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1

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

SciTech Connect

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.

NONE

1997-03-01

2

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

SciTech Connect

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.

Not Available

1992-12-01

3

Isotope Production at the Hanford Site in Richland, Washington  

SciTech Connect

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.

Ammoniums

1999-06-01

4

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

SciTech Connect

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.

Not Available

1980-08-01

5

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

SciTech Connect

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.

NONE

1995-08-01

6

Transfer of Plutonium-Uranium Extraction Plant and N Reactor irradiated fuel for storage at the 105-KE and 105-KW fuel storage basins, Hanford Site, Richland Washington  

SciTech Connect

The U.S. Department of Energy (DOE) needs to remove irradiated fuel from the Plutonium-Uranium Extraction (PUREX) Plant and N Reactor at the Hanford Site, Richland, Washington, to stabilize the facilities in preparation for decontamination and decommissioning (D&D) and to reduce the cost of maintaining the facilities prior to D&D. DOE is proposing to transfer approximately 3.9 metric tons (4.3 short tons) of unprocessed irradiated fuel, by rail, from the PUREX Plant in the 200 East Area and the 105 N Reactor (N Reactor) fuel storage basin in the 100 N Area, to the 105-KE and 105-KW fuel storage basins (K Basins) in the 100 K Area. The fuel would be placed in storage at the K Basins, along with fuel presently stored, and would be dispositioned in the same manner as the other existing irradiated fuel inventory stored in the K Basins. The fuel transfer to the K Basins would consolidate storage of fuels irradiated at N Reactor and the Single Pass Reactors. Approximately 2.9 metric tons (3.2 short tons) of single-pass production reactor, aluminum clad (AC) irradiated fuel in four fuel baskets have been placed into four overpack buckets and stored in the PUREX Plant canyon storage basin to await shipment. In addition, about 0.5 metric tons (0.6 short tons) of zircaloy clad (ZC) and a few AC irradiated fuel elements have been recovered from the PUREX dissolver cell floors, placed in wet fuel canisters, and stored on the canyon deck. A small quantity of ZC fuel, in the form of fuel fragments and chips, is suspected to be in the sludge at the bottom of N Reactor`s fuel storage basin. As part of the required stabilization activities at N Reactor, this sludge would be removed from the basin and any identifiable pieces of fuel elements would be recovered, placed in open canisters, and stored in lead lined casks in the storage basin to await shipment. A maximum of 0.5 metric tons (0.6 short tons) of fuel pieces is expected to be recovered.

NONE

1995-07-01

7

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

SciTech Connect

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.

Greenfield, Bryce A.

2009-12-20

8

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

9

Plutonium and tritium produced in the Hanford Site production reactors  

SciTech Connect

In a news release on December 7, 1993, the Secretary of Energy announced declassification action that included totals for plutonium and tritium production in the Hanford Site production reactors. This information was reported as being preliminary because it was not fully supported by documentation. Subsequently, production data were made available from the US Department of Energy-Headquarters (DOE-HQ) records that indicated an increase of about one and one-half metric tons in total plutonium production. The Westinghouse Hanford Company was tasked by the US Department of Energy-Richland Operations Office to substantiate production figures and DOE-HQ data and to provide a defensible report of weapons- (6 wt% {sup 240}Pu) and nonweapons- (fuels-)grade (nominally 9 wt% or higher {sup 240}Pu) plutonium and tritium production in the Hanford Site production reactors. The task was divided into three parts. The first part was to determine plutonium and tritium production based on available reported accountability records. The second part was to determine plutonium production independently by calculational checks based on reactor thermal power generation and plutonium conversion factors representing the various reactor fuels. The third part was to resolve differences, if they occurred, in the reported and calculational results. In summary, the DOE-HQ-reported accountability records of plutonium and tritium production were determined to be the most defensible record of Hanford Site reactor production. The DOE-HQ records were consistently supported by the independent calculational checks and the records of operational data. Total production quantities are 67.4 MT total plutonium, which includes 12.9 MT of nonweapons-grade plutonium. The total tritium production was 10.6 kg.

Roblyer, S.P.

1994-09-28

10

Engineering studies for the Surplus Production Reactor Decommissioning Project at the Hanford Site  

SciTech Connect

In 1942, the Hanford Site (near Richland, WA) was commissioned as a facility for the production of plutonium. On location there are nine water cooled, graphite-moderated plutonium production reactors, which are now retired from service. Because the reactors contain irradiated reactor components, and because the buildings that house the reactors are contaminated with low levels of reactivity, the DOE has determined that there is a need for action and that some form of decommissioning or continued surveillance and maintenance is necessary. This report discusses assessments of the alternatives which have determined that while continued surveillance and maintenance adequately isolates remaining radioactive materials from the environment and properly protects human health and safety; decontamination and decommissioning (D&D) will ultimately be necessary. The project is technically complex and will likely be designated as a Department of Energy (DOE) Major System Acquisition or Major Project.

Miller, R.L.; Powers, E.W. [Westinghouse Hanford Co., Richland, WA (United States); Usher, J.M. [Ebasco Services, Inc., Augusta, GA (United States); Yannitell, D.M. [Ebasco Services, Inc., Oak Ridge, TN (United States)

1993-10-01

11

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

SciTech Connect

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.

NONE

1995-03-01

12

Savannah River Site production reactor technical specifications. K Production Reactor  

SciTech Connect

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.

NONE

1996-02-01

13

New Production Reactors Program Plan  

SciTech Connect

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.

Not Available

1990-12-01

14

Richland Operations Office technology summary  

SciTech Connect

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.

Not Available

1994-05-01

15

Fission Product Release from SLOWPOKE-2 Reactors  

NASA Astrophysics Data System (ADS)

Increasing radiation fields at several SLOWPOKE -2 reactors fuelled with highly enriched uranium aluminum alloy fuel have begun to interfere with the daily operation of these reactors. To investigate this phenomenon, samples of reactor container water and gas from the headspace above the reactor were obtained at four SLOWPOKE-2 reactor facilities and examined by gamma ray spectroscopy methods. These radiation fields are due to the circulation of fission products within the reactor container vessel. The most likely source of the fission product release is an area of uranium-bearing material exposed to the coolant at the end weld line which originated at the time of fuel fabrication. The results of this study are compared with observations from an underwater visual examination of one core and the metallographic examination of archived fuel elements.

Harnden, Anne M. C.

16

Xanthan production in a plunging jet reactor  

Microsoft Academic Search

A plunging jet reactor (0.04–0.08 m3) was used for the production of the exopolysaccharide xanthan with Xanthomonas campestris. The microorganism was not affected by the pump shear force. Similar specific growth rates and xanthan space-time yields to those in other reactor types were achieved at much lower specific power input. The better oxygen sorption efficiency in the jet reactor overcompensated

Ahmed Zaidi; Purnendu Ghosh; Adrian Schumpe; Wolf-Dieter Deckwer

1991-01-01

17

SRS's production reactor severe-accident issues  

Microsoft Academic Search

Severe accident behavior in Al-U metal-fueled production reactors is sufficiently different from commercial oxide-fueled reactors that an ongoing research and development (R and D) effort is needed to resolve issues specific to metal-fueled systems. The severe-accident program at the Savannah River Site (SRS) is based on light water reactor (LWR) technology when appropriate. A direct application of severe-accident phenomena technology

P. G. Ellison; M. L. Hyder; P. R. Monson; M. J. Ades

1991-01-01

18

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

SciTech Connect

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.

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

1987-08-01

19

The Modular Helium Reactor for Hydrogen Production  

SciTech Connect

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.

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

2006-10-01

20

Alternatives to proposed replacement production reactors  

SciTech Connect

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.

Cullingford, H.S.

1981-06-01

21

Pebble Bed Reactor Dust Production Model  

SciTech Connect

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.

Abderrafi M. Ougouag; Joshua J. Cogliati

2008-09-01

22

Production of 89Sr in solution reactor.  

PubMed

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

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

23

Silicon production in a fluidized bed reactor  

NASA Technical Reports Server (NTRS)

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.

Rohatgi, N. K.

1986-01-01

24

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

SciTech Connect

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.

Not Available

1991-04-01

25

Green nanoparticle production using micro reactor technology  

NASA Astrophysics Data System (ADS)

The importance and potential of nanoparticles in daily life as well as in various industrial processes is becoming more predominant. Specifically, silver nanoparticles are increasingly applied, e.g. in clothes and wipes, due to their antibacterial properties. For applications in liquid phase it is advantageous to produce the nanoparticles directly in suspension. This article describes a green production of silver nanoparticles using micro reactor technology considering principles of green chemistry. The aim is to reveal the potential and constraints of this approach and to show, how economic and environmental costs vary depending on process conditions. For this purpose our research compares the proposed process with water-based batch synthesis and demonstrates improvements in terms of product quality. Because of the lower energy consumption and lower demand of cleaning agents, micro reactor is the best ecological choice.

Kück, A.; Steinfeldt, M.; Prenzel, K.; Swiderek, P.; Gleich, A. v.; Thöming, J.

2011-07-01

26

Feasibility study of a magnetic fusion production reactor  

Microsoft Academic Search

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

R. W. Moir

1986-01-01

27

NPR (New Production Reactor) capacity cost evaluation  

SciTech Connect

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.

none,

1988-07-01

28

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...

29

Selection of a toroidal fusion reactor concept for a magnetic fusion production reactor  

Microsoft Academic Search

The basic fusion driver requirements of a toroidal materials production reactor are considered. The tokamak, stellarator, bumpy torus, and reversed-field pinch are compared with regard to their demonstrated performance, probable near-term development, and potential advantages and disadvantages if used as reactors for materials production. Of the candidate fusion drivers, the tokamak is determined to be the most viable for a

D. L. Jassby

1987-01-01

30

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

SciTech Connect

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.

Not Available

1991-04-01

31

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

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.

Not Available

1991-04-01

32

The behavior of fission products during nuclear rocket reactor tests  

SciTech Connect

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.

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

1991-01-01

33

Continuous-flow biodiesel production using slit-channel reactors.  

PubMed

Slit-channel reactors are reactors whose active surface areas are orders of magnitude higher than those of micro-reactors but have low fabrication costs relative to micro-reactors. We successfully produced biodiesel with different degrees of conversion using homogeneous catalyst in the slit-channel reactor. The reactor performance shows that percent conversion of soybean oil to biodiesel increases with channel depth, as expected, due to more efficient mixing. Shallow slit-channels require short average residence times for complete product conversion. Present results show that the slit-channel reactor provides an improved performance over traditional batch reactors using homogeneous sodium alkoxide catalyst. It is aimed to couple the reactors with solid catalysts in converting soybean oil to biodiesel and implementation method is suggested. The cost advantages resulting from the ease of fabrication of slit-channel reactors over micro-reactors and how these factors relate to the oil conversion efficiency to biodiesel are briefly noted and discussed. PMID:21256742

Kalu, Egwu Eric; Chen, Ken S; Gedris, Tom

2011-03-01

34

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

Microsoft Academic Search

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

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

2005-01-01

35

Hydrogen Production via a Commerically Ready Inorganic membrane Reactor  

Microsoft Academic Search

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.

Paul Liu

2007-01-01

36

Fission product scrubbing system for a nuclear reactor  

Microsoft Academic Search

A fission product scrubbing system is described for a nuclear reactor including a containment building defining a containment space for accommodating reactor components, comprising (a) means defining a water tank in the containment building; (b) a dividing wall extending into the water tank for separating the water tank into a first and a second compartment; (c) means defining a collection

1986-01-01

37

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...

38

Richland Environmental Restoration Project management action process document  

SciTech Connect

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.

NONE

1996-04-01

39

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

SciTech Connect

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)

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

1981-04-01

40

Improving Jet Reactor Configuration for Production of Carbon Nanotubes  

NASA Technical Reports Server (NTRS)

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.

Povitsky, Alex

2000-01-01

41

Moving bed reactor for solar thermochemical fuel production  

SciTech Connect

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.

Ermanoski, Ivan

2013-04-16

42

Reactor power history from fission product signatures  

E-print Network

The purpose of this research was to identify fission product signatures that could be used to uniquely identify a specific spent fuel assembly in order to improve international safeguards. This capability would help prevent and deter potential...

Sweeney, David J.

2009-05-15

43

INEL advanced test reactor plutonium-238 production feasibility assessment  

SciTech Connect

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.

Schnitzler, B.G. (Idaho National Engineering Laboratory, P.O. Box 1625-1575, Idaho Falls, Idaho 83415 (United States))

1993-01-10

44

NOVEL REACTOR FOR THE PRODUCTION OF SYNTHESIS GAS  

SciTech Connect

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.

Vasilis Papavassiliou; Leo Bonnell; Dion Vlachos

2004-12-01

45

Applications of catalytic inorganic membrane reactors to refinery products  

Microsoft Academic Search

Catalytic membrane reactors are reviewed as applied to opportunities and applications within petroleum refineries. Since so many inorganic membranes take advantage of H2 permselectivity and H2 demands are increasing in a refinery, there are a number of interesting process applications being considered. H2 production can be enhanced by using Pd based membranes for dehydrogenation, oxydehydrogenation, and decomposition reactions. Permselective H2

J. N. Armor

1998-01-01

46

A Novel Membrane Reactor for Direct Hydrogen Production from Coal  

Microsoft Academic Search

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,

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

2004-01-01

47

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

Microsoft Academic Search

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,

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

2004-01-01

48

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

Microsoft Academic Search

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,

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

2004-01-01

49

Tritium distribution modeling in a Light Water New Production Reactor  

Microsoft Academic Search

The tritium distribution and tritium release pathways in a new light water production reactor were examined. A computer model was developed to track the tritium as it makes its way through the various plant systems and ends up either as a release to the atmosphere, the cooling tower blowdown or to the solid waste system. The model was designed to

Jaeckle

1989-01-01

50

Continuous production of lactic acid in a cell recycle reactor  

Microsoft Academic Search

The production of lactic acid from glucose has been demonstrated using a CSTR (continuous stirred-tank reactor) with cell\\u000a recycle. Studies were conducted withLactobacillus delbrueckii at a fermentation temperature of 42°C and a pH of 6.25. A cell density of 140 g dry weight\\/L and a volumetric productivity\\u000a of 150 g\\/L.h, with complete glucose consumption, were obtained. It was not possible

Eric Ohleyer; Harvey W. Blanch; Charles R. Wilke

1985-01-01

51

Richland Environmental Restoration Project management action process document  

SciTech Connect

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.

NONE

1996-04-01

52

Annual Energy Consumption Analysis Report for Richland Middle School  

Microsoft Academic Search

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

B. Liu

2003-01-01

53

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

SciTech Connect

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.

NONE

1997-07-01

54

Indication of anomalous heat energy production in a reactor device  

E-print Network

An experimental investigation of possible anomalous heat production in a special type of reactor tube named E-Cat HT is carried out. The reactor tube is charged with a small amount of hydrogen loaded nickel powder plus some additives. The reaction is primarily initiated by heat from resistor coils inside the reactor tube. Measurement of the produced heat was performed with high-resolution thermal imaging cameras, recording data every second from the hot reactor tube. The measurements of electrical power input were performed with a large bandwidth three-phase power analyzer. Data were collected in two experimental runs lasting 96 and 116 hours, respectively. An anomalous heat production was indicated in both experiments. The 116-hour experiment also included a calibration of the experimental set-up without the active charge present in the E-Cat HT. In this case, no extra heat was generated beyond the expected heat from the electric input. Computed volumetric and gravimetric energy densities were found to be fa...

Levi, Giuseppe; Hartman, Torbjörn; Höistad, Bo; Pettersson, Roland; Tegnér, Lars; Essén, Hanno

2013-01-01

55

Indication of anomalous heat energy production in a reactor device  

E-print Network

An experimental investigation of possible anomalous heat production in a special type of reactor tube named E-Cat HT is carried out. The reactor tube is charged with a small amount of hydrogen loaded nickel powder plus some additives. The reaction is primarily initiated by heat from resistor coils inside the reactor tube. Measurement of the produced heat was performed with high-resolution thermal imaging cameras, recording data every second from the hot reactor tube. The measurements of electrical power input were performed with a large bandwidth three-phase power analyzer. Data were collected in two experimental runs lasting 96 and 116 hours, respectively. An anomalous heat production was indicated in both experiments. The 116-hour experiment also included a calibration of the experimental set-up without the active charge present in the E-Cat HT. In this case, no extra heat was generated beyond the expected heat from the electric input. Computed volumetric and gravimetric energy densities were found to be far above those of any known chemical source. Even by the most conservative assumptions as to the errors in the measurements, the result is still one order of magnitude greater than conventional energy sources.

Giuseppe Levi; Evelyn Foschi; Torbjörn Hartman; Bo Höistad; Roland Pettersson; Lars Tegnér; Hanno Essén

2013-05-16

56

Solar water splitting for hydrogen production with monolithic reactors  

Microsoft Academic Search

The present work proposes the exploitation of solar energy for the dissociation of water and production of hydrogen via an integrated thermo-chemical reactor\\/receiver system. The basic idea is the use of multi-channelled honeycomb ceramic supports coated with active redox reagent powders, in a configuration similar to that encountered in automobile exhaust catalytic aftertreatment.Iron-oxide-based redox materials were synthesized, capable to operate

C. Agrafiotis; M. Roeb; A. G. Konstandopoulos; L. Nalbandian; V. T. Zaspalis; C. Sattler; P. Stobbe; A. M. Steele

2005-01-01

57

A new tubular reactor for mass production of microalgae outdoors  

Microsoft Academic Search

A novel reactor for outdoor production of microalgae is described. Air-lift is used for circulation of the culture in transparent tubes lying on the ground and interconnected by a manifold. Dissolved O2 is removed through a gas-separator placed 2.0 m above the tubes and water-spray is used for cooling. The manifold permits short-run durations between leaving the gas separator and

Amos Richmond; Sammy Boussiba; Avigad Vonshak; Reuven Kopel

1993-01-01

58

USE OF THE MODULAR HELIUM REACTOR FOR HYDROGEN PRODUCTION  

SciTech Connect

OAK-B135 A significant ''Hydrogen Economy'' is predicted that will reduce our dependence on petroleum imports and reduce pollution and greenhouse gas emissions. Hydrogen is an environmentally attractive fuel that has the potential to displace fossil fuels, but contemporary hydrogen production is primarily based on fossil fuels. The author has recently completed a three-year project for the US Department of Energy (DOE) whose objective was to ''define an economically feasible concept for production of hydrogen, using an advanced high-temperature nuclear reactor as the energy source''. Thermochemical water-slitting, a chemical process that accomplishes the decomposition of water into hydrogen and oxygen, met this objective. The goal of the first phase of this study was to evaluate thermochemical processes which offer the potential for efficient, cost-effective, large-scale production of hydrogen, and to select one for further detailed consideration. They selected the Sulfur-Iodine cycle. In the second phase, they reviewed all the basic reactor types for suitability to provide the high temperature heat needed by the selected thermochemical water splitting cycle and chose the helium gas-cooled reactor. In the third phase they designed the chemical flowsheet for the thermochemical process and estimated the efficiency and cost of the process and the projected cost of producing hydrogen. These results are summarized in this report.

SCHULTZ,KR

2003-09-01

59

Flow excursion experiments with a production reactor assembly mockup  

SciTech Connect

A series of power ramp and loss-of-coolant accidents were simulated with an electrically heated mockup of a Savannah River Site production reactor assembly. The one-to-one scale mockup had full multichannel annular geometry in its heated section in addition to prototypical inlet and outlet endfitting hardware. Power levels causing void generation and flow instability in the water coolant flowing through the mockup were found under different transient and quasi-steady state test conditions. A reasonably sharp boundary between initial operating powers leading to or not leading to flow instability were found: that being 0.2 MW or less on power levels of 4 to 6.3 MW. Void generation occurred before, but close to, the point of flow instability. The data were taken in support of the Savannah River reactor limits program and will be used in continuing code benchmarking efforts. 6 refs., 12 figs., 2 tabs.

Rush, G.C.; Blake, J.E. (Babcock and Wilcox Co., Alliance, OH (USA)); Nash, C.A. (Westinghouse Savannah River Co., Aiken, SC (USA))

1990-01-01

60

Preconceptual design of the new production reactor circulator test facility  

SciTech Connect

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.

Thurston, G.

1990-06-01

61

Fission product scrubbing system for a nuclear reactor  

SciTech Connect

A fission product scrubbing system is described for a nuclear reactor including a containment building defining a containment space for accommodating reactor components, comprising (a) means defining a water tank in the containment building; (b) a dividing wall extending into the water tank for separating the water tank into a first and a second compartment; (c) means defining a collection plenum normally hermetically sealed from the containment space and the environment externally of the containment building; (d) means defining a communication passage in the dividing wall underneath the water level in the first and second compartments for maintaining communication between the water stored in the first and second compartments; (e) a standpipe extending from the containment space into the second compartment; (f) a vent pipe extending from the collection plenum into the environment externally of the containment building; and (g) a rupture disc mounted in the vent pipe for normally blocking communication between the collection plenum and the environment.

Leach, D.S.

1986-09-09

62

Production of biodiesel using a continuous gas-liquid reactor.  

PubMed

A novel continuous reactor process has been developed for the production of biodiesel from fats and oils. The key feature of the process is its ability to operate continuously with a high reaction rate, potentially requiring less post reaction cleaning and product/reactant separation than currently established processes. This was achieved by atomising the heated oil/fat and then spraying it into a reaction chamber filled with methanol vapor in a counter current flow arrangement. This allows the continuous separation of product and the excess methanol stream in the reactor. The overall conversion based on a single cycle of this process has been between 50% and 96% of the feed stock materials. Conversions of 94-96% were achieved while operating with 5-7 g of sodium methoxide/L of methanol at methanol flow rate of 17.2 L/h and oil flow rate of 10 L/h. Additional variations in the reactant stoichiometry (i.e. reactant flow rates), catalyst type/concentration, and reaction temperature on the overall product conversion were investigated. PMID:18672363

Behzadi, Sam; Farid, Mohammed M

2009-01-01

63

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

SciTech Connect

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.

Jerde, E.A.; Glasgow, D.C. [Oak Ridge National Lab., TN (United States)

1998-09-01

64

Long-lived activation products in reactor materials  

SciTech Connect

The purpose of this program was to assess the problems posed to reactor decommissioning by long-lived activation products in reactor construction materials. Samples of stainless steel, vessel steel, concrete, and concrete ingredients were analyzed for up to 52 elements in order to develop a data base of activatable major, minor, and trace elements. Large compositional variations were noted for some elements. Cobalt and niobium concentrations in stainless steel, for example, were found to vary by more than an order of magnitude. A thorough evaluation was made of all possible nuclear reactions that could lead to long lived activation products. It was concluded that all major activation products have been satisfactorily accounted for in decommissioning planning studies completed to date. A detailed series of calculations was carried out using average values of the measured compositions of the appropriate materials to predict the levels of activation products expected in reactor internals, vessel walls, and bioshield materials for PWR and BWR geometries. A comparison is made between calculated activation levels and regulatory guidelines for shallow land disposal according to 10 CFR 61. This analysis shows that PWR and BWR shroud material exceeds the Class C limits and is, therefore, generally unsuitable for near-surface disposal. The PWR core barrel material approaches the Class C limits. Most of the remaining massive components qualify as either Class A or B waste with the bioshield clearly Class A, even at the highest point of activation. Selected samples of activated steel and concrete were subjected to a limited radiochemical analysis program as a verification of the computer model. Reasonably good agreement with the calculations was obtained where comparison was possible. In particular, the presence of /sup 94/Nb in activated stainless steel at or somewhat above expected levels was confirmed.

Evans, J.C.; Lepel, E.L.; Sanders, R.W.; Wilkerson, C.L.; Silker, W.; Thomas, C.W.; Abel, K.H.; Robertson, D.R.

1984-08-01

65

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

SciTech Connect

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.

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

2004-07-29

66

Extreme thermophilic biohydrogen production from wheat straw hydrolysate using mixed culture fermentation: Effect of reactor configuration  

Microsoft Academic Search

Hydrogen production from hemicellulose-rich wheat straw hydrolysate was investigated in continuously-stirred tank reactor (CSTR), up-flow anaerobic sludge bed (UASB) reactor, and anaerobic filter (AF) reactor. The CSTR was operated at an hydraulic retention time (HRT) of 3days, and the UASB and AF reactors were operated at 1day HRT, using mixed extreme thermophiles at 70°C. The highest hydrogen production yield of

Prawit Kongjan; Irini Angelidaki

2010-01-01

67

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

SciTech Connect

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.

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

2004-04-26

68

(COMEDIE program review and fission product transport in MHTGR reactor)  

SciTech Connect

The subcontract between Martin Marietta Energy Systems, Inc., and the CEA provides for the refurbishment of the high pressure COMEDIE test loop in the SILOE reactor and a series of experiments to characterize fission product lift-off from MHTGR heat exchanger surfaces under several depressurization accident scenarios. The data will contribute to the validation of models and codes used to predict fission product transport in the MHTGR. In the meeting at CEA headquarters in Paris the program schedule and preparation for the DCAA and Quality Assurance audits were discussed. Long-range interest in expanded participation in the gas-cooled reactor technology Umbrella Agreement was also expressed by the CEA. At the CENG, in Grenoble, technical details on the loop design, fabrication components, development of test procedures, and preparation for the DOE quality assurance (QA) audit in May were discussed. After significant delays in CY 1989 it appears that good progress is being made in CY 1990 and the first major test will be initiated by December. An extensive list of agreements and commitments was generated to facilitate the coordination and planning of future work. 2 figs., 2 tabs.

Stansfield, O.M.

1990-03-15

69

Uncertainties in the Anti-neutrino Production at Nuclear Reactors  

E-print Network

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 electron anti-neutrino detectors is examined. We discuss reactor-to-reactor correlations between the leading uncertainties and their relevance to reactor anti-neutrino experiments.

Z. Djurcic; J. A. Detwiler; A. Piepke; V. R. Foster Jr.; L. Miller; G. Gratta

2008-08-06

70

Biological hydrogen production in suspended and attached growth anaerobic reactor systems  

Microsoft Academic Search

Biological production of hydrogen gas has received increasing interest from the international community during the last decade. Most studies on biological fermentative hydrogen production from carbohydrates using mixed cultures have been conducted in conventional continuous stirred tank reactors (CSTR) under mesophilic conditions. Investigations on hydrogen production in reactor systems with attached microbial growth have recently come up as well as

Hariklia N. Gavala; Ioannis V. Skiadas; Birgitte K. Ahring

2006-01-01

71

Multiscale Modeling of TiO2 Nanoparticle Production in Flame Reactors: Effect of Chemical Mechanism  

E-print Network

Multiscale Modeling of TiO2 Nanoparticle Production in Flame Reactors: Effect of Chemical Mechanism manufactured in flame reactors, the precursor is injected into a pre-existing flame, exposing it to a high) on the prediction of nanoparticle nucleation is investigated using a plug-flow reactor and a partially stirred tank

Raman, Venkat

72

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

SciTech Connect

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.

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

2004-01-22

73

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

NASA Astrophysics Data System (ADS)

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.

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

2010-11-01

74

Enhancement of Energy Yield for Ozone Production via Packed-Bed Reactors  

Microsoft Academic Search

The present work aims to enhance the energy yield of ozone production via packed-bed reactors. It has been experimentally demonstrated that ozone concentration and corresponding energy yield achieved by packed-bed reactors are significantly higher than that achieved by DBD only. The so-called packed-bed reactor is constructed by packing granular dielectric pellets within a DBD reactor. Two kinds of dielectric materials

Hsin Liang Chen; How Ming Lee; Moo Been Chang

2006-01-01

75

Tritium distribution modeling in a Light Water New Production Reactor  

SciTech Connect

The tritium distribution and tritium release pathways in a new light water production reactor were examined. A computer model was developed to track the tritium as it makes its way through the various plant systems and ends up either as a release to the atmosphere, the cooling tower blowdown or to the solid waste system. The model was designed to predict the integrated yearly tritium releases and provide estimated airborne tritium concentrations in various locations within the plant. WNP-1 was used as a representative model for a Light Water New Production Reactor (LWNPR). The Tritium Distribution Model solves for the time dependent tritium concentration in a system of nodes. These nodes are connected to one another via a set of internodal flow paths and to various sources and sinks. For example, plant systems such as the primary system are the nodes, piping and leaks are the internodal flow paths, make-up water is a source, and release to the atmosphere is a sink. The expected water mass of each node; the flow rates between nodes, sources, and sinks; and tritium source rates are provided as input. The code will solve for the time dependent tritium concentration in each node and the amount of tritium ''released'' to the sinks. Preliminary calculations have been performed using WNP-1 plant specific information obtained primarily from the WNP-1 FSAR. Further work is currently in progress to refine the model and provide a more realistic set of input values which will better represent an operating LWNPR. 1 ref., 1 fig., 1 tab.

Jaeckle, J.W.

1989-05-01

76

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

SciTech Connect

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%.

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

2004-10-26

77

An Assessment of Reactor Types for Thermochemical Hydrogen Production  

Microsoft Academic Search

Nuclear energy has been proposed as a heat source for producing hydrogen from water using a sulfur-iodine thermochemical cycle. This document presents an assessment of the suitability of various reactor types for this application. The basic requirement for the reactor is the delivery of 900 C heat to a process interface heat exchanger. Ideally, the reactor heat source should not

ALBERT C

2002-01-01

78

Extracting Silicon Product From Fluidized-Bed Reactors  

NASA Technical Reports Server (NTRS)

Silicon particles continuously removed from bottom of fluidizedbed reactor when grown to large size. In reactor, silane (SiH4) flows through bed of small silicon seed particles at temperature of 650 degrees to 700 degrees C. Silane decomposes into silicon vapor and hydrogen gas, and vapor deposits as solid on seed particles. With withdrawal system, reactor operates continuously.

Hsu, G. C.; Rohatgi, N. K.; Morrison, A. D.

1986-01-01

79

A NOVEL MEMBRANE REACTOR FOR DIRECT HYDROGEN PRODUCTION FROM COAL  

SciTech Connect

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.

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

2005-04-28

80

Hydrogen Production Via a Commercially Ready Inorganic Membrane Reactor  

SciTech Connect

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.

Paul K. T. Liu

2006-09-30

81

Hydrogen Production via a Commerically Ready Inorganic membrane Reactor  

SciTech Connect

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.

Paul Liu

2007-06-30

82

Methane production using whole and screened dairy manure in conventional and fixed-film reactors  

SciTech Connect

The technical feasibility of adopting the fixed-film reactor concept for biogas production from screened dairy manure was investigated. The methane production capability of laboratory-scale 4-L anaerobic reactors (conventional and fixed-film) receiving screened dairy manure and operated at 35/sup 0/C was compared. Dairy manure filtrate with 4.4% total solids (TS) and 3.4% volatile solids (VS) (average value) was prepared from 1:1 manure-water slurry. The feed material was added intermittently at loading rates ranging from 2.34 to 25 and 2.25 to 785 g VS/L d, respectively, for the conventional and fixed-film reactors. Maximum methane production rate (L CH/sub 4//L d) for the conventional reactor was 0.63 L CH/sub 4//L d achieved at a 6-day hydraulic retention time (HRT). For the fixed-film reactor the maximum production rate was 3.53 L CH/sub 4//L d when operated at a loading rate of 262 g VS/L d (3 h HRT). The fixed film reactor was capable of sustaining a loading of 785 g VS/L d (1 h HRT). The fixed-film reactor performed much better than the conventional reactors. These results indicate that a large reduction of required reactor volume is possible through application of a fixed-film concept combined with a liquid-solid separation pretreatment of dairy manure.

Liao, P.H.; Lo, K.V.

1985-01-01

83

A Novel Membrane Reactor for Direct Hydrogen Production from Coal  

SciTech Connect

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. 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 successfully tested in the new permeation unit. During this reporting period, two different types of membranes, Eu-doped SrCeO{sub 3} (SCE) and SrCe{sub 0.95}Tm{sub 0.05}O{sub 3} (SCTm) provided by the University of Florida and the University of Cincinnati, respectively were tested in the high pressure permeation unit. The SCTm membrane, with a thickness of 1.7 mm, showed the highest hydrogen permeability among the perovskite membranes tested in this project so far. The hydrogen flux measured for the SCTm membrane was close to 0.8 cc/min/cm{sup 2} at a hydrogen feed pressure of about 4 bar at 950 C. SEM and EDX analysis for the tested SCTm membrane showed a separate Ce-rich phase deposited along the grain boundaries in the region towards the feed side of the membrane. No such phase separation was observed towards the permeate side. Partial reduction of the SCTm perovskite material by the high pressure hydrogen, especially in the feed side of the membrane, was postulated to be the possible reason for the phase separation. Further investigation of the stability issue of the perovskite membrane is needed.

Shain Doong, Estela Ong; Mike Atroshenko; Francis Lau; Mike Robers

2004-12-31

84

Method of Fission Product Beta Spectra Measurements for Predicting Reactor Anti-neutrino Emission  

E-print Network

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 anti-neutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to current 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 re-considerations 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 i...

Asner, D M; Campbell, L W; Greenfield, B; Kos, M S; Orrell, J L; Schram, M; VanDevender, B; Wood, 1 L S; Wootan, D W

2014-01-01

85

Anaerobic treatment of biodiesel by-products in a pilot scale reactor  

Microsoft Academic Search

In this work, long-term operation of a pilot scale mixed anaerobic reactor processing crude glycerol and rapeseed meal is\\u000a discussed. These materials are generated as by-products of biodiesel production. Mixed reactor was operated under mesophilic\\u000a conditions for the period of 654 days. Total cumulative production of biogas reached 379 m3 (at atmospheric pressure and ambient temperature). Maximum volumetric loading achieved

Nina Kolesárová; Miroslav Hut?an; Viera Špalková; Rastislav Kuffa; Igor Bodík

2011-01-01

86

Recent BeO-reflector-controlled reactor experiments in ZPPR  

NASA Astrophysics Data System (ADS)

Integral reactor physics measurements were performed on a BeO-reflected fast reactor assembly in the Zero Power Plutonium Reactor Facility during January and February of 1985. The measurements emphasized power distributions and reflector control worths in two different critical states. The measurements have been analyzed using three-dimensional deterministic and Monte Carlo methods and the ENDF/B-V.2 nuclear data library. Together the measurements and analyses form a modern, reliable, benchmark data set for testing calculational methods that will be used in predicting some of the design parameters for future space reactors.

McFarlane, Harold F.; Brumbach, Stephen B.; Carpenter, Stuart G.; Collins, Peter J.; McKnight, Richard D.

87

Design of immobilized enzyme reactors for the continuous production of fructose syrup from whey permeate  

Microsoft Academic Search

Biocatalyst inactivation is inherent to continuous operation of immobilized enzyme reactors, meaning that a strategy must exist to ensure a production of uniform quality and constant throughput. Flow rate can be profiled to compensate for enzyme inactivation maintaining substrate conversion constant. Throughput can be maintained within specified margins of variation by using several reactors operating in parallel but displaced in

A. Illanes; L. Wilson; L. Raiman

1999-01-01

88

Radiation effects in Be and Al for a magnetic fusion production reactor  

NASA Astrophysics Data System (ADS)

Estimates of the expected performance of beryllium and several aluminum alloy structural components of the breeding blanket of a magnetic fusion production reactor are made based on the known behavior and properties of these materials in fission reactor applications. Comparisons of the irradiation damage effects resulting from the fission reactor neutron spectra and the fusion reactor blanket spectra indicate that beryllium will perform well in the breeding blanket for at least one year and the aluminum alloy 5052 will retain structural integrity for about 5 years.

Mitchell, J. B.

1986-12-01

89

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

SciTech Connect

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.

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

1989-11-15

90

Multiscale hydrodynamic investigation to intensify the biogas production in upflow anaerobic reactors.  

PubMed

Hydrodynamics plays a main role for the performance of an anaerobic reactor involving three phases: wastewater, sludge granules and biogas bubbles. The present work was focused on an original approach to investigate the hydrodynamics at different scales and then to intensify the performance of such complex reactors. The experiments were carried out respectively in a 3D reactor at macroscale, a 2D reactor at mesoscale and a 1D anaerobic reactor at microscale. A Particle Image Velocimetry (PIV), a micro-PIV and a high-speed camera were employed to quantify the liquid flow fields and the relative motion between sludge granules and bubbles. Shear rates exerted on sludge granules were quantified from liquid flow fields. The optimal biogas production is obtained at mean shear rate varying from 28 to 48s(-1), which is controlled by two antagonistic mechanisms. The multiscale approach demonstrates pertinent mechanisms proper to each scale and allows a better understanding of such reactors. PMID:24398185

Jiang, Jiankai; Wu, Jing; Zhang, Jinbai; Poncin, Souhila; Li, Huai Z

2014-03-01

91

Antibody production in packed bed reactors using serum-free and protein-free medium  

Microsoft Academic Search

The present work demonstrates the utility of packed bed reactors for the production of monoclonal antibody. We present data from a continuous process run for the production of over 100 grams of antibody, using serum-free medium. An additional pilot run also demonstrates the potential for continued antibody production under protein-free conditions, using a standard basal medium.

R. Bliem; R. Oakley; K. Matsuoka; R. Varecka; V. Taiariol

1990-01-01

92

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

Microsoft Academic Search

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

2004-01-01

93

A Fisheries Evaluation of the Richland and Wapato Canal Fish Screening Facilities, Spring 1987 : Annual Report  

Microsoft Academic Search

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

Duane A. Neitzel; C. Scott Abernethy; E. William Lustry; Sally J. Wampler

1988-01-01

94

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

SciTech Connect

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.

Not Available

1992-10-01

95

Routine environmental audit of the Hanford Site, Richland, Washington  

SciTech Connect

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.

Not Available

1994-05-01

96

Tritium concentrations in the Columbia River at Richland  

SciTech Connect

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.

Dirkes, R.L.

1993-01-01

97

A Novel Membrane Reactor for Direct Hydrogen Production From Coal  

Microsoft Academic Search

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

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

2006-01-01

98

Non-adiabatic radial-flow reactor for styrene production  

Microsoft Academic Search

A non-adiabatic radial reactor is proposed to carry out the dehydrogenation of ethylbenzene to styrene. Radial flow and continuous heating (using superheated steam) are the main features of the new design. Steam used as heating medium flows through tubes, which are radially installed in the catalyst bed. By means of steady-state simulations, this new design has been compared with two

A. A. Savoretti; D. O. Borio; V. Bucalá; J. A. Porras

1999-01-01

99

Method of Fission Product Beta Spectra Measurements for Predicting Reactor Anti-neutrino Emission  

E-print Network

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 anti-neutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to current 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 re-considerations 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.

D. M. Asner; K. Burns; L. W. Campbell; B. Greenfield; M. S. Kos; J. L. Orrell; M. Schram; B. VanDevender; 1 L. S. Wood; D. W. Wootan

2014-03-01

100

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

SciTech Connect

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.

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

1994-01-01

101

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

SciTech Connect

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)

Schilperoort, Daryl L.; Faulk, Darrin [Washington Closure Hanford, 2620 Fermi Avenue, Richland, Washington 99352 (United States)] [Washington Closure Hanford, 2620 Fermi Avenue, Richland, Washington 99352 (United States)

2013-07-01

102

Innovative microbial fuel cell for electricity production from anaerobic reactors  

Microsoft Academic Search

A submersible microbial fuel cell (SMFC) was developed by immersing an anode electrode and a cathode chamber in an anaerobic reactor. Domestic wastewater was used as the medium and the inoculum in the experiments. The SMFC could successfully generate a stable voltage of 0.428±0.003V with a fixed 470? resistor from acetate. From the polarization test, the maximum power density of

Booki Min; Irini Angelidaki

2008-01-01

103

Corrosion of Fast-Reactor Claddings by Physical and Chemical Interaction with Fuel and Fission Products  

Microsoft Academic Search

Fuel-cladding chemical interaction in fast breeder reactor (FBR) fuel pins can cause both matrix and intergranular corrosion of the inner surface of the cladding. Matrix corrosion is uniform nonselective interaction with fuel and fission products, causing the cladding to thin. Intergranular corrosion occurs on grain boundaries, weakening both them and the grains. Interaction with fission products may be the cause

V. A. TZYKANOV; V. N. GOLOVANOV; V. K. SHAMARDIN; F. N. KRYUKOV; A. V. POVSTYANKO

104

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

NASA Astrophysics Data System (ADS)

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).

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

2014-09-01

105

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

SciTech Connect

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.

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

1995-02-01

106

Determination of apparent kinetic parameters for competitive product inhibition in packed-bed immobilized enzyme reactors  

Microsoft Academic Search

In this study, a simple and effective technique for characterizing Michaelis–Menten type kinetics with competitive product inhibition in packed-bed re-circulated immobilized enzyme reactors is presented, where the use of nonlinear regression techniques for multi-parameter estimation are not required. In order to demonstrate the new technique introduced in this work, enzymatic conversion of lactose in a recycling packed-bed reactor is envisaged

Ahmet R. Özdural; Deniz Tanyolaç; ?smail H. Boyac?; Mehmet Mutlu; Colin Webb

2003-01-01

107

Effect of reactor configuration on biogas production from wheat straw hydrolysate  

Microsoft Academic Search

The potential of wheat straw hydrolysate for biogas production was investigated in continuous stirred tank reactor (CSTR) and up-flow anaerobic sludge bed (UASB) reactors. The hydrolysate originated as a side stream from a pilot plant pretreating wheat straw hydrothermally (195°C for 10–12min) for producing 2nd generation bioethanol [Kaparaju, P., Serrano, M., Thomsen, A.B., Kongjan, P., Angelidaki, I., 2009. Bioethanol, biohydrogen

Prasad Kaparaju; María Serrano; Irini Angelidaki

2009-01-01

108

Fission product release from uranium-aluminum alloy fuel in Slowpoke-2 reactors  

SciTech Connect

Increasing, but still low, radiation fields due to a release of fission products have been observed in the light-water-filled reactor container of SLOWPOKE-2 reactors fueled with a highly enriched uranium alloy. To investigate this phenomenon, samples of water coolant and headspace gas from the reactor container have been examined by gamma spectroscopy methods for several reactors with various burnup. A model has been developed to describe the kinetic behavior of the activity concentrations of the short-lived iodine and noble gas species in the reactor container water, and the noble gas concentrations in the reactor container head-space. The most likely source of the fission product release is an area of uranium-bearing material exposed to the coolant at the end weld line of the fuel elements that originated at the time of fuel fabrication. The fission product release analysis is consistent with observations from an underwater visual examination of a high-burnup core and a metallographic examination of archived fuel elements.

Lewis, B.J.; Harnden-Gillis, A.C.; Bennett, L.G.I. (Royal Military Coll. of Canada, Kingston, Ontario (Canada). Dept. of Chemistry and Chemical Engineering)

1994-03-01

109

MHTGR: New production reactor summary of experience base  

SciTech Connect

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.

Not Available

1988-03-01

110

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

Microsoft Academic Search

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

C. Bergren; M. Flora; H. Belencan

2010-01-01

111

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

Microsoft Academic Search

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

Bergren

2009-01-01

112

Effect of volatile retention on the products from low temperature pyrolysis in a fixed bed batch reactor  

Microsoft Academic Search

This study looks at the effect of volatile retention, within a batch reactor, on the products from fixed bed coal pyrolysis. It has been found that increased retention of volatiles within the reactor can increase the specific calorific value of the solid product. Increased confinement can also increase the specific calorific value of the gas, by increasing the production of

M Cloke; E Lester; M Leney

1999-01-01

113

Modeling and simulation of corrosion product activity in pressurized water reactors under power perturbations  

Microsoft Academic Search

An improved methodology is presented for simulation of coolant activation due to corrosion products and impurities in a typical pressurized water reactor (PWR) under power perturbations. Using time dependent production and losses of corrosion products in the primary coolant path an approach has been developed to calculate the coolant specific activity. Results for 24Na, 56Mn, 59Fe, 60Co and 99Mo show

Farah Deeba; Anwar M Mirza; Nasir M Mirza

1999-01-01

114

Continuous production of monoacylglycerols from palm olein in packed-bed reactor with immobilized lipase PS  

Microsoft Academic Search

A packed-bed reactor (PBR) system using immobilized lipase PS as biocatalyst was developed for continuous monoacylglycerols (MAG) production. The condition for continuous MAG production using immobilized lipase PS (IM-PS) of 1.5g (550U) in PBR (0.68cm i.d., 25cm long) was optimized. The effect of molar ratio of glycerol to palm olein, water content in glycerol and residence time on MAG production

Aran H-Kittikun; Wiphum Kaewthong; Benjamas Cheirsilp

2008-01-01

115

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

SciTech Connect

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.

Not Available

1994-02-01

116

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

SciTech Connect

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.

Sai, P.M.S.; Ahmed, J. [Bhabha Atomic Research Centre, Kalpakkam (India). Centralised Waste Management Facility; Krishnaiah, K. [Indian Inst. of Tech., Madras (India). Dept. of Chemical Engineering

1997-09-01

117

Assessment of Natural Gas Splitting with a Concentrating Solar Reactor for Hydrogen Production  

SciTech Connect

Hydrogen production via thermal decomposition of methane using a solar reactor is analyzed for two different applications: (1) for a fueling station and (2) for power production. For the fueling station, the selling price of hydrogen is controlled by the high cost of hydrogen storage and compression, combined with storage limitations of the system, which prevents maximum hydrogen production. Two alternate scenarios to lower the hydrogen production cost are evaluated: (1) sending the hydrogen directly to a pipeline network and (2) adding a small electric heater, which provides heat to the solar reactor when the hydrogen supply is low. For power production, the economics of two options for the carbon produced from the solar process are evaluated: (1) selling the carbon black and (2) burning the carbon to produce more power.

Spath, P. L.; Amos, W. A.

2002-04-01

118

Sensitivity studies of loss-of-coolant accidents in the Savannah River production reactors  

SciTech Connect

Loss-of-coolant accident (LOCA) analyses were completed using the Transient Reactor Analysis Code (TRAC) to support the U.S. Department of Energy efforts to restart the production reactors located at the Savannah River Site. The break location and pump operation after the LOCA were the parameters varied for these sensitivity studies. Three location of double-ended guillotine break were studied: plenum inlet, pump suction, and pump discharge. Three pump operation scenarios were also studied: continued operation of both ac and dc pumps, tripping of the ac motor at 2 s after the LOCA, and tripping of the ac motor at 200 s after the LOCA. The production reactors use low pressure and temperature heavy water as the process fluid. The reactor has a moderator tank that contains the fuel channels. Above the moderator tank is an upper plenum that distributes the heavy water to each fuel assembly. The heavy water flows down through the fuel channels and into the moderator tank. From the tank, the water is pumped back to the upper plenum through six loops. Each loop contains a pump and two heat exchangers. Four of the loops have an emergency core coolant system (ECCS) connection. This TRAC model has been benchmarked extensively against data taken in the actual reactors or in prototypical models of the components of the reactors. The calculations were completed using a version of TRAC-PF1/MOD 2 that was updated to include heavy water properties and other changes that are specific to the production reactors.

Edwards, J.N.; Motley, F.E.; Morgan, M.M.; Knight, T.D.; Fischer, S.R. (Los Alamos National Lab., NM (USA))

1990-01-01

119

Numerical simulation of vortex pyrolysis reactors for condensable tar production from biomass  

SciTech Connect

A numerical study is performed in order to evaluate the performance and optimal operating conditions of vortex pyrolysis reactors used for condensable tar production from biomass. A detailed mathematical model of porous biomass particle pyrolysis is coupled with a compressible Reynolds stress transport model for the turbulent reactor swirling flow. An initial evaluation of particle dimensionality effects is made through comparisons of single- (1D) and multi-dimensional particle simulations and reveals that the 1D particle model results in conservative estimates for total pyrolysis conversion times and tar collection. The observed deviations are due predominantly to geometry effects while directional effects from thermal conductivity and permeability variations are relatively small. Rapid ablative particle heating rates are attributed to a mechanical fragmentation of the biomass particles that is modeled using a critical porosity for matrix breakup. Optimal thermal conditions for tar production are observed for 900 K. Effects of biomass identity, particle size distribution, and reactor geometry and scale are discussed.

Miller, R.S.; Bellan, J. [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.

1998-08-01

120

Hydrogen Production by High Temperature Electrolysis with Nuclear Reactor  

SciTech Connect

In this paper, we report our design of high temperature electrolysis plant system and the analysis results. The system efficiency increases with the increase of the steam utilization in the solid oxide electrolysis cell (SOEC) or the decrease of the hydrogen recycle (hydrogen recycle flow to product hydrogen flow) ratio,. The system efficiency is nearly independent of the SOEC operating temperature and pressure, and the air to product O{sub 2} ratio. In this study, the maximum system efficiency is 56.3%. (authors)

Ogawa, Takashi; Fujiwara, Seiji; Kasai, Shigeo; Yamada, Kazuya [Toshiba Corporation: 1 Toshiba-cho, Fuchu, Tokyo, 183-8511 (Japan)

2007-07-01

121

GAMMA SPECTRA OF GROSS FISSION PRODUCTS FROM THERMAL REACTORS  

Microsoft Academic Search

Calculations of gamma spectra from products of thermal fission of U\\/sup ; 235\\/ are presented. The fission yield values and decay data used are taken from ; literature published up to April 1958. The calculations cover seven different ; irradiation times from one day to two years and continuous cooling times from one ; day to 1000 years. The gamma

J. Prawitz; K. Low; R. Bjornerstedt

1959-01-01

122

Pyrolysis of rapeseed in a free fall reactor for production of bio-oil  

Microsoft Academic Search

Pyrolysis experiments of rapeseed (Brassica napus L.) were performed in a free fall reactor at atmospheric pressure under nitrogen atmosphere. The effects of final pyrolysis temperature, particle size and sweep gas flow rate on the yields of products were investigated. The temperature of pyrolysis, particle size and sweep gas flow rate were varied in the ranges of 400—700 °C, ?0.224

Ozlem Onay; O. Mete Koçkar

2006-01-01

123

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

Microsoft Academic Search

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

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

1995-01-01

124

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

SciTech Connect

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.

M. J. Russell

2006-06-01

125

Detailed steady-state simulation of tubular reactors for LDPE production: Influence of numerical integration accuracy  

Microsoft Academic Search

Simulators are widely used for analyzing and optimizing the production of low density polyethylene in tubular reactors under steady state conditions. This steady state is in practice often simulated by chemical engineers using a series of CSTRs type model due to its stable behavior with respect to spatial discretization and smooth convergence for the underlying stiff model equations. Although already

Peter M. M. Van Erdeghem; Filip Logist; Christoph Dittrich; Jan F. Van Impe

126

Switching from water to ionic liquids for the production of methylchloride: Catalysis and reactor issues  

Microsoft Academic Search

The synthesis of methyl chloride from methanol and hydrogen chloride catalysed by zinc chloride was investigated in water and in two room temperature ionic liquids in a CSTR reactor. Both Aliquat336 and BMICl drive to similar rate of reactions as the traditional process albeit at lower temperatures. More importantly, the formation of the side product Me2O is decreased in ionic

Nicolas Dupont; Pierre Grenouillet; Frédéric Bornette; Claude de Bellefon

2009-01-01

127

Venting of fission products and shielding in thermionic nuclear reactor systems  

NASA Technical Reports Server (NTRS)

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.

Salmi, E. W.

1972-01-01

128

Hydrogen production by catalytic cracking of methane over nickel gauze under periodic reactor operation  

Microsoft Academic Search

The catalytic cracking of methane over nickel gauze is proposed as an attractive alternative for the production of CO-free hydrogen. The catalyst deactivates due to intensive coke deposition. Therefore, the reactor was operated periodically with the reaction followed by the catalyst regeneration by burning of coke in oxidative atmosphere. The optimal reaction performance was found to consist of reaction periods

B. Monnerat; L. Kiwi-Minsker; A. Renken

2001-01-01

129

Use of the confined impinging jet reactor for production of nanoscale iron oxide particles  

Microsoft Academic Search

The confined impinging jet reactor gives efficient mixing performance as required for fast reactions. In this work the mixing performance of CIJR is characterized through three measures: estimates of the energy dissipation, micromixing efficiency based on the yield of a homogeneous (iodide-iodate) reaction and particle size resulting from a heterogeneous (iron oxide) precipitation reaction. Whereas product yield and energy dissipation

Shad Waheed Siddiqui

2009-01-01

130

Uncertainty Analysis on Fission Molybdenum Production with a Nuclear Fuel Target in a Research Reactor  

Microsoft Academic Search

The use of a low-enriched uranium (LEU) fuel target was examined for the feasibility of ⁹⁹Mo production in a High-flux Advanced Neutron Application Reactor (HANARO). Uncertainty analysis was done with respect to the ⁹⁹Mo yield ratio, ²³⁹Pu yield ratio, annual production rate, and decontamination requirement. Validity of a coupled code system, MCNP\\/ORIGEN2, was evaluated to estimate reliable isotopic number densities

Dong-Keun Cho; Myung-Hyun Kim

2003-01-01

131

Simulation of municipal solid waste gasification for syngas production in fixed bed reactors  

Microsoft Academic Search

This study proposes a model of syngas production from municipal solid waste (MSW) gasification with air in fixed bed reactors.\\u000a The model (using Aspen plus simulator) is used to predict the results of MSW gasification and to provide some process fundamentals\\u000a concerning syngas production from MSW gasification. The effects of gasification temperature, air equivalence ratio and moisture\\u000a concentration on the

Chong Chen; Yu-qi Jin; Jian-hua Yan; Yong Chi

2010-01-01

132

Production of a gadolinium-loaded liquid scintillator for the Daya Bay reactor neutrino experiment  

NASA Astrophysics Data System (ADS)

We report on the production and characterization of liquid scintillators for the detection of electron antineutrinos by the Daya Bay reactor neutrino experiment. A 185 tons of gadolinium-loaded (0.1% by mass) liquid scintillator (Gd-LS) and a 200 tons of unloaded liquid scintillator (LS) were successfully produced from a linear-alkylbenzene (LAB) solvent in 6 months. The scintillator properties, the production and purification systems, and the quality assurance and control (QA/QC) procedures are described.

Beriguete, Wanda; Cao, Jun; Ding, Yayun; Hans, Sunej; Heeger, Karsten M.; Hu, Liangming; Huang, Aizhong; Luk, Kam-Biu; Nemchenok, Igor; Qi, Ming; Rosero, Richard; Sun, Hansheng; Wang, Ruiguang; Wang, Yifang; Wen, Liangjian; Yang, Yi; Yeh, Minfang; Zhang, Zhiyong; Zhou, Li

2014-11-01

133

Biological hydrogen production in an anaerobic sequencing batch reactor: pH and cyclic duration effects  

Microsoft Academic Search

An anaerobic sequencing batch reactor (ASBR) was used to evaluate biological hydrogen production from carbohydrate-rich organic wastes. The goal of the proposed project was to investigate the effects of pH (4.9, 5.5, 6.1, and 6.7), and cyclic duration (4, 6, and 8h) on hydrogen production. With the ASBR operated at 16-h HRT, 25g COD\\/L, and 4-h cyclic duration, the results

Wen-Hsing Chen; Shihwu Sung; Shen-Yi Chen

2009-01-01

134

Biohydrogen production using an up-flow anaerobic sludge blanket reactor  

Microsoft Academic Search

Sewage sludge was acclimated to establish H2-producing enrichment cultures for converting sucrose (20gCOD\\/l) into H2 in an up-flow anaerobic sludge blanket (UASB) reactor. The operating hydraulic retention times (HRTs) were 24–4h. The experimental results indicated that this UASB system could be used for hydrogen production. The hydrogen productivity was HRT dependent and nearly constant at the HRT of 8–20h. However,

Feng-Yung Chang; Chiu-Yue Lin

2004-01-01

135

Development of a novel integrated continuous reactor system for biocatalytic production of biodiesel.  

PubMed

A novel integrated immobilized enzyme-reactor system involving a continuous stirred tank reactor with two packed bed reactors in series was developed for the continuous production of biodiesel. The problem of methanol solubility into oil was solved by introducing a stirred tank reactor to dissolve methanol into partially converted oil. This step made the process perfectly continuous without requiring any organic solvent and intermittent methanol addition in the process. The substrate feeding rate of 0.74 mL/min and enzyme loading of 0.75 g per reactor were determined to be optimum for maximum biodiesel yield. The integrated continuous process was stable up to 45 cycles with biodiesel productivity of 137.2 g/L/h, which was approximately 5 times higher than solvent free batch process. In comparison with the processes reported in literature using expensive Novozyme 435 and hazardous organic solvent, the present process is completely green and perfectly continuous with economic and environmental advantages. PMID:24001564

Chattopadhyay, Soham; Sen, Ramkrishna

2013-11-01

136

A molten Salt Am242M Production Reactor for Space Applications  

NASA Technical Reports Server (NTRS)

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.

Emrich, William

2005-01-01

137

Effect of reactor configuration on biogas production from wheat straw hydrolysate.  

PubMed

The potential of wheat straw hydrolysate for biogas production was investigated in continuous stirred tank reactor (CSTR) and up-flow anaerobic sludge bed (UASB) reactors. The hydrolysate originated as a side stream from a pilot plant pretreating wheat straw hydrothermally (195 degrees C for 10-12 min) for producing 2nd generation bioethanol [Kaparaju, P., Serrano, M., Thomsen, A.B., Kongjan, P., Angelidaki, I., 2009. Bioethanol, biohydrogen and biogas production from wheat straw in a biorefinery concept. Bioresource Technology 100 (9), 2562-2568]. Results from batch assays showed that hydrolysate had a methane potential of 384 ml/g-volatile solids (VS)(added). Process performance in CTSR and UASB reactors was investigated by varying hydrolysate concentration and/or organic loading rate (OLR). In CSTR, methane yields increased with increase in hydrolysate concentration and maximum yield of 297 ml/g-COD was obtained at an OLR of 1.9 g-COD/l d and 100% (v/v) hydrolysate. On the other hand, process performance and methane yields in UASB were affected by OLR and/or substrate concentration. Maximum methane yields of 267 ml/g-COD (COD removal of 72%) was obtained in UASB reactor when operated at an OLR of 2.8 g-COD/l d but with only 10% (v/v) hydrolysate. However, co-digestion of hydrolysate with pig manure (1:3 v/v ratio) improved the process performance and resulted in methane yield of 219 ml/g-COD (COD removal of 72%). Thus, anaerobic digestion of hydrolysate for biogas production was feasible in both CSTR and UASB reactor types. However, biogas process was affected by the reactor type and operating conditions. PMID:19647428

Kaparaju, Prasad; Serrano, María; Angelidaki, Irini

2009-12-01

138

Ethanol production by Saccharomyces cerevisiae in biofilm reactors.  

PubMed

Biofilms are natural forms of cell immobilization in which microorganisms attach to solid supports. At ISU, we have developed plastic composite-supports (PCS) (agricultural material (soybean hulls or oat hulls), complex nutrients, and polypropylene) which stimulate biofilm formation and which supply nutrients to the attached microorganisms. Various PCS blends were initially evaluated in repeated-batch culture-tube fermentation with Saccharomyces cerevisiae (ATCC 24859) in low organic nitrogen medium. The selected PCS (40% soybean hull, 5% soybean flour, 5% yeast extract-salt and 50% polypropylene) was then used in continuous and repeated-batch fermentation in various media containing lowered nitrogen content with selected PCS. During continuous fermentation, S. cerevisiae demonstrated two to 10 times higher ethanol production in PCS bioreactors than polypropylene-alone support (PPS) control. S. cerevisiae produced 30 g L-1 ethanol on PCS with ammonium sulfate medium in repeated batch fermentation, whereas PPS-control produced 5 g L-1 ethanol. Overall, increased productivity in low cost medium can be achieved beyond conventional fermentations using this novel bioreactor design. PMID:9439005

Demirci, A; Pometto, A L; Ho, K L

1997-10-01

139

A two-stage enzymatic ethanol-based biodiesel production in a packed bed reactor.  

PubMed

A two-stage enzymatic process for producing fatty acid ethyl ester (FAEE) in a packed bed reactor is reported. The process uses an experimental immobilized lipase (NS 88001) and Novozym 435 to catalyze transesterification (first stage) and esterification (second stage), respectively. Both stages were conducted in a simulated series of reactors by repeatedly passing the reaction mixture through a single reactor, with separation of the by-product glycerol and water between passes in the first and second stages, respectively. The second stage brought the major components of biodiesel to 'in-spec' levels according to the European biodiesel specifications for methanol-based biodiesel. The highest overall productivity achieved in the first stage was 2.52 kg FAEE(kg catalyst)?¹ h?¹ at a superficial velocity of 7.6 cm min?¹, close to the efficiency of a stirred tank reactor under similar conditions. The overall productivity of the proposed two-stage process was 1.56 kg FAEE(kg catalyst)?¹ h?¹. Based on this process model, the challenges of scale-up have been addressed and potential continuous process options have been proposed. PMID:22728395

Xu, Yuan; Nordblad, Mathias; Woodley, John M

2012-12-31

140

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

SciTech Connect

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.

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

2010-01-01

141

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

SciTech Connect

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)

Messenger, S. J. [Massachusetts Inst. of Technology, 77 Massachusetts Ave., 54-1717, Cambridge, MA 02139 (United States); Forsberg, C. [Massachusetts Inst. of Technology, 77 Massachusetts Ave., 24-207, Cambridge, MA 02139 (United States); Massie, M. [Massachusetts Inst. of Technology, 77 Massachusetts Ave., NW12-230, Cambridge, MA 02139 (United States)

2012-07-01

142

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

SciTech Connect

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)

Endo, H. [Toshiba Corporation (Japan); Sawada, T.; Ninokata, H. [Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8550 (Japan)

2002-07-01

143

Fracture mechanics and full scale pipe break testing for the Department of Environment's New Production Reactor-Heavy Water Reactor  

NASA Astrophysics Data System (ADS)

Oak Ridge National Laboratory (ORNL) is completing a major task for the Department of Energy (DOE) in the demonstration that the primary piping of the New Production Heavy Water Reactor (NPR-HWR), with its relatively moderate temperature and pressure, should not suffer an instantaneous Double-Ended-Guillotine-Break (DEGB) under design basis loadings and conditions. The growth of possible small preexisting defects in the piping wall was estimated over a plant life of 60 years. This worst case flaw was then evaluated using fracture mechanics methods. J estimation methods and tearing instability approximations used in this analysis are discussed in this paper. It was established that this worst case flaw would increase in size by at least 14 times before pipe instability during an earthquake would even begin to be possible. The fatigue crack growth analysis is discussed in this paper.

Poole, A. B.

144

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

PubMed

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

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

2014-07-01

145

Vertical high-speed rotating disk reactors for production scale MOVPE of compound semiconductors  

NASA Astrophysics Data System (ADS)

Compound semiconductors are at the heart of todays advanced digital and optoelectronic devices. As device production levels increase, so too does the need for high throughput deposition systems. The vertical rotating disk reactor (RDR) has been scaled to dimensions allowing metal organic chemical vapor deposition (MOCVD) on multiple substrates located on a 300 mm diameter platter. This symmetric large area reactor affords easy access over a wide range of angles for optical monitoring and control of the growth process. The RDR can be numerically modeled in a straightforward manner, and we have derived scaling rules allowing the prediction of optimum process conditions for larger reactor sizes. The material results give excellent agreement with the modeling, demonstrating GaAs/AlAs structures with < +/- 0.9% thickness uniformities on up to 17-50 mm or 4-100 mm GaAs substrates. Process issues related to reactor scaling are reviewed. With high reactant efficiencies and short cycle times between growths, through the use of a vacuum loadlock, the costs per wafer are found to be dramatically less than in alternative process reactors. The high reactant utilization, in combination with a dedicated and highly efficient exhaust scrubbing system, minimizes the systems environmental impact.

Walker, Robert C.; Thompson, Alan G.; Tompa, Gary S.; Zawadzki, Peter A.; Gurary, Alexander

1994-10-01

146

Degradation of organic compounds and production of activated species in Dielectric Barrier Discharges and Glidarc reactors  

E-print Network

Major sterilization mechanisms are related to atoms and radicals, charged parti-cles, excited molecules, ozone, and UV radiation. The ROS (Reactive Oxygen Species) are well known as evildoers. These species are easily created in ambient air and water and they live long enough to reach the cell and attack the organic matter. Test molecules conversion in dry and wet air is studied using Dielectric Barrier Discharge (DBD) and Gliding Arc Reactors (GAR). The effects of tem-perature and energy deposition into the media on the active species production and then on the organic compounds degradation are presented for two non thermal plasma reactors: DBD and GAR. Main production species investigated are OH, O3, NOx, CO and CxHyOz by-products. It is shown from experiment analysis that the reactive species production is quite different from one reactor to another. GAR and pulsed DBD are two chemical processing ways in which the temperature of heavy species in ionized gas is determinant. By reviewing the species producti...

Cormier, Jean Marie; Khacef, Ahmed

2008-01-01

147

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

SciTech Connect

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).

Not Available

1990-06-20

148

[Hydrolyzed lactose contained in the ultrafiltrate of milk or milk products in an enzymatic membrane reactor].  

PubMed

Milk and milk by-products with a low lactose content, very interesting from a nutritional and technological point of view, were obtained by the application of the enzymatic membrane reactor technique. A previous separation of the aqueous phase of milk or ultrafiltrate was necessary and realized by ultrafiltration. The enzyme, a commercial beta-galactosidase, was maintained in solution in the retentate part of the membrane reactor. The optimal conditions of the lactose hydrolysis in milk and whey ultrafiltrates were determined. The behaviour of the aqueous phase of milk in membrane reactor, specially of mineral salts, was studied. Three possibilities were proposed to avoid a calcium-phosphate deposit on the surface of (and in) the reactor membranes: a precipitation of calcium salts by heating, a partial demineralization by electrodialysis or ion exchange, a calcium complexation by addition of sodium citrate. A continuous process for the lactose hydrolysis of milk and demineralized whey or milk ultrafiltrate was proposed. The organoleptic quality of low lactose milk, before and after heat treatment, was evaluated by a tasting panel. High sweeting syrup, were obtained by concentration of lactose hydrolyzed and demineralized ultrafiltrates. Nutritional aspects of these products are discussed specially from the toxicological point of view of galactose. PMID:101122

Roger, L; Maubois, J L; Thapon, J L; Brule, G

1978-01-01

149

Production of l-DOPA using Cu-alginate gel immobilized tyrosinase in a batch and packed bed reactor  

Microsoft Academic Search

In this study, production of l-DOPA (l-3, 4-dihydroxy phenylalanine) was investigated by using tyrosinase enzyme in batch and packed bed reactors. Tyrosinase has been immobilized with method of entrapment in copper-alginate gels. l-DOPA concentration obtained from batch reactor for free and immobilized enzyme was 9.5 and 4.5mg\\/L, respectively. l-DOPA concentration was obtained as 1.2mg\\/L in the packed bed reactor. When

Selma Ates; Esra Cortenlioglu; Emine Bayraktar; Ulku Mehmetoglu

2007-01-01

150

Response of structures to energetic events for the Savannah River Site production reactors probabilistic risk assessment  

SciTech Connect

The response of structures to energetic events postulated to arise in a probabilistic risk assessment (PRA) of a Savannah River Site (SRS) production reactor is addressed. Energetic events that arise in PRAs can damage structures and therefore have a significant influence on subsequent accident progression. Consequently, the structural response is important to the calculated risk of operating a plant. Difficulties are encountered, however, in the analysis of structural response of components to energetic loadings. First, the analysis of energetic events often does not provide well-defined static or dynamic loads acting on the structures. Secondly, risk assessments, by their nature, address a wide range of events that are not necessarily precisely defined. This paper describes an approach taken to develop the structural analysis required to support the PRA of the SRS production reactor, that overcomes these difficulties.

Santa Cruz, S.M.; Smith, D.C. [Science Applications International Corp., Albuquerque, NM (United States); Yau, W.F. [Westinghouse Savannah River Co., Aiken, SC (United States)

1992-10-01

151

Response of structures to energetic events for the Savannah River Site production reactors probabilistic risk assessment  

SciTech Connect

The response of structures to energetic events postulated to arise in a probabilistic risk assessment (PRA) of a Savannah River Site (SRS) production reactor is addressed. Energetic events that arise in PRAs can damage structures and therefore have a significant influence on subsequent accident progression. Consequently, the structural response is important to the calculated risk of operating a plant. Difficulties are encountered, however, in the analysis of structural response of components to energetic loadings. First, the analysis of energetic events often does not provide well-defined static or dynamic loads acting on the structures. Secondly, risk assessments, by their nature, address a wide range of events that are not necessarily precisely defined. This paper describes an approach taken to develop the structural analysis required to support the PRA of the SRS production reactor, that overcomes these difficulties.

Santa Cruz, S.M.; Smith, D.C. (Science Applications International Corp., Albuquerque, NM (United States)); Yau, W.F. (Westinghouse Savannah River Co., Aiken, SC (United States))

1992-01-01

152

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

PubMed Central

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

2012-01-01

153

Health physics considerations in 131I production at a one megawatt TRIGA reactor  

E-print Network

Physics Considerations in "'I Production at a One Megawatt TRIGA Reactor. (August 1993) Jason Todd Flora, B. S, Purdue University Chair of Advisory Committee: Dr. Milton E. McLain The Nuclear Science Center can effectively produce '"I by thermal... family has greatly enhanced my career and life. ACKNOWLEDGMENTS The Nuclear Engineering Department of Texas A&M University is the best educational department that 1 have been associated with. The assistance of the staff ha allowed me to advance my...

Flora, Jason Todd

2012-06-07

154

Mass spectrometric measurements of fission product effusion from irradiated light water reactor fuel  

SciTech Connect

Laboratory measurements of fission products effusion from irradiated light water reactor fuels are being carried out at the Joint Research Centre (JRC) of the European Commission in Karlsruhe. The aim of these experiments is twofold: first, data are obtained on diffusion of gaseous and less volatile fission products, which are suitable for a mechanistic analysis of their migration processes in the fuel; second, the measured vaporization rate of the various species makes it possible to check the thermodynamic models of the system fuel + fission products, used to predict the chemical reactions occurring during reactor accidents and, hence, the state of the radiotoxical nuclides released. Here, irradiated light water reactor fuel from the BR3 reactor was thermally annealed up to 2,500 K in a Knudsen cell, and the effusing vapors were measured by mass spectrometry. The experiments provide data on the stoichiometry evolution of the fuel during release as well as a reliable method to evaluate the diffusion coefficients of volatile and less-volatile fission products. The analysis of the data starts from diffusion of xenon, which clearly shows three typical release stages respectively controlled by radiation damage annealing, self-diffusion, and matrix vaporization. The experimental measurements are also in agreement with the predictions of intragranular trapping models. Barium and cesium showed faster release than xenon, the former being likely to diffuse atomically to the grain boundaries where no evidence of formation of stable zirconates was found. These results were compared with those obtained by a burnup-simulated fuel, where barium was initially present in a perovskite phase, producing essentially different release patterns.

Capone, F.; Hiernaut, J.P.; Martellenghi, M.; Ronchi, C. [European Commission, Karlsruhe (Germany). European Inst. for Transuranium Elements

1996-11-01

155

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

Microsoft Academic Search

This study presents the analyses of the fissile breeding and long-lived fission product (LLFP) transmutation potentials of\\u000a PROMETHEUS reactor. For this purpose, a fissile breeding zone (FBZ) fueled with the ceramic uranium mono-carbide (UC) and\\u000a 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

Hüseyin Yap?c?; Gül?ah Öz???k

2008-01-01

156

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

SciTech Connect

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)

Jaroszewicz, J.; Pytel, K.; Dabkowski, L.; Krzysztoszek, G. [Institute of Atomic Energy, 05-400 Otwock-Swierk (Poland)

2008-07-15

157

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

SciTech Connect

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.

Nghiem, N.P.; Davison, B.H. [Oak Ridge National Lab., TN (United States); Sun, M.Y.; Bienkowski, P.R. [Univ. of Tennessee, Knoxville, TN (United States)

1997-12-31

158

Production of polygalacturonases by Aspergillus section Nigri strains in a fixed bed reactor.  

PubMed

Polygalacturonases (PG) are pectinolytic enzymes that have technological, functional and biological applications in food processing, fruit ripening and plant-fungus interactions, respectively. In the present, a microtitre plate methodology was used for rapid screening of 61 isolates of fungi from Aspergillus section Nigri to assess production of endo- and exo-PG. Studies of scale-up were carried out in a fixed bed reactor operated under different parameters using the best producer strain immobilised in orange peels. Four experiments were conducted under the following conditions: the immobilised cells without aeration; immobilised cells with aeration; immobilised cells with aeration and added pectin; and free cells with aeration. The fermentation was performed for 168 h with removal of sample every 24 h. Aspergillus niger strain URM 5162 showed the highest PG production. The results obtained indicated that the maximum endo- and exo-PG activities (1.18 U ? mL-1 and 4.11 U ? mL-1, respectively) were obtained when the reactor was operating without aeration. The microtitre plate method is a simple way to screen fungal isolates for PG activity detection. The fixed bed reactor with orange peel support and using A. niger URM 5162 is a promising process for PG production at the industrial level. PMID:23358324

Maciel, Marília; Ottoni, Cristiane; Santos, Cledir; Lima, Nelson; Moreira, Keila; Souza-Motta, Cristina

2013-01-01

159

Continuous enzymatic transesterification of high oleic sunflower oil in a packed bed reactor: influence of the glycerol production  

Microsoft Academic Search

The transesterification of high oleic sunflower oil with butanol by the immobilized Lipozyme® in n-hexane was carried out in a continuous packed bed reactor, oleic acid, butyl ester, and glycerol being formed as the main products. It was found that glycerol, insoluble in n-hexane, remained in the reactor adsorbed onto the enzymatic support, leading to a drastic decrease in enzymatic

Valérie Dossat; Didier Combes; Alain Marty

1999-01-01

160

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

SciTech Connect

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%.

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

2008-08-01

161

Hydrogen production from rice winery wastewater in an upflow anaerobic reactor by using mixed anaerobic cultures  

Microsoft Academic Search

Continuous production of hydrogen from the anaerobic acidogenesis of a high-strength rice winery wastewater by a mixed bacterial flora was demonstrated. The experiment was conducted in a 3.0-l upflow reactor to investigate individual effects of hydraulic retention time (HRT) (2–24h), chemical oxygen demand (COD) concentration in wastewater (14–36g COD\\/l), pH (4.5–6.0) and temperature (20–55°C) on bio-hydrogen production from the wastewater.

Hanqing Yu; Zhenhu Zhu; Wenrong Hu; Haisheng Zhang

2002-01-01

162

Experiments and analysis of fission product release in HEU-fuelled SLOWPOKE-2 reactors  

NASA Astrophysics Data System (ADS)

Fission product activity levels have been measured using a transportable gamma ray spectroscopy system at four SLOWPOKE-2 facilities. Through an analysis of the concentrations of these radionuclides in samples of the reactor coolant and gas headspace, the rate of release from the fuel has been determined by a Savitzky-Golay method and also by a non-linear least squares method. The release rate calculation has been validated against the mainframe code SUMRT. By examining the release rates, the source of the short-lived fission products is determined to be direct recoil from exposed uranium-bearing surfaces.

Harnden-Gillis, A. C.; Bennett, L. G. I.; Lewis, B. J.

1994-07-01

163

Production of Gadolinium-loaded Liquid Scintillator for the Daya Bay Reactor Neutrino Experiment  

E-print Network

We report on the production and characterization of liquid scintillators for the detection of electron antineutrinos by the Daya Bay Reactor Neutrino Experiment. One hundred eighty-five tons of gadolinium-loaded (0.1% by mass) liquid scintillator (Gd-LS) and two hundred tons of unloaded liquid scintillator (LS) were successfully produced from a linear-alkylbenzene (LAB) solvent in six months. The scintillator properties, the production and purification systems, and the quality assurance and control (QA/QC) procedures are described.

Wanda Beriguete; Jun Cao; Yayun Ding; Sunej Hans; Karsten M. Heeger; Liangming Hu; Aizhong Huang; Kam-Biu Luk; Igor Nemchenok; Ming Qi; Richard Rosero; Hansheng Sun; Ruiguang Wang; Yifang Wang; Liangjian Wen; Yi Yang; Minfang Yeh; Zhiyong Zhang; Li Zhou

2014-02-27

164

Migration behavior of fission products in and from spherical high-temperature reactor fuel elements  

SciTech Connect

Diffusion behavior of some metallic fission products in high-temperature reactor fuel elements, which had been irradiated in an in-pile gas loop (Saphir) installed in the Pegase reactor (France), was studied. Diffusion coefficients of cesium and silver in hightemperature isotropic pyrolytic carbon and graphite matrix under in-pile conditions were obtained by analyzing the concentration profiles of the fission products in the fuel elements, which had been measured by postirradiation examination. Although ruthenium profiles were measured, analysis of the diffusion coefficients could not be carried out because of the virtually flat distributions. By comparing the concentrations of the cesium isotopes in the fuel-free zone of the elements, it was found that TUCs behaved anomalously in the graphite matrix, which was, probably, caused by activation of an undetectable amount of TTCs impurity involved in the matrix. For the extremely high concentration of these fission products, which had been observed near the surface of the element, two causes, the uranium contamination concentrating there and the trapping effect in the defects introduced by fission of the locally concentrated uranium, were considered, although these high concentrations of the fission products were neglected in the analysis. Furthermore, Transport behavior of the fission products through the gas gap from the fuel element to the graphite tube containing the elements was studied by measuring the concentration profiles in the tube. It was concluded that ruthenium transport occurred by direct fission recoil from the surface uranium contamination, whereas that of cesium, by desorption from the surface.

Fukuda, K.; Groos, E.; Rau, J.

1985-06-01

165

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

SciTech Connect

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.

White, L.S.

1990-07-01

166

Innovative self-powered submersible microbial electrolysis cell (SMEC) for biohydrogen production from anaerobic reactors.  

PubMed

A self-powered submersible microbial electrolysis cell (SMEC), in which a specially designed anode chamber and external electricity supply were not needed, was developed for in situ biohydrogen production from anaerobic reactors. In batch experiments, the hydrogen production rate reached 17.8 mL/L/d at the initial acetate concentration of 410 mg/L (5 mM), while the cathodic hydrogen recovery ( [Formula: see text] ) and overall systemic coulombic efficiency (CE(os)) were 93% and 28%, respectively, and the systemic hydrogen yield ( [Formula: see text] ) peaked at 1.27 mol-H(2)/mol-acetate. The hydrogen production increased along with acetate and buffer concentration. The highest hydrogen production rate of 32.2 mL/L/d and [Formula: see text] of 1.43 mol-H(2)/mol-acetate were achieved at 1640 mg/L (20 mM) acetate and 100 mM phosphate buffer. Further evaluation of the reactor under single electricity-generating or hydrogen-producing mode indicated that further improvement of voltage output and reduction of electron losses were essential for efficient hydrogen generation. In addition, alternate exchanging the electricity-assisting and hydrogen-producing function between the two cell units of the SMEC was found to be an effective approach to inhibit methanogens. Furthermore, 16S rRNA genes analysis showed that this special operation strategy resulted same microbial community structures in the anodic biofilms of the two cell units. The simple, compact and in situ applicable SMEC offers new opportunities for reactor design for a microbial electricity-assisted biohydrogen production system. PMID:22402271

Zhang, Yifeng; Angelidaki, Irini

2012-05-15

167

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

PubMed

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

Fontana, Roselei Claudete; da Silveira, Maurício Moura

2012-11-01

168

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

PubMed

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

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

2013-06-01

169

Inulinase production in a packed bed reactor by solid state fermentation.  

PubMed

In this work, production of inulinase was carried out in a packed bed reactor (PBR) under solid state fermentation. Kluyveromyces marxianus var. marxianus was used to produce the inulinase using pressmud as substrate. The parameters like air flow rate, packing density and particle size were optimized using response surface methodology (RSM) to maximize the inulinase production. The optimum conditions for the maximum inulinase production were: air flow rate - 0.82 L/min, packing density - 40 g/L and particle size - 0.0044 mm (mesh - 14/20). At these optimized conditions, the production of inulinase was found to be 300.5 unit/gram of dry substrate (U/gds). PMID:23688470

Dilipkumar, M; Rajamohan, N; Rajasimman, M

2013-07-01

170

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

NASA Astrophysics Data System (ADS)

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.

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

171

Polyunsaturated fatty acids production with a solid-state column reactor.  

PubMed

To investigate the potential production of polyunsaturated fatty acids (PUFAs), a solid-state column reactor of rice bran with Mortierella alpina was used. The optimal conditions for PUFAs production were rice bran supplementation with 3.75% (ww(-1)) nitrogen source at initial moisture content 57%, initial pH 6-7, aeration, and incubation at 20 degrees C for 5 days and then at 12 degrees C for 7 days. Each gram of substrate carbon yielded 127 mg of total PUFAs, 12 mg of eicosapentaenoic acid (EPA), 6 mg of arachidonic acid (AA), 5mg of alpha-linolenic acid (ALA), and 117 mg of linoleic acid (LA) after 12 days incubation. Aeration enhanced the productions of AA, EPA, and total PUFAs. Supplementation of the nitrogen source on the fourth day and then a shift to lower temperature on the fifth day increased EPA production. PMID:18230414

Jang, Hung-Der; Yang, Shang-Shyng

2008-09-01

172

Uncertainty Analysis on Fission Molybdenum Production with a Nuclear Fuel Target in a Research Reactor  

SciTech Connect

The use of a low-enriched uranium (LEU) fuel target was examined for the feasibility of {sup 99}Mo production in a High-flux Advanced Neutron Application Reactor (HANARO). Uncertainty analysis was done with respect to the {sup 99}Mo yield ratio, {sup 239}Pu yield ratio, annual production rate, and decontamination requirement. Validity of a coupled code system, MCNP/ORIGEN2, was evaluated to estimate reliable isotopic number densities after irradiation and cooling. An equilibrium core model for the MCNP fixed-source problem was found by the reactor design methodology known as WIMS/VENTURE. Optimized target design options were proposed for both the LEU and highly enriched uranium (HEU) targets. Variables related to the target fabrication process and reactor physics condition were considered as uncertainty-inducing parameters. The most important factor affecting the overall uncertainty of the LEU option was the engineering tolerances achievable in the fabrication process of fuel film. The LEU has twice the uncertainty of HEU under current technology, which makes the economics of LEU worse than HEU. It is acceptable, however, in view of the radioactive purity of the alpha emitter because the uncertainty of the impurity level of {sup 239}Pu is expected to be relatively small - only 6.5% with a 95% confidence level.

Cho, Dong-Keun; Kim, Myung-Hyun [Kyung Hee University (Korea, Republic of)

2003-10-15

173

Production of electron neutrinos at nuclear power reactors and the prospects for neutrino physics  

SciTech Connect

High flux of electron neutrinos({nu}{sub e}) is produced at nuclear power reactors through the decays of nuclei activated by neutron capture. Realistic simulation studies on the neutron transport and capture at the reactor core were performed. The production of {sup 51}Cr and {sup 55}Fe give rise to monoenergetic {nu}{sub e}'s at Q-values of 753 keV and 231 keV and fluxes of 8.3x10{sup -4} and 3.0x10{sup -4}{nu}{sub e}/fission, respectively. Using data from a germanium detector at the Kuo-Sheng Power Plant, we derived direct limits on the {nu}{sub e} magnetic moment and the radiative lifetime of {mu}{sub {nu}}<1.3x10{sup -8}{mu}{sub B} and {tau}{sub {nu}}/m{sub {nu}}>0.11 s/eV at 90% confidence level (CL), respectively. Indirect bounds on {tau}{sub {nu}}/m{sub {nu}}{sup 3} were also inferred. The {nu}{sub e}-flux can be enhanced by loading selected isotopes to the reactor core, and the potential applications and achievable statistical accuracies were examined. These include accurate cross-section measurements, studies of mixing angle {theta}{sub 13} and monitoring of plutonium production.

Xin, B. [Department of Nuclear Physics, Institute of Atomic Energy, Beijing 102413 (China); Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Wong, H.T.; Chen, C.P.; Li, H.B.; Lee, F.S.; Lin, S.T.; Singh, V.; Wu, S.C. [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Chang, C.Y. [Institute of Physics, Academia Sinica, Taipei 115 (China); Department of Physics, University of Maryland, College Park Maryland 20742 (United States); Li, J.; Yue, Q. [Institute of High Energy Physics, Chinese Academy of Science, Beijing 100039 (China); Department of Engineering Physics, Tsing Hua University, Beijing 100084 (China); Vannucci, F. [LPNHE, Universite de Paris VII, Paris 75252 (France); Zhou, Z. Y. [Department of Nuclear Physics, Institute of Atomic Energy, Beijing 102413 (China)

2005-07-01

174

Low enriched uranium foil plate target for the production of fission Molybdenum99 in Pakistan Research Reactor1  

Microsoft Academic Search

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

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

2009-01-01

175

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

NASA Technical Reports Server (NTRS)

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.

Sibille, Laurent; Dominques, Jesus A.

2012-01-01

176

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

SciTech Connect

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)

Bsebsu, F.M.; Abotweirat, F. [Reactor Department, Renewable Energies and Water Desalination Research Cente, P.O. Box 30878 Tajoura, Tripoli (Libyan Arab Jamahiriya)], E-mail: Bsebso@yahoo.com, E-mail: abutweirat@yahoo.com; Elwaer, S. [Radiochemistry Department, Renewable Energies and Water Desalination Research Cente, P.O. Box 30878 Tajoura, Tripoli (Libyan Arab Jamahiriya)], E-mail: samiwer@yahoo.com

2008-07-15

177

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

PubMed Central

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

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

2009-01-01

178

Ammonium recovery from reject water combined with hydrogen production in a bioelectrochemical reactor.  

PubMed

In this study, a bioelectrochemical reactor was investigated for simultaneous hydrogen production and ammonium recovery from reject water, which is an ammonium-rich side-stream produced from sludge treatment processes at wastewater treatment plants. In the anode chamber of the reactor, microorganisms converted organic material into electrical current. The electrical current was used to generate hydrogen gas at the cathode with 96±6% efficiency. Real or synthetic reject water was fed to the cathode chamber where proton reduction into hydrogen gas resulted in a pH increase which led to ammonium being converted into volatile ammonia. The ammonia could be stripped from the solution and recovered in acid. Overall, ammonium recovery efficiencies reached 94% with synthetic reject water and 79% with real reject water. This process could potentially be used to make wastewater treatment plants more resource-efficient and further research is warranted. PMID:23973971

Wu, Xue; Modin, Oskar

2013-10-01

179

Continuous production of Cu2ZnSnS4 nanocrystals in a flow reactor.  

PubMed

A procedure for the continuous production of Cu(2)ZnSnS(4) (CZTS) nanoparticles with controlled composition is presented. CZTS nanoparticles were prepared through the reaction of the metals' amino complexes with elemental sulfur in a continuous-flow reactor at moderate temperatures (300-330 °C). High-resolution transmission electron microscopy and X-ray diffraction analysis showed the nanocrystals to have a crystallographic structure compatible with that of the kesterite. Chemical characterization of the materials showed the presence of the four elements in each individual nanocrystal. Composition control was achieved by adjusting the solution flow rate through the reactor and the proper choice of the nominal precursor concentration within the flowing solution. Single-particle analysis revealed a composition distribution within each sample, which was optimized at the highest synthesis temperatures used. PMID:22211575

Shavel, Alexey; Cadavid, Doris; Ibáñez, Maria; Carrete, Alex; Cabot, Andreu

2012-01-25

180

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

Federal Register 2010, 2011, 2012, 2013

...Commission [Docket No. ER11-4266-000] Richland-Stryker Generation LLC; Supplemental Notice That Initial Market-Based Rate...in the above-referenced proceeding of Richland-Stryker Generation LLC's application for market-based rate authority,...

2011-08-17

181

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

SciTech Connect

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.

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

1998-07-01

182

Directions to scanner McCausland Center, Palmetto Health Richland Memorial Hospital  

E-print Network

Directions to scanner McCausland Center, Palmetto Health Richland Memorial Hospital 6 Medical Park light) � Go through next light (Pedestrian crossing light) � Take next right into Heart Hospital and Outpatient surgery lot. Do not park in assigned doctor spaces. � Enter building on Heart Hospital Side (Left

Almor, Amit

183

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

SciTech Connect

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.

Wright, T.S.

1992-11-01

184

Technology of Controlled Nuclear Fusion (Report on the 2nd Topical Meeting, Richland, 1976)  

Microsoft Academic Search

The main purpose of this second topical meeting, which was organized by the American Nuclear Society and its Richland Section and co-sponsored by the US Energy Research and Development Administration and the Electric Power Research Institute (EPRI), was to review and assess controlled nuclear fusion technological developments in the past two and a half years since the first topical meeting

G. R. Hopkins

1977-01-01

185

The Hanford Site Richland Operations Office Office of River Protection Office of Science  

E-print Network

The Hanford Site Richland Operations Office Office of River Protection Office of Science Plateau) Construction Contractor www.hanford.gov Mission Support Contractor River Corridor Contractor #12.sieracki@rl.doe.gov Web Site: www.hanford.gov/rl Office of River Protection Susan C. Johnson Small Business Program

186

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

SciTech Connect

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.

Orlov, Andrey [Paul Scherrer Institut, Villigen (Switzerland); Degueldre, Claude, E-mail: claude.degueldre@psi.ch [Paul Scherrer Institut, Villigen (Switzerland); Kaufmann, Wilfried [Kernkraftwerk Leibstadt, Leibstadt (Switzerland)

2013-01-15

187

Production of tomato flavor volatiles from a crude enzyme preparation using a hollow-fiber reactor.  

PubMed

In recent years there has been an increase in the interest in the production of compounds by isolation from natural sources or through processes that can be deemed "natural". This is of particular interest in the food and beverage industry for flavors and aromas. Hexanal, organoleptically known to possess "green character", is of considerable commercial interest. The objective of this study was to determine if the enzyme template known to be responsible for the synthesis of hexanal from linoleic acid (18:2) in tomato fruits could be harnessed using a hollow-fiber reactor. A hollow-fiber reactor system was set up and consisted of a XAMPLER ultrafiltration module coupled to a reservoir. The enzyme template was extracted from ripe tomato fruits and processed through an ultrafiltration unit (NMWC of 100 kDa) to produce a retentate enriched in soluble and membrane-associated lipoxygenase (LOX) and hydroperoxide lyase (HPL). This extract was recirculated through the lumen of the hollow-fiber ultrafiltration unit with the addition of substrate in the form of linoleic acid, with buffer addition to the reaction flask to maintain a constant retentate volume. Product formation was measured in the permeate using solid phase microextraction (SPME) developed for this system. At exogenous substrate concentrations of 16 mM and a transmembrane pressure of 70 kPa, hexanal production rates are in the order of 5.1 microg/min. Addition of Triton X-100 resulted in membrane fouling and reduced flux. The reactor system has been run for periods of up to 1 week and has been shown to be stable over this period. PMID:10620268

Cass, B J; Schade, F; Robinson, C W; Thompson, J E; Legge, R L

2000-02-01

188

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

NASA Astrophysics Data System (ADS)

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.

Fukushima, Kimichika; Ogawa, Takashi

189

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

SciTech Connect

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.

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

1988-01-01

190

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

SciTech Connect

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.

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

2013-10-01

191

The Oklo natural reactor: Cumulative fission yields and retentivity of the symmetric mass region fission products  

NASA Astrophysics Data System (ADS)

Solid source mass spectrometry has been used to determine the relative cumulative fission yields of five elements in three samples of uranium ore from reactor zones in the Oklo mine site. Eighteen fission chains covering the mass range from 105 ? A ? 130 have been measured for Pd, Ag, Cd, Sn and Te. These measurements have enabled a number of nuclear parameters to be calculated including the relative proportions of 235U, 238U and 239Pu involved in the fission process. The concentration of the five elements in the Oklo samples have also been measured using the stable isotope dilution technique. These values have then been compared to the estimates of the amount of these elements produced by fission under the conditions that are appropriate to the three samples. This procedure enables the retentivity of the elements in the reactor zones to be evaluated. Our work confirms the fact that Pd and Te are retained almost in their entirety in the samples, whereas the other three elements have been partially lost from the reactor site. Almost all the Cd fission products have been lost, and more than 50% of the Ag and Sn fission-produced material has been removed.

De Laeter, J. R.; Rosman, K. J. R.; Smith, C. L.

1980-10-01

192

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

SciTech Connect

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.

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

193

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

DOEpatents

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.

Balachandran, Uthamalingam (Hinsdale, IL); Dusek, Joseph T. (Lombard, IL); Kleefisch, Mark S. (Napersville, IL); Kobylinski, Thadeus P. (Lisle, IL)

1996-01-01

194

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

DOEpatents

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.

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

1996-11-12

195

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

SciTech Connect

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.

Dawn M. Scates; John (Jack) K. Hartwell; John b. Walter

2010-10-01

196

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

SciTech Connect

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.

Dawn M. Scates; John (Jack) K Hartwell; John B. Walter

2008-09-01

197

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

SciTech Connect

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.

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

2008-09-30

198

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

DOEpatents

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.

Paulson, L.E.

1988-05-13

199

Modelling and simulation of 1,2-dichloroethane production by ethylene oxychlorination in fluidized-bed reactor  

Microsoft Academic Search

A comprehensive reactor model for ethylene oxychlorination for the production of 1,2-dichloroethane in a fluidized-bed reactor is developed. The model is based on the two-phase theory of fluidization and allows for the change in volumetric gas flow rate in the dense phase due to the change in number of moles accompanying the reaction. The model predictions compared favorably with the

S. M. Al-Zahrani; A. M. Aljodai; K. M. Wagialla

2001-01-01

200

Transmutation of high-level radioactive waste and production of {sup 233}U using an accelerator-driven reactor  

SciTech Connect

Reactor safety, the disposal of high-level nuclear waste, and nonproliferation of nuclear material for military purposes are the problems of greatest concern for nuclear energy. Technologies for accelerators developed in the field of high-energy physics can contribute to solving these problems. For reactor safety, especially for that of a Na-cooled fast reactor, the use of an accelerator, even a small one, can enhance the safety using a slightly subcritical reactor. There is growing concern about how we can deal with weapons-grade Pu, and about the large amount of Pu accumulating from the operation of commercial reactors. It has been suggested that this Pu could be incinerated, using the reactor and a proton accelerator. However, because Pu is a very valuable material with future potential for generating nuclear energy, we should consider transforming it into a proliferation-resistant material that cannot be used for making bombs, rather than simply eliminating the Pu. An accelerator-driven fast reactor (700 MWt), run in a subcritical condition, and fueled with MOX can generate {sup 233}U more safely and efficiently than can a critical reactor. We evaluate the production of {sup 233}U, {sup 239}Pu, and the transmutation of the long-lived fission products of {sup 99}Tc and {sup 129}I, which are loaded with YH{sub 1.7} between the fast core and blanket, by reducing the conversion factor of Pu to {sup 233}U. And we assessed the rates of radiation damage, hydrogen production, and helium production in a target window and in the surrounding vessel.

Takahashi, Hiroshi; Takashita, Hirofumi; Chen, Xinyi

1994-08-01

201

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

SciTech Connect

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.

Lastres, Oscar [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); Chandler, David [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)] [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Jarrell, Joshua J [ORNL] [ORNL; Maldonado, G. Ivan [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK)

2011-01-01

202

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

SciTech Connect

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.

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

2010-10-01

203

Estimate of LOCA-FI plenum pressure uncertainty for a five-ring RELAP5 production reactor model  

SciTech Connect

The RELAP5/MOD2.5 code (RELAP5) is used to perform best-estimate analyses of certain postulated Design Basis Accidents (DBAs) in SRS production reactors. Currently, the most limiting DBA in terms of reactor power level is an instantaneous double-ended guillotine break (DEGB) loss of coolant accident (LOCA). A six-loop RELAP5 K Reactor model is used to analyze the reactor system behavior dozing the Flow Instability (FI) phase of the LOCA, which comprises only the first 5 seconds following the DEGB. The RELAP5 K Reactor model includes tank and plenum nodalizations having five radial rings and six azimuthal sectors. The reactor system analysis provides time-dependent plenum and tank bottom pressures for use as boundary conditions in the FLOWTRAN code, which models a single fuel assembly in detail. RELAP5 also performs the system analysis for the latter phase of the LOCA, denoted the Emergency Cooling System (ECS) phase. Results from the RELAP analysis are used to provide boundary conditions to the FLOWTRAN-TF code, which is an advanced two-phase version of FLOWTRAN. The RELAP5 K Reactor model has been tested for LOCA-FI and Loss-of-Pumping Accident analyses and the results compared with equivalent analyses performed with the TRAC-PF1/MOD1 code (TRAC). An equivalent RELAP5 six-loop, five-ring, six-sector L Reactor model has been benchmarked against qualified single-phase system data from the 1989 L-Area In-Reactor Test Program. The RELAP5 K and L Reactor models have also been subjected to an independent Quality Assurance verification.

Griggs, D.P.

1993-03-01

204

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

SciTech Connect

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.

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

2005-03-10

205

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

SciTech Connect

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.

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

2005-04-01

206

Biodiesel production in a magnetically-stabilized, fluidized bed reactor with an immobilized lipase in magnetic chitosan microspheres.  

PubMed

Biodiesel production by immobilized Rhizopus oryzae lipase in magnetic chitosan microspheres (MCMs) was carried out using soybean oil and methanol in a magnetically-stabilized, fluidized bed reactor (MSFBR). The maximum content of methyl ester in the reaction mixture reached 91.3 (w/v) at a fluid flow rate of 25 ml/min and a magnetic field intensity of 150 Oe. In addition, the MCMs-immobilized lipase in the reactor showed excellent reusability, retaining 82 % productivity even after six batches, which was much better than that in a conventional fluidized bed reactor. These results suggested that a MSFRB using MCMs-immobilized lipase is a promising method for biodiesel production. PMID:24062133

Zhou, Gui-Xiong; Chen, Guan-Yi; Yan, Bei-Bei

2014-01-01

207

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

NASA Astrophysics Data System (ADS)

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.

Yap?c?, Hüseyin; Öz???k, Gül?ah

2008-12-01

208

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

NASA Technical Reports Server (NTRS)

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.

Povitsky, Alex; Salas, Manuel D.

2001-01-01

209

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

SciTech Connect

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.

Vigerstad, T J

1980-01-01

210

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

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

211

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

SciTech Connect

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.

Miller, R.B.; Johnson, T.E.; Santner, C.R. [M.W. Kellogg Co., Houston, TX (United States); Avidan, A.A.; Johnson, D.L. [Mobil Research and Development Corp., Paulsboro, NJ (United States)

1995-09-01

212

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

SciTech Connect

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.

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

1991-12-31

213

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

SciTech Connect

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.

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

1991-01-01

214

Performance of a cutinase membrane reactor for the production of biodiesel in organic media.  

PubMed

The enzymatic transesterification of oils with an alcohol, using recombinant cutinase of Fusarium solani pisi microencapsulated in sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane reversed micelles, was performed in a membrane bioreactor (MBR). A tubular ceramic membrane with a nominal molecular weight cut off of 15,000 Da was used to retain the enzyme, and characterized in terms of rejection coefficients of the reaction components by transmission experiments. The performance of the MBR in a total recirculation-batch mode was compared with results obtained in a stirred batch tank reactor. The continuous operation of the MBR was also evaluated and the influence of the alcohol type and permeate flow rate on conversion degree and productivity (up to 500 g(product) /day/g(enzyme) was attained) were analyzed. Cutinase wild type and mutant T179C were tested for this process and the high long-term operational stability of the cutinase mutant demonstrated its potential as biocatalyst for the enzymatic continuous production of biodiesel. PMID:21290382

Badenes, Sara M; Lemos, Francisco; Cabral, Joaquim M S

2011-06-01

215

Positive safety features of US nuclear reactors: technical lessons confirmed at Chernobyl. Hearing before the Subcommittee on Energy Research and Production of the Committee on Science and Technology, US House of Representatives, Ninety-Ninth Congress, Second Session, May 14, 1986, No. 138  

SciTech Connect

Dr. Rudolf Schulten of West Germany and expert witnesses from national laboratories, utilities, and the nuclear industry testified on reactor safety issues as they relate to the Chernobyl accident and public concern that modern technology has not paid enough attention to public safety. Each of the witnesses contributed safety-related information based on what has been learned from the Soviet incident. Particular focus went to similarities and differences between the Chernobyl and US reactors in safety design and engineering and to the environmental effects of the accident. The N reactor near Richland and a commercial reactor at Fort St. Vrain, Colorado are the only two operating graphite reactors, but neither is a boiling water reactor.

Not Available

1986-01-01

216

Theory, design, and operation of liquid metal fast breeder reactors, including operational health physics  

Microsoft Academic Search

A comprehensive evaluation was conducted of the radiation protection practices and programs at prototype LMFBRs with long operational experience. Installations evaluated were the Fast Flux Test Facility (FFTF), Richland, Washington; Experimental Breeder Reactor II (EBR-II), Idaho Falls, Idaho; Prototype Fast Reactor (PFR) Dounreay, Scotland; Phenix, Marcoule, France; and Kompakte Natriumgekuhlte Kernreak Toranlange (KNK II), Karlsruhe, Federal Republic of Germany. The

1985-01-01

217

Oxygen transfer in ferric iron biological production in a packed-bed reactor  

Microsoft Academic Search

In this paper, oxygen transfer in the ferrous iron biooxidation process in a packed-bed reactor is studied. The reactor consists of a polymethyl methacrylate column randomly packed with siliceous stone particles with inlets for liquid medium and air at the bottom from where they flood the reactor. The aim of this work is to determine the parameters that influence the

A Mazuelos; R Romero; I Palencia; F Carranza; F. J Borjas

2002-01-01

218

Fission product monitoring of TRISO coated fuel for the advanced gas reactor-1 experiment  

Microsoft Academic Search

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

Dawn M. Scates; John K. Hartwell; John B. Walter; Mark W. Drigert; Jason M. Harp

2010-01-01

219

Lead-cooled fast reactor use in future equilibrium energy production  

Microsoft Academic Search

The design of a lead cooled fast reactor is discussed. In previous works, general characteristics of future nuclear equilibrium energy utilization have been investigated where the toxic radioactive materials are confined in a nuclear center. Natural uranium and\\/or thorium, are supplied to the center as a fuel fed to fission reactors. All of the actinides are recycled in the reactor.

Hiroshi Sekimoto; V. V. Kuznetsov

1994-01-01

220

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

SciTech Connect

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.

Curtis Smith; Scott Beck; Bill Galyean

2005-09-01

221

Enzymatic packed-bed reactor integrated with glycerol-separating system for solvent-free production of biodiesel fuel  

Microsoft Academic Search

From the viewpoint of process engineering in enzymatic biodiesel production, this paper provides a practical basis for development of the packed-bed reactor (PBR) on a bench scale. A key component of this work is the separation of glycerol byproduct in continuous operation. To facilitate measuring and separating the byproduct, we constructed the PBR integrated with a glycerol-separating system. Methyl ester

Shinji Hama; Sriappareddy Tamalampudi; Ayumi Yoshida; Naoki Tamadani; Nobuyuki Kuratani; Hideo Noda; Hideki Fukuda; Akihiko Kondo

2011-01-01

222

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

ERIC Educational Resources Information Center

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…

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

223

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

SciTech Connect

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:

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

224

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

225

Effect of slurry in cat cracking reactor on product yield and quality  

SciTech Connect

Cracking on microbead zeolitic catalysts is becoming one of the most extensively used processes in petroleum refining. Many paths have been taken in improving the cat cracking process. One of these paths is based on logical application of the principles of physicochemical technology. Feasibility was demonstrated for intensifying the catalytic cracking of vacuum distillate by means of various activating additives, mainly refinery by-products, added to the feed in certain concentrations. By varying the concentration of the additive, the process parameters can be regulated. Of the various parameters, the coke deposition on the catalyst is the most sensitive to the action of additives. We have investigated the possibility of intensifying the cat cracking process by optimizing the quantity of slurry fed to the trapping device of the reactor. It was assumed that the slurry acts in the same manner as additions of products from a different source. In a laboratory unit, we determined the effect of small concentrations of slurry on the material balance in cracking.

Useinova, M.S.; Guseinov, A.M.; Kapustin, V.M. [and others

1994-07-01

226

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

PubMed

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

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

2013-11-01

227

Production of ?-carotene from beet molasses by Blakeslea trispora in stirred-tank and bubble column reactors  

Microsoft Academic Search

The effect of aeration rate and agitation speed on ?-carotene production from molasses by Blakeslea trispora in a stirred-tank fermentor and optimization of the production of the pigment in a bubble column reactor were investigated.\\u000a In addition, a central composite design was employed to determine the maximum ?-carotene concentration at optimum values for\\u000a the process variables (aeration rate, sugar concentration,

Yekta Goksungur; Fani Mantzouridou; Triantafyllos Roukas; Parthena Kotzekidou

2004-01-01

228

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

PubMed

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

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

2009-02-11

229

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

SciTech Connect

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).

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

2010-11-17

230

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

PubMed Central

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

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

2014-01-01

231

Design of an Online, Multispectrometer Fission Product Monitoring System (FPMS) to Support Advanced Gas Reactor (AGR) Fuel Testing and Qualification in the Advanced Test Reactor  

SciTech Connect

The US Department of Energy (DOE) is embarking on a series of tests of tristructural isotropic (TRISO) coated-particle reactor fuel for the advanced gas reactor (AGR). As one part of this fuel development program, a series of eight 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 fission product monitoring 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.

John K. Hartwell

2007-06-01

232

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

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

233

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

SciTech Connect

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.

Charles M Barnes

2008-09-01

234

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

NASA Technical Reports Server (NTRS)

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.

Sibille, Laurent; Dominguez, Jesus A.

2012-01-01

235

Estimation of the uncertainty in TRAC/PF1-MOD1 predictions of production reactor plenum pressures  

SciTech Connect

The TRAC-PF1/MOD1 code (TRAC) is used to perform best-estimate analyses of certain postulated design-basis accidents (DBAs) in Savannah River Site (SRS) production reactors. One of the DBAs analyzed is an instantaneous double-ended guillotine break loss-of-coolant accident (LOCA). The TRAC analysis provides time-dependent plenum and tank bottom pressures for use as boundary conditions in a detailed analysis of a single fuel assembly. The quantification of uncertainty is an important element in determining safe operating power levels for SRS reactors. This motivates the estimation of the uncertainty in using spatial interpolations of the relatively coarse cell-average plenum pressure predictions obtained with TRAC to predict detailed reactor plenum pressure distributions. This result supports the adequacy of the {plus minus}5% plenum pressure uncertainty estimated for LOCA analyses.

Griggs, D.P. (Westinghouse Savannah River Co., Aiken, SC (United States))

1992-01-01

236

Hybrid adsorptive membrane reactor  

NASA Technical Reports Server (NTRS)

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.

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

237

Hybrid adsorptive membrane reactor  

DOEpatents

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.

Tsotsis, Theodore T. (Huntington Beach, CA); Sahimi, Muhammad (Altadena, CA); Fayyaz-Najafi, Babak (Richmond, CA); Harale, Aadesh (Los Angeles, CA); Park, Byoung-Gi (Yeosu, KR); Liu, Paul K. T. (Lafayette Hill, PA)

2011-03-01

238

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

NASA Astrophysics Data System (ADS)

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 ?V, which means that an amount of gas P0?V has been produced and collected in the storage circuit, a quantity P0VS?P0?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™, 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.

Frattolillo, A.

2006-06-01

239

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

SciTech Connect

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.

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

2013-11-01

240

Production of hydrogen and carbon by solar thermal methane splitting. I. The unseeded reactor  

Microsoft Academic Search

Solar thermal methane splitting was performed in a series of tests with an unseeded low capacity reactor. Effective screening of the reactor window from contact with carbon particles was achieved by application of the tornado flow configuration (J Solar Energy Eng 124 (2002) 206). The tests were performed at atmospheric pressure and at temperatures up to 1320K. An extent of

Meir Kogan; Abraham Kogan

2003-01-01

241

Productivity optimization of an industrial semi-batch polymerization reactor under safety constraints  

Microsoft Academic Search

In this work the operation of an industrial semi-batch reactor is optimized. In the reactor a strongly exothermic polymerization reaction takes place and the objective is to minimize the duration of the batch time. Various operational as well as quality and safety related constraints have to be met during the batch and at its final time. In particular, a cooling

O. Abel; A. Helbig; W. Marquardt; H. Zwick; T. Daszkowski

2000-01-01

242

Modelling and simulation of MOVPE of GaAs-based compound semiconductors in production scale Planetary Reactors  

NASA Astrophysics Data System (ADS)

The paper deals with the global, reactor scale modelling and simulation of metal organic vapour phase epitaxy (MOVPE) growth of GaAs-based III V compound semiconductor thin films in large production scale Planetary Reactor® with various wafer load configurations. Reactor hardware and growth process improvements that aim at increased reactant utilisation efficiency, reduced gas consumption and improved layer thickness and compositional uniformity control at low wafer edge exclusion are discussed. The modelling approach consists of the computation of macroscopic gas phase transport phenomena in the process zone e.g. flow, heat and mass transfer, including thin film deposition on hot surfaces. Modelling and simulation results are used to guide the reactor chamber design, gas inlet layout and the choice of process parameters leading to overall productivity enhancement and increased robustness of the process. The model accuracy for MOVPE growth of the AlGaAs and GaInP material system in large reaction chambers is demonstrated, and the advantages of using modelling to optimise hardware and process design are highlighted.

Brien, D.; Dauelsberg, M.; Christiansen, K.; Hofeldt, J.; Deufel, M.; Heuken, M.

2007-05-01

243

Nuclear Reactors. Revised.  

ERIC Educational Resources Information Center

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…

Hogerton, John F.

244

Production of human lysozyme in biofilm reactor and optimization of growth parameters of Kluyveromyces lactis K7.  

PubMed

Lysozyme (1,4-?-N-acetylmuramidase) is a lytic enzyme, which degrades the bacterial cell wall. Lysozyme has been of interest in medicine, cosmetics, and food industries because of its anti-bactericidal effect. Kluyveromyces lactis K7 is a genetically modified organism that expresses human lysozyme. There is a need to improve the human lysozyme production by K. lactis K7 to make the human lysozyme more affordable. Biofilm reactor provides high biomass by including a solid support, which microorganisms grow around and within. Therefore, the aim of this study was to produce the human lysozyme in biofilm reactor and optimize the growth conditions of K. lactis K7 for the human lysozyme production in biofilm reactor with plastic composite support (PCS). The PCS, which includes polypropylene, soybean hull, soybean flour, bovine albumin, and salts, was selected based on biofilm formation on PCS (CFU/g), human lysozyme production (U/ml), and absorption of lysozyme inside the support. To find the optimum combination of growth parameters, a three-factor Box-Behnken design of response surface method was used. The results suggested that the optimum conditions for biomass and lysozyme productions were different (27 °C, pH 6, 1.33 vvm for biomass production; 25 °C, pH 4, no aeration for lysozyme production). Then, different pH and aeration shift strategies were tested to increase the biomass at the first step and then secrete the lysozyme after the shift. As a result, the lysozyme production amount (141 U/ml) at 25 °C without pH and aeration control was significantly higher than the lysozyme amount at evaluated pH and aeration shift conditions (p?

Ercan, Duygu; Demirci, Ali

2013-07-01

245

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

SciTech Connect

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.

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

2012-01-01

246

Design and demonstration of an immobilized-cell fluidized-bed reactor for the efficient production of ethanol  

SciTech Connect

Initial studies have been carried out on the scale-up of a medium-scale (2-5 m tall with a 10.2-cm id), fluidized-bed reactor (FBR) designed for fuel ethanol fermentation using immobilized Zymomonas mobilis. These results suggest that further improvements in ethanol productivity along with good operability may be possible when compared with previous results at the bench scale (40-110 g ethanol/L/h) and present industrial reactors (2-10 g ethanol/L/h). On-line and off-line measurement and control systems are also described. Z. mobilis was immobilized in carrageenan at cell loading of approx 60 g (dry wt)/L of biocatalyst. The system is designed for determining optimal operating conditions for achieving high conversion and productivity with variations in feedstocks, temperature, flow rate, and column sizes.

Webb, O.F.; Davison, B.H.; Scott, T.C. [Oak Ridge National Lab., TN (United States)] [and others

1995-12-31

247

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

SciTech Connect

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.

Penetrante, B.M.; Hsiao, M.C.; Bardsley, J.N.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States); Kuthi, A. [Plasma and Materials Technologies, Inc., Chatsworth, CA (United States); Burkhart, C.P.; Bayless, J.R. [First Point Scientific, Inc., Agoura Hills, CA (United States)

1996-11-01

248

Continuous production of acrylamide using immobilized Brevibacterium sp. CH2 in a two-stage packed bed reactor  

Microsoft Academic Search

Summary Acrylamide was enzymatically produced from acrylonitrile (AN) in a two-stage packed bed reactor with immobilizedBrevibacterium sp. CH2 cells. Continuous production became possible because of higher tolerance of CH2 nitrile hydratase with respect to 6% AN than either the CH1 enzyme or theCorynebacterium enzyme of Nitto Chemical Industry which rapidly deactivated in a solution of 3% AN. The maximum volumetric

Cheo Young Lee; Ho Nam Chang

1990-01-01

249

Citric acid production by solid-state fermentation in a packed-bed reactor using Aspergillus niger  

Microsoft Academic Search

Kumara, a starch-containing root crop grown extensively in New Zealand, has been used as a substrate for citric acid production using Aspergillus niger in solid-state fermentation. When the process was operated in a packed-bed reactor, the bed loading was the most important operational parameter. The airflow rate and substrate particle size were also important but their net effects varied depending

Minyuan Lu; John D. Brooks; Ian S. Maddox

1997-01-01

250

Effects of plastic composite support and pH profiles on pullulan production in a biofilm reactor  

Microsoft Academic Search

Pullulan is a linear homopolysaccharide which is composed of glucose units and often described as ?-1, 6-linked maltotriose.\\u000a The applications of pullulan range from usage as blood plasma substitutes to environmental pollution control agents. In this\\u000a study, a biofilm reactor with plastic composite support (PCS) was evaluated for pullulan production using Aureobasidium pullulans. In test tube fermentations, PCS with soybean

Kuan-Chen Cheng; Ali Demirci; Jeffrey M. Catchmark

2010-01-01

251

Effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans in an airlift reactor  

Microsoft Academic Search

The effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans P56 in an airlift reactor was investigated. A maximum polysaccharide concentration (18.5 g\\/L), biomass dry weight (14.0 g\\/L),\\u000a polysaccharide yield (38.5%), and sugar utilization (96%) was achieved at a shear rate of 42 s?1. A. pullulans grown on beet molasses produced a mixture of pullulan

T. Roukas; G. Serris

1999-01-01

252

In-place condensation of reaction mixture using hollow fiber membrane reactors improved productivity of cell-free protein synthesis  

Microsoft Academic Search

The authors intended to raise the protein production rate of continuous flow cell-free (CFCF) translation by applying in-place condensation of the reaction mixture containing wheat germ extract (WGE), mRNA, tRNA, amino acids, and high energy biochemicals. A hollow fiber membrane reactor (HFMR) composed of a shell and 80 hollow fibers made of ultrafiltration (UF) membrane was developed for condensing the

Yuichi Yamamoto; Shunjiro Sugimoto; Xin-chun Shen; Teruyuki Nagamune; Shui-liang Yao; Eiji Suzuki

1999-01-01

253

Wine vinegar production using a noncommercial 100-litre bubble column reactor equipped with a novel type of dynamic sparger  

Microsoft Academic Search

This paper describes batch and semicontinu- ous acetic acid fermentations for wine vinegar produc- tion carried out with Acetobacter pasteurianus, and an industrial strain using a noncommercial 100-L bubble column reactor equipped with a novel type of gas-liquid dynamic sparger. Results showed acetification rates with this fermentor (i.e., an overall acetic acid productivity of 1.8 g\\/L\\/h and yield of 94%)

G. Fregapane; J. Nieto; M. D. Salvador

1999-01-01

254

Arrival time and magnitude of airborne fission products from the Fukushima, Japan, reactor incident as measured in Seattle, WA, USA  

Microsoft Academic Search

We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17-18 March 2011, we registered the first arrival of the airborne fission products 131-I, 132-I, 132-Te, 134-Cs, and 137-Cs in Seattle, WA, USA, by identifying their characteristic gamma

J. Diaz Leon; D. A. Jaffe; J. Kaspar; A. Knecht; M. L. Miller; R. G. H. Robertson; A. G. Schubert

2011-01-01

255

Arrival time and magnitude of airborne fission products from the Fukushima, Japan, reactor incident as measured in Seattle, WA, USA  

Microsoft Academic Search

We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17–18 March 2011, we registered the first arrival of the airborne fission products 131I, 132I, 132Te, 134Cs, and 137Cs in Seattle, WA, USA, by identifying their characteristic gamma

J. Diaz Leon; D. A. Jaffe; J. Kaspar; A. Knecht; M. L. Miller; R. G. H. Robertson; A. G. Schubert

2011-01-01

256

SynGas Production from Catalytic Steam Gasification of Municipal Solid Wastes in a Combined Fixed Bed Reactor  

Microsoft Academic Search

The catalytic steam gasification of municipal solid wastes (MSW) for syn-gas production was experimentally investigated in a combined fixed bed reactor using the newly developed tri-metallic catalyst. A series of experiments have been performed to explore the effects of catalyst presence, catalytic temperature, catalyst to MSW weight ratio (C\\/M) and steam to MSW ratio (S\\/M) on the composition and yield

Jianfen Li; Jianjun Liu; Shiyan Liao; Xiaorong Zhou; Rong Yan

2010-01-01

257

Using Monte Carlo transport to accurately predict isotope production and activation analysis rates at the University of Missouri research reactor  

Microsoft Academic Search

A detailed Monte Carlo N-Particle Transport Code (MCNP5) model of the University of Missouri research reactor (MURR) has been developed. The ability\\u000a of the model to accurately predict isotope production rates was verified by comparing measured and calculated neutron-capture\\u000a reaction rates for numerous isotopes. In addition to thermal (1\\/v) monitors, the benchmarking included a number of isotopes\\u000a whose (n, ?)

N. J. Peters; J. D. Brockman; J. D. Robertson

2009-01-01

258

Fission product retention in newly discovered organic-rich natural fission reactors at Oklo and Bangombe, Gabon  

SciTech Connect

The discovery of naturally occurring fission reactors in the rock strata of the Paleoproterozoic Francevillian Basin in the Republic of Gabon in equatorial West Africa led to several programs to define migration and/or retention of uranium and fissiogenic isotopes from/in the natural reactor zones. Although much understanding has been gained, new insight is needed regarding the chemical and physical parameters that control movement and retention of fission products over almost two billion years from/in the natural reactors. Seventeen known natural fission reactors sustained criticality for 0.1 to 1 million years in hydrothermally altered sedimentary rocks 1968 +/- 50 million years ago. These natural nuclear reactors attained criticality because of high concentrations of uranium in small pockets in uranium ores, the lack of neutron poisons, and because at the time they reached criticality, the abundance of [sup 235]U was five times greater than it is today. Water acted as a moderator, and temperature in the natural reactors was between 160 and 360[degrees]C. Both the uranium-rich pockets and the uranium ore bodies in which these pockets are located were formed when aqueous solutions moving through highly fractured zones in the Francevillian sedimentary rocks met organic-rich sediments. This resulted in the reduction of U(VI) in the dissolved uranyl ions to U(IV), causing the precipitation of pitchblende and uraninite. It has been proposed that between 2.2 and 1.9 billion years ago, the earth's atmosphere experienced a remarkable temporary rise in O[sub 2] content; this event may account for the uranium-bearing, oxidizing aqueous solutions in the Francevillian rocks.

Nagy, B.; Rigali, M.J. (Univ. of Arizona, Tucson (United States))

1993-01-01

259

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

SciTech Connect

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.

Cluett, C.; Clark, D.C. (Battelle Human Affairs Research Center, Seattle, WA (USA)); Pittenger, D.B. (Demographics Lab., Olympia, WA (USA))

1990-08-01

260

Model for continuous production of solvents from whey permeate in a packed bed reactor using cells of Clostridium acetobutylicum immobilized by adsorption onto bonechar  

Microsoft Academic Search

A mathematical model has been developed to describe the operation of a packed bed reactor for the continuous production of solvents from whey permeate. The model has been used to quantitate the amounts of different physiological\\/ morphological types of biomass present in the reactor. The majority of biomass is inert, i.e. it neither grows nor produces solvent. Only relatively small

N. Qureshi; A. H. J. Paterson; I. S. Maddox

1988-01-01

261

Low energy continuous reactor separator for the production of ethanol from corn grits/starch and biomass streams. 3rd Quarterly report, October 15, 1994--January 15, 1995.  

National Technical Information Service (NTIS)

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 of this reactor technology, and is directing the project. A Continuous...

1995-01-01

262

IN-SITU MONITORING OF PRODUCT STREAMS FROM A SPINNING TUBE-IN-TUBE REACTOR USING A METTLER-TOLEDO REACT-IR  

EPA Science Inventory

A Mettler-Toledo ReactIR system has been used for in-line, real-time monitoring of the product stream from a spinning tube-in-tube reactor (STT®, Kreido Laboratories, Camarillo California). This combination of a process intensified continuous-flow reactor and an in-situ analytic...

263

Investigation of the effects of radiolytic-gas bubbles on the long-term operation of solution reactors for medical-isotope production  

NASA Astrophysics Data System (ADS)

One of the most common and important medical radioisotopes is 99Mo, which is currently produced using the target irradiation technology in heterogeneous nuclear reactors. The medical isotope 99Mo can also be produced from uranium fission using aqueous homogeneous solution reactors. In solution reactors, 99Mo is generated directly in the fuel solution, resulting in potential advantages when compared with the target irradiation process in heterogeneous reactors, such as lower reactor power, less waste heat, and reduction by a factor of about 100 in the generation of spent fuel. The commercial production of medical isotopes in solution reactors requires steady-state operation at about 200 kW. At this power regime, the formation of radiolytic-gas bubbles creates a void volume in the fuel solution that introduces a negative coefficient of reactivity, resulting in power reduction and instabilities that may impede reactor operation for medical-isotope production. A model has been developed considering that reactivity effects are due to the increase in the fuel-solution temperature and the formation of radiolytic-gas bubbles. The model has been validated against experimental results from the Los Alamos National Laboratory uranyl fluoride Solution High-Energy Burst Assembly (SHEBA), and the SILENE uranyl nitrate solution reactor, commissioned at the Commissariat a l'Energie Atomique, in Valduc, France. The model shows the feasibility of solution reactors for the commercial production of medical isotopes and reveals some of the important parameters to consider in their design, including the fuel-solution type, 235U enrichment, uranium concentration, reactor vessel geometry, and neutron reflectors surrounding the reactor vessel. The work presented herein indicates that steady-state operation at 200 kW can be achieved with a solution reactor consisting of 120 L of uranyl nitrate solution enriched up to 20% with 235U and a uranium concentration of 145 kg/m3 in a graphite-reflected cylindrical geometry.

Souto Mantecon, Francisco Javier

264

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

NASA Astrophysics Data System (ADS)

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.

Alhassan, M.; Andresen, J. M.

2012-04-01

265

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

SciTech Connect

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.

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

1985-09-01

266

Production of structured lipids in a packed-bed reactor with thermomyces lanuginosa lipase  

Microsoft Academic Search

Lipase-catalyzed interesterification between fish oil and medium-chain TAG has been investigated in a packedbed reactor with\\u000a a commercially immobilized enzyme. The enzyme, a Thermomyces lanuginosa lipase immobilized on silica by granulation (lipozyme TL IM; Novozymes A\\/S, Bagsvaerd, Denmark), has recently been developed\\u000a for fat modification. This study focuses on the new characteristics of the lipase in a packed-bed reactor when

Xuebing Xu; Trine Porsgaard; Hong Zhang; Jens Adler-Nissen; Carl-Erik Høy

2002-01-01

267

Studies of Plutonium238 Production at the High Flux Isotope Reactor  

Microsoft Academic Search

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 (93 wt% ²³U\\/U) in the form of

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

2011-01-01

268

The production of zinc by thermal dissociation of zinc oxide—solar chemical reactor design  

Microsoft Academic Search

We describe the design, fabrication, and preliminary test of a novel solar chemical reactor for conducting the thermal dissociation of ZnO into zinc and oxygen at above 2000 K. The reactor configuration features a windowed rotating cavity-receiver lined with ZnO particles that are held by centrifugal force. With this arrangement, ZnO is directly exposed to high-flux solar irradiation and serves

P. Haueter; S. Moeller; R. Palumbo; A. Steinfeld

1999-01-01

269

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

SciTech Connect

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.

Kalu, E. Eric (FAMU-FSU College of Engineering, Tallahassee, FL); Chen, Ken Shuang

2008-01-01

270

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

PubMed

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

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

2012-02-01

271

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

PubMed Central

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

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

2011-01-01

272

Heterotrophic denitrification plays an important role in N?O production from nitritation reactors treating anaerobic sludge digestion liquor.  

PubMed

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

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

2014-10-01

273

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

274

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

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.

NONE

1995-05-01

275

Assessment of low-flow water quality in Richland Creek, Illinois  

USGS Publications Warehouse

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)

Freeman, W. O.; Schmidt, A. R.

1986-01-01

276

Environmental Monitoring Plan United States Department of Energy Richland Operations Office. Revision 2  

SciTech Connect

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.

NONE

1997-11-10

277

Evaluation of Machine Guarding course taught in Richland, Washington, September 1--3, 1992  

SciTech Connect

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.

Wright, T.S.

1993-03-01

278

Evaluation of Machine Guarding course taught in Richland, Washington, September 1--3, 1992  

SciTech Connect

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.

Wright, T.S.

1993-03-01

279

Citric acid production in a bubble-column reactor using cells of the yeast Candida guilliermondii immobilized by adsorption onto sawdust  

Microsoft Academic Search

Cells of the yeast Candida guilliermondii have been immobilized by adsorption onto sawdust and used in a bubble-column reactor for the continuous production of citric acid. At a dilution rate of 0.21 h?1 in a nitrinogen-limited medium containing glucose, a reactor productivity of 0.24 g l?1 h?1 has been achieved which is twice that observed in a batch fermenter culture

Djadjat Tisnadjaja; Noemi A. Gutierrez; Ian S. Maddox

1996-01-01

280

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

SciTech Connect

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.

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

2002-01-01

281

Preliminary risks associated with postulated tritium release from production reactor operation  

SciTech Connect

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.

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

1988-01-01

282

Application of a packed bed reactor for the production of hydrogen from cheese whey permeate: effect of organic loading rate.  

PubMed

The production of H2 was studied using a packed bed reactor with polyurethane foam acting as support material. Experiments were performed using mixed microflora under non sterile conditions. The system was initially operated with synthetic wastewater as the sole substrate. Subsequently, cheese whey permeate was added to the system at varying organic loading rates (OLR). The performance of the reactor was evaluated by applying a continuous decrease in OLR. As a result, a significant decrease in H2 yields (HY) was observed with the decrease in OLR from 18.8 to 6.3 g chemical oxygen demand (COD)/L d. Microbial analysis demonstrated that the prevalence of non-hydrogen producers, Sporolactobacillus sp. and Prevotella, was the main reason for low HYs obtained. This behavior indicates that the fermentation under non-sterile conditions was favored by high concentrations of substrate by creating an adverse environment for nonhydrogen producer organisms. PMID:24171421

Fernández, Camino; Carracedo, Begoña; Martínez, Elia Judith; Gómez, Xiomar; Morán, Antonio

2014-01-01

283

Continuous hydrogen production from co-digestion of municipal food waste and kitchen wastewater in mesophilic anaerobic baffled reactor.  

PubMed

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

Tawfik, A; El-Qelish, M

2012-06-01

284

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

SciTech Connect

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.

Sun, M.Y.; Davison, B.H.; Bienkowski, P.R. [Oak Ridge National Lab., TN (United States). Bioprocessing Research and Development Center]|[Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemical Engineering; Nghiem, N.P.; Webb, O. [Oak Ridge National Lab., TN (United States). Bioprocessing Research and Development Center

1997-08-01

285

Enhanced Production of Artemisinin by Hairy Root Cultivation of Artemisia annua in a Modified Stirred Tank Reactor.  

PubMed

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

Patra, Nivedita; Srivastava, Ashok K

2014-11-01

286

A novel membrane-integrated fermentation reactor system: application to pyruvic acid production in continuous culture by Torulopsis glabrata.  

PubMed

This paper describes the performance of a novel bio-reactor system, the membrane-integrated fermentation reactor (MFR), for efficient continuous fermentation. The MFR, equipped with an autoclavable polyvinylidene difluoride membrane, has normally been used for biological wastewater treatment. The productivity of the MFR system, applied to the continuous production of pyruvic acid by the yeast Torulopsis glabrata, was remarkably high. The volumetric productivity of pyruvic acid increased up to 4.2 g/l/h, about four times higher than that of batch fermentation. Moreover, the membrane was able to filter fermentation broth for more than 300 h without fouling even though the cell density of the fermentation broth reached 600 as OD(660). Transmembrane pressure, used as an indicator of membrane fouling, remained below 5 kPa throughout the continuous fermentation. These results clearly indicate that the MFR system is a simple and highly efficient system that is applicable to the fermentative production of a range of biochemicals. PMID:21318623

Sawai, Hideki; Mimitsuka, Takashi; Minegishi, Shin-Ichi; Henmi, Masahiro; Yamada, Katsushige; Shimizu, Sakayu; Yonehara, Tetsu

2011-08-01

287

Impact of the neutron flux on transmutation products at fusion reactor first-walls  

NASA Astrophysics Data System (ADS)

To develop and to assess the suitability of a material for use as the first structural wall in a fusion reactor, it is necessary to know the transmutation behaviour of the material. In the present paper we propose a transmutation calculational strategy and how this methodology is implemented in a computer code package, called CIBELES. The code system has been developed to calculate and especially to analyze the transmutations resulting from neutron irradiation. The system includes powerful computing methods for analysing the results, and uses the numerical calculation techniques of the ORIGEN code. The transmutation characteristics of two structural materials, AISI 316L austenitic steel and DIN 1.4914 martensitic steel have been evaluated for the peripheral target position in the High Flux Isotope Reactor (HFIR), and the first wall position of the Culham Conceptual Tokamak Reactor MarkIIA (CCTRII).

Sanz, J.; De La Fuente, R.; Perlado, J. M.

1988-07-01

288

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

DOEpatents

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.

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

2012-10-02

289

VBÉR-300 reactor system and power-generating units for regional nuclear power production  

Microsoft Academic Search

The basic design solutions and characteristics of the VBR-300 reactor system for the power-generating units of 150–300 MW(e)\\u000a nuclear power plants and regional nuclear heat-and-electricity plants are described. The reactor system implemented as a unit\\u000a is based on the technologies and solutions used for marine nuclear power systems, which have been corroborated by experience\\u000a in operating nuclear-powered icebreakers. The technical-economic

V. I. Kostin; V. V. Petrunin; O. B. Samoilov; A. V. Kurachenkov

2007-01-01

290

Novel Magnetically Fluidized Bed Reactor Development for the Looping Process: Coal to Hydrogen Production R&D  

SciTech Connect

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.

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

291

Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors  

Microsoft Academic Search

Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking

M. R. Jr. Louthan; S. L. West; D. Z. Nelson

1991-01-01

292

Hydrogen production for fuel cell application in an autothermal micro-channel reactor  

Microsoft Academic Search

Results concerning the coupling of the steam reforming (SR) and total oxidation (TOX) of methanol in a two-passage reactor are presented. A commercially available copper based catalyst is used for the steam reforming. For the total oxidation, a highly active cobalt oxide catalyst was developed. Both catalysts are used in form of thin layers immobilized on the wall of the

Pierre Reuse; Albert Renken; Katja Haas-Santo; Oliver Görke; Klaus Schubert

2004-01-01

293

Influence of biomass production and detachment forces on biofilm structures in a biofilm airlift suspension reactor  

Microsoft Academic Search

The influence of process conditions (substrate loading rate and detachment force) on the structure of biofilms grown on basalt particles in a Biofilm Airlift Sus- pension (BAS) reactor was studied. The structure of the biofilms (density, surface shape, and thickness) and mi- crobial characteristics (biomass yield) were investigated at substrate loading rates of 5, 10, 15, and 20 kg COD\\/

W. K. Kwok; C. Picioreanu; S. L. Ong; M. C. M. van Loosdrecht; W. J. Ng; J. J. Heijnen

1998-01-01

294

Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor.  

PubMed

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

Vaxelaire, S; Gonze, E; Merlin, G; Gonthier, Y

2008-12-01

295

Arrival time and magnitude of airborne fission products from the Fukushima, Japan, reactor incident as measured in Seattle, WA, USA  

E-print Network

We report results of air monitoring started due to the recent natural catastrophe on March 11, 2011 in Japan and the severe ensuing damage to the Fukushima nuclear reactor complex. On March 17-18, 2011 we detected the first arrival of the airborne fission products 131-I, 132-I, 132-Te, 134-Cs, and 137-Cs in Seattle, WA, USA, by identifying their characteristic gamma rays using a germanium detector. The highest detected activity to date is <~32 mBq/m^3 of 131-I.

Leon, J Diaz; Knecht, A; Miller, M L; Robertson, R G H; Schubert, A G

2011-01-01

296

Evaluation of selected ex-reactor accidents related to the tritium and medical isotope production mission at the FFTF  

SciTech Connect

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.

Himes, D.A.

1997-11-17

297

Tritium production analysis and management strategies for a Fluoride-salt-cooled high-temperature test reactor (FHTR)  

E-print Network

The Fluoride-salt-cooled High-temperature Test Reactor (FHTR) is a test reactor concept that aims to demonstrate the neutronics, thermal-hydraulics, materials, tritium management, and to address other reactor operational ...

Rodriguez, Judy N

2013-01-01

298

Production of Hydrogen and Syngas via Steam Gasification of Glycerol in a Fixed-Bed Reactor  

Microsoft Academic Search

Glycerol is one of the by-products of transesterification of fatty acids to produce bio-diesel. Increased production of bio-diesel\\u000a would lead to increased production of glycerol in Canadian market. Therefore, the production of hydrogen, syn gas and medium\\u000a heating value gas is highly desirable to improve the economics of bio-diesel production process. In this study, steam gasification\\u000a of pure and crude

T. Valliyappan; D. Ferdous; N. N. Bakhshi; A. K. Dalai

2008-01-01

299

Entropy production in a chemical system involving an autocatalytic reaction in an isothermal, continuous stirred tank reactor  

NASA Astrophysics Data System (ADS)

The rate of entropy production due to chemical reaction is calculated for various combinations of parameter values in the cubic autocatalator model in an isothermal, continuous stirred tank reactor (CSTR) proposed by Gray and Scott and by Escher and Ross. Values of the entropy production averaged over periods of limit cycle oscillations are compared with those in coexistent unstable stationary states. It is found that in ranges of the residence time over which there are limit cycles, the entropy production in coexisting stationary states increases as the residence time is shortened, i.e., as the system is removed farther from thermodynamic equilibrium. The average entropy production over a limit cycle is less than that in the corresponding stationary state over wide ranges of parameter values, but not necessarily for the whole oscillatory region. More specifically, the former inequality always prevails in ranges where the entropy production of stationary states is larger, i.e., the residence time is shorter, but in some cases the inequality is reversed in ranges of lower magnitudes of the entropy production.

Yoshida, Nobuo

1990-02-01

300

Update to the NARAC NNPP Non-Reactor Source Term Products  

SciTech Connect

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.

Vogt, P

2009-06-29

301

Conceptual Analysis of the Power Production of Fission Electric Cell Reactors  

SciTech Connect

The United States Department of Energy, Nuclear Energy Research Initiative (NERI) Direct Energy Conversion project has as its goal the development of direct energy conversion (DEC) processes suitable for commercial development. DEC is defined as any fission process that returns usable energy with no intermediate thermal process. This project includes the study of the fission electric cell (FEC). In the FEC, fission fragments exit the fuel element cathode and are collected by the cell anode. Previous work [1] has shown the potential of FECs, with theoretical efficiencies up to 60%. Inspection of this work indicates the need for additional system modeling prior to any conclusions regarding the final FEC reactor configuration. This paper builds on the previous work and outlines the development of models to facilitate design decisions. The models address criticality, design life, reactor configuration, and current-voltage characteristics. In addition, this paper proposes future work to complete the design model. (authors)

King, Donald; Rochau, Gary; Morrow, Charles; Cash, Jamie; Seidel, David; Slutz, Stephen [Sandia National Laboratories (United States)

2002-07-01

302

Process development of continuous hydrogen production by Enterobacter aerogenes in a packed column reactor  

Microsoft Academic Search

Hydrogen bioproduction from agro-industrial residues by Enterobacter aerogenes in a continuous packed column has been investigated and a complete reactor characterization is presented. Experimental runs carried out at different residence time, liable of interest for industrial application, showed hydrogen yields ranging from 1.36 to 3.02 mmolH2mmolуglucose or, in other words, from 37.5% to 75% of the theoretical hydrogen yield. A

E. Palazzi; B. Fabiano; P. Perego

2000-01-01

303

Continuous production of biogas from dairy manure using an innovative no-mix reactor  

Microsoft Academic Search

A 25 L no-mix anaerobic digester was designed and fabricated. The digester was designed to act as liquid-solid separator.\\u000a The sludges obtained from the bottom of the digester had high nitrogen and ash concentrations while the effluent had no offensive\\u000a odor. The performance of the no-mix digester was compared to that of a continuous stirred tank reactor at two temperatures

A. E. Ghaly; R. M. Ben-Hassan

1989-01-01

304

The influence of operational and water chemistry parameters on the deposits of corrosion products on fuel assemblies at nuclear power plants with VVER reactors  

NASA Astrophysics Data System (ADS)

The phenomenon involving a growth of pressure drop in the reactor core and redistribution of deposits in the reactor core and primary coolant circuit of a nuclear power station equipped with VVER-440 reactors is considered. A model is developed, the physicochemical foundation of which is based on the dependence of corrosion product transfer on the temperature and pH t value of coolant and on the correlation between the formation rate of corrosion products (Fe) (after subjecting the steam generators to decontamination) and rate with which they are removed from the circuit. The purpose of the simulation carried on the model is to predict the growth of pressure drop on the basis of field data obtained from nuclear power installations and correct the water chemistry (by adjusting the concentrations of KOH, H2, and NH3) so as to keep the pressure drop in the reactor at a stable level.

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

2011-07-01

305

CARBON COATED (CARBONOUS) CATALYST IN EBULLATED BED REACTOR FOR PRODUCTION OF OXYGENATED CHEMICALS FROM SYNGAS/CO2  

SciTech Connect

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.

Peizheng Zhou

2001-10-26

306

Modeling scaleup effects on a small pilot-scale fluidized-bed reactor for fuel ethanol production  

SciTech Connect

Domestic ethanol use and production are presently undergoing significant increases along with planning and construction of new production facilities. Significant efforts are ongoing to reduce ethanol production costs by investigating new inexpensive feedstocks (woody biomass) and by reducing capital and energy costs through process improvements. A key element in the development of advanced bioreactor systems capable of very high conversion rates is the retention of high biocatalyst concentrations within the bioreactor and a reaction environment that ensures intimate contact between substrate and biocatalyst. One very effective method is to use an immobilized biocatalyst that can be placed into a reaction environment that provides effective mass transport, such as a fluidized bed. Mathematical descriptions are needed based on fundamental principles and accepted correlations that describe important physical phenomena. We describe refinements and semi-quantitatively extend the predictive model of Petersen and Davison to a multiphase fluidized-bed reactor (FBR) that was scaled-up for ethanol production. Axial concentration profiles were evaluated by solving coupled differential equations for glucose and carbon dioxide. The pilot-scale FBR (2 to 5 m tall, 10.2-cm ID, and 23,000 L month{sup -1} capacity) was scaled up from bench-scale reactors (91 to 224 cm long, 2.54 to 3.81 cm ID, and 400 to 2,300 L month{sup -1} capacity). Significant improvements in volumetric productivites (50 to 200 g EtOH h{sup -1} L{sup -1} compared with 40 to 110 for bench-scale experiments and 2 to 10 for reported industrial benchmarks) and good operability were demonstrated.

Webb, O.F.; Davison, B.H.; Scott, T.C.

1995-09-01

307

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

Microsoft Academic Search

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 COâ product which drives the equilibrium limited WGSR

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

2005-01-01

308

Application of a multi-layer packed-bed reactor to citric acid production in solid-state fermentation using Aspergillus niger  

Microsoft Academic Search

Solid-state fermentation, using the fungus Aspergillus niger, has been employed for the production of citric acid from kumara, a starch-containing root crop. A multi-layer packed-bed reactor was designed and operated in an attempt to understand mass and heat transfer during the fermentation. Although only a limited understanding was obtained, the multi-layer packed-bed reactor improved the mass transfer considerably compared with

M. Y. Lu; I. S. Maddox; J. D. Brooks

1998-01-01

309

Design of adiabatic fixed-bed reactors for the partial oxidation of methane to synthesis gas. Application to production of methanol and hydrogen-for-fuel-cells  

Microsoft Academic Search

Adiabatic fixed-bed reactors for the catalytic partial oxidation (CPO) of methane to synthesis gas were designed at conditions suitable for the production of methanol and hydrogen-for-fuel-cells. A steady-state, one-dimensional heterogeneous reactor model was applied in the simulations. Intra-particle concentration gradients were taken into account explicitly, by solving the continuity equations in the catalyst pellet at each position along the fixed-bed

C. R. H. de Smet; R. J. Berger; GBMM Marin; J. C. Schouten

2001-01-01

310

Life cycle assessment of hydrogen production from S-I thermochemical process coupled to a high temperature gas reactor  

SciTech Connect

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)

Giraldi, M. R.; Francois, J. L.; Castro-Uriegas, D. [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac No. 8532, Col. Progreso, C.P. 62550, Jiutepec, Morelos (Mexico)

2012-07-01

311

The Phase Behavior Effect on the Reaction Engineering of Transesterification Reactions and Reactor Design for Continuous Biodiesel Production  

NASA Astrophysics Data System (ADS)

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 PFR

Csernica, Stephen N.

312

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

313

Method for fabricating wrought components for high-temperature gas-cooled reactors and product  

DOEpatents

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.

Thompson, Larry D. (San Diego, CA); Johnson, Jr., William R. (San Diego, CA)

1985-01-01

314

Glutamate production from CO{sub 2} by marine cyanobacterium synechococcus sp. using a novel biosolar reactor employing light-diffusing optical fibers  

SciTech Connect

A photobioreactor was constructed in the form of a Perspex column 900 mm tall with an internal diameter of 70 mm. The reactor volume was 1.8 L and the light source consisted of a metal-halide lamp to reproduce sunlight. Light was distributed through the culture using a new type of optical fiber that diffuses light out through its surface, perpendicular to the fiber axis. A cluster of 661 light-diffusing optical fibers (LDOFs) pass from the light source through the reactor column (60-cm culture depth) and are connected to a mirror at the top of the reactor. This biosolar reactor has been used for the production of glutamate from CO{sub 2} by the marine cyanobacterium Synechococcus sp. NKBG040607. We present here details of the construction of the biosolar reactor and characterization of its properties. The effect of light intensity on glutamate production was measured. Carbon dioxide-to-glutarnate conversion ratios were determined at different cell densities: the maximum conversion ratio (28%) was achieved at a cell density of 3{times}10{sup 8} cells/mL. A comparison of glutamate production using the LDOF biosolar reactor described here with production by batch culture using free or immobilized cells showed that use of an optical-fiber biosolar reactor increased glutamate-production efficiency 6.75-fold. We conclude that as a result of its high surface-to-volume ratio (692/m) increased photoproduction of useful compounds may be achieved. Such a system is generally applicable to all aspects of photobiotechnology.

Matsunaga, Tadashi; Takeyama, Haruko; Sudo, Hiroaki [Tokyo Univ. of Agriculture and Technology (Japan)] [and others

1991-12-31

315

Experimental studies and comprehensive reactor modeling of hydrogen production by the catalytic reforming of crude ethanol in a packed bed tubular reactor over a Ni\\/Al 2 O 3 catalyst  

Microsoft Academic Search

A rigorous numerical model was developed to simulate the production of hydrogen from the reforming of crude ethanol in a packed bed tubular reactor (PBTR). The model was based on the coupling of mass and energy balance equations as well as a new kinetic model developed for the process. The simulation results for crude ethanol conversion were found to be

Ahmed Aboudheir; Abayomi Akande; Raphael Idem; Ajay Dalai

2006-01-01

316

A Fisheries Evaluation of the Richland and Toppenish/Satus Canal Fish Screening Facilities, Spring 1986 Annual Report.  

SciTech Connect

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.

Neitzel, D.A.; Abernethy, C. Scott; Lusty, E. William

1987-05-01

317

Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors  

SciTech Connect

Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking in weld heat-affected zones and that the overall weld quality was excellent. The evaluation also revealed weld fusion zone discontinuities such as incomplete penetration, incomplete fusion, inclusions, underfill at weld roots and hot cracks. Service induced extension of these discontinuities was generally not significant although stress corrosion cracking in one weld fusion zone was noted. One set of UT indications was caused by metallurgical discontinuities at the fusion boundary of an extra weld. This extra weld, not apparent on the outer pipe surface, was slightly overlapping and approximately parallel to the weld being inspected. This extra weld was made during a pipe repair, probably associated with initial construction processes. The two nearly parallel welds made accurate assessment of the UT signal difficult. The implications of these observations to the inspection and repair of process water systems of nuclear reactors is discussed.

Louthan, M.R. Jr.; West, S.L.; Nelson, D.Z.

1991-01-01

318

Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors  

SciTech Connect

Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking in weld heat-affected zones and that the overall weld quality was excellent. The evaluation also revealed weld fusion zone discontinuities such as incomplete penetration, incomplete fusion, inclusions, underfill at weld roots and hot cracks. Service induced extension of these discontinuities was generally not significant although stress corrosion cracking in one weld fusion zone was noted. One set of UT indications was caused by metallurgical discontinuities at the fusion boundary of an extra weld. This extra weld, not apparent on the outer pipe surface, was slightly overlapping and approximately parallel to the weld being inspected. This extra weld was made during a pipe repair, probably associated with initial construction processes. The two nearly parallel welds made accurate assessment of the UT signal difficult. The implications of these observations to the inspection and repair of process water systems of nuclear reactors is discussed.

Louthan, M.R. Jr.; West, S.L.; Nelson, D.Z.

1991-12-31

319

Use of Glucose Oxidase in a Membrane Reactor for Gluconic Acid Production  

NASA Astrophysics Data System (ADS)

This article aims at the evaluation of the catalytic performance of glucose oxidase (GO) (EC.1.1.3.4) for the glucose/gluconic acid conversion in the ultrafiltration cell type membrane reactor (MB-CSTR). The reactor was coupled with a Millipore ultrafiltration-membrane (cutoff of 100 kDa) and operated for 24 h under agitation of 100 rpm, pH 5.5, and 30°C. The experimental conditions varied were the glucose concentration (2.5, 5.0, 10.0, 20.0, and 40.0 mM), the feeding rate (0.5, 1.0, 3.0, and 6.0/h), dissolved oxygen (8.0 and 16.0 mg/L), GO concentration (2.5, 5.0, 10.0, and 20.0 UGO/mL), and the glucose oxidase/catalase activity ratio (UGO/UCAT)(1?0, 1?10, 1?20, and 1?30). A conversion yield of 80% and specific reaction rate of 40×10-4 mmol/h·UGO were attained when the process was carried out under the following conditions: D=3.0/h, dissolved oxygen=16.0 mg/L, [G]=40 mM, and (UGO/UCAT)=1?20. A simplified model for explaining the inhibition of GO activity by hydrogen peroxide, formed during the glucose/gluconic acid conversion, was presented.

Das Neves, Luiz Carlos Martins; Vitolo, Michele

320

Production and oxidative stability of a human milk fat substitute produced from lard by enzyme technology in a pilot packed-bed reactor  

Microsoft Academic Search

Residence time and time of production were investigated during the enzymatic production of a specific structured lipid\\/human milk fat substitute (SL-HMFS), on a kg scale, made from lard and soybean oil fatty acids, using a packed-bed reactor and short path distillation. There were no effects of residence time or time of production on C18:2 and C18:3 incorporation or on acyl

Nina Skall Nielsen; Tiankui Yang; Xuebing Xu; Charlotte Jacobsen

2006-01-01

321

Sensitivity Analysis of Fission Product Concentrations for Light Water Reactor Burned Fuel  

Microsoft Academic Search

The accurate prediction of fission product concentrations (FPCs) is necessary for application of the burnup credit to nuclear facilities. In order to specify important nuclear data for the accurate prediction of FPC, we extensively evaluate the sensitivities of FPC to nuclear data with the depletion perturbation theory. The target fission products are twelve important ones for the burnup credit, Mo-95,

Go CHIBA; Keisuke OKUMURA; Akito OIZUMI; Masaki SAITO

2010-01-01

322

Continuous production of lipase-catalyzed biodiesel in a packed-bed reactor: optimization and enzyme reuse study.  

PubMed

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

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

323

Continuous Production of Lipase-Catalyzed Biodiesel in a Packed-Bed Reactor: Optimization and Enzyme Reuse Study  

PubMed Central

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

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

324

Modeling of fusion activation-product release and reactor damage from rapid structural oxidation  

SciTech Connect

Rapid structural oxidation resulting from accidental high-temperature exposure of activated fusion material to reactive gases is potentially an important mechanism in the release of radioactivity or damage to the reactor. The reaction rates of 316 SS, HT-9, V-alloy, and TZM with air have been examined on the basis of theory and previous experiments. The low melting points of the primary oxides of the base metals cause oxidation of V-alloy and TZM to become very rapid above approximately 700/sup 0/C, although vanadium species are far less volatile. The Mo content of 316 SS and HT-9 appears to make them susceptible to rapid oxidation above approximately 1000 and 1300/sup 0/C, respectively. At such temperatures, the oxidation rates of steels are predicted to be over an order of magnitude less than Mo and V. The volatilization rates of TZM are expected to be several orders of magnitude higher than the other materials studied.

Piet, S.J.; Kazimi, M.S.; Lidsky, L.M.

1983-01-01

325

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

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.

Not Available

1994-11-01

326

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

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.

Shivayogimath, C.B.; Ramanujam, T.K.

1998-07-01

327

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

328

Biofuels from Pyrolysis: Catalytic Biocrude Production in a Novel, Short-Contact Time Reactor  

SciTech Connect

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.

None

2010-01-01

329

Part I. Fuel-motion diagnostics in support of fast-reactor safety experiments. Part II. Fission product detection system in support of fast reactor safety experiments  

Microsoft Academic Search

In all destructive fast-reactor safety experiments at TREAT, fuel motion and cladding failure have been monitored by the fast-neutron\\/gamma-ray hodoscope, providing experimental results that are directly applicable to design, modeling, and validation in fast-reactor safety. Hodoscope contributions to the safety program can be considered to fall into several groupings: pre-failure fuel motion, cladding failure, post-failure fuel motion, steel blockages, pretest

A. Devolpi; R. C. Doerner; C. L. Fink; J. P. Regis; E. A. Rhodes; G. S. Stanford; T. H. Braid; R. E. Boyar

1986-01-01

330

Transesterification of rapeseed oil for biodiesel production in trickle-bed reactors packed with heterogeneous Ca/Al composite oxide-based alkaline catalyst.  

PubMed

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

Meng, Yong-Lu; Tian, Song-Jiang; Li, Shu-Fen; Wang, Bo-Yang; Zhang, Min-Hua

2013-05-01

331

Process engineering and optimization of glycerol separation in a packed-bed reactor for enzymatic biodiesel production.  

PubMed

A process model for efficient glycerol separation during methanolysis in an enzymatic packed-bed reactor (PBR) was developed. A theoretical glycerol removal efficiency from the reaction mixture containing over 30% methyl esters was achieved at a high flow rate of 540 ml/h. To facilitate a stable operation of the PBR system, a batch reaction prior to continuous methanolysis was conducted using oils with different acid values and immobilized lipases pretreated with methyl esters. The reaction system successfully attained the methyl ester content of over 30% along with reduced viscosity and water content. Furthermore, to obtain a high methyl ester content above 96% continuously, long-term lipase stability was confirmed by operating a bench-scale PBR system for 550 h, in which the intermediates containing methyl esters and residual glycerides were fed into the enzyme-packed columns connected in series. Therefore, the developed process model is considered useful for industrial biodiesel production. PMID:21924607

Hama, Shinji; Tamalampudi, Sriappareddy; Yoshida, Ayumi; Tamadani, Naoki; Kuratani, Nobuyuki; Noda, Hideo; Fukuda, Hideki; Kondo, Akihiko

2011-11-01

332

Arrival time and magnitude of airborne fission products from the Fukushima, Japan, reactor incident as measured in Seattle, WA, USA  

E-print Network

We report results of air monitoring started due to the recent natural catastrophe on 11 March 2011 in Japan and the severe ensuing damage to the Fukushima Dai-ichi nuclear reactor complex. On 17-18 March 2011, we registered the first arrival of the airborne fission products 131-I, 132-I, 132-Te, 134-Cs, and 137-Cs in Seattle, WA, USA, by identifying their characteristic gamma rays using a germanium detector. We measured the evolution of the activities over a period of 23 days at the end of which the activities had mostly fallen below our detection limit. The highest detected activity amounted to 4.4 +/- 1.3 mBq/m^3 of 131-I on 19-20 March.

J. Diaz Leon; D. A. Jaffe; J. Kaspar; A. Knecht; M. L. Miller; R. G. H. Robertson; A. G. Schubert

2011-03-24

333

Design and demonstration of an immobilized-cell fluidized-bed reactor for the efficient production of ethanol  

SciTech Connect

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.

Webb, O.F.; Scott, T.C.; Davison, B.H.; Scott, C.D.

1994-06-01

334

Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface  

SciTech Connect

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.

Joseph W. Newkirk; Richard K. Brow

2010-01-21

335

Hydrogen production from banyan leaves using an atmospheric-pressure microwave plasma reactor.  

PubMed

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

Lin, Yuan-Chung; Wu, Tzi-Yi; Jhang, Syu-Ruei; Yang, Po-Ming; Hsiao, Yi-Hsing

2014-06-01

336

Continuous production of lactic acid from glucose and lactose in a cell-recycle reactor  

Microsoft Academic Search

Growth and lactic acid production ofLactobacillus delbreuckii were compared using glucose and lactose as carbon sources. A continuous-flow stirred-tank fermenter was coupled with a cross-flow\\u000a filtration unit to permit operation at high-cell concentrations. At steady state, yeast extract requirements for lactic-acid\\u000a production were lower when glucose was used as a substrate than with lactose fermentation. Once steady state was obtained,

Eric Ohleyer; Charles R. Wilke; Harvey W. Blanch

1985-01-01

337

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

Microsoft Academic Search

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

Xiao Wu

2009-01-01

338

Neutronic and thermal hydraulic analysis for production of fission molybdenum-99 at Pakistan Research Reactor1  

Microsoft Academic Search

Neutronic and thermal hydraulic analysis for the fission molybdenum-99 production at PARR-1 has been performed. Low enriched uranium foil (<20% 235U) will be used as target material. Annular target designed by ANL (USA) will be irradiated in PARR-1 for the production of 100 Ci of molybdenum-99 at the end of irradiation, which will be sufficient to prepare required 99Mo\\/99mTc generators

A. Mushtaq; Massod Iqbal; Ishtiaq Hussain Bokhari; Tariq Mahmood; Tayyab Mahmood; Zahoor Ahmad; Qamar Zaman

2008-01-01

339

The kinetics of inhibitor production resulting from hydrothermal deconstruction of wheat straw studied using a pressurised microwave reactor  

PubMed Central

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

2014-01-01

340

Impact of organic loading rate on biohydrogen production in an up-flow anaerobic packed bed reactor (UAnPBR).  

PubMed

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

Ferraz, Antônio Djalma Nunes; Zaiat, Marcelo; Gupta, Medhavi; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George

2014-07-01

341

Optimization of continuous hydrogen production from co-fermenting molasses with liquid swine manure in an anaerobic sequencing batch reactor.  

PubMed

This study investigated and optimized the operational conditions for continuous hydrogen production from sugar beet molasses, co-fermented with liquid swine manure in an anaerobic sequencing batch reactor. Results indicated that pH, HRT and total solids content in the swine manure (TS) had significant impact on all the responses such as biogas production rate (BPR), hydrogen content (HC), hydrogen production rate (HPR), and hydrogen yield (HY), although the highest level of each response was achieved at different combination of the three variables. The maximum BPR, HC, HPR and HY of 32.21 L/d, 30.51%, 2.23 L/d/L and 1.57 mol-H2/mol-sugar were estimated at the optimal pH, HRT, and TS of 5.55, 15.78 h, and 0.71% for BPR; 5.22, 12.04, and 0.69 for HC; 5.32, 15.62, and 0.78% for HPR; and 5.36, 17.56, and 0.74% for HY, respectively. Good linear relationships of the predicted and tested results for all the parameters were observed. PMID:23567702

Wu, Xiao; Lin, Hongjian; Zhu, Jun

2013-05-01

342

Continuous Recycle Enzymatic Membrane Reactor System for In-situ Production of Pure and Sterile Glucose Solution  

NASA Astrophysics Data System (ADS)

In this study, an efficient Continuous Recycle Enzymatic Membrane Reactor (CREMR) system for production of in-situ glucose solution was developed and the Simultaneous Gelatinization, Liquefaction and Saccharification (SGLS) carried out at temperatures below 60°C, is proposed to replace the conventional starch hydrolysis. Using a 30 kD polysulfone hollow fibre membrane and 10% (w/w) tapioca starch concentration, it is found that during the steady state continuous operation, the SGLS process in the CREMR at temperatures of 55 and 60°C and trans-membrane pressures of 0.5 and 1 bar has produced a steady state glucose concentration in the permeate stream as high as 64 g L-1 over a period of eight hours operation. The glucose solution obtained is of high purity greater than 99.9% and sterile, hence can be utilised as intravenous dripping solution and other medical products without post-treatments. In addition, the CREMR system is also relatively easy to scale-up, has a smaller footprint c.f. conventional systems, thus allowing in-situ production.

Sarbatly, Rosalam; Krishnaiah, Duduku; England, Richard

343

The Ongoing Impact of the U.S. Fast Reactor Integral Experiments Program  

SciTech Connect

The creation of a large database of integral fast reactor physics experiments advanced nuclear science and technology in ways that were unachievable by less capital intensive and operationally challenging approaches. They enabled the compilation of integral physics benchmark data, validated (or not) analytical methods, and provided assurance of future rector designs The integral experiments performed at Argonne National Laboratory (ANL) represent decades of research performed to support fast reactor design and our understanding of neutronics behavior and reactor physics measurements. Experiments began in 1955 with the Zero Power Reactor No. 3 (ZPR-3) and terminated with the Zero Power Physics Reactor (ZPPR, originally the Zero Power Plutonium Reactor) in 1990 at the former ANL-West site in Idaho, which is now part of the Idaho National Laboratory (INL). Two additional critical assemblies, ZPR-6 and ZPR-9, operated at the ANL-East site in Illinois. A total of 128 fast reactor assemblies were constructed with these facilities [1]. The infrastructure and measurement capabilities are too expensive to be replicated in the modern era, making the integral database invaluable as the world pushes ahead with development of liquid metal cooled reactors.

John D. Bess; Michael A. Pope; Harold F. McFarlane

2012-11-01

344

Tar Production from Biomass Pyrolysis in a Fluidized Bed Reactor: A Novel Turbulent Multiphase Flow Formulation  

NASA Technical Reports Server (NTRS)

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.

Bellan, J.; Lathouwers, D.

2000-01-01

345

Treatment of HMX-production wastewater in an aerobic granular reactor.  

PubMed

Aerobic granules were applied to the treatment of HMX-production wastewater using a gradual domestication method in a SBR. During the process, the granules showed a good settling ability, a high biomass retention rate, and high biological activity. After 40 days of stable operation, aerobic granular sludge performed very effectively in the removal of carbon and nitrogen compounds from HMX-production wastewater. Organic matter removal rates up to 97.57% and nitrogen removal efficiencies up to 80% were achieved during the process. Researchers conclude that using aerobic granules to treat explosive wastewater has good prospects for success. PMID:23697233

Zhang, Jin-Hua; Wang, Min-Hui; Zhu, Xiao-Meng

2013-04-01

346

Production of hydrogen and carbon by solar thermal methane splitting. II. Room temperature simulation tests of seeded solar reactor  

Microsoft Academic Search

In the design of a solar thermal methane splitting reactor seeded with powder particles, care must be taken to prevent destruction of the reactor window by contact with incandescent solid particles. The method of screening the window by application of the tornado flow configuration (Int. J. Hydrogen Energy 28 (11) (2003) 1187) inside the reactor enclosure was studied experimentally by

Abraham Kogan; Meir Kogan; Shmuel Barak

2004-01-01

347

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 ...

348

Enzymatic production of L-tryptophan in a reverse micelle reactor  

Microsoft Academic Search

The enzymatic production of tryptophan from indole and serine was investigated in a micellar solution of the surfactant Brij 56 in cyclohexane. An anion exchanger was employed to facilitate the transfer of tryptophan and serine between the water pool of the reverse micelle and the bulk organic phase. The influence of potassium ion, water content, pH, and co-surfactant on enzyme

D. K. Eggers; H. W. Blanch

1988-01-01

349

High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor  

SciTech Connect

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.

Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

2011-07-31

350

Potential role of the Fast Flux Test Facility and the advanced test reactor in the U.S. tritium production system  

Microsoft Academic Search

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

Dautel

1996-01-01

351

The development of a mechanistic model to investigate the impacts of the light dynamics on algal productivity in a Hydraulically Integrated Serial Turbidostat Algal Reactor (HISTAR)  

Microsoft Academic Search

A deterministic model was developed to predict microalgal productivity within the Hydraulically Integrated Serial Turbidostat Algal Reactor (HISTAR). HISTAR consists of two turbidostats, which concomitantly inoculate the first of a series of CFSTRs. The CFSTRs function as a biomass amplifier of the inoculated culture. The model included an analysis of the internal light dynamics within each CFSTR and the effect

Barbara C. Benson; Maria T. Gutierrez-Wing; Kelly A. Rusch

2007-01-01

352

Biogas production from wheat straw in batch and UASB reactors: the roles of pretreatment and seaweed hydrolysate as a co-substrate.  

PubMed

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

Nkemka, Valentine Nkongndem; Murto, Marika

2013-01-01

353

Continuous and scalable production of well-controlled noble-metal nanocrystals in milliliter-sized droplet reactors.  

PubMed

Noble-metal nanocrystals are essential to applications in a variety of areas, including catalysis, electronics, and photonics. Despite the large number of reports, there still exists a gap between academic studies and industrial applications due to the lack of ability to produce the nanocrystals in large quantities while still maintaining the good uniformity and precise controls. Because the nucleation and growth of colloidal nanocrystals are highly sensitive to experimental conditions, it is impractical to scale up their production by simply increasing the reaction volume. Here we report a new and practical approach based on milliliter-sized droplet reactors to the scalable production of nanocrystals. The droplets of 0.25 mL in volume were produced as a continuous flow in a fluidic device assembled from commercially available components. As a proof of concept, we have synthesized Pd, Au, and Pd-M (M = Au, Pt, and Ag) nanocrystals with controlled sizes, shapes, compositions, and structures on a scale of 1-10 g per hour (e.g., 3.6 g per hour for Pd cubes of 10 nm in edge length). PMID:25272334

Zhang, Lei; Niu, Guangda; Lu, Ning; Wang, Jinguo; Tong, Limin; Wang, Liduo; Kim, Moon J; Xia, Younan

2014-11-12

354

Efficient production of methane from artificial garbage waste by a cylindrical bioelectrochemical reactor containing carbon fiber textiles.  

PubMed

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

Sasaki, Daisuke; Sasaki, Kengo; Watanabe, Atsushi; Morita, Masahiko; Igarashi, Yasuo; Ohmura, Naoya

2013-01-01

355

Efficient production of methane from artificial garbage waste by a cylindrical bioelectrochemical reactor containing carbon fiber textiles  

PubMed Central

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

2013-01-01

356

Effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans in an airlift reactor.  

PubMed

The effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans P56 in an airlift reactor was investigated. A maximum polysaccharide concentration (18.5 g/L), biomass dry weight (14.0 g/L), polysaccharide yield (38.5%), and sugar utilization (96%) was achieved at a shear rate of 42 s(-1). A. pullulans grown on beet molasses produced a mixture of pullulan and other polysaccharides. The highest value of pullulan proportion (30% of total polysaccharide) was obtained at a low shear rate (42 s(-1)). The apparent viscosity of the fermentation broth increased as the shear rate increased up to 42 s(-1) and then decreased. On the other hand, the dissolved oxygen concentration and the volumetric mass transfer coefficient increased with the increase of the shear rate from 21 to 84 s(-1). The external addition of L-glutamic acid, olive oil, and Tween-80 improved significantly the production of crude polysaccharide (27.0 g/L), but the pullulan content of the polysaccharide was low (20%). PMID:15304678

Roukas, T; Serris, G

1999-04-01

357

Organic loading rate impact on biohydrogen production and microbial communities at anaerobic fluidized thermophilic bed reactors treating sugarcane stillage.  

PubMed

This study aimed to evaluate the effect of high organic loading rates (OLR) (60.0-480.00 kg COD m(-3)d(-1)) on biohydrogen production at 55°C, from sugarcane stillage for 15,000 and 20,000 mg CODL(-1), in two anaerobic fluidized bed reactors (AFBR1 and AFBR2). It was obtained, for H2 yield and content, a decreasing trend by increasing the OLR. The maximum H2 yield was observed in AFBR1 (2.23 mmol g COD added(-1)). The volumetric H2 production was proportionally related to the applied hydraulic retention time (HRT) of 6, 4, 2 and 1h and verified in AFBR1 the highest value (1.49 L H2 h(-1)L(-1)). Among the organic acids obtained, there was a predominance of lactic acid (7.5-22.5%) and butyric acid (9.4-23.8%). The microbial population was set with hydrogen-producing fermenters (Megasphaera sp.) and other organisms (Lactobacillus sp.). PMID:24632626

Santos, Samantha Christine; Rosa, Paula Rúbia Ferreira; Sakamoto, Isabel Kimiko; Varesche, Maria Bernadete Amâncio; Silva, Edson Luiz

2014-05-01

358

Measurement of airborne fission products in Chapel Hill, NC, USA from the Fukushima I reactor accident  

E-print Network

We present measurements of airborne fission products in Chapel Hill, NC, USA, from 62 days following the March 11, 2011, accident at the Fukushima I Nuclear Power Plant. Airborne particle samples were collected daily in air filters and radio-assayed with two high-purity germanium (HPGe) detectors. The fission products I-131 and Cs-137 were measured with maximum activities of 4.2 +/- 0.6 mBq/m^2 and 0.42 +/- 0.07 mBq/m^2 respectively. Additional activity from I-131, I-132, Cs-134, Cs-136, Cs-137 and Te-132 were measured in the same air filters using a low-background HPGe detector at the Kimballton Underground Research Facility (KURF).

MacMullin, S; Green, M P; Henning, R; Holmes, R; Vorren, K; Wilkerson, J F

2011-01-01

359

Reactor comparison and scale-up for the microaerobic production of 2,3-butanediol by Enterobacter aerogenes at constant oxygen transfer rate  

Microsoft Academic Search

Stirred tank (STR), bubble column (BCR) and airlift (ALR) bioreactors of 0.05 and 1.5 m3 total volume were compared for the production of 2,3-butanediol using Enterobacter aerogenes under microaerobic conditions. Batch fermentations were carried out at constant oxygen transfer rate (OTR=35 mmol\\/lh). At 0.05 m3 scale, the STR reactor achieved much higher biomass and product concentrations than the BCR and

T.-G. Byun; A.-P. Zeng; W.-D. Deckwer

1994-01-01

360

STUDIES OF SHORT-LIVED FISSION PRODUCTS AND THEIR IMPORTANCE TO REACTOR TECHNOLOGY  

Microsoft Academic Search

A systematic study of the decay schemes of some of the important alkali ; metal isotopes was made. Information is available on 17.8-minute Rb⁸⁸, ; 14.9-minute Rb⁸⁹, and 2.6-minute Rb⁹°. The decay characteristics of ; these nuclides show the general features exhibited by all of the short-lived ; fission products studied so far, namely, the short half-lives are related to

G. D. OKelley; E. Eichler; N. R. Johnson

1958-01-01

361

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

SciTech Connect

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.

Mahesh Iyer; Shwetha Ramkumar; Liang-Shih Fan

2006-03-31

362

A MODEL FOR PREDICTING FISSION PRODUCT ACTIVITIES IN REACTOR COOLANT: APPLICATION OF MODEL FOR ESTIMATING I-129 LEVELS IN RADIOACTIVE WASTE  

SciTech Connect

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.

Lewis, B.J.; Husain, A.

2003-02-27

363

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)

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.

Dominguez, Jesus; Sibille, Laurent

2010-01-01

364

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

365

Electrochemical enhancement of glucose oxidase kinetics : gluconic acid production with anion exchange membrane reactor.  

SciTech Connect

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.

Hestekin, J.A.; Lin, Y. P.; Frank, J.; Snyder, S.; St. Martin, E.; Energy Systems

2002-09-01

366

Development Program of IS Process Pilot Test Plant for Hydrogen Production With High-Temperature Gas-Cooled Reactor  

SciTech Connect

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)

Jin Iwatsuki; Atsuhiko Terada; Hiroyuki Noguchi; Yoshiyuki Imai; Masanori Ijichi; Akihiro Kanagawa; Hiroyuki Ota; Shinji Kubo; Kaoru Onuki; Ryutaro Hino [Japan Atomic Energy Agency (Japan)

2006-07-01

367

Continuous ethanol production in biofilm reactors containing plastic composite rings and discs  

SciTech Connect

Biofilms are natural forms of cell immobilization in which microorganisms attach to solid supports. At ISU we have developed plastic composite-supports (50% agricultural material, and 50% polypropylene) which stimulate biofilm formation and which can supply micronutrients to the attached microorganism. These plastic supports are produced by twin-screw high temperature extrusion producing ring or discs. For continuous ethanol fermentations with Saccharomyces cerevisiae (ATCC 24859), each packed-bed bioreactors (50 ml) contained plastic composite-rings and -discs, or polypropylene rings (control) with support surface areas of 160 cm{sup 2}, and operated at 30{degrees}C. For polypropylene rings, cell-washout occurred at dilution rates of 1.9 h{sup -1} in 0.6% yeast extract medium, and at 0.48{sup -1} in {ge}0.4% ammonium sulfate medium. With plastic composite-support bioreactors, however, S. cerevisiae at a dilution rate of 1.92 h{sup -1} produced 50 g/l/h with 100% expected theoretical conversions of glucose to ethanol. Also, repeated batch fermentations were performed for 11 different composite-supports in medium with varying concentrations of yeast extract to 0% nitrogen. S. cerevisiae with plastic composite-supports whereas with polypropylene supports, ethanol production was reduced significantly. The plastic composite-support blend selected for best performance contained 40% ground soybean hulls, 5% soybean flour, 5% yeast extract, mineral salts, and 50% polypropylene. Therefore, increased productivity in low cost medium can be achieved beyond conventional fermentations by using this novel bioreactor design.

Demirci, A.; Pometto, A.L. III; Kai-Lai, G. [Iowa State Univ., Ames, IA (United States)] [and others

1995-11-01

368

Production of medical radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for cancer treatment and arterial restenosis therapy after PTCA  

SciTech Connect

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.

Knapp, F.F. Jr.; Beets, A.L.; Mirzadeh, S.; Alexander, C.W.; Hobbs, R.L.

1998-06-01

369

Hydrogen production by steam-gasification of petroleum coke using concentrated solar power—II Reactor design, testing, and modeling  

Microsoft Academic Search

The solar chemical reactor technology for the steam-gasification of petcoke is presented. The reactor features a continuous vortex flow of steam laden with petcoke particles confined to a cavity receiver and directly exposed to concentrated solar radiation. A 5kW prototype reactor tested in a high-flux solar furnace in the range 1300–1800K yielded up to 87% petcoke conversion in a single

A. Z’Graggen; P. Haueter; D. Trommer; M. Romero; J. C. de Jesus; A. Steinfeld

2006-01-01

370

Analysis of coolability of the control rods of a Savannah River Site production reactor with loss of normal forced convection cooling  

SciTech Connect

An analytical study of the coolability of the control rods in the Savannah River Site (SRS) K-Production Reactor under conditions of loss of normal forced convection cooling has been performed. The study was performed as part of the overall safety analysis of the reactor supporting its restart. The analysis addresses the buoyancy-driven flow over the control rods that occurs when forced cooling is lost, and the limit of critical heat flux that sets the acceptance criteria for the study. The objective of the study is to demonstrate that the control rods will remain cooled at powers representative of those anticipated for restart of the reactor. The study accomplishes this objective with a very tractable simplified analysis for the modest restart power. In addition, a best-estimate calculation is performed, and the results are compared to results from sub-scale scoping experiments. 5 refs.

Easterling, T.C.; Hightower, N.T. (Westinghouse Savannah River Co., Aiken, SC (United States)); Smith, D.C.; Amos, C.N. (Science Applications International Corp., Albuquerque, NM (United States))

1992-01-01

371

Predicted irradiation behavior of U sub 3 O sub 8 -Al dispersion fuels for production reactor applications  

SciTech Connect

Candidate fuels for the new heavy-water production reactor include uranium/aluminum alloy and U{sub 3}O{sub 8}--Al dispersion fuels. The U{sub 3}O{sub 8}--Al dispersion fuel would make possible higher uranium loadings and would facilitate uranium recycle. Research efforts on U{sub 3}O{sub 8}--Al fuel include in-pile irradiation studies and development of analytical tools to characterize the behavior of dispersion fuels at high-burnup. In this paper the irradiation performance of U{sub 3}O{sub 8}--Al is assessed using the mechanistic Dispersion Analysis Research Tool (DART) code. Predictions of fuel swelling and alteration of thermal conductivity are presented and compared with experimental data. Calculational results indicate good agreement with available data where the effects of as-fabricated porosity and U{sub 3}O{sub 8}--Al oxygen exchange reactions are shown to exert a controlling influence on irradiation behavior. The DART code is judged to be a useful tool for assessing U{sub 3}O{sub 8}--Al performance over a wide range of irradiation conditions. 8 refs., 8 figs., 1 tab.

Cronenberg, A.W. (Engineering Science and Analysis, Albuquerque, NM (USA)); Rest, J. (Argonne National Lab., IL (USA)); Hyder, M.L.; Morin, J.P.; Peacock, H.B. (Westinghouse Savannah River Co., Aiken, SC (USA))

1990-01-01

372

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

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.

Dale, M.C.; Lei, Shuiwang; Zhou, Chongde

1995-10-01

373

Accumulation of radioactive corrosion products on steel surfaces of VVER type nuclear reactors. I. 110mAg  

NASA Astrophysics Data System (ADS)

Formation, presence and deposition of corrosion product radionuclides (such as 60Co, 51Cr, 54Mn, 59Fe and/or 110mAg) in the primary circuits of water-cooled nuclear reactors (PWRs) throw many obstacles in the way of normal operation. During the course of the work presented in this series, accumulations of such radionuclides have been studied at austenitic stainless steel type 08X18H10T (GOST 5632-61) surfaces (this austenitic stainless steel corresponds to AISI 321). Comparative experiments have been performed on magnetite-covered carbon steel (both materials are frequently used in some Soviet VVER type PWRs). For these laboratory-scale investigations a combination of the in situ radiotracer `thin gap' method and voltammetry is considered to be a powerful tool due to its high sensitivity towards the detection of the submonolayer coverages of corrosion product radionuclides. An independent technique (XPS) is also used to characterize the depth distribution and chemical state of various contaminants in the passive layer formed on austenitic stainless steel. In the first part of the series the accumulation of 110mAg has been investigated. Potential dependent sorption of Ag + ions (cementation) is found to be the predominant process on austenitic steel, while in the case of magnetite-covered carbon steel the silver species are mainly depleted in the form of Ag 2O. The XPS depth profile of Ag gives an evidence about the embedding of metallic silver into the entire passive layer of the austenitic stainless steel studied.

Hirschberg, Gábor; Baradlai, Pál; Varga, Kálmán; Myburg, Gerrit; Schunk, János; Tilky, Péter; Stoddart, Paul

374

Biodegradation of the herbicide propanil, and its 3,4-dichloroaniline by-product in a continuously operated biofilm reactor.  

PubMed

The persistence of propanil in soil and aquatic environments along with the possible accumulation of toxic degradation products, such as chloroanilines, is of environmental concern. In this work, a continuous small-scale bioprocess to degrade the herbicide propanil, its main catabolic by-product, 3,4-dichloroaniline (3,4-DCA), and the herbicide adjuvants is carried out. A microbial consortium, constituted by nine bacterial genera, was selected. The isolated strains, identified by amplification and sequencing of their 16S rDNA, were: Acidovorax sp., Luteibacter (rhizovicinus), Xanthomonas sp., Flavobacterium sp., Variovorax sp., Acinetobacter (calcoaceticus), Pseudomonas sp., Rhodococcus sp., and Kocuria sp. The ability of the microbial consortium to degrade the herbicide was evaluated in a biofilm reactor at propanil loading rates ranging from 1.9 to 36.8 mg L(-1) h(-1). Complete removal of propanil, 3,4-DCA, chemical oxygen demand and total organic carbon was obtained at propanil loading rates up to 24.9 mg L(-1) h(-1). At higher loading rates, the removal efficiencies decayed. Four of the identified strains could grow individually in propanil, and 3,4-DCA: Pseudomonas sp., Acinetobacter calcoaceticus, Rhodococcus sp., and Xanthomonas sp. The Kokuria strain grew on 3,4-DCA, but not on propanil. The first three bacteria have been related to biodegradation of phenyl urea herbicides or chlorinated anilines. Although some strains of the genera Xanthomonas and Kocuria have a role in the biodegradation of several xenobiotic compounds, as far as we know, there are no reports about degradation of propanil by Xanthomonas or 3,4-DCA by Kocuria species. PMID:23117676

Herrera-González, Víctor Emmanuel; Ruiz-Ordaz, Nora; Galíndez-Mayer, Juvencio; Juárez-Ramírez, Cleotilde; Santoyo-Tepole, Fortunata; Montiel, Erick Marrón

2013-03-01

375

Computational prediction of dust production in graphite moderated pebble bed reactors  

NASA Astrophysics Data System (ADS)

The scope of the work reported here, which is the computational study of graphite wear behavior, supports the Nuclear Engineering University Programs project "Experimental Study and Computational Simulations of Key Pebble Bed Thermomechanics Issues for Design and Safety" funded by the US Department of Energy. In this work, modeling and simulating the contact mechanics, as anticipated in a PBR configuration, is carried out for the purpose of assessing the amount of dust generated during a full power operation year of a PBR. A methodology that encompasses finite element analysis (FEA) and micromechanics of wear is developed to address the issue of dust production and its quantification. Particularly, the phenomenon of wear and change of its rate with sliding length is the main focus of this dissertation. This work studies the wear properties of graphite by simulating pebble motion and interactions of a specific type of nuclear grade graphite, IG-11. This study consists of two perspectives: macroscale stress analysis and microscale analysis of wear mechanisms. The first is a set of FEA simulations considering pebble-pebble frictional contact. In these simulations, the mass of generated graphite particulates due to frictional contact is calculated by incorporating FEA results into Archard's equation, which is a linear correlation between wear mass and wear length. However, the experimental data by Johnson, University of Idaho, revealed that the wear rate of graphite decreases with sliding length. This is because the surfaces of the graphite pebbles become smoother over time, which results in a gradual decrease in wear rate. In order to address the change in wear rate, a more detailed analysis of wear mechanisms at room temperature is presented. In this microscale study, the wear behavior of graphite at the asperity level is studied by simulating the contact between asperities of facing surfaces. By introducing the effect of asperity removal on wear rate, a nonlinear wear rate is obtained. The nonlinear wear law proposed in this study serves as a model to predict the effect of changing surface topology on the wear behavior of graphite. This tribological model is valid for applications where mass removal is in the form of powder formation rather than flake or chip formation. Dust explosion tests performed by Poulsen, University of Idaho, under the same project, have revealed that the smallest amount of graphite dust mass that can lead to explosions is three orders of magnitudes larger than the maximum amount predicted to be generated in the present work. Therefore, it is concluded that pebble-pebble frictional contact is not a plausible source of dust generation and subsequent explosion hazard under normal operating conditions or even accident scenarios. (Abstract shortened by UMI.)

Rostamian, Maziar

376

Potential role of the Fast Flux Test Facility and the advanced test reactor in the U.S. tritium production system  

SciTech Connect

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.

Dautel, W.A.

1996-10-01

377

Conversion of high carbon refinery by-products: Mechanical completion and start-up new transport reactor system. Third quarterly technical progress report, April--June 1995  

SciTech Connect

The objective of the study is to demonstrate that a partial oxidation system, which utilizes a transport reactor, is a viable means of converting refinery wastes, by-products, and other low-value materials into valuable products. The primary product would be a high quality fuel gas, which could also be used as a source of hydrogen. The concept involves subjecting the hydrocarbon feed material to pyrolysis and steam gasification in a circulating bed of solids. Carbon residue formed during pyrolysis, as well as metals in the feed, are captured by the circulating solids, which are returned to the bottom of the transport reactor. Air or oxygen is introduced in this lower zone and sufficient carbon is burned, sub-stoichiometrically, to provide the necessary heat for the endothermic pyrolysis and gasification reactions. The hot solids and gases leaving this zone pass upward to contact the feed material and continue the partial oxidation process. To date, the project has gone through essentially three phases of testing, with the third phase still in progress. Initial testing was.done in a bench-scale reactor unit (BRU), a dense phase fluidized bed semi-batch reactor. These tests were of a scoping nature, to identify system parameters for subsequent tests. The second phase consisted of tests in the Transport Reactor Test Unit (TRTU), a continuous flow pilot plant transport system which can be run either in the pyrolysis mode, or combustion mode, or as a fully integrated partial oxidation system. However, owing to severe operational problems, integrated operation with a highly coking feed could not be achieved, and only a limited number of pyrolysis/gasification runs were completed. As a result, Kellogg decided to build a new transport pilot plant facility specifically designed for handling heavy hydrocarbon feeds.

NONE

1995-09-01

378

Fission product retention in newly discovered organic-rich natural fission reactors at Oklo and Bangombe, Gabon  

Microsoft Academic Search

The discovery of naturally occurring fission reactors in the rock strata of the Paleoproterozoic Francevillian Basin in the Republic of Gabon in equatorial West Africa led to several programs to define migration and\\/or retention of uranium and fissiogenic isotopes from\\/in the natural reactor zones. Although much understanding has been gained, new insight is needed regarding the chemical and physical parameters

B. Nagy; M. J. Rigali

1993-01-01

379

Numerical results of production test IP326-I, Low-flow calibration tests at B, D, F, and H Reactors  

Microsoft Academic Search

Recent reviews of the last-ditch water backup system at the old reactors had shown that complete adequacy could not be demonstrated at all of the reactors under all conditions. However, these conclusions were based in part on conservative calculations using basic data with a sizeable amount of possible error. Subsequently, recommendations were made to run several tests which would increase

1960-01-01

380

Enzymatic biodiesel production kinetics using co-solvent and an anhydrous medium: a strategy to improve lipase performance in a semi-continuous reactor.  

PubMed

Enzymatic biodiesel production kinetics under previously optimized conditions were investigated. Waste frying oil (WFO) was used as the raw material, Novozym 435 as catalyst, methanol as acyl acceptor and tert-butanol as co-solvent. To investigate pure transesterification kinetics improving product properties, 3? molecular sieves were incorporated into the reaction to provide an anhydrous medium avoiding the side reactions of hydrolysis and esterification. The effects of either WFO or methanol on the reaction rate were analyzed separately. The reaction was described by a Ping Pong mechanism and competitive inhibition by methanol. The results obtained in the kinetics study were applied in the operation of a semi-continuous reactor for biodiesel production. The operational conditions of each reaction cycle were: methanol-to-oil ratio 8/1 (mol/mol), 15% (wt) Novozym 435, 0.75% (v/v) of tert-butanol, 44.5°C, 200rpm and 4h of reaction time. The enzymes were successively reused by remaining in the reactor during all the cycles. Under these conditions, biodiesel production yields higher than 80% over 7 reaction cycles were observed. Both the kinetics study and the reactor operation showed that Novozym 435 was not inhibited at high methanol concentrations and that the kinetics of the proposed enzymatic process could be comparable to the conventional chemical process. PMID:24792529

Azócar, Laura; Navia, Rodrigo; Beroiz, Leticia; Jeison, David; Ciudad, Gustavo

2014-09-25

381

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)

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.

Schicks, Judith Maria; Spangenberg, Erik; Giese, Ronny; Heeschen, Katja; Priegnitz, Mike; Luzi-Helbing, Manja; Thaler, Jan; Abendroth, Sven; Klump, Jens

2014-05-01

382

Hydrogen production with high yield and high evolution rate by self-flocculated cells of Enterobacter aerogenes in a packed-bed reactor  

Microsoft Academic Search

Continuous hydrogen gas evolution by self-flocculated cells of Enterobacter aerogenes, a natural isolate HU-101 and its mutant AY-2, was performed in a packed-bed reactor under glucose-limiting conditions in\\u000a a minimal medium. The flocs that formed during the continuous culture were retained even when the dilution rate was increased\\u000a to 0.9?h?1. The H2 production rate increased linearly with increases in the

M. A. Rachman; Y. Nakashimada; T. Kakizono; N. Nishio

1998-01-01

383

Modeling and simulation of an integrated multi-shell fixed bed membrane reactor with well-mixed catalyst pattern for production of styrene and cyclohexane  

Microsoft Academic Search

A rigorous two-dimensional steady state mathematical model based on the dusty gas model is implemented to investigate the performance of a bench-scale integrated multi-shell fixed bed membrane reactor with well-mixed catalyst pattern for simultaneous production of styrene and cyclohexane. Since the styrene producing reaction is equilibrium limited, significant displacement of the thermodynamic equilibrium is achieved by three simultaneous actions of

M. E. E. Abashar

2011-01-01

384

Ethanol Production from Rice-Straw Hydrolysate Using Zymomonas Mobilis in a Continuous Fluidized-Bed Reactor (FBR)  

SciTech Connect

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.

deJesus, D.; Nghiem, N.P.

2001-01-01

385

Product Selectivity Control and Organic Oxygenate Pathways from Partial Oxidation of Methane in a Silent Electric Discharge Reactor  

E-print Network

* Institute for Gas Utilization Technologies and School of Chemical Engineering and Materials Science), allowing the organic oxygenates to condense on the plate itself inside the reactor. The results show

Mallinson, Richard

386

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

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

Freels, James D [ORNL] [ORNL; Jain, Prashant K [ORNL] [ORNL; Hobbs, Randy W [ORNL] [ORNL

2012-01-01

387

Fission Product Impact Reduction via Protracted In-core Retention in Very High Temperature Reactor (VHTR) Transmutation Scenarios  

E-print Network

Oak Ridge National Laboratory OTOC Once-Through-and-Out Cycle P&T Partitioning and Transmutation PWR Pressurized Water Reactor SNF Spent Nuclear Fuel THTR Thorium High Temperature Reactor TRISO Tri-structural Isotropic TRU Transuranium Nuclide... and thermal spectrum ?.. 77 17 Key focus of Chapter IV ???????????????????? 86 18 Fuel assembly block?????????????????????.... 88 19 Fuel assembly block dimensions????????????????? 89 20 TRISO fuel structure?????????????????????.. 92 21...

Alajo, Ayodeji Babatunde

2011-08-08

388

Hydrogen production by steam-gasification of petroleum coke using concentrated solar power—III. Reactor experimentation with slurry feeding  

Microsoft Academic Search

We report on the experimental evaluation of a 5kW solar chemical reactor for the steam-gasification of petcoke, carried out in a high-flux solar furnace. A petcoke–water slurry was continuously injected into a solar cavity-receiver to create a vortex flow directly exposed to concentrated solar radiation. For a nominal reactor temperature of 1500K, a water–petcoke molar ratio of 4.8, and a

A. Z’Graggen; P. Haueter; G. Maag; A. Vidal; M. Romero; A. Steinfeld

2007-01-01

389

Comparision of real waste (MSW and MPW) pyrolysis in batch reactor over different catalysts. Part I: product yields, gas and pyrolysis oil properties.  

PubMed

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, ?-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

Ate?, Funda; Miskolczi, Norbert; Borsodi, Nikolett

2013-04-01

390

Mathematical simulation of fixed bed reactors  

Microsoft Academic Search

Anaerobic digestion of agricultural wastes using conventional stirred-reactor technology has been unsuccessful in treatment of dilute waste streams. The development of ''fixed bed'' anaerobic reactors has provided an effective method of utilizing dilute waste for methane production. Fixed bed reactors, or anaerobic filters, are unique among anaerobic reactor designs in that a fixed support medium is placed inside the reactor

J. P. Bolte; R. A. Nordstedt; M. V. Thomas

1983-01-01

391

Robust Low-Cost Water-Gas Shift Membrane Reactor for High-Purity Hydrogen Production form Coal-Derived Syngas  

SciTech Connect

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.

James Torkelson; Neng Ye; Zhijiang Li; Decio Coutinho; Mark Fokema

2008-05-31

392

Growth and characterization of high-efficiency InGaN MQW blue and green LEDs from large-scale-production MOCVD reactors  

NASA Astrophysics Data System (ADS)

As more advances are made in the performance of GaN-based devices, a trend toward the use of large scale MOCVD reactors for epitaxial growth of GaN-based device structures is clear. In this paper we describe the use of Emcore's SpectraBlueTM reactor for large-scale manufacturing of Blue and Green LEDs. The high throughput growth of GaN based LEDs is demonstrated without compromising LED uniformity or overall performance. In-situ control of key parameters critical to the production of high quality LEDs, such as buffer layer growth is now feasible using in-situ reflectance spectroscopy. Film properties as well as LED device performance are discussed.

Tran, Chuong A.; Karlicek, Robert F., Jr.; Brown, Michael G.; Eliashevich, Ivan; Gurary, Alexander; Stall, Richard A.

1999-04-01

393

Integrated polynomic growth parameter model for GaN/GaInN MQW structures for 6x2" and 11x2" mass production MOCVD reactors  

NASA Astrophysics Data System (ADS)

The growth conditions for GaN/GaInN MQW structures have been studied in detail on AIX 2000 HT G3 Planetary Reactors. Major process variables, such as precursor supply, growth time and growth temperature have been varied. To describe the dependencies of MQW growth a second order polynomic model has been developed. The average prediction error within the model limits is 2.8 nm emission wavelength, in the range of 400 to 490 nm. The linear effects of the major growth parameters have been quantified. Additionally, statistically significant curvature factors have been identified as the product of growth time and temperature, the square of the TMIn molar supply rate and the square of the growth time. To increase the system throughput for mass production applications the reactor geometry has been scaled up to 11x2" in the AIX 2400 HT G3 configuration recently. Numerical simulation of thermal field and decomposition chemistry has been performed for the new reactor set up. From the simulation results initial values for the respective process parameters have been chosen. The numerical growth parameter model has been transferred to the larger configuration and is verified with experimental results. Employing the 11x2' Planetary Reactor configuration an excellent on wafer uniformity of better than 0.2% (1 nm) standard deviation at 487 nm average peak wavelength has been shown. Wafer-to-wafer reproducibility has been demonstrated with a variation of 1.4 nm standard deviation and run-to-run with a variation of 0.25 nm standard deviation at an average wavelength of 470 nm for a full load of 11 wafers. The uniformities obtained are compared with results from the 6x2" configuration.

Schoen, Oliver; Protzmann, Harry; Luenenbuerger, Markus; Wachtendorf, Bernd; Schoettker, Bernd; Heuken, Michael

2002-06-01

394

A spectroscopic study of ethylene destruction and by-product generation using a three-stage atmospheric packed-bed plasma reactor  

NASA Astrophysics Data System (ADS)

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, CO2, O3, NO2, N2O, HCN, H2O, HNO3, CH2O, and CH2O2 has been monitored. The concentrations of the by-products range between 5 ppm, in the case of NO2, and 1200 ppm, for H2O. 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 C2H4 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-1. The value of the characteristic energy ?, characterizing the energy efficiency of the ethylene destruction in the reactor, was found to be 330 J l-1. It was proven that the application of three reactor stages suppresses essentially the production of harmful by-products as formaldehyde, formic acid, and NO2 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 (RF(C2H4) = 5.5 × 1019 molecules J-1) and conversion efficiencies to the produced molecular species (RC = (0.1-3) × 1016 molecules J-1) on the discharge conditions could be estimated in the multistage plasma reactor.

Hübner, M.; Guaitella, O.; Rousseau, A.; Röpcke, J.

2013-07-01

395

A spectroscopic study of ethylene destruction and by-product generation using a three-stage atmospheric packed-bed plasma reactor  

SciTech Connect

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.

Huebner, M.; Roepcke, J. [INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Guaitella, O.; Rousseau, A. [LPP, Ecole Polytechnique, UPMC, Universite Paris Sud-11, CNRS, Palaiseau (France)

2013-07-21

396

PRODUCTION OF FERTILIZER IN A MULTIPURPOSE ATOMIC POWER REACTOR COMPLEX FOR DISTILLATION OF SEA WATER: A SURVEY  

Microsoft Academic Search

4 = e to determine the feasibility of producing large amounts ; of nitrogen, phosphate, and potassium fertilizers with the cheap power produced ; from a large atomic reactor. The optimum combination was a multipurpose plant to ; produce fresh water from sea water by distillation and fertilizer from the air, ; sea, and phosphate rock. No other raw materials

1963-01-01

397

Process for separately recovering uranium, transuranium elements, and fission products of uranium from atomic reactor fuel. [electrolytic extraction  

Microsoft Academic Search

Spent reactor fuel elements are dissolved in dilute nitric acid. After addition of acetic acid as a complexing agent, the nitric acid is partly decomposed and the mixture subjected to electrolysis while a carrier liquid, which may be dilute acetic acid or a dilute mixture of acetic acid and nitric acid is caused to flow in the electric field between

A. L. Balal; K. Metscher; B. Muehlig; C. Reichmuth; B. Schwarz; K. E. Zimen

1976-01-01

398

Experimental investigations on reactor scale-up and optimisation of product quality in pyrolysis of shredder waste  

Microsoft Academic Search

Shredder waste is the light fraction separated from automotive shredder scrap by air classifiers and contains mainly plastics. The present work focuses on pyrolysis of shredder waste as a possible way for chemical recycling of plastic wastes and deals with the technical requirements for an industrial application. Pyrolysis experiments have been conducted in two different laboratory reactors at high and

Ch Pasel; W Wanzl

2003-01-01

399

Hydrogen production enhancement and the effect of passive mixing using flow disturbers in a steam-reforming reactor  

NASA Astrophysics Data System (ADS)

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.

Liao, Chang-Hsien

400

STUDY OF 40 MW PRESSURIZED WATER, BOILING WATER, AND ORGANIC MODERATED REACTORS FOR PRODUCTION OF PROCESS STEAM  

Microsoft Academic Search

The study efforts were toward the creation of a reactor design for each ; of the three types and the development of each concept to a point where the range ; of costs could be established. The studies presented have high burnup cores of ; low enrichment in an effort to minimize fuel costs. Of the three designs ; presented

L. E. Link; R. H. Armstrong; C. R. Breden; R. J. Gariboldi; L. E. Genens; C. N. Kelber; P. H. Kier; V. M. Kolba; E. L. Martinec; D. R. Patterson; R. R. Rohde; A. D. Rossin

1959-01-01

401

Catalytic Cracking of Cottonseed Oil on Fixed-fluidized Bed Reactor: Product Distribution and Analysis of the Gasoline Fraction  

Microsoft Academic Search

Gasoline samples resulting from cottonseed oil catalytic cracking on a fixed-fluidized bed were analyzed to give the carbon number distribution of paraffinic, isoparaffinic, olefinic, naphthenic, and aromatic components using PIONA analysis. Cottonseed oil catalytic cracking was studied on a fixed-fluidized bed reactor under atmospheric pressure in order to analyze temperature influence on the gasoline composition. Cracking temperatures were from 430

H. Li; B. X. Shen; J. C. Kabalu; N. Mominou

2010-01-01

402

Vapor recovery reactor in carbothermic aluminum production: model verification and sensitivity study for a fixed bed column  

Microsoft Academic Search

In this paper we develop a distributed parameter model for a fixed bed vapor recovery reactor (VRR) in a carbothermic aluminum process. The model we develop for the reaction mechanism is based on the mass transfer limited (shrinking core) reaction scheme. This model is combined with the partial differential equations (PDEs) describing the component mass and energy balances. The system

Vianey Garcia-Osorio; B. Erik Ydstie

2004-01-01

403

Influence of carbon sources and C/N ratio on EPS production in anaerobic sequencing batch biofilm reactors for wastewater treatment.  

PubMed

The objective of this work was to evaluate the influence of different carbon sources and the carbon/nitrogen ratio (C/N) on the production and main composition of insoluble extracellular polymers (EPS) produced in an anaerobic sequencing batch biofilm reactor (ASBBR) with immobilized biomass in polyurethane foam. The yield of EPS was 23.6 mg/g carbon, 13.3 mg/g carbon, 9.0 mg/g carbon and 1.4 mg/g carbon when the reactor was fed with glucose, soybean oil, fat acids, and meat extract, respectively. The yield of EPS decreased from 23.6 to 2.6 mg/g carbon as the C/N ratio was decreased from 13.6 to 3.4 gC/gN, using glucose as carbon source. EPS production was not observed under strict anaerobic conditions. The results suggest that the carbon source, microaerophilic conditions and high C/N ratio favor EPS production in the ASBBR used for wastewater treatment. Cellulose was the main exopolysaccharide observed in all experimental conditions. PMID:19783138

Miqueleto, A P; Dolosic, C C; Pozzi, E; Foresti, E; Zaiat, M

2010-02-01

404

Preliminary Results of an On-Line, Multi-Spectrometer Fission Product Monitoring System to Support Advanced Gas Reactor Fuel Testing and Qualification in the Advanced Test Reactor at the Idaho National Laboratory  

SciTech Connect

The Advanced Gas Reactor -1 (AGR-1) experiment is the first experiment in a series of eight separate low enriched uranium (LEU) oxycarbide (UCO) tri-isotropic (TRISO) particle fuel (in compact form) experiments scheduled for placement in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The experiment began irradiation in the ATR with a cycle that reached full power on December 26, 2006 and will continue irradiation for about 2.5 years. During this time six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The goals of the irradiation experiment is to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. This paper presents the preliminary test details of the fuel performance, as measured by the control and acquisition software.

Dawn M. Scates; John K. Hartwell; John B. Walter; Mark W. Drigert

2007-10-01

405

Environmental Monitoring Plan, United States Department of Energy, Richland Operations Office. Revision 1  

SciTech Connect

This report describes environmental monitoring activities at Hanford Reservation. Attention is focused on effluent monitoring and environmental surveillance. All Hanford contractors reviewed potential sources of contamination. A facility effluent monitoring plan was written for each facility with the potential to release significant quantities of hazardous materials, addressing both radiological and nonradiological effluent monitoring. The environmental surveillance program assesses onsite and offsite environmental impacts and offsite human health exposures. The program monitors air, surface water, sediment, agricultural products, vegetation, soil, and wildlife. In addition, independent onsite surveillance is conducted to evaluate the effectiveness of Hanford Site effluent controls in order to comply with applicable environmental standards and regulations.

Not Available

1994-11-09

406

Confirmatory radiological survey for the 190-C Main Pumphouse Facility decommissioning at the Hanford Site, Richland, Washington  

SciTech Connect

An independent assessment of remedial action activities at the 190-C Main Pumphouse Facility at the Hanford Site, Richland, Washington has been accomplished by the Oak Ridge National Laboratory Environmental Assessments Group. The purpose of the assessment was to confirm the site`s compliance with DOE applicable guidelines and provide independent measurements of the activity levels in the 190-C trenches and 105-C process water tunnels. The assessment included reviews of the Decontamination and Decommissioning Plan and data provided in the pre- and post-remedial action surveys. An on-site independent verification survey of the facility was conducted during the period of November 19--21, 1996. The independent verification survey included beta and gamma scans, smears for removable contamination, and direct measurements for beta-gamma activity in the trenches and tunnels. The same measurements and scans, with the addition of alpha measurements, were performed on the floor in the filter repair confinement area. The facility was also spot-checked for direct alpha and beta-gamma activity.

Coleman, R.L. [Oak Ridge National Lab., TN (United States); Forbes, G.H. [Oak Ridge National Lab., Grand Junction, CO (United States). Environmental Technology Section

1997-06-01

407

Lipase-catalyzed reaction in the packed-bed reactor with continuous extraction column to overcome a product inhibition  

Microsoft Academic Search

The resolution of rac-?-methyl-?-propiothiolactone (rac-MPTL) was performed in a packed-bed reactor (PBR) using Pseudomonas cepacia lipase (PCL) in organic media to produce enantiopure (R)-MPTL. By comparing enzyme stability of three enzyme forms, i.e. commercial PCL powder, Celite-immobilized PCL, and cross-linked enzyme crystals of PCL (CLECs-PCL), Celite-immobilized PCL was chosen for the construction of PBR because of its comparable stability to

Sekyoo Jeong; Bum-Yeol Hwang; Juhan Kim; Byung-Gee Kim

2000-01-01

408

Construction and operation of a fibrous bed reactor with immobilized lactonase for efficient production of ( R)-?-hydroxy-?-butyrolactone  

Microsoft Academic Search

Optically active (R)-?-hydroxy-?-butyrolactone (R-HBL) was produced via enantioselective hydrolysis of racemic HBL using a lactonase extracted from Fusarium proliferatum ECU2002 (FPL). Different carriers were examined for immobilizing FPL and the highest activity was observed when the enzyme was adsorbed onto cotton cloth followed by cross-linking with glutaraldehyde. A fibrous bed reactor (FBR) was constructed by packing a piece of cotton

Xian Zhang; Jian-He Xu; Dian-Hua Liu; Jiang Pan; Bing Chen

2010-01-01

409

Continuous O 2 CO 2 production using a Co-based oxygen carrier in two parallel fixed-bed reactors  

Microsoft Academic Search

Oxygen-enriched carbon dioxide stream with oxygen concentration higher than 20 vol% was produced continuously by using a Co-based\\u000a oxygen carrier packed in two parallel fixed-bed reactors operated in a cyclic manner. Oxygen was absorbed by the oxygen carrier\\u000a with air being fed. An oxygen-enriched carbon dioxide stream was obtained when the fixed-bed was regenerated with carbon dioxide\\u000a as a purge

Teng Zhang; Zhenshan Li; Ningsheng Cai

2009-01-01

410

Determination of Optimal Process Flowrates and Reactor Design for Autothermal Hydrogen Production in a Heat-Integrated Ceramic Microchannel Network  

E-print Network

of Committee, Benjamin Wilhite Committee Members, Dan Shantz Molly Gentleman Head of Department, Charles Glover May 2012 Major Subject: Chemical Engineering iii ABSTRACT Determination of Optimal Process Flowrates and Reactor Design... Wilhite, for his invaluable motivation, guidance and for being extremely patient throughout the course of my research. I would also like to thank Dr. Dan Shantz and Dr. Molly Gentleman for acting as members of my thesis committee and their valuable time...

Damodharan, Shalini

2012-07-16

411

Solvent refined coal reactor quench system  

DOEpatents

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.

Thorogood, Robert M. (Macungie, PA)

1983-01-01

412

Solvent refined coal reactor quench system  

DOEpatents

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.

Thorogood, R.M.

1983-11-08

413

A safety assessment for proposed pump mixing operations to mitigate episodic gas releases in tank 241-SY-101: Hanford Site,Richland, Washington  

SciTech Connect

This safety assessment addresses each of the elements required for the proposed action to remove a slurry distributor and to install, operate, and remove a mixing pump in Tank 241-SY-101,which is located within the Hanford Site, Richland, Washington.The proposed action is required as part of an ongoing evaluation of various mitigation concepts developed to eliminate episodic gas releases that result in hydrogen concentrations in the tank dome space that exceed the lower flammability limit.

Lentsch, J.W.

1996-07-01

414

Safety assessment for proposed pump mixing operations to mitigate episodic gas releases in tank 241-101-SY: Hanford Site, Richland, Washington  

SciTech Connect

This safety assessment addresses each of the elements required for the proposed action to remove a slurry distributor and to install, operate, and remove a mixing pump in Tank 241-SY-101, which is located within the Hanford Site, Richland, Washington. The proposed action is required as part of an ongoing evaluation of various mitigation concepts developed to eliminate episodic gas releases that result in hydrogen concentrations in the tank dome space that exceed the lower flammability limit.

Lentsch, J.W., Westinghouse Hanford

1996-05-16

415

Startup of the New 200 West Pump-and-Treat, Hanford Site, Richland, Washington - 13214  

SciTech Connect

On June 28, 2012, CH2M HILL Plateau Remediation Company (CHPRC) completed the construction and acceptance testing for a new 2,500 gallon-per-minute (gpm) pump-and-treat (P and T) system in the 200 West Area of the Hanford Site in Washington State. This system is designed to remove Tc-99, carbon tetrachloride, trichloroethene (TCE), nitrate, and total and hexavalent chromium from groundwater using ion exchange, anoxic and aerobic bioreactors, and air stripping. The system will eventually remove uranium from groundwater using ion exchange as well. The startup of the P and T system is important because it will ensure that contaminants from the 200 West Area never reach the Columbia River. When fully operational, the 200 West P and T will include approximately 23 extraction wells and 21 injection wells. The extraction wells are 8 inches in diameter, are completed with well screens 100 feet or more in length, and are distributed throughout the central portion of the 5-square-mile carbon tetrachloride plume. The injection wells are also 8 inches in diameter and are installed up-gradient of the plumes to recharge the aquifer and down-gradient of the plumes for flow-path control. Groundwater in the 200 West Area is approximately 250 feet below ground surface, and the aquifer is 200 feet or more in thickness. All of the contaminants (except nitrate) are found within the perimeter of the carbon tetrachloride plume and occur at various depths throughout the aquifer. The 200 West P and T consists of two separate buildings to conduct groundwater treatment. The RAD building contains an ion exchange system to remove Tc-99 from groundwater at a maximum flow rate of 600 gpm. The RAD building only accepts water from those extraction wells showing elevated Tc-99 concentrations. Groundwater initially fills an influent tank, is then pumped through particulate filters (to remove suspended materials), and then passes through two parallel treatment trains containing Purolite{sup R} A530E resin (which has been proven effective in removing Tc-99). The water is then transferred to the biological treatment building for further treatment. When the lead vessel in each of the two treatment trains becomes fully loaded with Tc-99, the Purolite A530E resin is transferred to a separate tank where it is heated to 160 deg. F to remove volatile organics prior to disposal at the Environmental Restoration Disposal Facility. The biological treatment building has a maximum flow capacity of 2,500 gpm. Groundwater from the nonradiological extraction wells and treated groundwater from the RAD building are initially pumped into an equalization tank and then into two parallel fluidized bed reactors (FBRs). The FBRs contain granulated activated carbon in suspension for microbes to populate, a carbon-based food source for the microbes to eat (e.g., MicroCg{sup TM}, molasses, or sodium lactate), and nitrate for the microbes to breathe (represents 'anoxic' conditions that contain little or no dissolved oxygen). The FBRs are maintained at a temperature between 55 deg. F and 90 deg. F, and at a pH between 6.5 and 6.8, to maximize microbial growth. The FBRs break down the nitrate, reduce the hexavalent chromium to trivalent chromium, and break down a good portion of the carbon tetrachloride and TCE. From the FBRs, groundwater is pumped through a carbon separation tank, then through a splitter box that divides the water evenly between four membrane bioreactors (MBRs) that further break down the contaminants. The MBRs have aeration capacity to provide sufficient oxygen for maintaining the aerobic biological process. The MBRs use submerged membranes for filtration. Vertically strung fibers are found in the membrane zone where a vacuum draws water through tiny pores in the fibers. The liquid is then pumped to air strippers to remove any volatile organics that have passed through the bioreactors. Solids from the MBRs are pumped to rotary drum thickeners and centrifuges for dewatering prior to lime being added to kill the bacteria and control odor. The conditioned sludge is then

Byrnes, Mark E. [CH2M HILL Plateau Remediation Company, Richland, Washington (United States)] [CH2M HILL Plateau Remediation Company, Richland, Washington (United States); Simmons, Sally [Fluor Federal Services, Richland, Washington (United States)] [Fluor Federal Services, Richland, Washington (United States); Morse, John [U.S. Department of Energy, Richland Operations Office, Richland, Washington (United States)] [U.S. Department of Energy, Richland Operations Office, Richland, Washington (United States)

2013-07-01

416

Coenzyme Q(10) production by immobilized Sphingomonas sp. ZUTE03 via a conversion-extraction coupled process in a three-phase fluidized bed reactor.  

PubMed

A three-phase fluidized bed reactor (TPFBR) was designed to evaluate the potential of CoQ(10) production by gel-entrapped Sphingomonas sp. ZUTE03 via a conversion-extract coupled process. In the reactor, the CoQ(10) yield reached 46.99 mg/L after 8 h of conversion; a high-level yield of about 45 mg/L was maintained even after 15 repetitions (8 h/batch). To fully utilize the residual precursor (para-hydroxybenzoic acid, PHB) in the aqueous phase, the organic phase was replaced with new solution containing 70 mg/L solanesol for each 8 h batch. The CoQ(10) yield of each batch was maintained at a level of about 43 mg/L until the PHB ran out. When solid solanesol was fed to the organic phase for every 8 h batch, CoQ(10) could accumulate and reach a yield of 171.52 mg/L. When solid solanesol and PHB were fed to the conversion system after every 8 h batch, the CoQ(10) yield reached 441.65 mg/L in the organic phase after 20 repetitions, suggesting that the conversion-extract coupled process could enhance CoQ(10) production in the TPFBR. PMID:22226200

Qiu, Lequan; Ding, Hanbing; Wang, Weijian; Kong, Zhuoyi; Li, Xuanzhen; Shi, Yuping; Zhong, Weihong

2012-02-10

417

Anaerobic digestion as final step of a cellulosic ethanol biorefinery: Biogas production from fermentation effluent in a UASB reactor-pilot-scale results.  

PubMed

In order to lower the costs for second generation bioethanol from lignocellulosic biomass anaerobic digestion of the effluent from ethanol fermentation was implemented using an upflow anaerobic sludge blanket (UASB) reactor system in a pilot-scale biorefinery plant. Both thermophilic (53 degrees C) and mesophilic (38 degrees C) operation of the UASB reactor was investigated. At an OLR of 3.5 kg-VS/(m(3) day) a methane yield of 340 L/kg-VS was achieved for thermophilic operation (53 degrees C) while 270 L/kg-VS was obtained under mesophilic conditions (38 degrees C). For loading rates higher than 5 kg-VS/(m(3) day) the methane yields were, however, higher under mesophilic conditions compared to thermophilic conditions. The conversion of dissolved organic matter (VS(diss)) was between 68% and 91%. The effluent from the ethanol fermentation showed no signs of toxicity to the anaerobic microorganisms. However, a high content of suspended matter reduced the degradation efficiency. The retention time of the anaerobic system could be reduced from 70 to 7 h by additional removal of suspended matter by clarification. Implementation of the biogas production from the fermentation effluent accounted for about 30% higher carbon utilization in the biorefinery compared to a system with only bioethanol production. PMID:20506521

Uellendahl, H; Ahring, B K

2010-09-01

418

Fiscal year 1996 U.S. Department of Energy, Richland Operations Office Site summary baseline  

SciTech Connect

The technical baseline is a hierarchical description of the Hanford Site cleanup mission. This technical baseline does not address the science, technology, or economic transition missions. It begins with a definition of the existing conditions at the Hanford Site, provides a description of the end product or mission accomplishments at completion, presents a statement of the major requirements and constraints that must be observed during the performance of the mission, and provides a statement of the top-level strategic approach to accomplish the mission. Mission-level interfaces are also described. This information is further defined hierarchically in increasing levels of detail. This definition is composed of the following major elements: functions that are key task descriptions; requirements that are the measurable standards to which the functions must be performed; architectures which are specific engineering solutions or systems that perform the functions described earlier; and verification ensuring the system satisfies the requirements and fulfills the functions. The above information is supplemented with the following: interface data; risk analyses and watch lists; assumptions; and required analyses.

Johndro-Collins, A.

1995-10-01

419

Environmental assessment for the relocation and storage of isotopic heat sources, Hanford Site, Richland, Washington  

SciTech Connect

As part of a bilateral agreement between the Federal Minister for Research and Technology of the Federal Republic of Germany (FRG) and the DOE, Pacific Northwest National Laboratory (PNNL) developed processes for the treatment and immobilization of high-level radioactive waste. One element of this bilateral agreement was the production of sealed isotopic heat sources. During the mid-1980s, 30 sealed isotopic heat sources were manufactured. The sources contain a total of approximately 8.3 million curies consisting predominantly of cesium-137 and strontium-90 with trace amounts of transuranic contamination. Currently, the sources are stored in A-Cell of the 324 Building. Intense radiation fields from the sources are causing the cell windows and equipment to deteriorate. Originally, it was not intended to store the isotopic heat sources for this length of time in A-cell. The 34 isotopic heat sources are classified as remote handled transuranic wastes. Thirty-one of the isotopic heat sources are sealed, and seals on the three remaining isotopic heat sources have not been verified. However, a decision has been made to place the remaining three isotopic heat sources in the CASTOR cask(s). The Washington State Department of Health (WDOH) has concurred that isotopic heat sources with verified seals or those placed into CASTOR cask(s) can be considered sealed (no potential to emit radioactive air emissions) and are exempt from WAC Chapter 246-247, Radiation Protection-Air Emissions.

NONE

1997-06-01

420

Environmental assessment for the resiting, construction, and operation of the Environmental and Molecular Sciences Laboratory at the Hanford Site, Richland, Washington  

SciTech Connect

This environmental assessment (EA) presents estimated environmental impacts from the resiting, construction, and operation of the US Department of Energy`s (DOE`s) Environmental and Molecular Sciences Laboratory (EMSL), which is proposed to be constructed and operated on land near the south boundary of the Hanford Site near Richland, Washington. The EMSL, if constructed, would be a modern research facility in which experimental, theoretical, and computational techniques can be focused on environmental restoration problems, such as the chemical and transport behavior of complex mixtures of contaminants in the environment. The EMSL design includes approximately 18,500 square meters (200,000 square feet) of floor space on a 12-hectare (30-acre) site. The proposed new site is located within the city limits of Richland in north Richland, at the south end of DOE`s 300 Area, on land to be deeded to the US by the Battelle Memorial Institute. Approximately 200 persons are expected to be employed in the EMSL and approximately 60 visiting scientists may be working in the EMSL at any given time. State-of-the-art equipment is expected to be installed and used in the EMSL. Small amounts of hazardous substances (chemicals and radionuclides) are expected to be used in experimental work in the EMSL.

Not Available

1994-07-01

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