dust inventory. This paper presents a predictive model of dust generation in an operating pebble bed with recirculating fuel. In this preliminary work the production model is based on the use of the assumption of proportionality between the dust production and the normal force and distance traveled. The model developed in this work uses the slip distances and the inter-pebble forces computed by the authors’ PEBBLES. The code, based on the discrete element method, simulates the relevant static and kinetic friction interactions between the pebbles as well as the recirculation of the pebbles through the reactor vessel. The interaction between pebbles and walls of the reactor vat is treated using the same approach. The amount of dust produced is proportional to the wear coefficient for adhesive wear (taken from literature) and to the slip volume, the product of the contact area and the slip distance. The paper will compare the predicted volume with the measured production rates. The simulation tallies the dust production based on the location of creation. Two peak production zones from intra pebble forces are predicted within the bed. The first zone is located near the pebble inlet chute due to the speed of the dropping pebbles. The second peak zone occurs lower in the reactor with increased pebble contact force due to the weight of supported pebbles. This paper presents the first use of a Discrete Element Method simulation of pebble bed dust production.

  1. Volatility of fission products during reactor accidents

    NASA Astrophysics Data System (ADS)

    Paquette, J.; Torgerson, D. F.; Wren, J. C.; Wren, D. J.

    1985-02-01

    This paper summarizes some current generic work on the behaviour of iodine, cesium, and tellurium under conditions expected to occur during postulated reactor accidents. We discuss Knudsen cell experiments to elucidate the high-temperature properties of fission-product mixtures, steam-flashing experiments to measure iodine transfer to the gas phase, and the formation and volatility of organic iodides in aqueous solutions.

  2. Biodiesel production using a membrane reactor.

    PubMed

    Dubé, M A; Tremblay, A Y; Liu, J

    2007-02-01

    The immiscibility of canola oil in methanol provides a mass-transfer challenge in the early stages of the transesterification of canola oil in the production of fatty acid methyl esters (FAME or biodiesel). To overcome or rather, exploit this situation, a two-phase membrane reactor was developed to produce FAME from canola oil and methanol. The transesterification of canola oil was performed via both acid- or base-catalysis. Runs were performed in the membrane reactor in semi-batch mode at 60, 65 and 70 degrees C and at different catalyst concentrations and feed flow rates. Increases in temperature, catalyst concentration and feedstock (methanol/oil) flow rate significantly increased the conversion of oil to biodiesel. The novel reactor enabled the separation of reaction products (FAME/glycerol in methanol) from the original canola oil feed. The two-phase membrane reactor was particularly useful in removing unreacted canola oil from the FAME product yielding high purity biodiesel and shifting the reaction equilibrium to the product side. PMID:16580197

  3. Silicon production in a fluidized bed reactor

    NASA Technical Reports Server (NTRS)

    Rohatgi, N. K.

    1986-01-01

    Part of the development effort of the JPL in-house technology involved in the Flat-Plate Solar Array (FSA) Project was the investigation of a low-cost process to produce semiconductor-grade silicon for terrestrial photovoltaic cell applications. The process selected was based on pyrolysis of silane in a fluidized-bed reactor (FBR). Following initial investigations involving 1- and 2-in. diameter reactors, a 6-in. diameter, engineering-scale FBR was constructed to establish reactor performance, mechanism of silicon deposition, product morphology, and product purity. The overall mass balance for all experiments indicates that more than 90% of the total silicon fed into the reactor is deposited on silicon seed particles and the remaining 10% becomes elutriated fines. Silicon production rates were demonstrated of 1.5 kg/h at 30% silane concentration and 3.5 kg/h at 80% silane concentration. The mechanism of silicon deposition is described by a six-path process: heterogeneous deposition, homogeneous decomposition, coalescence, coagulation, scavenging, and heterogeneous growth on fines. The bulk of the growth silicon layer appears to be made up of small diameter particles. This product morphology lends support to the concept of the scavenging of homogeneously nucleated silicon.

  4. Production of 89Sr in solution reactor.

    PubMed

    Chuvilin, D Yu; Khvostionov, V E; Markovskij, D V; Pavshook, V A; Ponomarev-Stepnoy, N N; Udovenko, A N; Shatrov, A V; Vereschagin, Yu I; Rice, J; Tome, L A

    2007-10-01

    The new method for medical (89)Sr production in a reactor with solution fuel is proposed which is characterized by simplicity, high production efficiency and low buildup of radioactive waste. The main advantages of the new technology were validated by numerous experiments. The proposed new technology selectively extracts (89)Sr from a fuel of solution reactor and precludes penetration of (90)Sr into the final product. This method is based on the presence of gaseous radionuclide (89)Kr (T(1/2)=190.7s) in the decay chain (89)Se-->(89)Br-->(89)Kr-->(89)Rb-->(89)Sr. The performed experiments on taking the gas probes from internal volume of the solution 20 kW mini-reactor "Argus" have confirmed that the mechanism for (89)Sr delivery to the sorption volume of the reactor experimental loop is based on transport of gaseous (89)Sr predecessor-radionuclide (89)Kr. According to the measurements of radioactive impurities in a final (89)SrCl(2) solution, the filtration of the gas flow with cermet filters followed by cleaning of (89)Sr chloride solution in chromatographic columns with DOWEX-50 x 8 or Sr-Resin ensures reception of (89)Sr fully meeting the requirements for medical application. The experimental estimations have shown that the proposed new technology is multiply more productive than the traditional industrial methods of (89)Sr reception. PMID:17611114

  5. Reactors Save Energy, Costs for Hydrogen Production

    NASA Technical Reports Server (NTRS)

    2014-01-01

    While examining fuel-reforming technology for fuel cells onboard aircraft, Glenn Research Center partnered with Garrettsville, Ohio-based Catacel Corporation through the Glenn Alliance Technology Exchange program and a Space Act Agreement. Catacel developed a stackable structural reactor that is now employed for commercial hydrogen production and results in energy savings of about 20 percent.

  6. Draft environmental impact statement for the siting, construction, and operation of New Production Reactor capacity. Volume 1, Summary

    SciTech Connect

    Not Available

    1991-04-01

    This Environmental Impact Statement (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site near Aiken, South Carolina. The EIS programmatic alternatives address Departmental decisions to be made on whether to build new production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public.

  7. Draft environmental impact statement siting, construction, and operation of New Production Reactor capacity. Volume 4, Appendices D-R

    SciTech Connect

    1991-04-01

    This Environmental Impact Statement (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site near Aiken, South Carolina. The EIS programmatic alternatives address Departmental decisions to be made on whether to build new production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public. This volume contains 15 appendices.

  8. Hydrogen Production Using the Modular Helium Reactor

    SciTech Connect

    E. A. Harvego; S. M. Reza; M. Richards; A. Shenoy

    2005-05-01

    The high-temperature characteristics of the Modular Helium Reactor (MHR) make it a strong candidate for the production of hydrogen using either thermochemical or high-temperature electrolysis (HTE) processes. Using heat from the MHR to drive a Sulfur-Iodine (S-I) thermochemical hydrogen process has been the subject of a DOE sponsored Nuclear Engineering Research Initiative (NERI) project lead by General Atomics, with participation from the Idaho National Engineering and Environmental Laboratory (INEEL) and Texas A&M University. While the focus of much of the initial work was on the S-I thermochemical production of hydrogen, recent activities have also included development of a preconceptual design for an integral HTE hydrogen production plant driven by the process heat and electricity produced by a 600 MWt MHR. This paper describes RELAP5-3D analyses performed to evaluate alternative primary system cooling configurations for the MHR to minimize peak reactor vessel and core temperatures while achieving core helium outlet temperatures in the range of 900 oC to 1000 oC, needed for the efficient production of hydrogen using either the S-I thermochemical or HTE process. The cooling schemes investigated are intended to ensure peak fuel temperatures do not exceed specified limits under normal or transient upset conditions, and that reactor vessel temperatures do not exceed ASME code limits for steady-state or transient conditions using standard LWR vessel materials. Preconceptual designs for both an S-I thermochemical and HTE hydrogen production plant driven by a 600 MWt MHR at helium outlet temperatures in the range of 900 oC to 1000 oC are described and compared. An initial SAPHIRE model to evaluate the reliability, maintainablility, and availability of the S-I hydrogen production plant is also discussed, and plans for future assessments of conceptual designs for both a S-I thermochemical and HTE hydrogen production plant coupled to a 600 MWt modular helium reactor are described.

  9. NPR (New Production Reactor) capacity cost evaluation

    SciTech Connect

    1988-07-01

    The ORNL Cost Evaluation Technical Support Group (CETSG) has been assigned by DOE-HQ Defense Programs (DP) the task defining, obtaining, and evaluating the capital and life-cycle costs for each of the technology/proponent/site/revenue possibilities envisioned for the New Production Reactor (NPR). The first part of this exercise is largely one of accounting, since all NPR proponents use different accounting methodologies in preparing their costs. In order to address this problem of comparing ''apples and oranges,'' the proponent-provided costs must be partitioned into a framework suitable for all proponents and concepts. If this is done, major cost categories can then be compared between concepts and major cost differences identified. Since the technologies proposed for the NPR and its needed fuel and target support facilities vary considerably in level of technical and operational maturity, considerable care must be taken to evaluate the proponent-derived costs in an equitable manner. The use of cost-risk analysis along with derivation of single point or deterministic estimates allows one to take into account these very real differences in technical and operational maturity. Chapter 2 summarizes the results of this study in tabular and bar graph form. The remaining chapters discuss each generic reactor type as follows: Chapter 3, LWR concepts (SWR and WNP-1); Chapter 4, HWR concepts; Chapter 5, HTGR concept; and Chapter 6, LMR concept. Each of these chapters could be a stand-alone report. 39 refs., 36 figs., 115 tabs.

  10. RACEWAY REACTOR FOR MICROALGAL BIODIESEL PRODUCTION

    EPA Science Inventory

    The proposed mathematical model incorporating mass transfer, hydraulics, carbonate/aquatic chemistry, biokinetics, biology and reactor design will be calibrated and validated using the data to be generated from the experiments. The practical feasibility of the proposed reactor...

  11. Immobilized cell reactor with simultaneous product separation. 1. Reactor design and analysis

    SciTech Connect

    Dale, M.C.; Okos, M.R.; Wanket, P.C.

    1985-07-01

    A four-phase reactor-separator(gas, liquid, solid, and immobilized catalyst) is proposed for fermentations characterized by a volatile product and nonvolatile substrate. In this reactor, the biological catalyst is immobilized onto a solid column packing and contacted by the liquid containing the substrate. A gas phase is also moved through the column to strip the volatile product into the gas phase. The Immobilized Cell Reactor-Separator (ICRS) consists of two basic gas-liquid flow sections: a cocurrent enricher followed by a countercurrent-stripper. In this article, an equilibrium stage model of the reactor is developed to determine the feasibility and important operational variables of such a reactor-separator. The ICRS concept is applied to the ethanol from whey lactose fermentation using some preliminary immobilized cell reactor performance data. A mathematical model for a steady-state population based on an adsorbed monolayer of cells is also developed for the reactor. The ICRS model demonstrated that the ICRS should give a significant increase in reactor productivity as compared to an identically sized immobilized cell reactor (ICR) with no separation. The gas-phase separation of the product also allows fermentation of high inlet substrate concentrations. The model is used to determine the effects of reactor parameters on ICRS performance including temperature, pressure, gas flow rates, inlet substrate concentration, and degree of microbial product inhibition.

  12. An immobilized cell reactor with simultaneous product separation. I. Reactor design and analysis.

    PubMed

    Dale, M C; Okos, M R; Wankat, P C

    1985-07-01

    A four-phase reactor-separator (gas, liquid, solid, and immobilized catalyst) is proposed for fermentations characterized by a volatile product and nonvolatile substrate.In this reactor, the biological catalyst is immobilized onto a solid column packing and contacted by the liquid containing the substrate.A gas phase is also moved through the column to strip the volatile product into the gas phase. The Immobilized Cell Reactor-Separator (ICRS) consists of two basic gas-liquid flow sections: a cocurrent "enricher" followed by a countercurrent-"stripper".In this article, an equilibrium stage model of the reactor is developed to determine the feasibility and important operational variables of such a reactor-separator. The ICRS concept is applied to the ethanol from whey lactose fermentation using some preliminary immobilized cell reactor performance data. A mathematical model for a steady-state population based on an adsorbed monolayer of cells is also developed for the reactor. The ICRS model demonstrated that the ICRS should give a significant increase in reactor productivity as compared to an identically sized Immobilized Cell Reactor (ICR) with no separation. The gas-phase separation of the product also allows fermentation of high inlet substrate concentrations. The model is used to determine the effects of reactor parameters on ICRS performance including temperature, pressure, gas flow rates, inlet substrate concentration, and degree of microbial product inhibition. PMID:18553762

  13. POTENTIAL BENCHMARKS FOR ACTINIDE PRODUCTION IN HANFORD REACTORS

    SciTech Connect

    PUIGH RJ; TOFFER H

    2011-10-19

    A significant experimental program was conducted in the early Hanford reactors to understand the reactor production of actinides. These experiments were conducted with sufficient rigor, in some cases, to provide useful information that can be utilized today in development of benchmark experiments that may be used for the validation of present computer codes for the production of these actinides in low enriched uranium fuel.

  14. Draft environmental impact statement for the siting, construction, and operation of New Production Reactor capacity. Volume 2, Sections 1-6

    SciTech Connect

    Not Available

    1991-04-01

    This (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site. The EIS programmatic alternatives address Departmental decisions to be made on whether to build new production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public. This volume contains the analysis of programmatic alternatives, project alternatives, affected environment of alternative sites, environmental consequences, and environmental regulations and permit requirements.

  15. Draft environmental impact statement for the siting, construction, and operation of New Production Reactor capacity. Volume 3, Sections 7-12, Appendices A-C

    SciTech Connect

    Not Available

    1991-04-01

    This Environmental Impact Statement (EIS) assesses the potential environmental impacts, both on a broad programmatic level and on a project-specific level, concerning a proposed action to provide new tritium production capacity to meet the nation`s nuclear defense requirements well into the 21st century. A capacity equivalent to that of about a 3,000-megawatt (thermal) heavy-water reactor was assumed as a reference basis for analysis in this EIS; this is the approximate capacity of the existing production reactors at DOE`s Savannah River Site near Aiken, South Carolina. The EIS programmatic alternatives address Departmental decisions to be made on whether to build new production facilities, whether to build one or more complexes, what size production capacity to provide, and when to provide this capacity. Project-specific impacts for siting, constructing, and operating new production reactor capacity are assessed for three alternative sites: the Hanford Site near Richland, Washington; the Idaho National Engineering Laboratory near Idaho Falls, Idaho; and the Savannah River Site. For each site, the impacts of three reactor technologies (and supporting facilities) are assessed: a heavy-water reactor, a light-water reactor, and a modular high-temperature gas-cooled reactor. Impacts of the no-action alternative also are assessed. The EIS evaluates impacts related to air quality; noise levels; surface water, groundwater, and wetlands; land use; recreation; visual environment; biotic resources; historical, archaeological, and cultural resources; socioeconomics; transportation; waste management; and human health and safety. The EIS describes in detail the potential radioactive releases from new production reactors and support facilities and assesses the potential doses to workers and the general public. This volume contains references; a list of preparers and recipients; acronyms, abbreviations, and units of measure; a glossary; an index and three appendices.

  16. The behavior of fission products during nuclear rocket reactor tests

    SciTech Connect

    Bokor, P.C.; Kirk, W.L.; Bohl, R.J.

    1991-01-01

    The experience base regarding fission product behavior developed during the Rover program, the nuclear rocket development program of 1955--1972, will be useful in planning a renewed nuclear rocket program. During the Rover program, 20 reactors were tested at the Nuclear Rocket Development Station in Nevada. Nineteen of these discharged effluent directly into the atmosphere; the last reactor tested, a non-flight-prototypic, fuel-element-testing reactor called the Nuclear Furnace (NF-1) was connected to an effluent cleanup system that removed fission products before the hydrogen coolant (propellant) was discharged to the atmosphere. In general, we are able to increase both test duration and fuel temperature during the test series. Therefore fission product data from the later part of the program are more interesting and more applicable to future reactors. We have collected fission product retention (and release) data reported in both formal and informal publications for six of the later reactor tests; five of these were Los Alamos reactors that were firsts of a kind in configuration or operating conditions. We have also, with the cooperation of Westinghouse, included fission product data from the NRX-A6 reactor, the final member of series of developmental reactors with the same basic geometry, but with significant design and fabrication improvements as the series continued. Table 1 lists the six selected reactors and the test parameters for each.

  17. The behavior of fission products during nuclear rocket reactor tests

    NASA Astrophysics Data System (ADS)

    Bokor, Peter C.; Kirk, William L.; Bohl, Richard J.

    The experience base regarding fission product behavior developed during the Rover program, the nuclear rocket development program of 1955 to 1972 will be useful in planning a renewed nuclear rocket program. During the Rover program, 20 reactors were tested at the Nuclear Rocket Development Station in Nevada. Nineteen of these discharged effluent directly into the atmosphere; the last reactor tested, a non-flight-prototypic, fuel-element-testing reactor called the Nuclear Furnace (NF-1) was connected to an effluent cleanup system that removed fission products before the hydrogen coolant (propellant) was discharged to the atmosphere. In general, we are able to increase both test duration and fuel temperature during the test series. Therefore fission product data from the later part of the program are more interesting and more applicable to future reactors. We have collected fission product retention (and release) data reported in both formal and informal publications for six of the later reactor tests; five of these were Los Alamos reactors that were firsts of a kind in configuration or operating conditions. We have also, with the cooperation of Westinghouse, included fission product data from the NRX-A6 reactor, the final member of a series of developmental reactors with the same basic geometry, but with significant design and fabrication improvements as the series continued. Table 1 lists the six selected reactors and the test parameters for each.

  18. The effective management of medical isotope production in research reactors

    SciTech Connect

    Drummond, D.T. )

    1993-01-01

    During the 50-yr history of the use of radioisotopes for medical applications, research reactors have played a pivotal role in the production of many if not most of the key products. The marriage between research reactors and production operations is subject to significant challenges on two fronts. The medical applications of the radioisotope products impose some unique constraints and requirements on the production process. In addition, the mandates and priorities of a research reactor are not always congruent with the demands of a production environment. This paper briefly reviews the historical development of medical isotope production, identifies the unique challenges facing this endeavor, and discusses the management of the relationship between the isotope producer and the research reactor operator. Finally, the key elements of a successful relationship are identified.

  19. Aerosol reactor production of uniform submicron powders

    DOEpatents

    Flagan, Richard C.; Wu, Jin J.

    1991-02-19

    A method of producing submicron nonagglomerated particles in a single stage reactor includes introducing a reactant or mixture of reactants at one end while varying the temperature along the reactor to initiate reactions at a low rate. As homogeneously small numbers of seed particles generated in the initial section of the reactor progress through the reactor, the reaction is gradually accelerated through programmed increases in temperature along the length of the reactor to promote particle growth by chemical vapor deposition while minimizing agglomerate formation by maintaining a sufficiently low number concentration of particles in the reactor such that coagulation is inhibited within the residence time of particles in the reactor. The maximum temperature and minimum residence time is defined by a combination of temperature and residence time that is necessary to bring the reaction to completion. In one embodiment, electronic grade silane and high purity nitrogen are introduced into the reactor and temperatures of approximately 770.degree. K. to 1550.degree. K. are employed. In another embodiment silane and ammonia are employed at temperatures from 750.degree. K. to 1800.degree. K.

  20. Aerosol reactor production of uniform submicron powders

    NASA Technical Reports Server (NTRS)

    Flagan, Richard C. (Inventor); Wu, Jin J. (Inventor)

    1991-01-01

    A method of producing submicron nonagglomerated particles in a single stage reactor includes introducing a reactant or mixture of reactants at one end while varying the temperature along the reactor to initiate reactions at a low rate. As homogeneously small numbers of seed particles generated in the initial section of the reactor progress through the reactor, the reaction is gradually accelerated through programmed increases in temperature along the length of the reactor to promote particle growth by chemical vapor deposition while minimizing agglomerate formation by maintaining a sufficiently low number concentration of particles in the reactor such that coagulation is inhibited within the residence time of particles in the reactor. The maximum temperature and minimum residence time is defined by a combination of temperature and residence time that is necessary to bring the reaction to completion. In one embodiment, electronic grade silane and high purity nitrogen are introduced into the reactor and temperatures of approximately 770.degree. K. to 1550.degree. K. are employed. In another embodiment silane and ammonia are employed at temperatures from 750.degree. K. to 1800.degree. K.

  1. Aerosol reactor production of uniform submicron powders

    SciTech Connect

    Flagan, R.C.; Wu, J.J.

    1991-02-19

    A method of producing submicron non agglomerated particles in a single stage reactor includes introducing a reactant or mixture of reactants at one end while varying the temperature along the reactor to initiate reactions at a low rate. As homogeneously small numbers of seed particles generated in the initial section of the reactor progress through the reactor, the reaction is gradually accelerated through programmed increases in temperature along the length of the reactor to promote particle growth by chemical vapor deposition while minimizing agglomerate formation by maintaining a sufficiently low number concentration of particles in the reactor such that coagulation is inhibited within the residence time of particles in the reactor. The maximum temperature and minimum residence time is defined by a combination of temperature and residence time that is necessary to bring the reaction to completion. In one embodiment, electronic grade silane and high purity nitrogen are introduced into the reactor and temperatures of approximately 770 K to 1550 K are employed. In another embodiment silane and ammonia are employed at temperatures from 750 K to 1800 K. 7 figures.

  2. Supplying the nuclear arsenal: American production reactors, 1942--1992

    SciTech Connect

    Carlisle, R.P.; Zenzen, J.M.

    1996-01-01

    Although the history of commercial-power nuclear reactors is well known, the story of the government reactors that produce weapons-grade plutonium and tritium has been shrouded in secrecy. In the first detailed look at the origin and development of these production reactors, the authors describe a fifty-year government effort no less complex, expensive, and technologically demanding than the Polaris or Apollo programs--yet one about which most Americans know virtually nothing. The book describes the evolution of the early reactors, the atomic weapons establishment that surrounded them, and the sometimes bitter struggles between business and political constituencies for their share of 'nuclear pork.' They show how, since the 1980s, aging production reactors have increased the risk of radioactive contamination of the atmosphere and water table. And they describe how the Department of Energy mounted a massive effort to find the right design for a new generation of reactors, only to abandon that effort with the end of the Cold War. Today, all American production reactors remain closed. Due to short half-life, the nation's supply of tritium, crucial to modern weapons, is rapidly dwindling. As countries like Iraq and North Korea threaten to join the nuclear club, the authors contend, the United States needs to revitalize tritium production capacity in order to maintain a viable nuclear deterrent. Meanwhile, as slowly decaying artifacts of the Cold War, the closed production reactors at Hanford, Washington, and Savannah River, South Carolina, loom ominously over the landscape.

  3. Continuous production of tritium in an isotope-production reactor with a separate circulation system

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium is allowed to flow through the reactor in separate loops in order to facilitate the production and removal of tritium.

  4. Corrosion-product release in light water reactors

    SciTech Connect

    Lister, D.H.

    1984-03-01

    This research project is aimed at studying corrosion-product release from a range of reactor alloys under both PWR and BWR coolant chemistry conditions. The results of such a study will be ued to recommend ways by which corrosion-product release, and subsequent radiation fields, can be minimized in reactors. The investigation of corrosion-product release has so far employed three main techniques: in-reactor loop experiments to provide data on the effects of coolant chemistry and reactor irradiation; out-reactor loop experiments to provide kinetics data on release; and a combined radiotracer-surface analytical study of oxide films to provide mechanistic information on release. The results of the first year of the program are presented and discussed.

  5. Small Reactor for Semiconductor Production by Neutron Transmutation Doping

    NASA Astrophysics Data System (ADS)

    Obara, Toru; Hong, Liem Peng

    2010-06-01

    New concept of small size nuclear reactor is proposed for Neutron Transmutation Doping (NTD). The reactor core consists of conventional PWR type fuel elements with light water moderator/coolant unlike conventional research reactors. Graphite reflector is employed for large neutron irradiation volume. Silicon ingots are put into the reflector region for irradiation. Neutronic analysis results show that this concept has possibility to product large amount of silicon ingots which have large diameter. An optimal reactor design and its performance are shown as a result of analysis in the paper.

  6. Method of producing gaseous products using a downflow reactor

    SciTech Connect

    Cortright, Randy D; Rozmiarek, Robert T; Hornemann, Charles C

    2014-09-16

    Reactor systems and methods are provided for the catalytic conversion of liquid feedstocks to synthesis gases and other noncondensable gaseous products. The reactor systems include a heat exchange reactor configured to allow the liquid feedstock and gas product to flow concurrently in a downflow direction. The reactor systems and methods are particularly useful for producing hydrogen and light hydrocarbons from biomass-derived oxygenated hydrocarbons using aqueous phase reforming. The generated gases may find used as a fuel source for energy generation via PEM fuel cells, solid-oxide fuel cells, internal combustion engines, or gas turbine gensets, or used in other chemical processes to produce additional products. The gaseous products may also be collected for later use or distribution.

  7. Homogeneous fast-flux isotope-production reactor

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a liquid metal fast breeder reactor. Lithium target material is dissolved in the liquid metal coolant in order to facilitate the production and removal of tritium.

  8. Survey of Dust Production in Pebble Bed Reactors Cores

    SciTech Connect

    Joshua J. Cogliati; Abderafi M. Ougouag; Javier Ortensi

    2011-06-01

    Graphite dust produced via mechanical wear from the pebbles in a pebble bed reactor is an area of concern for licensing. Both the German pebble bed reactors produced graphite dust that contained activated elements. These activation products constitute an additional source term of radiation and must be taken under consideration during the conduct of accident analysis of the design. This paper discusses the available literature on graphite dust production and measurements in pebble bed reactors. Limited data is available on the graphite dust produced from the AVR and THTR-300 pebble bed reactors. Experiments that have been performed on wear of graphite in pebble-bed-like conditions are reviewed. The calculation of contact forces, which are a key driving mechanism for dust in the reactor, are also included. In addition, prior graphite dust predictions are examined, and future areas of research are identified.

  9. Production capabilities in US nuclear reactors for medical radioisotopes

    SciTech Connect

    Mirzadeh, S.; Callahan, A.P.; Knapp, F.F. Jr.; Schenter, R.E.

    1992-11-01

    The availability of reactor-produced radioisotopes in the United States for use in medical research and nuclear medicine has traditionally depended on facilities which are an integral part of the US national laboratories and a few reactors at universities. One exception is the reactor in Sterling Forest, New York, originally operated as part of the Cintichem (Union Carbide) system, which is currently in the process of permanent shutdown. Since there are no industry-run reactors in the US, the national laboratories and universities thus play a critical role in providing reactor-produced radioisotopes for medical research and clinical use. The goal of this survey is to provide a comprehensive summary of these production capabilities. With the temporary shutdown of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) in November 1986, the radioisotopes required for DOE-supported radionuclide generators were made available at the Brookhaven National Laboratory (BNL) High Flux Beam Reactor (HFBR). In March 1988, however, the HFBR was temporarily shut down which forced investigators to look at other reactors for production of the radioisotopes. During this period the Missouri University Research Reactor (MURR) played an important role in providing these services. The HFIR resumed routine operation in July 1990 at 85 MW power, and the HFBR resumed operation in June 1991, at 30 MW power. At the time of the HFBR shutdown, there was no available comprehensive overview which could provide information on status of the reactors operating in the US and their capabilities for radioisotope production. The obvious need for a useful overview was thus the impetus for preparing this survey, which would provide an up-to-date summary of those reactors available in the US at both the DOE-funded national laboratories and at US universities where service irradiations are currently or expected to be conducted.

  10. NOVEL REACTOR DESIGN FOR BIODIESEL PRODUCTION

    EPA Science Inventory

    The goal of this project is to scale-up a novel reactor for producing Biodiesel from alternative feedstocks. Biodiesel is an alternative fuel that can be produced from a wide variety of plant oils, animal oils and waste oils from food processing. The conventional feedstocks fo...

  11. Production of primary pyrolysis oils in a vortex reactor

    SciTech Connect

    Diebold, J.; Scahill, J.

    1987-04-01

    A vortex tube has certain advantages as a chemical reactor, especially if the reactions are endothermic, the reaction pathways are temperature dependent, and the products are temperature sensitive. With low temperature differences, the vortex reactor can transmit enormous heat fluxes to a process stream containing entrained solids. This reactor has nearly plug flow and is ideally suited for the production of pyrolysis oils from biomass at low pressures and residence times to produce about 10 wt % char, 13% water, 7% gas, and 70% oxygenated primary oil vapors based on mass balances. This product distribution was verified by carbon, hydrogen, and oxygen elemental balances. The oil production appears to form by fragmenting all of the major constituents of the biomass.

  12. Chemistry of fission product iodine under nuclear reactor accident conditions

    SciTech Connect

    Malinauskas, A.P.; Bell, J.T.

    1986-01-01

    The radioisotopes of iodine are generally acknowledged to be the species whose release into the biosphere as a result of a nuclear reactor accident is of the greatest concern. In the course of its release, the fission product is subjected to differing chemical environments; these can alter the physicochemical form of the fission product and thus modify the manner and extent to which release occurs. Both the chemical environments which are characteristic of reactor accidents and their effect in determining physical and chemical form of fission product iodine have been studied extensively, and are reviewed in this report. 76 refs.

  13. Immobilized cell reactor with simultaneous product separation. II. Experimental reactor performance

    SciTech Connect

    Dale, M.C.; Okos, M.R.; Wankat, P.C.

    1985-07-01

    The Immobilized Cell Reactor-Separator (ICRS) consists of two column reactors: a cocurrent gas-liquid enricher followed by a countercurrent stripper. The columns are four-phase tubular reactors consisting of 1) an inert gas phase, 2) the liquid fermentation broth, 3) the solid column internal packing, and 4) the immobilized biological catalyst or cells. The application of the ICRS to the ethanol-from-whey-lactose fermentation system has been investigated. Operation in the liquid continuous or bubble flow regime allows a high liquid holdup in the reactor and consequent long and controllable liquid residence time but results in a high gas phase pressure drop over the length of the reactor and low gas flow rates. Operation in the gas continuous regime gives high gas flow rates and low pressure drop but also results in short liquid residence time and incomplete column wetting at low liquid loading rates using conventional gas-liquid column packings. Using cells absorbed to conventional ceramic column packing (0.25-in Intalox saddles), it was found that a good reaction could be obtained in the liquid continuous mode, but little separation, while in the gas continuous mode there was little reaction but good separation. Using cells sorbed to an absorbant matrix allowed operation in the gas continuous regime with a liquid holdup of up to 30% of the total reactor volume. Good reaction rates and product separation were obtained using this matrix. High reaction rates were obtained due to high density cell loading in the reactor. A dry cell density of up to 92 g/l reactor was obtained in the enricher. The enricher ethanol productivity ranged from 50 to 160 g/l h while the stripper productivity varied from 0 to 32 g/l h at different feed rates and concentrations. A separation efficiency of as high as 98% was obtained from the system.

  14. Feasibility study of a magnetic fusion production reactor

    NASA Astrophysics Data System (ADS)

    Moir, R. W.

    1986-12-01

    A magnetic fusion reactor can produce 10.8 kg of tritium at a fusion power of only 400 MW an order of magnitude lower power than that of a fission production reactor. Alternatively, the same fusion reactor can produce 995 kg of plutonium. Either a tokamak or a tandem mirror production plant can be used for this purpose; the cost is estimated at about 1.4 billion (1982 dollars) in either case. (The direct costs are estimated at 1.1 billion.) The production cost is calculated to be 22,000/g for tritium and 260/g for plutonium of quite high purity (1%240Pu). Because of the lack of demonstrated technology, such a plant could not be constructed today without significant risk. However, good progress is being made in fusion technology and, although success in magnetic fusion science and engineering is hard to predict with assurance, it seems possible that the physics basis and much of the needed technology could be demonstrated in facilities now under construction. Most of the remaining technology could be demonstrated in the early 1990s in a fusion test reactor of a few tens of megawatts. If the Magnetic Fusion Energy Program constructs a fusion test reactor of approximately 400 MW of fusion power as a next step in fusion power development, such a facility could be used later as a production reactor in a spinoff application. A construction decision in the late 1980s could result in an operating production reactor in the late 1990s. A magnetic fusion production reactor (MFPR) has four potential advantages over a fission production reactor: (1) no fissile material input is needed; (2) no fissioning exists in the tritium mode and very low fissioning exists in the plutonium mode thus avoiding the meltdown hazard; (3) the cost will probably be lower because of the smaller thermal power required; (4) and no reprocessing plant is needed in the tritium mode. The MFPR also has two disadvantages: (1) it will be more costly to operate because it consumes rather than sells electricity, and (2) there is a risk of not meeting the design goals.

  15. Moving bed reactor for solar thermochemical fuel production

    SciTech Connect

    Ermanoski, Ivan

    2013-04-16

    Reactors and methods for solar thermochemical reactions are disclosed. Embodiments of reactors include at least two distinct reactor chambers between which there is at least a pressure differential. In embodiments, reactive particles are exchanged between chambers during a reaction cycle to thermally reduce the particles at first conditions and oxidize the particles at second conditions to produce chemical work from heat. In embodiments, chambers of a reactor are coupled to a heat exchanger to pre-heat the reactive particles prior to direct exposure to thermal energy with heat transferred from reduced reactive particles as the particles are oppositely conveyed between the thermal reduction chamber and the fuel production chamber. In an embodiment, particle conveyance is in part provided by an elevator which may further function as a heat exchanger.

  16. Improving Jet Reactor Configuration for Production of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Povitsky, Alex

    2000-01-01

    The jet mixing reactor has been proposed for the industrial production of fullerene carbon nanotubes. Here we study the flowfield of this reactor using the SIMPLER algorithm. Hot peripheral jets are used to enhance heating of the central jet by mixing with the ambiance of reactor. Numerous configurations of peripheral jets with various number of jets, distance between nozzles, angles between the central jet and a peripheral jets, and twisted configuration of nozzles are considered. Unlike the previous studies of jet mixing, the optimal configuration of peripheral jets produces strong non-uniformity of the central jet in a cross-section. The geometrical shape of reactor is designed to obtain a uniform temperature of a catalyst.

  17. An immobilized cell reactor with simultaneous product separation. II. Experimental reactor performance.

    PubMed

    Dale, M C; Okos, M R; Wankat, P C

    1985-07-01

    The simultaneous separation of volatile fermentation products from product-inhibited fermentations can greatly increase the productivity of a bioreactor by reducing the product concentration in the bioreactor, as well as concentrating the product in an output stream free of cells, substrate, or other feed impurities. The Immobilized Cell Reactor-Separator (ICRS) consists of two column reactors: a cocurrent gas-liquid "enricher" followed by a countercurrent "stripper" The columns are four-phase tubular reactors consisting of (1) an inert gas phase, (2) the liquid fermentation broth, (3) the solid column internal packing, and (4) the immobilized biological catalyst or cells. The application of the ICRS to the ethanol-from-whey-lactose fermentation system has been investigated. Operation in the liquid continuous or bubble flow regime allows a high liquid holdup in the reactor and consequent long and controllable liquid residence time but results in a high gas phase pressure drop over the length of the reactor and low gas flow rates. Operation in the gas continuous regime gives high gas flow rates and low pressure drop but also results in short liquid residence time and incomplete column wetting at low liquid loading rates using conventional gas-liquid column packings. Using cells absorbed to conventional ceramic column packing (0.25-in. Intalox saddles), it was found that a good reaction could be obtained in the liquid continuous mode, but little separation, while in the gas continuous mode there was little reaction but good separation. Using cells sorbed to an absorbant matrix allowed operation in the gas continuous regime with a liquid holdup of up to 30% of the total reactor volume. Good reaction rates and product separation were obtained using this matrix. High reaction rates were obtained due to high density cell loading in the reactor. A dry cell density of up to 92 g/L reactor was obtained in the enricher. The enricher ethanol productivity ranged from 50 to 160 g/L h while the stripper productivity varied from 0 to 32 g/L h at different feed rates and concentrations. A separation efficiency of as high as 98% was obtained from the system. PMID:18553763

  18. Syngas production via methane steam reforming with oxygen: plasma reactors versus chemical reactors

    NASA Astrophysics Data System (ADS)

    Cormier, Jean Marie; Rusu, Iulian

    2001-09-01

    Steam reforming with oxygen (SRO) is a combination of non-catalytic partial oxidation and steam reforming of methane, industrially used for syngas production. There are several models of the chemical reactors used for this purpose but in the last decade a new direction has developed - plasma devices. The aim of the present paper is to make a comparative analysis between the autothermal reformers, including their improved variants, and the plasma reactors. The study is conceived in terms of advantages and disadvantages coming from the exploitation parameters, methane conversion, selectivity, energy efficiency and investment costs. Although SRO by means of chemical reactors may be the most efficient, plasma reactors represent an incisive approach by their simplicity, compactness and low price.

  19. Economics of power plant district and process heating in Richland, Washington

    SciTech Connect

    Fassbender, L.L.; Bloomster, C.H.

    1981-04-01

    The economic feasibility of utilizing hot water from nuclear reactors to provide district heating for private residences in Richland, Washington, and space and process heating for nearby offices, part of the Hanford Reservation, and the Lamb-Weston potato processing plant is assessed. Specifically, the practicality of using hot water from the Washington Public Power Supply System's WNP-1 reactor, which is currently under construction on the Hanford Reservation, just north of the City of Richland is established. World-wide experience with district heating systems and the advantages of using these systems are described. The GEOCITY computer model used to calculate district heating costs is described and the assumptions upon which the costs are based are presented. District heating costs for the city of Richland, process heating costs for the Lamb-Weston potato processing plant, district heating costs for the Horn Rapids triangle area, and process heating costs for the 300 and 3000 areas are discussed. An economic analysis is discussed and institutional restraints are summarized. (MCW)

  20. Thermal reactor. [liquid silicon production from silane gas

    NASA Technical Reports Server (NTRS)

    Levin, H.; Ford, L. B. (Inventor)

    1982-01-01

    A thermal reactor apparatus and method of pyrolyticaly decomposing silane gas into liquid silicon product and hydrogen by-product gas is disclosed. The thermal reactor has a reaction chamber which is heated well above the decomposition temperature of silane. An injector probe introduces the silane gas tangentially into the reaction chamber to form a first, outer, forwardly moving vortex containing the liquid silicon product and a second, inner, rewardly moving vortex containing the by-product hydrogen gas. The liquid silicon in the first outer vortex deposits onto the interior walls of the reaction chamber to form an equilibrium skull layer which flows to the forward or bottom end of the reaction chamber where it is removed. The by-product hydrogen gas in the second inner vortex is removed from the top or rear of the reaction chamber by a vortex finder. The injector probe which introduces the silane gas into the reaction chamber is continually cooled by a cooling jacket.

  1. INEL advanced test reactor plutonium-238 production feasibility assessment

    SciTech Connect

    Schnitzler, B.G. )

    1993-01-10

    Results of a preliminary neutronics assessment indicate the feasibility of [sup 238]Pu production in the Idaho National Engineering Laboratory Advanced Test Reactor (ATR). Based on the results of this assessment, an annual production of 11.3 kg [sup 238]Pu can be achieved in the ATR. An annual loading of 102 kg [sup 237]Np is required for the particular target configuration and irradiation scenario examined. The [sup 236]Pu contaminant level is approximately 6 parts per million at zero cooling time. The product quality is about 90% [sup 238]Pu. Neptunium feedstock requirements, [sup 238]Pu production rates, or product purity can be optimized depending on their relative importances.

  2. Richland Environmental Restoration Project management action process document

    SciTech Connect

    1996-04-01

    A critical mission of the U.S. Department of Energy (DOE) is the planning, implementation, and completion of environmental restoration programs at DOE facilities. An integral part of this mission involves the safe and cost-effective environmental restoration of the Hanford Site. For over 40 years the Hanford Site supported United States national defense programs, largely through the production of nuclear materials. One legacy of historical Hanford Site operations is a significant waste inventory of radioactive and/or regulated chemical materials. Releases of these materials have, in some cases, contaminated the Hanford Site environment. The DOE Richland Operations Office (RL) is responsible for protecting human health and the environment from potential Hanford Site environmental hazards by identifying, assessing, and mitigating risks posed by contaminated sites.

  3. NOVEL REACTOR FOR THE PRODUCTION OF SYNTHESIS GAS

    SciTech Connect

    Vasilis Papavassiliou; Leo Bonnell; Dion Vlachos

    2004-12-01

    Praxair investigated an advanced technology for producing synthesis gas from natural gas and oxygen This production process combined the use of a short-reaction time catalyst with Praxair's gas mixing technology to provide a novel reactor system. The program achieved all of the milestones contained in the development plan for Phase I. We were able to develop a reactor configuration that was able to operate at high pressures (up to 19atm). This new reactor technology was used as the basis for a new process for the conversion of natural gas to liquid products (Gas to Liquids or GTL). Economic analysis indicated that the new process could provide a 8-10% cost advantage over conventional technology. The economic prediction although favorable was not encouraging enough for a high risk program like this. Praxair decided to terminate development.

  4. Life extension approach to the reactor vessel of a nuclear production reactor: Revision 1

    SciTech Connect

    Sindelar, R.L.; Awadalla, N.G.; Baumann, N.P.; Mehta, H.S.

    1989-01-01

    The nuclear materials production reactors at the Savannah River Plant have been in service for over 35 years. All the primary components of the reactor system are readily accessible for repair or replacement as needed except for the reactor vessel and thermal shields. The reactor vessel of a Savannah River Plant reactor is a cylindrical tank approximately 16 feet in diameter and 14 feet high and is not pressurized except for a 5 psig helium blanket gas in addition to the hydrostatic head of the heavy water (D/sub 2/O) moderator. The vessels are made of American Iron and Steel Institute Type 304 stainless steel fabricated into cylindrical shells with four to six wrought plates per vessel, 1.27 cm (0.5-inches) thick. The shells were made up in flat in two half-sections for later rolling and welding. The vessel bottom section containing the moderator effluent nozzles was welded to the shell in a T-joint configuration. All joining was performed with multipass Metal Inert Gas (MIG) welding. The service life assessment of the reactor vessel addresses the corrosive effects of the D/sub 2/O moderator and the degradation of the vessel material properties through exposure of the vessel to neutron irradiation. Potential degradation mechanisms include radiation embrittlement, Intergranular Stress Corrosion Cracking; and Irradiation-Assisted Stress Corrosion Cracking. 15 refs., 11 figs.

  5. A microBio reactor for hydrogen production.

    SciTech Connect

    Volponi, Joanne V.; Walker, Andrew William

    2003-12-01

    The purpose of this work was to explore the potential of developing a microfluidic reactor capable of enzymatically converting glucose and other carbohydrates to hydrogen. This aggressive project was motivated by work in enzymatic hydrogen production done by Woodward et al. at OWL. The work reported here demonstrated that hydrogen could be produced from the enzymatic oxidation of glucose. Attempts at immobilizing the enzymes resulted in reduced hydrogen production rates, probably due to buffer compatibility issues. A novel in-line sensor was also developed to monitor hydrogen production in real time at levels below 1 ppm. Finally, a theoretical design for the microfluidic reactor was developed but never produced due to the low production rates of hydrogen from the immobilized enzymes. However, this work demonstrated the potential of mimicking biological systems to create energy on the microscale.

  6. A proposed standard on medical isotope production in fission reactors

    SciTech Connect

    Schenter, R. E.; Brown, G. J.; Holden, C. S.

    2006-07-01

    Authors Robert E. Sehenter, Garry Brown and Charles S. Holden argue that a Standard for 'Medical Isotope Production' is needed. Medical isotopes are becoming major components of application for the diagnosis and treatment of all the major diseases including all forms of cancer, heart disease, arthritis, Alzheimer's, among others. Current nuclear data to perform calculations is incomplete, dated or imprecise or otherwise flawed for many isotopes that could have significant applications in medicine. Improved data files will assist computational analyses to design means and methods for improved isotope production techniques in the fission reactor systems. Initial focus of the Standard is expected to be on neutron cross section and branching data for both fast and thermal reactor systems. Evaluated and reviewed tables giving thermal capture cross sections and resonance integrals for the major target and product medical isotopes would be the expected 'first start' for the 'Standard Working Group'. (authors)

  7. Production of long-lived hafnium isomers in reactor irradiations

    NASA Astrophysics Data System (ADS)

    Karamian, S. A.; Carroll, J. J.; Adam, J.; Kulagin, E. N.; Shabalin, E. P.

    2006-06-01

    Experiments on production of long-lived Hf178m isomer in reactor irradiations are described. Properties of this nuclide are promising for its potential application as a relatively safe power source characterized by high density of accumulated energy. Metal natHf samples were activated in the Dubna IBR-2 reactor at positions corresponding to different neutron fluxes. Samples were bare or shielded by Cd and B 4C layers. The gamma activity of the samples was analyzed with Ge gamma spectrometers during a two-year period following their irradiation. In the presence of dominant activation products 175Hf and 181Hf, the high-spin isomers Hf178m and Hf179m were also detected despite relatively low levels. The isomer-to-ground state ratios and cross-sections were determined from the measured yields. For Hf178m, the cross-section for burnup (destruction) by neutron capture after its production was also estimated, clarifying the results from earlier experiments. In the context of suggestions for use of Hf178m for applications, the results confirm that large-scale production of this isomer by reactor irradiations is not feasible. In contrast, the efficiency of production of Hf179m is much higher and an amount of about 10 16 atoms may be produced in standard reactor irradiations. For Hf178m, more productive methods are known, in particular fast neutron irradiations at E n ≥ 14 MeV and spallation reactions at intermediate energies. Neutron cross-sections for isomers may also be significant in astrophysics.

  8. A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atroshenko; Francis Lau; Mike Roberts

    2005-07-29

    Gas Technology Institute is developing a novel concept of membrane reactor coupled with a gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates. Hydrogen permeation data for several perovskite membranes BCN (BaCe{sub 0.9}Nd{sub 0.1}O{sub 3-x}), SCE (SrCe{sub 0.9}Eu{sub 0.1}O{sub 3}) and SCTm (SrCe{sub 0.95}Tm{sub 0.05}O{sub 3}) have been successfully obtained for temperatures between 800 and 950 C and pressures from 1 to 12 bar in this project. However, it is known that the cerate-based perovskite materials can react with CO{sub 2}. Therefore, the stability issue of the proton conducting perovskite materials under CO{sub 2} or H{sub 2}S environments was examined. Tests were conducted in the Thermo Gravimetric Analyzer (TGA) unit for powder and disk forms of BCN and SCE. Perovskite materials doped with zirconium (Zr) are known to be resistant to CO{sub 2}. The results from the evaluation of the chemical stability for the Zr doped perovskite membranes are presented. During this reporting period, flowsheet simulation was also performed to calculate material and energy balance based on several hydrogen production processes from coal using high temperature membrane reactor (1000 C), low temperature membrane reactor (250 C), or conventional technologies. The results show that the coal to hydrogen process employing both the high temperature and the low temperature membrane reactors can increase the hydrogen production efficiency (cold gas efficiency) by more than 50% compared to the conventional process. Using either high temperature or low temperature membrane reactor process also results in an increase of the cold gas efficiencies as well as the thermal efficiencies of the overall process.

  9. Mass production of magnetic nickel nanoparticle in thermal plasma reactor

    SciTech Connect

    Kanhe, Nilesh S.; Nawale, Ashok B.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2014-04-24

    We report the mass production of Ni metal nanoparticles using dc transferred arc thermal plasma reactor by homogeneous gas phase condensation process. To increase the evaporation rate and purity of Ni nanoparticles small amount of hydrogen added along with argon in the plasma. Crystal structure analysis was done by using X-ray diffraction technique. The morphology of as synthesized nanoparticles was carried out using FESEM images. The magnetic properties were measured by using vibrating sample magnetometer at room temperature.

  10. Hydrogen Production via a Commercially Ready Inorganic membrane Reactor

    SciTech Connect

    Paul K.T. Liu

    2005-08-23

    Single stage low-temperature-shift water-gas-shift (WGS-LTS) via a membrane reactor (MR) process was studied through both mathematical simulation and experimental verification in this quarter. Our proposed MR yields a reactor size that is 10 to >55% smaller than the comparable conventional reactor for a CO conversion of 80 to 90%. In addition, the CO contaminant level in the hydrogen produced via MR ranges from 1,000 to 4,000 ppm vs 40,000 to >70,000 ppm via the conventional reactor. The advantages of the reduced WGS reactor size and the reduced CO contaminant level provide an excellent opportunity for intensification of the hydrogen production process by the proposed MR. To prepare for the field test planned in Yr III, a significant number (i.e., 98) of full-scale membrane tubes have been produced with an on-spec ratio of >76% during this first production trial. In addition, an innovative full-scale membrane module has been designed, which can potentially deliver >20 to 30 m{sup 2}/module making it suitable for large-scale applications, such as power generation. Finally, we have verified our membrane performance and stability in a refinery pilot testing facility on a hydrocracker purge gas. No change in membrane performance was noted over the >100 hrs of testing conducted in the presence of >30% H{sub 2}S, >5,000 ppm NH{sub 3} (estimated), and heavy hydrocarbons on the order of 25%. The high stability of these membranes opens the door for the use of our membrane in the WGS environment with significantly reduced pretreatment burden.

  11. Corrosion-product release in light water reactors

    SciTech Connect

    Lister, D.; Davidson, R.D. . Chalk River Nuclear Labs.)

    1989-09-01

    This is the final report of a research program aimed at measuring and studying the release of corrosion products from typical PWR and BWR materials to reactor coolant. The program has provided measurements of release from stainless steel, steam generator alloys and hard-facing material (Stellite) to PWR coolant under several chemistry conditions. Kinetic expressions for cumulative release as a function of time have been developed. Corrosion measurements in- and out-reactor have indicated little effect of reactor radiation on corrosion of these materials. Detailed surface analysis has characterized the formation of oxide films in PWR coolant, and has led to suggestions of mechanisms of release. The mechanisms have been made the basis of a system model which has been used to evaluate the effects of various system parameters on the concentration of dissolved cobalt in the coolant--i.e., on the source term for activity transport. The understanding of film formation and release have led to a proposed method of preconditioning PWRs to reduce substantially radiation fields during subsequent operation. Correlations for elemental release from stainless steel and Stellite under BWR conditions have also been derived. They indicate that cobalt-based alloys in BWR reactor circuits are the major source of corrosion-released cobalt. The effects of zinc on the growth of oxide films on carbon steel, Inconel-600 and Stellite-6 are also described. 39 refs., 38 figs., 12 tabs.

  12. Recharge to the North Richland well field

    SciTech Connect

    Law, A.G.

    1989-07-01

    The investigation was based on a preliminary ground-water flow model of the 1100 Area. Because few local data were available for this effort, an existing regional ground-water flow model of the Hanford Site was applied, which is based on the Variable Thickness Transient (VTT) ground-water flow code (Kipp et al., 1976). A submodel of the Hanford Site model was developed based on the VTT code. An independent model consisting of a simple representation of the local conditions in the vicinity of the North Richland well field was also used in the investigation. This model, based on the MODFLOW code (McDonald and Harbaugh, 1984), was used in a series of transient simulations to examine dynamic aspects of the well field/recharge basin. Results from this simple model also provide an independent, qualitative check of results produced with the 1100 Area model based on the VTT code. This report summarizes the 1100 Area modeling investigation, including the approach used to generate results for the regional and 1100 Area VTT models, the approach used in the transient MODFLOW model, results from some initial steady-state and transient simulations with the submodel and the MODFLOW models, and resulting conclusions and recommendations. Because local data were lacking to develop and calibrate the models, the investigation described in this report can best be described as a ''sensitivity analysis'' of ground-water flow in the 1100 Area. 4 refs., 10 figs., 2 tabs.

  13. Lead test assembly irradiation and analysis Watts Bar Nuclear Plant, Tennessee and Hanford Site, Richland, Washington

    SciTech Connect

    1997-07-01

    The U.S. Department of Energy (DOE) needs to confirm the viability of using a commercial light water reactor (CLWR) as a potential source for maintaining the nation`s supply of tritium. The Proposed Action discussed in this environmental assessment is a limited scale confirmatory test that would provide DOE with information needed to assess that option. This document contains the environmental assessment results for the Lead test assembly irradiation and analysis for the Watts Bar Nuclear Plant, Tennessee, and the Hanford Site in Richland, Washington.

  14. Richland Environmental Restoration Project management action process document

    SciTech Connect

    1996-04-01

    This document is the prescribed means for providing direct input to the US Department of Energy Headquarters regarding the status, accomplishments, strategy, and issues of the Richland Environmental Restoration Project. The project mission, organizational interfaces, and operational history of the Hanford Site are provided. Remediation strategies are analyzed in detail. The document includes a status of Richland Environmental Restoration project activities and accomplishments, and it presents current cost summaries, schedules, and technical baselines.

  15. ``Sleeping reactor`` irradiations: Shutdown reactor determination of short-lived activation products

    SciTech Connect

    Jerde, E.A.; Glasgow, D.C.

    1998-09-01

    At the High-Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory, the principal irradiation system has a thermal neutron flux ({phi}) of {approximately} 4 {times} 10{sup 14} n/cm{sup 2} {center_dot} s, permitting the detection of elements via irradiation of 60 s or less. Irradiations of 6 or 7 s are acceptable for detection of elements with half-lives of as little as 30 min. However, important elements such as Al, Mg, Ti, and V have half-lives of only a few minutes. At HFIR, these can be determined with irradiation times of {approximately} 6 s, but the requirement of immediate counting leads to increased exposure to the high activity produced by irradiation in the high flux. In addition, pneumatic system timing uncertainties (about {+-} 0.5 s) make irradiations of < 6 s less reliable. Therefore, the determination of these ultra-short-lived species in mixed matrices has not generally been made at HFIR. The authors have found that very short lived activation products can be produced easily during the period after reactor shutdown (SCRAM), but prior to the removal of spent fuel elements. During this 24- to 36-h period (dubbed the ``sleeping reactor``), neutrons are produced in the beryllium reflector by the reaction {sup 9}Be({gamma},n){sup 8}Be, the gamma rays principally originating in the spent fuel. Upon reactor SCRAM, the flux drops to {approximately} 1 {times} 10{sup 10} n/cm{sup 2} {center_dot} s within 1 h. By the time the fuel elements are removed, the flux has dropped to {approximately} 6 {times} 10{sup 8}. Such fluxes are ideal for the determination of short-lived elements such as Al, Ti, Mg, and V. An important feature of the sleeping reactor is a flux that is not constant.

  16. Preconceptual design of the new production reactor circulator test facility

    SciTech Connect

    Thurston, G.

    1990-06-01

    This report presents the results of a study of a new circulator test facility for the New Production Reactor Modular High-Temperature Gas-Cooled Reactor. The report addresses the preconceptual design of a stand-alone test facility with all the required equipment to test the Main Circulator/shutoff valve and Shutdown Cooling Circulator/shutoff valve. Each type of circulator will be tested in its own full flow, full power helium test loop. Testing will cover the entire operating range of each unit. The loop will include a test vessel, in which the circulator/valve will be mounted, and external piping. The external flow piping will include a throttle valve, flowmeter, and heat exchanger. Subsystems will include helium handling, helium purification, and cooling water. A computer-based data acquisition and control system will be provided. The estimated costs for the design and construction of this facility are included. 2 refs., 15 figs.

  17. Production of transplutonium elements in the high flux isotope reactor

    SciTech Connect

    Bigelow, J.E.; Corbett, B.L.; King, L.J.; McGuire, S.C.; Sims, T.M.

    1981-01-01

    The techniques described here have been demonstrated to predict the contents of transplutonium element production targets, at least for isotopes of mass 253 or less. The HFIR irradiation model is a workhorse for planning the TRU processing campaigns, for certifying the heat evolution rate of targets prior to insertion in the reactor, for predicting future production capabilities over a multi-year period, and for making optimization studies. Practical considerations, however, may limit the range of available options so that optimum operation is not always achievable. We do intend, however, to keep fine-tuning the constants which define the cross sections as time permits. We need to do more work on optimizing the production of /sup 250/Cm, /sup 254/Es, /sup 255/Es, and ultimately /sup 257/Fm, since researchers are interested in obtaining larger quantities of these rare and difficult-to-produce nuclides. 7 figures, 2 tables.

  18. MANHATTAN PROJECT B REACTOR HANFORD WASHINGTON [HANFORD'S HISTORIC B REACTOR (12-PAGE BOOKLET)

    SciTech Connect

    GERBER MS

    2009-04-28

    The Hanford Site began as part of the United States Manhattan Project to research, test and build atomic weapons during World War II. The original 670-square mile Hanford Site, then known as the Hanford Engineer Works, was the last of three top-secret sites constructed in order to produce enriched uranium and plutonium for the world's first nuclear weapons. B Reactor, located about 45 miles northwest of Richland, Washington, is the world's first full-scale nuclear reactor. Not only was B Reactor a first-of-a-kind engineering structure, it was built and fully functional in just 11 months. Eventually, the shoreline of the Columbia River in southeastern Washington State held nine nuclear reactors at the height of Hanford's nuclear defense production during the Cold War era. The B Reactor was shut down in 1968. During the 1980's, the U.S. Department of Energy began removing B Reactor's support facilities. The reactor building, the river pumphouse and the reactor stack are the only facilities that remain. Today, the U.S. Department of Energy (DOE) Richland Operations Office offers escorted public access to B Reactor along a designated tour route. The National Park Service (NPS) is studying preservation and interpretation options for sites associated with the Manhattan Project. A draft is expected in summer 2009. A final report will recommend whether the B Reactor, along with other Manhattan Project facilities, should be preserved, and if so, what roles the DOE, the NPS and community partners will play in preservation and public education. In August 2008, the DOE announced plans to open B Reactor for additional public tours. Potential hazards still exist within the building. However, the approved tour route is safe for visitors and workers. DOE may open additional areas once it can assure public safety by mitigating hazards.

  19. Fusion-based hydrogen production reactor and its material selection

    NASA Astrophysics Data System (ADS)

    Wu, Y.; FDS Team

    2009-04-01

    The fusion-based hydrogen production reactor (named FDS-III), one of the series of fusion system design concepts developed in China, is designated to exploit the fusion energy advanced application for the production of hydrogen. In this paper, a conceptual design of FDS-III is presented, including the design of plasma core, high temperature blanket, divertor and related auxiliary systems. In particular, an innovative high temperature liquid blanket (named HTL) concept with the multi-layer flow channel inserts in the liquid metal LiPb channels and the reduced activation ferritic/martensitic steel as the structural material is proposed to achieve LiPb outlet temperature of about 1000 °C for high efficient production of hydrogen. The preliminary performance analyzes have demonstrated the feasibility of the design. Based on the design and analyzes, a selection of the materials for the FDS-III reactor and related auxiliary systems has been performed with indication of further R&D needs.

  20. Application of the MACCS code to DOE production reactor operation

    SciTech Connect

    O'Kula, K.R.; East, J.M. )

    1991-01-01

    A three-level probabilistic risk assessment (PRA) of the special materials production reactor operation at the US Department of Energy's (DOE's) Savannah River site (SRS) has been completed. The goals of this analysis were to: (1) analyze existing margins of safety provided by the heavy water reactor (HWR) design challenged by postulated severe accidents; (2) compare measures of risk to the general public and on-site workers to guideline values, as well as to those posed by commercial reactor operation; and (3) develop the methodology and data base necessary to determine the equipment, human actions, and engineering systems that contribute significantly to ensuring overall plant safety. In particular, the third point provides the most tangible benefit of a PRA since the process yields a prioritized approach to increasing safety through design and operating practices. This paper describes key aspects of the consequence analysis portion of the SRS PRA: Given the radiological releases quantified through the level-2 PRA analysis, the consequences to the off-site general public and to the on-site SRS workforce are calculated. This analysis, the third level of the PRA, is conducted primarily with the MACCS 1.5 code. The level-3 PRA yields a probabilistic assessment of health and economic effects based on meteorological conditions sampled from site-specific data.

  1. Westinghouse independent safety review of Savannah River production reactors

    SciTech Connect

    Leggett, W.D.; McShane, W.J. ); Liparulo, N.J.; McAdoo, J.D.; Strawbridge, L.E. . Nuclear and Advanced Technology Div.); Toto, G. . Nuclear Services Div.); Fauske, H.K. ); Call, D.W. (Westinghouse Savannah R

    1989-04-01

    Westinghouse Electric Corporation has performed a safety assessment of the Savannah River production reactors (K,L, and P) as requested by the US Department of Energy. This assessment was performed between November 1, 1988, and April 1, 1989, under the transition contract for the Westinghouse Savannah River Company's preparations to succeed E.I. du Pont de Nemours Company as the US Department of Energy contractor for the Savannah River Project. The reviewers were drawn from several Westinghouse nuclear energy organizations, embody a combination of commercial and government reactor experience, and have backgrounds covering the range of technologies relevant to assessing nuclear safety. The report presents the rationale from which the overall judgment was drawn and the basis for the committee's opinion on the phased restart strategy proposed by E.I. du Pont de Nemours Company, Westinghouse, and the US Department of Energy-Savannah River. The committee concluded that it could recommend restart of one reactor at partial power upon completion of a list of recommended upgrades both to systems and their supporting analyses and after demonstration that the organization had assimilated the massive changes it will have undergone.

  2. Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis: II. Quantification of inhibition and suitability of membrane reactors.

    PubMed

    Andrić, Pavle; Meyer, Anne S; Jensen, Peter A; Dam-Johansen, Kim

    2010-01-01

    Product inhibition of cellulolytic enzymes affects the efficiency of the biocatalytic conversion of lignocellulosic biomass to ethanol and other valuable products. New strategies that focus on reactor designs encompassing product removal, notably glucose removal, during enzymatic cellulose conversion are required for alleviation of glucose product inhibition. Supported by numerous calculations this review assesses the quantitative aspects of glucose product inhibition on enzyme-catalyzed cellulose degradation rates. The significance of glucose product inhibition on dimensioning of different ideal reactor types, i.e. batch, continuous stirred, and plug-flow, is illustrated quantitatively by modeling different extents of cellulose conversion at different reaction conditions. The main operational challenges of membrane reactors for lignocellulose conversion are highlighted. Key membrane reactor features, including system set-up, dilution rate, glucose output profile, and the problem of cellobiose are examined to illustrate the quantitative significance of the glucose product inhibition and the total glucose concentration on the cellulolytic conversion rate. Comprehensive overviews of the available literature data for glucose removal by membranes and for cellulose enzyme stability in membrane reactors are given. The treatise clearly shows that membrane reactors allowing continuous, complete, glucose removal during enzymatic cellulose hydrolysis, can provide for both higher cellulose hydrolysis rates and higher enzyme usage efficiency (kg(product)/kg(enzyme)). Current membrane reactor designs are however not feasible for large scale operations. The report emphasizes that the industrial realization of cellulosic ethanol requires more focus on the operational feasibility within the different hydrolysis reactor designs, notably for membrane reactors, to achieve efficient enzyme-catalyzed cellulose degradation. PMID:20172020

  3. A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atroshenko; Francis Lau; Mike Roberts

    2004-07-29

    Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates. To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit has been constructed in this project. During this reporting period, the unit has been fully commissioned and is operational. The unit is capable of operating at temperatures up to 1100 C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. A double-seal technique has been developed and tested successfully to achieve leak-tight seal for the membranes. Initial data for a commercial Palladium-Gold membrane were obtained at temperatures to 450 C and pressures to 13 atm. Tests for the perovskite membranes are being performed and the results will be reported in the next quarter. A membrane gasification reactor model was developed to consider the H{sub 2} permeability of the membrane, the kinetics and the equilibriums of the gas phase reactions in the gasifier, the operating conditions and the configurations of the membrane reactor. The results show that the hydrogen production efficiency using the novel membrane gasification reactor concept can be increased by about 50% versus the conventional gasification process. This confirms the previous evaluation results from the thermodynamic equilibrium calculation. A rigorous model for hydrogen permeation through mixed proton-electron conducting ceramic membranes was also developed based on non-equilibrium thermodynamics. The results from the simulation work confirm that the hydrogen flux increases with increasing partial pressure of hydrogen. The presence of steam in the permeate side can have a small negative effect on the hydrogen flux, in the order of 10%. When the steam partial pressure is greater than 1 atm, the hydrogen flux becomes independent of the steam pressure.

  4. A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atroshenko; Mike Roberts; Francis Lau

    2004-04-26

    Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates. To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit will be constructed in this project. During this reporting period, the mechanical construction of the permeation unit was completed. Commissioning and shake down tests are being conducted. The unit is capable of operation at temperatures up to 1100 C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. The membranes to be tested will be in disc form with a diameter of about 3 cm. Operation at these high temperatures and high hydrogen partial pressures will demonstrate commercially relevant hydrogen flux, 10{approx}50 cc/min/cm{sup 2}, from the membranes made of the perovskite type of ceramic material. Preliminary modeling was also performed for a tubular membrane reactor within a gasifier to estimate the required membrane area for a given gasification condition. The modeling results will be used to support the conceptual design of the membrane reactor.

  5. Biohydrogen production from tequila vinasses using a fixed bed reactor.

    PubMed

    Buitrón, Germán; Prato-Garcia, Dorian; Zhang, Axue

    2014-01-01

    In Mexico, the industrial production of tequila leads to the discharge of more than 31.2 million of m(3) of vinasse, which causes serious environmental issues because of its acidity, high organic load and the presence of recalcitrant compounds. The aim of this research was to study the feasibility of a fixed bed reactor for the production of biohydrogen by using tequila vinasse as substrate. The experiments were carried out in a continuous mode under mesophilic and acidic conditions. The maximum hydrogen yield and hydrogen production rate were 1.3 mol H2 mol/mol glucose and 72 ± 9 mL H2/(Lreactor h), respectively. Biogas consisted of carbon dioxide (36%) and hydrogen (64%); moreover methane was not observed. The electron-equivalent mass balance fitted satisfactorily (sink of electrons from 0.8 to 7.6%). For vinasses, hydrogen production accounted for 10.9% of the total available electron-equivalents. In the liquid phase, the principal metabolites identified were acetic, butyric and iso-butyric acids, which indicated a butyrate-acetate type fermentation. Tequila vinasses did not result in potential inhibition of the fermentative process. Considering the process as a water treatment system, only 20% of the original carbon was removed (as carbon dioxide and biomass) when the tequila vinasses are used. PMID:25521125

  6. A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atroshenko; Francis Lau; Mike Roberts

    2004-01-22

    Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying the potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates. To evaluate the candidate membrane performance under the gasification conditions, a high temperature/high pressure hydrogen permeation unit will be constructed in this project. During this reporting period, the design of this unit was completed. The unit will be capable of operating at temperatures up to 1100 C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. The membranes to be tested will be in disc form with a diameter of about 3 cm. By operating at higher temperatures and higher hydrogen partial pressures, we expect to demonstrate commercially relevant hydrogen flux, 10 {approx} 50 cc/min/cm{sup 2}, from the membranes made of the perovskite type of ceramic material. The construction of the unit is planned to be completed by the end of the next reporting period.

  7. Bio-hydrogen production from molasses by anaerobic fermentation in continuous stirred tank reactor

    NASA Astrophysics Data System (ADS)

    Han, Wei; Li, Yong-feng; Chen, Hong; Deng, Jie-xuan; Yang, Chuan-ping

    2010-11-01

    A study of bio-hydrogen production was performed in a continuous flow anaerobic fermentation reactor (with an available volume of 5.4 L). The continuous stirred tank reactor (CSTR) for bio-hydrogen production was operated under the organic loading rates (OLR) of 8-32 kg COD/m3 reactor/d (COD: chemical oxygen demand) with molasses as the substrate. The maximum hydrogen production yield of 8.19 L/d was obtained in the reactor with the OLR increased from 8 kg COD/m3 reactor/d to 24 kg COD/m3 d. However, the hydrogen production and volatile fatty acids (VFAs) drastically decreased at an OLR of 32 kg COD/m3 reactor/d. Ethanoi, acetic, butyric and propionic were the main liquid fermentation products with the percentages of 31%, 24%, 20% and 18%, which formed the mixed-type fermentation.

  8. Design and characterization of a temporal analysis of products reactor.

    PubMed

    Leppelt, R; Hansgen, D; Widmann, D; Häring, T; Bräth, G; Behm, R J

    2007-10-01

    We describe an improved temporal analysis of products (TAP) reactor design whose main new features in comparison to the recent TAP-2 design of Gleaves et al. [Appl. Catal. A 160, 55 (1997)] are the use of a turbomolecular pump, piezoelectrically driven pulse valves, and a newly designed, differentially pumped gate valve. The gate valve allows fast and simple changes between high pressure operation, in which in situ catalyst treatment can be performed, and the analytic mode with a direct line-of-sight connection to the analysis chamber and the mass spectrometer. The heating system and pulse valves are located outside the vacuum chamber, resulting in a system that is easy to operate and modify. The high stability and reproducibility of the pulse intensity allows for direct, quantitative evaluation of single-pulse and multipulse experiments. The performance of the system is demonstrated using the CO oxidation over a Au/TiO(2) catalyst as test reaction. PMID:17979438

  9. Reactor production of sup 252 Cf and transcurium isotopes

    SciTech Connect

    Alexander, C.W.; Halperin, J.; Walker, R.L.; Bigelow, J.E.

    1990-01-01

    Berkelium, californium, einsteinium, and fermium are currently produced in the High Flux Isotope Reactor (HFIR) and recovered in the Radiochemical Engineering Development Center (REDC) at the Oak Ridge National Laboratory (ORNL). All the isotopes are used for research. In addition, {sup 252}Cf, {sup 253}Es, and {sup 255}Fm have been considered or are used for industrial or medical applications. ORNL is the sole producer of these transcurium isotopes in the western world. A wide range of actinide samples were irradiated in special test assemblies at the Fast Flux Test Facility (FFTF) at Hanford, Washington. The purpose of the experiments was to evaluate the usefulness of the two-group flux model for transmutations in the special assemblies with an eventual goal of determining the feasibility of producing macro amounts of transcurium isotopes in the FFTF. Preliminary results from the production of {sup 254g}Es from {sup 252}Cf will be discussed. 14 refs., 5 tabs.

  10. A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atroshenko; Francis Lau; Mike Roberts

    2004-10-26

    Gas Technology Institute is developing a novel concept of membrane gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates. To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit has been constructed in this project. The unit is designed to operate at temperatures up to 1100 C and pressures to 60 atm for evaluation of ceramic membranes such as mixed ionic conducting membrane. The unit was fully commissioned and is operational. Several perovskite membranes based on the formulations of BCN (BaCe{sub 0.8}Nd{sub 0.2}O{sub 3-x}) and BCY (BaCe{sub 0.8}Y{sub 0.2}O{sub 3-x}) were prepared by GTI and tested in the new permeation unit. These membranes were fabricated by either uniaxial pressing or tape casting technique with thickness ranging from 0.2 mm to 0.7 mm. Hydrogen permeation data for the BCN perovskite membrane have been successfully obtained for temperatures between 800 and 950 C and pressures from 1 to 12 bar. The highest hydrogen flux was measured at 1.6 STPcc/min/cm{sup 2} at a hydrogen feed pressure of 12 bar and 950 C with a membrane thickness of 0.22 mm. A membrane gasification reactor model was developed to consider the H{sub 2} permeability of the membrane, the kinetics and the equilibriums of the gas phase reactions in the gasifier, the operating conditions and the configurations of the membrane reactor. The results show that the hydrogen production efficiency using the novel membrane gasification reactor concept can be increased by about 50% versus the conventional gasification process. This confirms the previous evaluation results from the thermodynamic equilibrium calculation. A rigorous model for hydrogen permeation through mixed proton-electron conducting ceramic membranes was also developed based on non-equilibrium thermodynamics. The hydrogen flux predicted from the modeling results are in line with the data from the experimental measurement. The simulation also shows that the presence of steam in the permeate side or the feed side of the membrane can have a small negative effect on the hydrogen flux, in the order of 10%.

  11. Gas Reactor Plant Analyzer and Simulator for Hydrogen Production

    Energy Science and Technology Software Center (ESTSC)

    2004-01-01

    This software is used to study and analyze various configurations of plant equipment for gas cooled nuclear reactor applications. The user of this software would likely be interested in optimizing the economic, safety, and operating performance of this type of reactor. The code provides the capability for the user through his input to configure networks of nuclear reactor components. The components available include turbine, compressor, heat exchanger, reactor core, coolers, bypass valves, and control systems.

  12. Uncertainties in the Anti-neutrino Production at Nuclear Reactors

    SciTech Connect

    Djurcic, Zelimir; Detwiler, Jason A.; Piepke, Andreas; Foster Jr., Vince R.; Miller, Lester; Gratta, Giorgio

    2008-08-06

    Anti-neutrino emission rates from nuclear reactors are determined from thermal power measurements and fission rate calculations. The uncertainties in these quantities for commercial power plants and their impact on the calculated interaction rates in {bar {nu}}{sub e} detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties, and their relevance to reactor {bar {nu}}{sub e} experiments.

  13. A Novel Membrane Reactor for Direct Hydrogen Production From Coal

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atrosphenko; Francis Lau; Mike Roberts

    2006-01-20

    Gas Technology Institute has developed a novel concept of a membrane reactor closely coupled with a coal gasifier for direct extraction of hydrogen from coal-derived syngas. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under the coal gasification conditions. The best performing membranes were selected for preliminary reactor design and cost estimate. The overall economics of hydrogen production from this new process was assessed and compared with conventional hydrogen production technologies from coal. Several proton-conducting perovskite membranes based on the formulations of BCN (BaCe{sub 0.8}Nd{sub 0.2}O{sub 3-x}), BCY (BaCe{sub 0.8}Y{sub 0.2}O{sub 3-x}), SCE (Eu-doped SrCeO{sub 3}) and SCTm (SrCe{sub 0.95}Tm{sub 0.05}O{sub 3}) were successfully tested in a new permeation unit at temperatures between 800 and 1040 C and pressures from 1 to 12 bars. The experimental data confirm that the hydrogen flux increases with increasing hydrogen partial pressure at the feed side. The highest hydrogen flux measured was 1.0 cc/min/cm{sup 2} (STP) for the SCTm membrane at 3 bars and 1040 C. The chemical stability of the perovskite membranes with respect to CO{sub 2} and H{sub 2}S can be improved by doping with Zr, as demonstrated from the TGA (Thermal Gravimetric Analysis) tests in this project. A conceptual design, using the measured hydrogen flux data and a modeling approach, for a 1000 tons-per-day (TPD) coal gasifier shows that a membrane module can be configured within a fluidized bed gasifier without a substantial increase of the gasifier dimensions. Flowsheet simulations show that the coal to hydrogen process employing the proposed membrane reactor concept can increase the hydrogen production efficiency by more than 50% compared to the conventional process. Preliminary economic analysis also shows a 30% cost reduction for the proposed membrane reactor process, assuming membrane materials meeting DOE's flux and cost target. Although this study shows that a membrane module can be configured within a fluidized bed gasifier, placing the membrane module outside the gasifier in a closely coupled way in terms of temperature and pressure can still offer the same performance advantage. This could also avoid the complicated fluid dynamics and heat transfer issues when the membrane module is installed inside the gasifier. Future work should be focused on improving the permeability and stability for the proton-conducting membranes, testing the membranes with real syngas from a gasifier and scaling up the membrane size.

  14. Study on membrane reactors for biodiesel production by phase behaviors of canola oil methanolysis in batch reactors.

    PubMed

    Cheng, Li-Hua; Yen, Shih-Yang; Su, Li-Sheng; Chen, Junghui

    2010-09-01

    In comparison with the general stirring batch reactor, the membrane reactor has been reported to have higher molar ratios of methanol to oil but ultralow catalyst concentration in the biodiesel production. In this research, the methanolysis of canola oil is conducted in a stirring batch reactor in the presence of NaOH as a catalyst. Based on the investigation of the effects of operating conditions, including methanol to oil molar ration, catalyst concentrations and temperatures, the time course of the reaction path for the reactant composition in the ternary phase diagram of oil-FAME-MeOH offers an effective way to understand the operation of membrane reactors in the biodiesel production. The results show that increasing the residence time of the whole reactant system within the two-phase zone is good for the separation operation through the membranes. PMID:20435472

  15. Maintenance Implementation Plan for the 100K Fuel Storage Basins and 100N Reactor

    SciTech Connect

    Turner, F.R.

    1992-06-01

    The 100N Reactor and 100K Fuel Storage Basins facilities are located in the northwest quadrant of the US Department of Energy, Richland Field Office (RL) Hanford Site adjacent to the Columbia River approximately 35 mi from the city of Richland Washington. The 100N Reactor is a graphite-moderated pressure tube, light watercooled reactor constructed in 1959--1963. Conversion of the IOON Reactor to produce byproduct steam for electrical production was authorized in September 1962. The 100K Area is a dual reactor site constructed in 1954--1955. Each reactor facility, K East and K West Reactor complexes, are almost identical in design, construction, and geographic orientation, and are separated by approximately 2,000 ft. This MIP includes all activities associated with (1) all structures and facilities located within the site area designated as the 100N Area, except for those facilities in which Kaiser Engineers Hanford and Operations Support Services organizations are in residence, and (2) those portions of structures and facilities located within the site area designated as 100K that are directly associated with the operation and maintenance of the fuel storage basins in 105 K East and 105 K West Buildings. Specifically excluded from this plan are all structures and facilities (or portions thereof) that have been assigned to, or operated by, organizations other than the 100N Reactor Plant Organization.

  16. A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL

    SciTech Connect

    Shain Doong; Estela Ong; Mike Atroshenko; Francis Lau; Mike Roberts

    2005-04-28

    Gas Technology Institute is developing a novel concept of membrane reactor coupled with a gasifier for high efficiency, clean and low cost production of hydrogen from coal. The concept incorporates a hydrogen-selective membrane within a gasification reactor for direct extraction of hydrogen from coal-derived synthesis gases. The objective of this project is to determine the technical and economic feasibility of this concept by screening, testing and identifying potential candidate membranes under high temperature, high pressure, and harsh environments of the coal gasification conditions. The best performing membranes will be selected for preliminary reactor design and cost estimates. To evaluate the performances of the candidate membranes under the gasification conditions, a high temperature/high pressure hydrogen permeation unit has been constructed in this project. The unit is designed to operate at temperatures up to 1100 C and pressures to 60 atm for evaluation of ceramic membranes such as mixed protonic-electronic conducting membrane. Several perovskite membranes based on the formulations of BCN (BaCe{sub 0.8}Nd{sub 0.2}O{sub 3-x}), BCY (BaCe{sub 0.8}Y{sub 0.2}O{sub 3-x}), Eu-doped SrCeO{sub 3} (SCE) and SrCe{sub 0.95}Tm{sub 0.05}O{sub 3} (SCTm) were successfully tested in the new permeation unit. During this reporting period, a thin BCN membrane supported on a porous BCN layer was fabricated. The objective was to increase the hydrogen flux with a further reduction of the thickness of the active membrane layer. The thinnest dense layer that could be achieved in our laboratory currently was about 0.2 mm. Nevertheless, the membrane was tested in the permeation unit and showed reasonable flux compared to the previous BCN samples of the same thickness. A long term durability test was conducted for a SCTm membrane with pure hydrogen in the feed side and nitrogen in the sweep side. The pressure was 1 bar and the temperature was around 1010 C. No decline of hydrogen flux was observed after continuous running of over 250 hours. This long term test indicates that the perovskite membrane has good thermal stability under the reducing conditions of the hydrogen atmosphere. A conceptual design of the membrane reactor configuration for a 1000 tons-per-day (TPD) coal gasifier was completed. The design considered a tubular membrane module located within the freeboard area of a fluidized bed gasifier. The membrane ambipolar conductivity was based on the value calculated from the measured permeation data. A membrane thickness of 25 micron was assumed in the calculation. The GTI's gasification model combined with a membrane reactor model were used to determine the dimensions of the membrane module. It appears that a membrane module can be configured within a fluidized bed gasifier without substantial increase of the gasifier dimensions.

  17. District Composite Report: Richland Parish. 2002-2003

    ERIC Educational Resources Information Center

    Louisiana State Department of Education, 2004

    2004-01-01

    Up to six years of data (the current year and the five previous years where available) are presented in the District Composite Report. This report is specific to Richland Parish. Each year, this report is updated by adding the most current year's data and deleting the data that are more than six years old. Incorporating longitudinal data in the…

  18. 78 FR 16713 - Board Meeting; April 16, 2013; Richland, WA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-18

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR WASTE TECHNICAL REVIEW BOARD Board Meeting; April 16, 2013; Richland, WA The U.S. Nuclear Waste Technical Review Board will meet to discuss DOE work on the vitrified HLW waste form for disposal in a repository. Pursuant...

  19. Hydrogen Production Via a Commercially Ready Inorganic Membrane Reactor

    SciTech Connect

    Paul K. T. Liu

    2006-09-30

    In the last report, we covered the experimental verification of the mathematical model we developed for WGS-MR, specifically in the aspect of CO conversion ratio, and the effect of the permeate sweep. Bench-top experimental study has been continuing in this period to verify the remaining aspects of the reactor performance, including hydrogen recovery ratio, hydrogen purity and CO contaminant level. Based upon the comparison of experimental vs simulated results in this period along with the results reported in the last period, we conclude that our mathematical model can predict reliably all aspects of the membrane reactor performance for WGS using typical coal gasifier off-gas as feed under the proposed operating condition. In addition to 250 C, the experimental study at 225 C was performed. As obtained at 250 C, the predicted values match well with the experimental results at this lower temperature. The pretreatment requirement in our proposed WGS-MR process can be streamlined to the particulate removal only. No excess water beyond the stoichiometric requirement for CO conversion is necessary; thus, power generation efficiency can be maximized. PROX will be employed as post-treatment for the elimination of trace CO. Since the CO contaminant level from our WGS-MR is projected to be 20-30 ppm, PROX can be implemented economically and reliably to deliver hydrogen with <10 ppm CO to meet the spec for PEM fuel cell. This would be a more cost effective solution than the production of on-spec hydrogen without the use of prost treatment. WGS reaction in the presence of sulfur can be accomplished with the use of the Co/MoS{sub 2} catalyst. This catalyst has been employed industrially as a sour gas shift catalyst. Our mathematical simulation on WGS-MR based upon the suggested pre- and post-treatment has demonstrated that a nearly complete CO conversion (i.e., 99+%) can be accomplished. Although conversion vs production cost may play an important role in an overall process optimization, no cost optimization has been taken into consideration presently. We estimate that {approx}90% of the hydrogen produced from the H{sub 2}+CO in the coal gasifier off-gas can be recovered via our proposed WGS-MR process. Its purity level ranges from 80 to 92% depending upon the H{sub 2}/CO{sub 2} selectivity of 10 to 25 respectively. If the purity of 95% is required, the hydrogen recovery ratio will drop to {approx}80% level for the membrane with H{sub 2}/CO{sub 2} = 25.

  20. Hydrogen Production via a Commerically Ready Inorganic membrane Reactor

    SciTech Connect

    Paul Liu

    2007-06-30

    It has been known that use of the hydrogen selective membrane as a reactor (MR) could potentially improve the efficiency of the water shift reaction (WGS), one of the least efficient unit operations for production of high purity hydrogen from syngas. However, no membrane reactor technology has been reduced to industrial practice thus far, in particular for a large-scale operation. This implementation and commercialization barrier is attributed to the lack of a commercially viable hydrogen selective membrane with (1) material stability under the application environment and (2) suitability for large-scale operation. Thus, in this project, we have focused on (1) the deposition of the hydrogen selective carbon molecular sieve (CMS) membrane we have developed on commercially available membranes as substrate, and (2) the demonstration of the economic viability of the proposed WGS-MR for hydrogen production from coal-based syngas. The commercial stainless steel (SS) porous substrate (i.e., ZrO{sub 2}/SS from Pall Corp.) was evaluated comprehensively as the 1st choice for the deposition of the CMS membrane for hydrogen separation. The CMS membrane synthesis protocol we developed previously for the ceramic substrate was adapted here for the stainless steel substrate. Unfortunately no successful hydrogen selective membranes had been prepared during Yr I of this project. The characterization results indicated two major sources of defect present in the SS substrate, which may have contributed to the poor CMS membrane quality. Near the end of the project period, an improved batch of the SS substrate (as the 2nd generation product) was received from the supplier. Our characterization results confirm that leaking of the crimp boundary no longer exists. However, the thermal stability of the ZrO{sub 2}/SS substrate through the CMS membrane preparation condition must be re-evaluated in the future. In parallel with the SS membrane activity, the preparation of the CMS membranes supported on our commercial ceramic membrane for large-scale applications, such as coal-based power generation/hydrogen production, was also continued. A significant number (i.e., 98) of full-scale membrane tubes have been produced with an on-spec ratio of >76% during the first production trial. In addition, we have verified the functional performance and material stability of this hydrogen selective CMS membrane with a hydrocracker purge gas stream at a refinery pilot testing facility. No change in membrane performance was noted over the >100 hrs of testing conducted in the presence of >30% H{sub 2}S, >5,000 ppm NH{sub 3} (estimated), and heavy hydrocarbons on the order of 25%. The excellent stability of our hydrogen selective CMS membrane opens the door for its use in WGS-MR with a significantly reduced requirement of the feedstock pretreatment.

  1. From discovery to production: Scale-out of continuous flow meso reactors

    PubMed Central

    Parracho, Ana I R

    2009-01-01

    Summary A continuous flow parallel reactor system has been developed to provide a rapid and seamless transition from the discovery phase and production phase of chemical synthesis, particularly in low volume-high value pharmaceuticals production. Using a single fixed bed catalytic meso reactor, reactions can be screened on a small discovery scale over short time scales. The intensified process produces sufficient material for a full analysis. By replication of the single reactor in parallel, the same chemistry can be achieved on a larger scale, on a small footprint and without the mass and heat transport limitations of reactor scale-out in batch. PMID:19590741

  2. Annual Energy Consumption Analysis Report for Richland Middle School

    SciTech Connect

    Liu, Bing

    2003-12-18

    Richland Middle School is a single story, 90,000 square feet new school located in Richland, WA. The design team proposed four HVAC system options to serve the building. The proposed HVAC systems are listed as following: (1) 4-pipe fan coil units served by electrical chiller and gas-fired boilers, (2) Ground-source closed water loop heat pumps with water loop heat pumps with boiler and cooling tower, and (3) VAV system served by electrical chiller and gas-fired boiler. This analysis estimates the annual energy consumptions and costs of each system option, in order to provide the design team with a reasonable basis for determining which system is most life-cycle cost effective. eQuest (version 3.37), a computer-based energy simulation program that uses the DOE-2 simulation engine, was used to estimate the annual energy costs.

  3. Liquid phase methanol reactor staging process for the production of methanol

    DOEpatents

    Bonnell, Leo W.; Perka, Alan T.; Roberts, George W.

    1988-01-01

    The present invention is a process for the production of methanol from a syngas feed containing carbon monoxide, carbon dioxide and hydrogen. Basically, the process is the combination of two liquid phase methanol reactors into a staging process, such that each reactor is operated to favor a particular reaction mechanism. In the first reactor, the operation is controlled to favor the hydrogenation of carbon monoxide, and in the second reactor, the operation is controlled so as to favor the hydrogenation of carbon dioxide. This staging process results in substantial increases in methanol yield.

  4. Assemblies with both target and fuel pins in an isotope-production reactor

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium target material is placed in pins adjacent to fuel pins in order to increase the tritium production rate.

  5. Fuel pins with both target and fuel pellets in an isotope-production reactor

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium in a fast breeder reactor cooled with liquid metal. Lithium target pellets are placed in close contact with fissile fuel pellets in order to increase the tritium production rate.

  6. Action Plan for updated Chapter 15 Accident Analysis in the SRS Production Reactor SAR

    SciTech Connect

    Hightower, N.T. III; Burnett, T.W.

    1989-11-15

    This report describes the Action Plan for the upgrade of the Chapter 15 Accident Analysis in the SRS Production Reactor SAR required for K-Restart. This Action Plan will be updated periodically to reflect task accomplishments and issue resolutions.

  7. Comparison of actinide production in traveling wave and pressurized water reactors

    SciTech Connect

    Osborne, A.G.; Smith, T.A.; Deinert, M.R.

    2013-07-01

    The geopolitical problems associated with civilian nuclear energy production arise in part from the accumulation of transuranics in spent nuclear fuel. A traveling wave reactor is a type of breed-burn reactor that could, if feasible, reduce the overall production of transuranics. In one possible configuration, a cylinder of natural or depleted uranium would be subjected to a fast neutron flux at one end. The neutrons would transmute the uranium, producing plutonium and higher actinides. Under the right conditions, the reactor could become critical, at which point a self-stabilizing fission wave would form and propagate down the length of the reactor cylinder. The neutrons from the fission wave would burn the fissile nuclides and transmute uranium ahead of the wave to produce additional fuel. Fission waves in uranium are driven largely by the production and fission of {sup 239}Pu. Simulations have shown that the fuel burnup can reach values greater than 400 MWd/kgIHM, before fission products poison the reaction. In this work we compare the production of plutonium and minor actinides produced in a fission wave to that of a UOX fueled light water reactor, both on an energy normalized basis. The nuclide concentrations in the spent traveling wave reactor fuel are computed using a one-group diffusion model and are verified using Monte Carlo simulations. In the case of the pressurized water reactor, a multi-group collision probability model is used to generate the nuclide quantities. We find that the traveling wave reactor produces about 0.187 g/MWd/kgIHM of transuranics compared to 0.413 g/MWd/kgIHM for a pressurized water reactor running fuel enriched to 4.95 % and burned to 50 MWd/kgIHM. (authors)

  8. Optimization of a flat plate glass reactor for mass production of Nannochloropsis sp. outdoors.

    PubMed

    Richmond, A; Cheng-Wu, Z

    2001-02-23

    The relationships between areal (g m(-2) per day) and volumetric (g l(-1) per day) productivity of Nannochloropsis sp. as affected by the light-path (ranging from 1.3 to 17.0 cm) of a vertical flat plate glass photobioreactor were elucidated. In general, the shorter the length of the light-path (LP), the smaller the areal volume and the higher the volumetric productivity. The areal productivity in relation to the light-path, in contrast, yielded an optimum curve, the highest areal productivity was obtained in a 10 cm LP reactor, which is regarded, therefore, optimal for mass production of Nannochloropsis. An attempt was made to identify criteria by which to assess the efficiency of a photobioreactor in utilizing strong incident energy. Two basic factors which relate to reactor efficiency and its cost-effectiveness have been defined as (a) the total illuminated surface required to produce a set quantity of product and (b) culture volume required to produce that quantity. As a general guide line, the lower these values are, the more efficient and cost-effective the reactor would be. An interesting feature of this analysis rests with the fact that an open raceways is as effective in productivity per illuminated area as a flat-plate reactor with an optimal light path, both cultivation systems requiring ca. 85 m(2) of illuminated surface to produce 1 kg dry cell mass of Nannochloropsis sp. per day. The difference in light utilization efficiency between the two very different production systems involves three aspects - first, the open raceway requires ca. 6 times greater volume than the 10 cm flat plate reactor to produce the same quantity of cell-mass. Second, the total ground area (i.e. including the ground area between reactors) for the vertical flat plate reactor is less than one half of that occupied by an open raceway, indicating the former is more efficient, photosynthetically, compared with the latter. Finally, the harvested cell density is close to one order of magnitude higher in the flat plate reactor, which carries economic significance. The advantage of vertical lamination of photoautotrophic cells provided by vertical plate reactors, is thereby clearly seen. The optimal population density (i.e. which results in the highest areal productivity) in the 10 cm plate reactor was obtained by a daily harvest of 10% of culture volume, yielding an annual average of ca. 12.1 g dry wt. m(-2) per day (on the basis of the overall illuminated reactor surfaces, i.e. front and back) or 240 mg l(-1) per day. PMID:11173093

  9. Biological production of ethanol from coal. Task 4 report, Continuous reactor studies

    SciTech Connect

    Not Available

    1992-10-01

    The production of ethanol from synthesis gas by the anaerobic bacterium C. ljungdahlii has been demonstrated in continuous stirred tank reactors (CSTRs), CSTRs with cell recycle and trickle bed reactors. Various liquid media were utilized in these studies including basal medium, basal media with 1/2 B-vitamins and no yeast extract and a medium specifically designed for the growth of C. ljungdahlii in the CSTR. Ethanol production was successful in each of the three reactor types, although trickle bed operation with C. ljungdahlii was not as good as with the stirred tank reactors. Operation in the CSTR with cell recycle was particularly promising, producing 47 g/L ethanol with only minor concentrations of the by-product acetate.

  10. Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

    SciTech Connect

    Asner, David M.; Burns, Kimberly A.; Campbell, Luke W.; Greenfield, Bryce A.; Kos, Marek S.; Orrell, John L.; Schram, Malachi; VanDevender, Brent A.; Wood, Lynn S.; Wootan, David W.

    2015-03-01

    The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

  11. Summary of near-term options for Russian plutonium production reactors

    SciTech Connect

    Newman, D.F.; Gesh, C.J.; Love, E.F.; Harms, S.L.

    1994-07-01

    The Russian Federation desires to phase out the production of weapons-grade plutonium. To this end, ten graphite-moderated, water-cooled reactors have been shut down during the last several years. However, complete cessation of plutonium production is impeded because the three operating Russian reactors supply district heat and electricity to the Tomsk and Krasnoyarsk regions in addition to producing weapon-grade plutonium. In August 1992 the Russian Federation Ministry of Atomic Energy (MINATOM) and the Russian Nuclear Regulatory Agency (GAN) requested U.S. assistance for achieving a cessation of weapons-grade plutonium production, placing the plutonium production reactors under safeguards, and conducting a program to evaluate and assist in the upgrade of plant safety. As a result of that and subsequent communications, Secretary O`Leary and Minister Mikhailov have signed a protocol that expressed their desire to shut down the three remaining plutonium production reactors as soon as possible by replacing them with alternate energy sources. In the meantime, both MINATOM and the Department of Energy (DOE) are concerned about the safety of the plants as well as the difficulty in ceasing the production of plutonium as long as the plants continue to operate. A military subsidy has been provided for operation of the production reactor complex. Revenues received for providing district heat and electricity are insufficient to cover costs for the current natural uranium metal fuel cycle. A more economical fuel cycle is needed for civilian operations.

  12. Optimization of outdoor cultivation in flat panel airlift reactors for lipid production by Chlorella vulgaris.

    PubMed

    Münkel, Ronja; Schmid-Staiger, Ulrike; Werner, Achim; Hirth, Thomas

    2013-11-01

    Microalgae are discussed as a potential renewable feedstock for biofuel production. The production of highly concentrated algae biomass with a high fatty acid content, accompanied by high productivity with the use of natural sunlight is therefore of great interest. In the current study an outdoor pilot plant with five 30 L Flat Panel Airlift reactors (FPA) installed southwards were operated in 2011 in Stuttgart, Germany. The patented FPA reactor works on the basis of an airlift loop reactor and offers efficient intermixing for homogeneous light distribution. A lipid production process with the microalgae Chlorella vulgaris (SAG 211-12), under nitrogen and phosphorous deprivation, was established and evaluated in regard to the fatty acid content, fatty acid productivity and light yield. In the first set of experiments limitations caused by restricted CO₂ availability were excluded by enriching the media with NaOH. The higher alkalinity allows a higher CO₂ content of supplied air and leads to doubling of fatty acid productivity. The second set of experiments focused on how the ratio of light intensity to biomass concentration in the reactor impacts fatty acid content, productivity and light yield. The specific light availability was specified as mol photons on the reactor surface per gram biomass in the reactor. This is the first publication based on experimental data showing the quantitative correlation between specific light availability, fatty acid content and biomass light yield for a lipid production process under nutrient deprivation and outdoor conditions. High specific light availability leads to high fatty acid contents. Lower specific light availability increases fatty acid productivity and biomass light yield. An average fatty acid productivity of 0.39 g L⁻¹  day⁻¹ for a 12 days batch process with a final fatty acid content of 44.6% [w/w] was achieved. Light yield of 0.4 g mol photons⁻¹ was obtained for the first 6 days of cultivation. PMID:23616347

  13. A packed bed membrane reactor for production of biodiesel using activated carbon supported catalyst.

    PubMed

    Baroutian, Saeid; Aroua, Mohamed K; Raman, Abdul Aziz A; Sulaiman, Nik M N

    2011-01-01

    In this study, a novel continuous reactor has been developed to produce high quality methyl esters (biodiesel) from palm oil. A microporous TiO2/Al2O3 membrane was packed with potassium hydroxide catalyst supported on palm shell activated carbon. The central composite design (CCD) of response surface methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst amount and cross flow circulation velocity on the production of biodiesel in the packed bed membrane reactor. The highest conversion of palm oil to biodiesel in the reactor was obtained at 70 °C employing 157.04 g catalyst per unit volume of the reactor and 0.21 cm/s cross flow circulation velocity. The physical and chemical properties of the produced biodiesel were determined and compared with the standard specifications. High quality palm oil biodiesel was produced by combination of heterogeneous alkali transesterification and separation processes in the packed bed membrane reactor. PMID:20888219

  14. Stable hydrogen production by methane steam reforming in a two zone fluidized bed reactor: Experimental assessment

    NASA Astrophysics Data System (ADS)

    Pérez-Moreno, L.; Soler, J.; Herguido, J.; Menéndez, M.

    2013-12-01

    The Two Zone Fluidized Bed Reactor concept is proposed for hydrogen production via the steam reforming of methane (SRM) including integrated catalyst regeneration. In order to study the effect of the contact mode, the oxidative SRM has been carried out over a Ni/Al2O3 catalyst using a fixed bed reactor (fBR), a conventional fluidized-bed reactor (FBR) and the proposed two-zone fluidized bed reactor (TZFBR). The technical feasibility of these reactors has been studied experimentally, investigating their performance (CH4 conversion, CO and H2 selectivity, and H2 global yield) and stability under different operating conditions. Coke generation in the process has been verified by several techniques. A stable performance was obtained in the TZFBR, where coke formation was counteracted with continuous catalyst regeneration. The viability of the TZFBR for carrying out this process with a valuable global yield to hydrogen is demonstrated.

  15. Interim Safe Storage of Plutonium Production Reactors at the US DOE Hanford Site - 13438

    SciTech Connect

    Schilperoort, Daryl L.; Faulk, Darrin

    2013-07-01

    Nine plutonium production reactors located on DOE's Hanford Site are being placed into an Interim Safe Storage (ISS) period that extends to 2068. The Environmental Impact Statement (EIS) for ISS [1] was completed in 1993 and proposed a 75-year storage period that began when the EIS was finalized. Remote electronic monitoring of the temperature and water level alarms inside the safe storage enclosure (SSE) with visual inspection inside the SSE every 5 years are the only planned operational activities during this ISS period. At the end of the ISS period, the reactor cores will be removed intact and buried in a landfill on the Hanford Site. The ISS period allows for radioactive decay of isotopes, primarily Co-60 and Cs-137, to reduce the dose exposure during disposal of the reactor cores. Six of the nine reactors have been placed into ISS by having an SSE constructed around the reactor core. (authors)

  16. Supplying the nuclear arsenal: Production reactor technology, management, and policy, 1942--1992

    SciTech Connect

    Carlisle, R.P.; Zenzen, J.M.

    1994-01-01

    This book focuses on the lineage of America`s production reactors, those three at Hanford and their descendants, the reactors behind America`s nuclear weapons. The work will take only occasional sideways glances at the collateral lines of descent, the reactor cousins designed for experimental purposes, ship propulsion, and electric power generation. Over the decades from 1942 through 1992, fourteen American production reactors made enough plutonium to fuel a formidable arsenal of more than twenty thousand weapons. In the last years of that period, planners, nuclear engineers, and managers struggled over designs for the next generation of production reactors. The story of fourteen individual machines and of the planning effort to replace them might appear relatively narrow. Yet these machines lay at the heart of the nation`s nuclear weapons complex. The story of these machines is the story of arming the winning weapon, supplying the nuclear arms race. This book is intended to capture the history of the first fourteen production reactors, and associated design work, in the face of the end of the Cold War.

  17. Analysis of fission-product effects in a Fast Mixed-Spectrum Reactor concept

    SciTech Connect

    White, J.R.; Burns, T.J.

    1980-02-01

    The Fast Mixed-Spectrum Reactor (FMSR) concept has been proposed by BNL as a means of alleviating certain nonproliferation concerns relating to civilian nuclear power. This breeder reactor concept has been tailored to operate on natural uranium feed (after initial startup), thus eliminating the need for fuel reprocessing. The fissile material required for criticality is produced, in situ, from the fertile feed material. This process requires that large burnup and fluence levels be achievable, which, in turn, necessarily implies that large fission-product inventories will exist in the reactor. It was the purpose of this study to investigate the effects of large fission-product inventories and to analyze the effect of burnup on fission-product nuclide distributions and effective cross sections. In addition, BNL requested that a representative 50-group fission-product library be generated for use in FMSR design calculations.

  18. Fast-quench reactor for hydrogen and elemental carbon production from natural gas and other hydrocarbons

    DOEpatents

    Detering, Brent A.; Kong, Peter C.

    2006-08-29

    A fast-quench reactor for production of diatomic hydrogen and unsaturated carbons is provided. During the fast quench in the downstream diverging section of the nozzle, such as in a free expansion chamber, the unsaturated hydrocarbons are further decomposed by reheating the reactor gases. More diatomic hydrogen is produced, along with elemental carbon. Other gas may be added at different stages in the process to form a desired end product and prevent back reactions. The product is a substantially clean-burning hydrogen fuel that leaves no greenhouse gas emissions, and elemental carbon that may be used in powder form as a commodity for several processes.

  19. Isotopic evidence for nitrous oxide production pathways in a partial nitritation-anammox reactor.

    PubMed

    Harris, Eliza; Joss, Adriano; Emmenegger, Lukas; Kipf, Marco; Wolf, Benjamin; Mohn, Joachim; Wunderlin, Pascal

    2015-10-15

    Nitrous oxide (N2O) production pathways in a single stage, continuously fed partial nitritation-anammox reactor were investigated using online isotopic analysis of offgas N2O with quantum cascade laser absorption spectroscopy (QCLAS). N2O emissions increased when reactor operating conditions were not optimal, for example, high dissolved oxygen concentration. SP measurements indicated that the increase in N2O was due to enhanced nitrifier denitrification, generally related to nitrite build-up in the reactor. The results of this study confirm that process control via online N2O monitoring is an ideal method to detect imbalances in reactor operation and regulate aeration, to ensure optimal reactor conditions and minimise N2O emissions. Under normal operating conditions, the N2O isotopic site preference (SP) was much higher than expected - up to 40‰ - which could not be explained within the current understanding of N2O production pathways. Various targeted experiments were conducted to investigate the characteristics of N2O formation in the reactor. The high SP measurements during both normal operating and experimental conditions could potentially be explained by a number of hypotheses: i) unexpectedly strong heterotrophic N2O reduction, ii) unknown inorganic or anammox-associated N2O production pathway, iii) previous underestimation of SP fractionation during N2O production from NH2OH, or strong variations in SP from this pathway depending on reactor conditions. The second hypothesis - an unknown or incompletely characterised production pathway - was most consistent with results, however the other possibilities cannot be discounted. Further experiments are needed to distinguish between these hypotheses and fully resolve N2O production pathways in PN-anammox systems. PMID:26164660

  20. Production of Sn-117m in the BR2 and HFIR Research Reactors

    SciTech Connect

    Ponsard, B.; Srivastava, S.; Garland, M.; Knapp, R.; Mirzadeh, S.; Mausner, L.F.

    2009-07-01

    The BR2 reactor is a 100 MW{sub th} high-flux 'materials testing reactor', which produces a wide range of radioisotopes for various applications in nuclear medicine and industry. Tin-117m ({sup 117m}Sn), a promising radionuclide for therapeutic applications, and its production have been validated in the BR2 reactor. In contrast to therapeutic beta emitters, {sup 117m}Sn decays via isomeric transition with the emission of monoenergetic conversion electrons which are effective for metastatic bone pain palliation and radiosynovectomy with lesser damage to the bone marrow and the healthy tissues. Furthermore, the emitted gamma photons are ideal for imaging and dosimetry.

  1. High flux Particle Bed Reactor systems for rapid transmutation of actinides and long lived fission products

    SciTech Connect

    Powell, J.; Ludewig, H.; Maise, G.; Steinberg, M.; Todosow, M.

    1993-08-01

    An initial assessment of several actinide/LLFP burner concepts based on the Particle Bed Reactor (PBR) is described. The high power density/flux level achievable with the PBR make it an attractive candidate for this application. The PBR based actinide burner concept also possesses a number of safety and economic benefits relative to other reactor based transmutation approaches including a low inventory of radionuclides, and high integrity, coated fuel particles which can withstand extremely high in temperatures while retaining virtually all fission products. In addition the reactor also posesses a number of ``engineered safety features,`` which, along with the use of high temperature capable materials further enhance its safety characteristics.

  2. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    SciTech Connect

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  3. Reactor production and processing of radioisotopes for therapeutic applications in nuclear medicine

    SciTech Connect

    Knapp, F.F. Jr.; Mirzadeh, S.; Beets, A.L.

    1995-02-01

    Nuclear reactors continue to play an important role in providing radioisotopes for nuclear medicine. Many reactor-produced radioisotopes are ``neutron rich`` and decay by beta-emission and are thus of interest for therapeutic applications. This talk discusses the production and processing of a variety of reactor-produced radioisotopes of current interest, including those produced by the single neutron capture process, double neutron capture and those available from beta-decay of reactorproduced radioisotopes. Generators prepared from reactorproduced radioisotopes are of particular interest since repeated elution inexpensively provides many patient doses. The development of the alumina-based W-188/Re-188 generator system is discussed in detail.

  4. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    NASA Astrophysics Data System (ADS)

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-01

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor).

  5. REACTOR

    DOEpatents

    Christy, R.F.

    1961-07-25

    A means is described for co-relating the essential physical requirements of a fission chain reaction in order that practical, compact, and easily controllable reactors can be built. These objects are obtained by employing a composition of fissionsble isotope and moderator in fluid form in which the amount of fissionsble isotcpe present governs the reaction. The size of the reactor is no longer a critical factor, the new criterion being the concentration of the fissionable isotope.

  6. REACTOR

    DOEpatents

    Szilard, L.

    1963-09-10

    A breeder reactor is described, including a mass of fissionable material that is less than critical with respect to unmoderated neutrons and greater than critical with respect to neutrons of average energies substantially greater than thermal, a coolant selected from sodium or sodium--potassium alloys, a control liquid selected from lead or lead--bismuth alloys, and means for varying the quantity of control liquid in the reactor. (AEC)

  7. MHTGR: New production reactor summary of experience base

    SciTech Connect

    Not Available

    1988-03-01

    Worldwide interest in the Modular High-Temperature Gas-Cooled Reactor (MHTGR) stems from the capability of the system to retain the advanced fuel and thermal performance while providing unparalleled levels of safety. The small power level of the MHTGR and its passive systems give it a margin of safety not attained by other concepts being developed for power generation. This report covers the experience base for the key nuclear system, components, and processes related to the MHTGR-NPR. 9 refs., 39 figs., 9 tabs.

  8. The rate of decay of fresh fission products from a nuclear reactor

    NASA Astrophysics Data System (ADS)

    Dolan, David J.

    Determining the rate of decay of fresh fission products from a nuclear reactor is complex because of the number of isotopes involved, different types of decay, half-lives of the isotopes, and some isotopes decay into other radioactive isotopes. Traditionally, a simplified rule of 7s and 10s is used to determine the dose rate from nuclear weapons and can be to estimate the dose rate from fresh fission products of a nuclear reactor. An experiment was designed to determine the dose rate with respect to time from fresh fission products of a nuclear reactor. The experiment exposed 0.5 grams of unenriched Uranium to a fast and thermal neutron flux from a TRIGA Research Reactor (Lakewood, CO) for ten minutes. The dose rate from the fission products was measured by four Mirion DMC 2000XB electronic personal dosimeters over a period of six days. The resulting dose rate following a rule of 10s: the dose rate of fresh fission products from a nuclear reactor decreases by a factor of 10 for every 10 units of time.

  9. Process and reactor design for biophotolytic hydrogen production.

    PubMed

    Tamburic, Bojan; Dechatiwongse, Pongsathorn; Zemichael, Fessehaye W; Maitland, Geoffrey C; Hellgardt, Klaus

    2013-07-14

    The green alga Chlamydomonas reinhardtii has the ability to produce molecular hydrogen (H2), a clean and renewable fuel, through the biophotolysis of water under sulphur-deprived anaerobic conditions. The aim of this study was to advance the development of a practical and scalable biophotolytic H2 production process. Experiments were carried out using a purpose-built flat-plate photobioreactor, designed to facilitate green algal H2 production at the laboratory scale and equipped with a membrane-inlet mass spectrometry system to accurately measure H2 production rates in real time. The nutrient control method of sulphur deprivation was used to achieve spontaneous H2 production following algal growth. Sulphur dilution and sulphur feed techniques were used to extend algal lifetime in order to increase the duration of H2 production. The sulphur dilution technique proved effective at encouraging cyclic H2 production, resulting in alternating Chlamydomonas reinhardtii recovery and H2 production stages. The sulphur feed technique enabled photobioreactor operation in chemostat mode, resulting in a small improvement in H2 production duration. A conceptual design for a large-scale photobioreactor was proposed based on these experimental results. This photobioreactor has the capacity to enable continuous and economical H2 and biomass production using green algae. The success of these complementary approaches demonstrate that engineering advances can lead to improvements in the scalability and affordability of biophotolytic H2 production, giving increased confidence that H2 can fulfil its potential as a sustainable fuel of the future. PMID:23689756

  10. 33 CFR 100.1305 - Richland, Washington, west coast outboard championship hydro races.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable Waters COAST GUARD... Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

  11. 33 CFR 100.1305 - Richland, Washington, west coast outboard championship hydro races.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable Waters COAST GUARD... Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

  12. 33 CFR 100.1305 - Richland, Washington, west coast outboard championship hydro races.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable Waters COAST GUARD... Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

  13. 33 CFR 100.1305 - Richland, Washington, west coast outboard championship hydro races.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable Waters COAST GUARD... Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

  14. 33 CFR 100.1305 - Richland, Washington, west coast outboard championship hydro races.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable Waters COAST GUARD... Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

  15. Excerpt from {open_quotes}Summary of Near-Term Options for Russian Plutonium-Production Reactors{close_quotes}

    SciTech Connect

    1994-12-01

    The Russian Federation desires to stop producing weapons-grade plutonium. During the last several years, ten graphite-moderated, water-cooled, production reactors have been shut down. However, complete cessation of weapons-grade plutonium production is impeded by the fact that the last three operating Russian plutonium-production reactors supply electrical energy and district heat as well as produce plutonium. These reactors are major suppliers of heat in the Tomsk and Krasnoyarsk regions of Siberia.

  16. Air quality impact analysis in support of the new production reactor environmental impact statement

    SciTech Connect

    Hadley, D L

    1991-04-01

    The Pacific Northwest Laboratory (PNL) conducted this air quality impact analysis for the US Department of Energy (DOE). The purpose of this work was to provide Argonne National Laboratory (ANL) with the required estimates of ground-level concentrations of five criteria air pollutants at the Hanford Site boundary from each of the stationary sources associated with the new production reactor (NPR) and its supporting facilities. The DOE proposes to provide new production capacity for the primary production of tritium and secondary production of plutonium to support the US nuclear weapons program. Three alternative reactor technologies are being considered by DOE: the light-water reactor, the low-temperature, heavy-water reactor, and the modular high-temperature, gas-cooled reactor. In this study, PNL provided estimates of the impacts of the proposed action on the ground-level concentration of the criteria air pollutants for each of the alternative technologies. The criteria pollutants were sulfur dioxide, nitrogen dioxide, carbon monoxide, total suspended particulates, and particulates with a diameter of less than 10 microns. Ground-level concentrations were estimated for the peak construction phase activities expected to occur in 1997 and for the operational phase activities beginning in the year 2000. Ground-level concentrations of the primary air pollutants were estimated to be well below any of the applicable national or state ambient air quality standards. 12 refs., 19 tabs.

  17. Production of a Biopolymer at Reactor Scale: A Laboratory Experience

    ERIC Educational Resources Information Center

    Genc, Rukan; Rodriguez-Couto, Susana

    2011-01-01

    Undergraduate students of biotechnology became familiar with several aspects of bioreactor operation via the production of xanthan gum, an industrially relevant biopolymer, by "Xanthomonas campestris" bacteria. The xanthan gum was extracted from the fermentation broth and the yield coefficient and productivity were calculated. (Contains 2 figures.)

  18. REACTOR

    DOEpatents

    Roman, W.G.

    1961-06-27

    A pressurized water reactor in which automatic control is achieved by varying the average density of the liquid moderator-cooiant is patented. Density is controlled by the temperature and power level of the reactor ftself. This control can be effected by the use of either plate, pellet, or tubular fuel elements. The fuel elements are disposed between upper and lower coolant plenum chambers and are designed to permit unrestricted coolant flow. The control chamber has an inlet opening communicating with the lower coolant plenum chamber and a restricted vapor vent communicating with the upper coolant plenum chamber. Thus, a variation in temperature of the fuel elements will cause a variation in the average moderator density in the chamber which directly affects the power level of the reactor.

  19. REACTORS

    DOEpatents

    Spitzer, L. Jr.

    1961-10-01

    Thermonuclear reactors, methods, and apparatus are described for controlling and confining high temperature plasma. Main axial confining coils in combination with helical windings provide a rotational transform that avoids the necessity of a figure-eight shaped reactor tube. The helical windings provide a multipolar helical magnetic field transverse to the axis of the main axial confining coils so as to improve the effectiveness of the confining field by counteracting the tendency of the more central lines of force in the stellarator tube to exchange positions with the magnetic lines of force nearer the walls of the tube. (AEC)

  20. Production of activated carbon from coconut shell char in a fluidized bed reactor

    SciTech Connect

    Sai, P.M.S.; Ahmed, J.; Krishnaiah, K.

    1997-09-01

    Activated carbon is produced from coconut shell char using steam or carbon dioxide as the reacting gas in a 100 mm diameter fluidized bed reactor. The effect of process parameters such as reaction time, fluidizing velocity, particle size, static bed height, temperature of activation, fluidizing medium, and solid raw material on activation is studied. The product is characterized by determination of iodine number and BET surface area. The product obtained in the fluidized bed reactor is much superior in quality to the activated carbons produced by conventional processes. Based on the experimental observations, the optimum values of process parameters are identified.

  1. Tritium concentrations in the Columbia River at Richland

    SciTech Connect

    Dirkes, R.L.

    1993-01-01

    The concentrations of tritium in the Columbia River, which are measurable using special analytical techniques, have been decreasing during recent years. Tritium levels are significantly greater at the Richland Pumphouse downstream of the Hanford Site than upstream at Priest Rapids Dam. Tritium is known to enter the river along the Hanford Site as direct effluent discharges, which have been virtually eliminated, and through the seepage of ground water contaminated as a result of past operations. The seepage of contaminated ground water has continued, expanding over time to encompass a larger portion of the Hanford shoreline nearer to the downstream Columbia River monitoring station. Cross-sectional sampling of the river was conducted to determine the distribution of tritium across the river and evaluate the relationship between average tritium concentrations in the river and those measured by the downstream river sampling system.

  2. Routine environmental audit of the Hanford Site, Richland, Washington

    SciTech Connect

    Not Available

    1994-05-01

    This report documents the results of the routine environmental audit of the Hanford Site (Hanford), Richland, Washington. During this audit, the activities conducted by the audit team included reviews of internal documents an reports from previous audits and assessments; interviews with US Department of Energy (DOE), State of Washington regulatory, and contractor personnel; and inspections and observations of selected facilities and operations. The onsite portion of the audit was conducted May 2--13, 1994, by the DOE Office of Environmental Audit (EH-24), located within the Office of Environment, Safety and Health (EH). The audit evaluated the status of programs to ensure compliance with Federal, State, and local environmental laws and regulations; compliance with DOE orders, guidance, and directives; and conformance with accepted industry practices and standards of performance. The audit also evaluated the status and adequacy of the management systems developed to address environmental requirements.

  3. Effect of Catalytic Cylinders on Autothermal Reforming of Methane for Hydrogen Production in a Microchamber Reactor

    PubMed Central

    Yan, Yunfei; Guo, Hongliang; Zhang, Li; Zhu, Junchen; Yang, Zhongqing; Tang, Qiang; Ji, Xin

    2014-01-01

    A new multicylinder microchamber reactor is designed on autothermal reforming of methane for hydrogen production, and its performance and thermal behavior, that is, based on the reaction mechanism, is numerically investigated by varying the cylinder radius, cylinder spacing, and cylinder layout. The results show that larger cylinder radius can promote reforming reaction; the mass fraction of methane decreased from 26% to 21% with cylinder radius from 0.25 mm to 0.75 mm; compact cylinder spacing corresponds to more catalytic surface and the time to steady state is decreased from 40 s to 20 s; alteration of staggered and aligned cylinder layout at constant inlet flow rates does not result in significant difference in reactor performance and it can be neglected. The results provide an indication and optimize performance of reactor; it achieves higher conversion compared with other reforming reactors. PMID:25097877

  4. HYDROGEN PRODUCTION VIA A COMMERCIALLY READY INORGANIC MEMBRANE REACTOR

    SciTech Connect

    Paul K.T. Liu

    2004-07-21

    The porous stainless steel substrate commercially available from Pall offers great potential for large-scale membrane based high temperature gas separations. Our proposed project involves the deposition of the M&P carbon molecular sieve-based hydrogen membrane on AccuSep substrate as a membrane to reactor water-gas-shift reaction. However, the AccuSep substrate was originally designed for liquid phase applications . During the 1st half, this commercial substrate has been modified and improved with regard to its surface topography and end seals. The substrate is now suitable for the deposition of the CMS membrane for hydrogen separation according to the characterization we preformed. In addition, 40{angstrom} Al{sub 2}O{sub 3} membrane layers have been deposited on the improved AccuSep substrate successfully. The SEM, EDX and pore size distribution analysis indicate that the 40{angstrom} membrane is extremely thin, and defect free with a narrow pore size distribution around 40{angstrom} primarily. As the above results suggest, we have made significant progress in preparing a high quality nominal 40{angstrom} (actually 50{angstrom}) layer on the Pall substrate. During the 2nd half of Year 1, we will (1) continue this development work with a focus on eliminating the high pore size peak and (2) begin the CMS layer deposition on the 40{angstrom} deposited AccuSep.

  5. Hybrid fusion reactor for production of nuclear fuel with minimum radioactive contamination of the fuel cycle

    SciTech Connect

    Velikhov, E. P.; Kovalchuk, M. V.; Azizov, E. A. Ignatiev, V. V.; Subbotin, S. A. Tsibulskiy, V. F.

    2015-12-15

    The paper presents the results of the system research on the coordinated development of nuclear and fusion power engineering in the current century. Considering the increasing problems of resource procurement, including limited natural uranium resources, it seems reasonable to use fusion reactors as high-power neutron sources for production of nuclear fuel in a blanket. It is shown that the share of fusion sources in this structural configuration of the energy system can be relatively small. A fundamentally important aspect of this solution to the problem of closure of the fuel cycle is that recycling of highly active spent fuel can be abandoned. Radioactivity released during the recycling of the spent fuel from the hybrid reactor blanket is at least two orders of magnitude lower than during the production of the same number of fissile isotopes after the recycling of the spent fuel from a fast reactor.

  6. Hybrid fusion reactor for production of nuclear fuel with minimum radioactive contamination of the fuel cycle

    NASA Astrophysics Data System (ADS)

    Velikhov, E. P.; Kovalchuk, M. V.; Azizov, E. A.; Ignatiev, V. V.; Subbotin, S. A.; Tsibulskiy, V. F.

    2015-12-01

    The paper presents the results of the system research on the coordinated development of nuclear and fusion power engineering in the current century. Considering the increasing problems of resource procurement, including limited natural uranium resources, it seems reasonable to use fusion reactors as high-power neutron sources for production of nuclear fuel in a blanket. It is shown that the share of fusion sources in this structural configuration of the energy system can be relatively small. A fundamentally important aspect of this solution to the problem of closure of the fuel cycle is that recycling of highly active spent fuel can be abandoned. Radioactivity released during the recycling of the spent fuel from the hybrid reactor blanket is at least two orders of magnitude lower than during the production of the same number of fissile isotopes after the recycling of the spent fuel from a fast reactor.

  7. REACTOR

    DOEpatents

    Spitzer, L. Jr.

    1962-01-01

    The system conteraplates ohmically heating a gas to high temperatures such as are useful in thermonuclear reactors of the stellarator class. To this end the gas is ionized and an electric current is applied to the ionized gas ohmically to heat the gas while the ionized gas is confined to a central portion of a reaction chamber. Additionally, means are provided for pumping impurities from the gas and for further heating the gas. (AEC)

  8. Zero valent iron simultaneously enhances methane production and sulfate reduction in anaerobic granular sludge reactors.

    PubMed

    Liu, Yiwen; Zhang, Yaobin; Ni, Bing-Jie

    2015-05-15

    Zero valent iron (ZVI) packed anaerobic granular sludge reactors have been developed for improved anaerobic wastewater treatment. In this work, a mathematical model is developed to describe the enhanced methane production and sulfate reduction in anaerobic granular sludge reactors with the addition of ZVI. The model is successfully calibrated and validated using long-term experimental data sets from two independent ZVI-enhanced anaerobic granular sludge reactors with different operational conditions. The model satisfactorily describes the chemical oxygen demand (COD) removal, sulfate reduction and methane production data from both systems. Results show ZVI directly promotes propionate degradation and methanogenesis to enhance methane production. Simultaneously, ZVI alleviates the inhibition of un-dissociated H2S on acetogens, methanogens and sulfate reducing bacteria (SRB) through buffering pH (Fe(0) + 2H(+) = Fe(2+) + H2) and iron sulfide precipitation, which improve the sulfate reduction capacity, especially under deterioration conditions. In addition, the enhancement of ZVI on methane production and sulfate reduction occurs mainly at relatively low COD/ [Formula: see text] ratio (e.g., 2-4.5) rather than high COD/ [Formula: see text] ratio (e.g., 16.7) compared to the reactor without ZVI addition. The model proposed in this work is expected to provide support for further development of a more efficient ZVI-based anaerobic granular system. PMID:25867207

  9. Venting of fission products and shielding in thermionic nuclear reactor systems

    NASA Technical Reports Server (NTRS)

    Salmi, E. W.

    1972-01-01

    Most thermionic reactors are designed to allow the fission gases to escape out of the emitter. A scheme to allow the fission gases to escape is proposed. Because of the low activity of the fission products, this method should pose no radiation hazards.

  10. Assessement of Codes and Standards Applicable to a Hydrogen Production Plant Coupled to a Nuclear Reactor

    SciTech Connect

    M. J. Russell

    2006-06-01

    This is an assessment of codes and standards applicable to a hydrogen production plant to be coupled to a nuclear reactor. The result of the assessment is a list of codes and standards that are expected to be applicable to the plant during its design and construction.

  11. Zeolite Membrane Reactor for Water Gas Shift Reaction for Hydrogen Production

    SciTech Connect

    Lin, Jerry Y.S.

    2013-01-29

    Gasification of biomass or heavy feedstock to produce hydrogen fuel gas using current technology is costly and energy-intensive. The technology includes water gas shift reaction in two or more reactor stages with inter-cooling to maximize conversion for a given catalyst volume. This project is focused on developing a membrane reactor for efficient conversion of water gas shift reaction to produce a hydrogen stream as a fuel and a carbon dioxide stream suitable for sequestration. The project was focused on synthesizing stable, hydrogen perm-selective MFI zeolite membranes for high temperature hydrogen separation; fabricating tubular MFI zeolite membrane reactor and stable water gas shift catalyst for membrane reactor applications, and identifying experimental conditions for water gas shift reaction in the zeolite membrane reactor that will produce a high purity hydrogen stream. The project has improved understanding of zeolite membrane synthesis, high temperature gas diffusion and separation mechanisms for zeolite membranes, synthesis and properties of sulfur resistant catalysts, fabrication and structure optimization of membrane supports, and fundamentals of coupling reaction with separation in zeolite membrane reactor for water gas shift reaction. Through the fundamental study, the research teams have developed MFI zeolite membranes with good perm-selectivity for hydrogen over carbon dioxide, carbon monoxide and water vapor, and high stability for operation in syngas mixture containing 500 part per million hydrogen sulfide at high temperatures around 500°C. The research teams also developed a sulfur resistant catalyst for water gas shift reaction. Modeling and experimental studies on the zeolite membrane reactor for water gas shift reaction have demonstrated the effective use of the zeolite membrane reactor for production of high purity hydrogen stream.

  12. A molten Salt Am242M Production Reactor for Space Applications

    NASA Technical Reports Server (NTRS)

    Emrich, William

    2005-01-01

    The use of Am242m holds great promise for increasing the efficiency nuclear thermal rocket engines. Because Am242m has the highest fission cross section of any known isotope (1000's of barns), its extremely high reactivity may be used to directly heat a propellant gas with fission fragments. Since this isotope does not occur naturally, it must be bred in special production reactors designed for that purpose. The primary advantage to using molten salt reactors for breeding Am242m is that the reactors can be reprocessed continually yielding a constant rate of production of the isotope. Once built and initially fueled, the reactor will continually breed the additional fuel it needs to remain critical. The only feedstock required is a salt of U238. No enriched fuel is required during normal operation and all fissile material, except the Am242m, is maintained in a closed loop. For a reactor operating at 200 MW several kilograms of Am242m may be bred each year.

  13. Production of {sup 99}Mo using LEU and molybdenum targets in a 1 MW Triga reactor

    SciTech Connect

    Mo, S.C.

    1993-12-31

    The production of {sup 99}Mo using Low Enriched Uranium (LEU) and natural molybdenum targets in a 1 MW Triga reactor is investigated. The successive linear programming technique is applied to minimize the target loadings for different yield constraints. The irradiation time is related to the kinetics of the growth and decay of {sup 99}Mo. The feasibility of a neutron generated based {sup 99}Mo production system is discussed.

  14. Analysis of the operation of American Westinghouse PWR nuclear reactors during 1980. Monthly production diagrams

    NASA Astrophysics Data System (ADS)

    Bocquaire, H.

    1981-12-01

    Availability and production are indicated for American nuclear reactors according to power rating. The number of incidents and length of stoppage is given for each type of system and each installation. Production rose six points overall compared with 1979. The range 1000 MW progressed 13 points (65% production capacity reached). The 700 to 1000 MW range improved by 5 points, despite many repairs to steam generators and almost total stoppage of one plant (48% production). The 400 to 600 MW range lost 12 points due to stops for recharging and many repairs to steam generators.

  15. Design and analysis of an immobilized cell reactor with simultaneous product separation: ethanol from whey lactose

    SciTech Connect

    Dale, M.C.

    1983-01-01

    The simultaneous separation of volatile fermentation products from product inhibited fermentations can increase the productivity of a bioreactor by reducing the product concentration in the bioreactor. In this work, a simultaneous tubular reactor separator is developed in which the volatile product is removed from the reacting broth by an inert gas phase. The immobilized cell reactor separator (ICRS) consists of two column reactors: a cocurrent enriching column followed by an countercurrent stripping column. The application of the ICRS concept to the ethanol from whey lactose fermentation was investigated using the yeast Kluyveromyces fragilis 2415. An equilibrium stage model of the ICRS was developed including a surface renewal term for an adsorbed monolayer of reacting cells. This model demonstrated the effect of important operational parameters including temperature, pressure, and gas flow rates. Experimental results using yeast adsorbed to 1/4'' ceramic saddles were somewhat unsatisfactory but very high productivities, cell densities, and separation efficiency were obtained using an absorbant column packing in a gas continuous operating mode.

  16. Fission product release phenomena during core melt accidents in metal fueled heavy water reactors

    SciTech Connect

    Ellison, P G; Hyder, M L; Monson, P R; Randolph, H W; Hagrman, D L; McClure, P R; Leonard, M T

    1990-01-01

    The phenomena that determine fission product release rates from a core melting accident in a metal-fueled, heavy water reactor are described in this paper. This information is obtained from the analysis of the current metal fuel experimental data base and from the results of analytical calculations. Experimental programs in place at the Savannah River Site are described that will provide information to resolve uncertainties in the data base. The results of the experiments will be incorporated into new severe accident computer codes recently developed for this reactor design. 47 refs., 4 figs.

  17. Fission-product data analysis from actinide samples exposed in the Dounreay Prototype Fast Reactor

    SciTech Connect

    Murphy, B.D.; Dickens, J.K.; Walker, R.L.; Newton, T.D.

    1994-12-31

    Since 1979 a cooperative agreement has been in effect between the United States and the United Kingdom to investigate the irradiation of various actinide species placed in the core of the Dounreay Prototype Fast Reactor (PFR). The irradiated species were isotopes of thorium, protactinium, uranium, neptunium, plutonium, americium, and curium. A set of actinide samples (mg quantities) was exposed to about 490 effective full power days (EFPD) of reactor operations. The fission-product results are reported here. The actinide results will be report elsewhere.

  18. Methane production enhancement by an independent cathode in integrated anaerobic reactor with microbial electrolysis.

    PubMed

    Cai, Weiwei; Han, Tingting; Guo, Zechong; Varrone, Cristiano; Wang, Aijie; Liu, Wenzong

    2016-05-01

    Anaerobic digestion (AD) represents a potential way to achieve energy recovery from waste organics. In this study, a novel bioelectrochemically-assisted anaerobic reactor is assembled by two AD systems separated by anion exchange membrane, with the cathode placing in the inside cylinder (cathodic AD) and the anode on the outside cylinder (anodic AD). In cathodic AD, average methane production rate goes up to 0.070mLCH4/mL reactor/day, which is 2.59times higher than AD control reactor (0.027m(3)CH4/m(3)/d). And COD removal is increased ∼15% over AD control. When changing to sludge fermentation liquid, methane production rate has been further increased to 0.247mLCH4/mL reactor/day (increased by 51.53% comparing with AD control). Energy recovery efficiency presents profitable gains, and economic revenue from increased methane totally self-cover the cost of input electricity. The study indicates that cathodic AD could cost-effectively enhance methane production rate and degradation of glucose and fermentative liquid. PMID:26913643

  19. Toward continuous and scalable production of colloidal nanocrystals by switching from batch to droplet reactors.

    PubMed

    Niu, Guangda; Ruditskiy, Aleksey; Vara, Madeline; Xia, Younan

    2015-08-21

    Colloidal nanocrystals are finding widespread use in a wide variety of applications ranging from catalysis to photonics, electronics, energy harvesting/conversion/storage, environment protection, information storage, and biomedicine. Despite the large number of successful demonstrations, there still exists a significant gap between academic studies and industrial applications owing to the lack of an ability to produce colloidal nanocrystals in large quantities without losing control over their properties. Droplet reactors have shown great potential for the continuous and scalable production of colloidal nanocrystals with uniform and well-controlled sizes, shapes, structures, and compositions. In this tutorial review, we begin with rationales for the use of droplet reactors as a new platform to scale up the production of colloidal nanocrystals, followed by discussions of the general concepts and technical challenges in applying droplet reactors to the synthesis of nanocrystals, including droplet formation, introduction and mixing of reagents, management of gaseous species, and interfacial adsorption. At the end, we use a set of examples to highlight the unique capabilities of droplet reactors for the high-volume production of colloidal nanocrystals in the setting of both homogeneous nucleation and seed-mediated growth. PMID:25757727

  20. Gaseous fission product management for molten salt reactors and vented fuel systems

    SciTech Connect

    Messenger, S. J.; Forsberg, C.; Massie, M.

    2012-07-01

    Fission gas disposal is one of the unresolved difficulties for Molten Salt Reactors (MSRs) and advanced reactors with vented fuel systems. As these systems operate, they produce many radioactive isotopes of xenon and krypton (e.g. {sup 135}Xe t{sub 1/2} = 9.14 hours and {sup 85}Kr t{sub 1/2}= 10.73 years). Removing these gases proves vital to the success of such reactor designs for two reasons. First, the gases act as large neutron sinks which decrease reactivity and must be counterbalanced by increasing fuel loading. Second, for MSRs, inert fission product gases naturally separate quickly from high temperature salts, thus creating high vapor pressure which poses safety concerns. For advanced reactors with solid vented fuel, the gases are allowed to escape into an off-gas system and thus must be managed. Because of time delays in transport of fission product gases in vented fuel systems, some of the shorter-lived radionuclides will decay away thereby reducing the fission gas source term relative to an MSR. To calculate the fission gas source term of a typical molten salt reactor, we modeled a 1000 MWe graphite moderated thorium MSR similar to that detailed in Mathieu et al. [1]. The fuel salt used in these calculations was LiF (78 mole percent) - (HN)F 4 (22 mole percent) with a heavy nuclide composition of 3.86% {sup 233}U and 96.14% {sup 232}Th by mass. Before we can remove the fission product gases produced by this reactor configuration, we must first develop an appropriate storage mechanism. The gases could be stored in pressurized containers but then one must be concerned about bottle failure. Methods to trap noble gases in matrices are expensive and complex. Alternatively, there are direct storage/disposal options: direct injection into the Earth or injecting a grout-based product into the Earth. Advances in drilling technologies, hydro fracture technologies, and methods for the sequestration of carbon dioxide from fossil fuel plants are creating new options for disposal of fission gas wastes. In each option, lithostatic pressure, a kilometer or more underground, eliminates the pressure driving force for noble gas release and dissolves any untrapped gas in deep groundwater or into incorporated solid waste forms. The options, challenges, and potential for these methods to dispose of gaseous fission products are described. With this research, we hope to help both MSRs and other advanced reactors come one step closer to commercialization. (authors)

  1. Production of Biodiesel at Kinetic Limit Achieved in a Centrifugal Reactor/Separator

    SciTech Connect

    McFarlane, Joanna; Tsouris, Costas; Birdwell Jr, Joseph F; Lee, Denise L; Jennings, Hal L; Pahmer Boitrago, Amy M; Terpstra, Sarah M

    2010-01-01

    The kinetics of the transesterification of soybean oil has been investigated in a centrifugal reactor at temperatures from 45 to 80 C and pressures up to 2.6 bar using gas chromatography flame ionization detection (GC-FID) and infrared (IR) spectroscopy. The yields of product methyl esters were quantified using IR, proton Nuclear Magnetic Resonance (H1NMR), and viscosity measurements and were found to achieve 90% of the yield in 2 min; however, to meet ASTM specifications with one pass through the reactor, a 15 min residence time was needed. Performance was improved by sequential reactions, allowing separation of by-product glycerine and injection of additional small aliquots of methanol. The kinetics was modeled using a three-step mechanism of reversible reactions, which was used to predict performance at commercial scale. The mechanism correctly predicted the exponential decline in reaction rate as the concentration of the products allowed significant reverse reactions to occur.

  2. Measurement of tritium production rate distribution for a fusion-fission hybrid conceptual reactor

    NASA Astrophysics Data System (ADS)

    Wang, Xin-Hua; Guo, Hai-Ping; Mou, Yun-Feng; Zheng, Pu; Liu, Rong; Yang, Xiao-Fei; Yang, Jian

    2013-05-01

    A fusion-fission hybrid conceptual reactor is established. It consists of a DT neutron source and a spherical shell of depleted uranium and hydrogen lithium. The tritium production rate (TPR) distribution in the conceptual reactor was measured by DT neutrons using two sets of lithium glass detectors with different thicknesses in the hole in the vertical direction with respect to the D+ beam of the Cockcroft-Walton neutron generator in direct current mode. The measured TPR distribution is compared with the calculated results obtained by the three-dimensional Monte Carlo code MCNP5 and the ENDF/B-VI data file. The discrepancy between the measured and calculated values can be attributed to the neutron data library of the hydrogen lithium lack S(α, β) thermal scattering model, so we show that a special database of low-energy and thermal neutrons should be established in the physics design of fusion-fission hybrid reactors.

  3. Heat losses in a CVD reactor for polysilicon production: Comprehensive model and experimental validation

    NASA Astrophysics Data System (ADS)

    Ramos, A.; Rodríguez, A.; del Cañizo, C.; Valdehita, J.; Zamorano, J. C.; Luque, A.

    2014-09-01

    This work addresses heat losses in a CVD reactor for polysilicon production. Contributions to the energy consumption of the so-called Siemens process are evaluated, and a comprehensive model for heat loss is presented. A previously-developed model for radiative heat loss is combined with conductive heat loss theory and a new model for convective heat loss. Theoretical calculations are developed and theoretical energy consumption of the polysilicon deposition process is obtained. The model is validated by comparison with experimental results obtained using a laboratory-scale CVD reactor. Finally, the model is used to calculate heat consumption in a 36-rod industrial reactor; the energy consumption due to convective heat loss per kilogram of polysilicon produced is calculated to be 22-30 kWh/kg along a deposition process.

  4. Multipurpose Small Size Fast Reactor: Its Basic Concept and Application to Nuclear Hydrogen Production

    SciTech Connect

    Endo, H.; Sawada, T.; Ninokata, H.

    2002-07-01

    Here we propose a basic concept of a multipurpose small-sized fast reactor and its applicability to produce nuclear hydrogen for near future mass use of hydrogen industrial and public use. The modular-type fast reactor of 150 MW thermal output does not require fuel exchange nor decommissioning on the site, and can be transported from the factory in a fabricated form. For the hydrogen production, we propose to use the sorption enhanced reforming process (SERP), in which the steam-methane reforming can take place around 450 - 550. Since this temperature range is rather low compared to the ongoing steam reforming method (> 800 ), the SERP system combined with an adequate nuclear reactor system should be a promising one to cope with the coming age of hydrogen civilization. (authors)

  5. A model for cellulase production from Trichoderma reesei in an airlift reactor.

    PubMed

    Bannari, Rachid; Bannari, Abdelfettah; Vermette, Patrick; Proulx, Pierre

    2012-08-01

    A mathematical model for cellulase production by Trichoderma reesei RUT-C30 grown in a cellulose medium with lactose as fed batch in an airlift reactor is proposed. To describe adequately the mass transfer between the air bubbles and the broth, it uses computational fluid dynamics (CFD) including multiphase Eulerian-Eulerian formulation, with a detailed description of the bubble size distribution through the use of the population balance model (PBM) and the class method (CM). The kinetics of the biomass growth is further coupled to the fluid flow conditions using partial differential equations for all the species involved, providing detailed information of important reactor conditions such as the distribution of oxygen, cellulose, and the shear stress within the reactor over the entire period of fermentation. Predicted results agree well with the available overall measurements for a typical fed-batch operation and detailed profiles of the predicted concentration fields are discussed from an engineering viewpoint. PMID:22389072

  6. Hydrocracking process with integrated distillate product hydrogenation reactor

    SciTech Connect

    Hoehn, R.K.; Reno, M.E.

    1991-06-25

    This patent describes a hydrocracking process. It comprises passing a feed stream which comprises an admixture of hydrocarbons boiling above 240 degrees Centigrade and hydrogen through a hydrocracking reaction zone maintained at hydrocracking conditions and producing a mixed-phase hydrocracking reaction zone effluent stream; separating the mixed-phase hydrocracking reaction zone effluent stream into a first vapor stream, which comprises hydrogen, light hydrocarbons and distillate hydrocarbons, and a first liquid stream, which comprises distillate hydrocarbons; forming a second vapor stream and a second liquid, stream by partially condensing the first vapor stream, with the second liquid stream comprising distillate hydrocarbons and having a lower average boiling point than the first liquid stream; passing the second liquid stream and added hydrogen through a hydrogenation reaction zone maintained at hydrogenation conditions and producing a hydrogenation zone effluent stream; and, passing distillate hydrocarbons present in the hydrogenation zone effluent stream and the first liquid stream into a fractionation zone, and recovering a hydrocracking zone product stream.

  7. Fission products from the damaged Fukushima reactor observed in Hungary.

    PubMed

    Bihari, Árpád; Dezső, Zoltán; Bujtás, Tibor; Manga, László; Lencsés, András; Dombóvári, Péter; Csige, István; Ranga, Tibor; Mogyorósi, Magdolna; Veres, Mihály

    2014-01-01

    Fission products, especially (131)I, (134)Cs and (137)Cs, from the damaged Fukushima Dai-ichi nuclear power plant (NPP) were detected in many places worldwide shortly after the accident caused by natural disaster. To observe the spatial and temporal variation of these isotopes in Hungary, aerosol samples were collected at five locations from late March to early May 2011: Institute of Nuclear Research, Hungarian Academy of Sciences (ATOMKI, Debrecen, East Hungary), Paks NPP (Paks, South-Central Hungary) as well as at the vicinity of Aggtelek (Northeast Hungary), Tapolca (West Hungary) and Bátaapáti (Southwest Hungary) settlements. In addition to the aerosol samples, dry/wet fallout samples were collected at ATOMKI, and airborne elemental iodine and organic iodide samples were collected at Paks NPP. The peak in the activity concentration of airborne (131)I was observed around 30 March (1-3 mBq m(-3) both in aerosol samples and gaseous iodine traps) with a slow decline afterwards. Aerosol samples of several hundred cubic metres of air showed (134)Cs and (137)Cs in detectable amounts along with (131)I. The decay-corrected inventory of (131)I fallout at ATOMKI was 2.1±0.1 Bq m(-2) at maximum in the observation period. Dose-rate contribution calculations show that the radiological impact of this event at Hungarian locations was of no considerable concern. PMID:24437973

  8. Environmental Assessment: Waste Tank Safety Program, Hanford Site, Richland, Washington

    SciTech Connect

    Not Available

    1994-02-01

    The US Department of Energy (DOE) needs to take action in the near-term, to accelerate resolution of waste tank safety issues at the Hanford Site near the City of Richland, Washington, and reduce the risks associated with operations and management of the waste tanks. The DOE has conducted nuclear waste management operations at the Hanford Site for nearly 50 years. Operations have included storage of high-level nuclear waste in 177 underground storage tanks (UST), both in single-shell tank (SST) and double-shell tank configurations. Many of the tanks, and the equipment needed to operate them, are deteriorated. Sixty-seven SSTs are presumed to have leaked a total approximately 3,800,000 liters (1 million gallons) of radioactive waste to the soil. Safety issues associated with the waste have been identified, and include (1) flammable gas generation and episodic release; (2) ferrocyanide-containing wastes; (3) a floating organic solvent layer in Tank 241-C-103; (4) nuclear criticality; (5) toxic vapors; (6) infrastructure upgrades; and (7) interim stabilization of SSTs. Initial actions have been taken in all of these areas; however, much work remains before a full understanding of the tank waste behavior is achieved. The DOE needs to accelerate the resolution of tank safety concerns to reduce the risk of an unanticipated radioactive or chemical release to the environment, while continuing to manage the wastes safely.

  9. Radioisotope research, production, and processing at the University of Missouri Research Reactor

    SciTech Connect

    Ehrhardt, G.J.; Ketring, A.R.; Ja, Wei; Ma, D.; Zinn, K.; Lanigan, J.

    1995-12-31

    The University of Missouri Research Reactor (MURR) is a 10 MW, light-water-cooled and moderated research reactor which first achieved criticality in 1996 and is currently the highest powered university-owned research reactor in the U.S. For many years a major supplier of reactor-produced isotopes for research and commercial purposes, in the last 15 years MURR has concentrated on development of reactor-produced beta-particle emitters for experimental use in nuclear medicine therapy of cancer and rheumatoid arthritis. MURR has played a major role in the development of bone cancer pain palliation with the agents {sup 153}Sm EDTMP and {sup 186}Re/{sup 188}Re HEDP, as well as in the use of {sup 186}Re, {sup 177}Lu, {sup 166}Ho, and {sup 105}Rh for radioimmunotherapy and receptor-agent-guided radiotherapy. MURR is also responsible for the development of therapeutic, {sup 90}Y-labeled glass microspheres for the treatment of liver tumors, a product ({sup 90}Y Therasphere{trademark}) which is currently an approved drug in Canada. MURR has also pioneered the development of {sup 188}W/{sup 188}Re and {sup 99}Mo/{sup 99m}Tc gel generators, which make the use of low specific activity {sup 188}W and {sup 99}Mo practical for such isotope generators.

  10. Biodiesel production from palm oil using combined mechanical stirred and ultrasonic reactor.

    PubMed

    Choedkiatsakul, I; Ngaosuwan, K; Cravotto, G; Assabumrungrat, S

    2014-07-01

    This paper investigates the production of biodiesel from palm oil using a combined mechanical stirred and ultrasonic reactor (MS-US). The incorporation of mechanical stirring into the ultrasonic reactor explored the further improvement the transesterification of palm oil. Initial reaction rate values were 54.1, 142.9 and 164.2 mmol/L min for the mechanical-stirred (MS), ultrasonic (US) and MS-US reactors, respectively. Suitable methanol to oil molar ratio and the catalyst loading values were found to be 6 and 1 of oil, respectively. The effect of ultrasonic operating parameters; i.e. frequency, location, and number of transducer, has been investigated. Based on the conversion yield at the reactor outlet after 1 h, the number of transducers showed a relevant role in the reaction rate. Frequency and transducer location would appear to have no significant effect. The properties of the obtained biodiesel (density, viscosity, pour point, and flash point) satisfy the ASTM standard. The combined MS-US reactors improved the reaction rate affording the methyl esters in higher yield. PMID:24418101

  11. Report on inspection of the performance based incentive program at the Richland Operations Office

    SciTech Connect

    1997-03-10

    The Fiscal Year (FY) 1995 Performance Based Incentive (PBI) Program at the Department of Energy`s (DOE) Richland Operations Office (Richland) was initiated by Richland as one part of the broader DOE Contract Reform Initiative being implemented at the Hanford Site in FY 1995. This program was identified as an area of concern by the Office of Inspections as a result of previous inspection work. Specifically, during a limited review of the construction of an Effluent Treatment Facility at the Hanford Site, we were unable to identify any written policies describing PBI program controls or implementation procedures. We were told that Richland Operations Office Program Management personnel were not directly involved in the selection of the Effluent Treatment Facility project for the PBI Program, or in the determination that this particular PBI would be established with a potential fee of $1 million.

  12. Reactor

    DOEpatents

    Evans, Robert M.

    1976-10-05

    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  13. Cephalosporin C production by a highly productive Cephalosporium acremonium strain in an airlift tower loop reactor with static mixers.

    PubMed

    Zhou, W; Holzhauer-Rieger, K; Bayer, T; Schgerl, K

    1993-04-01

    The production of cephalosporin C (CPC) and its precursors penicillin N (PEN N), deacetoxycephalosporin C (DAOC) and deacetylcephalosporin C (DAC), with a highly productive strain of Cephalosporin acremonium, was investigated in an 80-1 airlift tower loop reactor with four static mixer modules (Type SMV, Sulzer) (ATLRM) on a complex medium containing 50 g l-1 peanut flour (PF). The most important key parameters such as glucose concentration and cell mass concentration were monitored during a fed-batch cultivation process. The concentrations of products CPC, PEN N, DAOC an DAC were determined on line by HPLC. The influences of four motionless mixers on the dissolved oxygen concentration (DOC), oxygen transfer rate, the cell growth and the CPC production, as well as the reactor performance, were evaluated. The results were compared with the performance of an airlift tower loop reactor (ATLR) without static mixers as well as with a stirred tank reactor (STR). A comparison of cultivations in the ATLRM and ATLR with 50 g l-1 PF indicates that the obtained maximal CPC concentration and the (CPC + DAC + DAOC) concentration were 7% and 22% higher in the ATLRM (4.96 and 7.46 g l-1) than in the ATLR (4.63 and 6.13 g l-1) respectively. The maximal CPC volumetric productivity in the ATLRM (55.1 mg l-1 h-1) was also considerably higher than that in the ATLR (48.5 mg l-1 h-1). The specific power input was reduced from 2.36 to 1.5 kW m-3, the specific productivity pertaining to the power input was improved from 1.96 to 3.31 g W-1. On the other hand, cultivation in the ATLRM had a lower maximum CPC concentration and volumetric productivity than those in STR (7.2 g l-1 and 71.2 mg l-1 h-1) with the same medium due to the lower shear stress levels and the lower specific power input (1.5 vs. 3.0 kW m-3); but the specific power imput-based yield coefficient was in the ATLRM (3.31 g W-1) higher than in the STR (2.40 g W-1). By increasing the amount of PF, it was possible to enhance the CPC concentration and volumetric productivity in the STR. However, the performance of the ATLRM was limited to using a medium containing maximal 50 g l-1 PF because of the high viscosity of the medium, the limited energy input and thus the limited oxygen supply. PMID:7763560

  14. Knowledges and abilities catalog for nuclear power plant operators: Savannah River Site (SRS) production reactors

    SciTech Connect

    Not Available

    1990-06-20

    The Knowledges and Abilities Catalog for Nuclear Power Plant Operations: Savannah River Site (SRS) Production Reactors, provides the basis for the development of content-valid certification examinations for Senior Reactor Operators (SROs) and Central Control Room Supervisors (SUP). The position of Shift Technical Engineer (STE) has been included in the catalog for completeness. This new SRS reactor operating shift crew position is held by an individual holding a CCR Supervisor Certification who has received special engineering and technical training. Also, the STE has a Bachelor of Science degree in engineering or a related technical field. The SRS catalog contains approximately 2500 knowledge and ability (K/A) statements for SROs and SUPs at heavy water moderated production reactors. Each K/A statement has been rated for its importance to the safe operation of the plant in a manner ensuring the health and safety of the public. The SRS K/A catalog is presently organized into five major sections: Plant Systems grouped by Safety Function, Plant Wide Generic K/As, Emergency Plant Evolutions, Theory and Components (to be developed).

  15. Materials experience and selection for nuclear materials production reactor heat exchangers

    SciTech Connect

    Marra, J.E.; Louthan, M.R. Jr.

    1990-01-01

    The primary coolant systems for the heavy-water nuclear materials production reactors at the Savannah River Site are coupled to the secondary coolant systems through shell and tube heat exchangers. The head, shell, and tube sheets of these heat exchangers are fabricated from AISI Type 304 grades of austenitic stainless steel. The 8,957 tubes in each heat exchanger were originally fabricated from Type 304 stainless steel, but service experience has lead to the use of Sea Cure tubing in newer systems. The design includes double tube sheets, core rods, and 33,410 square feet of heat transfer surface. Tubes are rolled into the tube sheets and seal welded after rolling. The tubes contain Type 304 stainless steel rods which are positioned in the center of each tube axis to increase the fraction of the cooling water contacting the heat transfer surface. Each reactor utilizes twelve heat exchangers; thus the 120+ reactor-years of operating experience provide approximately 1,440 heat exchanger-years of service. Fatigue, stress corrosion cracking, crevice corrosion, and pitting have been observed during the service life. This paper describes the observed degradation processes and uses the operational experience to recommend materials for the Heavy Water -- New Production Reactor (HW-NPR).

  16. Technical assumption for Mo-99 production in the MARIA reactor. Feasibility study

    SciTech Connect

    Jaroszewicz, J.; Pytel, K.; Dabkowski, L.; Krzysztoszek, G.

    2008-07-15

    The main objective of U-235 irradiation is to obtain the Tc-99m isotope which is widely used in the domain of medical diagnostics. The decisive factor determining its availability, despite its short life time, is a reaction of radioactive decay of Mo-99 into Tc- 99m. One of the possible sources of molybdenum can be achieved in course of the U-235 fission reaction. The paper presents activities and the calculations results obtained upon the feasibility study on irradiation of U-235 targets for production of molybdenum in the MARIA reactor. The activities including technical assumption were focused on performing calculation for modelling of the target and irradiation device as well as adequate equipment and tools for processing in reactor. It has been assumed that the basic component of fuel charge is an aluminium cladded plate with dimensions of 40x230x1.45 containing 4.7 g U-235. The presumed mode of the heat removal generated in the fuel charge of the reactor primary cooling circuit influences the construction of installation to be used for irradiation and the technological instrumentation. The outer channel construction for irradiation has to be identical as the standard fuel channel construction of the MARIA reactor. It enables to use the existing slab and reactor mounting sockets for the fastening of the molybdenum channel as well as the cooling water delivery system. The measurement of water temperature cooling a fuel charge and control of water flow rate in the channel can also be carried out be means of the standard instrumentation of the reactor. (author)

  17. Methane production by treating vinasses from hydrous ethanol using a modified UASB reactor

    PubMed Central

    2012-01-01

    Background A modified laboratory-scale upflow anaerobic sludge blanket (UASB) reactor was used to obtain methane by treating hydrous ethanol vinasse. Vinasses or stillage are waste materials with high organic loads, and a complex composition resulting from the process of alcohol distillation. They must initially be treated with anaerobic processes due to their high organic loads. Vinasses can be considered multipurpose waste for energy recovery and once treated they can be used in agriculture without the risk of polluting soil, underground water or crops. In this sense, treatment of vinasse combines the elimination of organic waste with the formation of methane. Biogas is considered as a promising renewable energy source. The aim of this study was to determine the optimum organic loading rate for operating a modified UASB reactor to treat vinasse generated in the production of hydrous ethanol from sugar cane molasses. Results The study showed that chemical oxygen demand (COD) removal efficiency was 69% at an optimum organic loading rate (OLR) of 17.05 kg COD/m3-day, achieving a methane yield of 0.263 m3/kg CODadded and a biogas methane content of 84%. During this stage, effluent characterization presented lower values than the vinasse, except for potassium, sulfide and ammonia nitrogen. On the other hand, primers used to amplify the 16S-rDNA genes for the domains Archaea and Bacteria showed the presence of microorganisms which favor methane production at the optimum organic loading rate. Conclusions The modified UASB reactor proposed in this study provided a successful treatment of the vinasse obtained from hydrous ethanol production. Methanogen groups (Methanobacteriales and Methanosarcinales) detected by PCR during operational optimum OLR of the modified UASB reactor, favored methane production. PMID:23167984

  18. Simultaneous saccharification and fermentation of starch for ethanol production in a fluidized-bed reactor

    SciTech Connect

    Nghiem, N.P.; Davison, B.H.; Sun, M.Y.; Bienkowski, P.R.

    1997-12-31

    Immobilized Zymomonas mobilis has been used to produce ethanol from glucose in fluidized-bed reactor at volumetric productivity as high as 60 g/L-h and theoretical yield. This research was extended to study the production of ethanol from starch. The bacteria were co-immobilized with an industrial glucoamylase within small uniform beads (2 to 2.5 mm diameter) of k-carrageenan. The reactor was a glass column of 1.2 m in length with a uniform 2.54 cm diameter. The substrate included a commercially available maltodextrin and a soluble starch solution which was produced by hydrolysis of ground corn meals using amylase under the conditions commonly used in an industrial process. Light steep water was used as the complex nutrient source. Statistical experimental design was used to study the effects of substrate concentration and feed rate on ethanol yield and reactor productivity. The experiments were performed at 30{degrees}C and pH 5. The substrate concentration ranged from 93 to 2.7 g/L and the feed rates from 6.6 to 26.7 mL/min. The results of these studies will be discussed.

  19. Fuel and core testing plan for a target fueled isotope production reactor.

    SciTech Connect

    Coats, Richard Lee; Dahl, James J.; Parma, Edward J., Jr.

    2010-12-01

    In recent years there has been an unstable supply of the critical diagnostic medical isotope 99Tc. Several concepts and designs have been proposed to produce 99Mo the parent nuclide of 99Tc, at a commercial scale sufficient to stabilize the world supply. This work lays out a testing and experiment plan for a proposed 2 MW open pool reactor fueled by Low Enriched Uranium (LEU) 99Mo targets. The experiments and tests necessary to support licensing of the reactor design are described and how these experiments and tests will help establish the safe operating envelop for a medical isotope production reactor is discussed. The experiments and tests will facilitate a focused and efficient licensing process in order to bring on line a needed production reactor dedicated to supplying medical isotopes. The Target Fuel Isotope Reactor (TFIR) design calls for an active core region that is approximately 40 cm in diameter and 40 cm in fuel height. It contains up to 150 cylindrical, 1-cm diameter, LEU oxide fuel pins clad with Zircaloy (zirconium alloy), in an annular hexagonal array on a {approx}2.0 cm pitch surrounded, radially, by a graphite or a Be reflector. The reactor is similar to U.S. university reactors in power, hardware, and safety/control systems. Fuel/target pin fabrication is based on existing light water reactor fuel fabrication processes. However, as part of licensing process, experiments must be conducted to confirm analytical predictions of steady-state power and accident conditions. The experiment and test plan will be conducted in phases and will utilize existing facilities at the U.S. Department of Energy's Sandia National Laboratories. The first phase is to validate the predicted reactor core neutronics at delayed critical, zero power and very low power. This will be accomplished by using the Sandia Critical Experiment (CX) platform. A full scale TFIR core will be built in the CX and delayed critical measurements will be taken. For low power experiments, fuel pins can be removed after the experiment and using Sandia's metrology lab, relative power profiles (radially and axially) can be determined. In addition to validating neutronic analyses, confirming heat transfer properties of the target/fuel pins and core will be conducted. Fuel/target pin power limits can be verified with out-of-pile (electrical heating) thermal-hydraulic experiments. This will yield data on the heat flux across the Zircaloy clad and establish safety margin and operating limits. Using Sandia's Annular Core Research Reactor (ACRR) a 4 MW TRIGA type research reactor, target/fuel pins can be driven to desired fission power levels for long durations. Post experiment inspection of the pins can be conducted in the Auxiliary Hot Cell Facility to observe changes in the mechanical properties of the LEU matrix and burn-up effects. Transient tests can also be conducted at the ACRR to observe target/fuel pin performance during accident conditions. Target/fuel pins will be placed in double experiment containment and driven by pulsing the ACRR until target/fuel failure is observed. This will allow for extrapolation of analytical work to confirm safety margins.

  20. Economic Analysis of a Nuclear Reactor Powered High-Temperature Electrolysis Hydrogen Production Plant

    SciTech Connect

    E. A. Harvego; M. G. McKellar; M. S. Sohal; J. E. O'Brien; J. S. Herring

    2008-08-01

    A reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production was developed to provide a basis for comparing the HTE concept with other hydrogen production concepts. The reference plant design is driven by a high-temperature helium-cooled nuclear reactor coupled to a direct Brayton power cycle. The reference design reactor power is 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 540°C and 900°C, respectively. The electrolysis unit used to produce hydrogen includes 4,009,177 cells with a per-cell active area of 225 cm2. The optimized design for the reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes an air-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The inlet air for the air-sweep system is compressed to the system operating pressure of 5.0 MPa in a four-stage compressor with intercooling. The alternating-current, AC, to direct-current, DC, conversion efficiency is 96%. The overall system thermal-to-hydrogen production efficiency (based on the lower heating value of the produced hydrogen) is 47.12% at a hydrogen production rate of 2.356 kg/s. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.23/kg of hydrogen was calculated assuming an internal rate of return of 10%.

  1. Production of the Anticarsia gemmatalis multiple nucleopolyhedrovirus in serum-free suspension cultures of the saUFL-AG-286 cell line in stirred reactor and airlift reactor.

    PubMed

    Micheloud, Gabriela A; Gioria, Verónica V; Eberhardt, Ignacio; Visnovsky, Gabriel; Claus, Juan D

    2011-12-01

    The velvetbean caterpillar, Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae), is one of the main plagues for soybean crops. Velvetbean caterpillar larvae are susceptible to be infected by occlusion bodies of the baculovirus Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV), a biological insecticide. The insect cell line saUFL-AG-286 produces very high yields of occlusion bodies of AgMNPV in suspension cultures done in the low-cost serum-free medium UNL-10 in shake-flasks. However, its ability to adapt to conditions of industrial production in bioreactors was unknown. The aim of this study was to characterize the growth of saUFL-AG-286 cell cultures in UNL-10 medium, as well as its capability to replicate AgMNPV in two different bio-reactors at laboratory scale. The cell line was able to adapt to conditions that can be used at industrial scale, both in an airlift reactor and a stirred reactor, although the former was better than the last to support the cell growth. The infection with AgMNPV in the airlift reactor produced a high yield of occlusion bodies, with very low production of budded virus, the progeny used as inoculums. On the other hand, infection in the stirred reactor yielded high titers of budded virus. These results suggest that a feasible strategy for scaling-up the production of AgMNPV might involve the use of airlift reactors for the scaling-up of cell suspension cultures and the final production of occlusion bodies, while the scaling-up of the viral inoculums being carried out under conditions as those existing in stirred reactors. PMID:21906626

  2. Accelerator-Reactor Coupling for Energy Production in Advanced Nuclear Fuel Cycles

    NASA Astrophysics Data System (ADS)

    Heidet, Florent; Brown, Nicholas R.; Tahar, Malek Haj

    This article is a review of several accelerator-reactor interface issues and nuclear fuel cycle applications of accelerator-driven subcritical systems. The systems considered here have the primary goal of energy production, but that goal is accomplished via a specific application in various proposed nuclear fuel cycles, such as breed-and-burn of fertile material or burning of transuranic material. Several basic principles are reviewed, starting from the proton beam window including the target, blanket, reactor core, and up to the fuel cycle. We focus on issues of interest, such as the impact of the energy required to run the accelerator and associated systems on the potential electricity delivered to the grid. Accelerator-driven systems feature many of the constraints and issues associated with critical reactors, with the added challenges of subcritical operation and coupling to an accelerator. Reliable accelerator operation and avoidance of beam trips are critically important. One interesting challenge is measurement of blanket subcriticality level during operation. We also review the potential benefits of accelerator-driven systems in various nuclear fuel cycle applications. Ultimately, accelerator-driven subcritical systems with the goal of transmutation of transuranic material have lower 100,000-year radioactivity than a critical fast reactor with recycling of uranium and plutonium.

  3. Modeling of the HiPco process for carbon nanotube production. II. Reactor-scale analysis

    NASA Technical Reports Server (NTRS)

    Gokcen, Tahir; Dateo, Christopher E.; Meyyappan, M.

    2002-01-01

    The high-pressure carbon monoxide (HiPco) process, developed at Rice University, has been reported to produce single-walled carbon nanotubes from gas-phase reactions of iron carbonyl in carbon monoxide at high pressures (10-100 atm). Computational modeling is used here to develop an understanding of the HiPco process. A detailed kinetic model of the HiPco process that includes of the precursor, decomposition metal cluster formation and growth, and carbon nanotube growth was developed in the previous article (Part I). Decomposition of precursor molecules is necessary to initiate metal cluster formation. The metal clusters serve as catalysts for carbon nanotube growth. The diameter of metal clusters and number of atoms in these clusters are some of the essential information for predicting carbon nanotube formation and growth, which is then modeled by the Boudouard reaction with metal catalysts. Based on the detailed model simulations, a reduced kinetic model was also developed in Part I for use in reactor-scale flowfield calculations. Here this reduced kinetic model is integrated with a two-dimensional axisymmetric reactor flow model to predict reactor performance. Carbon nanotube growth is examined with respect to several process variables (peripheral jet temperature, reactor pressure, and Fe(CO)5 concentration) with the use of the axisymmetric model, and the computed results are compared with existing experimental data. The model yields most of the qualitative trends observed in the experiments and helps to understanding the fundamental processes in HiPco carbon nanotube production.

  4. Fast subcritical hybrid reactors for energy production: evolution of physical parameters and induced radiotoxicities

    NASA Astrophysics Data System (ADS)

    David, S.; Billebaud, A.; Brandan, M. E.; Brissot, R.; Giorni, A.; Heuer, D.; Loiseaux, J.-M.; Méplan, O.; Nifenecker, H.; Viano, J.-B.; Schapira, J.-P.

    2000-04-01

    We have performed detailed Monte Carlo simulations of different subcritical fast hybrid reactor fuel configurations leading to the possible use of these devices as energy generators. The method is based on the coupling between a validated neutron transport code and a mathematical solution of the equations describing the time evolution of the neutron spectrum and mean cross-section during the reactor operation. We have optimized the geometrical and operational characteristics of reactors based on 232Th/ 233U and natU/Pu oxide fuels and simulated their operation over 20 fuel cycles (200 years of energy generation). Quantitative results are presented for the inventories, waste production and induced radiotoxicities under alternative scenarios of fuel reprocessing. The possible paths to start a fuel cycle based on thorium are studied, identifying the use of highly enriched uranium or plutonium from PWR spent fuel as options to start a fuel cycle which tends asymptotically towards 232Th/ 233U. The comparison between the simulated hybrid systems and the existing PWR reactors indicate significant reductions of the total radiotoxicity for fuel cycles based on thorium and fuel reprocessing which include the minor actinides, as well as plutonium and uranium separation.

  5. Modeling and static optimization of the ethanol production in a cascade reactor. I. Modeling

    SciTech Connect

    Dourado, A; Goma, G.; Albuquerque, U.; Sevely, Y.

    1987-02-05

    Let us consider the modeling of a cascade reactor for the production of ethanol. The rates of reaction in alcoholic fermentation are modeled so that it can assume both ethanol and substrate inhibition, in relation to the observed results. A nonstructured model, based on biomass, substrate, and ethanol concentrations, is developed and identified. It is a complex model, this being due to the nonlinearity between the specific rate of ethanol production and the growth rate, on the other hand, the study of the static optimization of ethanol fermentation is performed. 20 references.

  6. A review of existing gas-cooled reactor circulators with application of the lessons learned to the new production reactor circulators

    SciTech Connect

    White, L.S.

    1990-07-01

    This report presents the results of a study of the lessons learned during the design, testing, and operation of gas-cooled reactor coolant circulators. The intent of this study is to identify failure modes and problem areas of the existing circulators so this information can be incorporated into the design of the circulators for the New Production Reactor (NPR)-Modular High-Temperature Gas Cooled Reactor (MHTGR). The information for this study was obtained primarily from open literature and includes data on high-pressure, high-temperature helium test loop circulators as well as the existing gas cooled reactors worldwide. This investigation indicates that trouble free circulator performance can only be expected when the design program includes a comprehensive prototypical test program, with the results of this test program factored into the final circulator design. 43 refs., 7 tabs.

  7. Production of volatile fatty acids from wastewater screenings using a leach-bed reactor.

    PubMed

    Cadavid-Rodríguez, Luz Stella; Horan, Nigel J

    2014-09-01

    Screenings recovered from the inlet works of wastewater treatment plants were digested without pre-treatment or dilution using a lab-scale, leach-bed reactor. Variations in recirculation ratio of the leachate of 4 and 8 l/lreactor/day and pH values of 5 and 6 were evaluated in order to determine the optimal operating conditions for maximum total volatile fatty acids (VFA) production. By increasing the recirculation ratio of the leachate from 4 to 8 l/lreactor/day it was possible to increase VFA production (11%) and soluble COD (17%) and thus generate up to 264 g VFA/kg-dry screenings. These VFA were predominantly acetic acid with some propionic and butyric acid. The optimum pH for VFA production was 6.0, when the methanogenic phase was inhibited. Below pH 5.0, acid-producing fermentation was inhibited and some alcohols were produced. Ammonia release during the hydrolysis of screenings provided adequate alkalinity; consequently, a digestion process without pH adjustment could be recommended. The leach-bed reactor was able to achieve rapid rates of screenings degradation with the production of valuable end-products that will reduce the carbon footprint associated with current screenings disposal techniques. PMID:24862954

  8. Assessment of fission product yields data needs in nuclear reactor applications

    SciTech Connect

    Kern, K.; Becker, M.; Broeders, C.

    2012-07-01

    Studies on the build-up of fission products in fast reactors have been performed, with particular emphasis on the effects related to the physics of the nuclear fission process. Fission product yields, which are required for burn-up calculations, depend on the proton and neutron number of the target nucleus as well as on the incident neutron energy. Evaluated nuclear data on fission product yields are available for all relevant target nuclides in reactor applications. However, the description of their energy dependence in evaluated data is still rather rudimentary, which is due to the lack of experimental fast fission data and reliable physical models. Additionally, physics studies of evaluated JEFF-3.1.1 fission yields data have shown potential improvements, especially for various fast fission data sets of this evaluation. In recent years, important progress in the understanding of the fission process has been made, and advanced model codes are currently being developed. This paper deals with the semi-empirical approach to the description of the fission process, which is used in the GEF code being developed by K.-H. Schmidt and B. Jurado on behalf of the OECD Nuclear Energy Agency, and with results from the corresponding author's diploma thesis. An extended version of the GEF code, supporting the calculation of spectrum weighted fission product yields, has been developed. It has been applied to the calculation of fission product yields in the fission rate spectra of a MOX fuelled sodium-cooled fast reactor. Important results are compared to JEFF-3.1.1 data and discussed in this paper. (authors)

  9. An analytical assessment of the chemical form of fission products during postulated severe accidents in the SRS production reactors

    SciTech Connect

    Adams, J.P.

    1991-01-01

    An analysis has been performed to determine the principal chemical forms for the structural and fission product elements during a postulated severe core damage accident in tritium powered core in the Savannah River Site (SRS) reactors. These reactors are powered with UAl{sub x} fuel and are used for the production of weapons materials. Six core elements, cesium, iodine, tellurium, strontium, barium, and lithium, were emphasized in this analysis. Other elements also included were aluminum, hydrogen, oxygen, uranium, molybdenum, silicon, zirconium, magnesium, iron, chromium, nickel, cadmium, zinc, cooper, manganese, nitrogen, and argon. The masses of each of the constituents used in the analyses were based on end-or-core life masses for the structural and fission product elements and on core gas volume for steam, N, and Ar. A chemical equilibrium analysis was performed using the Facility for Analysis of Chemical Thermodynamics (FACT) computer code at three temperatures (800, 1100, 1400 K) and two pressures (1 and 10 atmospheres). These temperatures and pressures are typical for postulated severe core accidents in the ATR.

  10. An analytical assessment of the chemical form of fission products during postulated severe accidents in the SRS production reactors

    SciTech Connect

    Adams, J.P.

    1991-12-31

    An analysis has been performed to determine the principal chemical forms for the structural and fission product elements during a postulated severe core damage accident in tritium powered core in the Savannah River Site (SRS) reactors. These reactors are powered with UAl{sub x} fuel and are used for the production of weapons materials. Six core elements, cesium, iodine, tellurium, strontium, barium, and lithium, were emphasized in this analysis. Other elements also included were aluminum, hydrogen, oxygen, uranium, molybdenum, silicon, zirconium, magnesium, iron, chromium, nickel, cadmium, zinc, cooper, manganese, nitrogen, and argon. The masses of each of the constituents used in the analyses were based on end-or-core life masses for the structural and fission product elements and on core gas volume for steam, N, and Ar. A chemical equilibrium analysis was performed using the Facility for Analysis of Chemical Thermodynamics (FACT) computer code at three temperatures (800, 1100, 1400 K) and two pressures (1 and 10 atmospheres). These temperatures and pressures are typical for postulated severe core accidents in the ATR.

  11. Modular Hybrid Plasma Reactor for Low Cost Bulk Production of Nanomaterials

    SciTech Connect

    Peter C. Kong

    2011-12-01

    INL developed a bench scale modular hybrid plasma system for gas phase nanomaterials synthesis. The system was being optimized for WO3 nanoparticles production and scale model projection to a 300 kW pilot system. During the course of technology development many modifications had been done to the system to resolve technical issues that had surfaced and also to improve the performance. All project tasks had been completed except 2 optimization subtasks. These 2 subtasks, a 4-hour and an 8-hour continuous powder production runs at 1 lb/hr powder feeding rate, were unable to complete due to technical issues developed with the reactor system. The 4-hour run had been attempted twice and both times the run was terminated prematurely. The modular electrode for the plasma system was significantly redesigned to address the technical issues. Fabrication of the redesigned modular electrodes and additional components had been completed at the end of the project life. However, not enough resource was available to perform tests to evaluate the performance of the new modifications. More development work would be needed to resolve these problems prior to scaling. The technology demonstrated a surprising capability of synthesizing a single phase of meta-stable delta-Al2O3 from pure alpha-phase large Al2O3 powder. The formation of delta-Al2O3 was surprising because this phase is meta-stable and only formed between 973-1073 K, and delta-Al2O3 is very difficult to synthesize as a single phase. Besides the specific temperature window to form this phase, this meta-stable phase may have been stabilized by nanoparticle size formed in a high temperature plasma process. This technology may possess the capability to produce unusual meta-stable nanophase materials that would be otherwise difficult to produce by conventional methods. A 300 kW INL modular hybrid plasma pilot scale model reactor had been projected using the experimental data from PPG Industries 300 kW hot wall plasma reactor. The projected size of the INL 300 kW pilot model reactor would be about 15% that of the PPG 300 kW hot wall plasma reactor. Including the safety net factor the projected INL pilot reactor size would be 25-30% of the PPG 300 kW hot wall plasma pilot reactor. Due to the modularity of the INL plasma reactor and the energy cascading effect from the upstream plasma to the downstream plasma the energy utilization is more efficient in material processing. It is envisioning that the material through put range for the INL pilot reactor would be comparable to the PPG 300 kW pilot reactor but the energy consumption would be lower. The INL hybrid plasma technology is rather close to being optimized for scaling to a pilot system. More near term development work is still needed to complete the process optimization before pilot scaling.

  12. An aerial radiological survey of the Hanford Site and surrounding area, Richland, Washington

    SciTech Connect

    Not Available

    1990-10-01

    An aerial radiological survey was conducted over the Department of Energy's Hanford Site near Richland, Washington, during the period 5 July through 26 August 1988. The survey was expanded, and additional flights were conducted to the east of the site and along the banks of the Columbia River down to McNary Dam near Umatilla. The survey was flown at altitude of 61 meters (200 feet) by a helicopter containing 17 liters (eight 2 in. {times} 4 in. {times} 16 in.) of sodium iodide detectors. Gamma ray data were collected over the survey area by flying north-south lines spaced 122 meters (400 feet) apart. The processed data indicated that detected radioisotopes and their associated gamma ray exposure rates were generally consistent with those expected from normal background emitters and man-made fission/activation products resulting from activities at the site. External exposure rates were generally 10 microroentgens per hour ({mu}R/h) with some operating areas over 1000 {mu}R/h. The radiation levels over more than 95% of the site are due to normal background exposure rates. 3 refs., 25 figs.

  13. Production of polygalacturonases by Aspergillus oryzae in stirred tank and internal- and external-loop airlift reactors.

    PubMed

    Fontana, Roselei Claudete; da Silveira, Maurício Moura

    2012-11-01

    The production of endo- and exo-polygalacturonase (PG) by Aspergillus oryzae was assessed in stirred tank reactors (STRs), internal-loop airlift reactors (ILARs) and external-loop airlift reactors (ELARs). For STR production, we compared culture media formulated with either pectin (WBE) or partially hydrolyzed pectin. The highest enzyme activities were obtained in medium that contained 50% pectin in hydrolyzed form (WBE5). PG production in the three reactor types was compared for WBE5 and low salt WBE medium, with additional salts added at 48, 60 and 72h (WBES). The ELARs performed better than the ILARs in WBES medium where the exo-PG was the same concentration as for STRs and the endo-PG was 20% lower. These results indicate that PG production is higher under experimental conditions that result in higher cell growth with minimum pH values less than 3.0. PMID:22940313

  14. Non-catalytic alcoholysis process for production of biodiesel fuel by using bubble column reactor

    NASA Astrophysics Data System (ADS)

    Hagiwara, S.; Nabetani, H.; Nakajima, M.

    2015-04-01

    Biodiesel fuel is a replacement for diesel as a fuel produced from biomass resources. It is usually defined as a fatty acid methyl ester (FAME) derived from vegetable oil or animal fat. In European countries, such as Germany and France, biodiesel fuel is commercially produced mainly from rapeseed oil, whereas in the United States and Argentina, soybean oil is more frequently used. In many other countries such as Japan and countries in Southeast Asia, lipids that cannot be used as a food source could be more suitable materials for the production of biodiesel fuel because its production from edible oils could result in an increase in the price of edible oils, thereby increasing the cost of some foodstuffs. Therefore, used edible oil, lipids contained in waste effluent from the oil milling process, byproducts from oil refining process and crude oils from industrial crops such as jatropha could be more promising materials in these countries. The materials available in Japan and Southeast Asia for the production of biodiesel fuel have common characteristics; they contain considerable amount of impurities and are high in free fatty acids (FFA). Superheated methanol vapor (SMV) reactor might be a promising method for biodiesel fuel production utilizing oil feedstock containing FFA such as waste vegetable oil and crude vegetable oil. In the conventional method using alkaline catalyst, FFA contained in waste vegetable oil is known to react with alkaline catalyst such as NaOH and KOH generating saponification products and to inactivate it. Therefore, the FFA needs to be removed from the feedstock prior to the reaction. Removal of the alkaline catalyst after the reaction is also required. In the case of the SMV reactor, the processes for removing FFA prior to the reaction and catalyst after the reaction can be omitted because it requires no catalyst. Nevertheless, detailed study on the productivity of biodiesel fuel produced from waste vegetable oils and other non-edible lipids by use of the SMV reactor has not been examined yet. Therefore, this study aims to investigate the productivity of biodiesel produced from waste vegetable oils using the SMV reactor. Biodiesel fuel is a replacement for diesel as a fuel produced from biomass resources. It is generally produced as a FAME derived from vegetable oil by using alkaline catalyzed alcoholysis process. This alkaline method requires deacidification process prior to the reaction process and the alkaline catalyst removal process after the reaction. Those process increases the total cost of biodiesel fuel production. In order to solve the problems in the conventional alkaline catalyzed alcoholysis process, the authors proposed a non-catalytic alcoholysis process called the Superheated Methanol Vapor (SMV) method with bubble column reactor. So, this study aims to investigate the productivity of biodiesel produced from vegetable oils and other lipids using the SMV method with bubble column reactor.

  15. Butanol production by bioconversion of cheese whey in a continuous packed bed reactor.

    PubMed

    Raganati, F; Olivieri, G; Procentese, A; Russo, M E; Salatino, P; Marzocchella, A

    2013-06-01

    Butanol production by Clostridium acetobutylicum DSM 792 fermentation was investigated. Unsupplemented cheese whey was adopted as renewable feedstock. The conversion was successfully carried out in a biofilm packed bed reactor (PBR) for more than 3 months. The PBR was a 4 cm ID, 16 cm high glass tube with a 8 cm bed of 3mm Tygon rings, as carriers. It was operated at the dilution rate between 0.4h(-1) and 0.94 h(-1). The cheese whey conversion process was characterized in terms of metabolites production (butanol included), lactose conversion and biofilm mass. Under optimized conditions, the performances were: butanol productivity 2.66 g/Lh, butanol concentration 4.93 g/L, butanol yield 0.26 g/g, butanol selectivity of the overall solvents production 82 wt%. PMID:23619138

  16. Semicontinuous Production of Lactic Acid From Cheese Whey Using Integrated Membrane Reactor

    NASA Astrophysics Data System (ADS)

    Li, Yebo; Shahbazi, Abolghasem; Coulibaly, Sekou; Mims, Michele M.

    Semicontinuous production of lactic acid from cheese whey using free cells of Bifidobacterium longum with and without nanofiltration was studied. For the semicontinuous fermentation without membrane separation, the lactic acid productivity of the second and third runs is much lower than the first run. The semicontinuous fermentation with nanoseparation was run semicontinuously for 72 h with lactic acid to be harvested every 24 h using a nanofiltration membrane unit. The cells and unutilized lactose were kept in the reactor and mixed with newly added cheese whey in the subsequent runs. Slight increase in the lactic acid productivity was observed in the second and third runs during the semicontinuous fermentation with nanofiltration. It can be concluded that nanoseparation could improve the lactic acid productivity of the semicontinuous fermentation process.

  17. Feasibility study Part I - Thermal hydraulic analysis of LEU target for {sup 99}Mo production in Tajoura reactor

    SciTech Connect

    Bsebsu, F.M.; Abotweirat, F. E-mail: abutweirat@yahoo.com; Elwaer, S.

    2008-07-15

    The Renewable Energies and Water Desalination Research Center (REWDRC), Libya, will implement the technology for {sup 99}Mo isotope production using LEU foil target, to obtain new revenue streams for the Tajoura nuclear research reactor and desiring to serve the Libyan hospitals by providing the medical radioisotopes. Design information is presented for LEU target with irradiation device and irradiation Beryllium (Be) unit in the Tajoura reactor core. Calculated results for the reactor core with LEU target at different level of power are presented for steady state and several reactivity induced accident situations. This paper will present the steady state thermal hydraulic design and transient analysis of Tajoura reactor was loaded with LEU foil target for {sup 99}Mo production. The results of these calculations show that the reactor with LEU target during the several cases of transient are in safe and no problems will occur. (author)

  18. Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Dominques, Jesus A.

    2012-01-01

    The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates thermal energy that should be able to maintain the molten phase (similar to electrolytic Hall-Heroult process for aluminum production). Self-heating via Joule heating offers many advantages: (1) The regolith itself is the crucible material, it protects the vessel walls (2) Simplifies the engineering of the reactor (3) Reduces power consumption (no external heating) (4) Extends the longevity of the reactor. Predictive modeling is a tool chosen to perform dimensional analysis of a self-heating reactor: (1) Multiphysics modeling (COMSOL) was selected for Joule heat generation and heat transfer (2) Objective is to identify critical dimensions for first reactor prototype.

  19. Enhanced production of bacterial cellulose by using a biofilm reactor and its material property analysis

    PubMed Central

    Cheng, Kuan-Chen; Catchmark, Jeff M; Demirci, Ali

    2009-01-01

    Bacterial cellulose has been used in the food industry for applications such as low-calorie desserts, salads, and fabricated foods. It has also been used in the paper manufacturing industry to enhance paper strength, the electronics industry in acoustic diaphragms for audio speakers, the pharmaceutical industry as filtration membranes, and in the medical field as wound dressing and artificial skin material. In this study, different types of plastic composite support (PCS) were implemented separately within a fermentation medium in order to enhance bacterial cellulose (BC) production by Acetobacter xylinum. The optimal composition of nutritious compounds in PCS was chosen based on the amount of BC produced. The selected PCS was implemented within a bioreactor to examine the effects on BC production in a batch fermentation. The produced BC was analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). Among thirteen types of PCS, the type SFYR+ was selected as solid support for BC production by A. xylinum in a batch biofilm reactor due to its high nitrogen content, moderate nitrogen leaching rate, and sufficient biomass attached on PCS. The PCS biofilm reactor yielded BC production (7.05 g/L) that was 2.5-fold greater than the control (2.82 g/L). The XRD results indicated that the PCS-grown BC exhibited higher crystallinity (93%) and similar crystal size (5.2 nm) to the control. FESEM results showed the attachment of A. xylinum on PCS, producing an interweaving BC product. TGA results demonstrated that PCS-grown BC had about 95% water retention ability, which was lower than BC produced within suspended-cell reactor. PCS-grown BC also exhibited higher Tmax compared to the control. Finally, DMA results showed that BC from the PCS biofilm reactor increased its mechanical property values, i.e., stress at break and Young's modulus when compared to the control BC. The results clearly demonstrated that implementation of PCS within agitated fermentation enhanced BC production and improved its mechanical properties and thermal stability. PMID:19630969

  20. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    SciTech Connect

    Mahesh Iyer; Himanshu Gupta; Danny Wong; Liang-Shih Fan

    2005-09-30

    Hydrogen production from coal gasification can be enhanced by driving the equilibrium limited Water Gas Shift reaction forward by incessantly removing the CO{sub 2} by-product via the carbonation of calcium oxide. This project aims at using the OSU patented high-reactivity mesoporous precipitated calcium carbonate sorbent for removing the CO{sub 2} product. Preliminary experiments demonstrate the show the superior performance of the PCC sorbent over other naturally occurring calcium sorbents. Gas composition analyses show the formation of 100% pure hydrogen. Novel calcination techniques could lead to smaller reactor footprint and single-stage reactors that can achieve maximum theoretical H{sub 2} production for multicyclic applications. Sub-atmospheric calcination studies reveal the effect of vacuum level, diluent gas flow rate, thermal properties of the diluent gas and the sorbent loading on the calcination kinetics which play an important role on the sorbent morphology. Steam, which can be easily separated from CO{sub 2}, is envisioned to be a potential diluent gas due to its enhanced thermal properties. Steam calcination studies at 700-850 C reveal improved sorbent morphology over regular nitrogen calcination. A mixture of 80% steam and 20% CO{sub 2} at ambient pressure was used to calcine the spent sorbent at 820 C thus lowering the calcination temperature. Regeneration of calcium sulfide to calcium carbonate was achieved by carbonating the calcium sulfide slurry by bubbling CO{sub 2} gas at room temperature.

  1. Final Environmental Impact Statement for the Production of Tritium in a Commercial Light Water Reactor

    SciTech Connect

    N /A

    1999-03-12

    The U.S. Department of Energy (DOE) is responsible for providing the nation with nuclear weapons and ensuring that these weapons remain safe and reliable. Tritium, a radioactive isotope of hydrogen, is an essential component of every weapon in the current and projected U.S. nuclear weapons stockpile. Unlike other materials utilized in nuclear weapons, tritium decays at a rate of 5.5 percent per year. Accordingly, as long as the nation relies on a nuclear deterrent, the tritium in each nuclear weapon must be replenished periodically. Currently the U.S. nuclear weapons complex does not have the capability to produce the amounts of tritium that will be required to continue supporting the nation's stockpile. The ''Final Programmatic Environmental Impact Statement for Tritium Supply and Recycling'' (Final Programmatic EIS), DOE/EIS-0161, issued in October 1995, evaluated the alternatives for the siting, construction, and operation of tritium supply and recycling facilities at five DOE sites for four different production technologies. This Programmatic EIS also evaluated the impacts of using a commercial light water reactor (CLWR) without specifying a reactor location. In the Record of Decision for the Final Programmatic EIS (60 FR 63878), issued December 12, 1995, DOE decided to pursue a dual-track approach on the two most promising tritium supply alternatives: (1) to initiate purchase of an existing commercial reactor (operating or partially complete) or reactor irradiation services; and (2) to design, build, and test critical components of an accelerator system for tritium production. At that time, DOE announced that the final decision would be made by the Secretary of Energy at the end of 1998.

  2. Analysis of the magnetic corrosion product deposits on a boiling water reactor cladding

    SciTech Connect

    Orlov, Andrey; Degueldre, Claude; Kaufmann, Wilfried

    2013-01-15

    The buildup of corrosion product deposits (CRUD) on the fuel cladding of the boiling water reactor (BWR) before and after zinc injection has been investigated by applying local experimental analytical techniques. Under the BWR water chemistry conditions, Zn addition together with the presence of Ni and Mn induce the formation of (Zn,Ni,Mn)[Fe{sub 2}O{sub 4}] spinel solid solutions. X-ray absorption spectroscopy (XAS) revealed inversion ratios of cation distribution in spinels deposited from the solid solution. Based on this information, a two-site ferrite spinel solid solution model is proposed. Electron probe microanalysis (EPMA) and extended X-ray absorption fine structure (EXAFS) findings suggest the zinc-rich ferrite spinels formation on BWR fuel cladding mainly at lower pin. - Graphical Abstract: Analysis of spinels in corrosion product deposits on boiling water reactor fuel rod. Combining EPMA and XAFS results: schematic representation of the ferrite spinels in terms of the end members and their extent of inversion. Note that the ferrites are represented as a surface between the normal (upper plane, M[Fe{sub 2}]O{sub 4}) and the inverse (lower plane, Fe[MFe]O{sub 4}). Actual compositions red Black-Small-Square for the specimen at low elevation (810 mm), blue Black-Small-Square for the specimen at mid elevation (1800 mm). The results have an impact on the properties of the CRUD material. Highlights: Black-Right-Pointing-Pointer Buildup of corrosion product deposits on fuel claddings of a boiling water reactor (BWR) are investigated. Black-Right-Pointing-Pointer Under BWR water conditions, Zn addition with Ni and Mn induced formation of (Zn,Ni,Mn)[Fe{sub 2}O{sub 4}]. Black-Right-Pointing-Pointer X-Ray Adsorption Spectroscopy (XAS) revealed inversion of cations in spinel solid solutions. Black-Right-Pointing-Pointer Zinc-rich ferrite spinels are formed on BWR fuel cladding mainly at lower pin elevations.

  3. Study and comparison of two enzyme membrane reactors for fatty acids and glycerol production

    SciTech Connect

    Molinari, R.; Santoro, M.E.; Drioli, E. . Dept. of Chemical Engineering and Materials Inst. on Membranes and Chemical Reactors-CNR, Arcavacata di Rende )

    1994-11-01

    Two enzyme membrane reactors (EMR), (1) with one substrate (olive oil) in an oil-in-water emulsion (E-EMR) and (2) with two separated liquid phases (oil and water) (TSLP-EMR), have been studied for the conversion of the triglycerides to fatty acids and glycerol. The enzyme was Candida cylindracea lipase confined on the pressurized face or entrapped in the sponge side of capillary ultrafiltration membranes. Two methods for immobilizing the enzyme in the TSLP-EMR were used: ultrafiltration on a virgin membrane and ultrafiltration on glutaraldehyde pretreated membranes. A multiple use of the reactor was obtained immobilizing the enzyme on the membrane preactivated with glutaraldehyde. The TSLP-EMR showed a specific activity of 0.529 mmol/(mg[center dot]h) versus a specific activity of 0.170 mmol/(mg[center dot]h) of the E-EMR. The rate of fatty acid production in the TSLP-EMR was linear with time showing no enzyme deactivation in an operating time of 80 h. The kinetics observed in the two reactors was different: an equilibrium reaction product-inhibited for the E-EMR and an apparent irreversible reaction of zero order for the TSLP-EMR. Taking into account that in the TSLP-EMR, compared to the E-EMR, (1) the specific activity was higher, (2) the specific rate was constant with the time, and (3) the two products were already separated after the reaction, the TSLP-EMR configuration seems the more convenient.

  4. Conceptual Design of Low-Temperature Hydrogen Production and High-Efficiency Nuclear Reactor Technology

    NASA Astrophysics Data System (ADS)

    Fukushima, Kimichika; Ogawa, Takashi

    Hydrogen, a potential alternative energy source, is produced commercially by methane (or LPG) steam reforming, a process that requires high temperatures, which are produced by burning fossil fuels. However, as this process generates large amounts of CO2, replacement of the combustion heat source with a nuclear heat source for 773-1173K processes has been proposed in order to eliminate these CO2 emissions. In this paper, a novel method of nuclear hydrogen production by reforming dimethyl ether (DME) with steam at about 573K is proposed. From a thermodynamic equilibrium analysis of DME steam reforming, the authors identified conditions that provide high hydrogen production fraction at low pressure and temperatures of about 523-573K. By setting this low-temperature hydrogen production process upstream from a turbine and nuclear reactor at about 573K, the total energy utilization efficiency according to equilibrium mass and heat balance analysis is about 50%, and it is 75%for a fast breeder reactor (FBR), where turbine is upstream of the reformer.

  5. Analysis of fission product revaporization in a BWR Reactor Coolant System during a station blackout accident

    SciTech Connect

    Yang, J.W.; Schmidt, E.; Cazzoli, E.; Khatib-Rahbar, M.

    1988-01-01

    This paper presents an analysis of fission product revaporization from the Reactor Coolant System (RCS) following the Reactor Pressure Vessel (RPV) failure. The station blackout accident in a BWR Mark I Power Plant was considered. The TRAPMELT3 models for vaporization, chemisorption, and the decay heating of RCS structures and gases were used and extended beyond the RPV failure in the analysis. The RCS flow models based on the density-difference or pressure-difference between the RCS and containment pedestal region were developed to estimate the RCS outflow which carries the revaporized fission product to the containment. A computer code called REVAP was developed for the analysis. The REVAP code was incorporated with the MARCH, TRAPMELT3 and NAUA codes from the Source Term Code Package (STCP) to estimate the impact of revaporization on environmental release. The results show that the thermal-hydraulic conditions between the RCS and the pedestal region are important factors in determining the magnitude of revaporization and subsequent release of the volatile fission product into the environment. 6 refs., 8 figs.

  6. Computational and experimental prediction of dust production in pebble bed reactors -- Part I

    SciTech Connect

    Maziar Rostamian; Gannon Johnson; Mie Hiruta; Gabriel P. Potirniche; Abderrafi M. Ougouag; Joshua J. Cogliati; Akira Tokuhiro

    2013-10-01

    This paper describes the computational modeling and simulation, and experimental testing of graphite moderators in frictional contacts as anticipated in a pebble bed reactor. The potential of carbonaceous particulate generation due to frictional contact at the surface of pebbles and the ensuing entrainment and transport into the gas coolant are safety concerns at elevated temperatures under accident scenarios such as air ingress in the high temperature gas-cooled reactor. The safety concerns are due to the documented ability of carbonaceous particulates to adsorb fission products and transport them in the primary circuit of the pebble bed reactor, thus potentially giving rise to a relevant source term under accident scenarios. Here, a finite element approach is implemented to develop a nonlinear wear model in air environment. In this model, material wear coefficient is related to the changes in asperity height during wear. The present work reports a comparison between the finite element simulations and the experimental results obtained using a custom-designed tribometer. The experimental and computational results are used to estimate the quantity of nuclear grade graphite dust produced from a typical anticipated configuration. In Part II, results from a helium environment at higher temperatures and pressures are experimentally studied.

  7. On the fusion triple product and fusion power gain of tokamak pilot plants and reactors

    NASA Astrophysics Data System (ADS)

    Costley, A. E.

    2016-06-01

    The energy confinement time of tokamak plasmas scales positively with plasma size and so it is generally expected that the fusion triple product, nTτ E, will also increase with size, and this has been part of the motivation for building devices of increasing size including ITER. Here n, T, and τ E are the ion density, ion temperature and energy confinement time respectively. However, tokamak plasmas are subject to operational limits and two important limits are a density limit and a beta limit. We show that when these limits are taken into account, nTτ E becomes almost independent of size; rather it depends mainly on the fusion power, P fus. In consequence, the fusion power gain, Q fus, a parameter closely linked to nTτ E is also independent of size. Hence, P fus and Q fus, two parameters of critical importance in reactor design, are actually tightly coupled. Further, we find that nTτ E is inversely dependent on the normalised beta, β N; an unexpected result that tends to favour lower power reactors. Our findings imply that the minimum power to achieve fusion reactor conditions is driven mainly by physics considerations, especially energy confinement, while the minimum device size is driven by technology and engineering considerations. Through dedicated R&D and parallel developments in other fields, the technology and engineering aspects are evolving in a direction to make smaller devices feasible.

  8. Scale-up and performance of an immobilized cell reactor separator for the production of ethanol from whey lactose

    SciTech Connect

    Dale, M.C.; Okos, M.R.

    1988-01-01

    An adsorbed microbial cell, trickle flow, reactor incorporating a circulating gas phase to simultaneously separate a volatile inhibitory product has shown high fermentation rates and effective product separation on a 1 in. diameter lab bench scale. Carbon dioxide generated by the fermentation is recirculated to strip the volatile fermentation product from the fermentation broth. Random and structured packings were evaluated and a parallel type structured packing was developed consisting of a plates of absorbant material to which cells are adsorbed and spaced to allow passage of the circulating gas stream. The substrate solution flows by gravity in a capillary flow fashion down through the plates in which the cells are immobilized. The theoretical reactor separation and fermentation performance as a function of plate thickness and gas channel spacing was evaluated. This reactor has been scaled up to a 6 in. ID reactor with a total reactor volume of about 50 liters using a spiral wound version of the parallel plates, and then to a 24 in. ID reactor with a reactor volume of about 1300 liters. 16 refs., 12 figs., 1 tab.

  9. Process development and modeling of fluidized-bed reactor with coimmobilized biocatalyst for fuel ethanol production

    NASA Astrophysics Data System (ADS)

    Sun, May Yongmei

    This research focuses on two steps of commercial fuel ethanol production processes: the hydrolysis starch process and the fermentation process. The goal of this research is to evaluate the performance of co-immobilized biocatalysts in a fluidized bed reactor with emphasis on economic and engineering aspects and to develop a predictive mathematical model for this system. The productivity of an FBR is higher than productivity of a traditional batch reactor or CSTR. Fluidized beds offer great advantages over packed beds for immobilized cells when small particles are used or when the reactant feed contains suspended solids. Plugging problems, excessive pressure drops (and thus attrition), or crushing risks may be avoided. No mechanical stirring is required as mixing occurs due to the natural turbulence in the fluidized process. Both enzyme and microorganism are immobilized in one catalyst bead which is called co-immobilization. Inside this biocatalyst matrix, starch is hydrolyzed by the enzyme glucoamylase to form glucose and then converted to ethanol and carbon dioxide by microorganisms. Two biocatalysts were evaluated: (1) co-immobilized yeast strain Saccharomyces cerevisiae and glucoamylase. (2) co-immobilized Zymomonas mobilis and glucoamylase. A co-immobilized biocatalyst accomplishes the simultaneous saccharification and fermentation (SSF process). When compared to a two-step process involving separate saccharification and fermentation stages, the SSF process has productivity values twice that given by the pre-saccharified process when the time required for pre-saccharification (15--25 h) was taken into account. The SSF process should also save capital cost. The information about productivity, fermentation yield, concentration profiles along the bed, ethanol inhibition, et al., was obtained from the experimental data. For the yeast system, experimental results showed that: no apparent decrease of productivity occurred after two and half months, the productivity was 25--44g/L-hr (based on reactor volume), the average yield was 0.45 g ethanol/g starch, the biocatalyst retained physical integrity and contamination did not affect fermentation. For the Z. mobilis system the maximum volumetric productivity was 38 g ethanol/L-h, the average yield was 0.51 g ethanol/g starch and the FBR was successfully operated for almost one month. In order to develop, scale-up and economically evaluate this system more efficiently, a predictive mathematical model that is based on fundamental principles was developed and verified. This model includes kinetics of reactions, transport phenomena of the reactant and product by diffusion within the biocatalyst bead, and the hydrodynamics of the three phase fluidized bed. The co-immobilized biocatalyst involves a consecutive reaction mechanism The mathematical descriptions of the effectiveness factors of reactant and the intermediate product were developed. Hydrodynamic literature correlations were used to develop the dispersion coefficient and gas, liquid, and solid holdup. The solutions of coupled non-linear second order equations for biocatalyst bead and reactor together with the boundary conditions were solved numerically. This model gives considerable information about the system, such as concentration profiles inside both the beads and column, flow rate and feed concentration influences on productivity and phase hold up, and the influence of enzyme and cell mass loading in the catalyst. This model is generic in nature such that it can be easily applied to a diverse set of applications and operating conditions.

  10. Functionally gradient material for membrane reactors to convert methane gas into value-added products

    DOEpatents

    Balachandran, Uthamalingam; Dusek, Joseph T.; Kleefisch, Mark S.; Kobylinski, Thadeus P.

    1996-01-01

    A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials.

  11. Functionally gradient material for membrane reactors to convert methane gas into value-added products

    DOEpatents

    Balachandran, U.; Dusek, J.T.; Kleefisch, M.S.; Kobylinski, T.P.

    1996-11-12

    A functionally gradient material for a membrane reactor for converting methane gas into value-added-products includes an outer tube of perovskite, which contacts air; an inner tube which contacts methane gas, of zirconium oxide, and a bonding layer between the perovskite and zirconium oxide layers. The bonding layer has one or more layers of a mixture of perovskite and zirconium oxide, with the layers transitioning from an excess of perovskite to an excess of zirconium oxide. The transition layers match thermal expansion coefficients and other physical properties between the two different materials. 7 figs.

  12. Environmental characterization of two potential locations at Hanford for a new production reactor

    SciTech Connect

    Watson, E.C.; Becker, C.D.; Fitzner, R.E.; Gano, K.A.; Imhoff, K.L.; McCallum, R.F.; Myers, D.A.; Page, T.L.; Price, K.R.; Ramsdell, J.V.; Rice D.G.; Schreiber D.L.; Skumatz L.A.; Sommer D.J.; Tawil J.J.; Wallace R.W.; Watson D.G.

    1984-09-01

    This report describes various environmental aspects of two areas on the Hanford Site that are potential locations for a New Production Reactor (NPR). The area known as the Skagit Hanford Site is considered the primary or reference site. The second area, termed the Firehouse Site, is considered the alternate site. The report encompasses an environmental characterization of these two potential NPR locations. Eight subject areas are covered: geography and demography; ecology; meteorology; hydrology; geology; cultural resources assessment; economic and social effects of station construction and operation; and environmental monitoring. 80 refs., 68 figs., 109 tabs.

  13. Feasibility study for production of I-131 radioisotope using MNSR research reactor.

    PubMed

    Elom Achoribo, A S; Akaho, Edward H K; Nyarko, Benjamin J B; Osae Shiloh, K D; Odame Duodu, Godfred; Gibrilla, Abass

    2012-01-01

    A feasibility study for (131)I production using a Low Power Research Reactor was conducted to predict the yield of (131)I by cyclic activation technique. A maximum activity of 5.1GBq was achieved through simulation using FORTRAN 90, for an irradiation of 6h. But experimentally only 4h irradiation could be done, which resulted in an activity of 4.0×10(5)Bq. The discrepancy in the activities was due to the fact that beta decays released during the process could not be considered. PMID:21900016

  14. Fission Product Monitoring of TRISO Coated Fuel For The Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John K. Hartwell; John b. Walter

    2010-10-01

    The US Department of Energy has embarked on a series of tests of TRISO-coated particle reactor fuel intended for use in the Very High Temperature Reactor (VHTR) as part of the Advanced Gas Reactor (AGR) program. The AGR-1 TRISO fuel experiment, currently underway, is the first in a series of eight fuel tests planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The AGR-1 experiment reached a peak compact averaged burn up of 9% FIMA with no known TRISO fuel particle failures in March 2008. The burnup goal for the majority of the fuel compacts is to have a compact averaged burnup greater than 18% FIMA and a minimum compact averaged burnup of 14% FIMA. At the INL the TRISO fuel in the AGR-1 experiment is closely monitored while it is being irradiated in the ATR. The effluent monitoring system used for the AGR-1 fuel is the Fission Product Monitoring System (FPMS). The FPMS is a valuable tool that provides near real-time data indicative of the AGR-1 test fuel performance and incorporates both high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based gross radiation monitors. To quantify the fuel performance, release-to-birth ratios (R/B’s) of radioactive fission gases are computed. The gamma-ray spectra acquired by the AGR-1 FPMS are analyzed and used to determine the released activities of specific fission gases, while a dedicated detector provides near-real time count rate information. Isotopic build up and depletion calculations provide the associated isotopic birth rates. This paper highlights the features of the FPMS, encompassing the equipment, methods and measures that enable the calculation of the release-to-birth ratios. Some preliminary results from the AGR-1 experiment are also presented.

  15. Fission Product Monitoring of TRISO Coated Fuel For The Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John K Hartwell; John B. Walter

    2008-09-01

    The US Department of Energy has embarked on a series of tests of TRISO-coated particle reactor fuel intended for use in the Very High Temperature Reactor (VHTR) as part of the Advanced Gas Reactor (AGR) program. The AGR-1 TRISO fuel experiment, currently underway, is the first in a series of eight fuel tests planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The AGR-1 experiment reached a peak compact averaged burn up of 9% FIMA with no known TRISO fuel particle failures in March 2008. The burnup goal for the majority of the fuel compacts is to have a compact averaged burnup greater than 18% FIMA and a minimum compact averaged burnup of 14% FIMA. At the INL the TRISO fuel in the AGR-1 experiment is closely monitored while it is being irradiated in the ATR. The effluent monitoring system used for the AGR-1 fuel is the Fission Product Monitoring System (FPMS). The FPMS is a valuable tool that provides near real-time data indicative of the AGR-1 test fuel performance and incorporates both high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based gross radiation monitors. To quantify the fuel performance, release-to-birth ratios (R/B’s) of radioactive fission gases are computed. The gamma-ray spectra acquired by the AGR-1 FPMS are analyzed and used to determine the released activities of specific fission gases, while a dedicated detector provides near-real time count rate information. Isotopic build up and depletion calculations provide the associated isotopic birth rates. This paper highlights the features of the FPMS, encompassing the equipment, methods and measures that enable the calculation of the release-to-birth ratios. Some preliminary results from the AGR-1 experiment are also presented.

  16. Modeling of Nitrous Oxide Production from Nitritation Reactors Treating Real Anaerobic Digestion Liquor.

    PubMed

    Wang, Qilin; Ni, Bing-Jie; Lemaire, Romain; Hao, Xiaodi; Yuan, Zhiguo

    2016-01-01

    In this work, a mathematical model including both ammonium oxidizing bacteria (AOB) and heterotrophic bacteria (HB) is constructed to predict N2O production from the nitritation systems receiving the real anaerobic digestion liquor. This is for the first time that N2O production from such systems was modeled considering both AOB and HB. The model was calibrated and validated using experimental data from both lab- and pilot-scale nitritation reactors. The model predictions matched the dynamic N2O, ammonium, nitrite and chemical oxygen demand data well, supporting the capability of the model. Modeling results indicated that HB are the dominant contributor to N2O production in the above systems with the dissolved oxygen (DO) concentration of 0.5-1.0 mg O2/L, accounting for approximately 75% of N2O production. The modeling results also suggested that the contribution of HB to N2O production decreased with the increasing DO concentrations, from 75% at DO = 0.5 mg O2/L to 25% at DO = 7.0 mg O2/L, with a corresponding increase of the AOB contribution (from 25% to 75%). Similar to HB, the total N2O production rate also decreased dramatically from 0.65 to 0.25 mg N/L/h when DO concentration increased from 0.5 to 7.0 mg O2/L. PMID:27125491

  17. Modeling of Nitrous Oxide Production from Nitritation Reactors Treating Real Anaerobic Digestion Liquor

    PubMed Central

    Wang, Qilin; Ni, Bing-Jie; Lemaire, Romain; Hao, Xiaodi; Yuan, Zhiguo

    2016-01-01

    In this work, a mathematical model including both ammonium oxidizing bacteria (AOB) and heterotrophic bacteria (HB) is constructed to predict N2O production from the nitritation systems receiving the real anaerobic digestion liquor. This is for the first time that N2O production from such systems was modeled considering both AOB and HB. The model was calibrated and validated using experimental data from both lab- and pilot-scale nitritation reactors. The model predictions matched the dynamic N2O, ammonium, nitrite and chemical oxygen demand data well, supporting the capability of the model. Modeling results indicated that HB are the dominant contributor to N2O production in the above systems with the dissolved oxygen (DO) concentration of 0.5–1.0 mg O2/L, accounting for approximately 75% of N2O production. The modeling results also suggested that the contribution of HB to N2O production decreased with the increasing DO concentrations, from 75% at DO = 0.5 mg O2/L to 25% at DO = 7.0 mg O2/L, with a corresponding increase of the AOB contribution (from 25% to 75%). Similar to HB, the total N2O production rate also decreased dramatically from 0.65 to 0.25 mg N/L/h when DO concentration increased from 0.5 to 7.0 mg O2/L. PMID:27125491

  18. Integrated side-stream reactor for biological nutrient removal and minimization of sludge production.

    PubMed

    Coma, M; Rovira, S; Canals, J; Colprim, J

    2015-01-01

    Integrated processes to reduce in situ the sludge production in wastewater treatment plants are gaining attention in order to facilitate excess sludge management. In contrast to post-treatments, such as anaerobic digestion which is placed between the activated sludge system and dewatering processes, integrated technologies are placed in the sludge return line. This study evaluates the application of an anoxic side-stream reactor (SSR) which creates a physiological shock and uncouples the biomass metabolism and diverts the activity from assimilation for biosynthesis to non-growth activities. The effect of this system in biological nutrient removal for both nitrogen and phosphorus was evaluated for the anaerobic, anoxic and aerobic reactors. The RedOx potential within the SSR was maintained at -150 mV while the sludge loading rate was modified by increasing the percentage of recycled activated sludge feed to the SSR (0 and 40% at laboratory scale and 0, 10, 50 and 100% at pilot scale). The use of the SSR presented a slight reduction of phosphorus removal but maintained the effluent quality to the required discharge values. Nitrogen removal efficiency increased from 75 to 86% while reducing the sludge production rate by 18.3%. PMID:25860709

  19. Production of Thorium-229 at the ORNL High Flux Isotope Reactor

    SciTech Connect

    Boll, Rose Ann; Garland, Marc A; Mirzadeh, Saed

    2008-01-01

    The investigation of targeted cancer therapy using -emitters has developed considerably in recent years and clinical trials have generated promising results. In particular, the initial clinical trials for treatment of acute myeloid leukemia have demonstrated the effectiveness of the -emitter 213Bi in killing cancer cells [1]. Pre-clinical studies have also shown the potential application of both 213Bi and its 225Ac parent radionuclide in a variety of cancer systems and targeted radiotherapy [2]. Bismuth-213 is obtained from a radionuclide generator system from decay of the 10-d 225Ac parent, a member of the 7340-y 229Th chain. Currently, 233U is the only viable source for high purity 229Th; however, due to increasing difficulties associated with 233U safeguards, processing additional 233U is presently unfeasible. The recent decision to downblend and dispose of enriched 233U further diminished the prospects for extracting 229Th from 233U stock. Nevertheless, the anticipated growth in demand for 225Ac may soon exceed the levels of 229Th (~40 g or ~8 Ci; ~80 times the current ORNL 229Th stock) present in the aged 233U stockpile. The alternative routes for the production of 229Th, 225Ra and 225Ac include both reactor and accelerator approaches [3]. Here, we describe production of 229Th via neutron transmutation of 226Ra targets in the ORNL High Flux Isotope Reactor (HFIR).

  20. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    SciTech Connect

    Shwetha Ramkumar; Mahesh Iyer; Danny Wong; Himanshu Gupta; Bartev Sakadjian; Liang-Lhih Fan

    2008-09-30

    High purity hydrogen is commercially produced from syngas by the Water Gas Shift Reaction (WGSR) in high and low temperature shift reactors using iron oxide and copper catalysts respectively. However, the WGSR is thermodynamically limited at high temperatures towards hydrogen production necessitating excess steam addition and catalytic operation. In the calcium looping process, the equilibrium limited WGSR is driven forward by the incessant removal of CO{sub 2} by-product through the carbonation of calcium oxide. At high pressures, this process obviates the need for a catalyst and excess steam requirement, thereby removing the costs related to the procurement and deactivation of the catalyst and steam generation. Thermodynamic analysis for the combined WGS and carbonation reaction was conducted. The combined WGS and carbonation reaction was investigated at varying pressures, temperatures and S/C ratios using a bench scale reactor system. It was found that the purity of hydrogen increases with the increase in pressure and at a pressure of 300 psig, almost 100% hydrogen is produced. It was also found that at high pressures, high purity hydrogen can be produced using stoichiometric quantities of steam. On comparing the catalytic and non catalytic modes of operation in the presence of calcium oxide, it was found that there was no difference in the purity of hydrogen produced at elevated pressures. Multicyclic reaction and regeneration experiments were also conducted and it was found that the purity of hydrogen remains almost constant after a few cycles.

  1. Fatty acids production from hydrogen and carbon dioxide by mixed culture in the membrane biofilm reactor.

    PubMed

    Zhang, Fang; Ding, Jing; Zhang, Yan; Chen, Man; Ding, Zhao-Wei; van Loosdrecht, Mark C M; Zeng, Raymond J

    2013-10-15

    Gasification of waste to syngas (H2/CO2) is seen as a promising route to a circular economy. Biological conversion of the gaseous compounds into a liquid fuel or chemical, preferably medium chain fatty acids (caproate and caprylate) is an attractive concept. This study for the first time demonstrated in-situ production of medium chain fatty acids from H2 and CO2 in a hollow-fiber membrane biofilm reactor by mixed microbial culture. The hydrogen was for 100% utilized within the biofilms attached on the outer surface of the hollow-fiber membrane. The obtained concentrations of acetate, butyrate, caproate and caprylate were 7.4, 1.8, 0.98 and 0.42 g/L, respectively. The biomass specific production rate of caproate (31.4 mmol-C/(L day g-biomass)) was similar to literature reports for suspended cell cultures while for caprylate the rate (19.1 mmol-C/(L day g-biomass)) was more than 6 times higher. Microbial community analysis showed the biofilms were dominated by Clostridium spp., such as Clostridium ljungdahlii and Clostridium kluyveri. This study demonstrates a potential technology for syngas fermentation in the hollow-fiber membrane biofilm reactors. PMID:23941982

  2. Radioisotope production at the University of Missouri Research Reactor: Past and present

    SciTech Connect

    Ehrhardt, G.J.; Ketring, A.R.; Gunn, S.L.

    1993-12-31

    Isotope production for industrial, medical, and specialty research use has been a major effort at the University of Missouri Research Reactor (MURR) since its initial critically in 1966, due primarily to the MURR`s high thermal neutron flux and ongoing commitment to reliability for its customers and research users. The history of this effort will be described, from the early supply of (n,gamma) Mo-99 for Tc-99m generators to the current program of production of high specific activity isotopes such as Re-186, Sm-153, Ho-166, Lu-177, and Re-188 which support the renaissance now taking place in nuclear medicine therapy. Using {open_quotes}guidance{close_quotes} methods as varied as seed implantation, microsphere entrapment, and chemical or immunochemical uptake, this resurgence of internal radioisotope therapy techniques depends, particularly in its more elegant forms, on just such high specific activity, beta-emitting isotopes.

  3. Improved lignin pyrolysis for phenolics production in a bubbling bed reactor--Effect of bed materials.

    PubMed

    Li, Dongbing; Briens, Cedric; Berruti, Franco

    2015-01-01

    Lignin pyrolysis was studied in a bubbling fluidized bed reactor equipped with a fractional condensation train, using nitrogen as the fluidization gas. The effect of different bed materials (silica sand, lignin char, activated lignin char, birch bark char, and foamed glass beads) on bio-oil yield and quality was investigated for a pyrolysis temperature of 550 °C. Results how that a bed of activated lignin char is preferable to the commonly used silica sand: pyrolysis of Kraft lignin with a bed of activated lignin char not only provides a pure char product, but also a higher dry bio-oil yield (with a relative increase of 43%), lower pyrolytic water production, and better bio-oil quality. The bio-oil obtained from Kraft lignin pyrolysis with a bed of activated lignin char has a lower average molecular weight, less tar, more phenolics, and less acidity than when sand is used as bed material. PMID:25863324

  4. Hydraulic retention time effects on wastewater nutrient removal and bioproduct production via rotating algal biofilm reactor.

    PubMed

    Iman Shayan, Sahand; Agblevor, Foster A; Bertin, Lorenzo; Sims, Ronald C

    2016-07-01

    Rotating algal biofilm reactor (RABR) technology was successfully employed in an effective strategy to couple the removal of wastewater nutrients with accumulation of valuable bioproducts by grown algae. A secondary stage municipal wastewater was fed to the developed system and the effects of the hydraulic retention time (HRT) parameter on both nutrient removal and bioproduct production were evaluated under fed-batch operation mode. Two sets of bench scale RABRs were designed and operated with HRTs of 2 and 6days in order to provide competitive environment for algal growth. The HRT significantly affected nitrogen and phosphorus uptakes along with lipid and starch accumulations by microalgae in harvested biofilms. Domination of nitrogen removal in 2-day HRT with higher lipid accumulation (20% on dried weight basis) and phosphorus removal in 6-day HRT with higher starch production (27% on dried weight basis) was observed by comparing the performances of the RABRs in duplicate runs. PMID:27038261

  5. 76 FR 51023 - Richland-Stryker Generation LLC; Supplemental Notice That Initial Market-Based Rate Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Richland-Stryker Generation LLC; Supplemental Notice That Initial Market... in the above-referenced proceeding of Richland-Stryker Generation LLC's application for...

  6. Method of production H/sub 2/ using a rotating drum reactor with a pulse jet heat source

    DOEpatents

    Paulson, L.E.

    1988-05-13

    A method of producing hydrogen by an endothermic steam-carbon reaction using a rotating drum reactor and a pulse jet combustor. The pulse jet combustor uses coal dust as a fuel to provide reaction temperatures of 1300/degree/ to 1400/degree/F. Low-rank coal, water, limestone and catalyst are fed into the drum reactor where they are heated, tumbled and reacted. Part of the reaction product from the rotating drum reactor is hydrogen which can be utilized in suitable devices. 1 fig.

  7. EVALUATION OF ACTIVATION PRODUCTS IN REMAINING IN REMAINING K-, L- AND C-REACTOR STRUCTURES

    SciTech Connect

    Vinson, D.; Webb, R.

    2010-09-30

    An analytic model and calculational methodology was previously developed for P-reactor and R-reactor to quantify the radioisotopes present in Savannah River Site (SRS) reactor tanks and the surrounding structural materials as a result of neutron activation of the materials during reactor operation. That methodology has been extended to K-reactor, L-reactor, and C-reactor. The analysis was performed to provide a best-estimate source term input to the Performance Assessment for an in-situ disposition strategy by Site Decommissioning and Demolition (SDD). The reactor structure model developed earlier for the P-reactor and R-reactor analyses was also used for the K-reactor and L-reactor. The model was suitably modified to handle the larger Creactor tank and associated structures. For all reactors, the structure model consisted of 3 annular zones, homogenized by the amount of structural materials in the zone, and 5 horizontal layers. The curie content on an individual radioisotope basis and total basis for each of the regions was determined. A summary of these results are provided herein. The efficacy of this methodology to accurately predict the radioisotopic content of the reactor systems in question has been demonstrated and is documented in Reference 1. As noted in that report, results for one reactor facility cannot be directly extrapolated to other SRS reactors.

  8. Studies of Plutonium-238 Production at the High Flux Isotope Reactor

    SciTech Connect

    Lastres, Oscar; Chandler, David; Jarrell, Joshua J; Maldonado, G. Ivan

    2011-01-01

    The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is a versatile 85 MW{sub th}, pressurized, light water-cooled and -moderated research reactor. The core consists of two fuel elements, an inner fuel element (IFE) and an outer fuel element (OFE), each constructed of involute fuel plates containing high-enriched-uranium (HEU) fuel ({approx}93 wt% {sup 235}U/U) in the form of U{sub 3}O{sub 8} in an Al matrix and encapsulated in Al-6061 clad. An over-moderated flux trap is located in the center of the core, a large beryllium reflector is located on the outside of the core, and two control elements (CE) are located between the fuel and the reflector. The flux trap and reflector house numerous experimental facilities which are used for isotope production, material irradiation, and cold/thermal neutron scattering. Over the past five decades, the US Department of Energy (DOE) and its agencies have been producing radioisotope power systems used by the National Aeronautics and Space Administration (NASA) for unmanned, long-term space exploration missions. Plutonium-238 is used to power Radioisotope Thermoelectric Generators (RTG) because it has a very long half-life (t{sub 1/2} {approx} 89 yr.) and it generates about 0.5 watts/gram when it decays via alpha emission. Due to the recent shortage and uncertainty of future production, the DOE has proposed a plan to the US Congress to produce {sup 238}Pu by irradiating {sup 237}Np as early as in fiscal year 2011. An annual production rate of 1.5 to 2.0 kg of {sup 238}Pu is expected to satisfy these needs and could be produced in existing national nuclear facilities like HFIR and the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Reactors at the Savannah River Site were used in the past for {sup 238}Pu production but were shut down after the last production in 1988. The nation's {sup 237}Np inventory is currently stored at INL. A plan for producing {sup 238}Pu at US research reactor facilities such as the High Flux Isotope Reactor at ORNL has been initiated by the US DOE and NASA for space exploration needs. Two Monte Carlo-based depletion codes, TRITON (ORNL) and VESTA (IRSN), were used to study the {sup 238}Pu production rates with varying target configurations in a typical HFIR fuel cycle. Preliminary studies have shown that approximately 11 grams and within 15 to 17 grams of {sup 238}Pu could be produced in the first irradiation cycle in one small and one large VXF facility, respectively, when irradiating fresh target arrays as those herein described. Important to note is that in this study we discovered that small differences in assumptions could affect the production rates of Pu-238 observed. The exact flux at a specific target location can have a significant impact upon production, so any differences in how the control elements are modeled as a function of exposure, will also cause differences in production rates. In fact, the surface plot of the large VXF target Pu-238 production shown in Figure 3 illustrates that the pins closest to the core can potentially have production rates as high as 3 times those of pins away from the core, thus implying that a cycle-to-cycle rotation of the targets may be well advised. A methodology for generating spatially-dependent, multi-group self-shielded cross sections and flux files with the KENO and CENTRM codes has been created so that standalone ORIGEN-S inputs can be quickly constructed to perform a variety of {sup 238}Pu production scenarios, i.e. combinations of the number of arrays loaded and the number of irradiation cycles. The studies herein shown with VESTA and TRITON/KENO will be used to benchmark the standalone ORIGEN.

  9. Letter report: Title listing of daily operating data on Hanford single-pass reactors, 1944--1971

    SciTech Connect

    Gydesen, S.P.

    1992-02-01

    The primary objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that populations and individuals could have received as a result of emissions from Hanford Site operations since 1944, with descriptions of the uncertainties inherent in such estimates. A secondary objective is to make project documentation and Hanford-originated references used in the reports available to the public. Hanford-originated documents of potential interest and/or use to the HEDR Project are made publicly available through the US Government's National Technical Information Service and placed in the US Department of Energy Richland Field Office (RL) Public Reading Room in Richland, Washington. Project work is conducted under several technical tasks, among which is the Source Terms Task. Under this task, estimates of radioactive emissions from Hanford facilities since 1944 are developed. These estimates are based on historical measurements and production information. The Information Resources Task identifies and retrieves historical production operating information for developing source terms. The purpose of this letter report is to identify documents that record daily reactor operating information at the Hanford Site for the years 1944--1971. Complete bibliographic citations and sample pages from each different format for Hanford reactor operations data are included.

  10. Reservoir characterization of the Mississippian Ratcliffe, Richland County, Montana, Williston Basin. Topical report, September 1997

    SciTech Connect

    Sippel, M.; Luff, K.D.; Hendricks, M.L.

    1998-07-01

    This topical report is a compilation of characterizations by different disciplines of the Mississippian Ratcliffe in portions of Richland County, MT. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity and methods for improved recovery. The report covers investigations of geology, petrography, reservoir engineering and seismic. The Ratcliffe is a low permeability oil reservoir which appears to be developed across much of the study area and occurs across much of the Williston Basin. The reservoir has not been a primary drilling target in the study area because average reserves have been insufficient to payout the cost of drilling and completion despite the application of hydraulic fracture stimulation. Oil trapping does not appear to be structurally controlled. For the Ratcliffe to be a viable drilling objective, methods need to be developed for (1) targeting better reservoir development and (2) better completions. A geological model is presented for targeting areas with greater potential for commercial reserves in the Ratcliffe. This model can be best utilized with the aid of 3D seismic. A 3D seismic survey was acquired and is used to demonstrate a methodology for targeting the Ratcliffe. Other data obtained during the project include oriented core, special formation-imaging log, pressure transient measurements and oil PVT. Although re-entry horizontal drilling was unsuccessfully tested, this completion technology should improve the economic viability of the Ratcliffe. Reservoir simulation of horizontal completions with productivity of three times that of a vertical well suggested two or three horizontal wells in a 258-ha (640-acre) area could recover sufficient reserves for profitable drilling.

  11. Evaluation of injury/illness recordkeeping pilot course taught in Richland, Washington, June 18, 1992

    SciTech Connect

    Wright, T.S.

    1992-11-01

    This report summarizes trainee evaluations for the Safety Training Section course, Injury/Illness Recordkeeping which was conducted June 18, at Hanford, in richland, Washington. This class was the second pilot course taught. This class was designed to aquaint attendees with DOE orders 5484.1, 5484.1A, draft 3 and OSHA regulations found in 29 CFR 1904.

  12. Richland Community College's Self-Study and Institutional Plan, Spring 1993.

    ERIC Educational Resources Information Center

    Richland Community Coll., Decatur, IL.

    Providing detailed information on Richland Community College (RCC), in Decatur, Illinois, this report reviews institutional planning, services, and assessment at the college and presents recommendations for improvement. The first chapter reviews the history of RCC, focusing on the college's accreditation history. The second chapter describes RCC's…

  13. Actinide, Activation Product and Fission Product Decay Data for Reactor-based Applications

    SciTech Connect

    Perry, R.J.; Dean, C.J.; Nichols, A.L.

    2014-06-15

    The UK Activation Product Decay Data Library was first released in September 1977 as UK-PADD1, to be followed by regular improvements on an almost yearly basis up to the assembly of UKPADD6.12 in March 2013. Similarly, the UK Heavy Element and Actinide Decay Data Library followed in December 1981 as UKHEDD1, with the implementation of various modifications leading to UKHEDD2.6, February 2008. Both the data content and evaluation procedures are defined, and the most recent evaluations are described in terms of specific radionuclides and the resulting consistency of their recommended decay-data files. New versions of the UKPADD and UKHEDD libraries are regularly submitted to the NEA Data Bank for possible inclusion in the JEFF library.

  14. Fission Product Monitoring and Release Data for the Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John B. Walter; Jason M. Harp; Mark W. Drigert; Edward L. Reber

    2010-10-01

    The AGR-1 experiment is a fueled multiple-capsule irradiation experiment that was irradiated in the Advanced Test Reactor (ATR) from December 26, 2006 until November 6, 2009 in support of the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Fuel Development and Qualification program. An important measure of the fuel performance is the quantification of the fission product releases over the duration of the experiment. To provide this data for the inert fission gasses(Kr and Xe), a fission product monitoring system (FPMS) was developed and implemented to monitor the individual capsule effluents for the radioactive species. The FPMS continuously measured the concentrations of various krypton and xenon isotopes in the sweep gas from each AGR-1 capsule to provide an indicator of fuel irradiation performance. Spectrometer systems quantified the concentrations of Kr-85m, Kr-87, Kr-88, Kr-89, Kr-90, Xe-131m, Xe-133, Xe 135, Xe 135m, Xe-137, Xe-138, and Xe-139 accumulated over repeated eight hour counting intervals.-. To determine initial fuel quality and fuel performance, release activity for each isotope of interest was derived from FPMS measurements and paired with a calculation of the corresponding isotopic production or birthrate. The release activities and birthrates were combined to determine Release-to-Birth ratios for the selected nuclides. R/B values provide indicators of initial fuel quality and fuel performance during irradiation. This paper presents a brief summary of the FPMS, the release to birth ratio data for the AGR-1 experiment and preliminary comparisons of AGR-1 experimental fuels data to fission gas release models.

  15. Rotating algal biofilm reactor and spool harvester for wastewater treatment with biofuels by-products.

    PubMed

    Christenson, Logan B; Sims, Ronald C

    2012-07-01

    Maximizing algae production in a wastewater treatment process can aid in the reduction of soluble nitrogen and phosphorus concentrations in the wastewater. If harvested, the algae-based biomass offers the added benefit as feedstock for the production of biofuels and bioproducts. However, difficulties in harvesting, concentrating, and dewatering the algae-based biomass have limited the development of an economically feasible treatment and production process. When algae-based biomass is grown as a surface attached biofilm as opposed to a suspended culture, the biomass is naturally concentrated and more easily harvested. This can lead to less expensive removal of the biomass from wastewater, and less expensive downstream processing in the production of biofuels and bioproducts. In this study, a novel rotating algal biofilm reactor (RABR) was designed, built, and tested at bench (8 L), medium (535 L), and pilot (8,000 L) scales. The RABR was designed to operate in the photoautotrophic conditions of open tertiary wastewater treatment, producing mixed culture biofilms made up of algae and bacteria. Growth substrata were evaluated for attachment and biofilm formation, and an effective substratum was discovered. The RABR achieved effective nutrient reduction, with average removal rates of 2.1 and 14.1 g m(-2) day(-1) for total dissolved phosphorus and total dissolved nitrogen, respectively. Biomass production ranged from 5.5 g m(-2) day(-1) at bench scale to as high as 31 g m(-2) day(-1) at pilot scale. An efficient spool harvesting technique was also developed at bench and medium scales to obtain a concentrated product (12-16% solids) suitable for further processing in the production of biofuels and bioproducts. PMID:22328283

  16. ENHANCED HYDROGEN PRODUCTION INTEGRATED WITH CO2 SEPARATION IN A SINGLE-STAGE REACTOR

    SciTech Connect

    Himanshu Gupta; Mahesh Iyer; Bartev Sakadjian; Liang-Shih Fan

    2005-04-01

    Hydrogen production by the water gas shift reaction (WGSR) is equilibrium limited due to thermodynamic constrains. However, this can be overcome by continuously removing the product CO{sub 2}, thereby driving the WGSR in the forward direction to enhance hydrogen production. This project aims at using a high reactivity, mesoporous calcium based sorbent (PCC-CaO) for removing CO{sub 2} using reactive separation scheme. Preliminary results have shown that PCC-CaO dominates in its performance over naturally occurring limestone towards enhanced hydrogen production. However, maintenance of high reactivity of the sorbent over several reaction-regeneration cycles warrants effective regeneration methods. We have identified sub-atmospheric calcination (vacuum) as vital regeneration technique that helps preserve the sorbent morphology. Sub-atmospheric calcination studies reveal the significance of vacuum level, diluent gas flow rate, thermal properties of diluent gas, and sorbent loading on the kinetics of calcination and the morphology of the resultant CaO sorbent. Steam, which can be easily separated from CO{sub 2}, has been envisioned as a potential diluent gas due to its better thermal properties resulting in effective heat transfer. A novel multi-fixed bed reactor was designed which isolates the catalyst bed from the sorbent bed during the calcination step. This should prevent any potential catalyst deactivation due to oxidation by CO{sub 2} during the regeneration phase.

  17. ENHANCED HYDROGEN PRODUCTION INTEGRATED WITH CO2 SEPARATION IN A SINGLE-STAGE REACTOR

    SciTech Connect

    Himanshu Gupta; Mahesh Iyer; Bartev Sakadjian; Liang-Shih Fan

    2005-03-10

    The water gas shift reaction (WGSR) plays a major role in increasing the hydrogen production from fossil fuels. However, the enhanced hydrogen production is limited by thermodynamic constrains posed by equilibrium limitations of WGSR. This project aims at using a mesoporous, tailored, highly reactive calcium based sorbent system for incessantly removing the CO{sub 2} product which drives the equilibrium limited WGSR forward. In addition, a pure sequestration ready CO{sub 2} stream is produced simultaneously. A detailed project vision with the description of integration of this concept with an existing coal gasification process for hydrogen production is presented. Conceptual reactor designs for investigating the simultaneous water gas shift and the CaO carbonation reactions are presented. In addition, the options for conducting in-situ sorbent regeneration under vacuum or steam are also reported. Preliminary, water gas shift reactions using high temperature shift catalyst and without any sorbent confirmed the equilibrium limitation beyond 600 C demonstrating a carbon monoxide conversion of about 80%. From detailed thermodynamic analyses performed for fuel gas streams from typical gasifiers the optimal operating temperature range to prevent CaO hydration and to effect its carbonation is between 575-830 C.

  18. Production and optimization of biodiesel using mixed immobilized biocatalysts in packed bed reactor.

    PubMed

    Bakkiyaraj, S; Syed, Mahin Basha; Devanesan, M G; Thangavelu, Viruthagiri

    2016-05-01

    Vegetable oils are used as raw materials for biodiesel production using transesterification reaction. Several methods for the production of biodiesel were developed using chemical (alkali and acidic compounds) and biological catalysts (lipases). Biodiesel production catalyzed by lipases is energy and cost-saving processes and is carried out at normal temperature and pressure. The need for an efficient method for screening larger number of variables has led to the adoption of statistical experimental design. In the present study, packed bed reactor was designed to study with mixed immobilized biocatalysts to have higher productivity under optimum conditions. Contrary to the single-step acyl migration mechanism, a two-step stepwise reaction mechanism involving immobilized Candida rugosa lipase and immobilized Rhizopus oryzae cells was employed for the present work. This method was chosen because enzymatic hydrolysis followed by esterification can tolerate high free fatty acid containing oils. The effects of flow rate and bed height on biodiesel yield were studied using two factors five-level central composite design (CCD) and response surface methodology (RSM). Maximum biodiesel yield of 85 and 81 % was obtained for jatropha oil and karanja oil with the optimum bed height and optimum flow rate of 32.6 cm and 1.35 L/h, and 32.6 cm and 1.36 L/h, respectively. PMID:25940482

  19. Design and construction of a 7,500 liter immobilized cell reactor-separator for ethanol production from whey

    SciTech Connect

    Dale, M.C.

    1992-12-31

    A 7,500 liter reactor/separator has been constructed for the production of ethanol from concentrated whey permeate. This unit is sited in Hopkinton IA, across the street from a whey generating cheese plant A two phase construction project consisting of (1) building and testing a reactor/separator with a solvent absorber in a single unified housing, and (2) building and testing an extractive distillation/product stripper for the recovery of anhydrous ethanol is under way. The design capacity of this unit is 250,000 gal/yr of anhydrous product. Design and construction details of the reactor/absorber separator are given, and design parameters for the extractive distillation system are described.

  20. A1-U fuel foaming/recriticality considerations for production reactor core-melt accidents

    SciTech Connect

    Cronenberg, A.W. ); Hyder, M.L.; Ellison, P.G. )

    1990-01-01

    Severe accident studies for the Savannah River production reactors indicate that if coherent fuel melting and relocation occur in the absence of target melting, in-vessel recriticality may be achieved. In this paper, fuel-melt/target interaction potential is assessed, where fission gas-induced fuel foaming and melt attach on target material are evaluated and compared with available data. Models are developed to characterize foams for irradiated Al-based fuel. Predictions indicate transient foaming (the extent of which is governed by fission gas inventory), heating transient, and bubble coalescence behavior. The model also indicates that metallic foams are basically unstable and will collapse, which largely depends on film tenacity and melt viscosity. For high-burnup fuel, foams lasting tens of seconds are predicted, allowing molten fuel to contact and cause melt ablation of concentric targets. For low-burnup fuel, contact can not be assured, thus recriticality may be of concern at reactor startup. 8 refs., 4 figs., 4 tabs.

  1. Geologic setting of the New Production Reactor within the Savannah River Site

    SciTech Connect

    Price, V.; Fallaw, W.C.; McKinney, J.B.

    1991-12-31

    The geology and hydrology of the reference New Production Reactor (NPR) site at Savannah River Site (SRS) have been summarized using the available information from the NPR site and areas adjacent to the site, particularly the away from reactor spent fuel storage site (AFR site). Lithologic and geophysical logs from wells drilled near the NPR site do not indicate any faults in the upper several hundred feet of the Coastal Plain sediments. However, the Pen Branch Fault is located about 1 mile south of the site and extends into the upper 100 ft of the Coastal Plain sequence. Subsurface voids, resulting from the dissolution of calcareous portions of the sediments, may be present within 200 ft of the surface at the NPR site. The water table is located within 30 to 70 ft of the surface. The NPR site is located on a groundwater divide, and groundwater flow for the shallowest hydraulic zones is predominantly toward local streams. Groundwater flow in deeper Tertiary sediments is north to Upper Three Runs Creek or west to the Savannah River Swamp. Groundwater flow in the Cretaceous sediments is west to the Savannah River.

  2. Evaluation of radcal gamma thermometers for in-core monitoring of Savannah River Site production reactors

    SciTech Connect

    McCulloch, R.W.; Crowley, J.L. ); Croft, W.D. )

    1991-01-01

    The Savannah River Site (SRS) recently obtained a quantity of Radcal Gamma Thermometer Assemblies (RGTAs) for in-core monitoring of local power in their production reactors. The RGTAs, manufactured by DELTA M Corporation in Oak Ridge, Tennessee, contained seven Self Calibrating Gamma Thermometer (SCGT) sensors within a 7.26 mm diameter, 3.06 m length with a total length of 5.6 m. All RGTAs contained an isolated segmented heater cable for in-situ calibration. Each SCGT sensor was subjected to a 40 point calibration at discrete power levels from 0.5 to 6 watts per gram (w/g) under both joule and cable power. Calibration equations were developed from this to predict reactor power at each sensor. Additionally three units were calibrated at combined joule and cable heating conditions from 0.5 to 2.5 w/g cable and 0.5 to 6 w/g joule. A statistical analysis of all data was used to derive prediction equations that enable SRS engineers to precisely track any changes in sensor calibration throughout the lifetime of the instruments. This paper presents the detailed configuration of the 36 units manufactured for SRS, reviews the calibration results, and discusses the utility and accuracy of the statistically derived prediction equations for in-situ calibration.

  3. Evaluation of radcal gamma thermometers for in-core monitoring of Savannah River Site production reactors

    SciTech Connect

    McCulloch, R.W.; Crowley, J.L.; Croft, W.D.

    1991-12-31

    The Savannah River Site (SRS) recently obtained a quantity of Radcal Gamma Thermometer Assemblies (RGTAs) for in-core monitoring of local power in their production reactors. The RGTAs, manufactured by DELTA M Corporation in Oak Ridge, Tennessee, contained seven Self Calibrating Gamma Thermometer (SCGT) sensors within a 7.26 mm diameter, 3.06 m length with a total length of 5.6 m. All RGTAs contained an isolated segmented heater cable for in-situ calibration. Each SCGT sensor was subjected to a 40 point calibration at discrete power levels from 0.5 to 6 watts per gram (w/g) under both joule and cable power. Calibration equations were developed from this to predict reactor power at each sensor. Additionally three units were calibrated at combined joule and cable heating conditions from 0.5 to 2.5 w/g cable and 0.5 to 6 w/g joule. A statistical analysis of all data was used to derive prediction equations that enable SRS engineers to precisely track any changes in sensor calibration throughout the lifetime of the instruments. This paper presents the detailed configuration of the 36 units manufactured for SRS, reviews the calibration results, and discusses the utility and accuracy of the statistically derived prediction equations for in-situ calibration.

  4. Optimization of a free-fall reactor for the production of fast pyrolysis bio-oil.

    PubMed

    Ellens, C J; Brown, R C

    2012-01-01

    A central composite design of experiments was performed to optimize a free-fall reactor for the production of bio-oil from red oak biomass. The effects of four experimental variables including heater set-point temperature, biomass particle size, sweep gas flow rate and biomass feed rate were studied. Heater set-point temperature ranged from 450 to 650 °C, average biomass particle size from 200 to 600 μm, sweep gas flow rate from 1 to 5 sL/min and biomass feed rate from 1 to 2 kg/h. Optimal operating conditions yielding over 70 wt.% bio-oil were identified at a heater set-point temperature of 575 °C, while feeding red oak biomass sized less than 300 μm at 2 kg/h into the 0.021 m diameter, 1.8m tall reactor. Sweep gas flow rate did not have significant effect on bio-oil yield over the range tested. PMID:22036914

  5. Modification of PROMETHEUS Reactor as a Fusion Breeder and Fission Product Transmuter

    NASA Astrophysics Data System (ADS)

    Yapıcı, Hüseyin; Özışık, Gülşah

    2008-12-01

    This study presents the analyses of the fissile breeding and long-lived fission product (LLFP) transmutation potentials of PROMETHEUS reactor. For this purpose, a fissile breeding zone (FBZ) fueled with the ceramic uranium mono-carbide (UC) and a LLFP transmutation zone (TZ) containing the 99TC and 129I and 135Cs isotopes are separately placed into the breeder zone of PROMETHEUS-H design. The neutronic calculations are performed by using two different computer codes, the XSDRNPM/SCALE4.4a neutron transport code and the MCNP4B Monte Carlo code. A range of analyses are examined to determine the effects of the FF, the fraction of 6Li in lithium (Li) and the theoretical density (TD) of Li2O in the tritium breeder zone (TBZ) on the neutronic parameters. It is observed that the numerical results obtained from both codes are consistent with each other. It is carried out that the profiles of fission power density (FPD) are flattened individually for each FF (from 3 to 10%). Only, in the cases of FF ≥ 8%, the system is self sufficient from the point of view of tritium generation. The results bring out that the modified PROMETHEUS fusion reactor has capabilities of effective fissile breeding and LLFP transmutation, as well as the energy generation.

  6. Ethanol production potential from fermented rice noodle wastewater treatment using entrapped yeast cell sequencing batch reactor

    NASA Astrophysics Data System (ADS)

    Siripattanakul-Ratpukdi, Sumana

    2012-03-01

    Fermented rice noodle production generates a large volume of starch-based wastewater. This study investigated the treatment of the fermented rice noodle wastewater using entrapped cell sequencing batch reactor (ECSBR) compared to traditional sequencing batch reactor (SBR). The yeast cells were applied because of their potential to convert reducing sugar in the wastewater to ethanol. In present study, preliminary treatment by acid hydrolysis was performed. A yeast culture, Saccharomyces cerevisiae, with calcium alginate cell entrapment was used. Optimum yeast cell loading in batch experiment and fermented rice noodle treatment performances using ECSBR and SBR systems were examined. In the first part, it was found that the cell loadings (0.6-2.7 × 108 cells/mL) did not play an important role in this study. Treatment reactions followed the second-order kinetics with the treatment efficiencies of 92-95%. In the second part, the result showed that ECSBR performed better than SBR in both treatment efficiency and system stability perspectives. ECSBR maintained glucose removal of 82.5 ± 10% for 5-cycle treatment while glucose removal by SBR declined from 96 to 40% within the 5-cycle treatment. Scanning electron microscopic images supported the treatment results. A number of yeast cells entrapped and attached onto the matrix grew in the entrapment matrix.

  7. Lagrangian Approach to Jet Mixing and Optimization of the Reactor for Production of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Povitsky, Alex; Salas, Manuel D.

    2001-01-01

    This study was motivated by an attempt to optimize the High Pressure carbon oxide (HiPco) process for the production of carbon nanotubes from gaseous carbon oxide, The goal is to achieve rapid and uniform heating of catalyst particles by an optimal arrangement of jets. A mixed Eulerian and Lagrangian approach is implemented to track the temperature of catalyst particles along their trajectories as a function of time. The FLUENT CFD software with second-order upwind approximation of convective terms and an algebraic multigrid-based solver is used. The poor performance of the original reactor configuration is explained in terms of features of particle trajectories. The trajectories most exposed to the hot jets appear to be the most problematic for heating because they either bend towards the cold jet interior or rotate upwind of the mixing zone. To reduce undesirable slow and/or oscillatory heating of catalyst particles, a reactor configuration with three central jets is proposed and the optimal location of the central and peripheral nozzles is determined.

  8. Determination of production biology of cladocera in a reservoir receiving hyperthermal effluents from a nuclear production reactor. [Par Pond

    SciTech Connect

    Vigerstad, T J

    1980-01-01

    The effects on zooplankton of residence in a cooling reservoir receiving hyperthermal effluents directly from a nuclear-production-reactor were studied. Rates of cladoceran population production were compared at two stations in the winter and summer of 1976 on Par Pond located on the Savannah River Plant, Aiken, SC. One station was located in an area of the reservoir directly receiving hyperthermal effluent (Station MAS) and the second was located about 4 km away in an area where surface temperatures were normal for reservoirs in the general geographical region (Station CAS). A non-parametric comparison between stations of standing stock and fecundity data for Bosmina longirostris, taken for the egg ratio model, was used to observe potential hyperthermal effluent effects. There was a statistically higher incidence of deformed eggs in the Bosmina population at Station MAS in the summer. Bosmina standing stock underwent two large oscillations in the winter and three large oscillations in the summer at Station MAS compared with two in the winter and one in the summer at Station CAS. These results are consistent with almost all other Par Pond studies which have found the two stations to be essentially similar in spectra composition but with some statistically significant differences in various aspects of the biology of the species.

  9. Evaluation of Selected Chemical Processes for Production of Low-cost Silicon, Phase 3. [using a fluidized bed reactor

    NASA Technical Reports Server (NTRS)

    Blocher, J. M., Jr.; Browning, M. F.

    1979-01-01

    The construction and operation of an experimental process system development unit (EPSDU) for the production of granular semiconductor grade silicon by the zinc vapor reduction of silicon tetrachloride in a fluidized bed of seed particles is presented. The construction of the process development unit (PDU) is reported. The PDU consists of four critical units of the EPSDU: the fluidized bed reactor, the reactor by product condenser, the zinc vaporizer, and the electrolytic cell. An experimental wetted wall condenser and its operation are described. Procedures are established for safe handling of SiCl4 leaks and spills from the EPSDU and PDU.

  10. Aluminum/uranium fuel foaming/recriticality considerations for production reactor core-melt accidents

    SciTech Connect

    Hyder, M.L.; Ellison, P.G. ); Cronenberg, A.W. )

    1990-01-01

    Severe accident studies for the Savannah River production reactors indicate that if coherent fuel melting and relocation occur in the absence of target melting, in-vessel recriticality may be achieved. In this paper, fuel-melt/target interaction potential is assessed where fission gas-induced fuel foaming and melt attack on target material are evaluated and compared with available data. Models are developed to characterize foams for irradiated aluminum-based fuel. Predictions indicate transient foaming, the extent of which is governed by fission gas inventory, heating transient conditions, and bubble coalescence behavior. The model also indicates that metallic foams are basically unstable and will collapse, which largely depends on film tenacity and melt viscosity considerations. For high-burnup fuel, extensive foaming lasting tens of seconds is predicted, allowing molten fuel to contact and cause melt ablation of concentric targets. For low-burnup fuel, contact can not be assured. 9 refs., 4 figs., 4 tabs.

  11. Green engineering: continuous production of biodiesel using an alkaline catalyst in an intensified narrow channel reactor.

    PubMed

    Jachuck, R; Pherwani, G; Gorton, S M

    2009-03-01

    This paper describes an energy efficient continuous process for the production of biodiesel using canola oil as feedstock. A narrow channel reactor was used, employing both slug and stratified flow behaviors, which are associated with flow through channels of small hydraulic diameter. In this intensified system, high conversions were achieved and good separation efficiencies were observed. Experiments were carried out using canola oil and methanol as reactants with sodium hydroxide as the catalyst to study the influence of catalyst loading, residence time and temperature on the reaction rate. Using a catalyst loading of 1% and a reaction temperature of 60 degrees C and pressure of 80 psig greater than 98% conversion was achieved in a residence time of 3 min. PMID:19280042

  12. FCC reactor product-catalyst separation: Ten years of commercial experience with closed cyclones

    SciTech Connect

    Miller, R.B.; Johnson, T.E.; Santner, C.R.; Avidan, A.A.; Johnson, D.L.

    1995-09-01

    FCC reactor closed cyclones were first commercialized ten years ago and have now been installed in over 22 FCC units worldwide. Cumulative commercial experience has shown significant yield benefits, in some cases higher than first estimated, and excellent reliability. By nearly eliminating post-riser cracking, they reduce dry gas make and produce higher yields of desirable liquid products. Trouble-free operation with closed cyclones is attributed to proper design, instrumentation, and operating procedures. The Mobil-Kellogg Closed Cyclone technology is the only design offered for license which uses the positive-pressure riser cyclone system which has proven to be least sensitive to upsets. This paper traces the development and commercialization of closed cyclones, discusses differences between competing closed cyclone designs, and documents the benefits which have been observed for Mobil-Kellogg Closed Cyclones.

  13. Analysis of the magnetic corrosion product deposits on a boiling water reactor cladding

    NASA Astrophysics Data System (ADS)

    Orlov, Andrey; Degueldre, Claude; Kaufmann, Wilfried

    2013-01-01

    The buildup of corrosion product deposits (CRUD) on the fuel cladding of the boiling water reactor (BWR) before and after zinc injection has been investigated by applying local experimental analytical techniques. Under the BWR water chemistry conditions, Zn addition together with the presence of Ni and Mn induce the formation of (Zn,Ni,Mn)[Fe2O4] spinel solid solutions. X-ray absorption spectroscopy (XAS) revealed inversion ratios of cation distribution in spinels deposited from the solid solution. Based on this information, a two-site ferrite spinel solid solution model is proposed. Electron probe microanalysis (EPMA) and extended X-ray absorption fine structure (EXAFS) findings suggest the zinc-rich ferrite spinels formation on BWR fuel cladding mainly at lower pin.

  14. Production of Sn-117m in the BR2 and HFIR High-Flux Reactors

    SciTech Connect

    Ponsard, Bernard; Garland, Marc A; Knapp Jr, Russ F; Mirzadeh, Saed; Srivastava, Suresh; Mausner, Leonard

    2008-01-01

    Tin-117m (T 14.0 d; 159 keV, 86%) is a promising radionuclide for therapeutic applications. In contrast to beta emitters, 117mSn emits low-energy conver-sion electrons that deposit their intense energy (127, 129, 152 keV) within a short range (0.22 - 0.29 mm) which can destroy tumors but not damage the bone marrow or other healthy tissues. The 159 keV gamma photons are ideal for imaging to monitor the cancer. This paper reports the results of 117mSn production yield calculations and measurements for several irradiation conditions which can be achieved in both the BR2 (Mol, Belgium) and HFIR (Oak Ridge, USA) High-Flux research reactors.

  15. Consequences of tritium release to water pathways from postulated accidents in a DOE production reactor

    SciTech Connect

    O'Kula, K.R.; Olson, R.L.; Hamby, D.M.

    1991-01-01

    A full-scale PRA of a DOE production reactor has been completed that considers full release of tritium as part of the severe accident source term. Two classes of postulated reactor accidents, a loss-of-moderator pumping accident and a loss-of-coolant accident, are used to bound the expected dose consequence from liquid pathway release. Population doses from the radiological release associated with the two accidents are compared for aqueous discharge and atmospheric release modes. The expectation values of the distribution of possible values for the societal effective dose equivalent to the general public, given a tritium release to the atmosphere, is 2.8 person-Sv/PBq (9.9 {times} 10{sup {minus}3} person-rem/Ci). The general public drinking water dose to downstream water consumers is 6.5 {times} 10{sup {minus}2} person-Sv/Pbq (2.4 {times} 10{sup {minus}4} person-rem/Ci) for aqueous releases to the surface streams eventually reaching the Savannah River. Negligible doses are calculated for freshwater fish and saltwater invertebrate consumption, irrigation, and recreational use of the river, given that an aqueous release is assumed to occur. Relative to the balance of fission products released in a hypothetical severe accident, the tritium-related dose is small. This study suggests that application of regional models (1610 km radius) will indicate larger dose consequences from short-term tritium release to the atmosphere than from comparable tritium source terms to water pathways. However, the water pathways assessment is clearly site-specific, and the overall aqueous dose will be dependent on downstream receptor populations and uses of the river.

  16. Consequences of tritium release to water pathways from postulated accidents in a DOE production reactor

    SciTech Connect

    O`Kula, K.R.; Olson, R.L.; Hamby, D.M.

    1991-12-31

    A full-scale PRA of a DOE production reactor has been completed that considers full release of tritium as part of the severe accident source term. Two classes of postulated reactor accidents, a loss-of-moderator pumping accident and a loss-of-coolant accident, are used to bound the expected dose consequence from liquid pathway release. Population doses from the radiological release associated with the two accidents are compared for aqueous discharge and atmospheric release modes. The expectation values of the distribution of possible values for the societal effective dose equivalent to the general public, given a tritium release to the atmosphere, is 2.8 person-Sv/PBq (9.9 {times} 10{sup {minus}3} person-rem/Ci). The general public drinking water dose to downstream water consumers is 6.5 {times} 10{sup {minus}2} person-Sv/Pbq (2.4 {times} 10{sup {minus}4} person-rem/Ci) for aqueous releases to the surface streams eventually reaching the Savannah River. Negligible doses are calculated for freshwater fish and saltwater invertebrate consumption, irrigation, and recreational use of the river, given that an aqueous release is assumed to occur. Relative to the balance of fission products released in a hypothetical severe accident, the tritium-related dose is small. This study suggests that application of regional models (1610 km radius) will indicate larger dose consequences from short-term tritium release to the atmosphere than from comparable tritium source terms to water pathways. However, the water pathways assessment is clearly site-specific, and the overall aqueous dose will be dependent on downstream receptor populations and uses of the river.

  17. ENHANCED HYDROGEN PRODUCTION INTEGRATED WITH CO2 SEPARATION IN A SINGLE-STAGE REACTOR

    SciTech Connect

    Himanshu Gupta; Mahesh Iyer; Bartev Sakadjian; Liang-Shih Fan

    2005-03-10

    Hydrogen production cannot be maximized from fossil fuels (gas/coal) via the WGS reaction at high temperatures as the WGS-equilibrium constant K{sub WGS} (= [CO{sub 2}][H{sub 2}]/[CO][H{sub 2}O]), falls with increasing temperatures. However, CO{sub 2} removal down to ppm levels by the carbonation of CaO to CaCO{sub 3} in the temperature range 650-850 C, leads to the possibility of stoichiometric H{sub 2} production at high temperature/pressure conditions and at low steam to fuel ratios. Further, CO{sub 2} is also captured in the H{sub 2} generation process, making this coal to hydrogen process compatible with CO{sub 2} sequestration goals. While microporous CaO sorbents attain <50% conversion over cyclical carbonation-calcination, the OSU-patented, mesoporous CaO sorbents are able to achieve >95% conversion. Novel calcination techniques could lead to an ever-smaller footprint, single-stage reactors that achieve maximum theoretical H{sub 2} production at high temperatures and pressures for on/off site usage. Experimental results indicate that the PCC-CaO sorbent is able to achieve complete conversion of CO for 240 seconds as compared to only a few seconds with CaO derived from natural sources.

  18. Treatment of saline wastewaters from marine-products processing factories by activated sludge reactor.

    PubMed

    Khannous, L; Souissi, N; Ghorbel, B; Jarboui, R; Kallel, M; Nasri, M; Gharsallah, N

    2003-10-01

    An activated sludge reactor, operated at room temperature (20-30 degrees C) was used to treat saline wastewaters generated by marine-products industries. The system was operated continuously and the influence of the organic loading rates (OLRs), varying from 250 to 1000 mg COD l(-1) day(-1), on chemical oxygen demand (COD) removal was investigated. The system, inoculated with NaCl-acclimated culture, removed up to 98% and 88% of the influent COD concentrations at OLRs of 250 and 1000 mg COD L(-1) day(-1), respectively. Since the organic pollution is essentially composed of proteins, microorganisms, which produced proteolytic enzymes, were isolated from the activated sludge culture. One bacterium with the highest protease activity, identified as Bacillus cereus, was chosen for protease production in fishery wastewaters of different concentrations containing combined heads and viscera powder. Protease synthesis was strongly enhanced when cells were cultivated in two times diluted fishery wastewaters. The enhancement of protease synthesis could have been due to the presence in effluent of organic matters or salts, which stimulated the growth of the strain and protease production. PMID:14669806

  19. Gluconic acid production from sucrose in an airlift reactor using a multi-enzyme system.

    PubMed

    Mafra, Agnes Cristina Oliveira; Furlan, Felipe Fernando; Badino, Alberto Colli; Tardioli, Paulo Waldir

    2015-04-01

    Sucrose from sugarcane is produced in abundance in Brazil, which provides an opportunity to manufacture other high-value products. Gluconic acid (GA) can be produced by multi-enzyme conversion of sucrose using the enzymes invertase, glucose oxidase, and catalase. In this process, one of the byproducts is fructose, which has many commercial applications. This work concerns the batch mode production of GA in an airlift reactor fed with sucrose as substrate. Evaluation was made of the influence of temperature and pH, as well as the thermal stability of the enzymes. Operational conditions of 40 °C and pH 6.0 were selected, based on the enzymatic activity profiles and the thermal stabilities. Under these conditions, the experimental data could be accurately described by kinetic models. The maximum yield of GA was achieved within 3.8 h, with total conversion of sucrose and glucose and a volumetric productivity of around 7.0 g L(-1) h(-1). PMID:25326720

  20. Computer analyses for the design, operation and safety of new isotope production reactors: A technology status review

    SciTech Connect

    Wulff, W.

    1990-01-01

    A review is presented on the currently available technologies for nuclear reactor analyses by computer. The important distinction is made between traditional computer calculation and advanced computer simulation. Simulation needs are defined to support the design, operation, maintenance and safety of isotope production reactors. Existing methods of computer analyses are categorized in accordance with the type of computer involved in their execution: micro, mini, mainframe and supercomputers. Both general and special-purpose computers are discussed. Major computer codes are described, with regard for their use in analyzing isotope production reactors. It has been determined in this review that conventional systems codes (TRAC, RELAP5, RETRAN, etc.) cannot meet four essential conditions for viable reactor simulation: simulation fidelity, on-line interactive operation with convenient graphics, high simulation speed, and at low cost. These conditions can be met by special-purpose computers (such as the AD100 of ADI), which are specifically designed for high-speed simulation of complex systems. The greatest shortcoming of existing systems codes (TRAC, RELAP5) is their mismatch between very high computational efforts and low simulation fidelity. The drift flux formulation (HIPA) is the viable alternative to the complicated two-fluid model. No existing computer code has the capability of accommodating all important processes in the core geometry of isotope production reactors. Experiments are needed (heat transfer measurements) to provide necessary correlations. It is important for the nuclear community, both in government, industry and universities, to begin to take advantage of modern simulation technologies and equipment. 41 refs.

  1. Fermentative hydrogen production from liquid swine manure with glucose supplement using an anaerobic sequencing batch reactor

    NASA Astrophysics Data System (ADS)

    Wu, Xiao

    2009-12-01

    The idea of coupling renewable energy production and agricultural waste management inspired this thesis. The production of an important future fuel---hydrogen gas---from high strength waste stream-liquid swine manure---using anaerobic treatment processes makes the most sustainable sense for both wastewater utilization and energy generation. The objectives of this thesis were to develop a fermentation process for converting liquid swine manure to hydrogen and to maximize hydrogen productivity. Anaerobic sequencing batch reactor (ASBR) systems were constructed to carry out this fermentation process, and seed sludge obtained from a dairy manure anaerobic digester and pretreated by nutrient acclimation, heat and pH treatment was used as inoculum. High system stability was indicated by a short startup period of 12 days followed by stable hydrogen production, and successful sludge granulation occurred within 23 days of startup at a hydraulic retention time (HRT) of 24 hours. Operation at a progressively decreasing HRT from 24 to 8h gave rise to an increasing biogas production rate from 15.2-34.4L/d, while good linear relationships were observed between both total biogas and hydrogen production rates correlated to HRT, with R2 values of 0.993 and 0.997, respectively. The maximum hydrogen yield of 1.63 mol-H 2/mol-hexose-feed occurred at HRT of 16h, while the HRT of 12h was highly suggested to achieve both high production rate and efficient yield. Hexose utilization efficiencies over 98%, considerable hydrogen production rate up to 14.3 L/d and hydrogen percentage of off-gas up to 43% (i.e., a CO 2/H2 ratio of 1.2) with the absence of CH4 production throughout the whole course of experiment at a pH of 5.0 strongly validated the feasibility of the fermentative H2 production from liquid swine manure using an ASBR system. Ethanol as well as acetic, butyric and valeric acids were produced in the system accompanying the hydrogen production, with acetic acid being the dominant one, which contributed to 56-58% of the total soluble metabolite production, indicative of an acetic acid fermentation system, and acetate-to-butyrate ratio was found to be closely related to hydrogen yield. pH level influenced every aspect of the ASBR performance for hydrogen production. ASBR operation at five pHs ranging from 4.4 to 5.6 (4.4, 4.7, 5.0, 5.3, 5.6) showed distinct dynamic profiles of both biogas production and the changes of H2 and CH4 percentage in the biogas during a running period of 22 days. The H2 content in biogas, H 2 production rate and H2 yield were all pH-dependent, in the range of 5.1-36.9 %, 0.71-8.97 L/d and 0.12-1.50 mol-H2/mol-glucose, respectively, and maximum values for all three responses were simultaneously achieved at pH 5.0. Methanogens appeared to be significantly activated at pH of 5.3 or higher since significant CH4 evolution and concurrent reduction in H2 production was observed at pH 5.3 and 5.6. Acetate, propionate, butyrate, valerate, and ethanol were main aqueous products in all pH tests and their distribution was influenced by pH. Analysis of kinetic models developed from modified Gompertz equations for batch experiments showed that pH had a profound effect on all kinetic parameters for hydrogen production including hydrogen potential, maximum hydrogen production rate and the length of the lag phase, as well as the maximum substrate utilization rate. The low pH of 4.4 gave the highest hydrogen production potential but with the lowest hydrogen production rate. A contrast experiment was conducted with an initial pH of 5.3 but not controlled, came up with a rapid pH decline, leading to a low hexose degradation efficiency of 33.2% and a significantly suppressed H2 production, indicating the importance of pH control and the effect of pH on H2 production and substrate consumption. pH 5.0 was verified as the optimal for the proposed fermentation system by kinetic models. An extremely linear relationship (R2= 0.993) between the maximum H2 production rate and the maximum hexose degradation rate suggested that the pH inhibition on H2 production was a result of the suppression on the bacterial activity for substrate utilization due to an unfavorable pH level. System optimization was realized through experiments conducted according to a response surface methodology, with a central composite design and empirical quadratic response equations obtained for three responses including the hydrogen content in the biogas, hydrogen evolution rate and hydrogen yield, against three independent variables, pH (4.4-5.6), HRT (8-24h) and substrate glucose concentrations (Cg, 0-20 g/L). Contour plots revealed that all three responses were significantly impacted by the variable and squared pH. Furthermore, pH and Cg had a significant interaction effect on H2 production rate, while HRT and glucose concentration were interdependent, or they had a mildly significant interaction effect on H2 production rate. The hydrogen content decreased when pH was greater than 5.0 or less than 4.6 and a largest value of 42.7% could be obtained at pH 4.8, HRT 8 h, and Cg of 18.7 g/L. The highest hydrogen production rate of 26.1 L/d happened under a pH of 4.6, HRT of 8h, and Cg of 20 g/L; Lower HRT and higher Cg was found to benefit the H2 production rate because they provide elevated organic loading and food to microorganism ratio for the system. HRT shorter than 17h resulted in declined hydrogen yield, while the glucose concentration up to 20 g/L did not cause suppression on hydrogen yield. The revised optimal condition of pH 4.8, HRT 11h, and Cg of 20 g/L, which could achieve 85% of the maximum values of all three hydrogen productivity responses, was determined by surface response methodology. Highly reproducible results from confirming experiments at the optimal condition indicated that the results modeled in this study possessed a high reliability, while the results of H2 content, H2 production rate and yield were obtained as 40.3%, 23.16 L/d, and 1.36mol H2/mol hexose, respectively. Results obtained in this study indicated that ASBR system using swine manure based substrate had significant potential of fermentative hydrogen production. Key words: biohydrogen production, hydrogen fermentation, liquid swine manure, anaerobic sequencing batch reactor (ASBR), hydrogen content, hydrogen production rate, hydrogen yield

  2. Separation Requirements for a Hydrogen Production Plant and High-Temperature Nuclear Reactor

    SciTech Connect

    Curtis Smith; Scott Beck; William Galyean

    2006-06-01

    This paper presents an overview of the engineering methods, models, and results used in an evaluation for locating a hydrogen production facility near a proposed next-generation nuclear power plant. Standard probabilistic safety assessment methodologies were used to answer the risk-related questions for a combined nuclear and chemical facility: what can go wrong? how likely is it to happen? and what are the consequences of it happening? As part of answering these questions, a model was developed suitable for determining the distances separating a hydrogen-production process and nuclear plant structures. The objective of the model-development and analysis is to answer key safety questions relating to the placement of one or more hydrogen production plants in the vicinity of a high-temperature nuclear reactor. From a thermal-hydraulic efficiency standpoint, close proximity of the two facilities is beneficial. Safety and regulatory implications, however, force the separation to be increased, perhaps substantially. The likelihood of obtaining a permit to construct and build such as facility in the United States without answering these safety questions is uncertain. The quantitative analysis performed and described in this paper offers a scoping mechanism to determine key parameters relating to the development of a nuclear-based hydrogen production facility. The calculations indicate that when the facilities are less than 100 m apart, the core damage frequency is large enough (greater than 1E-6/yr) to become problematic in a risk-informed environment. However, a variety of design modifications (blast-deflection barriers, for example) could significantly reduce risk and should be further explored as design of the hydrogen production facility evolves.

  3. Organics removal from landfill leachate and activated sludge production in SBR reactors

    SciTech Connect

    Klimiuk, Ewa; Kulikowska, Dorota . E-mail: dorotak@uwm.edu.pl

    2006-07-01

    This study is aimed at estimating organic compounds removal and sludge production in SBR during treatment of landfill leachate. Four series were performed. At each series, experiments were carried out at the hydraulic retention time (HRT) of 12, 6, 3 and 2 d. The series varied in SBR filling strategies, duration of the mixing and aeration phases, and the sludge age. In series 1 and 2 (a short filling period, mixing and aeration phases in the operating cycle), the relationship between organics concentration (COD) in the leachate treated and HRT was pseudo-first-order kinetics. In series 3 (with mixing and aeration phases) and series 4 (only aeration phase) with leachate supplied by means of a peristaltic pump for 4 h of the cycle (filling during reaction period) - this relationship was zero-order kinetics. Activated sludge production expressed as the observed coefficient of biomass production (Y {sub obs}) decreased correspondingly with increasing HRT. The smallest differences between reactors were observed in series 3 in which Y {sub obs} was almost stable (0.55-0.6 mg VSS/mg COD). The elimination of the mixing phase in the cycle (series 4) caused the Y {sub obs} to decrease significantly from 0.32 mg VSS/mg COD at HRT 2 d to 0.04 mg VSS/mg COD at HRT 12 d. The theoretical yield coefficient Y accounted for 0.534 mg VSS/mg COD (series 1) and 0.583 mg VSS/mg COD (series 2). In series 3 and 4, it was almost stable (0.628 mg VSS/mg COD and 0.616 mg VSS/mg COD, respectively). After the elimination of the mixing phase in the operating cycle, the specific biomass decay rate increased from 0.006 d{sup -1} (series 3) to 0.032 d{sup -1} (series 4). The operating conditions employing mixing/aeration or only aeration phases enable regulation of the sludge production. The SBRs operated under aerobic conditions are more favourable at a short hydraulic retention time. At long hydraulic retention time, it can lead to a decrease in biomass concentration in the SBR as a result of cell decay. On the contrary, in the activated sludge at long HRT, a short filling period and operating cycle of the reactor with the mixing and aeration phases seem the most favourable.

  4. Benefit of sodium hydroxide pretreatment of ensiled sorghum forage on the anaerobic reactor stability and methane production.

    PubMed

    Sambusiti, C; Ficara, E; Malpei, F; Steyer, J P; Carrère, H

    2013-09-01

    The assessment of the pretreatment effect on the anaerobic digestion process is generally based on the results of batch tests, which may fail in truly predicting full-scale anaerobic reactors performance. Therefore, in this study, the effect of alkaline pretreatment on the anaerobic digestion of ensiled sorghum forage was evaluated by comparing the results of two semi-continuous CSTR (Continuously Stirred Tank Reactor) anaerobic reactors. Results showed that an alkaline pretreatment step, prior to the anaerobic digestion of ensiled sorghum forage, can have a beneficial effect both in enhancing methane production (an increase of 25% on methane production was observed, if compared to that of untreated sorghum) and in giving more stability to the anaerobic digestion process. PMID:23867533

  5. Measurement of environmental radiation exposure rates from Vernita, Hanford Reach, and Richland area shores. Addendum 1

    SciTech Connect

    Cooper, A.T.

    1995-02-01

    Environmental radiation exposure rate measurements are taken on and around the Hanford Site for Pacific Northwest Laboratory`s Hanford Site Surface Environmental Surveillance Project. In 1992, environmental radiation exposure rate measurements were taken from shoreline and island areas ranging from Vernita, along the Hanford Reach, down to the Richland Pumphouse. Measurements were taken primarily at locations known or expected to have elevated exposure rates as determined by examination of aerial photographs depicting radiation exposure measurements. Results from the 1992 survey indicated radiation exposure rates taken from the Hanford Reach area were elevated in comparison to the measurements taken from the Vernita area with ranges of 8 to 28 {mu}R/hr and 4 to 11 {mu}R/hr, respectively. In January 1994, additional shoreline radiation exposure rate measurements were taken from the Vernita, Hanford Reach, and Richland areas to determine the relationship of radiation exposure rates along the Richland area shores when compared to Vernita and Hanford Reach area exposure rates (measurements along the Richland area were not collected during the 1992 survey). This report discusses the 1994 results and is an addendum to the report that discussed the 1992 survey. An analysis of variance indicated a significant location interaction at a p-value of 0.0014. To determine differences between paried locations a post-hoc comparison of location means was performed on log transformed data using the Scheff{acute e}`s F-test. This test indicated a significant difference between Hanford Reach and Richland area means with a mean difference of 0.075 /{mu}R/hr and a p-value of 0.0014. No significant difference was found between Hanford Reach and Vernita area means: The mean difference was 0.031 {mu}R/hr and the p-value was 0.3138. No significant difference was found between Vernita and Richland area means with a mean difference of 0.044 {mu}R/hr and a p-value of 0.1155.

  6. A Feasibility Study of a Steam Methane Reforming Hydrogen Production Plant with a Sodium-Cooled Fast Reactor

    SciTech Connect

    Chikazawa, Yoshitaka; Konomura, Mamoru; Uchida, Shouji; Sato, Hiroyuki

    2005-12-15

    A thermal source for hydrogen production is an attractive utilization of nuclear energy. Hydrogen production from natural gas is a promising method in an early stage of hydrogen society, though hydrogen production with water splitting without carbon dioxide emission is the final goal. Steam methane reforming is a well-known method for producing hydrogen from natural gas. A hydrogen separation membrane makes the reforming temperature much lower than that of the equilibrium condition, and a sodium-cooled fast reactor, which supplies heat at {approx}500 deg. C, can be used as a heat source for hydrogen production.In this study, a hydrogen production plant with the membrane reforming method using a sodium-cooled reactor as a thermal source has been designed, and its economic potential is roughly evaluated. The hydrogen production cost is estimated to be about $1.67/kg, achieving the economic target of $1.7/kg. The construction cost is largely shared by the reformers' cost, and it can be decreased using a more efficient hydrogen separation membrane. This shows that steam methane reforming hydrogen production with a sodium-cooled reactor has high economical potential.

  7. Feasibility Study of Supercritical Light Water Cooled Reactors for Electrical Power Production, 5th Quarterly Report, October - December 2002

    SciTech Connect

    Philip MacDonald; Jacopo Buongiorno; Cliff Davis; J. Stephen Herring; Kevan Weaver; Ron Latanision; Bryce Mitton; Gary Was; Luca Oriani; Mario Carelli; Dmitry Paramonov; Lawrence Conway

    2003-01-01

    The overall objective of this project is to evaluate the feasibility of supercritical light water cooled reactors for electric power production. The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies for the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If no additional moderator is added to the fuel rod lattice, it is possible to attain fast neutron energy spectrum conditions in a supercritical water-cooled reactor (SCWR). This type of core can make use of either fertile or fertile-free fuel and retain a hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity. One can also add moderation and design a thermal spectrum SCWR that can also burn actinides. The project is organized into three tasks:

  8. Separation Requirements for a Hydrogen Production Plant and High-Temperature Nuclear Reactor

    SciTech Connect

    Curtis Smith; Scott Beck; Bill Galyean

    2005-09-01

    This report provides the methods, models, and results of an evaluation for locating a hydrogen production facility near a nuclear power plant. In order to answer the risk-related questions for this combined nuclear and chemical facility, we utilized standard probabilistic safety assessment methodologies to answer three questions: what can happen, how likely is it, and what are the consequences? As part of answering these questions, we developed a model suitable to determine separation distances for hydrogen process structures and the nuclear plant structures. Our objective of the model-development and analysis is to answer key safety questions related to the placement of one or more hydrogen production plants in the vicinity of a high-temperature nuclear reactor. From a thermal-hydraulic standpoint we would like the two facilities to be quite close. However, safety and regulatory implications force the separation distance to be increased, perhaps substantially. Without answering these safety questions, the likelihood for obtaining a permit to construct and build such as facility in the U.S. would be questionable. The quantitative analysis performed for this report provides us with a scoping mechanism to determine key parameters related to the development of a nuclear-based hydrogen production facility. From our calculations, we estimate that when the separation distance is less than 100m, the core damage frequency is large enough (greater than 1E-6/yr) to become problematic in a risk-informed environment. However, a variety of design modifications, for example blast-deflection barriers, were explored to determine the impact of potential mitigating strategies. We found that these mitigating cases may significantly reduce risk and should be explored as the design for the hydrogen production facility evolves.

  9. Safety Issues at the Defense Production Reactors. A Report to the U.S. Department of Energy.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Commission on Physical Sciences, Mathematics, and Resources.

    This report provides an assessment of safety management, safety review, and safety methodology employed by the Department of Energy (DOE) and private contractors. Chapter 1, "The DOE Safety Framework," examines safety objectives for production reactors and processes to implement the objectives. Chapter 2, "Technical Issues," focuses on a variety…

  10. Combined production and purification of hydrogen from methanol using steam iron process in fixed bed reactor

    NASA Astrophysics Data System (ADS)

    Campo, R.; Durán, P.; Plou, J.; Herguido, J.; Peña, J. A.

    2013-11-01

    A research work is being conducted to study the combined production and purification of hydrogen by means of redox processes departing from biomass fast pyrolysis oils (bio-oils). To achieve that goal, methanol has been used as featured material because it is the most representative compound of the alcoholic fraction of bio-oils. The study has been carried out in a fixed bed reactor where methanol decomposes in H2 and CO when gets in contact with a reactive solid based in an iron oxide at temperatures above 600 °C. During the first stage of the “steam-iron” process, reactive gases reduce the iron oxide to metallic iron. Afterward, in a following step, the previously reduced iron is reoxidized by steam producing a high purity hydrogen stream. Although coke deposition does exist during the reducing stage, this behaves as inert during the reoxidation process. Coke inert role has been corroborated by GC, SEM and TEM techniques, showing that carbon deposits were constituted by ordered structures (carbon nanotubes). The determination of the hydrogen production along successive cycles allowed the evaluation of the effect of temperature and alternating reactive atmospheres on the stability of the solid, as well as the optimum conditions for such purpose.

  11. Optimization of a whole-cell biocatalyst by employing genetically encoded product sensors inside nanolitre reactors.

    PubMed

    Meyer, Andreas; Pellaux, René; Potot, Sébastien; Becker, Katja; Hohmann, Hans-Peter; Panke, Sven; Held, Martin

    2015-08-01

    Microcompartmentalization offers a high-throughput method for screening large numbers of biocatalysts generated from genetic libraries. Here we present a microcompartmentalization protocol for benchmarking the performance of whole-cell biocatalysts. Gel capsules served as nanolitre reactors (nLRs) for the cultivation and analysis of a library of Bacillus subtilis biocatalysts. The B. subtilis cells, which were co-confined with E. coli sensor cells inside the nLRs, converted the starting material cellobiose into the industrial product vitamin B2. Product formation triggered a sequence of reactions in the sensor cells: (1) conversion of B2 into flavin mononucleotide (FMN), (2) binding of FMN by a RNA riboswitch and (3) self-cleavage of RNA, which resulted in (4) the synthesis of a green fluorescent protein (GFP). The intensity of GFP fluorescence was then used to isolate B. subtilis variants that convert cellobiose into vitamin B2 with elevated efficiency. The underlying design principles of the assay are general and enable the development of similar protocols, which ultimately will speed up the optimization of whole-cell biocatalysts. PMID:26201745

  12. Optimization of a whole-cell biocatalyst by employing genetically encoded product sensors inside nanolitre reactors

    NASA Astrophysics Data System (ADS)

    Meyer, Andreas; Pellaux, René; Potot, Sébastien; Becker, Katja; Hohmann, Hans-Peter; Panke, Sven; Held, Martin

    2015-08-01

    Microcompartmentalization offers a high-throughput method for screening large numbers of biocatalysts generated from genetic libraries. Here we present a microcompartmentalization protocol for benchmarking the performance of whole-cell biocatalysts. Gel capsules served as nanolitre reactors (nLRs) for the cultivation and analysis of a library of Bacillus subtilis biocatalysts. The B. subtilis cells, which were co-confined with E. coli sensor cells inside the nLRs, converted the starting material cellobiose into the industrial product vitamin B2. Product formation triggered a sequence of reactions in the sensor cells: (1) conversion of B2 into flavin mononucleotide (FMN), (2) binding of FMN by a RNA riboswitch and (3) self-cleavage of RNA, which resulted in (4) the synthesis of a green fluorescent protein (GFP). The intensity of GFP fluorescence was then used to isolate B. subtilis variants that convert cellobiose into vitamin B2 with elevated efficiency. The underlying design principles of the assay are general and enable the development of similar protocols, which ultimately will speed up the optimization of whole-cell biocatalysts.

  13. Co-composting of eggshell waste in self-heating reactors: monitoring and end product quality.

    PubMed

    Soares, Micaela A R; Quina, Margarida M J; Quinta-Ferreira, Rosa M

    2013-11-01

    Industrial eggshell waste (ES) is classified as an animal by-product not intended to human consumption. For reducing pathogen spreading risk due to soil incorporation of ES, sanitation by composting is a pre-treatment option. This work aims to evaluate eggshell waste recycling in self-heating composting reactors and investigate ES effect on process evolution and end product quality. Potato peel, grass clippings and rice husks were the starting organic materials considered. The incorporation of 30% (w/w) ES in a composting mixture did not affect mixture biodegradability, nor its capacity to reach sanitizing temperatures. After 25 days of composting, ES addition caused a nitrogen loss of about 10 g N kg(-1) of initial volatile solids, thus reducing nitrogen nutritional potential of the finished compost. This study showed that a composting mixture with a significant proportion of ES (30% w/w) may be converted into calcium-rich marketable compost to neutralize soil acidity and/or calcium deficiencies. PMID:24055972

  14. Production and physicochemical properties of functional-butterfat through enzymatic interesterification in a continuous reactor.

    PubMed

    Shin, Jung-Ah; Akoh, Casimir C; Lee, Ki-Teak

    2009-02-11

    Modified-butterfat (MBF) was synthesized with four blends (8:6:6, 6:6:8, 6:6:9, and 4:6:10, by weight) of anhydrous butterfat (ABF), palm stearin (PS) and flaxseed oil (FSO) through enzymatic interesterification in a continuous packed-bed reactor. Flow rate effect of 3, 5, 8 and 10 mL/min on enzymatic interesterification was investigated. By increasing the enzyme contact time with substrates (decreased flow rates), not only did melting and crystallization points shift to lower temperature but also the equivalent carbon number, ECN 36-38 from FSO decreased. Further all reactions were performed at flow rate of 5 mL/min (contact time 140 min) in a continuous reactor packed with 150 g of Lipozyme RM IM. After short path distillation, alpha-linolenic acid composition (%) of 8:6:6, 6:6:8, 6:6:9, and 4:6:10 MBFs were 16, 21, 23 and 25%, respectively. The contents of ECN 36-38, and ECN 48-50 decreased in the blends and MBFs for each substrate ratio. ECN 42-46 in the newly produced TAG increased. Melting points of MBFs were 38 degrees C (8:6:6), 35.5 degrees C (6:6:8), 34 degrees C (6:6:9), and 32 degrees C (4:6:10). MBFs interesterified with FSO contained phytosterols (17-36 mg/100 g) and tocopherols (116-173 microg/g). The products of 8:6:6, 6:6:8, 6:6:9 and 4:6:10 MBFs were softer (69, 88, 80, and 92%, respectively) than pure butterfat at refrigeration temperature. The polymorphic form changed from beta form (blends) to desirable crystalline structure of beta' form (MBFs). Crystal morphology of MBFs also changed and was composed of small spherulites of varying density. PMID:19138078

  15. Radioactive Fission Product Release from Defective Light Water Reactor Fuel Elements

    SciTech Connect

    Konyashov, Vadim V.; Krasnov, Alexander M.

    2002-04-15

    Results are provided of the experimental investigation of radioactive fission product (RFP) release, i.e., krypton, xenon, and iodine radionuclides from fuel elements with initial defects during long-term (3 to 5 yr) irradiation under low linear power (5 to 12 kW/m) and during special experiments in the VK-50 vessel-type boiling water reactor.The calculation model for the RFP release from the fuel-to-cladding gap of the defective fuel element into coolant was developed. It takes into account the convective transport in the fuel-to-cladding gap and RFP sorption on the internal cladding surface and is in good agreement with the available experimental data. An approximate analytical solution of the transport equation is given. The calculation dependencies of the RFP release coefficients on the main parameters such as defect size, fuel-to-cladding gap, temperature of the internal cladding surface, and radioactive decay constant were analyzed.It is shown that the change of the RFP release from the fuel elements with the initial defects during long-term irradiation is, mainly, caused by fuel swelling followed by reduction of the fuel-to-cladding gap and the fuel temperature. The calculation model for the RFP release from defective fuel elements applicable to light water reactors (LWRs) was developed. It takes into account the change of the defective fuel element parameters during long-term irradiation. The calculation error according to the program does not exceed 30% over all the linear power change range of the LWR fuel elements (from 5 to 26 kW/m)

  16. Letter report: Title listing of daily operating data on Hanford single-pass reactors, 1944--1971. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Gydesen, S.P.

    1992-02-01

    The primary objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation dose that populations and individuals could have received as a result of emissions from Hanford Site operations since 1944, with descriptions of the uncertainties inherent in such estimates. A secondary objective is to make project documentation and Hanford-originated references used in the reports available to the public. Hanford-originated documents of potential interest and/or use to the HEDR Project are made publicly available through the US Government`s National Technical Information Service and placed in the US Department of Energy Richland Field Office (RL) Public Reading Room in Richland, Washington. Project work is conducted under several technical tasks, among which is the Source Terms Task. Under this task, estimates of radioactive emissions from Hanford facilities since 1944 are developed. These estimates are based on historical measurements and production information. The Information Resources Task identifies and retrieves historical production operating information for developing source terms. The purpose of this letter report is to identify documents that record daily reactor operating information at the Hanford Site for the years 1944--1971. Complete bibliographic citations and sample pages from each different format for Hanford reactor operations data are included.

  17. Alternative Energy Saving Technology Analysis Report for Richland High School Renovation Project

    SciTech Connect

    Liu, Bing

    2004-08-09

    On July 8, 2004, L&S Engineering, Inc. submitted a technical assistance request to Pacific Northwest National Laboratory (PNNL) to help estimate the potential energy savings and cost effectiveness of the solar energy and daylighting design alternatives for Richland High School Renovation Project in Richland, WA. L&S Engineering expected PNNL to evaluate the potential energy savings and energy cost savings, the probable installation costs, incentives or grants to reduce the installed costs and simple payback for the following alternative measures: (1) Daylighting in New Gym; (2) Solar Photovoltaics; (3) Solar Domestic Hot Water Pre-Heat; and (4) Solar Outside Air Pre-Heat Following are the findings of the energy savings and cost-effectiveness analysis of above alternative energy saving technologies.

  18. ESTABLISHING FINAL END STATE FOR A RETIRED NUCLEAR WEAPONS PRODUCTION REACTOR; COLLABORATION BETWEEN STAKEHOLDERS, REGULATORS AND THE FEDERAL GOVERNMENT

    SciTech Connect

    Bergren, C

    2009-01-16

    The Savannah River Site (SRS) is a 310-square-mile United States Department of Energy nuclear facility located along the Savannah River (SRS) near Aiken, South Carolina. Nuclear weapons material production began in the early 1950s, utilizing five production reactors. In the early 1990s all SRS production reactor operations were terminated. The first reactor closure end state declaration was recently institutionalized in a Comprehensive Environmental Response and Compensation and Liability Act (CERCLA) Early Action Record of Decision. The decision for the final closure of the 318,000 square foot 105-P Reactor was determined to be in situ decommissioning (ISD). ISD is an acceptable and cost effective alternative to off-site disposal for the reactor building, which will allow for consolidation of remedial action wastes generated from other cleanup activities within the P Area. ISD is considered protective by the regulators, U. S. Environmental Protection Agency (US EPA) and the South Carolina Department of Health and Environmental Control (SCDHEC), public and stakeholders as waste materials are stabilized/immobilized, and radioactivity is allowed to naturally decay, thus preventing future exposure to the environment. Stakeholder buy-in was critical in the upfront planning in order to achieve this monumental final decision. Numerous public meetings and workshops were held in two different states (covering a 200 mile radius) with stakeholder and SRS Citizens Advisory Board participation. These meetings were conducted over an eight month period as the end state decision making progressed. Information provided to the public evolved from workshop to workshop as data became available and public input from the public meetings were gathered. ISD is being considered for the balance of the four SRS reactors and other hardened facilities such as the chemical processing canyons.

  19. ESTABLISHING FINAL END STATE FOR A RETIRED NUCLEAR WEAPONS PRODUCTION REACTOR; COLLABORATION BETWEEN STAKEHOLDERS, REGULATORS, AND THE FEDERAL GOVERNMENT - 11052

    SciTech Connect

    Bergren, C.; Flora, M.; Belencan, H.

    2010-11-17

    The Savannah River Site (SRS) is a 310-square-mile United States Department of Energy nuclear facility located along the Savannah River (SRS) near Aiken, South Carolina. Nuclear weapons material production began in the early 1950s, utilizing five production reactors. In the early 1990s all SRS production reactor operations were terminated. The first reactor closure end state declaration was recently institutionalized in a Comprehensive Environmental Response and Compensation and Liability Act (CERCLA) Early Action Record of Decision. The decision for the final closure of the 318,000 square foot 105-P Reactor was determined to be in situ decommissioning (ISD). ISD is an acceptable and cost effective alternative to off-site disposal for the reactor building, which will allow for consolidation of remedial action wastes generated from other cleanup activities within the P Area. ISD is considered protective by the regulators, U. S. Environmental Protection Agency (US EPA) and the South Carolina Department of Health and Environmental Control (SCDHEC), public and stakeholders as waste materials are stabilized/immobilized, and radioactivity is allowed to naturally decay, thus preventing future exposure to the environment. Stakeholder buy-in was critical in the upfront planning in order to achieve this monumental final decision. Numerous public meetings and workshops were held in two different states (covering a 200 mile radius) with stakeholder and SRS Citizens Advisory Board participation. These meetings were conducted over an eight month period as the end state decision making progressed. Information provided to the public evolved from workshop to workshop as data became available and public input from the public meetings were gathered. ISD is being considered for the balance of the four SRS reactors and other hardened facilities such as the chemical Separation Facilities (canyons).

  20. Environmental Assessment Use of Existing Borrow Areas, Hanford Site, Richland, Washington

    SciTech Connect

    N /A

    2001-10-10

    The U.S. Department of Energy (DOE) operates the Hanford Site near Richland, Washington. The DOE needs to identify and operate onsite locations for a continued supply of raw aggregate materials [approximately 7,600,000 cubic meters (10,000,000 cubic yards) over the next 10 years] for new facility construction, maintenance of existing facilities and transportation corridors, and fill and capping material for remediation and other sites.

  1. Evaluating Carriers for Immobilizing Saccharomyces cerevisiae for Ethanol Production in a Continuous Column Reactor

    PubMed Central

    Cha, Hye-Geun; Kim, Yi-Ok; Choi, Woon Yong; Kang, Do-Hyung; Lee, Hyeon-Yong

    2014-01-01

    We evaluated a more practical and cost-effective immobilization carriers for ethanol production using the yeast Saccharomyces cerevisiae. Three candidate materials-rice hull, rice straw, and sawdust-were tested for their cell-adsorption capacity and operational durability. Derivatizations of rice hull, rice straw, and sawdust with the optimal concentration of 0.5 M of 2-(diethylamino)ethyl chloride hydrochloride (DEAE · HCl) resulted in > 95% adsorption of the initial yeast cells at 2 hr for DEAE-rice hull and DEAE-sawdust and in only approximately 80% adsorption for DEAE-rice straw. In addition, DEAE-sawdust was found to be a more practical carrier for immobilizing yeast cells in terms of operational durability in shaking flask cultures with two different speeds of 60 and 150 rpm. Furthermore, the biosorption isotherms of DEAE-rice hull, -rice straw, and -sawdust for yeast cells revealed that the Qmax of DEAE-sawdust (82.6 mg/g) was greater than that of DEAE-rice hull and DEAE-rice straw. During the 404-hr of continuous column reactor operation using yeast cells immobilized on DEAE-sawdust, no serious detachment of the yeast cells from the DEAE-sawdust was recorded. Ethanol yield of approximately 3.04 g/L was produced steadily, and glucose was completely converted to ethanol at a yield of 0.375 g-ethanol/g-glucose (73.4% of the theoretical value). Thus, sawdust is a promising practical immobilization carrier for ethanol production, with significance in the production of bioethanol as a biofuel. PMID:25346601

  2. Syngas Production By Thermochemical Conversion Of H2o And Co2 Mixtures Using A Novel Reactor Design

    SciTech Connect

    Pearlman, Howard; Chen, Chien-Hua

    2014-08-27

    The Department of Energy awarded Advanced Cooling Technologies, Inc. (ACT) an SBIR Phase II contract (#DE-SC0004729) to develop a high-temperature solar thermochemical reactor for syngas production using water and/or carbon dioxide as feedstocks. The technology aims to provide a renewable and sustainable alternative to fossil fuels, promote energy independence and mitigate adverse issues associated with climate change by essentially recycling carbon from carbon dioxide emitted by the combustion of hydrocarbon fuels. To commercialize the technology and drive down the cost of solar fuels, new advances are needed in materials development and reactor design, both of which are integral elements in this program.

  3. Superfund record of decision (EPA Region 4): Palmetto Recycling, Inc., operable unit 1, Richland County, Columbia, SC, March 30, 1995

    SciTech Connect

    1995-04-01

    This decision document presents the selected remedial action for the Palmetto Recycling Superfund Site (the Site), located in Columbia, Richland County, South Carolina. This remedial action addresses surface soil contamination.

  4. FABRICATION PROCESS AND PRODUCT QUALITY IMPROVEMENTS IN ADVANCED GAS REACTOR UCO KERNELS

    SciTech Connect

    Charles M Barnes

    2008-09-01

    A major element of the Advanced Gas Reactor (AGR) program is developing fuel fabrication processes to produce high quality uranium-containing kernels, TRISO-coated particles and fuel compacts needed for planned irradiation tests. The goals of the AGR program also include developing the fabrication technology to mass produce this fuel at low cost. Kernels for the first AGR test (“AGR-1) consisted of uranium oxycarbide (UCO) microspheres that werre produced by an internal gelation process followed by high temperature steps tot convert the UO3 + C “green” microspheres to first UO2 + C and then UO2 + UCx. The high temperature steps also densified the kernels. Babcock and Wilcox (B&W) fabricated UCO kernels for the AGR-1 irradiation experiment, which went into the Advance Test Reactor (ATR) at Idaho National Laboratory in December 2006. An evaluation of the kernel process following AGR-1 kernel production led to several recommendations to improve the fabrication process. These recommendations included testing alternative methods of dispersing carbon during broth preparation, evaluating the method of broth mixing, optimizing the broth chemistry, optimizing sintering conditions, and demonstrating fabrication of larger diameter UCO kernels needed for the second AGR irradiation test. Based on these recommendations and requirements, a test program was defined and performed. Certain portions of the test program were performed by Oak Ridge National Laboratory (ORNL), while tests at larger scale were performed by B&W. The tests at B&W have demonstrated improvements in both kernel properties and process operation. Changes in the form of carbon black used and the method of mixing the carbon prior to forming kernels led to improvements in the phase distribution in the sintered kernels, greater consistency in kernel properties, a reduction in forming run time, and simplifications to the forming process. Process parameter variation tests in both forming and sintering steps led to an increased understanding of the acceptable ranges for process parameters and additional reduction in required operating times. Another result of this test program was to double the kernel production rate. Following the development tests, approximately 40 kg of natural uranium UCO kernels have been produced for use in coater scale up tests, and approximately 10 kg of low enriched uranium UCO kernels for use in the AGR-2 experiment.

  5. Corrosion product deposits on boiling-water reactor cladding: Experimental and theoretical investigation of magnetic properties

    NASA Astrophysics Data System (ADS)

    Orlov, A.; Degueldre, C.; Wiese, H.; Ledergerber, G.; Valizadeh, S.

    2011-09-01

    Recent Eddy current investigations on the cladding of nuclear fuel pins have shown that the apparent oxide layers are falsified due to unexpected magnetic properties of corrosion product deposits. Analyses by Scanning Electron Microscopy (SEM) or Electron Probe Micro Analysis (EPMA) demonstrated that the deposit layer consists of complex 3-d element oxides (Ni, Mn, Fe) along with Zn, since the reactor operates with a Zn addition procedure to reduce buildup of radiation fields on the recirculation system surfaces. The oxides crystallise in ferritic spinel structures. These spinels are well-known for their magnetic behaviour. Since non-magnetic zinc ferrite (ZnFe 2O 4) may become magnetic when doped with even small amounts of Ni and/or Mn, their occurrence in the deposit layer has been analyzed. The magnetic permeability of zinc ferrite, trevorite and jacobsite and their solid solutions are estimated by magnetic moment additivity. From the void history examination, the low elevation sample (810 mm) did not face significant boiling during the irradiation cycles suggesting growth of (Mn0.092+Zn0.752+Fe0.293+)[(Fe1.713+Mn0.032+Ni0.132+)O] crystals with theoretical value of the magnetic permeability for the averaged heterogeneous CRUD layer of 9.5 ± 3. Meanwhile, (Mn0.162+Zn0.552+Fe0.293+)[(Fe1.713+Mn0.042+Ni0.252+)O] crystallizes at the mid elevation (1810 mm) with theoretical magnetic permeability for the CRUD layer of 4.2 ± 1.5 at the investigated azimuthal location. These theoretical data are compared with the magnetic permeability of the corrosion product deposited layers gained from reactor pool side Eddy current (EC) analyses (9.0 ± 1.0 for low and 3.5 ± 1.0 for high elevation). The calculated thicknesses and magnetic permeability values of the deposition layers (estimated by MAGNACROX multifrequency EC method) match together with these estimated using an "ion magnetic moment additivity" model.

  6. Continuous methane fermentation and the production of vitamin B12 in a fixed-bed reactor packed with loofah.

    PubMed

    Yang, Yingnan; Zhang, Zhenya; Lu, Jun; Maekawa, Takaaki

    2004-05-01

    A fixed-bed reactor with acclimated methanogens immobilized on a loofah support was studied on a laboratory scale to evaluate the system producing methane from the mixture of CO(2) and H(2) gas, with the production of vitamin B(12) as a by-product. Fermentation using CO(2)/H(2) acclimated methanogens was conducted in a jar fermentor with hydraulic retention times (HRTs) of three and six days. The performance of the reactor was mainly dependent on the HRT. With an HRT of three days, the methane production rate and the vitamin B(12) concentration in the culture broth were 6.18 l/l-reactor/h and 2.88 mg/l-culture liquid; these values were 11.96 l/l-reactor/h and 37.54 mg/l-culture liquid for an HRT of six days. A higher total cell mass of methanogens retained 42.5 g dry cell/l-culture liquid was achieved in the HRT of six days. The loofah carrier immobilized almost 95% of the methanogens, which led to a more effective bio-reaction. It was also observed that the fermentation system had a better ability to buffer pH, especially for an HRT of six days. PMID:14766162

  7. Beneficial synergetic effect on gas production during co-pyrolysis of sewage sludge and biomass in a vacuum reactor.

    PubMed

    Zhang, Weijiang; Yuan, Chengyong; Xu, Jiao; Yang, Xiao

    2015-05-01

    A vacuum fixed bed reactor was used to pyrolyze sewage sludge, biomass (rice husk) and their blend under high temperature (900°C). Pyrolytic products were kept in the vacuum reactor during the whole pyrolysis process, guaranteeing a long contact time (more than 2h) for their interactions. Remarkable synergetic effect on gas production was observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The syngas (CO and H2) content and gas lower heating value (LHV) were obviously improved as well. It was highly possible that sewage sludge provided more CO2 and H2O during co-pyrolysis, promoting intense CO2-char and H2O-char gasification, which benefited the increase of gas yield and lower heating value. The beneficial synergetic effect, as a result, made this method a feasible one for gas production. PMID:25728344

  8. Dual-mode cultivation of Chlorella protothecoides applying inter-reactors gas transfer improves microalgae biodiesel production.

    PubMed

    Santos, C A; Nobre, B; Lopes da Silva, T; Pinheiro, H M; Reis, A

    2014-08-20

    Chlorella protothecoides, a lipid-producing microalga, was grown heterotrophically and autotrophically in separate reactors, the off-gases exiting the former being used to aerate the latter. Autotrophic biomass productivity with the two-reactor association, 0.0249gL(-1)h(-1), was 2.2-fold the value obtained in a control autotrophic culture, aerated with ambient air. Fatty acid productivity was 1.7-fold the control value. C. protothecoides heterotrophic biomass productivity was 0.229gL(-1)h(-1). This biomass' fatty acid content was 34.5% (w/w) with a profile suitable for biodiesel production, according to European Standards. The carbon dioxide fixed by the autotrophic biomass was 45mgCO2L(-1)h(-1) in the symbiotic arrangement, 2.1 times the control reactor value. The avoided CO2 atmospheric emission represented 30% of the CO2 produced in the heterotrophic stage, while the released O2 represented 49% of the oxygen demand in that stage. Thus, an increased efficiency in the glucose carbon source use and a higher environmental sustainability were achieved in microalgal biodiesel production using the proposed assembly. PMID:24862195

  9. Hybrid adsorptive membrane reactor

    DOEpatents

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  10. Hybrid adsorptive membrane reactor

    NASA Technical Reports Server (NTRS)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  11. Performance of co-immobilized yeast and glucoamylase in a fluidized bed reactor for fuel ethanol production

    SciTech Connect

    Sun, M.Y.; Bienkowski, P.R.; Davison, B.H. |; Spurrier, M.A.; Webb, O.F.

    1996-07-01

    The performance of co-immobilized Saccharomyces cerevisiae and glucoamylase was evaluated in a fluidized bed reactor. Soluble starch and yeast extract were used as feed stocks. The biocatalyst performed well and demonstrated no significant loss of activity or physical integrity during 10 weeks of continuous operation. The reactor was easily operated and required no pH control. No operational problems were encountered from bacterial contaminants even though the reactor was operated under non-sterile conditions over the entire course of experiments. Productivities ranged between 25 to 44 g ethanol L{sup -1} h{sup -1}. The experiments demonstrated that ethanol inhibition and bed loading had significant effects on bed performance.

  12. Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Dominguez, Jesus A.

    2012-01-01

    The technology of direct electrolysis of molten lunar regolith to produce oxygen and molten metal alloys has progressed greatly in the last few years. The development of long-lasting inert anodes and cathode designs as well as techniques for the removal of molten products from the reactor has been demonstrated. The containment of chemically aggressive oxide and metal melts is very difficult at the operating temperatures ca. 1600 C. Containing the molten oxides in a regolith shell can solve this technical issue and can be achieved by designing a Joule-heated (sometimes called 'self-heating') reactor in which the electrolytic currents generate enough Joule heat to create a molten bath. Solutions obtained by multiphysics modeling allow the identification of the critical dimensions of concept reactors.

  13. Ethanol production during semi-continuous syngas fermentation in a trickle bed reactor using Clostridium ragsdalei.

    PubMed

    Devarapalli, Mamatha; Atiyeh, Hasan K; Phillips, John R; Lewis, Randy S; Huhnke, Raymond L

    2016-06-01

    An efficient syngas fermentation bioreactor provides a mass transfer capability that matches the intrinsic kinetics of the microorganism to obtain high gas conversion efficiency and productivity. In this study, mass transfer and gas utilization efficiencies of a trickle bed reactor during syngas fermentation by Clostridium ragsdalei were evaluated at various gas and liquid flow rates. Fermentations were performed using a syngas mixture of 38% CO, 28.5% CO2, 28.5% H2 and 5% N2, by volume. Results showed that increasing the gas flow rate from 2.3 to 4.6sccm increased the CO uptake rate by 76% and decreased the H2 uptake rate by 51% up to Run R6. Biofilm formation after R6 increased cells activity with over threefold increase in H2 uptake rate. At 1662h, the final ethanol and acetic acid concentrations were 5.7 and 12.3g/L, respectively, at 200ml/min of liquid flow rate and 4.6sccm gas flow rate. PMID:26950756

  14. An investigation of sulfate production in clouds using a flow-through chemical reactor model approach

    NASA Technical Reports Server (NTRS)

    Hong, M. S.; Carmichael, G. R.

    1983-01-01

    A flow-through chemical reactor model is developed to describe the mass transfer and chemical processes that atmospheric gases undergo in clouds. The model includes the simultaneous absorption of SO2, NH3, O3, NO(x), HNO3, CO2 and H2O2, the accompanying dissociation and oxidation reactions in cloud water, considers electrical neutrality, and includes qualitative parameterization of cloud microphysics. The model is used to assess the importance of the oxidation reactions H2O2-S(IV), O3-S(IV), and S(IV)-Mn(2+) catalysis, and the effects of cloud parameters such as drop size, rain intensity, liquid water content, and updraft velocity. Both precipitating and nonprecipitating clouds are studied. Model results predict sulfate production rates varying from 3 percent/hr to 230 percent/hr. The actual rate is highly dependent on the chemical composition of the uptake air and the physical conditions of the cloud. Model results also show that both the H2O2 and the O3 oxidation reactions can be significant.

  15. Test of an anaerobic prototype reactor coupled with a filtration unit for production of VFAs.

    PubMed

    Poughon, Laurent; Creuly, Catherine; Farges, Bérangère; Dussap, Claude-Gilles; Schiettecatte, Wim; Jovetic, Srdjan; De Wever, Heleen

    2013-10-01

    The artificial ecosystem MELiSSA, supported by the European Space Agency is a closed loop system consisting of 5 compartments in which food, water and oxygen are produced out of organic waste. The first compartment is conceived as a thermophilic anaerobic membrane bioreactor liquefying organic waste into VFAs, ammonium and CO2 without methane. A 20 L reactor was assembled to demonstrate the selected design and process at prototype scale. We characterized system performance from start-up to steady state and evaluated process efficiencies with special attention drawn to the mass balances. An overall efficiency for organic matter biodegradation of 50% was achieved. The dry matter content was stabilized around 40-50 g L(-1) and VFA production around 5-6 g L(-1). The results were consistent for the considered substrate mixture and can also be considered relevant in a broader context, as a first processing step to produce building blocks for synthesis of primary energy vectors. PMID:23333084

  16. Fission product iodine release and retention in nuclear reactor accidents— experimental programme at PSI

    NASA Astrophysics Data System (ADS)

    Bruchertseifer, H.; Cripps, R.; Guentay, S.; Jaeckel, B.

    2003-01-01

    Iodine radionuclides constitute one of the most important fission products of uranium and plutonium. If the volatile forms would be released into the environment during a severe accident, a potential health hazard would then ensue. Understanding its behaviour is an important prerequisite for planning appropriate mitigation measures. Improved and extensive knowledge of the main iodine species and their reactions important for the release and retention processes in the reactor containment is thus mandatory. The aim of PSI's radiolytical studies is to improve the current thermodynamic and kinetic databases and the models for iodine used in severe accident computer codes. Formation of sparingly soluble silver iodide (AgI) in a PWR containment sump can substantially reduce volatile iodine fraction in the containment atmosphere. However, the effectiveness is dependent on its radiation stability. The direct radiolytic decomposition of AgI and the effect of impurities on iodine volatilisation were experimentally determined at PSI using a remote-controlled and automated high activity 188W/Re generator (40 GBq/ml). Low molecular weight organic iodides are difficult to be retained in engineered safety systems. Investigation of radiolytic decomposition of methyl iodide in aqueous solutions, combined with an on-line analysis of iodine species is currently under investigation at PSI.

  17. Optimization of irradiation conditions for {sup 177}Lu production at the LVR-15 research reactor

    SciTech Connect

    Lahodova, Z.; Viererbl, L.; Klupak, V.; Srank, J.

    2012-07-01

    The use of lutetium in medicine has been increasing over the last few years. The {sup 177}Lu radionuclide is commercially available for research and test purposes as a diagnostic and radiotherapy agent in the treatment of several malignant tumours. The yield of {sup 177}Lu from the {sup 176}Lu(n,{gamma}){sup 177}Lu nuclear reaction depends significantly on the thermal neutron fluence rate. The capture cross-sections of both reaction {sup 176}Lu(n,{gamma}){sup 177}Lu and reaction {sup 177}Lu(n,{gamma}){sup 178}Lu are very high. Therefore a burn-up of target and product nuclides should be taken into account when calculating {sup 177}Lu activity. The maximum irradiation time, when the activity of the {sup 177}Lu radionuclide begins to decline, was found for different fluence rates. Two vertical irradiation channels at the LVR-15 nuclear research reactor were compared in order to choose the channel with better irradiation conditions, such as a higher thermal neutron fluence rate in the irradiation volume. In this experiment, lutetium was irradiated in a titanium capsule. The influence of the Ti capsule on the neutron spectrum was monitored using activation detectors. The choice of detectors was based on requirements for irradiation time and accurate determination of thermal neutrons. The following activation detectors were selected for measurement of the neutron spectrum: Ti, Fe, Ni, Co, Ag and W. (authors)

  18. The decommissioning of the graphite moderated production reactors at the U.S. Department of Energy`s Hanford Site

    SciTech Connect

    Spence, S.T.

    1993-12-31

    The approximately 1,450 km{sup 2} Hanford Site in Southeastern Washington State was commissioned for the production of special nuclear materials by the Manhattan District of the Army Corps of Engineering in 1943. Eight graphite-moderated, water-cooled reactors were constructed in five self-supporting complexes between 1943 and 1955. These reactors and their ancillary structures have been declared surplus and are in the process of being decommissioned by the US Department of Energy (DOE) and its contractors. The eight retired Hanford reactors will form the largest reactor decommissioning project undertaken anywhere in the world. However, numerous smaller facilities have been, or are currently being, decommissioned in the US and throughout the world. Additionally, through technology exchange, the DOE is building its base of decommissioning knowledge from projects currently underway in France, Germany, Japan, the United Kingdom, and others, while sharing the DOE`s experience with these same foreign governments. This paper describes the eight reactors to be decommissioned, the alternatives, cost and schedules, estimated radiation exposure, and the experience leading up to this project.

  19. Investigation on a corrosion product deposit layer on a boiling water reactor fuel cladding

    NASA Astrophysics Data System (ADS)

    Orlov, A. V.; Restani, R.; Kuri, G.; Degueldre, C.; Valizadeh, S.

    2010-02-01

    Recent investigations on the complex corrosion product deposits on a boiling water reactor (BWR) fuel cladding have shown that the observed layer locally presents unexpected magnetic properties. The magnetic behaviour of this layer and its axial variation on BWR fuel cladding is of interest with respect to non-destructive cladding characterization. Consequently, a cladding from a BWR was cut at elevations of 810 mm, where the layer was observed to be magnetic, and of 1810 mm where it was less magnetic. The samples were subsequently analyzed using electron probe microanalysis (EPMA), magnetic analysis and X-ray techniques (μXRF, μXRD and μXAFS). Both EPMA and μXRF have shown that the observed corrosion deposit layer which is situated on the Zircaloy corrosion layer consists mostly of 3-d elements' oxides (Fe, Zn, Ni and Mn). The distribution of these elements within the investigated layer is rather complex and not homogeneous. The main phases identified by 2D μXRD mapping inside the layer are hematite and spinel phases with the common formula M xFe y(M (1-x)Fe (2-y))O 4, where M = Zn, Ni, Mn. It has been shown that the solid solutions of these phases were obtained with rather large differences between the parameter cell of the known spinels (ZnFe 2O 4, NiFe 2O 4 and MnFe 2O 4) and the investigated material. The comparison of EPMA with μXRD analysis shows that the ratio of Fe 2O 3/MFe 2O 4 (M = Zn, Ni, Mn) phases in the lower sample equals ˜1/2 and in the higher one ˜1/1 within the analyzed volume of the samples. It has been shown that this ratio, together with the thickness of the corrosion product deposit layer, effect its magnetic properties.

  20. Production of Advanced Biofuels via Liquefaction - Hydrothermal Liquefaction Reactor Design: April 5, 2013

    SciTech Connect

    Knorr, D.; Lukas, J.; Schoen, P.

    2013-11-01

    This report provides detailed reactor designs and capital costs, and operating cost estimates for the hydrothermal liquefaction reactor system, used for biomass-to-biofuels conversion, under development at Pacific Northwest National Laboratory. Five cases were developed and the costs associated with all cases ranged from $22 MM/year - $47 MM/year.

  1. Nuclear Reactors. Revised.

    ERIC Educational Resources Information Center

    Hogerton, John F.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: How Reactors Work; Reactor Design; Research, Teaching, and Materials Testing; Reactors (Research, Teaching and Materials); Production Reactors; Reactors for Electric Power…

  2. Mesophilic hydrogen production in acidogenic packed-bed reactors (APBR) using raw sugarcane vinasse as substrate: Influence of support materials.

    PubMed

    Nunes Ferraz Júnior, Antônio Djalma; Etchebehere, Claudia; Zaiat, Marcelo

    2015-08-01

    Bio-hydrogen production from sugarcane vinasse in anaerobic up-flow packed-bed reactors (APBR) was evaluated. Four types of support materials, expanded clay (EC), charcoal (Ch), porous ceramic (PC), and low-density polyethylene (LDP) were tested as support for biomass attachment. APBR (working volume - 2.3 L) were operated in parallel at a hydraulic retention time of 24 h, an organic loading rate of 36.2 kg-COD m(-3) d(-1), at 25 °C. Maximum volumetric hydrogen production values of 509.5, 404, 81.4 and 10.3 mL-H2 d(-1) L(-1)reactor and maximum yields of 3.2, 2.6, 0.4 and 0.05 mol-H2 mol(-1) carbohydrates total, were observed during the monitoring of the reactors filled with LDP, EC, Ch and PC, respectively. Thus, indicating the strong influence of the support material on H2 production. LDP was the most appropriate material for hydrogen production among the materials evaluated. 16S rRNA gene by Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis and scanning electron microscopy confirmed the selection of different microbial populations. 454-pyrosequencing performed on samples from APBR filled with LDP revealed the presence of hydrogen-producing organisms (Clostridium and Pectinatus), lactic acid bacteria and non-fermentative organisms. PMID:25891935

  3. [Interview]: Alexandre Shvartsburg, Pacific Northwest National Laboratory, Richland, WA, USA

    SciTech Connect

    Shvartsburg, Alexandre A.

    2012-12-01

    Q1. What are your main research activities in ion mobility mass spectrometry (past or present)? My early efforts focused on the structural characterization of atomic (carbon and semiconductor) clusters. After the production of bulk fullerenes, many hoped that other nanoclusters discovered in the gas phase could also coalesce into new materials. As these studies required accurate and robust mobility calculations for any ion geometry, I strived to build the needed theory and implement it in the Mobcal software widely employed today. Since 2004, I have been developing methods and novel applications of differential IMS (FAIMS) at PNNL. The principal achievement has been raising the resolving power by over tenfold (up to ~400 for multiply-charged peptides) using elevated fields, helium and hydrogen-rich buffers, and extended filtering times. This performance broadly allows previously unthinkable separations of very similar species, for example sequence inversions and post-translational modification localization isomers of peptides (including “middle-down” peptides such as histone tails), lipid regioisomers, and even isotopomers. Another major direction is investigating the dipole alignment of larger proteins, which creates an exceptionally strong FAIMS effect that is a potential tool for structural biology. Q2: What have been the most significant instrumentation or applications developments in the history of ion mobility - mass spectrometry? In 1995 when I started graduate research at Northwestern, only two groups worldwide worked with IMS/MS and “the literature” meant papers by Bowers (UCSB). Well-wishers counseled me to “learn something useful like HPLC, as IMS would never have real utility”. This booklet showcases the scale of change since. First, the practical IMS/ToF platforms for complex biological analyses demonstrated by Clemmer have turned IMS/MS from an esoteric physical chemistry technique into a powerful analytical tool. By commercializing the IMS/ToF technology in Synapt instruments, Waters has greatly increased its impact via expanded number and diversity of applications. Concurrently, Guevremont at Canadian NRC has perfected FAIMS coupled to MS, deployed it for real-world bio and environmental analyses, and widely distributed it in the Ionalytics Selectra system (subsequently installed on Thermo MS platforms). The latest breakthrough is ultra-FAIMS by Owlstone, where extreme fields allow numerous qualitatively new separations and operational modes that we just begin to explore. Q3: Where do you see ion mobility - mass spectrometry making the most impact in the next 5 years? Any predictions for where the field will go? Sciences dealing with perturbations in media (such as optics or acoustics) at some point shift from the linear to nonlinear paradigm, where propagation depends on the magnitude of perturbation or its driving force. While the linear part remains industrially important (e.g., eyewear and architectural glass for optics), frontline research moves to nonlinear phenomena. IMS is undergoing that transition now with the rise of FAIMS, which should continue as the fundamental understanding improves, new modalities and applications emerge, and more instrumentation is introduced by vendors. Modifying and augmenting FAIMS separations through vapor dopants that render ion mobilities less linear is becoming routine. I expect this area to advance, extending to more specific interactions and to complexation with solution additives. Another route to higher separation power is integrating FAIMS with conventional IMS; proliferation of both technologies would make such 2-D platforms common. Along with mass spectrometry and conventional IMS, FAIMS will address increasingly large macromolecules, including proteins and their complexes.

  4. Basic energy efficiency of plasma production in electrical discharge and electron beam reactors

    SciTech Connect

    Penetrante, B.M.; Hsiao, M.C.; Bardsley, J.N.; Merritt, B.T.; Vogtlin, G.E.; Kuthi, A.; Burkhart, C.P.; Bayless, J.R.

    1996-11-01

    Non-thermal plasma processing is an emerging technology for the abatement of volatile organic compounds (VOCs) and nitrogen oxides (NO{sub x}) in atmospheric pressure gas streams. Either electrical discharge of electron beam methods can produce these plasmas. This paper presents a comparative assessment of various non-thermal plasma reactors. The goal of our project is two-fold: (1) to understand the feasibility and scalability of various non-thermal plasma reactors by focusing on the energy efficiency of the electron and chemical kinetics, and (2) to optimize process parameters and provide performance and economic data. Experimental results using a compact electron beam reactor, pulsed corona reactor and dielectric-barrier discharge will be presented. These reactors have been used to study the removal of NO{sub x} and a wide variety of VOCs. The effects of background gas decomposition and gas temperature on the decomposition chemistry have been studied. The decomposition mechanisms are discussed to illustrate how the chemistry could strongly affect the economics of the process. An analysis of the electron kinetics show that electrical discharge reactors are the most suitable only for processes requiring O radicals. For pollution control applications requiring copious amounts of electrons, ions, N atoms or OH radicals, the sue of electron beam reactors is generally the best way of minimizing the electrical power consumption.

  5. Correlation between hydroxyl radical production and theoretical pressure distribution in a sonochemical reactor

    NASA Astrophysics Data System (ADS)

    Martnez-Tarifa, A.; Arrojo, S.; Louisnard, O.; Gonzlez-Garca, Jos; Tudela, I.

    2010-01-01

    The effects of operational parameters upon the hydroxyl radical generation of sonochemical reactors are critical to optimize this technology for wastewater treatment purposes. Ultrasonic wave characteristics are usually considered as the main parameter to be taken into account. Nevertheless, it is the interaction of these waves with the liquid medium and the reactor what really affects the process. Therefore, the characterization of sonochemical reactors should be based on the effective pressure distribution in the reactor, which not only includes the wave characteristics but also the propagation and reflection of these ultrasonic oscillations. The pressure field can be characterized using different parameters, such as maximum pressure amplitude or volumetric integration of pressure in the reactor. This study intends to find a correlation between such calculated pressure-distribution-related parameters and experimental measurements of hydroxyl radicals in the process. Both experiments and calculations are run varying the tip-bottom distance (keeping the rest of parameters constant), creating different reflection effects with the reactor walls and therefore different pressure distributions across the reactor. The hydroxyl radical measurements are performed with salicylic acid dosimetry, applying a specific developed method for biphasic cavitating systems. On the other hand, the pressure distribution was calculated simulating the different configurations with the computational tool COMSOL.

  6. Thermodynamics of vaporization of fission products and materials under severe reactor accident conditions: Analysis of molten core/concrete chemistry

    NASA Astrophysics Data System (ADS)

    Cubicciotti, Daniel

    1985-02-01

    Vaporization-condensation processes can generate radioactive aerosols in the event of a core dryout and meltdown accident at a nuclear power station. The time sequence of fission produce vaporization and aerosol formation in relation to processes that can transport them out of the reactor containment is important for assessing their potential biohazard. Thermodynamics of vaporization of fission products and other materials are evaluated for the extreme environmental conditions projected by computer models if a molten core penetrates the reactor vessel and melts into the concrete base. A free energy minimization treatment was used to estimate partial pressures of gases in this many-component, multiphase system. The amounts of fission products and condensable materials vaporized were calculated for a test case involving basalt-aggregate concrete.

  7. Fast Pyrolysis of Poplar Using a Captive Sample Reactor: Effects of Inorganic Salts on Primary Pyrolysis Products

    SciTech Connect

    Mukarakate, C.; Robichaud, D.; Donohoe, B.; Jarvis, M.; Mino, K.; Bahng, M. K.; Nimlos, M.

    2012-01-01

    We have constructed a captive sample reactor (CSR) to study fast pyrolysis of biomass. The reactor uses a stainless steel wire mesh to surround biomass materials with an isothermal environment by independent controlling of heating rates and pyrolysis temperatures. The vapors produced during pyrolysis are immediately entrained and transported in He carrier gas to a molecular beam mass spectrometer (MBMS). Formation of secondary products is minimized by rapidly quenching the sample support with liquid nitrogen. A range of alkali and alkaline earth metal (AAEM) and transition metal salts were tested to study their effect on composition of primary pyrolysis products. Multivariate curve resolution (MCR) analysis of the MBMS data shows that transition metal salts enhance pyrolysis of carbohydrates and AAEM salts enhances pyrolysis of lignin. This was supported by performing similar separate studies on cellulose, hemicellulose and extracted lignin. The effect of salts on char formation is also discussed.

  8. High velocity continuous-flow reactor for the production of solar grade silicon

    NASA Technical Reports Server (NTRS)

    Woerner, L.

    1977-01-01

    The feasibility of a high volume, high velocity continuous reduction reactor as an economical means of producing solar grade silicon was tested. Bromosilanes and hydrogen were used as the feedstocks for the reactor along with preheated silicon particles which function both as nucleation and deposition sites. A complete reactor system was designed and fabricated. Initial preheating studies have shown the stability of tetrabromosilane to being heated as well as the ability to preheat hydrogen to the desired temperature range. Several test runs were made and some silicon was obtained from runs carried out at temperatures in excess of 1180 K.

  9. The Hanford Site New Production Reactor (NPR) economic and demographic baseline forecasts

    SciTech Connect

    Cluett, C.; Clark, D.C. ); Pittenger, D.B. )

    1990-08-01

    The objective of this is to present baseline employment and population forecasts for Benton, Franklin, and Yakima Counties. These forecasts will be used in the socioeconomic analysis portion of the New Production Reactor Environmental Impact Statement. Aggregate population figures for the three counties in the study area were developed for high- and low-growth scenarios for the study period 1990 through 2040. Age-sex distributions for the three counties during the study period are also presented. The high and low scenarios were developed using high and low employment projections for the Hanford site. Hanford site employment figures were used as input for the HARC-REMI Economic and Demographic (HED) model to produced baseline employment forecasts for the three counties. These results, in turn, provided input to an integrated three-county demographic model. This model, a fairly standard cohort-component model, formalizes the relationship between employment and migration by using migration to equilibrate differences in labor supply and demand. In the resulting population estimates, age-sex distributions for 1981 show the relatively large work force age groups in Benton County while Yakima County reflects higher proportions of the population in the retirement ages. The 2040 forecasts for all three counties reflect the age effects of relatively constant and low fertility increased longevity, as well as the cumulative effects of the migration assumptions in the model. By 2040 the baby boom population will be 75 years and older, contributing to the higher proportion of population in the upper end age group. The low scenario age composition effects are similar. 13 refs., 5 figs., 9 tabs.

  10. Effect of sulfate addition on methane production and sulfate reduction in a mesophilic acetate-fed anaerobic reactor.

    PubMed

    Yang, Sen-Lin; Tang, Yue-Qin; Gou, Min; Jiang, Xia

    2015-04-01

    A mesophilic anaerobic moving bed biofilm reactor (MBBR) was operated to evaluate the effect of sulfate addition on methane production and sulfate reduction using acetate as the sole carbon source. The results show that at the organic loading rate of 4.0 g TOC/L/day, the TOC removal efficiencies and the biogas production rates achieved over 95 % and 7000 mL/L/day without sulfate, respectively, and slightly decreased with sulfate addition (500-800 mg/L). Methane production capacities were not influenced significantly with the addition of sulfate, while sulfate reduction efficiencies were not stable with 23-87 % in the acetate-fed reactor. Fluorescent in situ hybridization (FISH) was used to analyze the functional microbial compositions of acetate-degrading methane-producing bacteria (MPB) and sulfate-reducing bacteria (SRB) in the reactor. The results found that as the increase of sulfate concentration, the proportion of Methanomicrobiales increased up to 58 ± 2 %, while Methanosaeta and Methanosarcina decreased. The dominant methanogens shifted into hydrogenotrophic methanogens from even distribution of acetoclastic and hydrogenotrophic methanogens. When hydrogenotrophic methanogens were dominant, sulfate reduction efficiency was high, while sulfate reduction efficiency was low as acetoclastic methanogens were dominant. PMID:25427678

  11. NATIVE Column Ozone Measurements Over Richland, WA During INTEX-B and Comparisons With OMI Satellite Retrievals

    NASA Astrophysics Data System (ADS)

    Taubman, B.; Hui, J.; Thompson, A.; Clothiaux, E.; Labow, G.; Krotkov, N.

    2007-12-01

    The Nittany Atmospheric Trailer and Integrated Validation Experiment (NATIVE, http://www.meteo.psu.edu/~btaubman/Webpage/native.html) was deployed in Richland, WA from April 21, 2006 through May 15, 2006 for INTEX-B (Intercontinental Chemical Transport Experiment, http://www.espo.nasa.gov/intex-b/). Column and vertical profile ozone measurements were made using daily ozonesonde launches, a Microtops sunphotometer, and a UV shadowband radiometer. These measurements were compared with Aura Ozone Monitoring Instrument (OMI) total column ozone (TCO) derived using the DOAS and TOMS 8 retrieval algorithms and the tropospheric ozone residual (TOR) derived by subtracting the Microwave Limb Sounder (MLS) stratospheric column ozone (SCO) from the TCO. The sonde derived TCO, TOR, and SCO data were generally greater than the satellite products when using the same dynamically defined tropopause heights. The shadowband radiometer TCO values were highly dependent on the solar irradiance values at the top of the atmosphere estimated using Langley regressions as well as the assumed ozone absorption coefficients. The DOAS derived TCO values were generally greater than those using the TOMS 8 algorithm, but the opposite was true when cloud cover exceeded 0.2. Steep horizontal ozone gradients in the upper troposphere, the result of high amplitude Rossby wave propagation over the region, also created discrepancies among the different instruments.

  12. Preliminary risks associated with postulated tritium release from production reactor operation

    SciTech Connect

    O'Kula, K.R.; Horton, W.H.

    1988-09-01

    The Probabilistic Risk Assessment (PRA) of Savannah River Plant (SRP) reactor operation is evaluating the offsite risk due to tritium releases during postulated full or partial loss of heavy water moderator accidents. Preliminary determination of the frequency of average partial moderator loss (including incidents with leaks as small as 0.5 kg) yields an estimate of --1 per reactor-year. The full moderator loss frequency is conservatively chosen as 5x10/sup -3/ per reactor-year. Conditional consequences, determined with a version of the MACCS code modified to handle tritium, are found to be insignificant. The 95th percentile individual cancer risk is 2x10/sup -8/ per reactor-year within 16 km of the release point. The full moderator loss accident contributes about 80% of the evaluated risks.

  13. Vented target elements for use in an isotope-production reactor. [LMFBR

    DOEpatents

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium gas in a fast breeder reactor cooled with liquid metal. Lithium target material is placed in pins equipped with vents, and tritium gas is recovered from the coolant.

  14. Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power Production

    SciTech Connect

    Philip MacDonald; Jacopo Buongiorno; James Sterbentz; Cliff Davis; Robert Witt; Gary Was; J. McKinley; S. Teysseyre; Luca Oriani; Vefa Kucukboyaci; Lawrence Conway; N. Jonsson: Bin Liu

    2005-02-13

    The supercritical water reactor (SCWR) has been the object of interest throughout the nuclear Generation IV community because of its high potential: a simple, direct cycle, compact configuration; elimination of many traditional LWR components, operation at coolant temperatures much higher than traditional LWRs and thus high thermal efficiency. It could be said that the SWR was viewed as the water counterpart to the high temperature gas reactor.

  15. Final report on LDRD project : biodiesel production from vegetable oils using slit-channel reactors.

    SciTech Connect

    Kalu, E. Eric; Chen, Ken Shuang

    2008-01-01

    This report documents work done for a late-start LDRD project, which was carried out during the last quarter of FY07. The objective of this project was to experimentally explore the feasibility of converting vegetable (e.g., soybean) oils to biodiesel by employing slit-channel reactors and solid catalysts. We first designed and fabricated several slit-channel reactors with varying channel depths, and employed them to investigate the improved performance of slit-channel reactors over traditional batch reactors using a NaOH liquid catalyst. We then evaluated the effectiveness of several solid catalysts, including CaO, ZnO, MgO, ZrO{sub 2}, calcium gluconate, and heteropolyacid or HPA (Cs{sub 2.5}H{sub 0.5}PW{sub 12}O{sub 40}), for catalyzing the soybean oil-to-biodiesel transesterification reaction. We found that the slit-channel reactor performance improves as channel depth decreases, as expected; and the conversion efficiency of a slit-channel reactor is significantly higher when its channel is very shallow. We further confirmed CaO as having the highest catalytic activity among the solid catalysts tested, and we demonstrated for the first time calcium gluconate as a promising solid catalyst for converting soybean oil to biodiesel, based on our preliminary batch-mode conversion experiments.

  16. A monolithic lipase reactor for biodiesel production by transesterification of triacylglycerides into fatty acid methyl esters

    PubMed Central

    Urban, Jiri; Svec, Frantisek; Fréchet, Jean M.J.

    2011-01-01

    An enzymatic reactor with lipase immobilized on a monolithic polymer support has been prepared and used to catalyze the transesterification of triacylglycerides into the fatty acid methyl esters commonly used for biodiesel. A design of experiments procedure was used to optimize the monolithic reactor with variables including control of the surface polarity of the monolith via variations in the length of the hydrocarbon chain in alkyl methacrylate monomer, time of grafting of 1-vinyl-4,4-dimethylazlactone used to activate the monolith, and time used for the immobilization of porcine lipase. Optimal conditions involved the use of a poly(stearyl methacrylate-co-ethylene dimethacrylate) monolith, grafted first with vinylazlactone, then treated with lipase for 2 h to carry out the immobilization of the enzyme. Best conditions for the transesterification of glyceryl tributyrate included a temperature of 37°C and a 10 min residence time of the substrate in the bioreactor. The reactor did not lose its activity even after pumping through it a solution of substrate equaling 1,000 reactor volumes. This enzymatic reactor was also used for the transesterification of triacylglycerides from soybean oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. PMID:21915852

  17. Thermal- and Fast-Spectrum Molten Salt Reactors for Actinide Burning and Fuel Production

    SciTech Connect

    Forsberg, Charles W

    2007-01-01

    In a molten salt reactor (MSR), the fuel is dissolved in a fluoride salt coolant. The technology was partly developed in the 1950s and 1960s. With changing goals for advanced reactors and new technologies, there is currently a renewed interest in MSRs. The new technologies include (1) Brayton power cycles (rather than steam cycles) that eliminate many of the historical challenges in building MSRs and (2) the conceptual development of several fast-spectrum MSRs that have large negative temperature and void coefficients, a unique safety characteristic not found in solid-fuel fast reactors. Earlier MSRs were thermal-neutron-spectrum reactors. Compared with solid-fueled reactors, MSR systems have lower fissile inventories, no radiation damage constraint on attainable fuel burnup, no spent nuclear fuel, no requirement to fabricate and handle solid fuel, and a single isotopic composition of fuel in the reactor. These and other characteristics may enable MSRs to have potentially unique capabilities and competitive economics for actinide burning and extending fuel resources. The status, unique characteristics, and recent worldwide advances in MSRs are described.

  18. Thermal- and fast-spectrum molten salt reactors for actinide burning and fuel production

    SciTech Connect

    Forsberg, Charles W.

    2007-07-01

    In a molten salt reactor (MSR), the fuel is dissolved in a fluoride salt coolant. The technology was partly developed in the 1950's and 1960's. With changing goals for advanced reactors and new technologies, there is currently a renewed interest in MSRs. The new technologies include (1) Brayton power cycles (rather than steam cycles) that eliminate many of the historical challenges in building MSRs and (2) the conceptual development of several fast-spectrum MSRs that have large negative temperature and void coefficients, a unique safety characteristic not found in solid-fuel fast reactors. Earlier MSRs were thermal-neutron-spectrum reactors. Compared with solid-fueled reactors, MSR systems have lower fissile inventories, no radiation damage constraint on attainable fuel burnup, no spent nuclear fuel, no requirement to fabricate and handle solid fuel, and a single isotopic composition of fuel in the reactor. These and other characteristics may enable MSRs to have potentially unique capabilities and competitive economics for actinide burning and extending fuel resources. The status, unique characteristics, and recent worldwide advances in MSRs are described. (author)

  19. Effect of bone on the pyrolysis product distribution and composition in a fixed bed reactor

    NASA Astrophysics Data System (ADS)

    Alhassan, M.; Andresen, J. M.

    2012-04-01

    Co-pyrolysis of Biomass including Pistachio shell (PS), Pine wood (PW) and Wheat Straw (WS) with Bone matter (BM) have been investigated to determine the effect of bone on the quality of bio-char and bio-oil produced. The aim of this study is to generate stable and nitrogen enriched bio-char that can act as fertilizer while at the same time optimizes the chemical stability of the char to act as a Carbon Capture and Storage system (CCS) and co-produce high quality oils for renewable energy generation. To achieve this, the present study has focused on the influence of bone matter addition from 0wt% to 25wt% to the biomasses in a fixed bed pyrolysis reactor at 3000C. The analysis of the char products shows that the addition of bone to the biomass increased their char yields up to 10wt% addition. Higher addition was found to reduce the overall char yield from the biomass. At 10wt% bone addition, the carbon, hydrogen, and nitrogen content, and the gross calorific value of the chars were increased by 7wt%, 29wt%, 163wt% and 19Mj/kg, for Wheat straw, 62wt%, 46wt%, 135wt%, 110Mj/kg for Pine wood and 7wt%, 76wt%, 42wt% and 33Mj/kg for Pistachio shells. The oxygen content of the Wheat straw, Pistachio shells and pine wood mixed with 10wt% BM decreased by 28wt%, 21wt%, and 93wt%, respectively. The bio-oil yield increased for the bone addition up to 5%wt% for all the samples, its energy value and concentration of its major chemical components was improved for fuel and pharmaceutical use. Port experiment has shown that plant grown on soil amended with the bio-char produced gave higher yield as compared to that from un-amended soil. Comparison between the three biomasses investigated showed similar pattern of change. Hence it can be concluded that at optimum addition of bone to the biomass, bio-chars and oil yield could be optimized for soil amendment, energy production, while retaining carbon for sequestration.

  20. Simple automatic device for real time sampling of gas production by a reactor

    SciTech Connect

    Frattolillo, A.

    2006-06-15

    An innovative automatic device, allowing periodically drawing samples of the gases produced by a generic reactor, is presented. The gases evolving during the reaction are collected in a storage manifold, equipped with a variable volume consisting of a stainless steel bellow, whose expansion or contraction is driven by a linear step motor. A capacitive gauge monitors the pressure inside the storage manifold, while a feedback control loop reacts to any pressure change adjusting the variable volume (by means of the step motor) in such a way to keep the pressure at a desired set point P{sub 0}. As long as the reaction proceeds, the gas production results in a progressive expansion of the variable volume, whose instantaneous value is constantly monitored by means of a slide potentiometer, whose lever is rigidly connected to the bellow's moving extremity. Once the bellow's expansion has reached a predetermined volume increment {delta}V, which means that an amount of gas P{sub 0}{delta}V has been produced and collected in the storage circuit, a quantity P{sub 0}V{sub S}{<=}P{sub 0}{delta}V of gas is released to the analysis system. A set of electropneumatic valves, automatically operated by the control system, allows for gas delivery to the analysis equipment and retrieval of the set point pressure, by compression of the variable volume, with no influence on the reaction. All relevant parameters are monitored and logged on a personal computer. The control and data acquisition software, made out using National Instrument LABVIEW trade mark sign , also provides control of the analysis equipment. The ability of the proposed setup to not affect the ongoing process allows real time monitoring (by drawing samples at regular time intervals during the reaction) of the gas production. Moreover, since the amount of gas P{sub 0}V{sub S} drawn at each sampling is always the same, it is possible to establish at a glance whether or not there are changes in the concentration of any component, by directly comparing the results of the analysis of successive samples.

  1. Simple automatic device for real time sampling of gas production by a reactor

    NASA Astrophysics Data System (ADS)

    Frattolillo, A.

    2006-06-01

    An innovative automatic device, allowing periodically drawing samples of the gases produced by a generic reactor, is presented. The gases evolving during the reaction are collected in a storage manifold, equipped with a variable volume consisting of a stainless steel bellow, whose expansion or contraction is driven by a linear step motor. A capacitive gauge monitors the pressure inside the storage manifold, while a feedback control loop reacts to any pressure change adjusting the variable volume (by means of the step motor) in such a way to keep the pressure at a desired set point P0. As long as the reaction proceeds, the gas production results in a progressive expansion of the variable volume, whose instantaneous value is constantly monitored by means of a slide potentiometer, whose lever is rigidly connected to the bellow's moving extremity. Once the bellow's expansion has reached a predetermined volume increment ΔV, which means that an amount of gas P0ΔV has been produced and collected in the storage circuit, a quantity P0VS⩽P0ΔV of gas is released to the analysis system. A set of electropneumatic valves, automatically operated by the control system, allows for gas delivery to the analysis equipment and retrieval of the set point pressure, by compression of the variable volume, with no influence on the reaction. All relevant parameters are monitored and logged on a personal computer. The control and data acquisition software, made out using National Instrument LABVIEW™, also provides control of the analysis equipment. The ability of the proposed setup to not affect the ongoing process allows real time monitoring (by drawing samples at regular time intervals during the reaction) of the gas production. Moreover, since the amount of gas P0VS drawn at each sampling is always the same, it is possible to establish at a glance whether or not there are changes in the concentration of any component, by directly comparing the results of the analysis of successive samples.

  2. Removal of Total Coliforms, Thermotolerant Coliforms, and Helminth Eggs in Swine Production Wastewater Treated in Anaerobic and Aerobic Reactors

    PubMed Central

    Zacarias Sylvestre, Silvia Helena; Lux Hoppe, Estevam Guilherme; de Oliveira, Roberto Alves

    2014-01-01

    The present work evaluated the performance of two treatment systems in reducing indicators of biological contamination in swine production wastewater. System I consisted of two upflow anaerobic sludge blanket (UASB) reactors, with 510 and 209 L in volume, being serially arranged. System II consisted of a UASB reactor, anaerobic filter, trickling filter, and decanter, being also organized in series, with volumes of 300, 190, 250, and 150 L, respectively. Hydraulic retention times (HRT) applied in the first UASB reactors were 40, 30, 20, and 11 h in systems I and II. The average removal efficiencies of total and thermotolerant coliforms in system I were 92.92% to 99.50% and 94.29% to 99.56%, respectively, and increased in system II to 99.45% to 99.91% and 99.52% to 99.93%, respectively. Average removal rates of helminth eggs in system I were 96.44% to 99.11%, reaching 100% as in system II. In reactor sludge, the counts of total and thermotolerant coliforms ranged between 105 and 109 MPN (100 mL)−1, while helminth eggs ranged from 0.86 to 9.27 eggs g−1 TS. PMID:24812560

  3. Kinetic study of biogas production from energy crops and animal waste slurry: effect of organic loading rate and reactor size.

    PubMed

    Mähnert, P; Linke, B

    2009-01-01

    Biogas production in agriculture is processed mostly continuously at mesophilic temperatures in completely stirred tank reactors. Therefore, reactor performance data were studied in long-term semi-continuous laboratory-scale experiments with maize silage, whole-crop rye silage and fodder beet silage as mono-substrate and cattle slurry at mesophilic temperatures. For calculation of biogas yield as function of the organic loading rate, a hyperbolic equation was developed on the base of a first-order reaction rate for substrate degradation. The biogas yield depends also on the maximum biogas yield, the concentration of volatile solids of the input, the density of the effluent, the density of the biogas and the reaction rate constant, which are all substrate- or process-specific. Values of the theoretical maximum biogas yield and the reaction rate constant were observed in the range 0.61-0.93 m3 per kg volatile solids and 0.032-0.316 d(-1), respectively. By means of the hyperbolic equation, the proportion of the biogas yield from the maximum can be calculated for the first and a second reactor which also depends on the volume of each reactor. PMID:19213471

  4. The problems of mass transfer and formation of deposits of corrosion products on fuel assemblies of a VVER-1200 reactor

    NASA Astrophysics Data System (ADS)

    Rodionov, Yu. A.; Kritskii, V. G.; Berezina, I. G.; Gavrilov, A. V.

    2014-03-01

    On the basis of examination of materials published both in Russia and abroad, as well as their own investigations, the authors explain the reasons for the occurrence of such effects as AOA (Axial Offset Anomalies) and an increase in the coolant pressure difference in the core of nuclear reactors of the VVER type. To detect the occurrence of the AOA effect, the authors suggest using the specific activity of 58Co in the coolant. In the VVER-1200 design the thermohydraulic regime for fuel assemblies in the first year of their service life involves slight boiling of the coolant in the upper part of the core, which may induce the occurrence of the AOA effect, intensification of corrosion of fuel claddings, and abnormal increase in deposition of corrosion products. Radiolysis of the water coolant in the boiling section (boiling in pores of deposits) may intensify not only general corrosion but also a localized (nodular) one. As a result of intensification of the corrosion processes and growth of deposits, deterioration of the radiation situation in the rooms of the primary circuit of a VVER-1200 reactor as compared to that at nuclear power plants equipped with reactors of the VVER-1000 type is possible. Recommendations for preventing the AOA effect at nuclear power plants with VVER-1200 reactors on the matter of the direction of further investigations are made.

  5. Cellulase production by Trichoderma harzianum in static and mixed solid-state fermentation reactors under nonaseptic conditions

    SciTech Connect

    Deschamps, F.; Giuliano, C.; Asther, M.; Huet, M.C.; Roussos, S.

    1985-09-01

    Cellulase production from lignocellulosic materials was studied in solid-state cultivation by both static and mixed techniques under nonaseptic conditions. The effects of fermentation conditions, such as moisture content, pH, temperature, and aeration, on cellulase production by Trichoderma harzianum using a mixture of wheat straw (80%) and bran (20%) were investigated. With a moisture content of 74% and a pH of 5.8, 18 IU filter paper activity and 198 IU endoglucanase activity/g initial substrate content were obtained in 66 hours. The extension from static column cultivation to stirred tank reactor of 65 l capacity gave similar yields of cellulase.

  6. Heterotrophic denitrification plays an important role in N₂O production from nitritation reactors treating anaerobic sludge digestion liquor.

    PubMed

    Wang, Qilin; Jiang, Guangming; Ye, Liu; Pijuan, Maite; Yuan, Zhiguo

    2014-10-01

    Nitrous oxide (N2O) emissions from nitritation reactors receiving real anaerobic sludge digestion liquor have been reported to be substantially higher than those from reactors receiving synthetic digestion liquor. This study aims to identify the causes for the difference, and to develop strategies to reduce N2O emissions from reactors treating real digestion liquor. Two sequencing batch reactors (SBRs) performing nitritation, fed with real (SBR-R) and synthetic (SBR-S) digestion liquors, respectively, were employed. The N2O emission factors for SBR-R and SBR-S were determined to be 3.12% and 0.80% of the NH4(+)-N oxidized, respectively. Heterotrophic denitrification supported by the organic carbon present in the real digestion liquor was found to be the key contributor to the higher N2O emission from SBR-R. Heterotrophic nitrite reduction likely stopped at N2O (rather than N2), with a hypothesised cause being free nitrous acid inhibition. This implies that all nitrite reduced by heterotrophic bacteria was converted to and emitted as N2O. Increasing dissolved oxygen (DO) concentration from 0.5 to 1.0 mg/L, or above, decreased aerobic N2O production from 2.0% to 0.5% in SBR-R, whereas aerobic N2O production in SBR-S remained almost unchanged (at approximately 0.5%). We hypothesised that DO at 1 mg/L or above suppressed heterotrophic nitrite reduction thus reduced aerobic heterotrophic N2O production. We recommend that DO in a nitritation system receiving anaerobic sludge digestion liquor should be maintained at approximately 1 mg/L to minimise N2O emission. PMID:24956602

  7. Low enriched uranium foil plate target for the production of fission Molybdenum-99 in Pakistan Research Reactor-1

    NASA Astrophysics Data System (ADS)

    Mushtaq, A.; Iqbal, Masood; Bokhari, Ishtiaq Hussain; Mahmood, Tayyab

    2009-04-01

    Low enriched uranium foil (19.99% 235U) will be used as target material for the production of fission Molybdenum-99 in Pakistan Research Reactor-1 (PARR-1). LEU foil plate target proposed by University of Missouri Research Reactor (MURR) will be irradiated in PARR-1 for the production of 100Ci of Molybdenum-99 at the end of irradiation, which will be sufficient to prepare required 99Mo/ 99mTc generators at Pakistan Institute of Nuclear Science and Technology, Islamabad (PINSTECH) and its supply in the country. Neutronic and thermal hydraulic analysis for the fission Molybdenum-99 production at PARR-1 has been performed. Power levels in target foil plates and their corresponding irradiation time durations were initially determined by neutronic analysis to have the required neutron fluence. Finally, the thermal hydraulic analysis has been carried out for the proposed design of the target holder using LEU foil plates for fission Molybdenum-99 production at PARR-1. Data shows that LEU foil plate targets can be safely irradiated in PARR-1 for production of desired amount of fission Molybdenum-99.

  8. Preliminary risks associated with postulated tritium release from production reactor operation

    SciTech Connect

    O'Kula, K.R.; Horton, W.H.

    1988-01-01

    The Probabilistic Risk Assessment (PRA) of Savannah River Plant (SRP) reactor operation is assessing the off-site risk due to tritium releases during postulated full or partial loss of heavy water moderator accidents. Other sources of tritium in the reactor are less likely to contribute to off-site risk in non-fuel melting accident scenarios. Preliminary determination of the frequency of average partial moderator loss (including incidents with leaks as small as .5 kg) yields an estimate of /approximately/1 per reactor year. The full moderator loss frequency is conservatively chosen as 5 /times/ 10/sup /minus/3/ per reactor year. Conditional consequences, determined with a version of the MACCS code modified to handle tritium, are found to be insignificant. The 95th percentile individual cancer risk is 4 /times/ 10/sup /minus/8/ per reactor year within 16 km of the release point. The full moderator loss accident contributes about 75% of the evaluated risks. 13 refs., 4 figs., 5 tabs.

  9. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production

    SciTech Connect

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Weaver, Kevan Dean

    2002-01-01

    The use of supercritical temperature and pressure light water as the coolant in a direct-cycle nuclear reactor offers potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to 46%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type recirculation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If a tight fuel rod lattice is adopted, it is possible to significantly reduce the neutron moderation and attain fast neutron energy spectrum conditions. In this project a supercritical water reactor concept with a simple, blanket-free, pancake-shaped core will be developed. This type of core can make use of either fertile or fertile-free fuel and retain the hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity.

  10. Measurements of actinide-fission product yields in Caliban and Prospero metallic core reactor fission neutron fields

    SciTech Connect

    Casoli, P.; Authier, N.; Laurec, J.; Bauge, E.; Granier, T.

    2011-07-01

    In the 1970's and early 1980's, an experimental program was performed on the facilities of the CEA Valduc Research Center to measure several actinide-fission product yields. Experiments were, in particular, completed on the Caliban and Prospero metallic core reactors to study fission-neutron-induced reactions on {sup 233}U, {sup 235}U, and {sup 239}Pu. Thick actinide samples were irradiated and the number of nuclei of each fission product was determined by gamma spectrometry. Fission chambers were irradiated simultaneously to measure the numbers of fissions in thin deposits of the same actinides. The masses of the thick samples and the thin deposits were determined by mass spectrometry and alpha spectrometry. The results of these experiments will be fully presented in this paper for the first time. A description of the Caliban and Prospero reactors, their characteristics and performances, and explanations about the experimental approach will also be given in the article. A recent work has been completed to analyze and reinterpret these measurements and particularly to evaluate the associated uncertainties. In this context, calculations have also been carried out with the Monte Carlo transport code Tripoli-4, using the published benchmarked Caliban description and a three-dimensional model of Prospero, to determine the average neutron energy causing fission. Simulation results will be discussed in this paper. Finally, new fission yield measurements will be proposed on Caliban and Prospero reactors to strengthen the results of the first experiments. (authors)

  11. Bioenergy production from diluted poultry manure and microbial consortium inside Anaerobic Sludge Bed Reactor at sub-mesophilic conditions.

    PubMed

    Jaxybayeva, Aigerim; Yangin-Gomec, Cigdem; Cetecioglu, Zeynep; Ozbayram, E Gozde; Yilmaz, Fatih; Ince, Orhan

    2014-01-01

    In this study, anaerobic treatability of diluted chicken manure (with an influent feed ratio of 1 kg of fresh chicken manure to 6 L of tap water) was investigated in a lab-scale anaerobic sludge bed (ASB) reactor inoculated with granular seed sludge. The ASB reactor was operated at ambient temperature (17-25°C) in order to avoid the need of external heating up to higher operating temperatures (e.g., up to 35°C for mesophilic digestion). Since heat requirement for raising the temperature of incoming feed for digestion is eliminated, energy recovery from anaerobic treatment of chicken manure could be realized with less operating costs. Average biogas production rates were calculated ca. 210 and 242 L per kg of organic matter removed from the ASB reactor at average hydraulic retention times (HRTs) of 13 and 8.6 days, respectively. Moreover, average chemical oxygen demand (COD) removal of ca. 89% was observed with suspended solids removal more than 97% from the effluent of the ASB reactor. Influent ammonia, on the other hand, did not indicate any free ammonia inhibition due to dilution of the raw manure while pH and alkalinity results showed stability during the study. Microbial quantification results indicated that as the number of bacterial community decreased, the amount of Archaea increased through the effective digestion volume of the ASB reactor. Moreover, the number of methanogens displayed an uptrend like archaeal community and a strong correlation (-0.645) was found between methanogenic community and volatile fatty acid (VFA) concentration especially acetate. PMID:25065830

  12. Syngas production by thermochemical conversion of CO2 and H2O mixtures using a high-temperature heat pipe based reactor

    NASA Astrophysics Data System (ADS)

    Pearlman, Howard; Chen, Chien-Hua

    2012-10-01

    The design of a new high-temperature, solar-based reactor for thermochemical production of syngas using water and carbon dioxide will be discussed. The reactor incorporates the use of high-temperature heat pipe(s) that efficiently transfer the heat from a solar collector to a porous metal oxide material. Special attention is given to the thermal characteristics of the reactor, which are key factors affecting the overall system efficiency and amount of fuel produced. The thermochemical cycle that is considered is that for ceria based material. Preliminary data acquired from an early stage reactor, operated at temperatures up to 1100oC, is presented and efforts are now underway to increase the operating temperature of the reactor to 1300oC to further increase the efficiency of the thermochemical fuel production process.

  13. Effects of manipulating cyclic duration and pH on fermentative hydrogen production in an anaerobic sequencing batch reactor.

    PubMed

    Won, Seung-Gun; Lau, Anthony K

    2015-01-01

    The effects of cyclic duration and pH on biological hydrogen production were investigated in an anaerobic sequencing batch reactor. Experiments were conducted using cyclic duration of (4, 8, and 12 h) in combination with pH (4, 5, and 6) in a 3 × 3 factorial design, while hydraulic retention time and organic loading rate were maintained at 24 h and 10.3 g COD L(-1).d(-1), respectively. At pH 4, the effect of cyclic duration on hydrogen production was found to be insignificant. However, in runs with pH 5 and 6, a shorter cyclic duration of 4 h led to lower hydrogen productivity. The operational condition (pH 6, cyclic duration 12 h) induced higher hydrogen production rate of 2.3 ± 0.6 L H2/L reactor.d, whereas higher hydrogen yield of 2.2 ± 0.4 mol H2/mol sucrose was achieved at pH 5 and the same 12 h cyclic duration. The differences in hydrogen production were not statistically significant between 8 h and 12 h cyclic duration. Higher hydrogen production rates were associated with biomass (mixed liquor volatile suspended solids) concentration ranging from 8-13 g L(-1), but further increase in biomass growth was not accompanied by increased hydrogen production. Furthermore, a food-to-microorganism ratio of 0.84 was found to result in higher hydrogen production rate. PMID:25901853

  14. Tokamak reactor for treating fertile material or waste nuclear by-products

    DOEpatents

    Kotschenreuther, Michael T.; Mahajan, Swadesh M.; Valanju, Prashant M.

    2012-10-02

    Disclosed is a tokamak reactor. The reactor includes a first toroidal chamber, current carrying conductors, at least one divertor plate within the first toroidal chamber and a second chamber adjacent to the first toroidal chamber surrounded by a section that insulates the reactor from neutrons. The current carrying conductors are configured to confine a core plasma within enclosed walls of the first toroidal chamber such that the core plasma has an elongation of 1.5 to 4 and produce within the first toroidal chamber at least one stagnation point at a perpendicular distance from an equatorial plane through the core plasma that is greater than the plasma minor radius. The at least one divertor plate and current carrying conductors are configured relative to one another such that the current carrying conductors expand the open magnetic field lines at the divertor plate.

  15. Enhanced production of artemisinin by hairy root cultivation of Artemisia annua in a modified stirred tank reactor.

    PubMed

    Patra, Nivedita; Srivastava, Ashok K

    2014-11-01

    Artemisinin is an important drug commonly used in the treatment of malaria as a combination therapy. It is primarily produced by a plant Artemisia annua, however, its supply from plant is significantly lower than its huge demand and therefore alternative in vitro production routes are sought. Hairy root cultivation could be one such alternative production protocol. Agrobacterium rhizogenes was used to induce hairy roots of A. annua. Statistical optimization of media was thereafter attempted to maximize the biomass/artemisinin production. The growth and product formation kinetics and the significant role of O2 in hairy root propagation were established in optimized media. Mass cultivation of hairy roots was, thereafter, attempted in a modified 3-L Stirred Tank Bioreactor (Applikon Dependable Instruments, The Netherlands) using optimized culture conditions. The reactor was suitably modified to obtain profuse growth of hairy roots by segregating and protecting the growing roots from the agitator rotation in the reactor using a perforated Teflon disk. It was possible to produce 18 g biomass L(-1) (on dry weight basis) and 4.63 mg L(-1) of artemisinin in 28 days, which increased to 10.33 mg L(-1) by the addition of elicitor methyl jasmonate. PMID:25172060

  16. Production of ethanol from starch by co-immobilized Zymomonas mobilis -- Glucoamylase in a fluidized-bed reactor

    SciTech Connect

    Sun, M.Y.; Davison, B.H.; Bienkowski, P.R. |; Nghiem, N.P.; Webb, O.

    1997-08-01

    The production of ethanol from starch was studied in a fluidized-bed reactor (FBR) using co-immobilized Zymomonas mobilis and glucoamylase. The FBR was a glass column of 2.54 cm in diameter and 120 cm in length. The Z. mobilis and glucoamylase were co-immobilized within small uniform beads (1.2 to 2.5 mm diameter) of {kappa}-carrageenan. The substrate for ethanol production was a soluble starch. Light steep water was used as the complex nutrient source. The experiments were performed at 35 C and pH range 4.0 to 5.5. The substrate concentrations ranged from 40 to 185 g/L and the feed rates from 10 to 37 mL/min. Under relaxed sterility conditions, the FBR was successfully operated for a period of 22 days, during which no contamination or structural failure of the biocatalyst beads was observed. Maximum volumetric productivity of 38 g ethanol/L-h, which was 76% of the theoretical value, was obtained. Typical ethanol volumetric productivity was in the range of 15 to 20 g/L-h. The average yield was 0.51 g ethanol/g substrate consumed, which was 90% of the theoretical yield. Very low levels of glucose were observed in the reactor, indicating that starch hydrolysis was the rate-limiting step.

  17. Continuous biodiesel production in a fixed bed reactor packed with anion-exchange resin as heterogeneous catalyst.

    PubMed

    Ren, Yanbiao; He, Benqiao; Yan, Feng; Wang, Hong; Cheng, Yu; Lin, Ligang; Feng, Yaohui; Li, Jianxin

    2012-06-01

    A continuous biodiesel production from the transesterification of soybean oil with methanol was investigated in a fixed bed reactor packed with D261 anion-exchange resin as a heterogeneous catalyst. The conversion to biodiesel achieved 95.2% within a residence time 56 min under the conditions: reaction temperature of 323.15K, n-hexane/soybean oil weight rate of 0.5, methanol/soybean oil molar ratio of 9:1 and feed flow rate of 1.2 ml/min. The resin can be regenerated in-situ and restored to the original activity to achieve continuous production after the resin deactivation. The product obtained was mainly composed of methyl esters. No glycerol in the product was detected due to the resin adsorbing glycerol in the fixed bed, which solved the issue of glycerol separation from biodiesel. It is believed that the fixed bed reactor with D261 has a potential commercial application in the transesterification of triglyceride. PMID:22138595

  18. Continuous hydrogen production from co-digestion of municipal food waste and kitchen wastewater in mesophilic anaerobic baffled reactor.

    PubMed

    Tawfik, A; El-Qelish, M

    2012-06-01

    This study was carried out to assess the impact of organic loading rate (OLR) on the performance of mesophilic anaerobic baffled reactor (ABR) for H(2) production from a co-digestion of municipal food waste and kitchen wastewater. The reactor was operated at different organic loading rates (OLRs) of 29, 36 and 47 g COD(total)/Ld. The hydraulic retention time (HRT) was kept constant at 1.6d. The results showed that increasing the OLR from 29 to 36 g COD(total)/Ld, leads to a significant (p □ 0.01) drop in the H(2) production from 6.0±0.5 to 5.4±1.04 L H(2)/d, respectively. However, the H(2) production remained at the same level of 5.3±1.04 L H(2)/d at increasing the OLR from 36 to 47 g COD(total)/Ld. The H(2) generation was mainly due to conversion of COD (57%) and carbohydrate (81%). Protein and lipids conversion represents only 23.3% and 4.1% respectively for H(2) production. PMID:22446053

  19. Novel Magnetically Fluidized Bed Reactor Development for the Looping Process: Coal to Hydrogen Production R&D

    SciTech Connect

    Mei, Renwei; Hahn, David; Klausner, James; Petrasch, Jorg; Mehdizadeh, Ayyoub; Allen, Kyle; Rahmatian, Nima; Stehle, Richard; Bobek, Mike; Al-Raqom, Fotouh; Greek, Ben; Li, Like; Chen, Chen; Singh, Abhishek; Takagi, Midori; Barde, Amey; Nili, Saman

    2013-09-30

    The coal to hydrogen project utilizes the iron/iron oxide looping process to produce high purity hydrogen. The input energy for the process is provided by syngas coming from gasification process of coal. The reaction pathways for this process have been studied and favorable conditions for energy efficient operation have been identified. The Magnetically Stabilized Porous Structure (MSPS) is invented. It is fabricated from iron and silica particles and its repeatable high performance has been demonstrated through many experiments under various conditions in thermogravimetric analyzer, a lab-scale reactor, and a large scale reactor. The chemical reaction kinetics for both oxidation and reduction steps has been investigated thoroughly inside MSPS as well as on the surface of very smooth iron rod. Hydrogen, CO, and syngas have been tested individually as the reducing agent in reduction step and their performance is compared. Syngas is found to be the most pragmatic reducing agent for the two-step water splitting process. The transport properties of MSPS including porosity, permeability, and effective thermal conductivity are determined based on high resolution 3D CT x-ray images obtained at Argonne National Laboratory and pore-level simulations using a lattice Boltzmann Equation (LBE)-based mesoscopic model developed during this investigation. The results of those measurements and simulations provide necessary inputs to the development of a reliable volume-averaging-based continuum model that is used to simulate the dynamics of the redox process in MSPS. Extensive efforts have been devoted to simulate the redox process in MSPS by developing a continuum model consist of various modules for conductive and radiative heat transfer, fluid flow, species transport, and reaction kinetics. Both the Lagrangian and Eulerian approaches for species transport of chemically reacting flow in porous media have been investigated and verified numerically. Both approaches lead to correct prediction of hydrogen production rates over a large range of experimental conditions in the laboratory scale reactor and the bench-scale reactor. In the economic analysis, a comparison of the hydrogen production plants using iron/iron oxide looping cycle and the conventional process has been presented. Plant configurations are developed for the iron/iron oxide looping cycle. The study suggests a higher electric power generation but a lower hydrogen production efficiency comparing with the conventional process. Additionally, it was shown that the price of H{sub 2} obtained from our reactor can be as low as $1.7/kg, which is 22% lower than the current price of the H{sub 2} obtained from reforming plants.

  20. Residence Time Distribution Measurement and Analysis of Pilot-Scale Pretreatment Reactors for Biofuels Production: Preprint

    SciTech Connect

    Sievers, D.; Kuhn, E.; Tucker, M.; Stickel, J.; Wolfrum, E.

    2013-06-01

    Measurement and analysis of residence time distribution (RTD) data is the focus of this study where data collection methods were developed specifically for the pretreatment reactor environment. Augmented physical sampling and automated online detection methods were developed and applied. Both the measurement techniques themselves and the produced RTD data are presented and discussed.

  1. HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS

    SciTech Connect

    Gorensek, M.

    2011-07-06

    Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

  2. The application of an innovative continuous multiple tube reactor as a strategy to control the specific organic loading rate for biohydrogen production by dark fermentation.

    PubMed

    Gomes, Simone D; Fuess, Lucas T; Penteado, Eduardo D; Lucas, Shaiane D M; Gotardo, Jackeline T; Zaiat, Marcelo

    2015-12-01

    Biohydrogen production in fixed-bed reactors often leads to unstable and decreasing patterns because the excessive accumulation of biomass in the bed negatively affects the specific organic loading rate (SOLR) applied to the reactor. In this context, an innovative reactor configuration, i.e., the continuous multiple tube reactor (CMTR), was assessed in an attempt to better control the SOLR for biohydrogen production. The CMTR provides a continuous discharge of biomass, preventing the accumulation of solids in the long-term. Sucrose was used as the carbon source and mesophilic temperature conditions (25°C) were applied in three continuous assays. The reactor showed better performance when support material was placed in the outlet chamber to enhance biomass retention within the reactor. Although the SOLR could not be effectively controlled, reaching values usually higher than 10gsucroseg(-1)VSSd(-1), the volumetric hydrogen production and molar hydrogen production rates peaked, respectively, at 1470mLH2L(-1)d(-1) and 45mmolH2d(-1), indicating that the CMTR was a suitable configuration for biohydrogen production. PMID:26340028

  3. Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor.

    PubMed

    Vaxelaire, S; Gonze, E; Merlin, G; Gonthier, Y

    2008-12-01

    Conventional activated sludge wastewater treatment plants currently produce a large quantity of excess sludge. To reduce this sludge production and to improve sludge characteristics in view of their subsequent elimination, an ultrasonic cell disintegration process was studied. In a lab-scale continuous flow pilot plant, part of the return sludge was sonicated by low-frequency and high-powered ultrasound and then recycled to the aeration tank. Two parallel lines were used: one as a control and the other as an assay with ultrasonic treatment. The reactors were continuously fed with synthetic domestic wastewater with a COD (chemical oxygen demand) of approximately 0.5 g l(-) corresponding to a daily load of 0.35-0.50 kg COD kg(-1) TS d(-1). Removal efficiencies (carbon, particles), excess sludge production and sludge characteristics (particle size distribution, mineralization, respiration rate, biological component) were measured every day during the 56-day experiment. This study showed that whilst organic removal efficiency did not deteriorate, excess sludge production was decreased by about 25-30% by an ultrasonic treatment. Several hypotheses are advanced: (i) the treatment made a part of the organic matter soluble as a consequence of the floc disintegration, and optimised the conversion of the carbonaceous pollutants into carbon dioxide and (ii) the treatment modified the physical characteristics of sludge by a mechanical effect: floc size was reduced, increasing the exchange surface and sludge activity. The originality of this study is that experiments were conducted in a continuous-flow activated sludge reactor rather than in a batch reactor. PMID:19149352

  4. Analysis of Reference Design for Nuclear-Assisted Hydrogen Production at 750°C Reactor Outlet Temperature

    SciTech Connect

    Michael G. McKellar; Edwin A. Harvego

    2010-05-01

    The use of High Temperature Electrolysis (HTE) for the efficient production of hydrogen without the greenhouse gas emissions associated with conventional fossil-fuel hydrogen production techniques has been under investigation at the Idaho National Engineering Laboratory (INL) for the last several years. The activities at the INL have included the development, testing and analysis of large numbers of solid oxide electrolysis cells, and the analyses of potential plant designs for large scale production of hydrogen using a high-temperature gas-cooled reactor (HTGR) to provide the process heat and electricity to drive the electrolysis process. The results of this research led to the selection in 2009 of HTE as the preferred concept in the U.S. Department of Energy (DOE) hydrogen technology down-selection process. However, the down-selection process, along with continued technical assessments at the INL, has resulted in a number of proposed modifications and refinements to improve the original INL reference HTE design. These modifications include changes in plant configuration, operating conditions and individual component designs. This report describes the resulting new INL reference design coupled to two alternative HTGR power conversion systems, a Steam Rankine Cycle and a Combined Cycle (a Helium Brayton Cycle with a Steam Rankine Bottoming Cycle). Results of system analyses performed to optimize the design and to determine required plant performance and operating conditions when coupled to the two different power cycles are also presented. A 600 MWt high temperature gas reactor coupled with a Rankine steam power cycle at a thermal efficiency of 44.4% can produce 1.85 kg/s of hydrogen and 14.6 kg/s of oxygen. The same capacity reactor coupled with a combined cycle at a thermal efficiency of 42.5% can produce 1.78 kg/s of hydrogen and 14.0 kg/s of oxygen.

  5. Enrichment of specific electro-active microorganisms and enhancement of methane production by adding granular activated carbon in anaerobic reactors.

    PubMed

    Lee, Jung-Yeol; Lee, Sang-Hoon; Park, Hee-Deung

    2016-04-01

    Direct interspecies electron transfer (DIET) via conductive materials can provide significant benefits to anaerobic methane formation in terms of production amount and rate. Although granular activated carbon (GAC) demonstrated its applicability in facilitating DIET in methanogenesis, DIET in continuous flow anaerobic reactors has not been verified. Here, evidences of DIET via GAC were explored. The reactor supplemented with GAC showed 1.8-fold higher methane production rate than that without GAC (35.7 versus 20.1±7.1mL-CH4/d). Around 34% of methane formation was attributed to the biomass attached to GAC. Pyrosequencing of 16S rRNA gene demonstrated the enrichment of exoelectrogens (e.g. Geobacter) and hydrogenotrophic methanogens (e.g. Methanospirillum and Methanolinea) from the biomass attached to GAC. Furthermore, anodic and cathodic currents generation was observed in an electrochemical cell containing GAC biomass. Taken together, GAC supplementation created an environment for enriching the microorganisms involved in DIET, which increased the methane production rate. PMID:26836607

  6. Evaluation of selected ex-reactor accidents related to the tritium and medical isotope production mission at the FFTF

    SciTech Connect

    Himes, D.A.

    1997-11-17

    The Fast Flux Test Facility (FFTF) has been proposed as a production facility for tritium and medical isotopes. A range of postulated accidents related to ex-reactor irradiated fuel and target handling were identified and evaluated using new source terms for the higher fuel enrichment and for the tritium and medical isotope targets. In addition, two in-containment sodium spill accidents were re-evaluated to estimate effects of increased fuel enrichment and the presence of the Rapid Retrieval System. Radiological and toxicological consequences of the analyzed accidents were found to be well within applicable risk guidelines.

  7. Wastewater treatment from biodiesel production via a coupled photo-Fenton-aerobic sequential batch reactor (SBR) system.

    PubMed

    Ramírez, Ximena María Vargas; Mejía, Gina Maria Hincapié; López, Kelly Viviana Patiño; Vásquez, Gloria Restrepo; Sepúlveda, Juan Miguel Marín

    2012-01-01

    A coupled system of the photo-Fenton advanced oxidation technique and an aerobic sequential batch reactor (SBR) was used to treat wastewater from biodiesel production using either palm or castor oil. The photo-Fenton reaction and biological process were evaluated individually and were effective at treating the wastewater; nevertheless, each process required longer degradation times for the wastewater pollutants compared with the coupled system. The proposed coupled photo-Fenton/aerobic SBR system obtained a 90% reduction of the chemical oxygen demand (COD) in half of the time required for the biological system individually. PMID:22766873

  8. Nitrite production in a partial denitrifying upflow sludge bed (USB) reactor equipped with gas automatic circulation (GAC).

    PubMed

    Cao, Shenbin; Li, Baikun; Du, Rui; Ren, Nanqi; Peng, Yongzhen

    2016-03-01

    Nitrite production in a partial denitrifying (NO3(-)-N→NO2(-)-N) upflow sludge bed (USB) reactor equipped with gas automatic circulation (GAC) was investigated at ambient temperature (28.8-14.1 °C). The nitrite production rate (NPR) increased with the nitrate loading rate (NLR). Average NPR of 6.63 kgN m(-3) d(-1) was obtained at 28.0 °C with the organic loading rate (OLR) and NLR of 25.38 KgCOD∙m(-3)∙d(-1) and 10.82 kgN m(-3) d(-1), respectively. However, serious sludge floatation was observed when the NLR increased to 13.18 kgN m(-3) d(-1), which might be attributed to sludge bulking at high NLR. The USB reactor recovered rapidly when seeded with the sludge discharged before the deteriorated period, and a stable NPR of ∼4.35 kgN m(-3) d(-1) was achieved at 14.1-15.7 °C in the following 100-day operation, during which the maximum nitrate-to-nitrite transformation ratio (NTR) of 81.4% was achieved at the GAC rate of 1.08 L h(-1). The application of GAC in the partial denitrifying USB reactor enhanced mass transfer, which effectively avoided the channel and dead space, and improved the nitrate transform to nitrite. Moreover, it was found that the GAC system played an important role in promoting the stability of the USB reactor by preventing the sludge floatation. The Illumina high-throughput sequencing analysis revealed that the genus of Thauera was dominate in the USB reactor (67.2-50.2%), which may be responsible for the high nitrite accumulation. Results in this study have an important application in treating nitrate wastewater with an economic and efficient way by combining with ANAMMOX process. PMID:26760483

  9. ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

    SciTech Connect

    Gorensek, M.; Edwards, T.

    2009-06-11

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  10. Update to the NARAC NNPP Non-Reactor Source Term Products

    SciTech Connect

    Vogt, P

    2009-06-29

    Recent updates to NARAC plots for NNPP requires a modification to your iClient database. The steps you need to take are described below. Implementation of the non-reactor source terms in February 2009 included four plots, the traditional three instantaneous plots (1-3) and a new Gamma Dose Rate: 1. Particulate Air Concentration 2. Total Ground Deposition 3. Whole Body Inhalation Dose Rate (CEDE Rate) 4. Gamma Dose Rate These plots were all initially implemented to be instantaneous output and generated 30 minutes after the release time. Recently, Bettis and NAVSEA have requested the Whole Body CEDE rate plot to be changed to an integrated dose valid at two hours. This is consistent with the change made to the Thyroid Dose rate plot conversion to a 2-hour Integrated Thyroid dose for the Reactor and Criticality accidents.

  11. Computational and experimental prediction of dust production in pebble bed reactors, Part II

    SciTech Connect

    Mie Hiruta; Gannon Johnson; Maziar Rostamian; Gabriel P. Potirniche; Abderrafi M. Ougouag; Massimo Bertino; Louis Franzel; Akira Tokuhiro

    2013-10-01

    This paper is the continuation of Part I, which describes the high temperature and high pressure helium environment wear tests of graphite–graphite in frictional contact. In the present work, it has been attempted to simulate a Pebble Bed Reactor core environment as compared to Part I. The experimental apparatus, which is a custom-designed tribometer, is capable of performing wear tests at PBR relevant higher temperatures and pressures under a helium environment. This environment facilitates prediction of wear mass loss of graphite as dust particulates from the pebble bed. The experimental results of high temperature helium environment are used to anticipate the amount of wear mass produced in a pebble bed nuclear reactor.

  12. Fuel assembly for the production of tritium in light water reactors

    DOEpatents

    Cawley, William E.; Trapp, Turner J.

    1985-01-01

    A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

  13. Fuel assembly for the production of tritium in light water reactors

    DOEpatents

    Cawley, W.E.; Trapp, T.J.

    1983-06-10

    A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

  14. Fluidized Bed Membrane Reactors for Ultra Pure H₂ Production-A Step forward towards Commercialization.

    PubMed

    Helmi, Arash; Fernandez, Ekain; Melendez, Jon; Pacheco Tanaka, David Alfredo; Gallucci, Fausto; van Sint Annaland, Martin

    2016-01-01

    In this research the performance of a fluidized bed membrane reactor for high temperature water gas shift and its long term stability was investigated to provide a proof-of-concept of the new system at lab scale. A demonstration unit with a capacity of 1 Nm³/h of ultra-pure H₂ was designed, built and operated over 900 h of continuous work. Firstly, the performance of the membranes were investigated at different inlet gas compositions and at different temperatures and H₂ partial pressure differences. The membranes showed very high H₂ fluxes (3.89 × 10(-6) mol·m(-2)·Pa(-1)·s(-1) at 400 °C and 1 atm pressure difference) with a H₂/N₂ ideal perm-selectivity (up to 21,000 when integrating five membranes in the module) beyond the DOE 2015 targets. Monitoring the performance of the membranes and the reactor confirmed a very stable performance of the unit for continuous high temperature water gas shift under bubbling fluidization conditions. Several experiments were carried out at different temperatures, pressures and various inlet compositions to determine the optimum operating window for the reactor. The obtained results showed high hydrogen recovery factors, and very low CO concentrations at the permeate side (in average <10 ppm), so that the produced hydrogen can be directly fed to a low temperature PEM fuel cell. PMID:27007361

  15. Overview of Chromium Remediation Technology Evaluations At The Hanford Site, Richland Washington

    NASA Astrophysics Data System (ADS)

    Morse, J. G.; Hanson, J. P.

    2009-12-01

    This paper will present an overview of the different technologies and the results to date for optimizing and improving the remediation of Cr+6 in the soil and groundwater at the Hanford Site. The Hanford Site, par of the U.S. Department of Energy's (DOE)nuclear weapons complex, encompasses approximately 586 square miles in southeast Washington State. The Columbia River flows through the site (Hanford Reach.) Reactors were located along the Hanford Reach as part of the production process. Sodium dichromate was used as a corrosion inhibitor in the cooling water for the reactors. As a result chromium (Cr+6) is present in the soil and groundwater. Since the mid 90's interim groundwater pump and treat systems have been in place to try and contain or mitigate the migration of contaminated groundwater into the Columbia River. The primary concern being the protection of aquatic spawning habitat for salmon and other species. In order to improve the effectiveness of the remedial actions a number of different technologies have been evaluated and/or deployed. These include, permeable reactive barriers, in-situ bio-stimulation, in-situ chemical reduction, zero-valent iron injection and evaluation of improved above ground treatment technologies. An overview of the technologies and results to date are presented.

  16. Evaluation of Machine Guarding course taught in Richland, Washington, September 1--3, 1992

    SciTech Connect

    Wright, T.S.

    1993-03-01

    This section summarizes trainee evaluations for the Safety Training Section course, Machine Guarding'' which was conducted September 1-3, 1992 in Richland, Washington. This was the fifth time the course has been taught. This report summarizes the quantitative course evaluations that trainees provided upon completion of the course. Sections 1.3 and 1.4 provide written comments and examination results. Also provided are instructors' suggestions for improvement. Ratings were generally high, especially for the section on Subpart 0 guarding, which was consistent with the trainees' comments. Most of the trainees wanted a more in-depth look at Machine Guarding regulations. Lockout/ragout information and more site tours were frequently requested. In addition, the trainees were not interested in the subsection on personal protective equipment and electrical regulations.

  17. Evaluation of Machine Guarding course taught in Richland, Washington, September 1--3, 1992

    SciTech Connect

    Wright, T.S.

    1993-03-01

    This section summarizes trainee evaluations for the Safety Training Section course, ``Machine Guarding`` which was conducted September 1-3, 1992 in Richland, Washington. This was the fifth time the course has been taught. This report summarizes the quantitative course evaluations that trainees provided upon completion of the course. Sections 1.3 and 1.4 provide written comments and examination results. Also provided are instructors` suggestions for improvement. Ratings were generally high, especially for the section on Subpart 0 guarding, which was consistent with the trainees` comments. Most of the trainees wanted a more in-depth look at Machine Guarding regulations. Lockout/ragout information and more site tours were frequently requested. In addition, the trainees were not interested in the subsection on personal protective equipment and electrical regulations.

  18. Environmental Monitoring Plan United States Department of Energy Richland Operations Office. Revision 2

    SciTech Connect

    1997-11-10

    This Environmental Monitoring Plan was prepared for the US Department of Energy`s (DOE`s) Richland Operations Office (RL) to implement the requirements of DOE Order 5400.1. According to the Order, each DOE site, facility, or activity that uses, generates, releases, or manages significant pollutants or hazardous materials shall prepare a written environmental monitoring plan covering two major activities: (1) effluent monitoring and (2) environmental surveillance. The plan is to contain information discussing the rationale and design criteria for the monitoring programs, sampling locations and schedules, quality assurance requirements, program implementation procedures, analytical procedures, and reporting requirements. The plan`s purpose is to assist DOE in the management of environmental activities at the Hanford Site and to help ensure that operations on the site are conducted in an environmentally safe and sound manner.

  19. Geologic map of the Richland 1:100,000 quadrangle, Washington

    SciTech Connect

    Reidel, S.P.; Fecht, K.R.

    1993-09-01

    This map of the Richland 1:100,000-scale quadrangle, Washington, shows the geology of one of fifteen complete or partial 1:100,000-scale quadrangles that cover the southeast quadrant of Washington. Geologic maps of these quadrangles have been compiled by geologists with the Washington Division of Geology and Earth Resources (DGER) and Washington State University and are the principal data sources for a 1:250,000-scale geologic map of the southeast quadrant of Washington, which is in preparation. Eleven of these quadrangles are being released as DGER open-file reports. The map of the Wenatchee quadrangle has been published by the US Geological Survey, and the Moses Lake, Ritzville quadrangles have already been released.

  20. Structural testing of corrugated asbestos-cement roof panels at the Hanford Facilities, Richland, Washington

    SciTech Connect

    Moustafa, S.E.; Rodehaver, S.M.; Frier, W.A.

    1993-10-01

    This report describes a roof testing program that was carried out at the 105KE/KW Spent Fuel Storage Basins and their surrounding facilities at the Hanford Site in Richland, Washington. The roof panels were constructed in the mid 1950`s of corrugated asbestos-cement (A/C), which showed common signs of aging. Based on the construction specifications, the panels capacity to meet current design standards was questioned. Both laboratory and in-situ load testing of the corrugated A/C panels was conducted. The objective of the complete test program was to determine the structural integrity of the existing A/C roof panels installed in the 105KE and 105KW facilities. The data from these tests indicated that the roofs are capable of resisting the design loads and are considered safe. A second phase test to address the roof resistance to personnel and roof removal/roofing system installation equipment was recommended and is underway.

  1. Assessment of low-flow water quality in Richland Creek, Illinois

    USGS Publications Warehouse

    Freeman, W.O.; Schmidt, A.R.

    1986-01-01

    To study the effects of urbanization on water quality, the relations of several stream processes to concentrations of dissolved oxygen and other constituents were evaluated during low-flow periods for a 30.1-mi reach of Richland Creek in southwestern Illinois. The study used both measured data and computer simulations. Reaeration rates and traveltimes were measured at various flow rates using a steady-state, gas-tracer technique. Sediment-oxygen demands were measured at several locations throughout the study reach. Stream discharge, stage, temperature, and chemical-constituent concentrations were measured during two 24-hr periods in July and August 1984. The data were then used to describe water quality and to calibrate and verify the QUAL-II one-dimensional, steady-state, water quality model. (USGS)

  2. An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

    SciTech Connect

    Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry; Wesley R. Deason; Michael G. McKellar

    2014-03-01

    Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feed a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.

  3. 300 Area process sewer piping upgrade and 300 Area treated effluent disposal facility discharge to the City of Richland Sewage System, Hanford Site, Richland, Washington

    SciTech Connect

    1995-05-01

    The U.S. Department of Energy (DOE) is proposing to upgrade the existing 300 Area Process Sewer System by constructing and operating a new process sewer collection system that would discharge to the 300 Area Treated Effluent Disposal Facility. The DOE is also considering the construction of a tie-line from the TEDF to the 300 Area Sanitary Sewer for discharging the process wastewater to the City of Richland Sewage System. The proposed action is needed because the integrity of the old piping in the existing 300 Area Process Sewer System is questionable and effluents might be entering the soil column from leaking pipes. In addition, the DOE has identified a need to reduce anticipated operating costs at the new TEDF. The 300 Area Process Sewer Piping Upgrade (Project L-070) is estimated to cost approximately $9.9 million. The proposed work would involve the construction and operation of a new process sewer collection system. The new system would discharge the effluents to a collection sump and lift station for the TEDF. The TEDF is designed to treat and discharge the process effluent to the Columbia River. The process waste liquid effluent is currently well below the DOE requirements for radiological secondary containment and is not considered a RCRA hazardous waste or a State of Washington Hazardous Waste Management Act dangerous waste. A National Pollutant Discharge Elimination, System (NPDES) permit has been obtained from the U.S. Environmental Protection Agency for discharge to the Columbia River. The proposed action would upgrade the existing 300 Area Process Sewer System by the construction and operation of a new combined gravity, vacuum, and pressurized process sewer collection system consisting of vacuum collection sumps, pressure pump stations, and buried polyvinyl chloride or similar pipe. Two buildings would also be built to house a main collection station and a satellite collection station.

  4. 76 FR 37888 - Yellowstone Valley Railroad, L.L.C.-Discontinuance of Service Exemption-in Dawson and Richland...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Surface Transportation Board Yellowstone Valley Railroad, L.L.C.--Discontinuance of Service Exemption--in Dawson and Richland Counties, Mont. Yellowstone Valley Railroad, L.L.C. (YVRR) \\1\\ has filed a verified... Yellowstone Valley Railroad, Inc. See Watco Holdings, Watco Companies, and Watco Transp....

  5. A Fisheries Evaluation of the Richland and Wapato Canal Fish Screening Facilities, Spring 1987 : Annual Report.

    SciTech Connect

    Neitzel, Duane A.; Abernethy, C.Scott; Lusty, E.William; Wampler, Sally J.

    1988-02-01

    We evaluated the effectiveness of new fish screening facilities at the Richland and Wapato canals in south-central Washington State. The screen integrity tests at the Richland Screens indicated that 100% of fall chinook salmon fry (Oncorhynchus tshawytscha) released in front of the screens were prevented from entering the canal behind the screens. Our estimate is based on a 61% catch efficiency for control fish planted behind the screens. At the Wapato Canal, we estimated that between 3% and 4% of the test fish were either impinged on the screen surface and passed over the screens or passed through faulty screen seals. Our estimate is based over the screens or passed through faulty screen seals. Our estimate is based on a greater than 90% capture of control fish released in front of the screens. At the Wapato Screens, we estimated that 0.8% of steelhead smolts (Salmo gairdneri) and 1.4% of spring chinook salmon smolts released during low canal flow tests wee descaled. During full canal flow tests, 1.6% of the steelhead and 3.1% of the spring chinook salmon released were descaled. The fish return pipe at the Wapato Canal was tested: the estimate of descaled test fish wa not different from the estimate of descaled control fish. The time required for fish to exit from the Wapato Screen forebay varied with species and with canal flow. During low canal flows, 43.2% of steelhead and 61.6% of spring chinook salmon smolts released at the trash racks were captured in the fish return within 96 hr. 11 refs., 11 figs., 10 tabs.

  6. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1958-04-22

    A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

  7. 27. The top of a typical pile, F Reactor in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. The top of a typical pile, F Reactor in February 1945 in this case, showing the vertical safety rods (VSRs) and the cables that support them. The rods could be dropped into the pile to effect a rapid shutdown. The four silvered-colored drums on the left contained boron solution and are part of the last ditch safety system. Should the VSRs channels become blocked by an occurrence such as an earthquake, the solution could be dumped into the VSR channels to help shut down the reactor. D-8334 - B Reactor, Richland, Benton County, WA

  8. CARBON COATED (CARBONOUS) CATALYST IN EBULLATED BED REACTOR FOR PRODUCTION OF OXYGENATED CHEMICALS FROM SYNGAS/CO2

    SciTech Connect

    Peizheng Zhou

    2001-10-26

    There are a number of exothermic chemical reactions which might benefit from the temperature control and freedom from catalyst fouling provided by the ebullated bed reactor technology. A particularly promising area is production of oxygenated chemicals, such as alcohols and ethers, from synthesis gas, which can be economically produced from coal or biomass. The ebullated bed operation requires that the small-diameter ({approx}1/32 inch) catalyst particles have enough mechanical strength to avoid loss by attrition. However, all of the State Of The Art (SOTA) catalysts and advanced catalysts for the purpose are low in mechanical strength. The patented carbon-coated catalyst technology developed in our laboratory converts catalyst particles with low mechanical strength to strong catalysts suitable for ebullated bed application. This R&D program is concerned with the modification on the mechanical strength of the SOTA and advanced catalysts so that the ebullated bed technology can be utilized to produce valuable oxygenated chemicals from syngas/CO{sub 2} efficiently and economically. The objective of this R&D program is to study the technical and economic feasibility of selective production of high-value oxygenated chemicals from synthesis gas and CO{sub 2} mixed feed in an ebullated bed reactor using carbon-coated catalyst particles.

  9. The effect of organic loading rate on VFA/COD ratio for methane production from an EGSB reactor.

    PubMed

    Wei, Bo; Yuan, Linjiang; Liu, Wenhui

    2015-07-01

    The present study evaluated the effect of organic loading rate (OLR) on VFA/COD ratio for continuous production of methane using an expanded granular sludge bed(EGSB) reactor for 200 d. Reactor performances were studied in treating high OLRs ranging from 4.91 +/- 0.54 to 16.79 +/- 1.62 g-COD l(-1)d(-1) of glucose-based synthetic wastewater in a mesophilic condition. Results showed that performance of anaerobic fermentation system was distinctly influenced by OLR in terms of organic removal efficiency, VFA yield, methane production rate and system stability.Acetic and propionic acids accounted for 80-90% of total VFA, and presented highest VFA concentration and composition of VFA showed minor changes with OLR variation. Moreover, an increase in OLR increased VFA/COD ratio in the whole operation period and high VFA/COD ratio could inhibit methanogenesis at high OLR (16.79 +/- 1.62 g-COD l(-1) d(-1)). PMID:26364485

  10. CARBON COATED (CARBONOUS) CATALYST IN EBULLATED BED REACTOR FOR PRODUCTION OF OXYGENATED CHEMICALS FROM SYNGAS/CO2

    SciTech Connect

    Peizheng Zhou

    2000-11-17

    There are a number of exothermic chemical reactions which might benefit from the temperature control and freedom from catalyst fouling provided by the ebullated bed reactor technology. A particularly promising area is production of oxygenated chemicals, such as alcohols and ethers, from synthesis gas, which can be economically produced from coal or biomass. The ebullated bed operation requires that the small-diameter ({approx} 1/32 inch) catalyst particles have enough mechanical strength to avoid loss by attrition. However, all of the State Of The Art (SOTA) catalysts and advanced catalysts for the purpose are low in mechanical strength. The patented carbon-coated catalyst technology developed in our laboratory converts catalyst particles with low mechanical strength to strong catalysts suitable for ebullated bed application. This R&D program is concerned with the modification on the mechanical strength of the SOTA and advanced catalysts so that the ebullated bed technology can be utilized to produce valuable oxygenated chemicals from syngas/CO{sub 2} efficiently and economically. The objective of this R&D program is to study the technical and economic feasibility of selective production of high-value oxygenated chemicals from synthesis gas and CO{sub 2} mixed feed in an ebullated bed reactor using carbon-coated catalyst particles.

  11. NEUTRONIC REACTOR

    DOEpatents

    Creutz, E.C.; Ohlinger, L.A.; Weinberg, A.M.; Wigner, E.P.; Young, G.J.

    1959-10-27

    BS>A reactor cooled by water, biphenyl, helium, or other fluid with provision made for replacing the fuel rods with the highest plutonium and fission product content without disassembling the entire core and for promptly cooling the rods after their replacement in order to prevent build-up of heat from fission product activity is described.

  12. Method for fabricating wrought components for high-temperature gas-cooled reactors and product

    DOEpatents

    Thompson, Larry D. (San Diego, CA); Johnson, Jr., William R. (San Diego, CA)

    1985-01-01

    A method and alloys for fabricating wrought components of a high-temperature gas-cooled reactor are disclosed. These wrought, nickel-based alloys, which exhibit strength and excellent resistance to carburization at elevated temperatures, include aluminum and titanium in amounts and ratios to promote the growth of carburization resistant films while preserving the wrought character of the alloys. These alloys also include substantial amounts of molybdenum and/or tungsten as solid-solution strengtheners. Chromium may be included in concentrations less than 10% to assist in fabrication. Minor amounts of carbon and one or more carbide-forming metals also contribute to high-temperature strength.

  13. Life cycle assessment of hydrogen production from S-I thermochemical process coupled to a high temperature gas reactor

    SciTech Connect

    Giraldi, M. R.; Francois, J. L.; Castro-Uriegas, D.

    2012-07-01

    The purpose of this paper is to quantify the greenhouse gas (GHG) emissions associated to the hydrogen produced by the sulfur-iodine thermochemical process, coupled to a high temperature nuclear reactor, and to compare the results with other life cycle analysis (LCA) studies on hydrogen production technologies, both conventional and emerging. The LCA tool was used to quantify the impacts associated with climate change. The product system was defined by the following steps: (i) extraction and manufacturing of raw materials (upstream flows), (U) external energy supplied to the system, (iii) nuclear power plant, and (iv) hydrogen production plant. Particular attention was focused to those processes where there was limited information from literature about inventory data, as the TRISO fuel manufacture, and the production of iodine. The results show that the electric power, supplied to the hydrogen plant, is a sensitive parameter for GHG emissions. When the nuclear power plant supplied the electrical power, low GHG emissions were obtained. These results improve those reported by conventional hydrogen production methods, such as steam reforming. (authors)

  14. The influence of the buffering capacity on the production of organic acids and alcohols from wastewater in anaerobic reactor.

    PubMed

    Silva, A J; Pozzi, E; Foresti, E; Zaiat, M

    2015-02-01

    Some bacteria common in anaerobic digestion process can ferment a broad variety of organic compounds to organic acids, alcohols, and hydrogen, which can be used as biofuels. Researches are necessary to control the microbial interactions in favor of the alcohol production, as intermediary products of the anaerobic digestion of organic compounds. This paper reports on the effect of buffering capacity on the production of organic acids and alcohols from wastewater by a natural mixed bacterial culture. The hypothesis tested was that the increase of the buffering capacity by supplementation of sodium bicarbonate in the influent results in benefits for alcohol production by anaerobic fermentation of wastewater. When the influent was not supplemented with sodium bicarbonate, the chemical oxygen demand (COD)-ethanol and COD-methanol detected in the effluent corresponded to 22.5 and 12.7 % of the COD-sucrose consumed. Otherwise, when the reactor was fed with influent containing 0.5 g/L of sodium bicarbonate, the COD-ethanol and COD-methanol were effluents that corresponded to 39.2 and 29.6 % of the COD-sucrose consumed. Therefore, the alcohol production by supplementation of the influent with sodium bicarbonate was 33.6 % higher than the fermentation of the influent without sodium bicarbonate. PMID:25480346

  15. Continuous production of cyclodextrins in an ultrafiltration membrane reactor, catalyzed by cyclodextrin glycosyltransferase from Bacillus circulans DF 9R.

    PubMed

    Rodríguez Gastón, Jorgelina A; Costa, Hernán; Ferrarotti, Susana A

    2015-01-01

    Cyclodextrins (CDs) are cyclic oligosaccharides of wide industrial application, whose synthesis is catalyzed by Cyclodextrin glycosyltransferase (CGTase) from starch. Here, CDs were produced using CGTase from Bacillus circulans DF 9R in continuous process and an ultrafiltration membrane reactor. The batch process was conducted as a control. This method allowed increasing the yield from 40 to 55.6% and the productivity from 26.1 to 99.5 mg of CD per unit of enzyme. The method also allowed obtaining a high-purity product. The flow rate remained at 50% of its initial value after 24 h of process, improving the results described in the literature for starch hydrolysis processes. CGTase remained active throughout the process, which could be explained by the protective effect of the substrate and reaction products on CGTase stability. In addition, batch processes were developed using starches from different sources. We concluded that any of the starches studied could be used as substrate for CD production with similar yields and product specificity. PMID:25583301

  16. The Phase Behavior Effect on the Reaction Engineering of Transesterification Reactions and Reactor Design for Continuous Biodiesel Production

    NASA Astrophysics Data System (ADS)

    Csernica, Stephen N.

    The demand for renewable forms of energy has increased tremendously over the past two decades. Of all the different forms of renewable energy, biodiesel, a liquid fuel, has emerged as one of the more viable possibilities. This is in large part due to the fact that biodiesel can readily be used in modern day diesel engines with nearly no engine modifications. It is commonly blended with conventional petroleum-derived diesel but it can also be used neat. As a result of the continued growth of the industry, there has been a correspondingly large increase in the scientific and technical research conducted on the subject. Much of the research has been conducted on the feasibility of using different types of feedstocks, which generally vary with respect to geographic locale, as well as different types of catalysts. Much of the work of the present study was involved with the investigation of the binary liquid-liquid nature of the system and its effects on the reaction kinetics. Initially, the development of an analytical method for the analysis of the compounds present in transesterification reaction mixtures using high performance liquid chromatography (HPLC) was developed. The use of UV(205 nm) as well as refractive index detection (RID) were shown capable to detect the various different types of components associated with transesterification reactions. Reversed-phase chromatography with isocratic elution was primarily used. Using a unique experimental apparatus enabling the simultaneous analysis of both liquid phases throughout the reaction, an experimental method was developed for measuring the reaction rate under both mass transfer control and reaction control. The transesterification reaction rate under each controlling mechanism was subsequently evaluated and compared. It was determined that the reaction rate is directly proportional to the concentration of triglycerides in the methanol phase. Furthermore, the reaction rate accelerates rapidly as the system transitions from two phases to a single phase, or pseudo-single phase. The transition to a single phase or pseudo-single phase is a function of the methanol content. Regardless, the maximum observed reaction rate occurs at the point of the phase transition, when the concentration of triglycerides in the methanol phase is largest. The phase transition occurs due to the accumulation of the primary product, biodiesel methyl esters. Through various experiments, it was determined that the rate of the triglyceride mass transfer into the methanol phase, as well as the solubility of triglycerides in methanol, increases with increasing methyl ester concentration. Thus, there exists some critical methyl ester concentration which favors the formation of a single or pseudo-single phase system. The effect of the by-product glycerol on the reaction kinetics was also investigated. It was determined that at low methanol to triglyceride molar ratios, glycerol acts to inhibit the reaction rate and limit the overall triglyceride conversion. This occurs because glycerol accumulates in the methanol phase, i.e. the primary reaction volume. When glycerol is at relatively high concentrations within the methanol phase, triglycerides become excluded from the reaction volume. This greatly reduces the reaction rate and limits the overall conversion. As the concentration of methanol is increased, glycerol becomes diluted and the inhibitory effects become dampened. Assuming pseudo-homogeneous phase behavior, a simple kinetic model incorporating the inhibitory effects of glycerol was proposed based on batch reactor data. The kinetic model was primarily used to theoretically compare the performance of different types of continuous flow reactors for continuous biodiesel production. It was determined that the inhibitory effects of glycerol result in the requirement of very large reactor volumes when using continuous stirred tank reactors (CSTR). The reactor volume can be greatly reduced using tubular style plug flow reactors (PFR). Despite this fact, the use of CSTRs is more common than the use of PFRs. This is mostly due to the fact that the two initial reactant phases are relatively immiscible and significant agitation is generally supplied to initiate the reaction. Based on the theoretical results, however, the use of a packed-bed tubular flow reactor was investigated experimentally. A series of two tubular flow reactors was built in the laboratory. The first reactor was of the shell and tube variety and also functioned as a preheater. The second reactor was larger and contained a packed-bed. Two different flow configurations were invested, upflow-upflow and downflow-downflow. It was determined that the downflow-downflow configuration provided significantly better triglyceride conversions that the upflow-upflow configuration.

  17. Experimental simulation of personal dosimetry in production of medical radioisotopes by research reactor.

    PubMed

    Mossadegh, N; Karimian, A; Shahhosseini, E; Mohammadzadeh, A; Sheibani, Sh

    2011-09-01

    Due to their work conditions, research reactor personnel are exposed to ionising nuclear radiations. Because the absorbed dose values are different for different tissues due to variations in sensitivity, in this work personal dosimetry has been performed under normal working conditions at anatomical locations relevant to more sensitive tissues as well as for the whole body by employing a Rando phantom and thermoluminescent dosemeters (TLDs). Fifty-two TLDs-100H were positioned at high-risk organ locations such as the thyroid, eyes as well as the left breast, which was used to assess the whole-body dose in order to study the absorbed doses originating from selected locations in the vicinity of the reactor. The results have employed the tissue weighting factors based on International Commission on Radiological Protection ICRP 103 and ICRP 60 and the measured results were below the dose limits recommended by ICRP. The mean effective dose rates calculated from ICRP 103 were the following: whole body, 30.64-6.44 µSv h(-1); thyroid, 1.22-0.23 µSv h(-1); prostate, 0.085-0.045 µSv h(-1); gonads, 1.00-0.51 µSv h(-1); breast, 3.68-0.77 µSv h(-1); and eyes, 33.74-7.01 µSv h(-1). PMID:21862507

  18. Nitrous oxide production pathways in a partial nitritation-anammox reactor: Isotopic evidence for nitrous oxide production associated anaerobic ammonium oxidation?

    NASA Astrophysics Data System (ADS)

    Wunderlin, P.; Harris, E. J.; Joss, A.; Emmenegger, L.; Kipf, M.; Mohn, J.; Siegrist, H.

    2014-12-01

    Nitrous oxide (N2O) is a strong greenhouse gas and a major sink for stratospheric ozone. In biological wastewater treatment N2O can be produced via several pathways. This study investigates the dynamics of N2O emissions from a nitritation-anammox reactor, and links its interpretation to the nitrogen and oxygen isotopic signature of the emitted N2O. A 400-litre single-stage nitritation-anammox reactor was operated and continuously fed with digester liquid. The isotopic composition of N2O emissions was monitored online with quantum cascade laser absorption spectroscopy (QCLAS; Aerodyne Research, Inc.; Waechter et al., 2008). Dissolved ammonium and nitrate were monitored online (ISEmax, Endress + Hauser), while nitrite was measured with test strips (Nitrite-test 0-24mgN/l, Merck). Table 1. Summary of experiments conducted to understand N2O emissions Experimental conditions O2[mgO2/L] NO2-[mgN/L] NH4+[mgN/L] N2O/NH4+[%] Normal operation <0.1 <0.5 10 0.6 Normal operation, high NH4+ <0.1 <0.5 100 6.1 High aeration 0.5 to 1.5 up to 50 10 and 50 4.9 NO2- addition (oxic) <0.1 <0.5 to 4 10 5.8 NO2- addition (anoxic) 0 <0.5 to 4 10 3.2 NH2OH addition <0.1 <0.5 10 2.5 Results showed that under normal operating conditions, the N2O isotopic site preference (SP = d15Nα - d15Nβ) was much higher than expected - up to 41‰ - strongly suggesting an unknown N2O production pathway, which is hypothesized to be mediated by anammox activity (Figure 1). A less likely explanation is that the SP of N2O was increased by partial N2O reduction by heterotrophic denitrification. Various experiments were conducted to further investigate N2O formation pathways in the reactor. Our data reveal that N2O emissions increased when reactor operation was not ideal, for example when dissolved oxygen was too high (Table 1). SP measurements confirmed that these N2O peaks were due to enhanced nitrifier denitrification, generally related to nitrite build-up in the reactor (Figure 1; Table 1). Overall, process control via online N2O monitoring was confirmed to be an ideal method to detect imbalances in reactor operation and regulate aeration, to ensure optimal reactor conditions and minimise N2O emissions. ReferencesWaechter H. et al. (2008) Optics Express, 16: 9239-9244. Wunderlin, P et al. (2013) Environmental Science & Technology 47: 1339-1348.

  19. Biomethane production and microbial community response according to influent concentration of molasses wastewater in a UASB reactor.

    PubMed

    Yun, Jeonghee; Lee, Sang Don; Cho, Kyung-Suk

    2016-05-01

    This study aimed to investigate the interaction between methane production performance and active microbial community dynamics at different loading rates by increasing influent substrate concentration. The model system was an upflow anaerobic sludge blanket (UASB) reactor using molasses wastewater. The active microbial community was analyzed using a ribosomal RNA-based approach in order to reflect active members in the UASB system. The methane production rate (MPR) increased with an increase in organic loading rate (OLR) from 3.6 to 5.5 g COD·L(-1)·day(-1) and then it decreased with further OLR addition until 9.7 g COD·L(-1)·day(-1). The UASB reactor achieved a maximum methane production rate of 0.48 L·L(-1)·day(-1) with a chemical oxygen demand (COD) removal efficiency of 91.2 % at an influent molasses concentration of 16 g COD·L(-1) (OLR of 5.5 g COD·L(-1)·day(-1)). In the archaeal community, Methanosarcina was predominant irrespective of loading rate, and the relative abundance of Methanosaeta increased with loading rate. In the bacterial community, Firmicutes and Eubacteriaceae were relatively abundant in the loading conditions tested. The network analysis between operation parameters and microbial community indicated that MPR was positively associated with most methanogenic archaea, including the relatively abundant Methanosarcina and Methanosaeta, except Methanofollis. The most abundant Methanosarcina was negatively associated with Bifidobacterium and Methanosaeta, whereas Methanosaeta was positively associated with Bifidobacterium. PMID:26810080

  20. Evaluation of kojic acid production in a repeated-batch PCS biofilm reactor.

    PubMed

    Liu, Jui-Ming; Yu, Ting-Chu; Lin, Shin-Ping; Hsu, Ren-Jun; Hsu, Kai-Di; Cheng, Kuan-Chen

    2016-01-20

    In this study, kojic acid, a secondary metabolite as an industrially important compound, was produced by Aspergillus oryzae (A. oryzae), which was immobilized in plastic composite support (PCS) bioreactor. Nitrogen deficient medium was applied to increase the production of KA in PCS-immobilized bioreactor. The efficiency of immobilized culture for kojic acid (KA) production and the effect of morphology of A. oryzae on KA production were evaluated. After three cycles of cultivation, 83.47 g/L of KA was produced in PCS bioreactor in nitrogen deficient medium with productivity of 3.09 g/L/d, which is higher than free suspension culture in batch fermentation. The morphology of A. oryzae mycelium changed under nitrogen starvation. Feather-like mycelium was observed with increasing KA production. RNA expression (kojA and kojT) results indicated that the nitrogen deficient environment had strong influence on KA production on the transcriptional level. PCS immobilized fermentation system, which allowed a repeated-batch fermentation with higher production and productivity, is a potential tool in industrial production of KA. PMID:26657710

  1. Production of fusion protein SpA::EcoRI in batch culture in a 60-L airlift tower loop reactor.

    PubMed

    Brandes, L; Wu, X; Maschke, H E; Jürgens, H; Reinhardt, B; Schügerl, K

    1993-01-01

    Escherichia coli JM103 carrying the expression plasmid pMTC48, repressor plasmid pRK248, and protection plasmid pEcoR4 was grown in a 60-L working volume airlift tower loop reactor on M9 minimal medium. Production of fusion protein SpA::EcoRI was induced by a temperature shift from 30 to 38 (optimum), 40, or 42 degrees C. The following parameters were monitored: cell mass concentration (X), total cell counts (TCC), number of colony-forming units (CFU), concentrations of glucose, acetate, ethanol, pyruvate, lactate, succinate, amino acids, and ammonia, and soluble and total protein content, as well as product concentration (enzyme activity of the fusion protein), dissolved oxygen concentration, oxygen utilization rate (OUR), CO2 production rate (CPR), respiration quotient (RQ), and volumetric mass-transfer coefficients (kLa). Product formation by temperature shift was only observed if LB concentrate was added to the culture at the same time the aeration rate was increased to avoid oxygen-transfer limitation. No product accumulation was observed with glucose and ammonia supplementation. During gene expression, X and TCC increased, CFU decreased, acetate increased, and the primary metabolite (ethanol, pyruvate, lactate) concentrations as well as OUR and CPR passed a maximum while RQ changed only slightly. These facts indicate that, during gene expression, the metabolic activity of the cell passes a maximum, and after that it decreases. With increasing aeration rate, the volumetric productivity increased, but the specific productivity with respect to the cell concentration decreased. PMID:7763587

  2. Screening for potential fermentative hydrogen production from black water and kitchen waste in on-site UASB reactor at 20 degrees C.

    PubMed

    Luostarinen, S; Pakarinen, O; Rintala, J

    2008-06-01

    The potential of black water and a mixture of black water and kitchen waste as substrates for on-site dark fermentative hydrogen production was screened in upflow anaerobic sludge blanket reactors at 20 degrees C. Three different inocula were used with and without heat treatment. With glucose, the highest specific hydrogenogenic activity was 69 ml H2 g volatile solids(-1) d(-1) in batch assays and the highest hydrogen yield 0.44 mol H2 mol glucose(-1) in upflow anaerobic sludge bed reactor. The mixture of black water and kitchen waste degraded readily into volatile fatty acids in the reactors, thus showing potential for hydrogen production. In the conditions applied, however, the highest end product was propionate and no hydrogen was produced. Black water alone apparently contained too little readily soluble carbohydrates for hydrogen producing bacteria, and little VFA and no hydrogen was produced. PMID:18702295

  3. Effect of inoculation process on lycopene production by Blakeslea trispora in a stirred-tank reactor.

    PubMed

    Wang, Qiang; Feng, Ling-Ran; Luo, Wei; Li, Han-Guang; Zhou, Ya; Yu, Xiao-Bin

    2015-01-01

    Lycopene biosynthesis by Blakeslea trispora was greatly enhanced in a stirred-tank reactor when a nonsynchronous inoculation process, in which the (+) mating type was inoculated after the (-) mating type has been grown for a certain period of time, was applied. The lycopene concentration with nonsynchronous inoculation in a 24-h inoculation interval was 33 % higher than that with synchronous inoculation. The optimum inoculation ratio was 1:2 (+/-) at the 36 and 48 h inoculum age of mating types (+) and (-), respectively. Fermentation time for the individual strains and mated conditions showed that the (+) mating type grows faster than the (-) mating type. Morphological observation showed that the mycelium ratio of B. trispora (-) in mating culture with nonsynchronous inoculation was higher than that with synchronous inoculation. The results indicated that nonsynchronous inoculation process increased the dominance of B. trispora (-) in joint cultivation and hence stimulated lycopene biosynthesis. PMID:25342268

  4. Supported Pd-Au Membrane Reactor for Hydrogen Production: Membrane Preparation, Characterization and Testing.

    PubMed

    Iulianelli, Adolfo; Alavi, Marjan; Bagnato, Giuseppe; Liguori, Simona; Wilcox, Jennifer; Rahimpour, Mohammad Reza; Eslamlouyan, Reza; Anzelmo, Bryce; Basile, Angelo

    2016-01-01

    A supported Pd-Au (Au 7wt%) membrane was produced by electroless plating deposition. Permeation tests were performed with pure gas (H₂, H₂, N₂, CO₂, CH₄) for long time operation. After around 400 h under testing, the composite Pd-Au membrane achieved steady state condition, with an H₂/N₂ ideal selectivity of around 500 at 420 °C and 50 kPa as transmembrane pressure, remaining stable up to 1100 h under operation. Afterwards, the membrane was allocated in a membrane reactor module for methane steam reforming reaction tests. As a preliminary application, at 420 °C, 300 kPa of reaction pressure, space velocity of 4100 h(-1), 40% methane conversion and 35% hydrogen recovery were reached using a commercial Ni/Al₂O₃ catalyst. Unfortunately, a severe coke deposition affected irreversibly the composite membrane, determining the loss of the hydrogen permeation characteristics of the supported Pd-Au membrane. PMID:27171067

  5. Interfacing the tandem mirror reactor to the sulfur-iodine process for hydrogen production

    SciTech Connect

    Galloway, T.R.

    1980-06-02

    The blanket is linked to the H/sub 2/SO/sub 4/ vaporization units and SO/sub 3/ decomposition reactor with either sodium or helium. The engineering and safety problems associated with these choices are discussed. This H/sub 2/SO/sub 4/ step uses about 90% of the TMR heat and is best close-coupled to the nuclear island. The rest of the process we propose to be driven by steam and does not require close-coupling. The sodium loop coupling seems to be preferable at this time. We can operate with a blanket around 1200 K and the SO/sub 3/ decomposer around 1050 K. This configuration offers double-barrier protection between Li-Na and the SO/sub 3/ process gases. Heat pipes offer an attractive alternate to provide an additional barrier, added modularity for increased reliability, and tritium concentration and isolation operations with very little thermal penalty.

  6. Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study

    PubMed Central

    Chen, Hsiao-Ching; Ju, Hen-Yi; Wu, Tsung-Ta; Liu, Yung-Chuan; Lee, Chih-Chen; Chang, Cheng; Chung, Yi-Lin; Shieh, Chwen-Jen

    2011-01-01

    An optimal continuous production of biodiesel by methanolysis of soybean oil in a packed-bed reactor was developed using immobilized lipase (Novozym 435) as a catalyst in a tert-butanol solvent system. Response surface methodology (RSM) and Box-Behnken design were employed to evaluate the effects of reaction temperature, flow rate, and substrate molar ratio on the molar conversion of biodiesel. The results showed that flow rate and temperature have significant effects on the percentage of molar conversion. On the basis of ridge max analysis, the optimum conditions were as follows: flow rate 0.1 mL/min, temperature 52.1°C, and substrate molar ratio 1 : 4. The predicted and experimental values of molar conversion were 83.31 ± 2.07% and 82.81 ± .98%, respectively. Furthermore, the continuous process over 30 days showed no appreciable decrease in the molar conversion. The paper demonstrates the applicability of using immobilized lipase and a packed-bed reactor for continuous biodiesel synthesis. PMID:20936129

  7. Submersible microbial desalination cell for simultaneous ammonia recovery and electricity production from anaerobic reactors containing high levels of ammonia.

    PubMed

    Zhang, Yifeng; Angelidaki, Irini

    2015-02-01

    High ammonia concentration in anaerobic reactors can seriously inhibit the anaerobic digestion process. In this study, a submersible microbial desalination cell (SMDC) was developed as an innovative method to lower the ammonia level in a continuous stirred tank reactor (CSTR) by in situ ammonia recovery and electricity production. In batch experiment, the ammonia concentration in the CSTR decreased from 6 to 0.7 g-N/L during 30 days, resulting in an average recovery rate of 80 g-N/m(2)/d. Meanwhile, a maximum power density of 0.710.5 W/m(2) was generated at 2.85 A/m(2). Both current driven NH4(+) migration and free NH3 diffusion were identified as the mechanisms responsible for the ammonia transportation. With an increase in initial ammonia concentration and a decrease in external resistance, the SMDC performance was enhanced. In addition, the coexistence of other cations in CSTR or cathode had no negative effect on the ammonia transportation. PMID:25496943

  8. Utilization of high-strength wastewater for the production of biogas as a renewable energy source using hybrid upflow anaerobic sludge blanket (HUASB) reactor

    SciTech Connect

    Shivayogimath, C.B.; Ramanujam, T.K.

    1998-07-01

    Anaerobic digestion of distillery spentwash, a high-strength wastewater, was studied using a hybrid upflow anaerobic sludge blanket (HUASB) reactor for 240 days under ambient conditions. The HUASB reactor combined an open volume in the bottom two-thirds of the reactor for sludge blanket and polypropylene pall rings packing in the upper one-third of the reactor. The aim of the study was to achieve optimum biogas production and waste treatment. Using non-granular anaerobic sewage sludge as seed, the start-up of the HUASB reactor was successfully completed, with the production of active bacterial granules of 1--2 mm size, within 90 days. Examination of the bacterial granules under scanning electron microscope (SEM) revealed that Methanothrix like microorganisms were the dominant species besides Methanosarcina. An organic loading of 24 kg COD/m{sup 3}d at a low hydraulic retention time (HRT) of 6 hours was achieved with 82% reduction in COD. Biogas with high methane content (80%) was produced at these loadings. The specific biogas yield was 0.36 m{sup 3} CH{sub 4}/kg COD. Packing in the upper third of the reactor was very efficient as a gas-solid separator (GSS); and in addition it retained the biomass.

  9. A low energy continuous reactor separator for the production of ethanol from corn grits/starch and biomass streams. 2nd Quarterly report, August 1--October 15, 1994

    SciTech Connect

    Not Available

    1994-11-01

    This project is an attempt to develop and demonstrate an improved reactor for the production of ethanol from starch and ligno-cellulosic streams. Bio-Process Innovations holds a patent on this reactor technology, and is directing the project. A Continuous Stirred Reactor Separator (CSRS) is being built on a pilot plant scale for testing at a small Iowa ethanol plant (Permeate Refining) while bench scale tests on the reactor system are being performed at Purdue University. The CSRS unit combines several operations within the confines of the reactor vessel: (1) complex carbohydrates are reduced to simple sugars by enzymatic breakdown; (2) sugars are converted to ethanol by yeast or bacteria; and (3) the ethanol is separated by a stripping gas stream. The ethanol is removed from the stripping gas in an absorber, and then taken to an extractive distillation column. This unit should allow concentrated feeds to be converted to ethanol, and the use of bottoms recycle will be extensively tested to establish the limits of minimizing net bottoms water production leaving the plant. During the first quarter, a flocculant yeast was selected, a xylose fermenting yeast strain selected, and some experiments on no-cook starch conversion to ethanol completed. During the last (second) quarter, the authors have tested the effect of bottoms water recirculation on the reactor performance, the performance of the lab scale unit on molasses, and done some work on biomass conversion to ethanol.

  10. Use of disposable reactors to generate inoculum cultures for E. coli production fermentations.

    PubMed

    Mahajan, Ekta; Matthews, Timothy; Hamilton, Ryan; Laird, Michael W

    2010-01-01

    Disposable technology is being used more each year in the biotechnology industry. Disposable bioreactors allow one to avoid expenses associated with cleaning, assembly and operations, as well as equipment validation. The WAVE bioreactor is well established for Chinese Hamster Ovary (CHO) production, however, it has not yet been thoroughly tested for E. coli production because of the high oxygen demand and temperature maintenance requirements of that platform. The objective of this study is to establish a robust process to generate inoculum for E. coli production fermentations in a WAVE bioreactor. We opted not to evaluate the WAVE system for production cultures because of the high cell densities required in our current E. coli production processes. Instead, the WAVE bioreactor 20/50 system was evaluated at laboratory scale (10-L) to generate inoculum with target optical densities (OD(550)) of 15 within 7-9 h (pre-established target for stainless steel fermentors). The maximum settings for rock rate (40 rpm) and angle (10.5) were used to maximize mass transfer. The gas feed was also supplemented with additional oxygen to meet the high respiratory demand of the culture. The results showed that the growth profiles for the inoculum cultures were similar to those obtained from conventional stainless steel fermentors. These inoculum cultures were subsequently inoculated into 10-L working volume stainless steel fermentors to evaluate the inocula performance of two different production systems during recombinant protein production. The results of these production cultures using WAVE inocula showed that the growth and recombinant protein production was comparable to the control data set. Furthermore, an economic analysis showed that the WAVE system would require less capital investment for installation and operating expenses would be less than traditional stainless steel systems. PMID:20730774

  11. Biofuels from Pyrolysis: Catalytic Biocrude Production in a Novel, Short-Contact Time Reactor

    SciTech Connect

    2010-01-01

    Broad Funding Opportunity Announcement Project: RTI is developing a new pyrolysis process to convert second-generation biomass into biofuels in one simple step. Pyrolysis is the decomposition of substances by heating—the same process used to render wood into charcoal, caramelize sugar, and dry roast coffee and beans. RTI’s catalytic biomass pyrolysis differs from conventional flash pyrolysis in that its end product contains less oxygen, metals, and nitrogen—all of which contribute to corrosion, instability, and inefficiency in the fuel-production process. This technology is expected to easily integrate into the existing domestic petroleum refining infrastructure, making it an economically attractive option for biofuels production.

  12. Transesterification of rapeseed oil for biodiesel production in trickle-bed reactors packed with heterogeneous Ca/Al composite oxide-based alkaline catalyst.

    PubMed

    Meng, Yong-Lu; Tian, Song-Jiang; Li, Shu-Fen; Wang, Bo-Yang; Zhang, Min-Hua

    2013-05-01

    A conventional trickle bed reactor and its modified type both packed with Ca/Al composite oxide-based alkaline catalysts were studied for biodiesel production by transesterification of rapeseed oil and methanol. The effects of the methanol usage and oil flow rate on the FAME yield were investigated under the normal pressure and methanol boiling state. The oil flow rate had a significant effect on the FAME yield for the both reactors. The modified trickle bed reactor kept over 94.5% FAME yield under 0.6 mL/min oil flow rate and 91 mL catalyst bed volume, showing a much higher conversion and operational stability than the conventional type. With the modified trickle bed reactor, both transesterification and methanol separation could be performed simultaneously, and glycerin and methyl esters were separated additionally by gravity separation. PMID:23558183

  13. Design and demonstration of an immobilized-cell fluidized-bed reactor for the efficient production of ethanol

    SciTech Connect

    Webb, O.F.; Scott, T.C.; Davison, B.H.; Scott, C.D.

    1994-06-01

    Initial studies have been carried out using a 4 inch ID fluidized bed reactor (FBR). This medium scale FBR was designed for scale-up. Present performance was compared with results from experiments using smaller FBRs. On-line and off-line measurement systems are also described. Zymomonas mobilis was immobilized in {kappa}-carrageenan at cell loadings of 15--50 g (dry weight) L{sup {minus}1}. The system is designed for determining optimal operation with high conversion and productivity for a variety of conditions including feedstocks, temperature, flow rate, and column sizes (from 2 to 5 meters tall). The demonstration used non-sterile feedstocks containing either industrial (light steep water) or synthetic nutrients and dextrose.

  14. Production of extracellular polysaccharides by the medicinal mushroom Trametes trogii (higher Basidiomycetes) in stirred-tank and airlift reactors.

    PubMed

    Xu, Chunping; Geng, Lujing; Zhang, Wenye

    2013-01-01

    Extracellular polysaccharides (EPSs) produced by submerged culture of Trametes trogii exhibit antioxidant and antitumor activities. In this study, mycelial growth and EPS production of T. trogii were investigated using optimal culture conditions (maltose [53.12 g/L] and polypeptone [4.21 g/L] in distilled water) in a 5-L jar fermenter. Maximum biomass growth (10.81 g/L) occurred after 5 days of cultivation, whereas maximal EPS yield (1.86 g/L) was achieved after 5 days in a 5-L stirred-tank reactor. Furthermore, the morphological parameters (i.e., mean diameter, circularity, roughness, and compactness) of the pellets and the viscosity of the broth were characterized. It was proved that the compactness of the pellets were significantly positively correlated with EPS content. PMID:23557370

  15. Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface

    SciTech Connect

    Joseph W. Newkirk; Richard K. Brow

    2010-01-21

    The overall goal of this project was to develop Ni-Si alloys for use in vessels to contain hot, pressurized sulfuric acid. The application was to be in the decomposition loop of the thermochemical cycle for production of hydrogen.

  16. Hydrogen production from banyan leaves using an atmospheric-pressure microwave plasma reactor.

    PubMed

    Lin, Yuan-Chung; Wu, Tzi-Yi; Jhang, Syu-Ruei; Yang, Po-Ming; Hsiao, Yi-Hsing

    2014-06-01

    Growth of the hydrogen market has motivated increased study of hydrogen production. Understanding how biomass is converted to hydrogen gas can help in evaluating opportunities for reducing the environmental impact of petroleum-based fuels. The microwave power used in the reaction is found to be proportional to the rate of production of hydrogen gas, mass of hydrogen gas produced per gram of banyan leaves consumed, and amount of hydrogen gas formed with respect to the H-atom content of banyan leaves decomposed. Increase the microwave power levels results in an increase of H2 and decrease of CO2 concentrations in the gaseous products. This finding may possibly be ascribed to the water-gas shift reaction. These results will help to expand our knowledge concerning banyan leaves and hydrogen yield on the basis of microwave-assisted pyrolysis, which will improve the design of hydrogen production technologies. PMID:24721492

  17. 10. Floor Layout of Thermal Hydraulics Laboratory, from The Thermal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Floor Layout of Thermal Hydraulics Laboratory, from The Thermal Hydraulics Laboratory at Hanford. General Electric Company, Hanford Atomic Products Operation, Richland, Washington, 1961. - D-Reactor Complex, Deaeration Plant-Refrigeration Buildings, Area 100-D, Richland, Benton County, WA

  18. The kinetics of inhibitor production resulting from hydrothermal deconstruction of wheat straw studied using a pressurised microwave reactor

    PubMed Central

    2014-01-01

    Background The use of a microwave synthesis reactor has allowed kinetic data for the hydrothermal reactions of straw biomass to be established from short times, avoiding corrections required for slow heating in conventional reactors, or two-step heating. Access to realistic kinetic data is important for predictions of optimal reaction conditions for the pretreatment of biomass for bioethanol processes, which is required to minimise production of inhibitory compounds and to maximise sugar and ethanol yields. Results The gravimetric loss through solubilisation of straw provided a global measure of the extent of hydrothermal deconstruction. The kinetic profiles of furan and lignin-derived inhibitors were determined in the hydrothermal hydrolysates by UV analysis, with concentrations of formic and acetic acid determined by HPLC. Kinetic analyses were either carried out by direct fitting to simple first order equations or by numerical integration of sequential reactions. Conclusions A classical Arrhenius activation energy of 148 kJmol−1 has been determined for primary solubilisation, which is higher than the activation energy associated with historical measures of reaction severity. The gravimetric loss is primarily due to depolymerisation of the hemicellulose component of straw, but a minor proportion of lignin is solubilised at the same rate and hence may be associated with the more hydrophilic lignin-hemicellulose interface. Acetic acid is liberated primarily from hydrolysis of pendant acetate groups on hemicellulose, although this occurs at a rate that is too slow to provide catalytic enhancement to the primary solubilisation reactions. However, the increase in protons may enhance secondary reactions leading to the production of furans and formic acid. The work has suggested that formic acid may be formed under these hydrothermal conditions via direct reaction of sugar end groups rather than furan breakdown. However, furan degradation is found to be significant, which may limit ultimate quantities generated in hydrolysate liquors. PMID:24678822

  19. Impact of organic loading rate on biohydrogen production in an up-flow anaerobic packed bed reactor (UAnPBR).

    PubMed

    Ferraz, Antônio Djalma Nunes; Zaiat, Marcelo; Gupta, Medhavi; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George

    2014-07-01

    This study assesses the impact of organic loading rate on biohydrogen production from glucose in an up-flow anaerobic packed bed reactor (UAnPBR). Two mesophilic UAPBRs (UAnPBR1 and 2) were tested at organic loading rates (OLRs) ranging from 6.5 to 51.4 g COD L(-1)d(-1). To overcome biomass washout, design modifications were made in the UAnPBR2 to include a settling zone to capture the detached biomass. The design modifications in UAnPBR2 increased the average hydrogen yield from 0.98 to 2.0 mol-H2 mol(-1)-glucose at an OLR of 25.7 g COD L(-1)d(-1). Although, a maximum hydrogen production rate of 23.4 ± 0.9 L H2 L(-1)d(-1) was achieved in the UAnPBR2 at an OLR of 51.4 g COD L(-1)d(-1), the hydrogen yield dropped by 50% to around 1 mol-H2 mol(-1)-glucose. The microbiological analysis (PCR/DGGE) showed that the biohydrogen production was due to the presence of the hydrogen and volatile acid producers such as Clostridium beijerinckii, Clostridium butyricum, Megasphaera elsdenii and Propionispira arboris. PMID:24865326

  20. The production of pure pressurised hydrogen by the reformer-steam iron process in a fixed bed reactor system

    NASA Astrophysics Data System (ADS)

    Nestl, Stephan; Voitic, Gernot; Lammer, Michael; Marius, Bernhard; Wagner, Julian; Hacker, Viktor

    2015-04-01

    In this paper a fixed bed chemical looping process for the decentralised production of pure pressurised hydrogen for fuel cell applications is described. CH4 is converted to a syngas using conventional steam reforming. The syngas is directly used for the reduction of an iron based oxygen carrier. A consecutive oxidation step using steam leads to the formation of pure pressurised hydrogen. A thermodynamic analysis was performed in order to investigate feasible conditions for the syngas generation and reduction step. Experiments using pure hydrogen as well as an artificial syngas mixture showed the feasibility of the process for the production of pressurised hydrogen. A stable hydrogen production at a pressure of 8-11 bar(g) was achieved and only minor impurities of 700 ppm of carbon dioxide but no signs of carbon monoxide were detected in the produced hydrogen. Although the active surface decreased from 7.5 m2 g-1 to 0.9 m2 g-1 only moderate losses of reactivity were measured in the fixed bed reactor. Thermogravimetric analysis showed a loss of 9% of reactive material over nine cycles, presumably due to sintering effects.

  1. Bagasse hydrolyzates from Agave tequilana as substrates for succinic acid production by Actinobacillus succinogenes in batch and repeated batch reactor.

    PubMed

    Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo

    2016-04-01

    The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh. PMID:26802183

  2. Development of a phenomena identification and ranking table for thermal-hydraulic phenomena during a double-ended guillotine break LOCA in an SRS production reactor

    SciTech Connect

    Hanson, R.G.; Ortiz, M.G.; Bolander, M.A.; Wilson, G.E.

    1989-07-01

    A rising level of scrutiny is being directed toward the Savannah River Site (SRS) production reactors. Improved calculational capabilities are being developed to provide a best estimate analytical process to determine the safe operating margins of the reactors. The Code Scaling, Applicability, and Uncertainty (CSAU) methodology, developed by the US Nuclear Regulatory Commission to support best estimate simulations, is being applied to the best estimate limits analysis for the SRS production reactors. One of the foundational parts of the method is the identification and ranking of all the processes that occur during the specific limiting scenario. The phenomena ranking is done according to their importance to safety criteria during the transient and is used to focus the uncertainty analysis on a sufficient, yet cost effective scope of work. This report documents the thermal-hydraulic phenomena that occur during a limiting break in an SRS production reactor and their importance to the uncertainty in simulations of the reactor behavior. 9 refs., 14 figs., 10 tabs.

  3. Continuous ethanol production from nonsterilized carob pod extract by immobilized Saccharomyces cerevisiae on mineral kissiris using a two-reactor system

    SciTech Connect

    Roukas, T.

    1996-06-01

    The continuous production of ethanol from nonsterilized carob pod extract by immobilized Saccharomyces cerevisiae on mineral kissiris using one- and two-reactor systems has been investigated. A maximum ethanol productivity of 9.6 g/L/h was obtained at an initial sugar concentration of 200 g/L and D = 0.4 h{sup -1} with 68% of theoretical yield and 34% of sugar utilization using the one-reactor system. At S{sub 0} = 200 g/L, D = 0.05 h{sup -1}, 83% of theoretical yield, and 64% of sugar utilization, an ethanol productivity of 2.6 g/L/h was achieved. In the two-reactor system, a maximum ethanol productivity of 11.4 g/L/h was obtained at S{sub 0} = 200 g/L and D = 0.4 h{sup -1} with 68.5% of theoretical yield and 41.5% of sugar utilization. The two-reactor system was operated at a constant dilution rate of 0.3 h{sup -1} for 60 d without loss of the original immobilized yeast activity. In this case, the average ethanol productivity, ethanol yield (% of theoretical), and sugar utilization were 10.7 g/L/h, 71.5%, and 48%, respectively. 18 refs., 3 figs.

  4. Optimization of biodiesel production in a hydrodynamic cavitation reactor using used frying oil.

    PubMed

    Ghayal, Dyneshwar; Pandit, Aniruddha B; Rathod, Virendra K

    2013-01-01

    The present work demonstrates the application of a hydrodynamic cavitation reactor for the synthesis of biodiesel with used frying oil as a feedstock. The synthesis involved the transesterification of used frying oil (UFO) with methanol in the presence of potassium hydroxide as a catalyst. The effect of geometry and upstream pressure of a cavitating orifice plate on the rate of transesterification reaction has been studied. It is observed that the micro level turbulence created by hydrodynamic cavitation somewhat overcomes the mass transfer limitations for triphasic transesterification reaction. The significant effects of upstream pressure on the rate of formation of methyl esters have been seen. It has been observed that flow geometry of orifice plate plays a crucial role in process intensification. With an optimized plate geometry of 2mm hole diameter and 25 holes, more than 95% of triglycerides have been converted to methyl esters in 10 min of reaction time with cavitational yield of 1.28 × 10(-3) (Grams of methyl esters produced per Joule of energy supplied). The potential of UFO to produce good quality methyl esters has been demonstrated. PMID:22922070

  5. Tar Production from Biomass Pyrolysis in a Fluidized Bed Reactor: A Novel Turbulent Multiphase Flow Formulation

    NASA Technical Reports Server (NTRS)

    Bellan, J.; Lathouwers, D.

    2000-01-01

    A novel multiphase flow model is presented for describing the pyrolysis of biomass in a 'bubbling' fluidized bed reactor. The mixture of biomass and sand in a gaseous flow is conceptualized as a particulate phase composed of two classes interacting with the carrier gaseous flow. The solid biomass is composed of three initial species: cellulose, hemicellulose and lignin. From each of these initial species, two new solid species originate during pyrolysis: an 'active' species and a char, thus totaling seven solid-biomass species. The gas phase is composed of the original carrier gas (steam), tar and gas; the last two species originate from the volumetric pyrolysis reaction. The conservation equations are derived from the Boltzmann equations through ensemble averaging. Stresses in the gaseous phase are the sum of the Newtonian and Reynolds (turbulent) contributions. The particulate phase stresses are the sum of collisional and Reynolds contributions. Heat transfer between phases, and heat transfer between classes in the particulate phase is modeled, the last resulting from collisions between sand and biomass. Closure of the equations must be performed by modeling the Reynolds stresses for both phases. The results of a simplified version (first step) of the model are presented.

  6. ELIXYS - a fully automated, three-reactor high-pressure radiosynthesizer for development and routine production of diverse PET tracers

    PubMed Central

    2013-01-01

    Background Automated radiosynthesizers are vital for routine production of positron-emission tomography tracers to minimize radiation exposure to operators and to ensure reproducible synthesis yields. The recent trend in the synthesizer industry towards the use of disposable kits aims to simplify setup and operation for the user, but often introduces several limitations related to temperature and chemical compatibility, thus requiring reoptimization of protocols developed on non-cassette-based systems. Radiochemists would benefit from a single hybrid system that provides tremendous flexibility for development and optimization of reaction conditions while also providing a pathway to simple, cassette-based production of diverse tracers. Methods We have designed, built, and tested an automated three-reactor radiosynthesizer (ELIXYS) to provide a flexible radiosynthesis platform suitable for both tracer development and routine production. The synthesizer is capable of performing high-pressure and high-temperature reactions by eliminating permanent tubing and valve connections to the reaction vessel. Each of the three movable reactors can seal against different locations on disposable cassettes to carry out different functions such as sealed reactions, evaporations, and reagent addition. A reagent and gas handling robot moves sealed reagent vials from storage locations in the cassette to addition positions and also dynamically provides vacuum and inert gas to ports on the cassette. The software integrates these automated features into chemistry unit operations (e.g., React, Evaporate, Add) to intuitively create synthesis protocols. 2-Deoxy-2-[18F]fluoro-5-methyl-β-l-arabinofuranosyluracil (l-[18F]FMAU) and 2-deoxy-2-[18F]fluoro-β-d-arabinofuranosylcytosine (d-[18F]FAC) were synthesized to validate the system. Results l-[18F]FMAU and d-[18F]FAC were successfully synthesized in 165 and 170 min, respectively, with decay-corrected radiochemical yields of 46% ± 1% (n = 6) and 31% ± 5% (n = 6), respectively. The yield, repeatability, and synthesis time are comparable to, or better than, other reports. d-[18F]FAC produced by ELIXYS and another manually operated apparatus exhibited similar biodistribution in wild-type mice. Conclusion The ELIXYS automated radiosynthesizer is capable of performing radiosyntheses requiring demanding conditions: up to three reaction vessels, high temperatures, high pressures, and sensitive reagents. Such flexibility facilitates tracer development and the ability to synthesize multiple tracers on the same system without customization or replumbing. The disposable cassette approach simplifies the transition from development to production. PMID:23849185

  7. Production of transplutonium elements in the high flux isotope reactor (HFIR)

    SciTech Connect

    Bigelow, J.E.; Corbett, B.L.; King, L.J.; McGuire, S.C.; Sims, T.M.

    1980-01-01

    The techniques described have been demonstrated to be adequate to predict the contents of transplutonium element production targets which have been irradiated in the HFIR. The deviations, at least for isotopes of mass 253 or less, are generally within the usual analytical uncertainties, or else are for isiotopes which are of little overall import to the program. Work is especially needed to get a better picture of the production of /sup 250/Cm, /sup 254/Es, /sup 255/Es, and ultimately /sup 257/Fm, since researchers are frequently stating their interest in obtaining larger quantities of these rare and difficult-to-produce nuclides.

  8. MANTRA: An Integral Reactor Physics Experiment to Infer the Neutron Capture Cross Sections of Actinides and Fission Products in Fast and Epithermal Spectra

    NASA Astrophysics Data System (ADS)

    Youinou, G.; Vondrasek, R.; Veselka, H.; Salvatores, M.; Paul, M.; Pardo, R.; Palmiotti, G.; Palchan, T.; Nusair, O.; Nimmagadda, J.; Nair, C.; Murray, P.; Maddock, T.; Kondrashev, S.; Kondev, F. G.; Jones, W.; Imel, G.; Glass, C.; Fonnesbeck, J.; Berg, J.; Bauder, W.

    2014-05-01

    This paper presents an update of an on-going collaborative INL-ANL-ISU integral reactor physics experiment whose objective is to infer the effective neutron capture cross sections for most of the actinides of importance for reactor physics and fuel cycle studies in both fast and epithermal spectra. Some fission products are also being considered. The principle of the experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation together with the neutron fluence will allow inference of effective neutron capture cross-sections in different neutron spectra.

  9. Biohydrogen production from Tequila vinasses in an anaerobic sequencing batch reactor: effect of initial substrate concentration, temperature and hydraulic retention time.

    PubMed

    Buitrón, Germán; Carvajal, Carolina

    2010-12-01

    The effect of the temperature (25 and 35 degrees C), the hydraulic retention time, HRT, (12 and 24 h) and initial substrate concentration on hydrogen production from Tequila vinasse was studied using a sequencing batch reactor. When 25 degrees C and 12-h HRT were applied, only insignificant biogas quantities were produced; however, using 24 h of HRT and temperatures of 25 and 35 degrees C, biogas containing hydrogen was produced. A maximum volumetric hydrogen production rate of 50.5 mL H(2) L(-1) h(-1) (48 mmol H(2) L(reactor)(-1) d(-1)) and an average hydrogen content in the biogas of 29.2+/-8.8% were obtained when the reactor was fed with 3 g COD L(-1), at 35 degrees C and 12-h HRT. Methane formation was observed when the longer HRT was applied. Results demonstrated the feasibility to produce hydrogen from this waste without a previous pre-treatment. PMID:20655747

  10. Inspection of surveillance equipment and activities at DOE Field Office, Richland

    SciTech Connect

    Not Available

    1991-09-30

    The purpose of this inspection was to review surveillance activities by the Department of Energy's (DOE) Field Office, Richland (RL) and contractor employees at the RL Hanford site for efficiency and economy and compliance with laws and regulations. The scope included surveillance activities, procedures, training, types of surveillance equipment, and management controls over the equipment and activities. We also looked at Departmental policies and procedures regarding the equipment and activities. Allegations of illegal surveillance that came to our attention during the course of this inspection were referred to the Department of Justice. As part of our review, inspectors were on-site at RL from February 11, 1991, through March 1, 1991. Follow-up trips to RL were also made in April, May, and June 1991. We also conducted interviews at Albuquerque, Savannah River, and Germantown of former RL employees and RL contractors who were on travel. Officials from DOE's Office of General Counsel (OGC), Office of Security Affairs, and Office of Safeguards and Security (S S) were also interviewed regarding the Department's purchase and possession of wiretapping and eavesdropping devices. We obtained 75 signed sworn statements from 55 individuals during the course of the inspection. 1 fig., 1 tab.

  11. Sludge stabilization at the Plutonium Finishing Plant, Hanford Site, Richland, Washington

    SciTech Connect

    Not Available

    1994-10-01

    This Environmental Assessment evaluates the proposed action to operate two laboratory-size muffle furnaces in glovebox HC-21C, located in the Plutonium Finishing Plant (PFP), Hanford Site, Richland, Washington. The muffle furnaces would be used to stabilize chemically reactive sludges that contain approximately 25 kilograms (55 pounds) of plutonium by heating to approximately 500 to 1000{degrees}C (900 to 1800{degrees}F). The resulting stable powder, mostly plutonium oxide with impurities, would be stored in the PFP vaults. The presence of chemically reactive plutonium-bearing sludges in the process gloveboxes poses a risk to workers from radiation exposure and limits the availability of storage space for future plant cleanup. Therefore, there is a need to stabilize the material into a form suitable for long-term storage. This proposed action would be an interim action, which would take place prior to completion of an Environmental Impact Statement for the PFP which would evaluate stabilization of all plutonium-bearing materials and cleanout of the facility. However, only 10 percent of the total quantity of plutonium in reactive materials is in the sludges, so this action will not limit the choice of reasonable alternatives or prejudice the Record of Decision of the Plutonium Finishing Plant Environmental Impact Statement.

  12. EFFICACY OF COMMERCIAL PRODUCTS IN ENHANCING OIL BIODEGRADATION IN CLOSED LABORATORY REACTORS

    EPA Science Inventory

    A laboratory screening protocol was designed and conducted to test the efficacy of eight commercial bacterial cultures and two non-bacterial products in enhancing the biodegradation of weathered Alaska North Slope crude oil in closed flasks. Three lines of evidence were used to ...

  13. A Fisheries Evaluation of the Richland and Toppenish/Satus Canal Fish Screening Facilities, Spring 1986 Annual Report.

    SciTech Connect

    Neitzel, D.A.; Abernethy, C. Scott; Lusty, E. William

    1987-05-01

    The fisheries evaluation phase of diversion screen effectiveness summarizes the results of work at the Richland and Toppenish/Satus Fish screening facilities (Richland Screens and Toppenish/Satus Screens) during 1986. More than 10,000 steelhead, Salmo gairdneri, and chinook salmon, Oncorhynchus tshawytscha, were released at the screen diversions. At the Richland Screens, 61% of the released steelhead were recovered and 1.1% were descaled; 93% of the spring chinook salmon were recovered and less than 1% were descaled. At the Toppenish/Satus Screens, only steelhead were evaluated for descaling; 88.9% were recovered and 23.9% were descaled. Only steelhead were evaluated because the Yakima River fisheries managers did not expect any other smolts to occur in Toppenish Creek. Because of the acclimation conditions and the amount of time the fish had to be held before testing, some of the test population were descaled during holding and transportation. The 23.9% descaling for the test fish was compared to 26.4% for the controls.

  14. Mass spectrometry studies of fission product behavior: 1, Fission products released from irradiated LWR (light-water reactor) fuel

    SciTech Connect

    Johnson, I.; Johnson, C.E.

    1987-01-01

    The chemical form and rate of release of volatile fission products (i.e., Xe, Kr, Cs, Te, I...) effused from an irradiated LWR fuel pin sample were studied using quadrupole mass spectrometry. Experiments, up to a temperature of 2120 K, 2060 K have identified krypton, xenon, cesium, and tellurium as the species released from the fuel. In addition, there was a weak signal for atomic iodine at 1325 K. The source of the atomic iodine, e.g. dissociation of cesium iodine or dissociation of molecular iodine, has yet to be resolved. The observed rate of release of xenon was several orders of magnitude lower than previously reported. However, the xenon release rate increased significantly after the fuel was oxidized. In complementary experiments on nonradioactive material, the release of tellurium was hindered by reaction with Zircaloy cladding. Above 1300/sup 0/C, gaseous SnTe was observed; its formation is attributed to reaction of the tin (in the cladding) with ZrTe/sub 2/. 4 refs., 5 figs.

  15. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    SciTech Connect

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  16. Toward highly-effective and sustainable hydrogen production: bio-ethanol oxidative steam reforming coupled with water splitting in a thin tubular membrane reactor.

    PubMed

    Zhu, Na; Dong, Xueliang; Liu, Zhengkun; Zhang, Guangru; Jin, Wanqin; Xu, Nanping

    2012-07-21

    Highly-effective sustainable hydrogen production from ethanol and water was achieved in a tubular dense mixed-conducting oxygen permeable membrane reactor, in which water splitting took place at the tube side of the membrane and oxidative steam reforming of ethanol occurred at the shell side simultaneously. PMID:22428158

  17. Biogas production from wheat straw in batch and UASB reactors: the roles of pretreatment and seaweed hydrolysate as a co-substrate.

    PubMed

    Nkemka, Valentine Nkongndem; Murto, Marika

    2013-01-01

    This research evaluated biogas production in batch and UASB reactors from pilot-scale acid catalysed steam pretreated and enzymatic hydrolysed wheat straw. The results showed that the pretreatment was efficient and, a sugar yield of 95% was obtained. The pretreatment improved the methane yield (0.28 m(3)/kg VS(added)) by 57% compared to untreated straw. Treatment of the straw hydrolysate with nutrient supplementation in a UASB reactor resulted in a high methane production rate, 2.70 m(3)/m(3).d at a sustainable OLR of 10.4 kg COD/m(3).d and with a COD reduction of 94%. Alternatively, co-digestion of the straw and seaweed hydrolysates in a UASB reactor also maintained a stable anaerobic process and can thus reduce the cost of nutrients addition. We have shown that biogas production from wheat straw can be competitive by pretreatment, high methane production rate in UASB reactors and also by co-digestion with seaweed hydrolysate. PMID:23196235

  18. Application of sequential expanded granular sludge bed reactors for biodegradation of acetate, benzoate, terephtalate and p-toluate in purified terephtalic acid production wastewater.

    PubMed

    Lee, Y S; Han, G B

    2016-05-01

    The anaerobic degradation of four major constituents from purified terephtalic acid production wastewater in sequential two expanded granular sludge bed (EGSB) reactors was studied. The performance of the system was evaluated in terms of chemical oxygen demand (COD) removal efficiencies, methane production, stability, granular sludge adaptability as well as reversion of bacterial inhibition. With volumetric loading rates of 1.9-25 kg-COD m(-3) d(-1) and terephtalate and p-toluate of 584-821 mg L(-1), average removal efficiencies of 97.6% and 75.2% were achieved in the EGSB reactors, respectively. In these conditions, gas production reached a total methane production rate of 0.33 L g-COD(-1) in the two-stage EGSB reactor system. The disturbance of the EGSB reactors was observed at a feed concentration above around 6.9 g-COD L(-1) because of higher influent COD concentration compared to other experiments. PMID:26513246

  19. High solids fermentation reactor

    DOEpatents

    Wyman, Charles E.; Grohmann, Karel; Himmel, Michael E.; Richard, Christopher J.

    1993-03-02

    A fermentation reactor and method for fermentation of materials having greater than about 10% solids. The reactor includes a rotatable shaft along the central axis, the shaft including rods extending outwardly to mix the materials. The reactor and method are useful for anaerobic digestion of municipal solid wastes to produce methane, for production of commodity chemicals from organic materials, and for microbial fermentation processes.

  20. High solids fermentation reactor

    DOEpatents

    Wyman, Charles E.; Grohmann, Karel; Himmel, Michael E.; Richard, Christopher J.

    1993-01-01

    A fermentation reactor and method for fermentation of materials having greater than about 10% solids. The reactor includes a rotatable shaft along the central axis, the shaft including rods extending outwardly to mix the materials. The reactor and method are useful for anaerobic digestion of municipal solid wastes to produce methane, for production of commodity chemicals from organic materials, and for microbial fermentation processes.

  1. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    SciTech Connect

    Mahesh Iyer; Shwetha Ramkumar; Liang-Shih Fan

    2006-03-31

    Hydrogen production from coal gasification can be enhanced by driving the equilibrium limited Water Gas Shift reaction forward by incessantly removing the CO{sub 2} by-product via the carbonation of calcium oxide. This project uses the high-reactivity mesoporous precipitated calcium carbonate sorbent for removing the CO{sub 2} product to enhance H{sub 2} production. Preliminary experiments demonstrate the show the superior performance of the PCC sorbent over other naturally occurring calcium sorbents. It was observed that the CO{sub 2} released during the in-situ calcination causes the deactivation of the iron oxide WGS catalyst by changing the active phase of the catalyst from magnetite (F{sub 3}O{sub 4}). Detailed understanding of the iron oxide phase diagram helped in developing a catalyst pretreatment procedure using a H{sub 2}/H{sub 2}O system. Intermediate catalyst pretreatment helps prevent its deactivation by reducing the catalyst back to its active magnetite (Fe{sub 3}O{sub 4}) form. Multicyclic runs which consist of combined WGS/carbonation reaction followed by in-situ calcination with a subsequent catalyst pretreatment procedure sustains the catalytic activity and prevents deactivation. The water gas shift reaction was studied at different temperatures, different steam to carbon monoxide ratios (S/C) 3:1, 2:1, 1:1 and different total pressures ranging from 0-300 psig. The CO conversion was found to have an optimal value with increasing pressure, S/C ratio and temperatures. The combined water gas shift and carbonation reaction was investigated at 650 C, S/C ratio of 3:1and at different pressures of 0-300 psig.

  2. Efficient production of methane from artificial garbage waste by a cylindrical bioelectrochemical reactor containing carbon fiber textiles.

    PubMed

    Sasaki, Daisuke; Sasaki, Kengo; Watanabe, Atsushi; Morita, Masahiko; Igarashi, Yasuo; Ohmura, Naoya

    2013-01-01

    A cylindrical bioelectrochemical reactor (BER) containing carbon fiber textiles (CFT; BER + CFT) has characteristics of bioelectrochemical and packed-bed systems. In this study, utility of a cylindrical BER + CFT for degradation of a garbage slurry and recovery of biogas was investigated by applying 10% dog food slurry. The working electrode potential was electrochemically regulated at -0.8 V (vs. Ag/AgCl). Stable methane production of 9.37 L-CH4 · L-1 · day-1 and dichromate chemical oxygen demand (CODcr) removal of 62.5% were observed, even at a high organic loading rate (OLR) of 89.3 g-CODcr · L-1 · day-1. Given energy as methane (372.6 kJ · L-1 · day-1) was much higher than input electric energy to the working electrode (0.6 kJ · L-1 · day-1) at this OLR. Methanogens were highly retained in CFT by direct attachment to the cathodic working electrodes (52.3%; ratio of methanogens to prokaryotes), compared with the suspended fraction (31.2%), probably contributing to the acceleration of organic material degradation and removal of organic acids. These results provide insight into the application of cylindrical BER + CFT in efficient methane production from garbage waste including a high percentage of solid fraction. PMID:23497472

  3. Improvement of hydrogen production via ethanol-type fermentation in an anaerobic down-flow structured bed reactor.

    PubMed

    Anzola-Rojas, Mélida Del Pilar; Zaiat, Marcelo; De Wever, Heleen

    2016-02-01

    Although a novel anaerobic down-flow structured bed reactor has shown feasibility and stable performance for a long-term compared to other anaerobic fixed bed systems for continuous hydrogen production, the volumetric rates and yields have so far been too low. In order to improve the performance, an operation strategy was applied by organic loading rate (OLR) variation (12-96gCODL(-1)d(-1)). Different volumetric hydrogen rates, and yields at the same OLR indicated that the system was mainly driven by the specific organic load (SOL). When SOL was kept between 3.8 and 6.2g sucrose g(-1)VSSd(-1), the volumetric rates raised from 0.1 to 8.9LH2L(-1)d(-1), and the yields were stable around 2.0molH2mol(-1) converted sucrose. Furthermore, hydrogen was produced mainly via ethanol-type fermentation, reaching a total energy conversion rate of 23.40kJh(-1)L(-1) based on both hydrogen and ethanol production. PMID:26700757

  4. Catalytic pyrolysis of Alcea pallida stems in a fixed-bed reactor for production of liquid bio-fuels.

    PubMed

    Aysu, Tevfik

    2015-09-01

    Pyrolysis of Alcea pallida stems was performed in a fixed-bed tubular reactor with and without catalyst at three different temperatures. The effects of pyrolysis parameters including temperature and catalyst on the product yields were investigated. It was found that higher temperature resulted in lower liquid (bio-oil) and solid (bio-char) yields and higher gas yields. Catalysts had different effects on product yields and composition of bio-oils. Liquid yields were increased in the presence of zinc chloride and alumina but decreased with calcium hydroxide, tincal and ulexite. The highest bio-oil yield (39.35%) by weight including aqueous phase was produced with alumina catalyst at 500 °C. The yields of bio-char, bio-oil and gas produced, as well as the compositions of the resulting bio-oils were determined by elemental analysis, TGA, FT-IR and GC-MS. 160 different compounds were identified by GC-MS in the bio-oils obtained at 500 °C. PMID:26000835

  5. Impact of Fission Products Impurity on the Plutonium Content of Metal- and Oxide- Fuels in Sodium Cooled Fast Reactors

    SciTech Connect

    Hikaru Hiruta; Gilles Youinou

    2013-09-01

    This short report presents the neutronic analysis to evaluate the impact of fission product impurity on the Pu content of Sodium-cooled Fast Reactor (SFR) metal- and oxide- fuel fabrication. The similar work has been previously done for PWR MOX fuel [1]. The analysis will be performed based on the assumption that the separation of the fission products (FP) during the reprocessing of UOX spent nuclear fuel assemblies is not perfect and that, consequently, a certain amount of FP goes into the Pu stream used to fabricate SFR fuels. Only non-gaseous FPs have been considered (see the list of 176 isotopes considered in the calculations in Appendix 1 of Reference 1). Throughout of this report, we define the mixture of Pu and FPs as PuFP. The main objective of this analysis is to quantify the increase of the Pu content of SFR fuels necessary to maintain the same average burnup at discharge independently of the amount of FP in the Pu stream, i.e. independently of the PuFP composition. The FP losses are considered element-independent, i.e., for example, 1% of FP losses mean that 1% of all non-gaseous FP leak into the Pu stream.

  6. Tokamak reactor studies

    SciTech Connect

    Baker, C.C.

    1981-01-01

    This paper presents an overview of tokamak reactor studies with particular attention to commercial reactor concepts developed within the last three years. Emphasis is placed on DT fueled reactors for electricity production. A brief history of tokamak reactor studies is presented. The STARFIRE, NUWMAK, and HFCTR studies are highlighted. Recent developments that have increased the commercial attractiveness of tokamak reactor designs are discussed. These developments include smaller plant sizes, higher first wall loadings, improved maintenance concepts, steady-state operation, non-divertor particle control, and improved reactor safety features.

  7. Ultimate Safe (US) Reactor

    SciTech Connect

    Gat, U.; Daugherty, S.R.

    1985-01-01

    The Ultimate Safe (US) Reactor is a reactor that eliminates the traditional safety concerns of nuclear fission reactors. The US reactor has an insignificant source term and no reasonable criticality accident. Furthermore, the negligible residual after-heat in the reactor renders its shutdown capability comparable or superior to conventional power sources. Fission products are continuously removed at the rate they are produced. The reactor is operated with no excess criticality, hence no criticality accident is reasonably possible. The reactor is controlled safely by its negative temperature coeffiient. The reactor maintains criticality by an internal breeding ratio that is trimmed to be exactly one. The US reactor requires a fluid fuel and on-line, continuous fuel processing. Molten salt fuel was selected for its low vapor pressure at high temperature; adequate solubility of uranium and thorium as fluorides; good compatibility with structural materials; absence of irradiation damage; high negative temperature coefficient and amply developed technology and experience.

  8. A MODEL FOR PREDICTING FISSION PRODUCT ACTIVITIES IN REACTOR COOLANT: APPLICATION OF MODEL FOR ESTIMATING I-129 LEVELS IN RADIOACTIVE WASTE

    SciTech Connect

    Lewis, B.J.; Husain, A.

    2003-02-27

    A general model was developed to estimate the activities of fission products in reactor coolant and hence to predict a value for the I-129/Cs-137 scaling factor; the latter can be applied along with measured Cs-137 activities to estimate I-129 levels in reactor waste. The model accounts for fission product release from both defective fuel rods and uranium contamination present on in-core reactor surfaces. For simplicity, only the key release mechanisms were modeled. A mass balance, considering the two fuel source terms and a loss term due to coolant cleanup was solved to estimate fission product activity in the primary heat transport system coolant. Steady state assumptions were made to solve for the activity of shortlived fission products. Solutions for long-lived fission products are time-dependent. Data for short-lived radioiodines I-131, I-132, I-133, I-134 and I-135 were analyzed to estimate model parameters for I-129. The estimated parameter values were then used to determine I-1 29 coolant activities. Because of the chemical affinity between iodine and cesium, estimates of Cs-137 coolant concentrations were also based on parameter values similar to those for the radioiodines; this assumption was tested by comparing measured and predicted Cs-137 coolant concentrations. Application of the derived model to Douglas Point and Darlington Nuclear Generating Station plant data yielded estimates for I-129/I-131 and I-129/Cs-137 which are consistent with values reported for pressurized water reactors (PWRs) and boiling water reactors (BWRs). The estimated magnitude for the I-129/Cs-137 ratio was 10-8 - 10-7.

  9. Startup of the FFTF sodium cooled reactor. [Acceptance Test Program

    SciTech Connect

    Redekopp, R.D.; Umek, A.M.

    1981-03-01

    The Fast Flux Test Facility (FFTF), located on the Department of Energy (DOE) Hanford Reservation near Richland, Washington, is a 3 Loop 400 MW(t) sodium cooled fast reactor with a primary mission to test fuels and materials for development of the Liquid Metal Fast Breeder Reactor (LMFBR). Bringing FFTF to a condition to accomplish this mission is the goal of the Acceptance Test Program (ATP). This program was the mechanism for achieving startup of the FFTF. Highlights of the ATP involving the system inerting, liquid metal and inerted cell testing and initial ascent to full power are discussed.

  10. 28. A typical main control panel in a 105 reactor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. A typical main control panel in a 105 reactor building, in this case 105-F in February 1945. A single operator sat at the controls to regulate the pile's rate of reaction and monitor it for safety. The galvanometer screens (the two horizontal bars just below the nine round gauges that showed the positions of the control rods) showed the pile's current power setting. With that information, the operator could set the control rod positions to increase, decrease, or maintain the power. D-8310 - B Reactor, Richland, Benton County, WA

  11. NEUTRONIC REACTOR POWER PLANT

    DOEpatents

    Metcalf, H.E.

    1962-12-25

    This patent relates to a nuclear reactor power plant incorporating an air-cooled, beryllium oxide-moderated, pebble bed reactor. According to the invention means are provided for circulating a flow of air through tubes in the reactor to a turbine and for directing a sidestream of the circu1ating air through the pebble bed to remove fission products therefrom as well as assist in cooling the reactor. (AEC)

  12. Hydrocarbon pyrolysis reactor experimentation and modeling for the production of solar absorbing carbon nanoparticles

    NASA Astrophysics Data System (ADS)

    Frederickson, Lee Thomas

    Much of combustion research focuses on reducing soot particulates in emissions. However, current research at San Diego State University (SDSU) Combustion and Solar Energy Laboratory (CSEL) is underway to develop a high temperature solar receiver which will utilize carbon nanoparticles as a solar absorption medium. To produce carbon nanoparticles for the small particle heat exchange receiver (SPHER), a lab-scale carbon particle generator (CPG) has been built and tested. The CPG is a heated ceramic tube reactor with a set point wall temperature of 1100-1300°C operating at 5-6 bar pressure. Natural gas and nitrogen are fed to the CPG where natural gas undergoes pyrolysis resulting in carbon particles. The gas-particle mixture is met downstream with dilution air and sent to the lab scale solar receiver. To predict soot yield and general trends in CPG performance, a model has been setup in Reaction Design CHEMKIN-PRO software. One of the primary goals of this research is to accurately measure particle properties. Mean particle diameter, size distribution, and index of refraction are calculated using Scanning Electron Microscopy (SEM) and a Diesel Particulate Scatterometer (DPS). Filter samples taken during experimentation are analyzed to obtain a particle size distribution with SEM images processed in ImageJ software. These results are compared with the DPS, which calculates the particle size distribution and the index of refraction from light scattering using Mie theory. For testing with the lab scale receiver, a particle diameter range of 200-500 nm is desired. Test conditions are varied to understand effects of operating parameters on particle size and the ability to obtain the size range. Analysis of particle loading is the other important metric for this research. Particle loading is measured downstream of the CPG outlet and dilution air mixing point. The air-particle mixture flows through an extinction tube where opacity of the mixture is measured with a 532 nm laser and detector. Beer's law is then used to calculate particle loading. The CPG needs to produce a certain particle loading for a corresponding receiver test. By obtaining the particle loading in the system, the reaction conversion to solid carbon in the CPG can be calculated to measure the efficiency of the CPG. To predict trends in reaction conversion and particle size from experimentation, the CHEMKIN-PRO computer model for the CPG is run for various flow rates and wall temperature profiles. These predictions were a reason for testing at higher wall set point temperatures. Based on these research goals, it was shown that the CPG consistently produces a mean particle diameter of 200-400 nm at the conditions tested, fitting perfectly inside the desired range. This led to successful lab scale SPHER testing which produced a 10-point efficiency increase and 150°C temperature difference with particles present. Also, at 3 g/s dilution air flow rate, an efficiency of 80% at an outlet temperature above 800°C was obtained. Promise was shown at higher CPG experimental temperatures to produce higher reaction conversion, both experimentally and in the model. However, based on wall temperature data taken during experimentation, it is apparent that the CPG needs to have multiple heating zones with separate temperature controllers in order to have an isothermal zone rather than a parabolic temperature profile. As for the computer model, it predicted much higher reaction conversion at higher temperature. The mass fraction of fuel in the inlet stream was shown to not affect conversion while increasing residence time led to increasing conversion. Particle size distribution in the model was far off and showed a bimodal distribution for one of the statistical methods. Using the results from experimentation and modeling, a preliminary CPG design is presented that will operate in a 5MWth receiver system.

  13. Multiphysics Modeling for Dimensional Analysis of a Self-Heated Molten Regolith Electrolysis Reactor for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Dominguez, Jesus; Sibille, Laurent

    2010-01-01

    The technology of direct electrolysis of molten lunar regolith to produce oxygen and molten metal alloys has progressed greatly in the last few years. The development of long-lasting inert anodes and cathode designs as well as techniques for the removal of molten products from the reactor has been demonstrated. The containment of chemically aggressive oxide and metal melts is very difficult at the operating temperatures ca. 1600 C. Containing the molten oxides in a regolith shell can solve this technical issue and can be achieved by designing a self-heating reactor in which the electrolytic currents generate enough Joule heat to create a molten bath.

  14. Fusion power production in International Thermonuclear Experimental Reactor baseline H-mode scenarios

    NASA Astrophysics Data System (ADS)

    Rafiq, T.; Kritz, A. H.; Kessel, C. E.; Pankin, A. Y.

    2015-04-01

    Self-consistent simulations of 15 MA ITER H-mode DT scenarios, from ramp-up through flat-top, are carried out. Electron and ion temperatures, toroidal angular frequency, and currents are evolved, in simulations carried out using the predictive TRANSPort and integrated modeling code starting with initial profiles and equilibria obtained from tokamak simulation code studies. Studies are carried out examining the dependence and sensitivity of fusion power production on electron density, argon impurity concentration, choice of radio frequency heating, pedestal temperature without and with E × B flow shear effects included, and the degree of plasma rotation. The goal of these whole-device ITER simulations is to identify dependencies that might impact ITER fusion performance.

  15. Electrochemical enhancement of glucose oxidase kinetics : gluconic acid production with anion exchange membrane reactor.

    SciTech Connect

    Hestekin, J.A.; Lin, Y. P.; Frank, J.; Snyder, S.; St. Martin, E.; Energy Systems

    2002-09-01

    Enzyme-catalysed reactions provide a means to perform many industrial processes because they enhance chemical reactions specifically and avoid the formation of by-products and the use of toxic organic solvents. Current enzyme applications range from laundry detergent supplements to the destruction of nerve gas agents. Although enzyme specificity is attractive there are also significant disadvantages to enzymatic catalysis. One of the principal disadvantages being relatively short lifetimes, ranging from a few hours to several days. However, literature has shown that by immobilizing an enzyme on a support matrix, the lifetime of the enzyme is increased since the rigidity of the support matrix helps prevent unfolding. Microfiltration membranes are often a good choice for enzyme attachment. The high surface area in the pores allows for enzyme attachment and reduction of mass transfer limitations.

  16. Fusion power production in International Thermonuclear Experimental Reactor baseline H-mode scenarios

    SciTech Connect

    Rafiq, T.; Kritz, A. H.; Kessel, C. E.; Pankin, A. Y.

    2015-04-15

    Self-consistent simulations of 15 MA ITER H-mode DT scenarios, from ramp-up through flat-top, are carried out. Electron and ion temperatures, toroidal angular frequency, and currents are evolved, in simulations carried out using the predictive TRANSPort and integrated modeling code starting with initial profiles and equilibria obtained from tokamak simulation code studies. Studies are carried out examining the dependence and sensitivity of fusion power production on electron density, argon impurity concentration, choice of radio frequency heating, pedestal temperature without and with E × B flow shear effects included, and the degree of plasma rotation. The goal of these whole-device ITER simulations is to identify dependencies that might impact ITER fusion performance.

  17. Environmental restoration and waste management site-specific plan for Richland Operations Office. [Contains glossary

    SciTech Connect

    Not Available

    1991-09-01

    This document was prepared to implement and support the US Department of Energy-Headquarters (DOE-HQ) national plan. The national plan, entitled Environmental Restoration and Waste Management Five-Year Plan (DOE 1990b) (hereinafter referred to as the DOE-HQ Five-Year Plan) is the cornerstone of the US Department of Energy's (DOE) long-term strategy in environmental restoration and waste management. The DOE-HQ Five-Year Plan addresses overall philosophy and environmental and waste-related activities under the responsibilities of the DOE Office of Environmental Restoration and Waste Management. The plan also reaffirms DOE-HQ goals to bring its nuclear sites into environmental compliance in cooperation with its regulators and the public, and to clean up and restore the environment by 2019 (the commitment for the Hanford Site is for one year sooner, or 2018). This document is part of the site-specific plan for the US Department of Energy-Richland Operations Office (DOE-RL). It is the first revision of the original plan, which was dated December 1989 (DOE-RL 1989a). This document is a companion document to the Overview of the Hanford Cleanup Five-Year Plan (DOE-RL 1989d) and The Hanford Site Environmental Restoration and Waste Management Five-Year Plan Activity Data Sheets (DOE-RL 1991). Although there are three documents that make up the complete DOE-RL plan, this detailed information volume was prepared so it could be used as a standalone document. 71 refs., 40 figs., 28 tabs.

  18. Installation and Final Testing of an On-Line, Multi-Spectrometer Fission Product Monitoring System (FPMS) to Support Advanced Gas Reactor (AGR) Fuel Testing and Qualification in the Advanced Test Reactor

    SciTech Connect

    J. K. Hartwell; D. M. Scates; M. W. Drigert; J. B. Walter

    2006-10-01

    The US Department of Energy (DOE) is initiating tests of reactor fuel for use in an Advanced Gas Reactor (AGR). The AGR will use helium coolant, a low-power-density ceramic core, and coated-particle fuel. A series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). One important measure of fuel performance in these tests is quantification of the fission gas releases over the nominal 2-year duration of each irradiation experiment. This test objective will be met using the AGR Fission Product Monitoring System (FPMS) which includes seven (7) on-line detection stations viewing each of the six test capsule effluent lines (plus one spare). Each station incorporates both a heavily-shielded high-purity germanium (HPGe) gamma-ray spectrometer for quantification of the isotopic releases, and a NaI(Tl) scintillation detector to monitor the total count rate and identify the timing of the releases. The AGR-1 experiment will begin irradiation after October 1, 2006. To support this experiment, the FPMS has been completely assembled, tested, and calibrated in a laboratory at the INL, and then reassembled and tested in its final location in the ATR reactor basement. This paper presents the details of the equipment performance, the control and acquisition software, the test plan for the irradiation monitoring, and the installation in the ATR basement. Preliminary on-line data may be available by the Conference date.

  19. Development Program of IS Process Pilot Test Plant for Hydrogen Production With High-Temperature Gas-Cooled Reactor

    SciTech Connect

    Jin Iwatsuki; Atsuhiko Terada; Hiroyuki Noguchi; Yoshiyuki Imai; Masanori Ijichi; Akihiro Kanagawa; Hiroyuki Ota; Shinji Kubo; Kaoru Onuki; Ryutaro Hino

    2006-07-01

    At the present time, we are alarmed by depletion of fossil energy and effects on global environment such as acid rain and global warming, because our lives depend still heavily on fossil energy. So, it is universally recognized that hydrogen is one of the best energy media and its demand will be increased greatly in the near future. In Japan, the Basic Plan for Energy Supply and Demand based on the Basic Law on Energy Policy Making was decided upon by the Cabinet on 6 October, 2003. In the plan, efforts for hydrogen energy utilization were expressed as follows; hydrogen is a clean energy carrier without carbon dioxide (CO{sub 2}) emission, and commercialization of hydrogen production system using nuclear, solar and biomass, not fossil fuels, is desired. However, it is necessary to develop suitable technology to produce hydrogen without CO{sub 2} emission from a view point of global environmental protection, since little hydrogen exists naturally. Hydrogen production from water using nuclear energy, especially the high-temperature gas-cooled reactor (HTGR), is one of the most attractive solutions for the environmental issue, because HTGR hydrogen production by water splitting methods such as a thermochemical iodine-sulfur (IS) process has a high possibility to produce hydrogen effectively and economically. The Japan Atomic Energy Agency (JAEA) has been conducting the HTTR (High-Temperature Engineering Test Reactor) project from the view to establishing technology base on HTGR and also on the IS process. In the IS process, raw material, water, is to be reacted with iodine (I{sub 2}) and sulfur dioxide (SO{sub 2}) to produce hydrogen iodide (HI) and sulfuric acid (H{sub 2}SO{sub 4}), the so-called Bunsen reaction, which are then decomposed endo-thermically to produce hydrogen (H{sub 2}) and oxygen (O{sub 2}), respectively. Iodine and sulfur dioxide produced in the decomposition reactions can be used again as the reactants in the Bunsen reaction. In JAEA, continuous hydrogen production was demonstrated with the hydrogen production rate of about 30 NL/hr for one week using a bench-scale test apparatus made of glass. Based on the test results and know-how obtained through the bench-scale tests, a pilot test plant that can produce hydrogen of about 30 Nm{sup 3}/hr is being designed. The test plant will be fabricated with industrial materials such as glass coated steel, SiC ceramics etc, and operated under high pressure condition up to 2 MPa. The test plant will consist of a IS process plant and a helium gas (He) circulation facility (He loop). The He loop can simulate HTTR operation conditions, which consists of a 400 kW-electric heater for He hating, a He circulator and a steam generator working as a He cooler. In parallel to the design study, key components of the IS process such as the sulfuric acid (H{sub 2}SO{sub 4}) and the sulfur trioxide (SO{sub 3}) decomposers working under-high temperature corrosive environments have been designed and test-fabricated to confirm their fabricability. Also, other R and D's are under way such as corrosion, processing of HIx solutions. This paper describes present status of these activities. (authors)

  20. Environmental assessment of SP-100 ground engineering system test site: Hanford Site, Richland, Washington

    SciTech Connect

    Not Available

    1988-12-01

    The US Department of Energy (DOE) proposes to modify an existing reactor containment building (decommissioned Plutonium Recycle Test Reactor (PRTR) 309 Building) to provide ground test capability for the prototype SP-100 reactor. The 309 Building (Figure 1.1) is located in the 300 Area on the Hanford Site in Washington State. The National Environmental Policy Act (NEPA) requires that Federal agencies assess the potential impacts that their actions may have on the environment. This Environmental Assessment describes the consideration given to environmental impacts during reactor concept and test site selection, examines the environmental effects of the DOE proposal to ground test the nuclear subsystem, describes alternatives to the proposed action, and examines radiological risks of potential SP-100 use in space. 73 refs., 19 figs., 7 tabs.

  1. Production of medical radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for cancer treatment and arterial restenosis therapy after PTCA

    SciTech Connect

    Knapp, F.F. Jr.; Beets, A.L.; Mirzadeh, S.; Alexander, C.W.; Hobbs, R.L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  2. Production of Medical Radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for Cancer Treatment and Arterial Restenosis Therapy after PTCA

    DOE R&D Accomplishments Database

    Knapp, F. F. Jr.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  3. Production of fissioning uranium plasma to approximate gas-core reactor conditions

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Mcfarland, D. R.; Hohl, F.; Kim, K. H.

    1974-01-01

    The intense burst of neutrons from the d-d reaction in a plasma-focus apparatus is exploited to produce a fissioning uranium plasma. The plasma-focus apparatus consists of a pair of coaxial electrodes and is energized by a 25 kJ capacitor bank. A 15-g rod of 93% enriched U-235 is placed in the end of the center electrode where an intense electron beam impinges during the plasma-focus formation. The resulting uranium plasma is heated to about 5 eV. Fission reactions are induced in the uranium plasma by neutrons from the d-d reaction which were moderated by the polyethylene walls. The fission yield is determined by evaluating the gamma peaks of I-134, Cs-138, and other fission products, and it is found that more than 1,000,000 fissions are induced in the uranium for each focus formation, with at least 1% of these occurring in the uranium plasma.

  4. Biogas production from different substrates in an experimental Continuously Stirred Tank Reactor anaerobic digester.

    PubMed

    Fantozzi, Francesco; Buratti, Cinzia

    2009-12-01

    Different mixtures were digested in a single-stage, batch, mixed, laboratory scale mesophilic anaerobic digester at the Biomass Research Centre Laboratory (University of Perugia). The yield and the composition of biogas from the different substrates were evaluated and the cumulative curves were estimated. Two experimental campaigns were carried out, the first on three mixtures (chicken, pig and bovine manures), the second on animal and vegetal biomasses (chicken and cow manure, olive husk) with different inocula (rumen fluid and digested sludge). In the first campaign pig manure mixture showed the maximum biogas production (0.35 N m(3)/kg) and energy content (1.35 kWh/kg VS); in the second one the differences in produced biogas from the different inocula were analyzed: olive husk with piggery manure anaerobically digested as inoculum showed the higher biogas (0.28 N m(3)/kg VS) and methane yield (0.11 N m(3)/kg VS), corresponding to an energetic content of 1.07 kWh/kg VS. All data obtained from the laboratory scale anaerobic digester are comparable to the values in literature for several biomass and in particular for olive husk, dairy manure and chicken manure. PMID:19595588

  5. Biohydrogen and Bioethanol Production from Biodiesel-Based Glycerol by Enterobacter aerogenes in a Continuous Stir Tank Reactor.

    PubMed

    Jitrwung, Rujira; Yargeau, Viviane

    2015-01-01

    Crude glycerol from the biodiesel manufacturing process is being produced in increasing quantities due to the expanding number of biodiesel plants. It has been previously shown that, in batch mode, semi-anaerobic fermentation of crude glycerol by Enterobacter aerogenes can produce biohydrogen and bioethanol simultaneously. The present study demonstrated the possible scaling-up of this process from small batches performed in small bottles to a 3.6-L continuous stir tank reactor (CSTR). Fresh feed rate, liquid recycling, pH, mixing speed, glycerol concentration, and waste recycling were optimized for biohydrogen and bioethanol production. Results confirmed that E. aerogenes uses small amounts of oxygen under semi-anaerobic conditions for growth before using oxygen from decomposable salts, mainly NH4NO3, under anaerobic condition to produce hydrogen and ethanol. The optimal conditions were determined to be 500 rpm, pH 6.4, 18.5 g/L crude glycerol (15 g/L glycerol) and 33% liquid recycling for a fresh feed rate of 0.44 mL/min. Using these optimized conditions, the process ran at a lower media cost than previous studies, was stable after 7 days without further inoculation and resulted in yields of 0.86 mol H2/mol glycerol and 0.75 mol ethanol/mole glycerol. PMID:25970750

  6. A continuous process for biodiesel production in a fixed bed reactor packed with cation-exchange resin as heterogeneous catalyst.

    PubMed

    Feng, Yaohui; Zhang, Aiqing; Li, Jianxin; He, Benqiao

    2011-02-01

    Continuous esterification of free fatty acids (FFA) from acidified oil with methanol was carried out with NKC-9 cation-exchange resin in a fixed bed reactor with an internal diameter of 25 mm and a height of 450 mm to produce biodiesel. The results showed that the FFA conversion increased with increases in methanol/oil mass ratio, reaction temperature and catalyst bed height, whereas decreased with increases in initial water content in feedstock and feed flow rate. The FFA conversion kept over 98.0% during 500 h of continuous esterification processes under 2.8:1 methanol to oleic acid mass ratio, 44.0 cm catalyst bed height, 0.62 ml/min feed flow rate and 65°C reaction temperature, showing a much high conversion and operational stability. Furthermore, the loss of sulfonic acid groups from NKC-9 resin into the production was not found during continuous esterification. In sum, NKC-9 resin shows the potential commercial applications to esterification of FFA. PMID:21078550

  7. Simulation of Radioactive Corrosion Product in Primary Cooling System of Japanese Sodium-Cooled Fast Breeder Reactor

    NASA Astrophysics Data System (ADS)

    Matuo, Youichirou; Miyahara, Shinya; Izumi, Yoshinobu

    Radioactive Corrosion Product (CP) is a main cause of personal radiation exposure during maintenance with no breached fuel in fast breeder reactor (FBR) plants. The most important CP is 54Mn and 60Co. In order to establish techniques of radiation dose estimation for radiation workers in radiation-controlled areas of the FBR, the PSYCHE (Program SYstem for Corrosion Hazard Evaluation) code was developed. We add the Particle Model to the conventional PSYCHE analytical model. In this paper, we performed calculation of CP transfer in JOYO using an improved calculation code in which the Particle Model was added to the PSYCHE. The C/E (calculated / experimentally observed) value for CP deposition was improved through use of this improved PSYCHE incorporating the Particle Model. Moreover, among the percentage of total radioactive deposition accounted for by CP in particle form, 54Mn was estimated to constitute approximately 20 % and 60Co approximately 40 % in the cold-leg region. These calculation results are consistent with the measured results for the actual cold-leg piping in the JOYO.

  8. Biohydrogen and Bioethanol Production from Biodiesel-Based Glycerol by Enterobacter aerogenes in a Continuous Stir Tank Reactor

    PubMed Central

    Jitrwung, Rujira; Yargeau, Viviane

    2015-01-01

    Crude glycerol from the biodiesel manufacturing process is being produced in increasing quantities due to the expanding number of biodiesel plants. It has been previously shown that, in batch mode, semi-anaerobic fermentation of crude glycerol by Enterobacter aerogenes can produce biohydrogen and bioethanol simultaneously. The present study demonstrated the possible scaling-up of this process from small batches performed in small bottles to a 3.6-L continuous stir tank reactor (CSTR). Fresh feed rate, liquid recycling, pH, mixing speed, glycerol concentration, and waste recycling were optimized for biohydrogen and bioethanol production. Results confirmed that E. aerogenes uses small amounts of oxygen under semi-anaerobic conditions for growth before using oxygen from decomposable salts, mainly NH4NO3, under anaerobic condition to produce hydrogen and ethanol. The optimal conditions were determined to be 500 rpm, pH 6.4, 18.5 g/L crude glycerol (15 g/L glycerol) and 33% liquid recycling for a fresh feed rate of 0.44 mL/min. Using these optimized conditions, the process ran at a lower media cost than previous studies, was stable after 7 days without further inoculation and resulted in yields of 0.86 mol H2/mol glycerol and 0.75 mol ethanol/mole glycerol. PMID:25970750

  9. A laboratory and pilot plant scaled continuous stirred reactor separator for the production of ethanol from sugars, corn grits/starch or biomass streams

    SciTech Connect

    Dale, M.C.; Lei, S.; Zhou, C.

    1995-11-01

    An improved bio-reactor has been developed to allow the high speed, continuous, low energy conversion of various substrates to ethanol. The Continuous Stirred Reactor Separator (CSRS) incorporates gas stripping of the ethanol using a recalculating gas stream between cascading stirred reactors in series. We have operated a 4 liter lab scale unit, and built and operated a 24,000 liter pilot scale version of the bioreactor. High rates of fermentation are maintained in the reactor stages using a highly flocculant yeast strain. Ethanol is recovered from the stripping gas using a hydrophobic solvent absorber (isothermal), after which the gas is returned to the bioreactor. Ethanol can then be removed from the solvent to recover a highly concentrate ethanol product. We have applied the lab scale CSRS to sugars (glucose/sucrose), molasses, and raw starch with simultaneous saccharification and fermentation of the starch granules (SSF). The pilot scale CCRS has been operated as a cascade reactor using dextrins as a feed. Operating data from both the lab and pilot scale CSRS are presented. Details of how the system might be applied to cellulosics, with some preliminary data are also given.

  10. A laboratory and pilot plant scaled continuous stirred reactor separator for the production of ethanol from sugars, corn grits/starch or biomass streams

    SciTech Connect

    Dale, M.C.; Lei, Shuiwang; Zhou, Chongde

    1995-10-01

    An improved bio-reactor has been developed to allow the high speed, continues, low energy conversion of various substrates to ethanol. The Continuous Stirred Reactor Separator (CSRS) incorporates gas stripping of the ethanol using a recalculating gas stream between cascading stirred reactors in series. We have operated a 4 liter lab scale unit, and built and operated a 24,000 liter pilot scale version of the bioreactor. High rates of fermentation are maintained in the reactor stages using a highly flocculent yeast strain. Ethanol is recovered from the stripping gas using a hydrophobic solvent absorber (isothermal), after which the gas is returned to the bioreactor. Ethanol can then be removed from the solvent to recover a highly concentrated ethanol product. We have applied the lab scale CSRS to sugars (glucose/sucrose), molasses, and raw starch with simultaneous saccharification and fermentation of the starch granules (SSF). The pilot scale CSRS has been operated as a cascade reactor using dextrins as a feed. Operating data from both the lab and pilot scale CSRS are presented. Details of how the system might be applied to cellulosics, with some preliminary data are also given.

  11. Nanocrystalline SiC and Ti3SiC2 Alloys for Reactor Materials: Diffusion of Fission Product Surrogates

    SciTech Connect

    Henager, Charles H.; Jiang, Weilin

    2014-11-01

    MAX phases, such as titanium silicon carbide (Ti3SiC2), have a unique combination of both metallic and ceramic properties, which make them attractive for potential nuclear applications. Ti3SiC2 has been suggested in the literature as a possible fuel cladding material. Prior to the application, it is necessary to investigate diffusivities of fission products in the ternary compound at elevated temperatures. This study attempts to obtain relevant data and make an initial assessment for Ti3SiC2. Ion implantation was used to introduce fission product surrogates (Ag and Cs) and a noble metal (Au) in Ti3SiC2, SiC, and a dual-phase nanocomposite of Ti3SiC2/SiC synthesized at PNNL. Thermal annealing and in-situ Rutherford backscattering spectrometry (RBS) were employed to study the diffusivity of the various implanted species in the materials. In-situ RBS study of Ti3SiC2 implanted with Au ions at various temperatures was also performed. The experimental results indicate that the implanted Ag in SiC is immobile up to the highest temperature (1273 K) applied in this study; in contrast, significant out-diffusion of both Ag and Au in MAX phase Ti3SiC2 occurs during ion implantation at 873 K. Cs in Ti3SiC2 is found to diffuse during post-irradiation annealing at 973 K, and noticeable Cs release from the sample is observed. This study may suggest caution in using Ti3SiC2 as a fuel cladding material for advanced nuclear reactors operating at very high temperatures. Further studies of the related materials are recommended.

  12. Efficient production of methane from artificial garbage waste by a cylindrical bioelectrochemical reactor containing carbon fiber textiles

    PubMed Central

    2013-01-01

    A cylindrical bioelectrochemical reactor (BER) containing carbon fiber textiles (CFT; BER + CFT) has characteristics of bioelectrochemical and packed-bed systems. In this study, utility of a cylindrical BER + CFT for degradation of a garbage slurry and recovery of biogas was investigated by applying 10% dog food slurry. The working electrode potential was electrochemically regulated at −0.8 V (vs. Ag/AgCl). Stable methane production of 9.37 L-CH4 · L−1 · day−1 and dichromate chemical oxygen demand (CODcr) removal of 62.5% were observed, even at a high organic loading rate (OLR) of 89.3 g-CODcr · L−1 · day−1. Given energy as methane (372.6 kJ · L−1 · day−1) was much higher than input electric energy to the working electrode (0.6 kJ · L−1 · day−1) at this OLR. Methanogens were highly retained in CFT by direct attachment to the cathodic working electrodes (52.3%; ratio of methanogens to prokaryotes), compared with the suspended fraction (31.2%), probably contributing to the acceleration of organic material degradation and removal of organic acids. These results provide insight into the application of cylindrical BER + CFT in efficient methane production from garbage waste including a high percentage of solid fraction. PMID:23497472

  13. Continuous production of lactic acid from molasses by perfusion culture of Lactococcus lactis using a stirred ceramic membrane reactor.

    PubMed

    Ohashi, R; Yamamoto, T; Suzuki, T

    1999-01-01

    A perfusion culture system was used for continuous production of lactic acid by retaining cells at a high density of Lactococcus lactis in a stirred ceramic membrane reactor (SCMR). After the cell concentration increased to 248 g/l, half of the culture broth volume was replaced with the fermentation medium. Subsequently, a substrate solution containing glucose (run 1) or molasses (run 2) was continuously supplied to the cells retained in the SCMR. Simultaneously, the culture supernatant was extracted using a ceramic filter with a pore size of 0.2 mum. The dilution rate was initially set at 0.4 h(-1) and gradually decreased to 0.2 h(-1) due to reduction in the permeability of the filter. The concentration of glucose in the substrate solution was adjusted to 60 g/l for the transition and the first period until 240 h, 90 g/l for the second period from 240 h to 440 h, and 70 g/l for the third period from 440 h to 643 h. The average concentration of lactic acid in the filtrate reached 46 g/l in the first period, 43 g/l in the second period, and 33 g/l for the third period. The productivity obtained for the first period reached 15.8 g.l(-1).h(-1), twice as much as that achieved in repeated batch fermentations. Based on the results obtained in run 1, the substrate solution containing 120 g/l of molasses was continuously supplied for 240 h in run 2. The concentration and productivity of lactic acid reached 40 g/l and 10.6 g.l(-1).h(-1), respectively, by continuously replenishing the culture medium at a dilution rate of 0.26 h(-1). These results demonstrated that the filtration capacity of the SCMR was sufficient for a continuous and rapid replenishment of molasses solution from the dense cell culture and, therefore, the perfusion culture system is considered to provide a low-cost process for continuous production of lactic acid from cheap resources. PMID:16232533

  14. Design modification for the modular helium reactor for higher temperature operation and reliability studies for nuclear hydrogen production processes

    NASA Astrophysics Data System (ADS)

    Reza, S. M. Mohsin

    Design options have been evaluated for the Modular Helium Reactor (MHR) for higher temperature operation. An alternative configuration for the MHR coolant inlet flow path is developed to reduce the peak vessel temperature (PVT). The coolant inlet path is shifted from the annular path between reactor core barrel and vessel wall through the permanent side reflector (PSR). The number and dimensions of coolant holes are varied to optimize the pressure drop, the inlet velocity, and the percentage of graphite removed from the PSR to create this inlet path. With the removal of ˜10% of the graphite from PSR the PVT is reduced from 541°C to 421°C. A new design for the graphite block core has been evaluated and optimized to reduce the inlet coolant temperature with the aim of further reduction of PVT. The dimensions and number of fuel rods and coolant holes, and the triangular pitch have been changed and optimized. Different packing fractions for the new core design have been used to conserve the number of fuel particles. Thermal properties for the fuel elements are calculated and incorporated into these analyses. The inlet temperature, mass flow and bypass flow are optimized to limit the peak fuel temperature (PFT) within an acceptable range. Using both of these modifications together, the PVT is reduced to ˜350°C while keeping the outlet temperature at 950°C and maintaining the PFT within acceptable limits. The vessel and fuel temperatures during low pressure conduction cooldown and high pressure conduction cooldown transients are found to be well below the design limits. The reliability and availability studies for coupled nuclear hydrogen production processes based on the sulfur iodine thermochemical process and high temperature electrolysis process have been accomplished. The fault tree models for both these processes are developed. Using information obtained on system configuration, component failure probability, component repair time and system operating modes and conditions, the system reliability and availability are assessed. Required redundancies are made to improve system reliability and to optimize the plant design for economic performance. The failure rates and outage factors of both processes are found to be well below the maximum acceptable range.

  15. Potential role of the Fast Flux Test Facility and the advanced test reactor in the U.S. tritium production system

    SciTech Connect

    Dautel, W.A.

    1996-10-01

    The Deparunent of Energy is currently engaged in a dual-track strategy to develop an accelerator and a conunercial light water reactor (CLWR) as potential sources of tritium supply. New analysis of the production capabilities of the Fast Flux Test Facility (FFTF) at the Hanford Site argues for considering its inclusion in the tritium supply,system. The use of the FFTF (alone or together with the Advanced Test Reactor [ATR] at the Idaho National Engineering Laboratory) as an integral part of,a tritium production system would help (1) ensure supply by 2005, (2) provide additional time to resolve institutional and technical issues associated with the- dual-track strategy, and (3) reduce discounted total life-cycle`costs and near-tenn annual expenditures for accelerator-based systems. The FFRF would also provide a way to get an early start.on dispositioning surplus weapons-usable plutonium as well as provide a source of medical isotopes. Challenges Associated With the Dual-Track Strategy The Departinent`s purchase of either a commercial reactor or reactor irradiation services faces challenging institutional issues associated with converting civilian reactors to defense uses. In addition, while the technical capabilities of the individual components of the accelerator have been proven, the entire system needs to be demonstrated and scaled upward to ensure that the components work toge ther 1548 as a complete production system. These challenges create uncertainty over the ability of the du2a-track strategy to provide an assured tritium supply source by 2005. Because the earliest the accelerator could come on line is 2007, it would have to operate at maximum capacity for the first few years to regenerate the reserves lost through radioactive decay aftei 2005.

  16. Effect of thermal pre-treatment on inoculum sludge to enhance bio-hydrogen production from alkali hydrolysed rice straw in a mesophilic anaerobic baffled reactor.

    PubMed

    El-Bery, Haitham; Tawfik, Ahmed; Kumari, Sheena; Bux, Faizal

    2013-01-01

    The effect of thermal pre-treatment on inoculum sludge for continuous H2 production from alkali hydrolysed rice straw using anaerobic baffled reactor (ABR) was investigated. Two reactors, ABR1 and ABR2, were inoculated with untreated and thermally pre-treated sludge, respectively. Both reactors were operated in parallel at a constant hydraulic retention time of 20 h and organic loading rate ranged from 0.5 to 2.16 g COD/L d. The results obtained indicated that ABR2 achieved a better hydrogen conversion rate and hydrogen yield as compared with ABR1. The hydrogen conversion rates were 30% and 24%, while the hydrogen yields were 1.19 and 0.97 mol H2/mol glucose for ABR2 and ABR1, respectively. Similar trend was observed for chemical oxygen demand (COD) and carbohydrate removal, where ABR2 provided a removal efficiency of 53 +/- 2.3% for COD and 46 +/- 2% for carbohydrate. The microbial community analysis using 16S rRNA phylogeny revealed the presence of different species of bacteria, namely Clostridium, Prevotella, Paludibacter, Ensifer, and Petrimonas within the reactors. Volatile fatty acids generated from ABR1 and ABR2 were mainly in the form of acetate and butyrate and a relatively low fraction ofpropionate was detected in ABR1. Based on these results, thermal pre-treatment ofinoculum sludge is preferable for hydrogen production from hydrolysed rice straw. PMID:24350450

  17. Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

    PubMed

    Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

    2015-01-01

    This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo. PMID:25537991

  18. Enhanced production of poly(3-hydroxybutyrate) in a novel airlift reactor with in situ cell retention using Azohydromonas australica.

    PubMed

    Gahlawat, Geeta; Sengupta, Bedoshree; Srivastava, Ashok K

    2012-09-01

    Economic production of biodegradable plastics is a challenge particularly because of high substrate and energy cost inputs for its production. Research efforts are being directed towards innovations to minimize both of the above costs to economize polyhydroxybutyrate (PHB) production. A novel airlift reactor (ALR) with outer aeration and internal settling was utilized in this investigation. Although it featured no power consumption for agitation, it facilitated increased oxygen transfer rate and better cell retention than stirred tank reactor (STR), thereby resulting in enhanced PHB productivity. ALR with in situ cell retention demonstrated a significant improvement in biomass concentration and biopolymer accumulation. The total PHB production rate, specific biomass, and product yield in the ALR were observed to be 0.84 g/h, 0.43 g/g, and 0.32 g/g, respectively. The studies revealed that the volumetric oxygen mass transfer rate and mixing time for ALR were 0.016 s⁻¹ and 3.73 s, respectively, at 2.0 vvm as compared with corresponding values of 0.005 s⁻¹ and 4.95 s, respectively, in STR. This demonstrated that ALR has better oxygen mass transfer and mixing efficiency than STR. Hence, ALR with cell retention would serve as a better bioreactor design for economic biopolymer production than STR, particularly due to its lower cost of operation and simplicity along with its enhanced oxygen and heat transfer rates. PMID:22760668

  19. Polymer electrolyte membrane fuel cell grade hydrogen production by methanol steam reforming: A comparative multiple reactor modeling study

    NASA Astrophysics Data System (ADS)

    Katiyar, Nisha; Kumar, Shashi; Kumar, Surendra

    2013-12-01

    Analysis of a fuel processor based on methanol steam reforming has been carried out to produce fuel cell grade H2. Six reactor configurations namely FBR1 (fixed bed reactor), MR1 (H2 selective membrane reactor with one reaction tube), MR2 (H2 selective membrane reactor with two reaction tubes), FBR2 (FBR1 + preferential CO oxidation (PROX) reactor), MR3 (MR1 + PROX), and MR4 (MR2 + PROX) are evaluated by simulation to identify the suitable processing scheme. The yield of H2 is significantly affected by H2 selective membrane, residence time, temperature, and pressure conditions at complete methanol conversion. The enhancement in residence time in MR2 by using two identical reaction tubes provides H2 yield of 2.96 with 91.25 mol% recovery at steam/methanol ratio of 1.5, pressure of 2 bar and 560 K temperature. The exit retentate gases from MR2 are further treated in PROX reactor of MR4 to reduce CO concentration to 4.1 ppm to ensure the safe discharge to the environment. The risk of carbon deposition on reforming catalyst is highly reduced in MR4, and MR4 reactor configuration generates 7.4 NL min-1 of CO free H2 from 0.12 mol min-1 of methanol which can provide 470 W PEMFC feedstock requirement. Hence, process scheme in MR4 provides a compact and innovative fuel cell grade H2 generating unit.

  20. Heat production in depth up to 2500m via in situ combustion of methane using a counter-current heat-exchange reactor

    NASA Astrophysics Data System (ADS)

    Schicks, Judith Maria; Spangenberg, Erik; Giese, Ronny; Heeschen, Katja; Priegnitz, Mike; Luzi-Helbing, Manja; Thaler, Jan; Abendroth, Sven; Klump, Jens

    2014-05-01

    In situ combustion is a well-known method used for exploitation of unconventional oil deposits such as heavy oil/bitumen reservoirs where the required heat is produced directly within the oil reservoir by combustion of a small percentage of the oil. A new application of in situ combustion for the production of methane from hydrate-bearing sediments was tested at pilot plant scale within the first phase of the German national gas hydrate project SUGAR. The applied method of in situ combustion was a flameless, catalytic oxidation of CH4 in a counter-current heat-exchange reactor with no direct contact between the catalytic reaction zone and the reservoir. The catalyst permitted a flameless combustion of CH4 with air to CO2 and H2O below the auto-ignition temperature of CH4 in air (868 K) and outside the flammability limits. This led to a double secured application of the reactor. The relatively low reaction temperature allowed the use of cost-effective standard materials for the reactor and prevented NOx formation. Preliminary results were promising and showed that only 15% of the produced CH4 was needed to be catalytically burned to provide enough heat to dissociate the hydrates in the environment and release CH4. The location of the heat source right within the hydrate-bearing sediment is a major advantage for the gas production from natural gas hydrates as the heat is generated where it is needed without loss of energy due to transportation. As part of the second period of the SUGAR project the reactor prototype of the first project phase was developed further to a borehole tool. The dimensions of this counter-current heat-exchange reactor are about 540 cm in length and 9 cm in diameter. It is designed for applications up to depths of 2500 m. A functionality test and a pressure test of the reactor were successfully carried out in October 2013 at the continental deep drilling site (KTB) in Windischeschenbach, Germany, in 600 m depth and 2000 m depth, respectively. In this study we present technical details of the reactor, the catalyst and potential fields of application beside the production of natural gas from hydrate bearing sediments.

  1. Environmental consequences of postulated plutonium releases from Exxon Nuclear MOFP, Richland, Washington, as a result of severe natural phenomena

    SciTech Connect

    Jamison, J.D.; Watson, E.C.

    1980-02-01

    Potential environmental consequences in terms of radiation dose to people are presented for postulated plutonium releases caused by severe natural phenomena at the Exxon Nuclear Company Mixed Oxide Fabrication Plant (MOFP), Richland, Washington. The severe natural phenomena considered are earthquakes, tornadoes, high straight-line winds, and floods. Maximum plutonium deposition values are given for significant locations around the site. All important potential exposure pathways are examined. The most likely 50-year committed dose equivalents are given for the maximum-exposed individual and the population within a 50-mile radius of the plant. The maximum plutonium deposition values most likely to occur offsite are also given.

  2. A low-temperature co-fired ceramic micro-reactor system for high-efficiency on-site hydrogen production

    NASA Astrophysics Data System (ADS)

    Jiang, Bo; Maeder, Thomas; Santis-Alvarez, Alejandro J.; Poulikakos, Dimos; Muralt, Paul

    2015-01-01

    A ceramic-based, meso-scale fuel processor for on-board production of syngas fuel was demonstrated for applications in micro-scale solid-oxide fuel cells (μ-SOFCs). The processor had a total dimension of 12 mm × 40 mm × 2 mm, the gas reforming micro reactor occupying the hot end of a cantilever had outer dimensions of 12 × 18 mm. The device was fabricated through a novel progressive lamination process in low-temperature co-fired ceramic (LTCC) technology. Both, heating function and desired fluidic structures were integrated monolithically into the processor. Using catalytic partial oxidation of a hydrocarbon fuel (propane) as a reaction model, a thermally self-sustaining hydrogen production was achieved. The output flow is sufficiently high to drive an optimized single membrane μSOFC cell of about the same footprint as the micro reactor. Microsystem design, fabrication, catalyst integration as well as the chemical characterization are discussed in detail.

  3. Performance of a novel two-phase continuously fed leach bed reactor for demand-based biogas production from maize silage.

    PubMed

    Linke, Bernd; Rodríguez-Abalde, Ángela; Jost, Carsten; Krieg, Andreas

    2015-02-01

    This study investigated the potential of producing biogas on demand from maize silage using a novel two-phase continuously fed leach bed reactor (LBR) which is connected to an anaerobic filter (AF). Six different feeding patterns, each for 1week, were studied at a weekly average of a volatile solids (VS) loading rate of 4.5 g L(-1) d(-1) and a temperature of 38°C. Methane production from the LBR and AF responded directly proportional to the VS load from the different daily feeding and resulted in an increase up to 50-60% per day, compared to constant feeding each day. The feeding patterns had no impact on VS methane yield which corresponded on average to 330 L kg(-1). In spite of some daily shock loadings, carried out during the different feeding patterns study, the reactor performance was not affected. A robust and reliable biogas production from stalky biomass was demonstrated. PMID:25479391

  4. Ethanol Production from Rice-Straw Hydrolysate Using Zymomonas Mobilis in a Continuous Fluidized-Bed Reactor (FBR)

    SciTech Connect

    deJesus, D.; Nghiem, N.P.

    2001-01-01

    Rice-straw hydrolysate obtained by the Arkenol's concentrated acid hydrolysis process was fermented to ethanol using a recombinant Zymomonas mobilis strain capable of utilizing both glucose and xylose in a continuous fluidized-bed reactor (FBR). The parameters studied included biocatalyst stability with and without antibiotic, feed composition, and retention time. Xylose utilization in the presence of tetracycline remained stable for at least 17 days. This was a significant improvement over the old strain, Z. mobilis CP4 (pZB5), which started to lose xylose utilization capability after seven days. In the absence of tetracycline, the xylose utilization rate started to decrease almost immediately. With tetracycline in the feed for the first six days, stability of xylose utilization was maintained for four days after the antibiotic was removed from the feed. The xylose utilization rate started to decrease on day 11. In the presence of tetracycline using the Arkenol's hydrolysate diluted to 48 g/L glucose and 13 g/L xylose at a retention time of 4.5 h, 95% xylose conversion and complete glucose conversion occurred. The ethanol concentration was 29 g/L, which gave a yield of 0.48 g/g sugar consumed or 94% of the theoretical yield. Using the Arkenol's hydrolysate diluted to 83 g/L glucose and 28 g/L xylose, 92% xylose conversion and complete glucose conversion were obtained. The ethanol concentration was 48 g/L, which gave a yield of 0.45 g/ g sugar consumed or 88% of the theoretical yield. Maximum productivity of 25.5 g/L-h was obtained at a retention time of 1.9 h. In this case, 84% xylose conversion was obtained.

  5. Back propagation neural network modelling of biodegradation and fermentative biohydrogen production using distillery wastewater in a hybrid upflow anaerobic sludge blanket reactor.

    PubMed

    Sridevi, K; Sivaraman, E; Mullai, P

    2014-08-01

    In a hybrid upflow anaerobic sludge blanket (HUASB) reactor, biodegradation in association with biohydrogen production was studied using distillery wastewater as substrate. The experiments were carried out at ambient temperature (34±1°C) and acidophilic pH of 6.5 with constant hydraulic retention time (HRT) of 24h at various organic loading rates (OLRs) (1-10.2kgCODm(-3)d(-1)) in continuous mode. A maximum hydrogen production rate of 1300mLd(-1) was achieved. A back propagation neural network (BPNN) model with network topology of 4-20-1 using Levenberg-Marquardt (LM) algorithm was developed and validated. A total of 231 data points were studied to examine the performance of the HUASB reactor in acclimatisation and operation phase. The statistical qualities of BPNN models were significant due to the high correlation coefficient, R(2), and lower mean absolute error (MAE) between experimental and simulated data. From the results, it was concluded that BPNN modelling could be applied in HUASB reactor for predicting the biodegradation and biohydrogen production using distillery wastewater. PMID:24746339

  6. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, 3rd Quarterly Report

    SciTech Connect

    Mac Donald, Philip Elsworth

    2002-06-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed.

  7. DESIGN OF AN ON-LINE, MULTI-SPECTROMETER FISSION PRODUCT MONITORING SYSTEM (FPMS) TO SUPPORT ADVANCED GAS REACTOR (AGR) FUEL TESTING AND QUALIFICATION IN THE ADVANCED TEST REACTOR

    SciTech Connect

    J. K. Hartwell; D. M. Scates; M. W. Drigert

    2005-11-01

    The US Department of Energy (DOE) is embarking on a series of tests of coated-particle reactor fuel for the Advanced Gas Reactor (AGR). As one part of this fuel development program a series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). The first test in this series (AGR-1) will incorporate six separate “capsules” irradiated simultaneously, each containing about 51,000 TRISO-coated fuel particles supported in a graphite matrix and continuously swept with inert gas during irradiation. The effluent gas from each of the six capsules must be independently monitored in near real time and the activity of various fission gas nuclides determined and reported. A set of seven heavily-shielded high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based total radiation detectors have been designed, and are being configured and tested for use during the AGR-1 experiment. The AGR-1 test specification requires that the AGR-1 fission product measurement system (FPMS) have sufficient sensitivity to detect the failure of a single coated fuel particle and sufficient range to allow it to “count” multiple (up to 250) successive particle failures. This paper describes the design and expected performance of the AGR-1 FPMS.

  8. Production of medical radioisotopes in the ORNL high flux isotope reactor (HFIR) for cancer treatment and arterial restenosis therapy after PICA

    NASA Astrophysics Data System (ADS)

    Knapp, F. F.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1999-01-01

    The High Flux Isotope Reactor ( HFIR) at the Oak Ridge National Laboratory ( ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. First beginning operation in 1965, the high thermal neutron flux (2.5×1015 neutrons/cm2/sec at 85 MW) and versatile target irradiation and handling facilities provide the opportunity for production of a wide variety of neutron-rich medical radioisotopes of current interest for therapy. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117 m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube ( HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle (22-24 days) and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions ( PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117 m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  9. Production of medical radioisotopes in the ORNL high flux isotope reactor (HFIR) for cancer treatment and arterial restenosis therapy after PICA

    NASA Astrophysics Data System (ADS)

    Knapp, F. F.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1999-01-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. First beginning operation in 1965, the high thermal neutron flux (2.5×1015 neutrons/cm2/sec at 85 MW) and versatile target irradiation and handling facilities provide the opportunity for production of a wide variety of neutron-rich medical radioisotopes of current interest for therapy. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle (22 24 days) and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  10. Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production.

    PubMed

    Barros, Aruana Rocha; Adorno, Maria Angela Tallarico; Sakamoto, Isabel Kimiko; Maintinguer, Sandra Imaculada; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

    2011-02-01

    This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30°C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8h. The reactor R1 operating with a HRT of 2h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2)mol(-1) glucose with 1.3mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter. PMID:21185176

  11. The influence of preculture on the process performance of penicillin V production in a 100-l air-lift tower loop reactor.

    PubMed

    Möller, J; Niehoff, J; Hotop, S; Dors, M; Schügerl, K

    1992-05-01

    The influence of stirrer speed in the third preculture on the performance of penicillin V production by Penicillium chrysogenum in complex medium in a 100-l air-lift tower loop reactor was investigated. The process performance in the main culture was improved by increasing the stirrer speed from 500 to 750 rpm: the pellet size was reduced to half, the cell growth was influenced only slightly, but the production phase was extended considerably, and the final penicillin concentration was increased from 5.1 g l-1 to 10.4 g l-1. PMID:1368239

  12. Design and Nuclear-Safety Related Simulations of Bare-Pellet Test Irradiations for the Production of Pu-238 in the High Flux Isotope Reactor using COMSOL

    SciTech Connect

    Freels, James D; Jain, Prashant K; Hobbs, Randy W

    2012-01-01

    The Oak Ridge National Laboratory (ORNL)is developing technology to produce plutonium-238 for the National Aeronautics and Space Administration (NASA) as a power source material for powering vehicles while in deep-space[1]. The High Flux Isotope Reactor (HFIR) of ORNL has been utilized to perform test irradiations of incapsulated neptunium oxide (NpO2) and aluminum powder bare pellets for purposes of understanding the performance of the pellets during irradiation[2]. Post irradiation examinations (PIE) are currently underway to assess the effect of temperature, thermal expansion, swelling due to gas production, fission products, and other phenomena

  13. Thermal-Hydraulic Analyses of Heat Transfer Fluid Requirements and Characteristics for Coupling A Hydrogen Production Plant to a High-Temperature Nuclear Reactor

    SciTech Connect

    C. B. Davis; C. H. Oh; R. B. Barner; D. F. Wilson

    2005-06-01

    The Department of Energy is investigating the use of high-temperature nuclear reactors to produce hydrogen using either thermochemical cycles or high-temperature electrolysis. Although the hydrogen production processes are in an early stage of development, coupling either of these processes to the hightemperature reactor requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear power plant. An intermediate heat transport loop will be required to separate the operations and safety functions of the nuclear and hydrogen plants. A next generation high-temperature reactor could be envisioned as a single-purpose facility that produces hydrogen or a dual-purpose facility that produces hydrogen and electricity. Early plants, such as the proposed Next Generation Nuclear Plant, may be dual-purpose facilities that demonstrate both hydrogen and efficient electrical generation. Later plants could be single-purpose facilities. At this stage of development, both single- and dual-purpose facilities need to be understood. Seven possible configurations for a system that transfers heat between the nuclear reactor and the hydrogen and/or electrical generation plants were identified. These configurations included both direct and indirect cycles for the production of electricity. Both helium and liquid salts were considered as the working fluid in the intermediate heat transport loop. Methods were developed to perform thermalhydraulic and cycle-efficiency evaluations of the different configurations and coolants. The thermalhydraulic evaluations estimated the sizes of various components in the intermediate heat transport loop for the different configurations. The relative sizes of components provide a relative indication of the capital cost associated with the various configurations. Estimates of the overall cycle efficiency of the various configurations were also determined. The evaluations determined which configurations and coolants are the most promising from thermal-hydraulic and efficiency points of view. These evaluations also determined which configurations and options do not appear to be feasible at the current time.

  14. In situ response of bay productivity to nutrient loading from a small tributary: The Delaware Bay-Murderkill Estuary tidally-coupled biogeochemical reactor

    NASA Astrophysics Data System (ADS)

    Voynova, Yoana G.; Lebaron, Karine C.; Barnes, Rebecca T.; Ullman, William J.

    2015-07-01

    A small, turbid and nutrient-rich tributary, the Murderkill Estuary, and a large estuarine ecosystem, the Delaware Bay, are tightly linked and form an efficient, tidally-coupled biogeochemical reactor during the summer. Nitrate loading from the Murderkill Estuary generates an instantaneous increase in biological oxygen production in the adjacent Delaware Bay. We are able to capture this primary production response with continuous hourly measurements of dissolved oxygen, chlorophyll, and nitrate. The nitrate influxes from the Murderkill support primary production rates in the Delaware Bay margins that are twice as high as the average production rates measured in the central Bay regions. This elevates chlorophyll in the Bay margins in the summer and fuels metabolism. Tidal transport of the newly produced autochthonous chlorophyll particles from the Bay into the Estuary could also provide a source of labile material to the marshes surrounding the Murderkill, thus perhaps fueling marsh respiration. As a consequence of the tidal coupling between Delaware Bay and the Murderkill Estuary, ecosystem productivity and metabolism in the Bay and Estuary are linked, generating an ecosystem feedback mechanism. Storms modulate this tidally-coupled biogeochemical reactor, by generating significant nitrate and salinity changes. Depending on their magnitude and duration, storms induce large phytoplankton blooms in the Delaware Bay. Such large phytoplankton blooms may occur more often with climate change, since century-long discharge records document an increase in storm frequency.

  15. High organic loading rate on thermophilic hydrogen production and metagenomic study at an anaerobic packed-bed reactor treating a residual liquid stream of a Brazilian biorefinery.

    PubMed

    Ferraz Júnior, Antônio Djalma Nunes; Etchebehere, Claudia; Zaiat, Marcelo

    2015-06-01

    This study evaluated the influence of a high organic loading rate (OLR) on thermophilic hydrogen production at an up-flow anaerobic packed-bed reactor (APBR) treating a residual liquid stream of a Brazilian biorefinery. The APBR, filled with low-density polyethylene, was operated at an OLR of 84.2 kg-COD m(-3) d(-1). This value was determined in a previous study. The maximum values of hydrogen production and yield were 5,252.6 mL-H2 d(-1) and 3.7 mol-H2 mol(-1)(total carbohydrates), respectively. However, whereas the OLR remained constant, the specific organic load rate (sOLR) decreased throughout operation from 1.38 to 0.72 g-Total carbohydratesg-VS(-1) h(-1), this decrease negatively affected hydrogen production. A sOLR of 0.98 g-Total carbohydratesg-VS(-1) h(-1) was optimal for hydrogen production. The microbial community was studied using 454-pyrosequencing analysis. Organisms belonging to the genera Caloramator, Clostridium, Megasphaera, Oxobacter, Thermoanaerobacterium, and Thermohydrogenium were detected in samples taken from the reactor at operation days 30 and 60, suggesting that these organisms contribute to hydrogen production. PMID:25812810

  16. Robust Low-Cost Water-Gas Shift Membrane Reactor for High-Purity Hydrogen Production form Coal-Derived Syngas

    SciTech Connect

    James Torkelson; Neng Ye; Zhijiang Li; Decio Coutinho; Mark Fokema

    2008-05-31

    This report details work performed in an effort to develop a low-cost, robust water gas shift membrane reactor to convert coal-derived syngas into high purity hydrogen. A sulfur- and halide-tolerant water gas shift catalyst and a sulfur-tolerant dense metallic hydrogen-permeable membrane were developed. The materials were integrated into a water gas shift membrane reactor in order to demonstrate the production of >99.97% pure hydrogen from a simulated coal-derived syngas stream containing 2000 ppm hydrogen sulfide. The objectives of the program were to (1) develop a contaminant-tolerant water gas shift catalyst that is able to achieve equilibrium carbon monoxide conversion at high space velocity and low steam to carbon monoxide ratio, (2) develop a contaminant-tolerant hydrogen-permeable membrane with a higher permeability than palladium, (3) demonstrate 1 L/h purified hydrogen production from coal-derived syngas in an integrated catalytic membrane reactor, and (4) conduct a cost analysis of the developed technology.

  17. Comparision of real waste (MSW and MPW) pyrolysis in batch reactor over different catalysts. Part I: product yields, gas and pyrolysis oil properties.

    PubMed

    Ateş, Funda; Miskolczi, Norbert; Borsodi, Nikolett

    2013-04-01

    Pyrolysis of municipal solid waste (MSW) and municipal plastic waste (MPW) have been investigated in batch reactor at 500, 550 and 600°C both in absence and presence of catalysts (Y-zeolite, β-zeolite, equilibrium FCC, MoO3, Ni-Mo-catalyst, HZSM-5 and Al(OH)3). The effect of the parameters on the product properties was investigated. Products were characterized using gas-chromatography, GC/MS, (13)C NMR. Yields of volatile fractions increased, while reaction time necessity for the total cracking decreased in the presence of catalysts. Catalysts have productivity and selectivity in converting aliphatic hydrocarbons to aromatic and cyclic compounds in oil products. Gases from MSW consisted of hydrogen CO, CO2, while exclusively hydrogen and hydrocarbons were detected from MPW. Catalyst efficiency was higher using MPW than MSW. Pyrolysis oils contained aliphatic hydrocarbons, aromatics, cyclic compounds and less ketones, alcohols, acids or esters depending on the raw materials. PMID:23455219

  18. Thermodynamic Analysis of the Use a Chemical Heat Pump to Link a Supercritical Water-Cooled Nuclear Reactor and a Thermochemical Water-Splitting Cycle for Hydrogen Production

    NASA Astrophysics Data System (ADS)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.; Pioro, Igor

    Increases in the power generation efficiency of nuclear power plants (NPPs) are mainly limited by the permissible temperatures in nuclear reactors and the corresponding temperatures and pressures of the coolants in reactors. Coolant parameters are limited by the corrosion rates of materials and nuclear-reactor safety constraints. The advanced construction materials for the next generation of CANDU reactors, which employ supercritical water (SCW) as a coolant and heat carrier, permit improved “steam” parameters (outlet temperatures up to 625°C and pressures of about 25 MPa). An increase in the temperature of steam allows it to be utilized in thermochemical water splitting cycles to produce hydrogen. These methods are considered by many to be among the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require an intensive heat supply at temperatures higher than 550-600°C. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump, which increases the temperature of the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. Here, a high-temperature chemical heat pump, which employs the reversible catalytic methane conversion reaction, is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with the second steam cycle of a SCW nuclear power generation plant on one side and a thermochemical water splitting cycle on the other, increases the temperature of the “nuclear” heat and, consequently, the intensity of heat transfer into the water splitting cycle. A comparative preliminary thermodynamic analysis is conducted of the combined system comprising a SCW nuclear power generation plant and a chemical heat pump, which provides high-temperature heat to a thermochemical water splitting cycle for hydrogen production. It is concluded that the proposed chemical heat pump permits the utilization efficiency of nuclear energy to be improved by at least 2% without jeopardizing nuclear reactor safety. Based on this analysis, further research appears to be merited on the proposed advanced design of a nuclear power generation plant combined with a chemical heat pump, and implementation in appropriate applications seems worthwhile.

  19. Microchannel Reactor System Design & Demonstration For On-Site H2O2 Production by Controlled H2/O2 Reaction

    SciTech Connect

    Adeniyi Lawal

    2008-12-09

    We successfully demonstrated an innovative hydrogen peroxide (H2O2) production concept which involved the development of flame- and explosion-resistant microchannel reactor system for energy efficient, cost-saving, on-site H2O2 production. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for controlled direct combination of H2 and O2 in all proportions including explosive regime, at a low pressure and a low temperature to produce about 1.5 wt% H2O2 as proposed. In the second phase of the program, as a prelude to full-scale commercialization, we demonstrated our H2O2 production approach by ‘numbering up’ the channels in a multi-channel microreactor-based pilot plant to produce 1 kg/h of H2O2 at 1.5 wt% as demanded by end-users of the developed technology. To our knowledge, we are the first group to accomplish this significant milestone. We identified the reaction pathways that comprise the process, and implemented rigorous mechanistic kinetic studies to obtain the kinetics of the three main dominant reactions. We are not aware of any such comprehensive kinetic studies for the direct combination process, either in a microreactor or any other reactor system. We showed that the mass transfer parameter in our microreactor system is several orders of magnitude higher than what obtains in the macroreactor, attesting to the superior performance of microreactor. A one-dimensional reactor model incorporating the kinetics information enabled us to clarify certain important aspects of the chemistry of the direct combination process as detailed in section 5 of this report. Also, through mathematical modeling and simulation using sophisticated and robust commercial software packages, we were able to elucidate the hydrodynamics of the complex multiphase flows that take place in the microchannel. In conjunction with the kinetics information, we were able to validate the experimental data. If fully implemented across the whole industry as a result of our technology demonstration, our production concept is expected to save >5 trillion Btu/year of steam usage and >3 trillion Btu/year in electric power consumption. Our analysis also indicates >50 % reduction in waste disposal cost and ~10% reduction in feedstock energy. These savings translate to ~30% reduction in overall production and transportation costs for the $1B annual H2O2 market.

  20. A spectroscopic study of ethylene destruction and by-product generation using a three-stage atmospheric packed-bed plasma reactor

    SciTech Connect

    Huebner, M.; Roepcke, J.; Guaitella, O.; Rousseau, A.

    2013-07-21

    Using a three-stage dielectric packed-bed plasma reactor at atmospheric pressure, the destruction of ethylene, a typical volatile organic compound, and the generation of major by-products have been studied by means of Fourier Transform Infrared Spectroscopy. A test gas mixture air at a gas flow of 1 slm containing 0.12% humidity with 0.1% ethylene has been used. In addition to the fragmentation of the precursor gas, the evolution of the concentration of ten stable reaction products, CO, CO{sub 2}, O{sub 3}, NO{sub 2}, N{sub 2}O, HCN, H{sub 2}O, HNO{sub 3}, CH{sub 2}O, and CH{sub 2}O{sub 2} has been monitored. The concentrations of the by-products range between 5 ppm, in the case of NO{sub 2}, and 1200 ppm, for H{sub 2}O. By the application of three sequentially working discharge cells at a frequency of f = 4 kHz and voltage values between 9 and 12 kV, a nearly complete decomposition of C{sub 2}H{sub 4} could be achieved. Furthermore, the influence of the specific energy deposition (SED) on the destruction process has been studied and the maximum value of SED was about 900 J l{sup -1}. The value of the characteristic energy {beta}, characterizing the energy efficiency of the ethylene destruction in the reactor, was found to be 330 J l{sup -1}. It was proven that the application of three reactor stages suppresses essentially the production of harmful by-products as formaldehyde, formic acid, and NO{sub 2} compared to the use of only one or two stages. Based on the multi-component detection, the carbon balance of the plasma chemical conversion of ethylene has been analyzed. The dependence of the fragmentation efficiencies of ethylene (R{sub F}(C{sub 2}H{sub 4}) = 5.5 Multiplication-Sign 10{sup 19} molecules J{sup -1}) and conversion efficiencies to the produced molecular species (R{sub C} = (0.1-3) Multiplication-Sign 10{sup 16} molecules J{sup -1}) on the discharge conditions could be estimated in the multistage plasma reactor.

  1. Hydrogen production enhancement and the effect of passive mixing using flow disturbers in a steam-reforming reactor

    NASA Astrophysics Data System (ADS)

    Liao, Chang-Hsien

    This study investigates the influence of changing the flow pathway inside a methanol steam reformer by introduction of flow disturbers in the flow field. In a reforming reaction, it is known that fuel conversion from hydrocarbons to hydrogen can be limited by chemical kinetics, which is a function of local temperature. For a typical cylindrical reactor, large thermal gradients inside the packed bed result from insufficient heat and mass transfer. This causes a non-ideal condition for complete conversion to hydrogen. Active mixing methods in critical fluid pathways have been proven to improve heat and mass transfer inside reforming reactors. A new method of passive mixing in the fluid pathways by introducing flow disturbers inside the packed catalyst bed is presented. A principle of characteristic time of a 1st order reaction is also presented and studied. The reactor output parameters of fuel conversion, temperature profile, characteristic time, pressure drop, reactor efficiency, and power demand are analyzed and compared to quantify the influence of the passive mixing technique. Input variables in this study are packing density of flow disturbers, space velocity and catalyst size. This study is expected to provide a basic analysis and contribute to the improvement of reformer design for better fuel processing system performance.

  2. Large-scale production of saikosaponins through root culturing of Bupleurum falcatum L. using modified airlift reactors.

    PubMed

    Kusakari, Ken; Yokoyama, Mineyuki; Inomata, Shinji; Gozu, Yoko; Katagiri, Chika; Sugimoto, Yukihiro

    2012-01-01

    Modification of internal configuration of a bubble column, airlift and stirred tank reactor (10-200 L) was made for root cultures of Bupleurum falcatum L. Agitation with an impeller covered with partition mesh was ineffective for a 10-L modified reactor, because it caused intensive foaming and subsequent overflow of the culture medium even at a low rotation speed of 50 rpm and a low aeration rate of 0.1 vvm (volume per volume of medium). In contrast, efficient aeration through a ceramic sparger placed at the bottom of a 20-L bubble column reactor yielded approximately 25 g/L of dry roots and 500 mg/L of saikosaponin-a and saikosaponin-d over 42 days. On a 200-L scale, however, the roots became flocculated under the upper perforated plate initially positioned near the middle of the reactor, forming a firm disk of roots and a large empty space between the disk and the medium. Thus, the roots had poor contact with the medium, which severely suppressed their growth. To avoid this flocculation, a bottom perforated plate and draft tube were installed as a partitioning device separating the culturing area (outside the draft tube) from the aeration area (inside the draft tube). The draft tube was made of a stainless steel mesh rather than a solid material, and the tube greatly increased the root yield in the 20-L reactor. This configuration was successfully applied at the 200-L scale, yielding 500-600 mg/L of saikosaponin-a and saikosaponin-d over 56 days. PMID:21940203

  3. Environmental assessment for Trench 33 widening in 218-W-5 Low-Level Burial Ground, Hanford Site, Richland, Washington

    SciTech Connect

    1997-07-01

    This environmental assessment (EA) has been prepared to assess potential environmental impacts associated with the US Department of Energy`s proposed action: to widen and operated the unused Trench 33 in the 218-W-5 Low-Level Burial Ground. Information contained herein will be used by the US Department of Energy, Richland Operations Office Manager, to determine if the Proposed Action is a major federal action significantly affecting the quality of the human environment. If the Proposed Action is determined to be major and significant, an environmental impact statement will be prepared. If the Proposed Action is determined not to be major and significant, a Finding of No significant Impact will be issued and the action may proceed.

  4. Public health assessment for Palmetto Recycling, Incorporated, Columbia, Richland County, South Carolina, Region 4. Cerclis No. SCD037398120

    SciTech Connect

    1995-09-07

    The Palmetto Recycling Incorporated (PRI) site consists of 1.5 acres of land on Koon Store Road, in a rural area approximately 8 miles north of Columbia in Richland County, South Carolina. The main sources of contamination appear to come from liquids and sludges generated as a result of a lead reclamation operations. Contaminants of concern were identified in on-site soils, surface water, groundwater and in off-site soil, groundwater, surface water, and sediments. Contaminants of concern include: arsenic, iron, manganese, and lead. The PRI site is classified as a public health hazard. This classification is based on the fact that the available data indicate humans may be exposed to substances in on-site and off-site soil that, after long-term exposures, can cause adverse health effects.

  5. A fuzzy-logic-based model to predict biogas and methane production rates in a pilot-scale mesophilic UASB reactor treating molasses wastewater.

    PubMed

    Turkdogan-Aydinol, F Ilter; Yetilmezsoy, Kaan

    2010-10-15

    A MIMO (multiple inputs and multiple outputs) fuzzy-logic-based model was developed to predict biogas and methane production rates in a pilot-scale 90-L mesophilic up-flow anaerobic sludge blanket (UASB) reactor treating molasses wastewater. Five input variables such as volumetric organic loading rate (OLR), volumetric total chemical oxygen demand (TCOD) removal rate (R(V)), influent alkalinity, influent pH and effluent pH were fuzzified by the use of an artificial intelligence-based approach. Trapezoidal membership functions with eight levels were conducted for the fuzzy subsets, and a Mamdani-type fuzzy inference system was used to implement a total of 134 rules in the IF-THEN format. The product (prod) and the centre of gravity (COG, centroid) methods were employed as the inference operator and defuzzification methods, respectively. Fuzzy-logic predicted results were compared with the outputs of two exponential non-linear regression models derived in this study. The UASB reactor showed a remarkable performance on the treatment of molasses wastewater, with an average TCOD removal efficiency of 93 (+/-3)% and an average volumetric TCOD removal rate of 6.87 (+/-3.93) kg TCOD(removed)/m(3)-day, respectively. Findings of this study clearly indicated that, compared to non-linear regression models, the proposed MIMO fuzzy-logic-based model produced smaller deviations and exhibited a superior predictive performance on forecasting of both biogas and methane production rates with satisfactory determination coefficients over 0.98. PMID:20609515

  6. Experimental Determination of the Spent Graphite Radioactive Contamination at Plutonium-Production Reactors of the Siberian Group of Chemical Enterprises (TOMSK-7)

    SciTech Connect

    Bushuev, Anatoly Y.; Verzilov, Yury M.; Zubarev, Viktor N.; Kachanovsky, Alexander E.; Proshin, Igor M.; Petrova, Ekaterina V.; Aleeva, Tatiana B.; Dmitriev, Alexander M.; Zakharova, Elena V.; Ushakov, Sergei I.; Nikolaev, Andrey G.; Baranov, Igor I.; Kabanov, Yury I.

    2002-10-15

    Spent graphite from decommissioned plutonium-production uranium-graphite reactors is contaminated with radionuclides, and this graphite represents an important fraction of the radioactive wastes accumulated by the Russian nuclear power industry. To select proper ways and dates for the management of graphite, the information regarding the composition and level of the graphite contamination is required.In the paper, results are presented that were obtained in studies carried out at the I-1, EI-2, and ADE-3 reactors of the Siberian Group of Chemical Enterprises (Russia) in 1996-1999. The main feature of the studies is a wide-scale sampling from the graphite piles of the aforementioned reactors followed by complex assays of their radioactive contamination.The analyses performed for the large number of graphite samples made it possible to obtain a detailed picture of the pile contamination, to study radionuclide distributions over the piles, to construct schemes for evaluation of radionuclide stockpiles, and to evaluate stockpiles of several radionuclides including {sup 14}C, {sup 3}H, {sup 90}Sr, {sup 241}Am, {sup 244}Cm, {sup 238,239,240,241}Pu, {sup 137,134}Cs, and {sup 60}Co.

  7. Influence of organic loading rate on the anaerobic treatment of sugarcane vinasse and biogás production in fluidized bed reactor.

    PubMed

    Siqueira, Laura M; Damiano, Elisabeth S G; Silva, Edson L

    2013-01-01

    This study evaluated an anaerobic fluidized bed reactor (AFBR) that contained polystyrene particles as a support material for the treatment of vinasse that resulted from the alcoholic fermentation of sugarcane molasses. The AFBR was inoculated with sludge from an upflow anaerobic sludge blanket reactor that treated poultry slaughterhouse wastewater. The AFBR was operated with a hydraulic retention time of 24 h at a temperature of 30°C with influent vinasse concentrations that ranged from 2273 to 20,073 mg COD L(-1). The reactor was subjected to increased organic loading rates (OLR) that ranged from 3.33 to 26.19 kg COD m(-3) d(-1), with COD removal efficiencies that ranged from 51% to 70% and maximum removal at an OLR of 13.93 ± 2.18 kg COD m(-3) d(-1). The maximum biogas productivity was 5.37 m(3) CH4 m(-3) d(-1) for an OLR of 25.32 kg COD m(-3) d(-1) (average removal of 51%).. PMID:23947710

  8. Fast-Mixed Spectrum Reactor progress report. Results of the FMSR Benchmark calculations and an assessment of current fission product libraries

    SciTech Connect

    Ludewig, H.; Durston, C.; Atefi, B.; Cerbone, R.J.

    1980-06-01

    As part of the Initial Feasibility Study of the Fast Mixed Spectrum Reactor, a series of benchmark calculations were made to determine the sensitivity of the physics analysis to differences in methods and data. Argonne National Laboratory (ANL), the Massachusetts Institute of Technology (MIT), and Oak Ridge National Laboratory (ORNL) were invited to participate with Brookhaven National Laboratory in the analysis of a FMSR model prescribed by BNL. Detailed comparisons are made including a comprehensive study on the adequacy of the fission product treatments.

  9. Hybrid reactors. [Fuel cycle

    SciTech Connect

    Moir, R.W.

    1980-09-09

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

  10. Growth of InGaAlP HB-LEDs in a large-scale-production reactor

    NASA Astrophysics Data System (ADS)

    Li, Sherman; Collins, D. A.; Vatanapradit, S.; Ferreira, M.; Zawadzki, Peter A.; Stall, Richard A.; Eliashevich, Ivan; Nering, J. E.

    1999-04-01

    The theory, structure, and current manufacturing technologies for InGaAlP high brightness light emitting diodes (HB-LED) emitting in the range of 650 to 585 nm are described in this paper. A state-of-the-art HB-LED MOCVD reactor designed for high volume manufacturing (42 - 2' or 16 - 3' wafers) is demonstrated. Data for thickness and compositional uniformity and reproducibility are presented showing the material quality and reactor stability that can currently be achieved. In addition, device data for InGaAlP HB-LEDs is reported, including brightness, forward voltage, and emission wavelength with excellent intra and inter wafer uniformity and run-to-run reproducibility.

  11. Design of a single chambered microbial electrolytic cell reactor for production of biohydrogen from rice straw hydrolysate.

    PubMed

    Gupta, Pratima; Parkhey, Piyush

    2015-06-01

    Rice straw was pretreated using a microwave-assisted alkali pretreatment method. Cellulose recovery was approximately 82 %. This material was hydrolysed in an optimized enzymatic saccharification reaction using cellulase from Lysinibacillus sphaericus. This resulted in saccharification of 49 % of cellulosic biomass into glucose. A single chambered microbial electrolytic cell reactor of volume 2l was built using acrylic plastic sheets with graphite sheet as anode and a stainless-steel mesh as cathode. Shewanella putrefaciens was used as exoelectrogen to oxidize rice straw hydrolysate in the reactor for electrohydrogenesis. The maximum H2 yield obtained was 801 ml H2 g(-1) COD removal. Coulombic efficiency of 88 %, cathodic H2 recovery of 58 % and total H2 recovery of 51 % with an energy efficiency of 74 % were recorded. PMID:25650347

  12. REACTOR FUEL SCAVENGING MEANS

    DOEpatents

    Coffinberry, A.S.

    1962-04-10

    A process for removing fission products from reactor liquid fuel without interfering with the reactor's normal operation or causing a significant change in its fuel composition is described. The process consists of mixing a liquid scavenger alloy composed of about 44 at.% plutoniunm, 33 at.% lanthanum, and 23 at.% nickel or cobalt with a plutonium alloy reactor fuel containing about 3 at.% lanthanum; removing a portion of the fuel and scavenger alloy from the reactor core and replacing it with an equal amount of the fresh scavenger alloy; transferring the portion to a quiescent zone where the scavenger and the plutonium fuel form two distinct liquid layers with the fission products being dissolved in the lanthanum-rich scavenger layer; and the clean plutonium-rich fuel layer being returned to the reactor core. (AEC)

  13. Solvent refined coal reactor quench system

    DOEpatents

    Thorogood, Robert M.

    1983-01-01

    There is described an improved SRC reactor quench system using a condensed product which is recycled to the reactor and provides cooling by evaporation. In the process, the second and subsequent reactors of a series of reactors are cooled by the addition of a light oil fraction which provides cooling by evaporation in the reactor. The vaporized quench liquid is recondensed from the reactor outlet vapor stream.

  14. Solvent refined coal reactor quench system

    DOEpatents

    Thorogood, R.M.

    1983-11-08

    There is described an improved SRC reactor quench system using a condensed product which is recycled to the reactor and provides cooling by evaporation. In the process, the second and subsequent reactors of a series of reactors are cooled by the addition of a light oil fraction which provides cooling by evaporation in the reactor. The vaporized quench liquid is recondensed from the reactor outlet vapor stream. 1 fig.

  15. Retrofit Russian research reactors

    SciTech Connect

    Mabe, W.

    1993-04-01

    A likely source for enriched uranium for production of a gun-type bomb might be a research reactor. A state or terrorist organization would find the technical process for separating uranium from the reactor fuel plates is simple and well-published. An unguarded research reactor could be found in the former Soviet Union. Russia and the former republics have seen an increasing number of terrorist incidents, including hijackings and bombings. Recognizing the danger, Russia and the U.S. have explored means of safeguarding former Soviet weapons materials. This article describes some of the plans to reduce the risk of nuclear materials being obtained for illicit weapons production.

  16. Biohydrogen production from chemical wastewater treatment in biofilm configured reactor operated in periodic discontinuous batch mode by selectively enriched anaerobic mixed consortia.

    PubMed

    Venkata Mohan, S; Vijaya Bhaskar, Y; Sarma, P N

    2007-06-01

    Molecular hydrogen (H(2)) production with simultaneous wastewater treatment was studied in biofilm configured periodic discontinuous/sequencing batch reactor using chemical wastewater as substrate. Anaerobic mixed consortia was sequentially pretreated with repeated heat-shock (100 degrees C; 2 h) and acid (pH-3.0; 24 h) treatment procedures to selectively enrich the H(2) producing mixed consortia prior to inoculation of the reactor. The bioreactor was operated at mesophilic (room) temperature (28+/-2 degrees C) under acidophilic conditions with a total cycle period of 24 h consisting of FILL (15 min), REACT (23 h), SETTLE (30 min) and DECANT (15 min) phases. Reactor was initially operated with synthetic wastewater (SW) at OLR of 4.8 kg COD/m(3)-day and subsequently operated using composite chemical wastewater (CW) at OLR of 5.6 kg COD/m(3)-day by adjusting pH to 6.0 prior to feeding to inhibit the methanogenic activity. H(2) evolution rate differed significantly with the nature of wastewater used as substrate [SW--volumetric H(2) production rate--12.89 mmol H(2)/m(3)-min and specific H(2) production rate--0.0084 mmol H(2)/min-g COD(L) (0.026 mmol H(2)/min-g COD(R)); CW--volumetric H(2) production rate--6.076 mmol H(2)/m(3)-min and specific H(2) production rate--0.0089 mmol H(2)/min-g COD(L) (0.033 mmol H(2)/min-g COD(R))]. Relatively rapid progress towards higher H(2) yield (2 h) was observed with SW compared to the CW (10 h). Substrate (COD) reduction of 32.4% (substrate degradation rate (SDR)--1.55 kg COD/m(3)-day) and 26.7% (SDR-1.49 kg COD/m(3)-day) was observed with SW and CW, respectively. The system showed rapid stabilization tendency (SW--37 days; CW--40 days) with respect to H(2) generation and COD reduction. H(2) evolution showed relatively good correlation with VFA concentration in the case of SW (R(2)-0.961) compared to CW (R(2)-0.912). A surge in pH values from 5.87 to 4.23 (SW) and 5.93 to 4.62 (CW) was observed during the cycle operation. Integration of biofilm configuration with periodic discontinuous batch operation under the defined operating conditions showed potential to influence the microbial system by selectively enriching the specific group of microflora capable of producing H(2). PMID:17418367

  17. Study on product distributions and char morphology during rapid co-pyrolysis of platanus wood and lignite in a drop tube fixed-bed reactor.

    PubMed

    Meng, Haiyu; Wang, Shuzhong; Chen, Lin; Wu, Zhiqiang; Zhao, Jun

    2016-06-01

    The rapid co-pyrolytic behavior of platanus wood and Pingzhuang lignite was explored in a drop tube fixed-bed reactor under nitrogen atmosphere. Synergistic effects were evaluated using the deviations between experimental and predicted values of product yields and gas components. Surface morphology of residual chars were also investigated applying the scanning electron microscopy technique (SEM). This study found that the experimental values of gas volume yields were greater than the predicted, and the maximum gas volume yield exhibited with 50% biomass blending ratio at 1000°C. Positive or negative synergistic effects happened in gas components at different blending ratios and temperatures. The SEM results indicated that the differences of char surface morphology were evident. The fractal dimensions of residual chars increased with increasing biomass blending ratio, which may improve their gasification or combustion reactivity. The change in product yields and gas components was attributed to the secondary reactions and tar cracking. PMID:26985627

  18. Development of Tritium Permeation Analysis Code and Tritium Transport in a High Temperature Gas-Cooled Reactor Coupled with Hydrogen Production System

    SciTech Connect

    Chang H. Oh; Eung S. Kim; Mike Patterson

    2010-06-01

    Abstract – A tritium permeation analyses code (TPAC) was developed by Idaho National Laboratory for the purpose of analyzing tritium distributions in very high temperature reactor (VHTR) systems, including integrated hydrogen production systems. A MATLAB SIMULINK software package was used in developing the code. The TPAC is based on the mass balance equations of tritium-containing species and various forms of hydrogen coupled with a variety of tritium sources, sinks, and permeation models. In the TPAC, ternary fission and neutron reactions with 6Li, 7Li 10B, and 3He were taken into considerations as tritium sources. Purification and leakage models were implemented as main tritium sinks. Permeation of tritium and H2 through pipes, vessels, and heat exchangers were considered as main tritium transport paths. In addition, electroyzer and isotope exchange models were developed for analyzing hydrogen production systems, including high temperature electrolysis and sulfur-iodine processes.

  19. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  20. Ethylene production by ODHE in catalytically modified Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ) membrane reactors.

    PubMed

    Lobera, M Pilar; Escolástico, Sonia; Garcia-Fayos, Julio; Serra, José M

    2012-08-01

    Process intensification by the integration of membranes and high-temperature reactors offers several advantages with regard to conventional process schemes, that is, energy saving, safe operation, reduced plant/unit size, and higher process performance, for example, higher productivity, catalytic activity, selectivity, or stability. We present the study of oxidative dehydrogenation of ethane at 850 °C on a catalytic membrane reactor based on a mixed ionic-electronic conducting membrane. The surface of the membrane made of Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ) has been activated by using different porous catalytic layers based on perovskites. The layer was deposited by screen printing, and the porosity and thickness was studied for the catalyst composition. The different catalyst formulations are based on partial substitution of A- and B-site atoms of doped strontium ferrite/cobaltites (A(0.6)Sr(0.4)Co(0.5)Fe(0.5)O(3-δ) and Ba(0.6)Sr(0.4)BO(3-δ)) and were synthesized by an ethylenediaminetetraacetic acid-citrate complexation route. The use of a disk-shaped membrane in the reactor enabled the direct contact of gaseous oxygen and hydrocarbons to be avoided, and thus, the ethylene content increased. High ethylene yields (up to ≈81 %) were obtained by using a catalytic coating based on Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-δ), which included macropores produced by the addition of graphite platelets into the screen-printing ink. The promising catalytic results obtained with this catalytically modified membrane reactor are attributed to the combination of 1) the high activity, as a result of the high temperature and oxygen species diffusing through the membrane; 2) the control of oxygen dosing and the low concentration of molecules in the gas phase; and 3) suitable fluid dynamics, which enables appropriate feed contact with the membrane and the rapid removal of products. PMID:22791570