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1

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

National Technical Information Service (NTIS)

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 n...

1997-01-01

2

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

3

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

4

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

5

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

6

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

7

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

8

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

9

Institutional Transformation at Richland College.  

ERIC Educational Resources Information Center

Describes strategic changes at Richland College including the consolidation and expansion of special programs through the Office of Academic Enrichment, and institutional improvements involving student learning undertaken during the process of re-accreditation. (EV)

Canham, Raymond P.; Lester, Carole N.

2003-01-01

10

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

11

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

12

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

13

Modular Helium Reactor for Hydrogen Production.  

National Technical Information Service (NTIS)

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 ...

A. Shenoy K. Schultz L. Brown M. Fukuie M. Richards

2006-01-01

14

New Production Reactor project-management plan  

Microsoft Academic Search

This document provides a project management plan for the first phase of a project to design and build a new production reactor (NPR) at SRP. The design of the NPR is based upon proven SRP heavy water reactor design, with several enhancements such as full containment, moderator detritiation, improved cooling, and modernized control rooms and instrumentation. The first phase of

F. J. McCrosson; L. Hibbard; M. R. Buckner

1982-01-01

15

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

16

Safe new reactor for radionuclide production  

SciTech Connect

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

Gray, P.L.

1995-02-15

17

Continuous ethanol production by immobilized yeast reactor  

Microsoft Academic Search

Saccharomyces cerevisiae yeast immobilized in calcium alginate gel beads was employed in packed-bed column reactors for continuous ethanol production from glucose or cane molasses, and for beer fermentation from barley malt wort. With properly balanced nutrient content or periodical regeneration of cells by nutrient addition and aeration, ethanol production could be maintained for several months. About 7 percent (w\\/v) ethanol

Yu-Yen Linko; P. Linko

1981-01-01

18

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

19

Radionuclide production using a fast flux reactor  

PubMed

The production of 89Sr, (32,33)P, 35S via the (n, p)-reaction, and 117mSn, 153Gd via the (n, gamma)-reaction using the BOR-60 fast flux reactor was experimentally studied. Test samples were irradiated in the active core of the BOR-60 reactor with fast neutron flux of 1 x 10(15) cm(-2) s(-1) for 40-100 effective days. Gadolinium-153 was produced in a radial blanket cell, characterized by a modified ("softened") neutron spectrum. Data on target materials, procedure of irradiated target reprocessing, radionuclide yield, and specific activity are summarized in the report. The results of the experiment showed that large-scale production of the radionuclides listed above is possible using a fast-flux reactor. PMID:11003527

Karelin; Efimov; Filimonov; Kuznetsov; Revyakin; Andreev; Zhemkov; Bukh; Lebedev; Spiridonov

2000-10-01

20

Hydrogen production using modular hellum reactor  

Microsoft Academic Search

The high-temperature characteristics of the Modular Helium Reactor (MHR) make it a strong candidate for the production of hydrogen using either thermochemical or high- temperature electrolysis (HTE) processes. Using heat from the MHR to drive a Sulfur-Iodine (SI) thermochemical hydrogen process has been the subject of a DOE sponsored Nuclear Engineering Research Initiative (NERI) project lead by General Atomics, with

A Shenoy; SM Mohsin Reza; Matt Richards; General Atomics

1996-01-01

21

Reactors Save Energy, Costs for Hydrogen Production  

NASA Technical Reports Server (NTRS)

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

2014-01-01

22

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

23

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

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.

Not Available

1991-04-01

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

Hydrogen Production Using the Modular Helium Reactor  

SciTech Connect

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

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

2005-05-01

26

Fusion reactors for hydrogen production via electrolysis  

NASA Astrophysics Data System (ADS)

The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of 50 to 70% are projected for fusion reactors using high temperature blankets.

Fillo, J. A.; Powell, J. R.; Steinberg, M.

27

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.

Kck, A.; Steinfeldt, M.; Prenzel, K.; Swiderek, P.; Gleich, A. v.; Thming, J.

2011-07-01

28

Reactivity analysis of solution reactors for medical-radioisotope production  

Microsoft Academic Search

One of the primary methods to produce medical isotopes, such as 99Mo, is by irradiation of uranium targets in heterogeneous reactors. Solution reactors present a potential alternative to produce medical isotopes. The medical isotope production reactor concept has been proposed to produce medical isotopes with lower uranium consumption and waste than the corresponding fuel consumption and waste in heterogeneous reactors.

Francisco J. Souto; Robert H. Kimpland

2004-01-01

29

Use of circulating solution reactors for production of radioisotopes  

Microsoft Academic Search

This paper presents results from a series of analyses aimed at investigating the use of circulating solution reactors for production of medical and other radioisotopes. To date, several options have been proposed and investigated. These alternatives include the use of the Annular Core Research Reactor facility at Sandia National Laboratories and the Medical Isotopes Production Reactor (MIPR) by Babcock and

C. R. Hills; A. S. Heger

1997-01-01

30

Fission product behavior distribution in the TMI-2 reactor building.  

National Technical Information Service (NTIS)

This paper summarizes the results of the examinations performed on samples from the reactor building surfaces and water and samples obtained from the reactor coolant system. The total quantities of fission products, fuel, and core material elements measur...

C. V. McIsaac R. Kohli R. S. Denning D. W. Akers

1988-01-01

31

High-productivity continuous biofilm reactor for butanol production  

Microsoft Academic Search

Corn steep liquor (CSL), a byproduct of the corn wet-milling process, was used in an immobilized cell continuous biofilm reactor\\u000a to replace the expensive P2 medium ingredients. The use of CSL resulted in the production of 6.29 g\\/L of total acetone-butanol-ethanol\\u000a (ABE) as compared with 6.86 g\\/L in a control experiment. These studies were performed at a dilution rate of

Nasib Qureshi; Patrick Karcher; Michael Cotta; Hans P. Blaschek

2004-01-01

32

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

33

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

34

Continuous ethanol production by immobilized yeast in a fluidized reactor  

Microsoft Academic Search

In order to minimize the adverse effect of CO2 gas in a packed bed immobilized yeast reactor, a fluidized bed reactor was used for the continuous production of ethanol from glucose. Immobilized yeast was prepared by entrapping whole cells of Saccharomyces cerevisiae within a Caalginate matrix. It was found that the efficiency of the ethanol production in a fluidized bed

Gyu Heon Cho; Cha Yong Choi; Yang Do Choi; Moon H. Han

1981-01-01

35

The effective management of medical isotope production in research reactors  

SciTech Connect

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

Drummond, D.T. (Nordion International, Incorporated, Kanata, Ontario (Canada))

1993-01-01

36

RICHLAND CREEK WILDERNESS STUDY AREA, ARKANSAS.  

USGS Publications Warehouse

The Richland Creek Wilderness Study Area covers an area of about 5 sq mi in parts of Newton and Searcy Counties, Arkansas. Geochemical studies of the outcropping rocks and stream sediments in the study area indicate that these rocks have little promise for the occurrence of metallic mineral resources. There is little promise for the occurrence of natural gas within the area because the Pennsylvanian age rocks have been breached by erosion and the other potential reservoir rocks were reported as dry. Some of the sandstone and limestone could be used for commercial purposes.

Haley, Boyd, R.; Stroud, Raymond, B.

1984-01-01

37

Aerosol reactor production of uniform submicron powders  

DOEpatents

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

Flagan, Richard C. (Pasadena, CA); Wu, Jin J. (Pasadena, CA)

1991-02-19

38

Aerosol reactor production of uniform submicron powders  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

39

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

Microsoft Academic Search

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

W. E. Cawley; R. P. Omberg

1982-01-01

40

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

DOEpatents

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

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

1982-08-19

41

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

SciTech Connect

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

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

1996-01-01

42

Reactor safety analysis computer program features that enhance user productivity  

SciTech Connect

This paper describes several design features of the MARY computer program that increase user productivity. The MARY program was used to analyze behavior of the Savannah River Site (SRS) K Reactor during postulated nuclear and thermal-hydraulic transients, such as overpower and underflow events, before K Reactor was placed in cold standby in 1993. These analyses provide the bases for portions of the accident chapter of the K-Reactor Safety Analysis Report.

Burnett, T.W.T. [Westinghouse Electric Corp., Pittsburgh, PA (United States); Cleaver, B.H. [ABB Government Services, Inc. (United States); Fields, C.C.; McKinney, J.S.; Wooten, L.A. [Westinghouse Savannah River Co., Aiken, SC (United States); Finfrock, S.H. [Westinghouse Hanford Co., Richland, WA (United States)

1993-09-01

43

Flat Plate Heat Exchangers for the New Production Reactor.  

National Technical Information Service (NTIS)

The New Production Reactor (NPR) will require heat exchangers (HX) as part of the ancillary equipment. The most common type of heat exchanger in the US is the shell and tube, the type presently in SRP reactor service. This type of design is the one that i...

R. S. Ondrejcin

1988-01-01

44

Small Reactor for Semiconductor Production by Neutron Transmutation Doping  

SciTech Connect

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

Obara, Toru; Hong, Liem Peng [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1-N1-19, Ookayama Meguro-ku, Tokyo 152-8550 (Japan)

2010-06-22

45

Savannah River Site production reactor safety analysis report. Vol XII.  

National Technical Information Service (NTIS)

The Savannah River Site Production Reactor Technical Specifications, while comprising a section of the SAR, are maintained as a separate document. Further information on the Technical Specifications can be obtained from WSRC-TS-10003, (open quotes)Savanna...

1996-01-01

46

Computed tomography of INEL New Production Reactor target compacts.  

National Technical Information Service (NTIS)

Gamma-ray computed tomography (CT) is a potentially powerful nondestructive method for assessing New Production Reactor (NPR) target compacts and assemblies at Idaho National Engineering Laboratory. These target compacts are made up of numerous compressed...

G. P. Roberson H. E. Martz D. R. Rikard L. O. Hester T. J. Roney

1993-01-01

47

A 5 MW TRIGA reactor design for radioisotope production  

SciTech Connect

The production and preparation of commercial-scale quantities of radioisotopes has become an important activity as their medical and industrial applications continue to expand. There are currently various large multipurpose research reactors capable of producing ample quantities of radioisotopes. These facilities, however, have many competing demands placed upon them by a wide variety of researchers and scientific programs which severely limit their radioisotope production capability. A demonstrated need has developed for a simpler reactor facility dedicated to the production of radioisotopes on a commercial basis. This smaller, dedicated reactor could provide continuous fission and activation product radioisotopes to meet commercial requirements for the foreseeable future. The design of a 5 MW TRIGA reactor facility, upgradeable to 10 MW, dedicated to the production of industrial and medical radioisotopes is discussed. A TRIGA reactor designed specifically for this purpose with its demonstrated long core life and simplicity of operation would translate into increased radioisotope production. As an example, a single TRIGA could supply the entire US needs for Mo-99. The facility is based on the experience gained by General Atomics in the design, installation, and construction of over 60 other TRIGAs over the past 35 years. The unique uranium-zirconium hydride fuel makes TRIGA reactors inexpensive to build and operate, reliable in their simplicity, highly flexible due to unique passive safety, and environmentally friendly because of minimal power requirements and long-lived fuel. (author)

Veca, Anthony R.; Whittemore, William L. [General Atomics, San Diego, CA (United States)

1994-07-01

48

Lactic Acid Production in a Mixed-Culture Biofilm Reactor  

PubMed Central

Novel solid supports, consisting of polypropylene blended with various agricultural materials (pp composite), were evaluated as supports for pure- and mixed-culture continuous lactic acid fermentations in biofilm reactors. Streptomyces viridosporus T7A (ATCC 39115) was used to form a biofilm, and Lactobacillus casei subsp. rhamnosus (ATCC 11443) was used for lactic acid production. For mixed-culture fermentations, a 15-day continuous fermentation of S. viridosporus was performed initially to establish the biofilm. The culture medium was then inoculated with L. casei subsp. rhamnosus. For pure-culture fermentation, L. casei subsp. rhamnosus was inoculated directly into the reactors containing sterile pp composite chips. The biofilm reactors containing various pp composite chips were compared with a biofilm reactor containing pure polypropylene chips and with a reactor containing a suspension culture. Continuous fermentation was started, and each flow rate (0.06 to 1.92 ml/min) was held constant for 24 h; steady state was achieved after 10 h. Lactic acid production was determined throughout the 24-h period by high-performance liquid chromatography. Production rates that were two to five times faster than those of the suspension culture (control) were observed for the pure- and mixed-culture bioreactors. Both lactic acid production rates and lactic acid concentrations in the culture medium were consistently higher in mixed-culture than in pure-culture fermentations. Biofilm formation on the chips was detected at harvest by chip clumping and Gram staining.

Demirci, Ali; Pometto, Anthony L.; Johnson, Kenneth E.

1993-01-01

49

192. View of the Richland Balsam Mountain Overlook. This is ...  

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

192. View of the Richland Balsam Mountain Overlook. This is the highest elevation, 6,047, on the Blue Ridge Parkway. Looking west-northwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

50

Reactivity margins in heavy water moderated production reactors  

SciTech Connect

The design of the reactor core and components of the heavy water moderated reactors at the Savannah River Plant (SFP) can be varied to produce a number of isotopes. For the past decade, the predominant reactor core design has been the enriched-depleted lattice. In this lattice, fuel assemblies of highly enriched uranium and target assemblies of depleted uranium, which produce plutonium, occupy alternate lattice positions. This heterogeneous lattice arrangement and a nonuniform control rod distribution result in a reactor core that requires sophisticated calculational methods for accurate reactivity margin and power distribution predictions. For maximum accuracy, techniques must exist to provide a base of observed data for the calculations. Frequent enriched-depleted lattice design changes are required as product demands vary. These changes provided incentive for the development of techniques to combine the results of calculations and observed reactivity data to accurately and conveniently monitor reactivity margins during operation.

Benton, F.D.

1981-11-01

51

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

52

Thermal reactor. [liquid silicon production from silane gas  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

53

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

54

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

NASA Astrophysics Data System (ADS)

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

Cormier, Jean Marie; Rusu, Iulian

2001-09-01

55

Nuclear Reactor: On Schedule and Under Cost.  

National Technical Information Service (NTIS)

The National Society of Professional Engineers has named the Fast Flux Test Facility (FFTF), an experimental nuclear reactor cooled by molten sodium, one of the nation's ten top engineering achievements of 1982. The reactor is located at Richland, Washing...

R. D. Larson

1983-01-01

56

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

57

A microBio reactor for hydrogen production.  

SciTech Connect

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

Volponi, Joanne V.; Walker, Andrew William

2003-12-01

58

Corrosion-product release in light water reactors  

Microsoft Academic Search

This is the final report of a research program aimed at measuring and studying the release of corrosion products from typical PWR and BWR materials to reactor coolant. The program has provided measurements of release from stainless steel, steam generator alloys and hard-facing material (Stellite) to PWR coolant under several chemistry conditions. Kinetic expressions for cumulative release as a function

D. Lister; R. D. Davidson

1989-01-01

59

Hydrogen peroxide production in trickle-bed electrochemical reactors  

Microsoft Academic Search

A trickle bed electrochemical reactor has been developed for the production of dilute alkaline peroxide solutions by reduction of oxygen. Oxygen gas and sodium hydroxide flow concurrently downward through a cell which consists of a thin packed cathode bed of graphite particles separated from the anode plate by a porous diphragm. Current flows perpendicular to the flow of electrolyte. The

C. Oloman; A. P. Watkinson

1979-01-01

60

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

61

A 5 MW TRIGA reactor design for radioisotope production  

Microsoft Academic Search

The production and preparation of commercial-scale quantities of radioisotopes has become an important activity as their medical and industrial applications continue to expand. There are currently various large multipurpose research reactors capable of producing ample quantities of radioisotopes. These facilities, however, have many competing demands placed upon them by a wide variety of researchers and scientific programs which severely limit

Anthony R. Veca; William L. Whittemore

1994-01-01

62

A proposed standard on medical isotope production in fission reactors  

SciTech Connect

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

Schenter, R. E. [Smart Bullets Inc., 2521 SW Luradel Street, Portland, OR 97219 (United States); Brown, G. J. [Ozarks Medical Center, Cancer Treatment Center, Shaw Medical Building, 1111 Kentucky Avenue, West Plains, MO 65775 (United States); Holden, C. S. [Thorenco LLC, 369 Pine Street, San Francisco, CA 94104 (United States)

2006-07-01

63

Mass production of magnetic nickel nanoparticle in thermal plasma reactor  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

64

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

65

Hydrogen Production via a Commercially Ready Inorganic membrane Reactor  

SciTech Connect

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

Paul K.T. Liu

2005-08-23

66

An evaluation of reactor cooling and coupled hydrogen production processes using the modular helium reactor  

Microsoft Academic Search

The high-temperature characteristics of the modular helium reactor (MHR) make it a strong candidate for producing hydrogen using either thermochemical or high-temperature electrolysis (HTE) processes. Using heat from the MHR to drive a sulfur-iodine (SI) thermochemical hydrogen production process has been the subject of a U.S. Department of Energy sponsored Nuclear Engineering Research Initiative (NERI) project led by General Atomics,

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

2006-01-01

67

Hydrogen production in a reversible flow filtration combustion reactor  

NASA Astrophysics Data System (ADS)

The noncatalytic process of syngas production by means of partial oxidation of methane by air oxygen in a reversible flow filtration combustion reactor has been investigated experimentally. We have investigated the influence of the equivalent ratio and the specific mass flow of the fuel mixture on the composition of conversion products and the maximum temperature in the reaction zone. The optimal conditions for the process providing the most effective conversion of methane to syngas have been established. The concentration of hydrogen is maximal for the equivalent ratio ? = 2.8 and the specific flow rate g = 1.8 kg / (m2?s).

Dmitrenko, Yu. M.; Klevan, P. A.

2011-11-01

68

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

69

75 FR 24958 - Decision To Evaluate a Petition To Designate a Class of Employees From the Hanford Site, Richland...  

Federal Register 2010, 2011, 2012, 2013

...Class of Employees From the Hanford Site, Richland, WA, To Be...class of employees from the Hanford site, Richland, Washington...is as follows: Facility: Hanford site. Location: Richland...of Employment: January 1, 1987 through December 31,...

2010-05-06

70

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

Code of Federal Regulations, 2010 CFR

...false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable...1305 Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

2010-07-01

71

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

Code of Federal Regulations, 2010 CFR

...false Richland, Washington, west coast outboard championship hydro races. 100.1305 Section 100.1305 Navigation and Navigable...1305 Richland, Washington, west coast outboard championship hydro races. (a) Regulated area. By this...

2009-07-01

72

Fission Product Release Behaviour after Reactor Shutdown: Experience at Tarapur Atomic Power Station.  

National Technical Information Service (NTIS)

A study on the fission product release behaviour after reactor shutdown has been carried out at Tarapur Atomic Power Station. The activity concentrations of iodines, caesium and technetium in reactor water have been measured. The release rates and release...

S. V. Narasimhan G. Venkateswaran K. S. Venkateswarlu

1977-01-01

73

Solar chemical reactor technology for industrial production of lime  

Microsoft Academic Search

We developed the solar chemical reactor technology to effect the endothermic calcination reaction CaCO3(s)?CaO(s)+CO2(g) at 12001400K. The indirect heating 10kWth multi-tube rotary kiln prototype processed 15mm limestone particles, producing high purity lime that is not contaminated with combustion by-products. The quality of the solar produced quicklime meets highest industrial standards in terms of reactivity (low, medium, and high) and degree

Anton Meier; Enrico Bonaldi; Gian Mario Cella; Wojciech Lipinski; Daniel Wuillemin

2006-01-01

74

Westinghouse independent safety review of Savannah River production reactors  

SciTech Connect

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

Leggett, W.D.; McShane, W.J. (Westinghouse Hanford Co., Richland, WA (USA)); Liparulo, N.J.; McAdoo, J.D.; Strawbridge, L.E. (Westinghouse Electric Corp., Pittsburgh, PA (USA). Nuclear and Advanced Technology Div.); Toto, G. (Westinghouse Electric Corp., Pittsburgh, PA (USA). Nuclear Services Div.); Fauske, H.K. (Fauske and Associates, Inc., Burr Ridge, IL (USA)); Call, D.W. (Westinghouse Savannah R

1989-04-01

75

Fracture mechanics and full scale pipe break testing for DOE's New Production Reactor-Heavy Water Reactor.  

National Technical Information Service (NTIS)

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 Reactor-Heavy Water Reactor (NPR-HWR), with its relatively moderate temperature and press...

A. B. Poole J. A. Clinard R. L. Battiste W. R. Hendrich

1992-01-01

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 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

77

Development of Enzymatic Membrane Reactor (EMR) for Cyclodextrins Production  

NASA Astrophysics Data System (ADS)

This study investigated on the fouling mechanisms in ultrafiltration membrane during separation of cyclodextrins from starch and CGTase. The Resistance-In-Series Model was used to identify the responsible hydraulic resistances. The result showed that the weak adsorption fouling resistance (ra1) was the main factor that contributed the rate and extent of flux decline. Moreover the significant organic fouling that is contributed by starch, CDs, CGTase and intermediate by-products in organic colloids and/or macromolecular revealed that the fouling potential was ra1> rg > rcp > ra2. The overall results indicate that the fouling mechanism consists of pore mouth adsorption and subsequently narrowing of the pores as those components (starch and CGTase) are small enough not to be excluded by steric considerations. In the latter stage unreacted starch would be accumulated to form gel/cake layer. The measured flux recovery of enzymatic membrane reactor for CDs production was about 95%.

Mimi Sakinah, A. M.; Ismail, A. F.; Illias, Rosli Md; Hassan, Osman

78

Reactor physics calculations for {sup 99}Mo production at the annular core research reactor  

SciTech Connect

The Isotope Production and Distribution Program at the U.S. Department of Energy has designated Sandia National Laboratories (SNL) as the most appropriate facility for the production of {sup 99}Mo, a radioisotope whose daughter, {sup 99m}Tc, is used in more than 36,000 medical procedures per day in the United States and is considered to be a vital medical diagnostic and treatment tool. The isotope would be produced at SNL using the annular core research reactor (ACRR) facility and collocated hot cell facility. The {sup 99}Mo would be produced using the fission process by irradiating {open_quotes}targets{close_quotes} coated with {sup 235}U in the form of highly enriched U{sub 3}O{sub 8}. After {approximately}7 days of continuous irradiation in the ACRR, a target would be re- moved from the reactor core for processing. The isotope would be extracted by chemically precipitating the molybdenum using the {open_quotes}Cintichem{close_quotes} process and would be shipped to the various pharmaceutical companies by commercial or chartered airline.

Parma, E.J. [Sandia National Labs., Albuquerque, NM (United States)

1995-12-31

79

Annual Energy Consumption Analysis Report for Richland Middle School  

SciTech Connect

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

Liu, Bing

2003-12-18

80

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

Microsoft Academic Search

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

Wei Han; Yong-Feng Li; Hong Chen; Jie-Xuan Deng; Chuan-Ping Yang

2010-01-01

81

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

82

Treatment of wastewater from red and tropical fruit wine production by zeolite anaerobic fluidized bed reactor  

Microsoft Academic Search

A study of the anaerobic treatment of wastewaters derived from red (RWWW) and tropical fruit wine (TFWWW) production was carried out in four laboratory-scale fluidized bed reactors with natural zeolite as bacterial support. These reactors operated at mesophilic temperature (35C). Reactors R1 and R2 contained Chilean natural zeolite, while reactors R3 and R4 used Cuban natural zeolite as microorganism support.

S. Montalvo; L. Guerrero; R. Borja; I. Corts; E. Snchez; M. F. Colmenarejo

2008-01-01

83

Reactor production of sup 252 Cf and transcurium isotopes  

SciTech Connect

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

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

1990-01-01

84

Reactor design for the 'UT-3' thermochemical hydrogen production process  

NASA Astrophysics Data System (ADS)

Results are presented from a theoretical and experimental study of one of the reactions constituting the UT-3 thermochemical decomposition cycle for hydrogen production. The reaction is expressed as: Fe3O4 + 8HBr yields 3FeBr2 + 4H2O + Br2. Magnetite powders mixed with silica-sol were fabricated into spheres, calcined at 900 C in a nitrogen stream and reacted with the HBr-H2O mixture. Based on the shrinking-core model, kinetic expressions were devised for both the higher (255-300 C) and lower (210-225 C) temperature ranges. The experimental kinetic data was then used to simulate the performance of a reactor employing a honeycomb-shaped solid reactant.

Kameyama, H.; Yoshida, K.

85

Synthesis gas production by biomass pyrolysis: Effect of reactor temperature on product distribution  

Microsoft Academic Search

This paper describes mass, C, H, and O balances for wood chips pyrolysis experiments performed in a tubular reactor under conditions of rich H2 gas production (7001000C) and for determined solid heating rates (2040Cs?1). Permanent gases (H2, CO, CH4, CO2, C2H4, C2H6), water, aromatic tar (10 compounds from benzene to phenanthrene and phenols), and char were considered in the balance

A. Dufour; P. Girods; E. Masson; Y. Rogaume; A. Zoulalian

2009-01-01

86

Uncertainties in the Anti-neutrino Production at Nuclear Reactors  

SciTech Connect

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

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

2008-08-06

87

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

88

Preliminary design of a low-temperature heavy water production reactor: nonelectric option  

SciTech Connect

This report describes a conceptual design for a low temperature heavy water reactor with no electricity generation (LTHWR-NE) to be built as a new production reactor at the Savannah River Plant (SRP). The reactor design is based on the proven SRP reactor design with enhancements and state-of-the-art equipment. Aluminum cladding temperatures would be the same as with current operations. The reactor will be built on a time schedule to allow startup testing in September 1991 and first operation in March 1992. A modified reactor design using the same aluminum cladding temperatures as C-Reactor but permitting natural circulation in both the primary and secondary coolant loops is presented in the Appendix. This concept would use the same primary loop flow, temperature range, and secondary coolant parameters as the design in Section I of this report. The differences between the two reactor designs are also discussed in the Appendix.

Buckner, M.R.; Graves, W.E.; McAllister, J.E.; Yau, W.W.F.

1982-09-01

89

Options for monitoring the US Russian bilateral cutoff agreement on shutdown of plutonium production reactors  

SciTech Connect

Six options are presented for monitoring operating Russian reactors and reprocessing plants under the bilateral cutoff agreement. In order of increasing intrusiveness they are: (A) monitoring of product (oxide or metal) storage only, supplemented with transparency measures at the reactors, (B) monitoring of product storage and reactor operating parameters, to assess reactor plutonium production, (C) monitoring of product storage, reactor operating parameters, and the input accountability tank of the reprocessing plant, (D) monitoring of product storage, the input accountability tank of the reprocessing plant, and application of surveillance to spent fuel, (E) IAEA/NPT-based material accountancy verification without major facility upgrades, and (F) IAEA/NPT-based safeguards, attempting to fulfill IAEA standards for material accountancy accuracy. Each of these options is considered in terms of cost, inspection effort, and effectiveness; however, the paper emphasizes the many uncertainties attendant on such assessments based on our current state of knowledge of these facilities.

Sanborn, J.; Fishbone, L.G.; Lu, Minh-Shih [Brookhaven National Lab., Upton, NY (United States); Stanbro, W. [Los Alamos National Lab., NM (United States); Libby, R. [Pacific Northwest Lab., Richland, WA (United States)

1994-07-01

90

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

91

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

92

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

Microsoft Academic Search

The Immobilized Cell Reactor-Separator (ICRS) consists of two column reactors: a cocurrent gas-liquid enricher followed by a countercurrent stripper. The columns are four-phase tubular reactors consisting of 1) an inert gas phase, 2) the liquid fermentation broth, 3) the solid column internal packing, and 4) the immobilized biological catalyst or cells. The application of the ICRS to the ethanol-from-whey-lactose fermentation

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

1985-01-01

93

An analysis of gamma-ray energy deposition in a heterogeneous liquid-metal fast breeder reactor  

Microsoft Academic Search

Gamma-dose analysis was performed on an absolute-value basis at the zero-power plutonium reactor (ZPPR)-13B\\/4 critical assembly, which was one of the benchmark radially heterogeneous 650-MW (electric) liquid-metal reactor cores, to validate the current data and methods applicable to power reactor design calculations. Discussions of particular aspects inherent to the critical measurements, such as heterogeneity in the ZPPR plate cells and

M. Kawashima; T. Yoshida; T. Yokoyama; T. Yamamoto

1989-01-01

94

Industrial production of fructooligosaccharides by immobilized cells of Aureobasidium pullulans in a packed bed reactor  

Microsoft Academic Search

Continuous production of fructooligosaccharides (FOS) by Aureobasidium pullulans immobilized on calcium alginate beads with a packed bed was investigated at a plant scale reactor. Optimum conditions were\\u000a with 770g sucrose\\/l, being fed at 200l\\/h at 50C which gave a productivity of 180g FOS\\/lh. Initial activity was maintained\\u000a for more than 100days. The reactor was successfully scaled up to a production

K. H. Jung; S. H. Bang; T. K. Oh; H. J. Park

2011-01-01

95

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.

96

Biological hydrogen production by Clostridium acetobutylicum in an unsaturated flow reactor  

Microsoft Academic Search

A mesophilic unsaturated flow (trickle bed) reactor was designed and tested for H2 production via fermentation of glucose. The reactor consisted of a column packed with glass beads and inoculated with a pure culture (Clostridium acetobutylicum ATCC 824). A defined medium containing glucose was fed at a flow rate of 1.6mL\\/min (0.096L\\/h) into the capped reactor, producing a hydraulic retention

Husen Zhang; Mary Ann Bruns; Bruce E. Logan

2006-01-01

97

Pipe break testing of primary loop piping similar to Department of Energy's New Production Reactor-Heavy Water Reactor.  

National Technical Information Service (NTIS)

Oak Ridge National Laboratory is completing a major task for the Department of Energy 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 suffe...

A. B. Poole R. L. Battiste J. A. Clinard W. R. Hendrich

1992-01-01

98

Sensitivity Studies of Advanced Reactors Coupled to High Temperature Electrolysis (HTE) Hydrogen Production Processes  

SciTech Connect

High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 C to 950 C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the steam or air sweep loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycle producing the highest efficiencies varied depending on the temperature range considered.

Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

2007-04-01

99

STAR - H2 : the secure transportable autonomous reactor for hydrogen production and desalinization.  

SciTech Connect

The Secure Transportable Autonomous Reactor for Hydrogen production is a modular fast reactor intended for the mid 21st century energy market wherein electricity and hydrogen are employed as complementary energy carriers and nuclear energy contributes to sustainable energy supply based on full transuranic recycle in a passively safe, environmentally friendly and proliferation-resistant manner suitable for widespread worldwide deployment.

Wade, D.C.; Doctor, R.; Peddicord, K.L.

2002-02-26

100

Conversion of the Russian plutonium production reactors: Transition to the second phase  

Microsoft Academic Search

The operation of the Russian plutonium production reactors continues to attract the interest of political leaders and the public. Though designed to manufacture weapon-grade plutonium for weapons, the three large graphite reactors, two located at Tomsk-7 and one at Krasnoyarsk-26, are also used to supply electric power and heat to local inhabitants. Efforts to replace the reac- tors with fossil

Alexander M. Dmitrieva

1998-01-01

101

ACRR (Annular Core Research Reactor) fission product release tests: ST1 and ST2  

Microsoft Academic Search

Two experiments (ST-1 and ST-2) have been performed in the Annular Core Research Reactor (ACER) at Sandia National Laboratories (SNLA) to obtain time-resolved data on the release of fission products from irradiated fuels under light water reactor (LWR) severe accident conditions. Both experiments were conducted in a highly reducing environment at maximum fuel temperatures of greater than 2400 K. These

M. D. Allen; H. W. Stockman; K. O. Reil; A. J. Grimley; W. J. Camp

1988-01-01

102

Argon-41 production and evolution at the Oregon State University TRIGA Reactor (OSTR)  

SciTech Connect

In this study, argon-41 concentrations were measured at various locations within the reactor facility to assess the accuracy of models used to predict argon-41 evolution from the reactor tank, and to determine the relationship between argon gas evolution from the tank and subsequent argon-41 concentrations throughout the reactor room. In particular, argon-41 was measured directly above the reactor tank with the reactor tank lids closed, at other accessible locations on the reactor top with the tank lids both closed and open, and at several locations on the first floor of the reactor room. These measured concentrations were then compared to values calculated using a modified argon-41 production and evolution model for TRIGA reactor tanks and ventilation values applicable to the OSTR facility. The modified model was based in part on earlier TRIGA models for argon-41 production and release, but added features which improved the agreement between predicted and measured values. The approximate dose equivalent rate due to the presence of argon-41 in reactor room air was calculated for several different locations inside the OSTR facility. These dose rates were determined using the argon-41 concentration measured at each specific location, and were subsequently converted to a predicted quarterly dose equivalent for each location based on the reactor's operating history. The predicted quarterly dose equivalent values were then compared to quarterly doses measured by film badges deployed as dose-integrating area radiation monitors at the locations of interest. The results indicate that the modified production and evolution model is able to predict argon-41 concentrations to within a factor of ten when compared to the measured data. Quarterly dose equivalents calculated from the measured argon-41 concentrations and the reactor's operating history seemed consistent with results obtained from the integrating area radiation monitors. Given the argon-41 concentrations measured, it may be safely concluded that argon-41 produced in the OSU TRIGA research reactor tank poses no significant health hazard to workers or to the public.

Anellis, L.G.; Johnson, A.G.; Higginbotham, J.F. [Oregon State University Radiation Center, OR (United States)

1988-07-01

103

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

104

Biological hydrogen production by Clostridium acetobutylicum in an unsaturated flow reactor.  

PubMed

A mesophilic unsaturated flow (trickle bed) reactor was designed and tested for H2 production via fermentation of glucose. The reactor consisted of a column packed with glass beads and inoculated with a pure culture (Clostridium acetobutylicum ATCC 824). A defined medium containing glucose was fed at a flow rate of 1.6 mL/min (0.096 L/h) into the capped reactor, producing a hydraulic retention time of 2.1 min. Gas-phase H2 concentrations were constant, averaging 74 +/- 3% for all conditions tested. H2 production rates increased from 89 to 220 mL/hL of reactor when influent glucose concentrations were varied from 1.0 to 10.5 g/L. Specific H2 production rate ranged from 680 to 1270 mL/g glucose per liter of reactor (total volume). The H2 yield was 15-27%, based on a theoretical limit by fermentation of 4 moles of H2 from 1 mole of glucose. The major fermentation by-products in the liquid effluent were acetate and butyrate. The reactor rapidly (within 60-72 h) became clogged with biomass, requiring manual cleaning of the system. In order to make long-term operation of the reactor feasible, biofilm accumulation in the reactor will need to be controlled through some process such as backwashing. These tests using an unsaturated flow reactor demonstrate the feasibility of the process to produce high H2 gas concentrations in a trickle-bed type of reactor. A likely application of this reactor technology could be H2 gas recovery from pre-treatment of high carbohydrate-containing wastewaters. PMID:16427113

Zhang, Husen; Bruns, Mary Ann; Logan, Bruce E

2006-02-01

105

Liquid phase methanol reactor staging process for the production of methanol  

DOEpatents

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

Bonnell, Leo W. (Macungie, PA); Perka, Alan T. (Macungie, PA); Roberts, George W. (Emmaus, PA)

1988-01-01

106

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

PubMed

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 3 days, and the UASB and AF reactors were operated at 1 day HRT, using mixed extreme thermophiles at 70 C. The highest hydrogen production yield of 212.06.6 mL-H?/g-sugars, corresponding to a hydrogen production rate of 821.425.5 mL-H?/dL was achieved with the UASB reactor. Lowering the HRT to 2.5 days caused cell mass washout in the CSTR, while the UASB and AF reactors gave fluctuating and reducing hydrogen production at a 0.5-day HRT. The original rate and yield were recovered when the HRT was increased back to 1 day. These results demonstrate that reactor configuration is an important factor for enhancing and stabilizing H? production. PMID:20554199

Kongjan, Prawit; Angelidaki, Irini

2010-10-01

107

Anaerobic digestion of corn stovers for methane production in a novel bionic reactor.  

PubMed

To improve the biogas production from corn stovers, a new bionic reactor was designed and constructed. The bionic reactor simulated the rumen digestion of ruminants. The liquid was separated from corn stovers and refluxed into corn stovers again, which simulated the undigested particles separated from completely digested materials and fed back again for further degradation in ruminant stomach. Results showed that the bionic reactor was effective for anaerobic digestion of corn stovers. The liquid amount and its reflux showed an obvious positive correlation with biogas production. The highest biogas production rate was 21.6ml/gVS-addedd, and the total cumulative biogas production was 256.5ml/gVS-added. The methane content in biogas ranged from 52.2% to 63.3%. The degradation of corn stovers were greatly enhanced through simulating the animal digestion mechanisms in this bionic reactor. PMID:24923659

Zhang, Meixia; Zhang, Guangming; Zhang, Panyue; Fan, Shiyang; Jin, Shuguang; Wu, Dan; Fang, Wei

2014-08-01

108

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

Microsoft Academic Search

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

W. E. Cawley; R. P. Omberg

1982-01-01

109

Reactor fuel and target arrangement for enhanced production of tritium. [LMFBR  

Microsoft Academic Search

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

Cawley

1982-01-01

110

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

Microsoft Academic Search

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

W. E. Cawley; R. P. Omberg

1982-01-01

111

Simulation of methane production in a laboratory-scale reactor containing hydrate-bearing porous medium  

SciTech Connect

Production of methane, induced by depressurization of hydrate sediment in a reactor, was investigated by numerical simulations using a computational fluid dynamics code TOUGH+/Hydrate. The methane production rates were computed at well-pressure drops of 4.2, 14.7, and 29.5 MPa and at a reactor temperature of 21 0C. The predicted behavior of methane production from the reactor is consistent with field-scale simulations and observations. The production rate increases with pressure drop at the well. Evolution patterns of gas and hydrate distributions are similar to those obtained in field-scale simulations. These preliminary results clearly indicate that numerical simulators can be applied to laboratory-scale reactors to anticipate scenarios observed in field experiments.

Gamwo, I.K.; Myshakin, E.M.; Zhang, Wu; Warzinski, R.P.

2008-01-01

112

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

113

A multiphase\\/extractive enzyme membrane reactor for production of diltiazem chiral intermediate  

Microsoft Academic Search

Enzyme membrane reactors can be used to enhance the productivity and practicality of certain biotransformations by improving substrate\\/enzyme contact, by providing a simple and reversible means of enzyme immobilization, and by effecting the removal of inhibitory reaction products. This paper describes the development and eventual scale-up of a multiphase\\/extractive membrane reactor designed to manage reaction problems encountered in a biphasic

Jorge L. Lopez; Stephen L. Matson

1997-01-01

114

Determination of argon-41 production at the Texas A and M Nuclear Science Center reactor  

Microsoft Academic Search

Accountability of the potential sources of Argon-41 was performed at the NSC Research Reactor with production levels and release rates determined under various conditions. The reactor pool was found to be the major source accounting for more than 95% of the total production or about 7.6 Ci\\/yr. The irradiation cell produces about .25 Ci\\/yr., with approximately 80% from steady state

E. F. Bates; J. D. Randall; R. D. Neff; Ken Walker

1976-01-01

115

Biohydrogen production from biomass and molasses wastewater by anaerobic fermentation in continuous stirred-tank reactor  

Microsoft Academic Search

Hydrogen is a clean energy carrier which has a great potential to be an alternative fuel. Abundant biomass from various industries could be a source for biohydrogen production where combination of waste treatment and energy production would be an advantage. A study of biohydrogen production using aerobic-pretreated sludge and molasses by anaerobic fermentation in continuous stirred-tank reactor (CSTR) was investigated.

Han Wei; Li Yong-feng; Deng Jie-xuan

2010-01-01

116

Current status and future plan for the production of radioisotopes using HANARO Research Reactor  

Microsoft Academic Search

The Korea Atomic Energy Research Institute (KAERI) completed the High-flux Advanced Neutron Application Reactor (HANARO) in 1995 and the radioisotope production facilities(RIPF) in 1997. Many devices and handling tools were developed and applied for the production of radioisotopes. Emphasis on RI production plan was placed on the development of new radiopharmaceuticals, the development of new radiation sources for industrial use

H. S. Han; W. K. Cho; U. J. Park; Y. D. Hong; K. B. Park

2003-01-01

117

Analysis of fission product revaporization in a BWR reactor cooling system during a station blackout accident  

SciTech Connect

A preliminary analysis of the re-evaporization of volatile fission product from a boiling water reactor (BWR) cooling system following a core meltdown accident in which the core debris penetrates the reactor vessel has been performed. The BWR analyzed has a Mark I containment and the accident sequence was a station blackout transient. This work was performed as part of the phenomenological uncertainty study of the Quantification and Uncertainty Analysis of Source Terms for Severe Accidents program at Brookhaven National Laboratory. Fission product re-evaporization was identified as one of the important issues in the Reactor Risk Reference Document.

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

1988-01-01

118

[Full-scale experiment on corn-ethanol production wastewater treatment with the thermophilic EGSB reactor].  

PubMed

Full-scale EGSB reactor was used in the treatment of corn ethanol production wastewater that was a typical kind of high strength wastewater in North China. As the COD loading rate was as high as 29 kg/(m3.d), the usual SS content was 6000 mg.L-1, COD removal efficiency remained up to 90%, In addition, the reactor started up successfully in only two months with the formation of granular as a symbol. Through this experiment, the conclusion was drawn that the EGSB reactor is greatly efficient in the treatment of corn ethanol production wastewater. PMID:11569102

Zhang, Z; Zhou, W; Lin, R

2001-07-01

119

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

120

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

PubMed

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

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

2013-11-01

121

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

122

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

123

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

PubMed

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

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

2011-01-01

124

Reactor production of sup 252 Cf and transcurium isotopes  

Microsoft Academic Search

Berkelium, californium, einsteinium, and fermium are currently produced in the High Flux Isotope Reactor (HFIR) and recovered in the Radiochemical Engineering Development Center (REDC) at the Oak Ridge National Laboratory (ORNL). All the isotopes are used for research. In addition, ²⁵²Cf, ²⁵³Es, and ²⁵⁵Fm have been considered or are used for industrial or medical applications. ORNL is the sole producer

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

1990-01-01

125

Practical reactor production of 41 Ar from argon clathrate  

Microsoft Academic Search

The radionuclide 41Ar has many ideal properties as a gas flow tracer. However, the modest cross-section of 40Ar for thermal neutron activation makes preparation of suitable activities of 41Ar technically difficult particularly for low flux reactors. Argon can however be trapped in a molecular complex called a clathrate that can then be irradiated. We prepared argon clathrate and explored its

John R. Mercer; M. John M. Duke; Stephen A. McQuarrie

2000-01-01

126

Production of penicillins and cephalosporins in an immobilized enzyme reactor  

Microsoft Academic Search

Four enzymes required for the biosynthesis of pencillins and cephalosporins by Streptomyces clavuligerus have been immobilized on an anion exchange resin. The capabilities of the system have been studied by circulation of reaction mixtures through the immobilized enzyme reactor. Within 30 min, all of the substrate d-(l-a-aminoadipyl)-l-cysteinyl-d-valine is consumed and converted to a mixture of penicillins and cephalosporins. After 60

Susan E. Jensen; Donald W. S. Westlake; Saul Wolfe

1984-01-01

127

Fission product release and fuel behavior of irradiated light water reactor fuel under severe accident conditions  

SciTech Connect

The annular Core Research Reactor (ACRR) Source Term (ST) Experiment program was designed to obtain time-resolved data on the release of fission products from irradiated fuels under well-controlled light water reactor severe accident conditions. The ST-1 Experiment was the first of two experiments designed to investigate fission product release. ST-1 was conducted in a highly reducing environment at a system pressure of approximately 0.19 MPa, and at maximum fuel temperatures of about 2490 K. The data will be used for the development and validation of mechanistic fission product release computer codes such as VICTORIA.

Allen, M.D.; Stockman, H.W.; Reil, K.O. (Sandia National Labs., Albuquerque, NM (United States)); Fisk, J.W. (Tills (Jack) and Associates, Inc., Albuquerque, NM (United States))

1991-11-01

128

Impact of varying lignocellulosic sugars on continuous solvent production in an immobilized column reactor.  

PubMed

The effect of varying glucose, mannose and xylose concentrations on continuous solvent production at various dilution rates was studied by multiple linear regression (MLR) modeling using an immobilized column reactor. The factors affecting the solvent production were dilution rate and concentrations of glucose and mannose. MLR-models also showed a preference of glucose as well as its inhibitory effect on xylose consumption. The fermentation process was studied at bigger scale with a volume factor of 17 with an added recirculation loop in the system. The up-scaled reactor produced 12.5 g/l of acetone-butanol-ethanol (ABE) solvents at a dilution rate of 0.23 h(-1), as compared to 13.4 g/l with a smaller column reactor. The xylose utilization was significantly higher in the modified reactor (73%) as compared to the small scale (43%). PMID:24001559

Viikil, Matti; Wallenius, Janne; Ojamo, Heikki; Granstrm, Tom; Survase, Shrikant A

2013-11-01

129

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

Microsoft Academic Search

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

F. Capone; J. P. Hiernaut; M. Martellenghi; C. Ronchi

1996-01-01

130

Biomass pyrolysis in a circulating fluid bed reactor for the production of fuels and chemicals  

Microsoft Academic Search

An approach for biomass flash pyrolysis in a circulating fluid bed (CFB) reactor with continuous solids regeneration is described in this study. The unit is capable of performing conventional and catalytic biomass pyrolysis with the proper solid selection. The production of improved quality liquid products in a direct step through catalytic pyrolysis is investigated in this work. Both conventional and

A. A Lappas; M. C Samolada; D. K Iatridis; S. S Voutetakis; I. A Vasalos

2002-01-01

131

Production of {sup 99}Mo at the annular core research reactor-recent calculative results  

SciTech Connect

Significant progress has been made over the past year in understanding the chemistry and processing challenges associated with {sup 99}Mo production using Cintichem-type targets. Targets fabricated at Los Alamos National Laboratory have been successfully irradiated in fuel element locations at the Annular Core Research Reactor (ACRR) and processed at the Sandia Hot Cell Facility. The next goal for the project is to remove the central cavity experiment tube from the reactor core, allowing for the irradiation of up to 37 targets. After the in-core work is complete, the reactor will be capable of producing significant quantities of {sup 99}Mo.

Parma, E.J. [Sandia National Labs., Albuquerque, NM (United States)

1997-12-01

132

Mo-99 production at the Annular Core Research Reactor - recent calculative results  

SciTech Connect

Significant progress has been made over the past year in understanding the chemistry and processing challenges associated with {sup 99}Mo production using Cintichem type targets. Targets fabricated at Los Alamos National Laboratory have been successfully irradiated in fuel element locations at the Annular Core Research Reactor (ACRR) and processed at the Sandia Hot Cell Facility. The next goal for the project is to remove the central cavity experiment tube from the reactor core, allowing for the irradiation of up to 37 targets. After the in-core work is complete, the reactor will be capable of producing significant quantities of {sup 99}Mo.

Parma, E.J.

1997-11-01

133

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

Microsoft Academic Search

High flux of electron neutrinos(nue) 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 51Cr and 55Fe give rise to monoenergetic nue's at Q-values of 753 keV and 231 keV and fluxes of 8.310-4 and 3.010-4nue\\/fission,

B. Xin; H. T. Wong; C. Y. Chang; C. P. Chen; H. B. Li; J. Li; F. S. Lee; S. T. Lin; V. Singh; F. Vannucci; S. C. Wu; Q. Yue; Z. Y. Zhou

2005-01-01

134

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

NASA Astrophysics Data System (ADS)

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

Dolan, David J.

135

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

136

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

Code of Federal Regulations, 2013 CFR

...100.1305 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.1305 Richland, Washington, west coast outboard championship hydro...

2013-07-01

137

78 FR 37222 - Columbia Organic Chemical Company Site, Columbia, Richland County, South Carolina; Notice of...  

Federal Register 2010, 2011, 2012, 2013

...Compensation and Liability Act (CERCLA), the United States Environmental Protection Agency has entered into a settlement with Stephen Reichlyn concerning the Columbia Organic Chemical Company Superfund Site located in Columbia, Richland County, South...

2013-06-20

138

Process and reactor design for biophotolytic hydrogen production.  

PubMed

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

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

2013-07-14

139

Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations  

SciTech Connect

The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa [Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yusung-gu, Taejon (Korea, Republic of)

2005-05-24

140

Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations  

NASA Astrophysics Data System (ADS)

The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa

2005-05-01

141

Radioisotope production experience at the Cintichem 5-MW research reactor  

SciTech Connect

The Cintichem radiochemical production facility was constructed in the late 1950s and became operational in October of 1961. The facility was originally designed and constructed by Union Carbide Corporation for research and development of nuclear technology with the ultimate objective of exploiting it commercially. Research projects were conducted in the fields of direct energy conversion for the production of electric power and chemical synthesis, neutron spectrometry, nuclear fuel cycle development, and radiochemical production. Radiochemical production for medical applications was the only development project that was successfully commercialized.

McGovern, J.J. (Cintichem, Inc., Tuxedo, NY (United States))

1993-01-01

142

Enhanced tritium production for fusion reactors via 3 He(n, p) 3 H in the heavy water moderator of a CANDU reactor  

Microsoft Academic Search

There is an increasing requirement for tritium to supply the fuel needs of current experimental fusion devices and in the initial startup of future power generating reactors. Tritium is produced in heavy water reactors through deuterium activation, but the total production capacity of Canadian operated CANDUs will fall short of future demands, during the period before and for some time

Gerald F. Thomas; Sandra J. Brereton

1985-01-01

143

Full scale fluidized bed anaerobic reactor for domestic wastewater treatment: performance, sludge production and biofilm.  

PubMed

This paper describes the performance, sludge production and biofilm characteristics of a full scale fluidized bed anaerobic reactor (32 m3) for domestic wastewater treatment. The reactor was operated with 10.5 m x h(-1) upflow velocity, 3.2 h hydraulic retention time, and recirculation ratio of 0.85 and it presented removal efficiencies of 71+/-8% of COD and 77+/-14% of TSS. During the apparent steady-state period, specific sludge production and sludge age in the reactor were (0.116+/-0.033) kgVSS. kgCOD(-1) and (12+/-5)d, respectively. Biofilm formed in the reactor presented two different patterns: one of them at the beginning of the colonization and the other of mature biofilm. These different colonization patterns are due to bed stratification in the reactor, caused by the difference in local-energy dissipation rates along the reactor's height, and density, shape, etc. of the bioparticles. The biofilm population is formed mainly of syntrophic consortia among sulfate reducing bacteria, methanogenic archaea such as Methanobacterium and Methanosaeta-like cells. PMID:15303757

Mendona, N M; Niciura, C L; Gianotti, E P; Campos, J R

2004-01-01

144

Performance of coimmobilized yeast and amyloglucosidase in a fluidized bed reactor for fuel ethanol production.  

PubMed

The performance of coimmobilized Saccharomyces cerevisiae and amyloglucosidase (AG) was evaluated in a fluidized-bed reactor. Soluble starch and yeast extracts were used as feed stocks. Conversion of soluble starch streams to ethanol has potential practical applications in corn dry and wet milling and in developmental lignocellulosic processes. The biocatalyst performed well, and demonstrated no significant loss of activity or physical integrity during 10 wk of continuous operation. The reactor was easily operated and required no pH control. No operational problems were encountered from bacterial contaminants even though the reactor was operated under nonsterile conditions over the entire course of experiments. Productivities ranged between 25 and 44 g ethanol/L/h/. The experiments demonstrated that ethanol inhibition and bed loading had significant effects on reactor performance. PMID:9170248

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

1997-01-01

145

THE IEA-R1 RESEARCH REACTOR: 50 YEARS OF OPERATING EXPERIENCE AND UTILIZATION FOR RESEARCH, TEACHING AND RADIOISOTOPES PRODUCTION  

Microsoft Academic Search

This paper describes almost 50 years of operating e xperience and utilization of the IEA-R1 research reactor for research, teaching and radioisotopes production. The current and future program of upgrading the reactor is also described. IEA-R1 research reactor at the Instituto de Pesquisas Energticas e Nucleares (IPEN), Sao Paulo, Brazil is the largest power research reactor in Brazil, with a

Rajendra N. Saxena

146

Improvement in the bioreactor specific productivity by coupling continuous reactor with repeated fed-batch reactor for acetone-butanol-ethanol production.  

PubMed

In comparison to the different fermentation modes for the production of acetone, butanol and ethanol (ABE) researched to date, the continuous fermentation is the most economically favored. Continuous fermentation with two or more reactor cascade is reported to be the most efficient as it results in a more stable solvent production process. In this work, it is shown that a continuous (first-stage) reactor coupled to a repeated fed-batch (second stage) is superior to batch and fed-batch fermentations, including two-stage continuous fermentation. This is due to the efficient catalyst use, reported through the specific product rate and rapid glucose consumption rate. High solvents are produced at 19.4 g(ABE) l?, with volumetric productivities of 0.92 g(butanol) l? h? and 1.47 g(ABE) l ? h?. The bioreactor specific productivities of 0.62 and 0.39 g g?(cdw) h? obtained show a high catalyst activity. This new process mode has not been reported before in the development of ABE fermentation and it shows great potential and superiority to the existing fermentation methods. PMID:22542935

Setlhaku, Mpho; Brunberg, Sina; Villa, Eva Del Amor; Wichmann, Rolf

2012-10-15

147

Electrochemically assisted methane production in a biofilm reactor  

Microsoft Academic Search

Microbial electrolysis is a new technology for the production of value-added products, such as gaseous biofuels, from waste organic substrates. This study describes the performance of a methane-producing microbial electrolysis cell (MEC) operated at ambient temperature with a Geobacter sulfurreducens microbial bioanode and a methanogenic microbial biocathode. The cell was initially operated at a controlled cathode potential of ?850mV (vs.

Marianna Villano; Gianluca Monaco; Federico Aulenta; Mauro Majone

2011-01-01

148

Reactor physics calculations for ⁹⁹Mo production at the annular core research reactor  

Microsoft Academic Search

The Isotope Production and Distribution Program at the U.S. Department of Energy has designated Sandia National Laboratories (SNL) as the most appropriate facility for the production of ⁹⁹Mo, a radioisotope whose daughter, {sup 99m}Tc, is used in more than 36,000 medical procedures per day in the United States and is considered to be a vital medical diagnostic and treatment tool.

Parma

1995-01-01

149

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

150

Hydrogen Production by High Temperature Electrolysis with Nuclear Reactor  

Microsoft Academic Search

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

Takashi Ogawa; Seiji Fujiwara; Shigeo Kasai; Kazuya Yamada

2007-01-01

151

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

Microsoft Academic Search

The Pacific Northwest Laboratory (PNL) conducted this air quality impact analysis for the US Department of Energy (DOE). The purpose of this work was to provide Argonne National Laboratory (ANL) with the required estimates of ground-level concentrations of five criteria air pollutants at the Hanford Site boundary from each of the stationary sources associated with the new production reactor (NPR)

Hadley

1991-01-01

152

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

153

Co-Product Extraction Studies on n-Reactor Pt-57 Target Materials.  

National Technical Information Service (NTIS)

Single pellets (of approximately 70 g each) of irradiated lithium aluminate target from N-Reactor test PT-57 were used in a series of experiments to determine the extent to which the product tritium can be recovered by (a) vacuum outgassing of the target ...

W. H. Yunker W. O. Greenhalgh J. R. Lundquist T. S. Soine K. M. Harmon

1966-01-01

154

In-reactor simulation study of zinc injection to reduce radioactive corrosion product transport in PWRs  

Microsoft Academic Search

Corrosion products containing transition metal elements that deposit in core become radioactive and then are released and redeposited on components such as steam generators, pumps, and coolant piping are a significant source of radiation exposure to workers in commercial power reactors. A number of strategies have been developed to reduce the buildup of radiation fields, including careful control of primary

K. Hsueh; G. Kohse; O. K. Harling

1995-01-01

155

Data Sheets of Fission Product Release Experiments for Light Water Reactor Fuel, (2).  

National Technical Information Service (NTIS)

This is the second data sheets of fission products (FP) release experiments for light water reactor fuel. Results of five FP release experiments from the third to the seventh are presented: results of pre-examinations of UO sub 2 pellets, photographs of p...

N. Ishiwatari H. Nagai T. Takeda K. Yamamoto C. Nakazaki

1979-01-01

156

Data Sheets of Fission Product Release Experiments for Light Water Reactor Fuel, (3).  

National Technical Information Service (NTIS)

This report is the last data sheets in series of fission product (FP) release experiments for light water reactor (LWR) fuel. Experimental results in the eighth run (in part), and those in the ninth run in OWL-1 of JMTR, are recorded; photographs of fuel ...

N. Ishiwatari H. Nagai K. Yamamoto T. Hirota H. Itami

1981-01-01

157

Data Sheets of Fission Product Release Experiments for Light Water Reactor Fuel, (1).  

National Technical Information Service (NTIS)

A series of fission product (FP) release experiments is proceeding with Oarai Water Loop 1 (OWL-1) installed to the JMTR. The purpose is to clarify behavior and mechanism of FP release from a defective fuel rod in normal operation light water reactor (LWR...

K. Yamamoto C. Nakazaki H. Itami N. Ishiwatari Y. Togo

1979-01-01

158

Characteristics and biogas production potential of municipal solid wastes pretreated with a rotary drum reactor  

Microsoft Academic Search

This study was conducted to determine the characteristics and biogas production potential of organic materials separated from municipal solid wastes using a rotary drum reactor (RDR) process. Four different types of wastes were first pretreated with a commercial RDR system at different retention times (1, 2 and 3 d) and the organic fractions were tested with batch anaerobic digesters with

Baoning Zhu; Petros Gikas; Ruihong Zhang; James Lord; Bryan Jenkins; Xiujin Li

2009-01-01

159

WIMS-E benchmark of the light water new production reactor diamond cell.  

National Technical Information Service (NTIS)

The primary design tools used in the development of the conceptual core designs for the WNP-1 New Production Reactor (WNP-l/NPR) consisted of the WIMS-E (Askew and Roth 1982) and EMERALD computer codes. The WIMS-E code was used to generate the cross secti...

B. D. Reid K. A. Pauley R. A. Jensen T. L. Miles

1992-01-01

160

A NOVEL CONTINUOUS-FLOW REACTOR USING REACTIVE DISTILLATION FOR BIODIESEL PRODUCTION  

Microsoft Academic Search

The production of biodiesel through batch and existing continuous-flow processes requires the use of a much higher excess alcohol, typically 100%, than the stoichiometric molar requirement in order to drive the transesterification reaction to completion. This excess alcohol must be recovered in a separate process, which involves additional capital and operating costs. In this study, a novel reactor system using

B. B. He; A. P. Singh; J. C. Thompson

161

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

Microsoft Academic Search

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

P. M. Satya Sai; Jaleel Ahmed; K. Krishnaiah

1997-01-01

162

Optimizing Program for the Calculation of Isotope Production in a Nuclear Reactor.  

National Technical Information Service (NTIS)

The numerical solution of the optimization problem of isotope production in a nuclear reactor is considered. It is assumed that the exposed target consists of a mixture of isotopes with the given initial concentrations. The exposure time is fixed. The the...

A. I. Volovik A. S. Gerasimov S. A. Nemirovskaya

1979-01-01

163

Corrosion and fission products in primary systems of liquid metal cooled reactors in the USA  

SciTech Connect

This paper presents a summary of the work in the USA to support the measurement and control of radionuclides in primary systems of liquid metal cooled reactors. The efforts to characterize and control the ingress of radioactive corrosion and fission products, fuel particles, and radioactivity in gas systems have been quite successful in the USA.

Brehm, W.F.; Colburn, R.P.; Maffei, H.P.; Stinson, W.P.; Bunch, W.L.; Bechtold, R.A.; Olson, W.H.

1987-01-01

164

Removal of anaerobic soluble microbial products in a biological activated carbon reactor.  

PubMed

The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable. Focusing on the biodegradation of anaerobic SMP, the biological activated carbon (BAC) was introduced into the anaerobic system. The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors. The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2, i.e., BAC) functioned as a polishing step to remove SMP produced in UASB1. The results showed that 90% of the SMP could be removed before granular activated carbon was saturated. After the saturation, the SMP removal decreased to 60% on the average. Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation. A strain of SMP-degrading bacteria, which was found highly similar to Klebsiella sp., was isolated, enriched and inoculated back to the BAC reactor. When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3 x day), the effluent from the BAC reactor could meet the discharge standard without further treatment. Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective, cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L. PMID:24520716

Dong, Xiaojing; Zhou, Weili; He, Shengbing

2013-09-01

165

Biological fermentative hydrogen and ethanol production using continuous stirred tank reactor  

Microsoft Academic Search

Hydrogen and ethanol are promising biofuels and have great potential to become alternatives to fossil fuels. The influence of organic loading rates (OLRs) on the production of fermentative hydrogen and ethanol were investigated in a continuous stirred tank reactor (CSTR) from fermentation using molasses as substrate. Four OLRs were examined, ranging from 8 to 32kg\\/m3d. The H2 and ethanol production

Wei Han; Hong Chen; Anying Jiao; Zhanqing Wang; Yongfeng Li; Nanqi Ren

166

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

SciTech Connect

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

Mo, S.C.

1993-12-31

167

Bio-hydrogen Production in an EGSB Reactor Under Mesophilic, Thermophilic and Hyperthermophilic Conditions  

Microsoft Academic Search

Mesophilic, thermophilic and hyperthermophilic bio-hydrogen production with an expanded granular sludge blanket (EGSB) fed with glucose and arabinose, without methane production, was demonstrated. Homoacetogenesis was observed on reactor when operated under mesophilic (37C) conditions but not under thermophilic (55C) and hyper-thermophilic conditions (70C). It was also found that under thermophilic and hyper-thermophilic conditions glucose is preferentially consumed than arabinose.

A. A. Abreu; A. S. Danko; M. M. Alves

168

USE OF THE MODULAR HELIUM REACTOR FOR HYDROGEN PRODUCTION  

Microsoft Academic Search

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

K. R. Schultz

2003-01-01

169

Control of an anaerobic reactor towards maximum biogas production  

Microsoft Academic Search

A new control strategy is introduced for operating anaerobic digestion processes efficiently at high load. The control system includes a cascade controller embedded into a rule-based supervisory system based on extremum-seeking control. The control system measures pH and biogas production rate and varies the organic load by manipulating the influent flow. Good control performances were achieved during the start-up and

J. Liu; G. Olsson; B. Mattiasson

170

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

SciTech Connect

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

Dale, M.C.

1983-01-01

171

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

172

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)? h? at a superficial velocity of 7.6 cm min?, 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)? h?. 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

173

Reactor physics calculations for {sup 99}Mo production at the Annular Core Research Reactor  

SciTech Connect

The isotope {sup 99}Mo would be produced at Sandia using ACRR and the collocated Hot Cell Facility. {sup 99}Mo would be produced by irradiating targets coated with {sup 235}U in the form of highly enriched U{sub 3}O{sub 8}; after 7 days, the target would be removed and the isotope extracted using the Cintichem process. The Monte Carlo neutronics computer code MCNP was used to determine the optimum configuration for production, using various fractions of the US demand. Although ACRR operates at a low power level, the US demand for {sup 99}Mo can be easily met using a reasonable number of targets.

Parma, E.J.

1995-07-01

174

Medical isotope production: A new research initiative for the Annular Core Research Reactor  

SciTech Connect

An investigation has been performed to evaluate the capabilities of the Annular Core Research Reactor and its supporting Hot Cell Facility for the production of {sup 99}Mo and its separation from the fission product stream. Various target irradiation locations for a variety of core configurations were investigated, including the central cavity, fuel and reflector locations, and special target configurations outside the active fuel region. Monte Carlo techniques, in particular MCNP using ENDF B-V cross sections, were employed for the evaluation. The results indicate that the reactor, as currently configured, and with its supporting Hot Cell Facility, would be capable in meeting the current US demand if called upon. Modest modifications, such as increasing the capacity of the external heat exchangers, would permit significantly higher continuous power operation and even greater {sup 99}Mo production ensuring adequate capacity for future years.

Coats, R.L.; Parma, E.J.

1993-12-31

175

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

176

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

177

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

178

Ethanol production in a multimembrane bioreactor: Cell and reactor modeling and continuous fermentation  

SciTech Connect

A novel bioreactor, in which hydrophilic and hydrophobic membranes segregate cells, nutrient, and solvent, has been previously described. The model system studied has been ethanol production by Saccharomyces cerevisiae with tributyl phosphate as the extractive solvent. A structured, nonsegregated model of model of Saccharomyces cerevisiae, similar in philosophy to the E. coli models extensively developed at Cornell, has been constructed. The model establishes a basis for a realistic model of multi-membrane bioreactor fermentations as well as lays the groundwork for an increasingly detailed description of the cell. A model of a pressure cycled reactor has been constructed around the model of the cells. Tested against actual reactor fermentations, the model's predictions were in quantitative agreement. The model was used to computationally survey the relative utility of variations in system design and operating strategy, suggesting that increased mixing between the cell and nutrient layers and the use of a solvent with a distribution coefficient much higher than that of TBP would significantly improve productivity. The reactor has been operated continuously without failure for over 3000 hours, demonstrating that it can be run for the periods dictated by process economics. Two natural substrates were fermented in the reactor. Corn starch hydrolysate appears to be a highly suitable substrate, blackstrap molasses does not. Zymomonas mobilis was a less effective catalyst than Saccharomyces cerevisiae.

Steinmeyer, D.E.

1990-01-01

179

Materials experience and selection for nuclear materials production reactor heat exchangers  

SciTech Connect

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

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

1990-01-01

180

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

181

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

182

Parametric Evaluation of Large-Scale High-Temperature Electrolysis Hydrogen Production Using Different Advanced Nuclear Reactor Heat Sources  

SciTech Connect

High Temperature Electrolysis (HTE), when coupled to an advanced nuclear reactor capable of operating at reactor outlet temperatures of 800 C to 950 C, has the potential to efficiently produce the large quantities of hydrogen needed to meet future energy and transportation needs. To evaluate the potential benefits of nuclear-driven hydrogen production, the UniSim process analysis software was used to evaluate different reactor concepts coupled to a reference HTE process design concept. The reference HTE concept included an Intermediate Heat Exchanger and intermediate helium loop to separate the reactor primary system from the HTE process loops and additional heat exchangers to transfer reactor heat from the intermediate loop to the HTE process loops. The two process loops consisted of the water/steam loop feeding the cathode side of a HTE electrolysis stack, and the sweep gas loop used to remove oxygen from the anode side. The UniSim model of the process loops included pumps to circulate the working fluids and heat exchangers to recover heat from the oxygen and hydrogen product streams to improve the overall hydrogen production efficiencies. The reference HTE process loop model was coupled to separate UniSim models developed for three different advanced reactor concepts (a high-temperature helium cooled reactor concept and two different supercritical CO2 reactor concepts). Sensitivity studies were then performed to evaluate the affect of reactor outlet temperature on the power cycle efficiency and overall hydrogen production efficiency for each of the reactor power cycles. The results of these sensitivity studies showed that overall power cycle and hydrogen production efficiencies increased with reactor outlet temperature, but the power cycles producing the highest efficiencies varied depending on the temperature range considered.

Edwin A. Harvego; Michael G. McKellar; James E. O'Brien; J. Stephen Herring

2009-09-01

183

Micro-structured nuclear fuel and novel nuclear reactor concepts for advanced power production  

Microsoft Academic Search

Many applications (e.g. terrestrial and space electric power production, naval, underwater and railroad propulsion and auxiliary power for isolated regions) require a compact-high-power electricity source. The development of such a reactor structure necessitates a deeper understanding of fission energy transport and materials behavior in radiation dominated structures. One solution to reduce the greenhouse-gas emissions and delay the catastrophic events' occurrences

Liviu Popa-Simil

2008-01-01

184

Modeling requirements for full-scope reactor simulators of fission-product transport during severe accidents  

SciTech Connect

This paper describes in the needs and requirements to properly and efficiently model fission product transport on full scope reactor simulators. Current LWR simulators can be easily adapted to model severe accident phenomena and the transport of radionuclides. Once adapted these simulators can be used as a training tool during operator training exercises for training on severe accident guidelines, for training on containment venting procedures, or as training tool during site wide emergency training exercises.

Ellison, P.G.; Monson, P.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Mitchell, H.A. [Concord Associates, Inc., Knoxville, TN (United States)

1990-12-31

185

Modeling requirements for full-scope reactor simulators of fission-product transport during severe accidents  

SciTech Connect

This paper describes in the needs and requirements to properly and efficiently model fission product transport on full scope reactor simulators. Current LWR simulators can be easily adapted to model severe accident phenomena and the transport of radionuclides. Once adapted these simulators can be used as a training tool during operator training exercises for training on severe accident guidelines, for training on containment venting procedures, or as training tool during site wide emergency training exercises.

Ellison, P.G.; Monson, P.R. (Westinghouse Savannah River Co., Aiken, SC (United States)); Mitchell, H.A. (Concord Associates, Inc., Knoxville, TN (United States))

1990-01-01

186

Effective, routine reactor production method of ¹⁸F for medical use  

Microsoft Academic Search

An effective and rapid method for the reactor production of ¹⁸F ; for medical use is described. The ¹⁸F is produced by neutron irradiation ; of enriched lithium carbonate and is separated by the distillation procedure. ; The chemical yield at the end of the separation procedure is better than 95%. ; About 15 to 20 mCi of carrier-free ¹⁸F

F. Helus; O. Krauss; W. Maier-Borst

1973-01-01

187

Performance test of a 6-stage continuous reactor for palm methyl ester production  

Microsoft Academic Search

Effects of residence time (312min), stirrer speed (0800rpm), and NaOH concentration (0.251.0wt% of oil) on the production performance of the designed 6-stage continuous reactor (2.272l) for transesterification of palm oil were investigated at molar ratio of methanol to oil of 6:1 and temperature of 60C. Higher stirrer speed increased the reaction rate up to an appropriate speed but excessive stirrer

T. Leevijit; C. Tongurai; G. Prateepchaikul; W. Wisutmethangoon

2008-01-01

188

High-temperature reactor fuel fission product release and distribution at 1600 to 1800 degrees C  

Microsoft Academic Search

The essential feature of small, modular high-temperature reactors (HTRs) is the inherent limitation in maximum accident temperature to below 1600° C combined with the ability of coated particle fuel to retain all safety-relevant fission products under these conditions. To demonstrate this ability, spherical fuel elements with modern TRISO particles are irradiated and subjected to heating tests. Even after extended heating

W. Schenk; H. Nabielek

1991-01-01

189

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.

2012-01-01

190

Enhanced pullulan production in a biofilm reactor by using response surface methodology  

Microsoft Academic Search

Pullulan is a linear homopolysaccharide that is composed of glucose units and often described as ?-1, 6-linked maltotriose.\\u000a In this study, response surface methodology using BoxBehnken design was employed to study the effects of sucrose and nitrogen\\u000a concentrations on pullulan production. A total of 15 experimental runs were carried out in a plastic composite support biofilm\\u000a reactor. Three-dimensional response surface

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

2010-01-01

191

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

2013-01-01

192

Development of a phenomena identification and ranking table for a postulated double-ended guillotine break in a production reactor  

Microsoft Academic Search

In the wake of the Chernobyl accident, production reactors in the United States have come under increasing scrutiny with respect to safe operation. Because of additional design features, the U.S. reactors are considered inherently more safe than was the Chernobyl design. However, demonstration of their safety margins is required. The U.S. Nuclear Regulatory Commission has developed a generic methodology (code

R. G. Hanson; G. E. Wilson; M. G. Ortiz; D. P. Griggs

1989-01-01

193

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 540C and 900C, 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

194

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

SciTech Connect

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

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

2010-12-01

195

Pipeline Accident Report. Lone Star Gas Company North Richland Hills, Texas, October 4, 1971.  

National Technical Information Service (NTIS)

At about 4:45 a.m., on October 4, 1971, a small explosion and intense fire completely destroyed a house at 8300 Jerrie Jo Drive in North Richland Hills, Texas. This accident caused the deaths of a father and his two sons and the severe burning of their mo...

1972-01-01

196

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

NASA Astrophysics Data System (ADS)

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

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

2000-04-01

197

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

PubMed

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

Cadavid-Rodrguez, Luz Stella; Horan, Nigel J

2014-09-01

198

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

199

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

200

Simulation of methane conversion to syngas in a membrane reactor: Part I A model including product oxidation  

Microsoft Academic Search

A one-dimensional dense membrane reactor (DMR) model has been developed to simulate the partial oxidation of methane to syngas. A combustionreforming mechanism was adopted and the oxidation of reforming products, i.e. H2 and CO, was considered. The performance of the DMR and a conventional fixed-bed reactor was compared and discussed. The results show that the incorporation of the product oxidation

Zebao Rui; Ke Zhang; Yongdan Li; Y. S. Lina

2008-01-01

201

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

202

Modeling the behavior of a light-water production reactor target rod  

SciTech Connect

Pacific Northwest Laboratory has been conducting a series of in-reactor experiments in the Idaho National Engineering Laboratory (INEL) Advanced Test Reactor (ATR) to determine the amount of tritium released by permeation from a target rod under neutron irradiation. The model discussed in this report was developed from first principles to model the behavior of the first target rod irradiated in the ATR. The model can be used to determine predictive relationships for the amount of tritium that permeates through the target rod cladding during irradiation. The model consists of terms and equations for tritium production, gettering, partial pressure, and permeation, all of which are described in this report. The model addressed only the condition of steady state and features only a single adjustable parameter. The target rod design for producing tritium in a light-water reactor was tested first in the WC-1 in-reactor experiment. During irradiation, tritium is generated in the target rod within the ceramic lithium target material. The target rod has been engineered to limit the release of tritium to the reactor coolant during normal operations. The engineered features are a nickel-plated Zircaloy-4 getter and a barrier coating on the cladding surfaces. The ceramic target is wrapped with the getter material and the resulting ``pencils`` are inserted into the barrier coated cladding. These features of the rod are described in the report, along with the release of tritium from the ceramic target. The steady-state model could be useful for the design procedure of target rod components.

Sherwood, D.J.

1992-03-01

203

Modeling the behavior of a light-water production reactor target rod  

SciTech Connect

Pacific Northwest Laboratory has been conducting a series of in-reactor experiments in the Idaho National Engineering Laboratory (INEL) Advanced Test Reactor (ATR) to determine the amount of tritium released by permeation from a target rod under neutron irradiation. The model discussed in this report was developed from first principles to model the behavior of the first target rod irradiated in the ATR. The model can be used to determine predictive relationships for the amount of tritium that permeates through the target rod cladding during irradiation. The model consists of terms and equations for tritium production, gettering, partial pressure, and permeation, all of which are described in this report. The model addressed only the condition of steady state and features only a single adjustable parameter. The target rod design for producing tritium in a light-water reactor was tested first in the WC-1 in-reactor experiment. During irradiation, tritium is generated in the target rod within the ceramic lithium target material. The target rod has been engineered to limit the release of tritium to the reactor coolant during normal operations. The engineered features are a nickel-plated Zircaloy-4 getter and a barrier coating on the cladding surfaces. The ceramic target is wrapped with the getter material and the resulting pencils'' are inserted into the barrier coated cladding. These features of the rod are described in the report, along with the release of tritium from the ceramic target. The steady-state model could be useful for the design procedure of target rod components.

Sherwood, D.J.

1992-03-01

204

Licensing for tritium production in a commercial light water reactor: A utility view  

SciTech Connect

In a December 1995 Record of Decision for the Final Programmatic Environmental Impact Statement for Tritium Supply and Recycling, the US Department of Energy (DOE) decided to pursue a dual-track approach to determine the preferred option for future production of tritium for the nuclear weapons stockpile. The two options to be pursued were (a) the Accelerator Production of Tritium and (b) the use of commercial light water reactors (CLWRs). DOE committed to select one of these two options as the primary means of tritium production by the end of 1998. The other option would continue to be pursued as a backup to the primary option. The Tennessee Valley Authority (TVA) became involved in the tritium program in early 1996, in response to an inquiry from Pacific Northwest National Laboratory (PNNL) for an expression of interest by utilities operating nuclear power plants (NPPs). In June 1996, TVA was one of two utilities to respond to a request for proposals to irradiate lead test assemblies (LTAs) containing tritium-producing burnable absorber rods (TPBARs). TVA proposed that the LTAs be placed in Watts Bar NPP Unit 1 (WBN). TVA participated with DOE (the Defense Programs Office of CLWR Tritium Production), PNNL, and Westinghouse Electric Company (Westinghouse) in the design process to ensure that the TPBARs would be compatible with safe operation of WBN. Following US Nuclear Regulatory Commission (NRC) issuance of a Safety Evaluation Report (SER) (NUREG-1607), TVA submitted a license amendment request to the NRC for approval to place four LTAs, containing eight TPBARs each, in WBN during the September 1997 refueling outage. In December 1998, DOE announced the selection of the CLWR program as the primary option for tritium production and identified the TVA WBN and Sequoyah NPP (SQN) Units 1 and 2 (SQN-1 and SQN-2, respectively) reactors as the preferred locations to perform tritium production. TVA will prepare license amendment requests for the three plants (WBN, SQN-1, and SQN-2). While the TPBARs replace discreet burnable absorbers in the reactor cores, there are differences in the reactions that occur in the absorber material (lithium aluminate versus boron). At end of life, the lithium aluminate provides considerably more reactivity holddown than the standard boron-containing burnable absorbers. Therefore, it will be necessary for the TVA plant engineering and fuels staffs, working with the fuel vendors, to define the appropriate core loading (number of fresh fuel assemblies, enrichment, etc.) to maintain safe operating limits under both operating and accident conditions. It is recognized that the irradiation of TPBARs in the TVA reactors will also require additional radiological and chemistry program upgrades.

Chardos, J.S.; Sorensen, G.C.; Erickson, L.W.

2000-07-01

205

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

PubMed

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

206

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.

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

2009-01-01

207

Lithium doping of candidate fusion reactor alloys to simulate simultaneous helium and damage production  

NASA Astrophysics Data System (ADS)

Lithium and boron doping techniques are possibilities for simulating simultaneous helium production and displacement damage in bulk specimens of non-nickel bearing materials in fast fission reactors. Rapid solidification processing and powder metallurgy salt decomposition were investigated for the preparation of lithium doped alloys. For convenience, austenitic stainless steel was doped rather than non-nickel bearing alloys for which this technique is ultimately designed. Neutron autoradiography verified a uniform distribution of lithium in the alloy. Although the same approach can be used to dope alloys uniformly with a stable boron compound, thus reducing the problem of grain boundary segregation and coarsening, the use of lithium doping should be an advantage because this dopant produces only helium and hydrogen when irradiated in a fast fission reactor. These elements are also produced in materials in the CTR environment.

Megusar, J.; Harling, O. K.; Grant, N. J.

1983-04-01

208

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; Ibez, Maria; Carrete, Alex; Cabot, Andreu

2012-01-25

209

Fermentative hydrogen production from molasses wastewater in a continuous mixed immobilized sludge reactor.  

PubMed

A novel continuous mixed immobilized sludge reactor (CMISR) containing activated carbon as support carrier was used for fermentative hydrogen production from molasses wastewater. When the CMISR system operated at the conditions of influent COD of 2000-6000mg/L, hydraulic retention time (HRT) of 6h and temperature of 35C, stable ethanol type fermentation was formed after 40days operation. The H(2) content in biogas and chemical oxygen demand (COD) removal were estimated to be 46.6% and 13%, respectively. The effects of organic loading rates (OLRs) on the CMISR hydrogen production system were also investigated. It was found that the maximum hydrogen production rate of 12.51mmol/hL was obtained at OLR of 32kg/m(3)d and the maximum hydrogen yield by substrate consumed of 130.57mmol/mol happened at OLR of 16kg/m(3)d. Therefore, the continuous mixed immobilized sludge reactor (CMISR) could be a promising immobilized system for fermentative hydrogen production. PMID:22326329

Han, Wei; Wang, Bing; Zhou, Yan; Wang, De-Xin; Wang, Yan; Yue, Li-Ran; Li, Yong-Feng; Ren, Nan-Qi

2012-04-01

210

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

SciTech Connect

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

N /A

1999-03-12

211

Isotope production target irradiation experience at the annular core research reactor  

SciTech Connect

As a result of an Environmental Impact Statement (EIS) recently issued by the Department of Energy, Sandia National Laboratories (SNL) has been selected as the {open_quotes}most appropriate facility{close_quotes} for the production of {sup 99}Mo. The daughter product of {sup 99}Mo is {sup 99m}Tc, a radioisotope used in 36,000 medical procedures per day in the U.S.{close_quote} At SNL, the {sup 99}Mo would be created by the fission process in UO{sub 2} coated {open_quotes}targets{close_quotes} and chemically separated in the SNL Hot Cell Facility (HCF). SNL has recently completed the irradiation of five production targets at its Annular Core Research Reactor (ACRR). Following irradiation, four of the targets were chemically processed in the HCF using the Cintichem process.

Talley, D.G.

1997-02-01

212

ACRR (Annular Core Research Reactor) fission product release tests: ST-1 and ST-2  

SciTech Connect

Two experiments (ST-1 and ST-2) have been performed in the Annular Core Research Reactor (ACER) at Sandia National Laboratories (SNLA) to obtain time-resolved data on the release of fission products from irradiated fuels under light water reactor (LWR) severe accident conditions. Both experiments were conducted in a highly reducing environment at maximum fuel temperatures of greater than 2400 K. These experiments were designed specifically to investigate the effect of increased total pressure on fission product release; ST-1 was performed at approximately 0.16 MPa and ST-2 was run at 1.9 MPa, whereas other parameters were matched as closely as possible. Release rate data were measured for Cs, I, Ba, Sr, Eu, Te, and U. The release rates were higher than predicted by existing codes for Ba, Sr, Eu, and U. Te release was very low, but Te did not appear to be sequestered by the zircaloy cladding; it was evenly distributed in the fuel. In addition, in posttest analysis a unique fuel morphology (fuel swelling) was observed which may have enhanced fission product release, especially in the high pressure test (ST-2). These data are compared with analytical results from the CORSOR correlation and the VICTORIA computer model. 8 refs., 8 figs., 2 tabs.

Allen, M.D.; Stockman, H.W.; Reil, K.O.; Grimley, A.J.; Camp, W.J.

1988-01-01

213

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

SciTech Connect

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

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

1994-11-01

214

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

215

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

NASA Astrophysics Data System (ADS)

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

Sun, May Yongmei

216

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

217

First production of ultracold neutrons with a solid deuterium source at the pulsed reactor TRIGA Mainz ?  

Microsoft Academic Search

.The production rates of ultracold neutrons (UCN) with a solid deuterium converter have been measured at the pulsed reactor\\u000a TRIGA Mainz. Exposed to a thermal neutron fluence of \\u000a \\u000a n?cm^-2?pulse^-1, the number of detected very cold and ultracold neutrons ranges up to 200 000 at 7mol of solid deuterium\\u000a (sD2) in combination with a pre-moderator (mesitylene). About 50% of the measured

A. Frei; Yu. Sobolev; I. Altarev; K. Eberhardt; A. Gschrey; E. Gutsmiedl; R. Hackl; G. Hampel; F. J. Hartmann; W. Heil; J. V. Kratz; Th. Lauer; A. Li?on Aguilar; A. R. Mller; S. Paul; Yu. Pokotilovski; W. Schmid; L. Tassini; D. Tortorella; N. Trautmann; U. Trinks; N. Wiehl

2007-01-01

218

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

PubMed

A feasibility study for (131)I production using a Low Power Research Reactor was conducted to predict the yield of (131)I by cyclic activation technique. A maximum activity of 5.1GBq was achieved through simulation using FORTRAN 90, for an irradiation of 6h. But experimentally only 4h irradiation could be done, which resulted in an activity of 4.010(5)Bq. The discrepancy in the activities was due to the fact that beta decays released during the process could not be considered. PMID:21900016

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

2012-01-01

219

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

220

Membrane reactor microstructure for polymer grade olefin production and hydrogen cogeneration.  

PubMed

The current communication describes research work on effective membrane reactor nanostructures and nanoreaction-nanoseparation technology for polymer grade olefin production via catalytic paraffin dehydrogenation reactions. Emphasis is given in systems of permreactors and permeators to perform the described reactive and separative operations. We elaborate on new membrane microstructure designs for paraffin dehydrogenations including the design of experiments, operation, and best parameter selection and optimization of such systems. The described processes are of current significance in the area of new microreactor design and operation including hydrocarbon processing and conversion to valuable fuels and chemicals such as hydrogen, olefins, and polyolefins. These improved results are because of the unique design characteristics of the examined microreactor systems to perform accurate multiphase and heterogeneous functions into one unit operation. A number of membrane reactor configurations were made and tested on stream for the catalytic propane dehydrogenation reaction to propylene with successful results. Some of the results are discussed below which show the better performance of nanostructured membrane reactors for the specific dehydrogenation. PMID:21133187

Ziaka, Zoe D; Navrozidou, Anna; Paraschopoulou, Louisa; Vasileiadis, Savvas P

2010-09-01

221

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

222

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/Bs) 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

223

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/Bs) 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

224

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

SciTech Connect

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

N /A

2001-10-10

225

A physical description of fission product behavior fuels for advanced power reactors.  

SciTech Connect

The Global Nuclear Energy Partnership (GNEP) is considering a list of reactors and nuclear fuels as part of its chartered initiative. Because many of the candidate materials have not been explored experimentally under the conditions of interest, and in order to economize on program costs, analytical support in the form of combined first principle and mechanistic modeling is highly desirable. The present work is a compilation of mechanistic models developed in order to describe the fission product behavior of irradiated nuclear fuel. The mechanistic nature of the model development allows for the possibility of describing a range of nuclear fuels under varying operating conditions. Key sources include the FASTGRASS code with an application to UO{sub 2} power reactor fuel and the Dispersion Analysis Research Tool (DART ) with an application to uranium-silicide and uranium-molybdenum research reactor fuel. Described behavior mechanisms are divided into subdivisions treating fundamental materials processes under normal operation as well as the effect of transient heating conditions on these processes. Model topics discussed include intra- and intergranular gas-atom and bubble diffusion, bubble nucleation and growth, gas-atom re-solution, fuel swelling and ?scion gas release. In addition, the effect of an evolving microstructure on these processes (e.g., irradiation-induced recrystallization) is considered. The uranium-alloy fuel, U-xPu-Zr, is investigated and behavior mechanisms are proposed for swelling in the {alpha}-, intermediate- and {gamma}-uranium zones of this fuel. The work reviews the FASTGRASS kinetic/mechanistic description of volatile ?scion products and, separately, the basis for the DART calculation of bubble behavior in amorphous fuels. Development areas and applications for physical nuclear fuel models are identified.

Kaganas, G.; Rest, J.; Nuclear Engineering Division; Florida International Univ.

2007-10-18

226

Fermentative hydrogen production from beet sugar wastewater in a continuous stirred tank reactor (CSTR): Effect of hydraulic retention time (HRT)  

Microsoft Academic Search

The effect of hydraulic retention time (HRT) on the performance of hydrogen production from beet sugar wastewater by anaerobic fermentation using mixed microbial communities was investigated in a continuous stirred-tank reactor (CSTR) in this present study. A CSTR was designed and its performance was determined at various HRT. The goal was to find the optimal HRT for hydrogen production, to

Huixia Jin; Huizheng Jin

2010-01-01

227

Migration paths for Oklo reactor products and applications to the problem of geological storage of nuclear wastes  

Microsoft Academic Search

Escape of the products from the Oklo reactor proceeds, first, by escape from the uraninite (UO) grains and, second, by transport out of the gangue. Escape from the grain by fission recoil accounts for prompt deposition in the gangue of 5 to 10 percent of the products. Escape by volume diffusion is very slow. The rate of loss by diffusion

1977-01-01

228

Production Test IP502-I calibration of gas monitoring instrumentation to measure the amount of oxygen in a reactor  

Microsoft Academic Search

This production test is designed to test the feasibility of controlling the amount of air entering a reactor, hence, the burnout of the graphite by monitoring the gas activity. Gas activity comes from the induced activity on argon, which is one of the constituents of air. This production test is basically a test to calibrate the gas activity instruments as

Smit

1962-01-01

229

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

SciTech Connect

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

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

2008-01-01

230

Biogas production from potato-juice, a by-product from potato-starch processing, in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors.  

PubMed

In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470 mL-CH(4)/gVS-added. Anaerobic digestion of potato-juice in an EGSB reactor could obtain a methane yield of 380 mL-CH(4)/gVS-added at the organic loading rate of 3.2 gCOD/(L-reactor.d). In a UASB reactor, higher organic loading rate of 5.1 gCOD/(L-reactor.d) could be tolerated, however, it resulted in a lower methane yield of 240 mL-CH(4)/gVS-added. The treatment of reactor effluent was also investigated. By acidification with sulfuric acid to pH lower than 5, almost 100% of the ammonia content in the effluent could be retained during the successive up-concentration process step. The reactor effluent could be up-concentrated by evaporation to minimize its volume, and later be utilized as fertilizer. PMID:21450459

Fang, Cheng; Boe, Kanokwan; Angelidaki, Irini

2011-05-01

231

Double-ended break probability estimate for the 304 stainless steel main circulation piping of a production reactor  

SciTech Connect

The large break frequency resulting from intergranular stress corrosion cracking in the main circulation piping of the Savannah River Site (SRS) production reactors has been estimated. Four factors are developed to describe the likelihood that a crack exists that is not identified by ultrasonic inspection, and that grows to instability prior to growing through-wall and being detected by the ensuing leakage. The estimated large break frequency is 3.4 {times} 10{sup {minus}8} per reactor-year.

Mehta, H.S. (General Electric Co., San Jose, CA (United States)); Daugherty, W.L.; Awadalla, N.G.; Sindelar, R.L. (Westinghouse Savannah River Co., Aiken, SC (United States))

1991-01-01

232

Double-ended break probability estimate for the 304 stainless steel main circulation piping of a production reactor  

SciTech Connect

The large break frequency resulting from intergranular stress corrosion cracking in the main circulation piping of the Savannah River Site (SRS) production reactors has been estimated. Four factors are developed to describe the likelihood that a crack exists that is not identified by ultrasonic inspection, and that grows to instability prior to growing through-wall and being detected by the ensuing leakage. The estimated large break frequency is 3.4 {times} 10{sup {minus}8} per reactor-year.

Mehta, H.S. [General Electric Co., San Jose, CA (United States); Daugherty, W.L.; Awadalla, N.G.; Sindelar, R.L. [Westinghouse Savannah River Co., Aiken, SC (United States)

1991-12-31

233

Gasification of refuse derived fuel in a fixed bed reactor for syngas production  

SciTech Connect

Steam gasification of two different refuse derived fuels (RDFs), differing slightly in composition as well as thermal stability, was carried out in a fixed-bed reactor at atmospheric pressure. The proximate and ultimate analyses reveal that carbon and hydrogen are the major components in RDFs. The thermal analysis indicates the presence of cellulose and plastic based materials in RDFs. H{sub 2} and CO are found to be the major products, along with CO{sub 2} and hydrocarbons resulting from gasification of RDFs. The effect of gasification temperature on H{sub 2} and CO selectivities was studied, and the optimum temperature for better H{sub 2} and CO selectivity was determined to be 725 deg. C. The calorific value of product gas produced at lower gasification temperature is significantly higher than that of gas produced at higher process temperature. Also, the composition of RDF plays an important role in distribution of products gas. The RDF with more C and H content is found to produce more amounts of CO and H{sub 2} under similar experimental conditions. The steam/waste ratio showed a notable effect on the selectivity of syngas as well as calorific value of the resulting product gas. The flow rate of carrier gas did not show any significant effect on products yield or their distribution.

Dalai, Ajay K. [Catalysis and Chemical Reaction Engineering Laboratories, Department of Chemical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9 (Canada)], E-mail: ajay.dalai@usask.ca; Batta, Nishant [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9 (Canada); Eswaramoorthi, I. [Catalysis and Chemical Reaction Engineering Laboratories, Department of Chemical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9 (Canada); Schoenau, Greg J. [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9 (Canada)

2009-01-15

234

Gasification of refuse derived fuel in a fixed bed reactor for syngas production.  

PubMed

Steam gasification of two different refuse derived fuels (RDFs), differing slightly in composition as well as thermal stability, was carried out in a fixed-bed reactor at atmospheric pressure. The proximate and ultimate analyses reveal that carbon and hydrogen are the major components in RDFs. The thermal analysis indicates the presence of cellulose and plastic based materials in RDFs. H2 and CO are found to be the major products, along with CO2 and hydrocarbons resulting from gasification of RDFs. The effect of gasification temperature on H2 and CO selectivities was studied, and the optimum temperature for better H2 and CO selectivity was determined to be 725 degrees C. The calorific value of product gas produced at lower gasification temperature is significantly higher than that of gas produced at higher process temperature. Also, the composition of RDF plays an important role in distribution of products gas. The RDF with more C and H content is found to produce more amounts of CO and H2 under similar experimental conditions. The steam/waste ratio showed a notable effect on the selectivity of syngas as well as calorific value of the resulting product gas. The flow rate of carrier gas did not show any significant effect on products yield or their distribution. PMID:18434127

Dalai, Ajay K; Batta, Nishant; Eswaramoorthi, I; Schoenau, Greg J

2009-01-01

235

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

2011-01-01

236

Argon41 production and evolution at the Oregon State University TRIGA Reactor (OSTR)  

Microsoft Academic Search

In this study, argon-41 concentrations were measured at various locations within the reactor facility to assess the accuracy of models used to predict argon-41 evolution from the reactor tank, and to determine the relationship between argon gas evolution from the tank and subsequent argon-41 concentrations throughout the reactor room. In particular, argon-41 was measured directly above the reactor tank with

L. G. Anellis; A. G. Johnson; J. F. Higginbotham

1988-01-01

237

Integration of continuous production and recovery of solvents from whey permeate: use of immobilized cells of Clostridium acetobutylicum in a flutilized bed reactor coupled with gas stripping  

Microsoft Academic Search

An investigation was performed into the operation of an integrated system for continuous production and product recovery of solvents (acetone-butanol-ethanol) from the ABE fermentation process. Cells of Clostridium acetobutylicum were immobilized by adsorption onto bonechar, and used in a fluidized bed reactor for continuous solvent production from whey permeate. The reactor effluent was stripped of the solvents using nitrogen gas,

N. Qureshi; I. S. Maddox

1990-01-01

238

Effects of pH profiles on nisin production in biofilm reactor.  

PubMed

Apart from its widely accepted commercial applications as a food preservative, nisin emerges as a promising alternative in medical applications for bacterial infection in both humans and livestock. Improving nisin production through optimization of fermentation parameters would make nisin more cost-effective for various applications. Since nisin production by Lactococcus lactis NIZO 22186 was highly influenced by the pH profile employed during fermentation, three different pH profiles were evaluated in this study: (1) a constant pH profile at 6.8 (profile 1), (2) a constant pH profile with autoacidification at 4 h (profile 2), and (3) a stepwise pH profile with pH adjustment every 2 h (profile 3). The results demonstrated that the low-pH stress exerted during the first 4 h of fermentation in profile 3 detrimentally affected nisin production, resulting in a very low maximum nisin concentration (593 IU ml(-1)). On the other hand, growth and lactic acid production were only slightly delayed, indicating that the loss in nisin production was not a result of lower growth or shifting of metabolic activity toward lactic acid production. Profile 2, in which pH was allowed to drop freely via autoacidification after 4 h of fermentation, was found to yield almost 1.9 times higher nisin (3,553 IU ml(-1)) than profile 1 (1,898 IU ml(-1)), possibly as a result of less adsorption of nisin onto producer cells. Therefore, a combination of constant pH and autoacidification period (profile 2) was recommended as the pH profile during nisin production in a biofilm reactor. PMID:16331455

Pongtharangkul, Thunyarat; Demirci, Ali

2006-08-01

239

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

PubMed

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

Christenson, Logan B; Sims, Ronald C

2012-07-01

240

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

241

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 25ml/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

242

The two stage immobilized column reactor with an integrated solvent recovery module for enhanced ABE production.  

PubMed

The production of acetone, butanol, and ethanol (ABE) by fermentation is a process that had been used by industries for decades. Two stage immobilized column reactor system integrated with liquid-liquid extraction was used with immobilized Clostridium acetobutylicum DSM 792, to enhance the ABE productivity and yield. The sugar mixture (glucose, mannose, galactose, arabinose, and xylose) representative to the lignocellulose hydrolysates was used as a substrate for continuous ABE production. Maximum total ABE solvent concentration of 20.30 g L(-1) was achieved at a dilution rate (D) of 0.2h(-1), with the sugar mixture as a substrate. The maximum solvent productivity (10.85 g L(-1)h(-1)) and the solvent yield (0.38 g g(-1)) were obtained at a dilution rate of 1.0 h(-1). The maximum sugar mixture utilization rate was achieved with the present set up which is difficult to reach in a single stage chemostat. The system was operated for 48 days without any technical problems. PMID:23708785

Bankar, Sandip B; Survase, Shrikant A; Ojamo, Heikki; Granstrm, Tom

2013-07-01

243

Biohydrogen production from ethanol-type fermentation of molasses in an expanded granular sludge bed (EGSB) reactor  

Microsoft Academic Search

An expanded granular sludge bed (EGSB) process with granular activated carbon (GAC) was developed for fermentative hydrogen production from molasses-containing wastewater by mixed microbial cultures. No pH regulation was performed during the whole operation period. Running at the temperature of 35C, the EGSB reactor presented a high hydrogen production ability as the hydrogen production rate (HPR) maximized at 0.71L\\/Lh. At

Wan-Qian Guo; Nan-Qi Ren; Xiang-Jing Wang; Wen-Sheng Xiang; Zhao-Hui Meng; Jie Ding; Yuan-Yuan Qu; Lu-Si Zhang

2008-01-01

244

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

SciTech Connect

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

Cronenberg, A.W. (Engineering Science and Analysis, Albuquerque, NM (USA)); Hyder, M.L.; Ellison, P.G. (Westinghouse Savannah River Co., Aiken, SC (USA))

1990-01-01

245

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

PubMed

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

Ellens, C J; Brown, R C

2012-01-01

246

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

247

Biogas production from potato-juice, a by-product from potato-starch processing, in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors  

Microsoft Academic Search

In this study, the utilization of potato-juice, the organic by-product from potato-starch processing, for biogas production was investigated in batch assay and in high rate anaerobic reactors. The maximum methane potential of the potato-juice determined by batch assay was 470mL-CH4\\/gVS-added. Anaerobic digestion of potato-juice in an EGSB reactor could obtain a methane yield of 380mL-CH4\\/gVS-added at the organic loading rate

Cheng Fang; Kanokwan Boe; Irini Angelidaki

2011-01-01

248

Biohydrogen production in continuous-flow reactor using mixed microbial culture.  

PubMed

The goal of the proposed project was to develop an anaerobic fermentation process that converts negative-value organic wastes into hydrogen-rich gas in a continuous-flow reactor under different operating conditions, such as hydraulic retention time (HRT), heat treatment, pH, and substrates. A series of batch tests were also conducted in parallel to the continuous study to evaluate the hydrogen conversion efficiency of two different organic substrates, namely sucrose and starch. A heat shock (at 90 degrees C for 15 minutes) was applied to the sludge in an external heating chamber known as a sludge activation chamber, as a method to impose a selection pressure to eliminate non-spore-forming, hydrogen-consuming bacteria and to activate spore germination. The experimental results showed that the heat activation of biomass enhanced hydrogen production by selecting for hydrogen-producing, spore-forming bacteria. The batch feeding at a shorter HRT of 20 hours (or higher organic loading rate) favored hydrogen production, whereas, at a longer HRT of 30 hours, methane was detected in the gas phase. The major organic acids of hydrogen fermentation were acetate, butyrate, and propionate. Up to 23.1% of influent chemical oxygen demand was consumed in biomass synthesis. Batch tests showed that the hydrogen-production potential of starch was lower than sucrose, and better conversion efficiency from starch was obtained at a lower pH of 4.5. However, addition of sucrose to starch improved the overall hydrogen-production potential and hydrogen-production rate. This study showed that sustainable biohydrogen production from carbohydrate-rich substrates is possible through heat activation of settled sludge. PMID:16566518

Khanal, Samir Kumar; Chen, Wen-Hsing; Li, Ling; Sung, Shihwu

2006-02-01

249

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

250

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

251

Analysis of the Effects of Radiolytic-Gas Bubbles on the Operation of Solution Reactors for the Production of Medical Isotopes  

SciTech Connect

One of the primary methods to produce medical isotopes, such as {sup 99}Mo, is by irradiation of uranium targets in heterogeneous reactors. Solution reactors present a potential alternative to produce medical isotopes. The Medical Isotope Production Reactor (MIPR) concept has been proposed to produce medical isotopes with lower uranium consumption and waste than those in heterogeneous reactors. Commercial production of medical isotopes in solution reactors requires steady-state operation at {approx}200 kW. At this power regime, fuel-solution temperature increase and radiolytic-gas bubble formation introduce a negative reactivity feedback that has to be mitigated. A model based on the point reactor kinetic equations has been developed to investigate these reactivity effects. This model has been validated against experimental results from the Los Alamos National Laboratory uranyl fluoride Solution High-Energy Burst Assembly (SHEBA) and shows the feasibility of solution reactors for the commercial production of medical isotopes.

Souto, Francisco J.; Kimpland, Robert H.; Heger, A. Sharif [Los Alamos National Laboratory (United States)

2005-07-15

252

Biodiesel production in a membrane reactor using MCM-41 supported solid acid catalyst.  

PubMed

Production of biodiesel from the transesterification between soybean oil and methanol was conducted in this study by a membrane reactor, in which ceramic membrane was packed with MCM-41 supported p-toluenesulfonic acid (PTSA). Box-Behnken design and response surface methodology (RSM) were used to investigate the effects of reaction temperature, catalyst amount and circulation velocity on the yield of biodiesel. A reduced cubic model was developed to navigate the design space. Reaction temperature was found to have most significant effect on the biodiesel yield while the interaction of catalyst amount and circulation velocity have minor effect on it. 80C of reaction temperature, 0.27 g/cm(3) of catalyst amount and 4.15 mL/min of circulation velocity were proved to be the optimum conditions to achieve the highest biodiesel yield. PMID:24657760

Xu, Wei; Gao, Lijing; Wang, Songcheng; Xiao, Guomin

2014-05-01

253

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

SciTech Connect

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

Hyder, M.L.; Ellison, P.G. (Westinghouse Savannah River Co., Aiken, SC (USA)); Cronenberg, A.W. (Engineering Science and Analysis, Albuquerque, NM (USA))

1990-01-01

254

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

NASA Astrophysics Data System (ADS)

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

Orlov, Andrey; Degueldre, Claude; Kaufmann, Wilfried

2013-01-01

255

Synthetic fuel production in a particle-beam driven fusion reactor  

NASA Astrophysics Data System (ADS)

An overview of the operation of an inertial confinement fusion reactor is presented explaining in particular the function of a buffer gas in the reaction chamber. The use of water vapor and carbon dioxide as a buffer gas are discussed with the intention of showing that they not only perform as buffer gases, but produce hydrogen and carbon monoxide as synthetic fuels as well when carbon dust is introduced with these feed gases. Equilibrium calculations for carbon dust and water vapor are performed for temperatures of 2000 and 4500 K and for carbon dust and carbon dioxide at 3500 K. The conversion times for 15-micron-diameter carbon particles were calculated using a shrinking core model. Tritium contamination of the products is also discussed.

Fisk, J. W.; Woodall, D. M.

256

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

257

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

258

Biological surfactant production in a biological slurry reactor treating diesel fuel contaminated soil.  

PubMed

A sandy loam with aged diesel fuel contamination was treated for 90 days in an 8-L soil slurry-sequencing batch reactor (SS-SBR). The purpose was to investigate biological surfactant production and its effect on slurry properties and reactor performance. The SS-SBR was operated with a 10-day retention time and a 5-day cycle. Track studies were performed to monitor the fluctuation in slurry properties during a single cycle. Surfactants were produced faster than they were degraded or sorbed during the first 1.5 days of each cycle, resulting in increasing concentrations from less than the critical micelle concentration (CMC) to 60 times the CMC and an increase in aqueous diesel fuel concentration from 0 to 1.2 g/L. Only after the concentration of surfactants and emulsified diesel fuel began to decrease through biodegradation (after 1.5 days) was foaming observed. Foam thickness increased from 0 mm at 1.5 days to 48 mm on day 3, and then decreased to 0 mm again by the end of the cycle. Surfactants were completely degraded by the end of each cycle. Coinciding profiles of foam thickness and emulsification capacity (i.e., ability to emulsify spiked hydrocarbon) indicate that foaming resulted from the temporary accumulation of free surfactant molecules. Biological surfactant production occurred without cell multiplication during the first day, but was later growth associated. The ratio of oxygen to diesel fuel consumed was 1.7, and the microorganism yield on a chemical oxygen demand basis (YCOD) was 0.43. PMID:11558308

Cassidy, D P

2001-01-01

259

Production of pyrolytic liquids from industrial sewage sludges in an induction-heating reactor.  

PubMed

With the application of induction-heating, the pyrolytic experiments have been carried out for three sewage sludges from the food processing factories in an externally heated fixed-bed reactor. The thermochemical characteristics of sludge samples were first analyzed. The results indicated that the calorific value had about 15 MJ/kg on an average, suggesting that it had a potential for biomass energy source. However, its nitrogen concentration was relatively high. From the thermogravimetric analysis (TGA) curves, it showed that the pyrolysis reaction can be almost finished in the temperature range of 450-750 degrees C. The yields of resulting liquid and char products from the pyrolysis of sewage sludge were discussed for examining the effects of pyrolysis temperature (500-800 degrees C), heating rate (200-500 degrees C/min), and holding time (1-8 min). Overall, the variation of yield was not so significant in the experimental conditions for three sewage sludges. All results of the resulting liquid products analyzed by elemental analyzer, pH meter, Karl-Fischer moisture titrator and bomb calorimeter were in consistence with those analyses by FTIR spectroscopy. Furthermore, the pyrolysis liquid products contained large amounts of water (>73% by weight) mostly derived from the bound water in the biosludge feedstocks and the condensation reactions during the pyrolysis reaction, and fewer contents of oxygenated hydrocarbons composing of carbonyl and nitrogen-containing groups, resulting in low pH and low calorific values. PMID:18656347

Tsai, Wen-Tien; Chang, Jeng-Hung; Hsien, Kuo-Jung; Chang, Yuan-Ming

2009-01-01

260

Analysis of fission product revaporization in a BWR reactor cooling system during a station blackout accident  

SciTech Connect

This report presents a preliminary analysis of fission product revaporization in the Reactor Cooling System (RCS) after the vessel failure. The station blackout transient for BWR Mark I Power Plant is considered. The TRAPMELT3 models of evaporization, chemisorption, and the decay heating of RCS structures and gases are adopted in the analysis. The RCS flow models based on the density-difference between the RCS and containment pedestal region are developed to estimate the RCS outflow which carries the revaporized fission product to the containment. A computer code called REVAP is developed for the analysis. The REVAP is incorporated with the MARCH, TRAPMELT3 and NAUA codes of the Source Term Code Pack Package (STCP). The NAUA code is used 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 determining the magnitude of revaporization and subsequent release of the volatile fission product. 8 figs., 1 tab.

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

1988-01-01

261

Variables that affect xylitol production from sugarcane bagasse hydrolysate in a zeolite fluidized bed reactor.  

PubMed

The operational conditions for xylitol production by fermentation of sugarcane bagasse hydrolysate in a fluidized bed reactor with cells immobilized on zeolite were evaluated. Fermentations were carried out under different conditions of air flowrate (0.0125-0.0375 vvm), zeolite mass (100-200 g), initial pH (4-6), and xylose concentration (40-60 g/L), according to a 2(4) full factorial design. The air flowrate increase resulted in a metabolic deviation from product to biomass formation. On the other hand, the pH increase favored both the xylitol yield (Y(P/S)) and volumetric productivity (Q(P)), and the xylose concentration increase positively influenced the xylitol concentration. The best operational conditions evaluated were based on the use of an air flowrate of 0.0125 vvm, 100 g of zeolite, pH 6, and xylose concentration of 60 g/L. Under these conditions, 38.5 g/L of xylitol were obtained, with a Y(P/S) of 0.72 g/g, Q(P) of 0.32 g/L.h, and cell retention of 25.9%. PMID:16321046

Santos, Jlio C; Mussatto, Solange I; Cunha, Mrio A A; Silva, Silvio S

2005-01-01

262

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

SciTech Connect

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

Wulff, W.

1990-01-01

263

High Velocity Continuous-Flow Reactor for the Production of Solar Grade Silicon.  

National Technical Information Service (NTIS)

The feasibility of a high volume, high velocity continuous reduction reactor as an economical means of producing solar grade silicon was tested. Bromosilanes and hydrogen were used as the feedstocks for the reactor along with preheated silicon particles w...

L. Woerner

1977-01-01

264

High Velocity Continuous-Flow Reactor for the Production of Solar Grade Silicon. First Quarterly Report.  

National Technical Information Service (NTIS)

This program is designed to test the feasibility of a high volume, high velocity continuous reduction reactor as an economical means of producing solar grade silicon. Bromosilanes and hydrogen are used as the feedstocks for the reactor along with preheate...

L. Woerner

1977-01-01

265

Development of a PIRT for a postulated double-ended guillotine break in a production reactor.  

National Technical Information Service (NTIS)

The US Nuclear Regulatory Commission has developed a generic methodology to quantify the uncertainty in best estimate computer codes used to license commercial light water reactors. This same methodology is equally applicable to other reactor designs with...

R. G. Hanson G. E. Wilson M. G. Ortiz D. P. Griggs

1989-01-01

266

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

PubMed

This study is aimed at estimating organic compounds removal and sludge production in SBR during treatment of landfill leachate. Four series were performed. At each series, experiments were carried out at the hydraulic retention time (HRT) of 12, 6, 3 and 2d. The series varied in SBR filling strategies, duration of the mixing and aeration phases, and the sludge age. In series 1 and 2 (a short filling period, mixing and aeration phases in the operating cycle), the relationship between organics concentration (COD) in the leachate treated and HRT was pseudo-first-order kinetics. In series 3 (with mixing and aeration phases) and series 4 (only aeration phase) with leachate supplied by means of a peristaltic pump for 4h of the cycle (filling during reaction period) - this relationship was zero-order kinetics. Activated sludge production expressed as the observed coefficient of biomass production (Y(obs)) decreased correspondingly with increasing HRT. The smallest differences between reactors were observed in series 3 in which Y(obs) was almost stable (0.55-0.6 mg VSS/mg COD). The elimination of the mixing phase in the cycle (series 4) caused the Y(obs) to decrease significantly from 0.32 mg VSS/mg COD at HRT 2d to 0.04 mg VSS/mg COD at HRT 12d. The theoretical yield coefficient Y accounted for 0.534 mg VSS/mg COD (series 1) and 0.583 mg VSS/mg COD (series 2). In series 3 and 4, it was almost stable (0.628 mg VSS/mg COD and 0.616 mg VSS/mg COD, respectively). After the elimination of the mixing phase in the operating cycle, the specific biomass decay rate increased from 0.006 d(-1) (series 3) to 0.032 d(-1) (series 4). The operating conditions employing mixing/aeration or only aeration phases enable regulation of the sludge production. The SBRs operated under aerobic conditions are more favourable at a short hydraulic retention time. At long hydraulic retention time, it can lead to a decrease in biomass concentration in the SBR as a result of cell decay. On the contrary, in the activated sludge at long HRT, a short filling period and operating cycle of the reactor with the mixing and aeration phases seem the most favourable. PMID:16289794

Klimiuk, Ewa; Kulikowska, Dorota

2006-01-01

267

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

PubMed

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

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

2013-09-01

268

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  

SciTech Connect

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 and posttest radiography, axial-power-profile variations, and power-coupling monitoring. High-quality results in fuel motion have been achieved, and motion sequences have been reconstructed in qualitative and quantitative visual forms. A collimated detection system has been used to observe fission products in the upper regions of a test loop in the TREAT reactor. Particular regions of the loop are targeted through any of five channels in a rotatable assembly in a horizontal hole through the biological shield. A well-type neutron detector, optimized for delayed neutrons, and two GeLi gamma ray spectrometers have been used in several experiments. Data are presented showing a time history of the transport of Dn emitters, of gamma spectra identifying volatile fission products deposited as aerosols, and of fission gas isotopes released from the coolant.

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

1986-05-01

269

NDE Assessments of Cast Stainless Steel Reactor Piping Components  

Microsoft Academic Search

Studies conducted at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, have focused on developing and evaluating the effectiveness and reliability of novel NDE approaches for the inspection of coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the United States Nuclear Regulatory Commission (US NRC) on the utility, effectiveness and

Aaron A. Diaz; Michael T. Anderson; Stephen E. Cumblidge; Steven R; Royce Mathews

2006-01-01

270

Dynamic Modeling and Simulation of Heavy Paraffin Dehydrogenation Reactor for Selective Olefin Production in Linear Alkyl Benzene Production Plant  

Microsoft Academic Search

Modeling of a heterogeneous industrial fixed bed reactor for selective dehydrogenation of heavy paraffin with Pt-Sn- Al2O3 catalyst has been the subject of current study. By applying mass balance, momentum balance for appropriate element of reactor and using pressure drop, rate and deactivation equations, a detailed model of the reactor has been obtained. Mass balance equations have been written for

G. Zahedi; H. Yaghoobi

2008-01-01

271

Dynamic modeling and simulation of heavy paraffin dehydrogenation reactor for selective olefin production in linear alkyl benzene production plant  

Microsoft Academic Search

Modeling of a heterogeneous industrial fixed bed reactor for selective dehydrogenation of heavy paraffin with PtSnAl2O3 catalyst has been the subject of current study. Using mass balance, momentum balance for appropriate element of reactor and applying pressure drop, rate and deactivation equations, a detailed model of the reactor has been obtained. Mass balance equations have been used for five different

G. Zahedi; H. Yaqubi; M. Ba-Shammakh

2009-01-01

272

The Use of Microporous Divinyl Benzene Copolymer for Yeast Cell Immobilization and Ethanol Production in Packed-Bed Reactor  

Microsoft Academic Search

Microporous divinyl benzene copolymer (MDBP) was used for the first time as immobilization material for Saccharomyces cerevisiae ATCC 26602 cells in a bed reactor and ethanol production from glucose was studied as a model system. A very homogenous thick\\u000a layer of yeast cells were seen from the scanning electron micrographs on the outer walls of biopolymer. The dried weight of

P?nar Karagz; Elif Erhan; Blent Keskinler; Melek zkan

2009-01-01

273

Use of two different carriers in a packed bed reactor for endopolygalacturonase production by a yeast strain  

Microsoft Academic Search

A packed bed reactor (PBR) design was tested for the purpose of continuous pectinase production with yeasts, as a possible alternative to the traditional batch process using fungal cultures. Two different carriers a porous glass (Siran) and a cellulosic carrier obtained from spent grains (barley) were used to immobilize Kluyveromyces marxianus CCT 3172, a yeast strain secreting endopolygalacturonase.

Catarina Almeida; Tom Brnyik; Pedro Moradas-Ferreira; Jos Teixeira

2005-01-01

274

Processing Tritiated Water at the Savannah River Site: A ProductionScale Demonstration of a Palladium Membrane Reactor  

Microsoft Academic Search

The Palladium Membrane Reactor (PMR) process was installed in the Tritium Facilities at the Savannah River Site to perform a production-scale demonstration for the recovery of tritium from tritiated water adsorbed on molecular sieve (zeolite). Unlike the current recovery process that utilizes magnesium, the PMR offers a means to process tritiated water in a more cost effective and environmentally friendly

Sessions; Kevin L

2005-01-01

275

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

National Technical Information Service (NTIS)

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-imm...

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

1997-01-01

276

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

277

Enhanced production of recombinant aspartase of Aeromonas media NFB-5 in a stirred tank reactor.  

PubMed

Aspartase gene (aspA) from Aeromonas media NFB-5 was cloned and expressed in Escherichia coli BL21 using pET21b(+) expression vector. Maximum production of aspartase was obtained at shake-flask after 5 h of IPTG (1.5 mM) induction at 37C and by supplementing the media with KH2PO4 (0.3%, w/v) and K2HPO4 (0.3%, w/v). Further production was investigated at a laboratory scale stirred tank reactor using response surface methodology (RSM). Agitation (130-270 rpm), aeration (0.30-1.70 vvm) and IPTG induction time (3-7 h) was optimized. Optimal levels of agitation (250 rpm), aeration (1.25 vvm) and induction time (6h) were determined by statistical analysis of the experimental data. More than 7-fold increase in recombinant aspartase (1234 U/g wet weight) was observed than the parent strain (172 U/g wet wt). Homogenized immobilized permeabilized recombinant cells (566 mg/g wet cells) produced more L-aspartic acid as compared to permeabilized recombinant free cells (154 mg/g wet cells). PMID:23219690

Singh, Ram Sarup; Yadav, Mukesh

2013-10-01

278

Reduction of excess sludge production in sequencing batch reactor through incorporation of chlorine dioxide oxidation.  

PubMed

In this study, chlorine dioxide (ClO(2)) instead of chlorine (Cl(2)) was proposed to minimize the formation of chlorine-based by-products and was incorporated into a sequencing batch reactor (SBR) for excess sludge reduction. The results showed that the sludge disintegrability of ClO(2) was excellent. The waste activated sludge at an initial concentration of 15 g MLSS/L was rapidly reduced by 36% using ClO(2) doses of 10mg ClO(2)/g dry sludge which was much lower than that obtained using Cl(2) based on similar sludge reduction efficiency. Maximum sludge disintegration was achieved at 10mg ClO(2)/g dry sludge for 40 min. ClO(2) oxidation can be successfully incorporated into a SBR for excess sludge reduction without significantly harming the bioreactor performance. The incorporation of ClO(2) oxidation resulted in a 58% reduction in excess sludge production, and the quality of the effluent was not significantly affected. PMID:21620565

Wang, Guanghua; Sui, Jun; Shen, Huishan; Liang, Shukun; He, Xiangming; Zhang, Minju; Xie, Yizhong; Li, Lingyun; Hu, Yongyou

2011-08-15

279

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

280

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

NASA Astrophysics Data System (ADS)

The idea of coupling renewable energy production and agricultural waste management inspired this thesis. The production of an important future fuel---hydrogen gas---from high strength waste stream-liquid swine manure---using anaerobic treatment processes makes the most sustainable sense for both wastewater utilization and energy generation. The objectives of this thesis were to develop a fermentation process for converting liquid swine manure to hydrogen and to maximize hydrogen productivity. Anaerobic sequencing batch reactor (ASBR) systems were constructed to carry out this fermentation process, and seed sludge obtained from a dairy manure anaerobic digester and pretreated by nutrient acclimation, heat and pH treatment was used as inoculum. High system stability was indicated by a short startup period of 12 days followed by stable hydrogen production, and successful sludge granulation occurred within 23 days of startup at a hydraulic retention time (HRT) of 24 hours. Operation at a progressively decreasing HRT from 24 to 8h gave rise to an increasing biogas production rate from 15.2-34.4L/d, while good linear relationships were observed between both total biogas and hydrogen production rates correlated to HRT, with R2 values of 0.993 and 0.997, respectively. The maximum hydrogen yield of 1.63 mol-H 2/mol-hexose-feed occurred at HRT of 16h, while the HRT of 12h was highly suggested to achieve both high production rate and efficient yield. Hexose utilization efficiencies over 98%, considerable hydrogen production rate up to 14.3 L/d and hydrogen percentage of off-gas up to 43% (i.e., a CO 2/H2 ratio of 1.2) with the absence of CH4 production throughout the whole course of experiment at a pH of 5.0 strongly validated the feasibility of the fermentative H2 production from liquid swine manure using an ASBR system. Ethanol as well as acetic, butyric and valeric acids were produced in the system accompanying the hydrogen production, with acetic acid being the dominant one, which contributed to 56-58% of the total soluble metabolite production, indicative of an acetic acid fermentation system, and acetate-to-butyrate ratio was found to be closely related to hydrogen yield. pH level influenced every aspect of the ASBR performance for hydrogen production. ASBR operation at five pHs ranging from 4.4 to 5.6 (4.4, 4.7, 5.0, 5.3, 5.6) showed distinct dynamic profiles of both biogas production and the changes of H2 and CH4 percentage in the biogas during a running period of 22 days. The H2 content in biogas, H 2 production rate and H2 yield were all pH-dependent, in the range of 5.1-36.9 %, 0.71-8.97 L/d and 0.12-1.50 mol-H2/mol-glucose, respectively, and maximum values for all three responses were simultaneously achieved at pH 5.0. Methanogens appeared to be significantly activated at pH of 5.3 or higher since significant CH4 evolution and concurrent reduction in H2 production was observed at pH 5.3 and 5.6. Acetate, propionate, butyrate, valerate, and ethanol were main aqueous products in all pH tests and their distribution was influenced by pH. Analysis of kinetic models developed from modified Gompertz equations for batch experiments showed that pH had a profound effect on all kinetic parameters for hydrogen production including hydrogen potential, maximum hydrogen production rate and the length of the lag phase, as well as the maximum substrate utilization rate. The low pH of 4.4 gave the highest hydrogen production potential but with the lowest hydrogen production rate. A contrast experiment was conducted with an initial pH of 5.3 but not controlled, came up with a rapid pH decline, leading to a low hexose degradation efficiency of 33.2% and a significantly suppressed H2 production, indicating the importance of pH control and the effect of pH on H2 production and substrate consumption. pH 5.0 was verified as the optimal for the proposed fermentation system by kinetic models. An extremely linear relationship (R2= 0.993) between the maximum H2 production rate and the maximum hexose degradation rate suggested that the pH inhibitio

Wu, Xiao

281

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

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 processing canyons.

Bergren, C

2009-01-16

282

Dynamic simulation of a tubular reactor for the production of low-density polyethylene using adaptive method of lines  

NASA Astrophysics Data System (ADS)

The dynamic mathematical model of a tubular reactor for the production of low-density polyethylene (LDPE) is introduced and simulation studies of a LDPE plant are presented. The plant consists of the tubular reactor, compressors, heat exchangers and material recycles. The overall model formulation comprises differential, partial differential and algebraic equations. This model formulation is transformed into a DAE system using an adaptive method of lines approach, where the grid points may change their position but their number remains constant. With this technique a solution on a standard PC is possible.

Hafele, M.; Kienle, A.; Boll, M.; Schmidt, C.-U.; Schwibach, M.

2005-11-01

283

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

PubMed

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

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

2014-08-20

284

Improvement of productivity of yeast cell with a novel airlift loop reactor  

Microsoft Academic Search

Two different strains of bakers yeast are cultivated using a fed-batch process with a novel airlift loop reactor. The reactor\\u000a can be operated not only under steadystate conditions as the traditional airlift loop reactor, but also under forced periodically\\u000a operational conditions in which the direction of liquid circulating flow is alternatively changed. Compared with the traditional\\u000a steady-state operation, both the

Dehua Liu; Shian Huamg; Ming Li; Yan Sun; Tianzhong Liu; Fan Ouyang; George T. Tsao

1996-01-01

285

Application of a triga research reactor as the neutron source for a production neutron radiography facility  

Microsoft Academic Search

GA Technologies Inc. (GA) has developed a Stationary Neutron Radiography System (SNRS) using a 250-1000 kW TRIGA reactor as the neutron source. The partially below ground reactor will be equipped with four vertical beam tubes originating in the reactor graphite reflector and installed tangential to the core to provide a strong current of thermal neutrons with minimum gamma-ray contamination. The

Chesworth

1988-01-01

286

Long-lived activation products in TRIGA Mark II research reactor concrete shield: calculation and experiment  

Microsoft Academic Search

In this paper, a process of long-lived activity determination in research reactor concrete shielding is presented. The described process is a combination of experiment and calculations. Samples of original heavy reactor concrete containing mineral barite were irradiated inside the reactor shielding to measure its long-lived induced radioactivity. The most active long-lived (? emitting) radioactive nuclides in the concrete were found

Toma agar; Matja Boi?; Matja Ravnik

2004-01-01

287

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

SciTech Connect

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

Sun, M.Y.; Bienkowski, P.R.; Davison, B.H. [Oak Ridge National Lab., TN (United States)]|[Univ. of Tennessee, Knoxville, TN (United States); Spurrier, M.A.; Webb, O.F. [Univ. of Tennessee, Knoxville, TN (United States)

1996-07-01

288

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

289

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

290

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

291

First production of ultracold neutrons with a solid deuterium source at the pulsed reactor TRIGA Mainz?  

NASA Astrophysics Data System (ADS)

The production rates of ultracold neutrons (UCN) with a solid deuterium converter have been measured at the pulsed reactor TRIGA Mainz. Exposed to a thermal neutron fluence of ensuremath 1\\cdot 10^{13} ncm^-2pulse^-1, the number of detected very cold and ultracold neutrons ranges up to 200 000 at 7mol of solid deuterium (sD2) in combination with a pre-moderator (mesitylene). About 50% of the measured neutrons can be assigned to UCN with energies E of ensuremath V_F(sD_2)? E ? V_F(guide) where V F( sD 2) = 105 neV and V F( guide) = 190 neV are the Fermi potentials of the sD2 converter and our stainless steel neutron guides, respectively. Thermal cycling of solid deuterium, which was frozen out from the gas phase, considerably improved the UCN yield, in particular at higher amounts of sD2.

Frei, A.; Sobolev, Yu.; Altarev, I.; Eberhardt, K.; Gschrey, A.; Gutsmiedl, E.; Hackl, R.; Hampel, G.; Hartmann, F. J.; Heil, W.; Kratz, J. V.; Lauer, Th.; Li?on Aguilar, A.; Mller, A. R.; Paul, S.; Pokotilovski, Yu.; Schmid, W.; Tassini, L.; Tortorella, D.; Trautmann, N.; Trinks, U.; Wiehl, N.

2007-11-01

292

Vapor transport of fission products in postulated severe light water reactor accidents  

SciTech Connect

A methodology based on chemical thermodynamics has been developed to treat the transport of volatile fission products (FPs) through the core and the primary system. The FPs considered are cesium, iodine, tellurium, strontium, and ruthenium, which may pose the major biohazard in postulated severe accidents in light water reactors. The vapor transport of FPs depends on the volatilities of the chemical compounds that are formed in the carrier gas environment in which the FPs are released and transported. Chemically stable forms were evaluated by minimizing the total free energies of the FP/ fuel/gas environment systems. Many gaseous species for each FP were considered and their partial pressures calculated over a range of temperatures (600 to 3000K), the carrier gas environments (total pressure and ratio of H/sub 2//H/sub 2/O), and the total amount of FPs in the system. It was found that the major dependence of the concentration of the FPs was on the gas temperature, and a model was developed to predict the source of volatile FPs. The model showed that the FPs leaving the core region would condense in the cooler regions of the upper plenum and/or the primary system either on the cold surfaces or be transported further as aerosols.

Cubicciotti, D.; Sehgal, B.R.

1984-05-01

293

Production of 37Ar in The University of Texas TRIGA reactor facility  

SciTech Connect

The detection of {sup 37}Ar is important for on-site inspections for the Comprehensive Nuclear-Test-Ban Treaty monitoring. In an underground nuclear explosion this radionuclide is produced by {sup 40}Ca(n,{alpha}){sup 37}Ar reaction in surrounding soil and rock. With a half-life of 35 days, {sup 37}Ar provides a signal useful for confirming the location of an underground nuclear event. An ultra-low-background proportional counter developed by Pacific Northwest National Laboratory is used to detect {sup 37}Ar, which decays via electron capture. The irradiation of Ar gas at natural enrichment in the 3L facility within the Mark II TRIGA reactor facility at The University of Texas at Austin provides a source of {sup 37}Ar for the calibration of the detector. The {sup 41}Ar activity is measured by the gamma activity using an HPGe detector after the sample is removed from the core. Using the {sup 41}Ar/{sup 37}Ar production ratio and the {sup 41}Ar activity, the amount of {sup 37}Ar created is calculated. The {sup 41}Ar decays quickly (half-life of 109.34 minutes) leaving a radioactive sample of high purity {sup 37}Ar and only trace levels of {sup 39}Ar.

Egnatuk, Christine M.; Lowrey, Justin; Biegalski, S.; Bowyer, Ted W.; Haas, Derek A.; Orrell, John L.; Woods, Vincent T.; Keillor, Martin E.

2011-06-19

294

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

PubMed

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

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

2013-10-01

295

A scoping study of fission product transport from failed fuel during N Reactor postulated accidents  

SciTech Connect

This report presents a scoping study of cesium, iodine, and tellurium behavior during a cold leg manifold break in the N Reactor. More detail about fission product behavior than has previously been available is provided and key parameters that control this behavior are identified. The LACE LA1 test and evidence from the Power Burst Facility Severe Fuel Damage tests are used to test the key model applied to determine aerosol behavior. Recommendations for future analysis are also provided. The primary result is that most of the cesium, iodine, and tellurium remains in the molten uranium fuel. Only 0.0035 of the total inventory is calculated to be released. Condensation of the most of the species of cesium and iodine that are released is calculated, with 0.998 of the released cesium and iodine condensing in the spacers and upstream end of the connector tubes. Most of the tellurium that is released condenses, but the chemical reaction of tellurium vapor with surfaces is also a major factor in the behavior of this element.

Hagrman, D.L.

1988-01-01

296

Nutrient removal and biomass production in an outdoor pilot-scale phototrophic biofilm reactor for effluent polishing.  

PubMed

An innovative pilot-scale phototrophic biofilm reactor was evaluated over a 5-month period to determine its capacity to remove nitrogen and phosphorus from Dutch municipal wastewater effluents. The areal biomass production rate ranged between 2.7 and 4.5 g dry weight/m(2)/day. The areal nitrogen and phosphorus removal rates averaged 0.13 g N/m(2)/day and 0.023 g P/m(2)/day, which are low compared to removal rates achieved in laboratory biofilm reactors. Nutrient removal increased during the day, decreased with decreasing light intensity and no removal occurred during the night. Additional carbon dioxide supply was not requisite as the wastewater was comprised of enough inorganic carbon to sustain microalgal growth. The study was not conclusive for the limiting factor that caused the low nutrient removal rate, possibly the process was limited by light and temperature, in combination with pH increases above pH 9 during the daytime. This pilot-scale study demonstrated that the proposed phototrophic biofilm reactor is not a viable post-treatment of municipal wastewater effluents under Dutch climate conditions. However, the reactor performance may be improved when controlling the pH and the temperatures in the morning. With these adaptations, a phototrophic biofilm reactor could be feasible at lower latitudes with higher irradiance levels. PMID:24081706

Boelee, N C; Janssen, M; Temmink, H; Shrestha, R; Buisman, C J N; Wijffels, R H

2014-01-01

297

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

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

298

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

299

Weapon-Grade Plutonium Production Potential in the Indian Prototype Fast Breeder Reactor  

Microsoft Academic Search

India is building a 500 MWe Prototype Fast Breeder Reactor, which is scheduled to be operational by 2010. India has refused to accept international safeguards on this facility, raising concerns that the plutonium produced in its uranium blankets might be used to make nuclear weapons. Based on neutronics calculations for a detailed three-dimensional model of the reactor, we estimate that

Alexander Glaser; M. V. Ramana

2007-01-01

300

Potential for Large-Diameter NTD Silicon Production in the Advanced Test Reactor.  

National Technical Information Service (NTIS)

The Advanced Test Reactor (ATR) is a 250-MW(t) flux-trap reactor located at the Idaho National Engineering Laboratory (INEL). Within the reflector are four 124-mm-diameter I-holes, which are available for silicon irradiation. Two large irradiation volumes...

J. S. Herring R. E. Korenke

1984-01-01

301

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

Microsoft Academic Search

In a molten salt reactor (MSR), the fuel is dissolved in a fluoride salt coolant. The technology was partly developed in the 1950's and 1960's. With changing goals for advanced reactors and new technologies, there is currently a renewed interest in MSRs. The new technologies include (1) Brayton power cycles (rather than steam cycles) that eliminate many of the historical

Charles W. Forsberg; Charles W

2007-01-01

302

Enhanced production of poly(3-hydroxybutyrate) in a novel airlift reactor with insitu cell retention using Azohydromonas australica.  

PubMed

Economic production of biodegradable plastics is a challenge particularly because of high substrate and energy cost inputs for its production. Research efforts are being directed towards innovations to minimize both of the above costs to economize polyhydroxybutyrate (PHB) production. A novel airlift reactor (ALR) with outer aeration and internal settling was utilized in this investigation. Although it featured no power consumption for agitation, it facilitated increased oxygen transfer rate and better cell retention than stirred tank reactor (STR), thereby resulting in enhanced PHB productivity. ALR with in situ cell retention demonstrated a significant improvement in biomass concentration and biopolymer accumulation. The total PHB production rate, specific biomass, and product yield in the ALR were observed to be 0.84 g/h, 0.43 g/g, and 0.32 g/g, respectively. The studies revealed that the volumetric oxygen mass transfer rate and mixing time for ALR were 0.016 s? and 3.73 s, respectively, at 2.0 vvm as compared with corresponding values of 0.005 s? and 4.95 s, respectively, in STR. This demonstrated that ALR has better oxygen mass transfer and mixing efficiency than STR. Hence, ALR with cell retention would serve as a better bioreactor design for economic biopolymer production than STR, particularly due to its lower cost of operation and simplicity along with its enhanced oxygen and heat transfer rates. PMID:22760668

Gahlawat, Geeta; Sengupta, Bedoshree; Srivastava, Ashok K

2012-09-01

303

A multi-phase, micro-dispersion reactor for the continuous production of methane gas hydrate  

SciTech Connect

A continuous-jet hydrate reactor originally developed to generate a CO2 hydrate stream has been modified to continuously produce CH4 hydrate. The reactor has been tested in the Seafloor Process Simulator (SPS), a 72-L pressure vessel available at Oak Ridge National Laboratory. During experiments, the reactor was submerged in water inside the SPS and received water from the surrounding through a submersible pump and CH4 externally through a gas booster pump. Thermodynamic conditions in the hydrate stability regime were employed in the experiments. The reactor produced a continuous stream of CH4 hydrate, and based on pressure values and amount of gas injected, the conversion of gas to hydrate was estimated. A conversion of up to 70% was achieved using this reactor.

Taboada Serrano, Patricia L [ORNL; Ulrich, Shannon M [ORNL; Szymcek, Phillip [ORNL; McCallum, Scott [Oak Ridge Associated Universities (ORAU); Phelps, Tommy Joe [ORNL; Palumbo, Anthony Vito [ORNL; Tsouris, Costas [ORNL

2009-01-01

304

A model of the control rod housing overflow incident in a Savannah River Production Reactor  

SciTech Connect

On May 25, 1992, K-reactor at the Savannah River Site was being configured for start up when a D20 leak of unknown origin was detected on the top of the reactor. The reactor was immediately shutdown, and reactor start up was put on hold until the cause of the leak was determined and the problem eliminated. The source of the leak was suspected to be overflow of the control rod guide tubes, and on May 27 hydraulic tests in the laboratory confirmed this and identified the cause to be unanticipated secondary circulations in the control rod housings. The modelling effort, that in conjunction with the experimental program, identified a temporary fix that allowed K-reactor to be restarted two weeks after the initial overflow incident is herein described.

Shadday, M.A. Jr.; Flach, G.P.; Steimke, J.L.; Koffman, L.D.; Askew, N.M.

1993-05-01

305

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

306

Structural testing of corrugated asbestos-cement roof panels at the Hanford Facilities, Richland, Washington  

SciTech Connect

This report describes a roof testing program that was carried out at the 105KE/KW Spent Fuel Storage Basins and their surrounding facilities at the Hanford Site in Richland, Washington. The roof panels were constructed in the mid 1950`s of corrugated asbestos-cement (A/C), which showed common signs of aging. Based on the construction specifications, the panels capacity to meet current design standards was questioned. Both laboratory and in-situ load testing of the corrugated A/C panels was conducted. The objective of the complete test program was to determine the structural integrity of the existing A/C roof panels installed in the 105KE and 105KW facilities. The data from these tests indicated that the roofs are capable of resisting the design loads and are considered safe. A second phase test to address the roof resistance to personnel and roof removal/roofing system installation equipment was recommended and is underway.

Moustafa, S.E.; Rodehaver, S.M. [Wiss, Janney, Elstner Associates, Inc., Seattle, WA (United States); Frier, W.A. [Westinghouse Hanford Co., Richland, WA (United States)

1993-10-01

307

Columbia River monitoring: Summary of chemical monitoring along cross sections at Vernita Bridge and Richland  

SciTech Connect

This report presents the results of the chemical monitoring performed by the Surface Environmental Surveillance Project (SESP) along cross sections of the Columbia River established at Vernita Bridge and the Richland Pumphouse. Potential Hanford-origin chemical constituents of interest were selected based on their presence in ground water near the river, past surveillance efforts that have documented their entry into the river, and reviews of special study reports, CERCIA remedial investigation/feasibility study (RI/FS) documentation, RCRA facility investigation/corrective measure (FI/CW) study plans, and preliminary risk assessments. Results presented in this report include volatile organic compounds, metals, and anions. The data were generated as part of the routine Columbia River monitoring program currently conducted as part of the SESP.

Dirkes, R.L.; Patton, G.W.; Tiller, B.L.

1993-05-01

308

Geologic map of the Richland 1:100,000 quadrangle, Washington  

SciTech Connect

This map of the Richland 1:100,000-scale quadrangle, Washington, shows the geology of one of fifteen complete or partial 1:100,000-scale quadrangles that cover the southeast quadrant of Washington. Geologic maps of these quadrangles have been compiled by geologists with the Washington Division of Geology and Earth Resources (DGER) and Washington State University and are the principal data sources for a 1:250,000-scale geologic map of the southeast quadrant of Washington, which is in preparation. Eleven of these quadrangles are being released as DGER open-file reports. The map of the Wenatchee quadrangle has been published by the US Geological Survey, and the Moses Lake, Ritzville quadrangles have already been released.

Reidel, S.P.; Fecht, K.R. [comps.

1993-09-01

309

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

310

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

NASA Astrophysics Data System (ADS)

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

Cubicciotti, Daniel

1985-02-01

311

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

312

Effect of catalyst additives on the production of biofuels from palm oil cracking in a transport riser reactor  

Microsoft Academic Search

Catalytic cracking of crude palm oil (CPO) and used palm oil (UPO) were studied in a transport riser reactor for the production of biofuels at a reaction temperature of 450C, with residence time of 20s and catalyst-to-oil ratio (CTO) of 5gg?1. The effect of HZSM-5 (differrent Si\\/Al ratios), beta zeolite, SBA-15 and AlSBA-15 were studied as physically mixed additives with

Thiam Leng Chew; Subhash Bhatia

2009-01-01

313

Growth and hyoscyamine production of hairy root cultures of Datura stramonium in a modified stirred tank reactor  

Microsoft Academic Search

The growth and hyoscyamine production of transformed roots of Datura stramonium have been examined in a modified 14-1 stirred tank reactor in both batch and continuous fermentations on media containing half or full strength Gamborg's B5 salts and at three different temperatures. Under a range of conditions, roots grown on half strength B5 salts with 3% w\\/v sucrose had a

M. G. Hilton; M. J. C. Rhodes

1990-01-01

314

Simulation and thermodynamic analysis of an integrated process with H 2 membrane CPO reactor for pure H 2 production  

Microsoft Academic Search

A one-dimensional steady-state heterogeneous model has been used to simulate the H2 membrane reactor. The simulation work is the basis for the thermodynamic analysis of the integrated pure H2 production process. The simulation and analysis also provide a quantitative tool for insight into and understanding the process.The simulation and thermodynamic analysis results indicate that increasing the inlet ratio H2O\\/CH4 cannot

Peijun Ji; H. J. van der Kooi; J. de Swaan Arons

2003-01-01

315

Production of Activated Carbon from Jojoba Seed Residue by Chemical Activation Residue Using a Static Bed Reactor  

Microsoft Academic Search

The production of chemically activated carbon from Jojoba seed residue was experimentally investigated using a laboratory-scale static bed reactor. The effects of process variables such as activation time, activation temperature, particle size, chemical reagents (KCl, ZnCl2 and H3PO4) and impregnation ratio on adsorption capacity of activated Jojoba seed residue were studied. The highest iodine number and yield were obtained by

Muhammad Tawalbeh; Mamdouh A. Allawzi; Munther I. Kandah

2005-01-01

316

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

317

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

318

S.C. Road S-33, Trenholm Road From Belt Line to Near Rockbridge Road, Richland County, Columbia, South Carolina.  

National Technical Information Service (NTIS)

Road S-33-Trenholm Road, located in Richland County, Columbia, South Carolina is proposed to be up-graded from two to four lanes from near Belt Line Boulevard to near Rockbridge Road. The proposed 3.3 mile project is an integral part of the Columbia Area ...

1971-01-01

319

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

NASA Technical Reports Server (NTRS)

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

Woerner, L.

1977-01-01

320

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...

321

Non-fossil energy for the production of synthetic fuels from coal. I. Fusion reactor with high temperature steam electrolyzer and gasifier  

Microsoft Academic Search

Fusion reactors could displace a large amount of the coal needed for synthetic fuel production. A unique feature of a fusion reactor is that it can potentially supply high temperature steam in the range of 1000° to 1500°C in a continuous manner. The high temperature steam would be obtained by internal heating of a refractory containing blanket section which would

Steinberg

1978-01-01

322

Non-fossil energy for the production of synthetic fuels from Coal I. Fusion reactor with high temperature steam electrolyzer and gasifier  

Microsoft Academic Search

Fusion reactors could displace a large amount of the coal needed for synthetic fuel production. A unique feature of a fusion reactor is that it can potentially supply high temperature steam in the range of 1000° to 1500°C in a continuous manner. The high temperature steam would be obtained by internal heating of a refractory containing blanket section which would

Steinberg

1980-01-01

323

Physical Description of Fission Product Behavior in Fuels for Advanced Power Reactors.  

National Technical Information Service (NTIS)

The Global Nuclear Energy Partnership (GNEP) is considering a list of reactors and nuclear fuels as part of its chartered initiative. Because many of the candidate materials have not been explored experimentally under the conditions of interest, and in or...

G. Kagana J. Rest

2007-01-01

324

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

Microsoft Academic Search

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

W. E. Cawley; R. P. Omberg

1982-01-01

325

High Velocity Continuous-Flow Reactor for the Production of Solar Grade Silicon. Second Quarterly Report.  

National Technical Information Service (NTIS)

The objective is to determine the feasibility of a high volume-high velocity continuous reduction reactor as an economical means for producing solar grade polycrystalline silicon. Preheated streams of hydrogen and bromosilanes are used as feed to the redu...

L. Woerner

1978-01-01

326

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

DOEpatents

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

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

1982-08-19

327

Fuel Assembly for the Production of Tritium in Light Water Reactors.  

National Technical Information Service (NTIS)

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an...

W. E. Cawley T. J. Trapp

1983-01-01

328

Biogas production from supernatant of hydrothermally treated municipal sludge by upflow anaerobic sludge blanket reactor  

Microsoft Academic Search

The supernatant of hydrothermally treated sludge was treated by an upflow anaerobic sludge blanket (UASB) reactor for a 550-days running test. The hydrothermal parameter was 170C for 60min. An mesophilic 8.6L UASB reactor was seeded with floc sludge. The final organic loading rate (OLR) could reach 18kg COD\\/m3d. At the initial stage running for 189days, the feed supernatant was diluted,

Wei Qiao; Chong Peng; Wei Wang; ZhongZhi Zhang

2011-01-01

329

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

SciTech Connect

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

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

2005-02-13

330

A preliminary report on methods of measuring and reducing Argon41 production by a TRIGA reactor  

Microsoft Academic Search

Methods to accurately determine and techniques to reduce the Argon-41 released from the one-megawatt Geological Survey TRIGA Reactor facility have been developed. Knowledge of the composition of the exhaust-gas effluent is of prime importance to the U.S. Geological Survey in minimizing all radioactive releases to the environment. The counting systems and control measures have enabled the Geological Survey TRIGA Reactor

1972-01-01

331

Removal of total coliforms, thermotolerant coliforms, and helminth eggs in Swine production wastewater treated in anaerobic and aerobic reactors.  

PubMed

The present work evaluated the performance of two treatment systems in reducing indicators of biological contamination in swine production wastewater. System I consisted of two upflow anaerobic sludge blanket (UASB) reactors, with 510 and 209?L in volume, being serially arranged. System II consisted of a UASB reactor, anaerobic filter, trickling filter, and decanter, being also organized in series, with volumes of 300, 190, 250, and 150?L, respectively. Hydraulic retention times (HRT) applied in the first UASB reactors were 40, 30, 20, and 11?h in systems I and II. The average removal efficiencies of total and thermotolerant coliforms in system I were 92.92% to 99.50% and 94.29% to 99.56%, respectively, and increased in system II to 99.45% to 99.91% and 99.52% to 99.93%, respectively. Average removal rates of helminth eggs in system I were 96.44% to 99.11%, reaching 100% as in system II. In reactor sludge, the counts of total and thermotolerant coliforms ranged between 10(5) and 10(9)?MPN (100?mL)(-1), while helminth eggs ranged from 0.86 to 9.27?eggs?g(-1)?TS. PMID:24812560

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

2014-01-01

332

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

PubMed Central

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

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

2014-01-01

333

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

334

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 37C 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.

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

2011-01-01

335

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

336

Citrus peel influences the production of an extracellular naringinase by Staphylococcus xylosus MAK2 in a stirred tank reactor.  

PubMed

Staphylococcus xylosus MAK2, Gram-positive coccus, a nonpathogenic member of the coagulase-negative Staphylococcus family was isolated from soil and used to produce naringinase in a stirred tank reactor. An initial medium at pH 5.5 and a cultivation temperature of 30C was found to be optimal for enzyme production. The addition of Ca(+) caused stimulation of enzyme activity. The effect of various physico-chemical parameters, such as pH, temperature, agitation, and inducer concentration was studied. The enzyme production was enhanced by the addition of citrus peel powder (CPP) in the optimized medium. A twofold increase in naringinase production was achieved using different technological combinations. The process optimization using technological combinations allowed rapid optimization of large number of variables, which significantly improved enzyme production in a 5-l reactor in 34 h. An increase in sugar concentration (15 g?l?) in the fermentation medium further increased naringinase production (8.9 IU?ml?) in the bioreactor. Thus, availability of naringinase renders it attractive for potential biotechnological applications in citrus processing industry. PMID:20922381

Puri, Munish; Kaur, Aneet; Barrow, Colin J; Singh, Ram Sarup

2011-02-01

337

Novel Reactor for the Production of Synthesis Gas DOE Award No. DE-FC26-00NT41027. (Report for September 2001 to December 2003).  

National Technical Information Service (NTIS)

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 Praxairs gas mixing technology to provide a novel reactor system. The progr...

2004-01-01

338

Effect of addition of water-soluble polysaccharides on bacterial cellulose production in a 50-L airlift reactor.  

PubMed

Bacterial cellulose (BC) production was carried out in a batch cultivation of Acetobacter xylinum in a 50-L internal loop airlift reactor by addition of water-soluble polysaccharides into the medium. When 0.1% (w/w) agar was added, BC production reached 8.7 g/L compared with 6.3 g/L in the control, and duration of the cultivation period to reach the maximum concentration of BC was almost half of that without addition of polysaccharides. During cultivation, BC was formed into pellets whose size was smaller when the productivity of BC was higher, indicating that increase in the relative viscosity by addition of polysaccharides hindered formation of large clumps of BC and increase in the volumetric oxygen transfer coefficient at high flow rate led to increase in BC productivity. PMID:11485444

Chao, Y; Mitarai, M; Sugano, Y; Shoda, M

2001-01-01

339

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

SciTech Connect

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

Casoli, P.; Authier, N. [CEA, Centre de Valduc, 21120 Is-sur-Tille (France); Laurec, J.; Bauge, E.; Granier, T. [CEA, Centre DIF, 91297 Arpajon (France)

2011-07-01

340

Fission product release and fuel behavior of irradiated light water reactor fuel under severe accident conditions. The ACRR ST1 Experiment  

Microsoft Academic Search

The annular Core Research Reactor (ACRR) Source Term (ST) Experiment program was designed to obtain time-resolved data on the release of fission products from irradiated fuels under well-controlled light water reactor severe accident conditions. The ST-1 Experiment was the first of two experiments designed to investigate fission product release. ST-1 was conducted in a highly reducing environment at a system

M. D. Allen; H. W. Stockman; K. O. Reil; J. W. Fisk

1991-01-01

341

Production of hydrogen and syngas via gasification of the corn and wheat dry distiller grains (DDGS) in a fixed-bed micro reactor  

Microsoft Academic Search

Production of hydrogen and syngas via gasification of the corn and wheat dry distiller grains (DDGS) with oxygen in a continuous downflow fixed bed micro reactor are studied in this paper. A series of experiments have been performed to investigate the effects of reaction time (1545min), reactor temperature (700900C) and oxygen to nitrogen ratio (0.080.2 vol.\\/vol.) on product gas composition,

Ahmad Tavasoli; Masoumeh G. Ahangari; Chirayu Soni; Ajay K. Dalai

2009-01-01

342

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

PubMed

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

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

2014-10-01

343

Long-lived activation products in TRIGA Mark II research reactor concrete shield: calculation and experiment  

NASA Astrophysics Data System (ADS)

In this paper, a process of long-lived activity determination in research reactor concrete shielding is presented. The described process is a combination of experiment and calculations. Samples of original heavy reactor concrete containing mineral barite were irradiated inside the reactor shielding to measure its long-lived induced radioactivity. The most active long-lived (? emitting) radioactive nuclides in the concrete were found to be 133Ba, 60Co and 152Eu. Neutron flux, activation rates and concrete activity were calculated for actual shield geometry for different irradiation and cooling times using TORT and ORIGEN codes. Experimental results of flux and activity measurements showed good agreement with the results of calculations. Volume of activated concrete waste after reactor decommissioning was estimated for particular case of Joef Stefan Institute TRIGA reactor. It was observed that the clearance levels of some important long-lived isotopes typical for barite concrete (e.g. 133Ba, 41Ca) are not included in the IAEA and EU basic safety standards.

agar, Toma; Boi?, Matja; Ravnik, Matja

2004-12-01

344

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 6.3g 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

Fernndez, Camino; Carracedo, Begoa; Martnez, Elia Judith; Gmez, Xiomar; Morn, Antonio

2014-01-01

345

Design and operating characteristics of a metalorganic vapor phase epitaxy production scale, vertical, high speed, rotating disk reactor  

NASA Astrophysics Data System (ADS)

The optoelectronic and digital compound semiconductor electronics industry is a critical area of development for the 90's and into the next century. Optoelectronic devices are used in all aspects of communications (lasers and detectors) and displays (LEDs). High speed electronic devices find applications in wireless communications, microwave systems, and advanced computers. As production levels of these devices increase, so too does the need for economical and high yield production equipment. Production features must emphasize repeatability, improved safety, environmental compatability, waste reduction, reliability (maximum MTBF), serviceability (minimum MTTR), flexible manufacturing, integrated manufacturing, and economics. In this paper, we report on the development and characteristics of such a large area MOVPE production Rotating Disk Reactor system (300 mm diameter deposition platform). This new reactor has been used to produce multiple 4 inch GaAs/AlAs Bragg reflectors with <1.0% variation in peak reflectivity wavelength and to simultaneously demonstrate multiple 2 inch InGaP films with better than 1.5 nm photoluminescence wavelength uniformity.

Tompa, G. S.; Zawadzki, P. A.; Moy, K.; McKee, M.; Thompson, A. G.; Gurary, A. I.; Wolak, E.; Esherick, P.; Breiland, W. G.; Evans, G. H.; Bulitka, N.; Hennessy, J.; Moore, C. J. L.

1994-12-01

346

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

347

Application of a triga research reactor as the neutron source for a production neutron radiography facility  

SciTech Connect

GA Technologies Inc. (GA) has developed a Stationary Neutron Radiography System (SNRS) using a 250-1000 kW TRIGA reactor as the neutron source. The partially below ground reactor will be equipped with four vertical beam tubes originating in the reactor graphite reflector and installed tangential to the core to provide a strong current of thermal neutrons with minimum gamma-ray contamination. The vertical beam tubes interface with rugged component positioning systems designed to handle intact F-11 aircraft wings, partial A-10 aircraft wings, pyrotechnics, and other honeycomb aircraft structures. The SNRS will be equipped with real-time, near-real-time, and film-radiographic imaging systems to provide a broad spectrum of capability for detection of corrosion or entrained moisture in large aircraft panels.

Chesworth, R.H.

1988-01-01

348

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

349

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

350

Catalytic steam gasification of pig compost for hydrogen-rich gas production in a fixed bed reactor.  

PubMed

The catalytic steam gasification of pig compost (PC) for hydrogen-rich gas production was experimentally investigated in a fixed bed reactor using the developed NiO on modified dolomite (NiO/MD) catalyst. A series of experiments have been performed to explore the effects of catalyst, catalytic temperature, steam to PC ratio and PC particle size on the gas quality and yield. The results indicate that the NiO/MD catalyst could significantly eliminate the tar in the gas production and increase the hydrogen yield, and the catalyst lives a long lifetime in the PC steam gasification. Moreover, the higher catalytic temperature and smaller PC particle size can contribute to more hydrogen production and gas yield. Meanwhile, the optimal ratio of steam to PC (S/P) is found to be 1.24. PMID:23422306

Wang, Jingbo; Xiao, Bo; Liu, Shiming; Hu, Zhiquan; He, Piwen; Guo, Dabin; Hu, Mian; Qi, Fangjie; Luo, Siyi

2013-04-01

351

Survey of Corrosion Product Generation, Transport, and Deposition in Light Water Nuclear Reactors. Final Report.  

National Technical Information Service (NTIS)

Areas discussed include metal and oxide solubilities, particle movement, corrosion mechanisms, corrosion kinetics, corrosion product release from corroding surfaces and from deposits, corrosion product transport, corrosion product deposition, mechanisms, ...

R. B. Diegle W. E. Berry

1979-01-01

352

Continuous production of L- tert -leucine in series of two enzyme membrane reactors  

Microsoft Academic Search

The L-tert-leucine synthesis was performed continuously in series of two enzyme-membrane reactors by reductive amination of trimethylpyruvate with leucine dehydrogenase. The necessary native cofactor NADH is regenerated with the aid of a second enzyme, formate dehydrogenase.

U. Kragl; D. Vasic-Racki; C. Wandrey

1996-01-01

353

Gasification of refuse derived fuel in a fixed bed reactor for syngas production  

Microsoft Academic Search

Steam gasification of two different refuse derived fuels (RDFs), differing slightly in composition as well as thermal stability, was carried out in a fixed-bed reactor at atmospheric pressure. The proximate and ultimate analyses reveal that carbon and hydrogen are the major components in RDFs. The thermal analysis indicates the presence of cellulose and plastic based materials in RDFs. H2 and

Ajay K. Dalai; Nishant Batta; I. Eswaramoorthi; Greg J. Schoenau

2009-01-01

354

Comparison of mesophilic and thermophilic upflow anaerobic sludge blanket reactors treating instant coffee production wastewater  

Microsoft Academic Search

Stable anaerobic digestion of settled instant coffee wastewater was achieved for over 100 days in mesophilic (35C) and termophilic (55C) UASB reactors. Thermophilic upflow anaerobic sludge blankets (UASBs) were seeded with mesophilic granules and converted to thermophilic operation by raising the temperature to 55C in one step. Successful thermophilic operation was achieved within 28 days. Both mesophilic and thermophilic UASBs

Richard M. Dinsdale; Freda R. Hawkes; Dennis L. Hawkes

1997-01-01

355

Verification of Fission Product Release Model from High Temperature Engineering Test Reactor Fuel  

Microsoft Academic Search

A fuel assembly of the High Temperature Engineering Test Reactor (HTTR) is composed of fuel rods and a hexagonal graphite block. A fuel rod is composed of the fuel compacts and a graphite sleeve. The coated fuel particles are incorporated into a graphite matrix to form a fuel compact. The fuel consists of microspheres of low-enriched U02 with a TRISO

Kazuhiro SAWA; Shusaku SHIOZAWA; Kousaku FUKUDA; Yoshinori ICHIHASHI

1992-01-01

356

Overall control strategy of a coupled reactor\\/columns process for the production of ethyl acrylate  

Microsoft Academic Search

Ethyl acrylate (EA) is widely used in industry as a precursor for varnishes, adhesive, and finishes of papers and textiles. This important ester can be produced directly from ethanol (EtOH) and acrylic acid (AA) via esterification reaction with the presence of sulphuric acid as homogeneous catalyst. The proposed design flowsheet of this process includes a CSTR reactor coupled with a

I-Lung Chien; Kay Chen; Chien-Lin Kuo

2008-01-01

357

Antibiotics production in a fluidized bed reactor utilizing a transverse magnetic field  

Microsoft Academic Search

A mathematical model is developed to describe the performance of a three-phase fluidized bed reactor utilizing a transverse magnetic field. The model is based on the axially dispersed plug flow model for the bulk of liquid phase and on the Michaelis-Menten kinetics. The model equations are solved by the explicit finite difference method from transient to steady state conditions. The

Z. Al-Qodah

2000-01-01

358

HYBRID SULFUR CYCLE FLOWSHEETS FOR HYDROGEN PRODUCTION USING HIGH-TEMPERATURE GAS-COOLED REACTORS  

SciTech Connect

Two hybrid sulfur (HyS) cycle process flowsheets intended for use with high-temperature gas-cooled reactors (HTGRs) are presented. The flowsheets were developed for the Next Generation Nuclear Plant (NGNP) program, and couple a proton exchange membrane (PEM) electrolyzer for the SO2-depolarized electrolysis step with a silicon carbide bayonet reactor for the high-temperature decomposition step. One presumes an HTGR reactor outlet temperature (ROT) of 950 C, the other 750 C. Performance was improved (over earlier flowsheets) by assuming that use of a more acid-tolerant PEM, like acid-doped poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI), instead of Nafion{reg_sign}, would allow higher anolyte acid concentrations. Lower ROT was accommodated by adding a direct contact exchange/quench column upstream from the bayonet reactor and dropping the decomposition pressure. Aspen Plus was used to develop material and energy balances. A net thermal efficiency of 44.0% to 47.6%, higher heating value basis is projected for the 950 C case, dropping to 39.9% for the 750 C case.

Gorensek, M.

2011-07-06

359

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

Microsoft Academic Search

In recent years there has been an unstable supply of the critical diagnostic medical isotope 99Tc. Several concepts and designs have been proposed to produce 99Mo the parent nuclide of 99Tc, at a commercial scale sufficient to stabilize the world supply. This work lays out a testing and experiment plan for a proposed 2 MW open pool reactor fueled by

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

2010-01-01

360

Characterization of Argon-41 Production at N Reactor Hanford Reservation, Washington.  

National Technical Information Service (NTIS)

As a result of normal N Reactor operation, approximately 50,000 curies of exp 41 Ar are released to the atmosphere at Hanford each year. Although the total population whole-body dose of 1.1 man-rem/year due to these exp 41 Ar emissions is very small compa...

A. L. Cucchiara

1975-01-01

361

IMPROVEMENTS IN OR RELATING TO THE PRODUCTION OF MECHANICAL POWER FROM THERMONUCLEAR REACTORS  

Microsoft Academic Search

A power removal system for thermonuclear reactors is described. An ; electric motor brings a single-phase alternator, a flywheel, and a three-phase ; alternator, all on the same shaft, up to speed. The three-phase alternator is ; connected through a switch to the primary of a transformer, the secondary of ; which is a ring-discharge apparatus wherein thermonuclear reactions occur.

Carruthers

1960-01-01

362

IMPROVEMENTS IN OR RELATING TO PRODUCTION OF ELECTRICAL POWER FROM THERMONUCLEAR REACTORS  

Microsoft Academic Search

A method is presented for producing power from a toroidal thermonuclear ; reactor. A condenser discharges periodically through the gas-filled torus which ; forms the secondary of a transformer. A second condenser discharges through the ; primary of the transformer with alternating polarity. Thus the primary current ; in successive discharges through a switching system always moves in the same

Carruthers

1960-01-01

363

Sludge stabilization at the Plutonium Finishing Plant, Hanford Site, Richland, Washington  

SciTech Connect

This Environmental Assessment evaluates the proposed action to operate two laboratory-size muffle furnaces in glovebox HC-21C, located in the Plutonium Finishing Plant (PFP), Hanford Site, Richland, Washington. The muffle furnaces would be used to stabilize chemically reactive sludges that contain approximately 25 kilograms (55 pounds) of plutonium by heating to approximately 500 to 1000{degrees}C (900 to 1800{degrees}F). The resulting stable powder, mostly plutonium oxide with impurities, would be stored in the PFP vaults. The presence of chemically reactive plutonium-bearing sludges in the process gloveboxes poses a risk to workers from radiation exposure and limits the availability of storage space for future plant cleanup. Therefore, there is a need to stabilize the material into a form suitable for long-term storage. This proposed action would be an interim action, which would take place prior to completion of an Environmental Impact Statement for the PFP which would evaluate stabilization of all plutonium-bearing materials and cleanout of the facility. However, only 10 percent of the total quantity of plutonium in reactive materials is in the sludges, so this action will not limit the choice of reasonable alternatives or prejudice the Record of Decision of the Plutonium Finishing Plant Environmental Impact Statement.

Not Available

1994-10-01

364

Effect of catalyst additives on the production of biofuels from palm oil cracking in a transport riser reactor.  

PubMed

Catalytic cracking of crude palm oil (CPO) and used palm oil (UPO) were studied in a transport riser reactor for the production of biofuels at a reaction temperature of 450 degrees C, with residence time of 20s and catalyst-to-oil ratio (CTO) of 5 gg(-1). The effect of HZSM-5 (different Si/Al ratios), beta zeolite, SBA-15 and AlSBA-15 were studied as physically mixed additives with cracking catalyst Rare earth-Y (REY). REY catalyst alone gave 75.8 wt% conversion with 34.5 wt% of gasoline fraction yield using CPO, whereas with UPO, the conversion was 70.9 wt% with gasoline fraction yield of 33.0 wt%. HZSM-5, beta zeolite, SBA-15 and AlSBA-15 as additives with REY increased the conversion and the yield of organic liquid product. The transport riser reactor can be used for the continuous production of biofuels from cracking of CPO and UPO over REY catalyst. PMID:19138514

Chew, Thiam Leng; Bhatia, Subhash

2009-05-01

365

Experimental Evaluation of Secondary Hydrate Formation during Methane Production in a Reactor Containing Hydrate-Bearing Porous Media  

NASA Astrophysics Data System (ADS)

Numerical simulations on methane hydrate dissociation have shown that during methane production from hydrate reservoirs and laboratory-scale reactors, secondary hydrate formation developed around the production port and partially blocked gas flow coming from dissociating hydrate. It is desirable to validate the hydrate decomposition in a viable scale at conditions promoting secondary hydrate formation in an attempt to understand its potential impact on natural gas production at a reservoir scale. A series of laboratory experiments has been performed to observe the occurrence of secondary hydrate formation in a laboratory- scale, cylindrical pressure vessel. Methane hydrate formed in a reactor filled with wetted sand was exposed to a pressure drop and thermal stimulation to induce hydrate decomposition. An X-ray CT scanner was used to observe changes in density occurring inside a hydrate core during hydrate formation and dissociation. The results will be discussed in regards to the impact of various hydrological properties of hydrate-bearing porous medium including initial hydrate saturation and distribution.

Seol, Y.; Myshakin, E. M.; Zhang, W.; Warzinski, R. P.

2008-12-01

366

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

367

Processing Tritiated Water at the Savannah River Site: A Production-Scale Demonstration of a Palladium Membrane Reactor  

SciTech Connect

The Palladium Membrane Reactor (PMR) process was installed in the Tritium Facilities at the Savannah River Site to perform a production-scale demonstration for the recovery of tritium from tritiated water adsorbed on molecular sieve (zeolite). Unlike the current recovery process that utilizes magnesium, the PMR offers a means to process tritiated water in a more cost effective and environmentally friendly manner. The design and installation of the large-scale PMR process was part of a collaborative effort between the Savannah River Site and Los Alamos National Laboratory.The PMR process operated at the Savannah River Site between May 2001 and April 2003. During the initial phase of operation the PMR processed thirty-four kilograms of tritiated water from the Princeton Plasma Physics Laboratory. The water was processed in fifteen separate batches to yield approximately 34,400 liters (STP) of hydrogen isotopes. Each batch consisted of round-the-clock operations for approximately nine days. In April 2003 the reactor's palladium-silver membrane ruptured resulting in the shutdown of the PMR process. Reactor performance, process performance and operating experiences have been evaluated and documented. A performance comparison between PMR and current magnesium process is also documented.

Sessions, Kevin L. [Westinghouse Savannah River Company (United States)

2005-07-15

368

Influence of organic loading rate on the anaerobic treatment of sugarcane vinasse and biogs production in fluidized bed reactor.  

PubMed

This study evaluated an anaerobic fluidized bed reactor (AFBR) that contained polystyrene particles as a support material for the treatment of vinasse that resulted from the alcoholic fermentation of sugarcane molasses. The AFBR was inoculated with sludge from an upflow anaerobic sludge blanket reactor that treated poultry slaughterhouse wastewater. The AFBR was operated with a hydraulic retention time of 24h at a temperature of 30C with influent vinasse concentrations that ranged from 2273 to 20,073mg COD L(-1). The reactor was subjected to increased organic loading rates (OLR) that ranged from 3.33 to 26.19kg COD m(-3) d(-1), with COD removal efficiencies that ranged from 51% to 70% and maximum removal at an OLR of 13.93 2.18kg COD m(-3) d(-1). The maximum biogas productivity was 5.37m(3) CH4 m(-3) d(-1) for an OLR of 25.32kg COD m(-3) d(-1) (average removal of 51%).. PMID:23947710

Siqueira, Laura M; Damiano, Elisabeth S G; Silva, Edson L

2013-01-01

369

Minimization of sludge production by a side-stream reactor under anoxic conditions in a pilot plant.  

PubMed

This study evaluates the application of an anoxic side-stream reactor in the sludge return line of a conventional activated sludge system for the reduction of biomass production. The oxidation-reduction potential was maintained at -150 mV while the applied sludge loading rate was modified by changing the percentage of return sludge treated in this reactor. The observed yield from the conventional system (0.513 kg VSS kg(-1) COD) was continuously reduced when the portion of return sludge treated was increased. A maximum reduction of 18.3% of the observed yield was obtained treating the whole sludge return line. The sludge age maintained through the experiment. The organic matter removal was not deteriorated, even improved, by the proposed plant modification. Thus, simply applying an anoxic side-stream reactor would decrease the final volume of waste sludge while maintaining the sludge retention time and would, in fact, decrease the economic costs in terms of sludge handling. PMID:23247151

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

2013-02-01

370

ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION  

SciTech Connect

A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

Gorensek, M.; Edwards, T.

2009-06-11

371

Tritium production, management and its impact on safety for a D- sup 3 He fusion reactor  

SciTech Connect

About three percent of the fusion energy produced by a D-{sup 3}He reactor is in the form of neutrons. Those neutrons are generated by D-D and D-T reactions, with the tritium produced by the D-D fusion. The neutrons will react with structural steel, deuterium, {sup 3}He and shielding material to produce tritium. About half of the tritium generated by the D-D reaction will not burn in the plasma and will exit as a part of the plasma exhaust. Thus, there is enough tritium produced in a D-{sup 3}He reactor and careful management will be required. The tritium produced in the shield and plasma can be managed with an acceptable effect on cost and safety. 3 refs., 2 figs., 3 tabs.

Sze, D.K. (Argonne National Lab., IL (United States)); Herring, S. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Sawan, M. (Wisconsin Univ., Madison, WI (United States))

1991-11-01

372

Computational and experimental prediction of dust production in pebble bed reactors, Part II  

SciTech Connect

This paper is the continuation of Part I, which describes the high temperature and high pressure helium environment wear tests of graphitegraphite in frictional contact. In the present work, it has been attempted to simulate a Pebble Bed Reactor core environment as compared to Part I. The experimental apparatus, which is a custom-designed tribometer, is capable of performing wear tests at PBR relevant higher temperatures and pressures under a helium environment. This environment facilitates prediction of wear mass loss of graphite as dust particulates from the pebble bed. The experimental results of high temperature helium environment are used to anticipate the amount of wear mass produced in a pebble bed nuclear reactor.

Mie Hiruta; Gannon Johnson; Maziar Rostamian; Gabriel P. Potirniche; Abderrafi M. Ougouag; Massimo Bertino; Louis Franzel; Akira Tokuhiro

2013-10-01

373

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

374

Fuel assembly for the production of tritium in light water reactors  

DOEpatents

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

Cawley, William E. (Richland, WA); Trapp, Turner J. (Richland, WA)

1985-01-01

375

Fuel assembly for the production of tritium in light water reactors  

DOEpatents

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

Cawley, W.E.; Trapp, T.J.

1983-06-10

376

Phototrophic bacterial production of oleic acid in an illuminated upflow anaerobic sludge blanket reactor  

Microsoft Academic Search

Phototrophic bacterial cells in the effluent from a lighted upflow anaerobic sludge blanket reactor supplied with a medium containing 142mg S (as SO42-)l-1 accumulated a 6.8% w\\/w oleic acid content in cells and 19mg cell-bound oleic acidl-1 in the effluent. Pure cultures of Rhodopseudomonas palustris and Blastochloris sulfoviridis isolated from the effluent also accumulated 5.1 and 6.4% w\\/w oleic acid

Shigeki Sawayama; Seiichi Inoue; Kenichiro Tsukahara; Tatsuo Yagishita

2001-01-01

377

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

Microsoft Academic Search

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

Charles M Barnes

2008-01-01

378

Production of pyrolytic liquids from industrial sewage sludges in an induction-heating reactor  

Microsoft Academic Search

With the application of induction-heating, the pyrolytic experiments have been carried out for three sewage sludges from the food processing factories in an externally heated fixed-bed reactor. The thermochemical characteristics of sludge samples were first analyzed. The results indicated that the calorific value had about 15 MJ\\/kg on an average, suggesting that it had a potential for biomass energy source.

Wen-Tien Tsai; Jeng-Hung Chang; Kuo-Jung Hsien; Yuan-Ming Chang

2009-01-01

379

Fuel assembly for the production of tritium in light water reactors  

SciTech Connect

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

Cawley, W. E.; Trapp, T. J.

1985-07-02

380

Characterization of argon-41 production at N Reactor Hanford Reservation, Washington  

Microsoft Academic Search

As a result of normal N Reactor operation, approximately 50,000 curies ; of Ar are released to the atmosphere at Hanford each year. Although the ; total population whole-body dose of 1.1 man-rem\\/year due to these Ar ; emissions is very small compared to the total population whole-body dose of ; 27,000 man-rem\\/year due to natural background, efforts are being

Cucchiara

1975-01-01

381

Advanced Resources for Catalysis Science: Workshop Results. Recommendations for a National Catalysis Research Institute. Held in Richland, Washington on September 21-22, 2004.  

National Technical Information Service (NTIS)

Twenty-seven experts-representing a broad spectrum-from national laboratories, industry, and universities participated in the Advanced Resources for Catalysis Science Workshop held at Pacific Northwest National Laboratory, Richland, Washington, September ...

D. Ray C. Peden

2004-01-01

382

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  

Microsoft Academic Search

The U.S. Department of Energy 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 (8) fuel irradiation tests are planned for the Idaho National Laboratory's (INLs) advanced test reactor (ATR). The first test in this series (AGR-1)

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

2007-01-01

383

Determination of Long-Lived Neutron Activation Products in Reactor Shielding Concrete Samples  

SciTech Connect

The results of activation studies of TRIGA research reactor concrete shielding are given. Samples made of ordinary and barytes concrete were irradiated in the reactor to simulate neutron activation in the shielding concrete. Long-lived neutron-induced gamma-ray-emitting radioactive nuclides were measured in the samples with a high-purity germanium detector. The most active long-lived radioactive nuclides in the ordinary concrete samples were found to be {sup 60}Co and {sup 152}Eu. In the barytes concrete samples, the most active long-lived radioactive nuclides were {sup 60}Co, {sup 133}Ba, and {sup 152}Eu. Activation in the concrete was also calculated using the ORIGEN2 code and compared to experimental results. Simple radioactive nuclide generation and depletion calculation using one-group cross-section libraries provided together with the ORIGEN2 code did not give conservative results. Significant discrepancies were observed for some nuclides. For accurate long-lived radioactive nuclide generation in reactor shielding, material-specific cross-section libraries should be generated and verified by measurement.

Zagar, Tomaz; Ravnik, Matjaz ['Jozef Stefan' Institute (Slovenia)

2002-10-15

384

Fission product release and fuel behavior of irradiated light water reactor fuel under severe accident conditions. The ACRR ST-1 Experiment  

SciTech Connect

The annular Core Research Reactor (ACRR) Source Term (ST) Experiment program was designed to obtain time-resolved data on the release of fission products from irradiated fuels under well-controlled light water reactor severe accident conditions. The ST-1 Experiment was the first of two experiments designed to investigate fission product release. ST-1 was conducted in a highly reducing environment at a system pressure of approximately 0.19 MPa, and at maximum fuel temperatures of about 2490 K. The data will be used for the development and validation of mechanistic fission product release computer codes such as VICTORIA.

Allen, M.D.; Stockman, H.W.; Reil, K.O. [Sandia National Labs., Albuquerque, NM (United States); Fisk, J.W. [Tills (Jack) and Associates, Inc., Albuquerque, NM (United States)

1991-11-01

385

Characterization of the retained sludge in a down-flow hanging sponge (DHS) reactor with emphasis on its low excess sludge production.  

PubMed

Experiments to characterize retained sludge in a down-flow hanging sponge (DHS) reactor fed with upflow anaerobic sludge blanket (UASB) treated sewage under moderate conditions were conducted. Plenty of oxygen was supplied through the DHS reactor without aeration and the effluent qualities after the reactor were comparable to activated sludge processes. The average excess sludge production rate was 0.09 g SS g(-1) COD removed. The DHS reactor maintained a high sludge concentration of 26.9 g VSS L(-1) sponge, resulting in a low loading rate of 0.032 g COD g(-1) VSS day(-1). The endogenous respiration rate of DHS sludge was comparable to previously reported aerobic sludges. The numbers of microfauna were one order of magnitude greater than those in activated sludge. The results indicated that low excess sludge production was attributable to the high sludge concentration, sufficient oxygen supply, adequate endogenous respiration rate, and a high density and diversity of microfauna. PMID:23567678

Onodera, Takashi; Matsunaga, Kengo; Kubota, Kengo; Taniguchi, Ryoko; Harada, Hideki; Syutsubo, Kazuaki; Okubo, Tsutomu; Uemura, Shigeki; Araki, Nobuo; Yamada, Masayoshi; Yamauchi, Masahito; Yamaguchi, Takashi

2013-05-01

386

Effect of hydraulic retention time on lactic acid production and granulation in an up-flow anaerobic sludge blanket reactor.  

PubMed

In the present work, lactic acid (LA) production performance with granulation was investigated at various hydraulic retention times (HRTs), 8-0.5h. Glucose was used as a feedstock, and anaerobic mixed cultures were inoculated in an up-flow anaerobic sludge blanket reactor. As HRT decreased, the average diameter and hydrophobicity of the granules increased from 0.31 to 3.4mm and from 17.5% to 38.3%, respectively, suggesting the successful formation of granules. With decreasing HRT, LA productivity increased up to 16.7gLA/L-fermenter/h at HRT 0.5h. The existence of rod-shaped organisms with pores and internal channels at granule surface was observed by scanning electron microscope. Next generation sequencing revealed that Lactobacillus was the dominant microorganism, accounting for 96.7% of total sequences, comprising LA-producing granules. PMID:24767539

Kim, Dong-Hoon; Lee, Mo-Kwon; Moon, Chungman; Yun, Yeo-Myeong; Lee, Wontae; Oh, Sae-Eun; Kim, Mi-Sun

2014-08-01

387

An exploratory analysis of thermal-hydraulic conditions leading to severe accidents for the New Production Heavy-Water Reactor  

SciTech Connect

This study, sponsored by the New Production Reactor (NPR) Program through the Los Alamos NPR Safety Project Office, is part of the body of severe-accident review information being developed to support the safety review of the New Production Heavy-Water Reactor (NP-HWR). The NP-HWR safety study of severe beyond-design-basis events concerns two issues related to in-vessel, sudden-energy sources: wet-core recriticality and molten-fuel-and-coolant interaction (MFCI). The configuration that will lead to recriticality and MFCI is determined by the mode and coherency of the fuel-target disruption and water contact during the accident progression. The mode and coherency are, in turn, governed by the thermal-hydraulic conditions in the assembly channel and the fuel heatup rate after the assembly channels have dried out. The results of the analysis, presented for the transients out to the time of incipient fuel melt, describe the dominant features of the transients for the two severe events. The conclusions summarize what we have learned about the controlling mechanisms and important parameters for the conditions leading up to fuel melt, identify important safety review information that may be relevant to the final design, and suggest actions needed to conduct an adequate safety review of relevant aspects of the NP-HWR.

Cheng, Teh-Chin

1992-12-01

388

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

389

Effect of transcription promoters on the optimal production of secreted protein in fed-batch reactors.  

PubMed

Production of heterologous proteins by yeast secretion imposes additional factors that need to be considered, which do not appear with production by direct expression. These include additional intracellular polypeptide processing dynamics through the secretory organelles and the protein concentration in the culture medium, which is the usual final destination of the product. Optimal control theory is applied to optimize fed-batch production of secreted protein. We maximize an objective function that includes both total production rate and product concentration. A mutant invertase is chosen as the model heterologous secretory protein. Optimal control control strategies have been obtained for the use of two different promoters for the gene transcription, a dere-pressible SUC2 promoter and a strong glycolytic GPD promoter. With the use of the strong GPD promoter, achieving maximum production occurs on the singular arc of maximum specific growth rate. As the object switches to maximum product concentration, operation occurs for longer periods of time at a slow glucose singular arc condition. The optimal control for maximizing protein production with the weak SUC2 promoter requires transitions between high and low glucose concentrations associated with multiple distinct singular arc conditions. For maximum product concentration, the high concentration branches of the singular arc supporting maximum growth rate and maximum secretion rate disappear. Operation stays essentially on the low glucose concentration branch of the singular arc, which maximizes the protein production rate and minimizes the dilution of the broth product concentration. PMID:1366871

Park, S; Ramirez, W F

1990-01-01

390

Lipase-catalyzed interesterification of high oleic sunflower oil and fully hydrogenated soybean oil comparison of batch and continuous reactor for production of zero trans shortening fats  

Microsoft Academic Search

Lipase-catalyzed interesterification of high oleic sunflower oil (HO) and fully hydrogenated soybean oil (FHSBO) at different weight ratios (55:45, 60:40, 65:35 and 70:30, HO:FHSBO) was carried out in both a batch-type reactor (BA) and a packed-bed reactor (PBR) to produce zero trans shortening. Interesterified products in both PBR and BA consisted of 3446g\\/100g saturated fatty acids (SFA) (mainly stearic acid)

D. Li; P. Adhikari; J.-A. Shin; J.-H. Lee; Y.-J. Kim; X.-M. Zhu; J.-N. Hu; J. Jin; C. C. Akoh; K.-T. Lee

2010-01-01

391

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

392

Simultaneous biohydrogen production and starch wastewater treatment in an acidogenic expanded granular sludge bed reactor by mixed culture for long-term operation  

Microsoft Academic Search

The biofilm-based expanded granular sludge bed (EGSB) reactor was developed to treat starch-containing wastewater and simultaneously recovery hydrogen by mixed microbial culture. Granular activated carbon (GAC) was used as the support media. Operating at the temperature of 30C for over 400 days (data not shown), the EGSB reactor presented high efficiency in hydrogen production and COD removal ability. The maximum

Wan-Qian Guo; Nan-Qi Ren; Zhao-Bo Chen; Bing-Feng Liu; Xiang-Jing Wang; Wen-Sheng Xiang; Jie Ding

2008-01-01

393

Changes in product formation and bacterial community by dilution rate on carbohydrate fermentation by methanogenic microflora in continuous flow stirred tank reactor  

Microsoft Academic Search

Changes in product formation during carbohydrate fermentation by anaerobic microflora in a continuous flow stirred tank reactor were investigated with respect to the dilution rate in the reactor. In the fermentation by methanogenic microflora, stable methane fermentation, producing methane and carbon dioxide, was observed at relatively low dilution rates (less than 0.33 d-1 on glucose and 0.20 d-1 on cellulose).

Y. Ueno; S. Haruta; M. Ishii; Y. Igarashi

2001-01-01

394

Production of ultrapure hydrogen via utilizing fluidization concept from coupling of methanol and benzene synthesis in a hydrogen-permselective membrane reactor  

Microsoft Academic Search

In this work, a novel fluidized-bed thermally coupled membrane reactor has been proposed for simultaneous hydrogen, methanol and benzene production. Methanol synthesis is carried out in exothermic side which is a fluidized-bed reactor and supplies the necessary heat for the endothermic side. Dehydrogenation of cyclohexane is carried out in endothermic side with hydrogen-permselective Pd\\/Ag membrane wall. Selective permeation of hydrogen

M. R. Rahimpour; M. Bayat

2011-01-01

395

Activation of Canadian coals in a fixed-bed reactor: effect of the particle size on product quality  

SciTech Connect

Three Canadian coals, namely, Bienfait lignite, Montgomery sub-bituminous C, and Coal Valley high volatile bituminous C were activated in a fixed-bed reactor. For each coal, two different sizes of particles in the ranges of 0-1.25 mm (fines) and 1.25-2.5 mm (granules) along with cylindrical pellets of 3.18 mm in diameter and 7{+-}2 mm long were activated. The qualities of the products were determined by measuring iodine and methylene blue numbers, specific Brunauer-Emmett-Teller (BET) surface areas, bulk densities, and ash contents. The specific surface areas and iodine and methylene blue numbers of bituminous coal products were lower than the values obtained with the lignite and sub-bituminous coals, although the product yields were higher. Products obtained from pellets were found to have superior quality compared to that obtained from fines. The ash content of the feed coal influences the quality of the product activated carbon. It was established that a first-order reaction between steam and coal pellets occurred in the process. The activation energies for the process were also determined. 17 refs., 12 figs., 4 tabs.

Ajay K. Dalai; Narayan C. Pradhan; Jian Liu; Amitabha Majumdar; Eric L. Tollefson [University of Saskatchewan, Saskatoon, SK (Canada). Department of Chemical Engineering

2008-07-15

396

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.

397

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) [San Diego, CA; Johnson, Jr., William R. (San Diego, CA)

1985-01-01

398

Environmental assessment of SP-100 ground engineering system test site: Hanford Site, Richland, Washington  

SciTech Connect

The US Department of Energy (DOE) proposes to modify an existing reactor containment building (decommissioned Plutonium Recycle Test Reactor (PRTR) 309 Building) to provide ground test capability for the prototype SP-100 reactor. The 309 Building (Figure 1.1) is located in the 300 Area on the Hanford Site in Washington State. The National Environmental Policy Act (NEPA) requires that Federal agencies assess the potential impacts that their actions may have on the environment. This Environmental Assessment describes the consideration given to environmental impacts during reactor concept and test site selection, examines the environmental effects of the DOE proposal to ground test the nuclear subsystem, describes alternatives to the proposed action, and examines radiological risks of potential SP-100 use in space. 73 refs., 19 figs., 7 tabs.

Not Available

1988-12-01

399

Environmental assessment of SP-100 ground engineering system test site: Hanford Site, Richland, Washington  

NASA Astrophysics Data System (ADS)

The US Department of Energy (DOE) proposes to modify an existing reactor containment building (decommissioned Plutonium Recycle Test Reactor (PRTR) 309 Building) to provide ground test capability for the prototype SP-100 reactor. The 309 Building (Figure 1.1) is located in the 300 Area on the Hanford Site in Washington State. The National Environmental Policy Act (NEPA) requires that Federal agencies assess the potential impacts that their actions may have on the environment. This Environmental Assessment describes the consideration given to environmental impacts during reactor concept and test site selection, examines the environmental effects of the DOE proposal to ground test the nuclear subsystem, describes alternatives to the proposed action, and examines radiological risks of potential SP-100 use in space.

1988-12-01

400

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

401

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 30C. 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 4010-4 mmol/hUGO 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

402

The possibility of steam explosions for a misseated septifoil in the SRS K Production reactor  

SciTech Connect

Control rods in the Savannah River Site's K-reactor are contained within housings composed of seven channels ( septifoils'). Each septifoil is suspended from the top of the reactor and is normally seated on an upflow pin that channels coolant to the septifoil. Forced flow to the septifoil would be eliminated in the unlikely event of a septifoil misseated upon installation, i.e., if the septifoil is not aligned with its upflow pin. If this event were not detected, control rod melting and the interaction of molten metal with water might occur. This paper describes a methodology used to address the issues of steam explosions that might arise by this mechanism. The probability of occurrence of a damaging steam explosion given a misseated septifoil was found to be extremely low. The primary reasons are: (1) the high probability that melting will not occur, (2) the possibility of material holdup by contact with the outer septifoil housing, (3) the relative shallowness of the pool of water into which molten material might fall, (4) the probable absence of a trigger, and (5) the relatively large energy release required to damage a nearby fuel assembly. The methodology is based upon the specification of conditions prevailing within the septifoil at the time molten material is expected to contact water, and upon information derived from the available experimental data base, supplemented by recent prototypic experiments.

Allison, D.K.; Hyder, M.L.; Yau, W.W.F. (Westinghouse Savannah River Co., Aiken, SC (United States)); Smith, D.C. (Science Applications International Corp., Albuquerque, NM (United States))

1992-01-01

403

The possibility of steam explosions for a misseated septifoil in the SRS K Production reactor  

SciTech Connect

Control rods in the Savannah River Site`s K-reactor are contained within housings composed of seven channels (`septifoils`). Each septifoil is suspended from the top of the reactor and is normally seated on an upflow pin that channels coolant to the septifoil. Forced flow to the septifoil would be eliminated in the unlikely event of a septifoil misseated upon installation, i.e., if the septifoil is not aligned with its upflow pin. If this event were not detected, control rod melting and the interaction of molten metal with water might occur. This paper describes a methodology used to address the issues of steam explosions that might arise by this mechanism. The probability of occurrence of a damaging steam explosion given a misseated septifoil was found to be extremely low. The primary reasons are: (1) the high probability that melting will not occur, (2) the possibility of material holdup by contact with the outer septifoil housing, (3) the relative shallowness of the pool of water into which molten material might fall, (4) the probable absence of a trigger, and (5) the relatively large energy release required to damage a nearby fuel assembly. The methodology is based upon the specification of conditions prevailing within the septifoil at the time molten material is expected to contact water, and upon information derived from the available experimental data base, supplemented by recent prototypic experiments.

Allison, D.K.; Hyder, M.L.; Yau, W.W.F. [Westinghouse Savannah River Co., Aiken, SC (United States); Smith, D.C. [Science Applications International Corp., Albuquerque, NM (United States)

1992-05-01

404

Secondary charged particle activation method for measuring the tritium production rate in the breeding blankets of a fusion reactor  

NASA Astrophysics Data System (ADS)

In this work, a new passive technique has been developed for measuring the tritium production rate in ITER (International Thermonuclear Experimental Reactor) test blanket modules. This method is based on the secondary charged particle activation, in which the irradiated sample contains two main components: a tritium producing target (6Li or 7Li) and an indicator nuclide, which has a relatively high cross-section for an incoming tritium particle (triton). During the neutron irradiation, the target produces a triton, which has sufficiently high energy to cause the so-called secondary charged particle activation on an indicator nuclide. If the product of this reaction is a radioactive nuclide, its activity must be proportional to the amount of generated tritium. A comprehensive set of irradiations were performed at the Training Reactor of the Budapest University of Technology and Economics. The following charged particle reactions were observed and investigated: 27Al(t,p)29Al; 26Mg(t,p)28Mg; 26Mg(t,n)28Al; 32S(t,n)34mCl; 16O(t,n)18F; and O(t,?)18N17. The optimal atomic ratio of the indicator elements and 6Li was also investigated. The reaction rates were estimated using calculations with the MCNPX Monte Carlo particle transport code. The trend of the measured and the simulated data are in good agreement, although accurate data for triton induced reaction cross-sections cannot be found in the literature. Once the technique is calibrated with a reference LSC (Liquid Scintillation Counting) measurement, a new passive method becomes available for tritium production rate measurements.

Rovni, Istvn; Szieberth, Mt; Fehr, Sndor

2012-10-01

405

Bacterial cellulose production under oxygen-enriched air at different fructose concentrations in a 50-liter, internal-loop airlift reactor  

Microsoft Academic Search

Bacterial cellulose (BC) production by Acetobacter xylinum subsp. sucrofermentans BPR2001 was carried out in a 50-l internal-loop airlift reactor in air at an initial fructose concentration of 40 g\\/l. The BC production rate was 0.059 g\\/l per h. When oxygen-enriched air was supplied instead of air, the BC production rate increased to 0.093 g\\/l per h, and the BC yield

Y. Chao; Y. Sugano; M. Shoda

2001-01-01

406

Licensing for tritium production in a commercial light water reactor: A utility view  

Microsoft Academic Search

In a December 1995 Record of Decision for the Final Programmatic Environmental Impact Statement for Tritium Supply and Recycling, the US Department of Energy (DOE) decided to pursue a dual-track approach to determine the preferred option for future production of tritium for the nuclear weapons stockpile. The two options to be pursued were (a) the Accelerator Production of Tritium and

J. S. Chardos; G. C. Sorensen; L. W. Erickson

2000-01-01

407

Effects of pH profiles on nisin production in biofilm reactor  

Microsoft Academic Search

Apart from its widely accepted commercial applications as a food preservative, nisin emerges as a promising alternative in medical applications for bacterial infection in both humans and livestock. Improving nisin production through optimization of fermentation parameters would make nisin more cost-effective for various applications. Since nisin production by Lactococcus lactis NIZO 22186 was highly influenced by the pH profile employed

Thunyarat Pongtharangkul; Ali Demirci

2006-01-01

408

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

409

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 52.1C, 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.

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

410

Interfacing the tandem mirror reactor to the sulfur-iodine process for hydrogen production  

SciTech Connect

The blanket is linked to the H/sub 2/SO/sub 4/ vaporization units and SO/sub 3/ decomposition reactor with either sodium or helium. The engineering and safety problems associated with these choices are discussed. This H/sub 2/SO/sub 4/ step uses about 90% of the TMR heat and is best close-coupled to the nuclear island. The rest of the process we propose to be driven by steam and does not require close-coupling. The sodium loop coupling seems to be preferable at this time. We can operate with a blanket around 1200 K and the SO/sub 3/ decomposer around 1050 K. This configuration offers double-barrier protection between Li-Na and the SO/sub 3/ process gases. Heat pipes offer an attractive alternate to provide an additional barrier, added modularity for increased reliability, and tritium concentration and isolation operations with very little thermal penalty.

Galloway, T.R.

1980-06-02

411

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.

1983-09-01

412

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

413

Use of disposable reactors to generate inoculum cultures for E. coli production fermentations.  

PubMed

Disposable technology is being used more each year in the biotechnology industry. Disposable bioreactors allow one to avoid expenses associated with cleaning, assembly and operations, as well as equipment validation. The WAVE bioreactor is well established for Chinese Hamster Ovary (CHO) production, however, it has not yet been thoroughly tested for E. coli production because of the high oxygen demand and temperature maintenance requirements of that platform. The objective of this study is to establish a robust process to generate inoculum for E. coli production fermentations in a WAVE bioreactor. We opted not to evaluate the WAVE system for production cultures because of the high cell densities required in our current E. coli production processes. Instead, the WAVE bioreactor 20/50 system was evaluated at laboratory scale (10-L) to generate inoculum with target optical densities (OD(550)) of 15 within 7-9 h (pre-established target for stainless steel fermentors). The maximum settings for rock rate (40 rpm) and angle (10.5) were used to maximize mass transfer. The gas feed was also supplemented with additional oxygen to meet the high respiratory demand of the culture. The results showed that the growth profiles for the inoculum cultures were similar to those obtained from conventional stainless steel fermentors. These inoculum cultures were subsequently inoculated into 10-L working volume stainless steel fermentors to evaluate the inocula performance of two different production systems during recombinant protein production. The results of these production cultures using WAVE inocula showed that the growth and recombinant protein production was comparable to the control data set. Furthermore, an economic analysis showed that the WAVE system would require less capital investment for installation and operating expenses would be less than traditional stainless steel systems. PMID:20730774

Mahajan, Ekta; Matthews, Timothy; Hamilton, Ryan; Laird, Michael W

2010-01-01

414

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 heatingthe same process used to render wood into charcoal, caramelize sugar, and dry roast coffee and beans. RTIs catalytic biomass pyrolysis differs from conventional flash pyrolysis in that its end product contains less oxygen, metals, and nitrogenall 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

415

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

416

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

417

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

418

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

419

Feed frequency in a Sequencing Batch Reactor strongly affects the production of polyhydroxyalkanoates (PHAs) from volatile fatty acids.  

PubMed

The production of polyhydroxyalkanoates (PHAs) by activated sludge selected in a sequencing batch reactor (SBR) has been investigated. Several SBR runs were performed at the same applied organic load rate (OLR), hydraulic retention time (HRT) and feed concentration (8.5gCODL(-1) of volatile fatty acids, VFAs) under aerobic conditions. The effect of the feeding time was only evaluated with a cycle length of 8h; for this particular cycle length, an increase in the storage response was observed by increasing the rate at which the substrate was fed into the reactor (at a fixed feeding frequency). Furthermore, a significantly stronger effect was observed by decreasing the cycle length from 8h to 6h and then to 2h, changing the feed frequency or changing the organic load given per cycle (all of the other conditions remained the same): the length of the feast phase decreased from 26 to 20.0 and then to 19.7% of the overall cycle length, respectively, due to an increase in the substrate removal rate. This removal rate was high and similar for the runs with cycle lengths of 2h and 6h in the SBR. This result was due to an increase in the selective pressure and the specific storage properties of the selected biomass. The highest polymer productivity after long-term accumulation batch tests was 1.7gPHAL(-1)d(-1), with PHA content in the biomass of approximately 50% on a COD basis under nitrogen limitation. The DGGE profiles showed that the good storage performance correlated to the development of Lampropedia hyalina, which was only observed in the SBR runs characterized by a shorter cycle length. PMID:24184912

Valentino, Francesco; Beccari, Mario; Fraraccio, Serena; Zanaroli, Giulio; Majone, Mauro

2014-06-25

420

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 51.4gCODL(-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 2.0mol-H2mol(-1)-glucose at an OLR of 25.7gCODL(-1)d(-1). Although, a maximum hydrogen production rate of 23.40.9LH2L(-1)d(-1) was achieved in the UAnPBR2 at an OLR of 51.4gCODL(-1)d(-1), the hydrogen yield dropped by 50% to around 1mol-H2mol(-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 Jnior, Antnio Djalma Nunes; Zaiat, Marcelo; Gupta, Medhavi; Elbeshbishy, Elsayed; Hafez, Hisham; Nakhla, George

2014-07-01

421

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

422

Development of a phenomena identification and ranking table for thermal-hydraulic phenomena during a double-ended guillotine break LOCA in an SRS production reactor  

SciTech Connect

A rising level of scrutiny is being directed toward the Savannah River Site (SRS) production reactors. Improved calculational capabilities are being developed to provide a best estimate analytical process to determine the safe operating margins of the reactors. The Code Scaling, Applicability, and Uncertainty (CSAU) methodology, developed by the US Nuclear Regulatory Commission to support best estimate simulations, is being applied to the best estimate limits analysis for the SRS production reactors. One of the foundational parts of the method is the identification and ranking of all the processes that occur during the specific limiting scenario. The phenomena ranking is done according to their importance to safety criteria during the transient and is used to focus the uncertainty analysis on a sufficient, yet cost effective scope of work. This report documents the thermal-hydraulic phenomena that occur during a limiting break in an SRS production reactor and their importance to the uncertainty in simulations of the reactor behavior. 9 refs., 14 figs., 10 tabs.

Hanson, R.G.; Ortiz, M.G.; Bolander, M.A.; Wilson, G.E.

1989-07-01

423

Environmental consequences of postulated plutonium releases from Exxon Nuclear MOFP, Richland, Washington, as a result of severe natural phenomena  

SciTech Connect

Potential environmental consequences in terms of radiation dose to people are presented for postulated plutonium releases caused by severe natural phenomena at the Exxon Nuclear Company Mixed Oxide Fabrication Plant (MOFP), Richland, Washington. The severe natural phenomena considered are earthquakes, tornadoes, high straight-line winds, and floods. Maximum plutonium deposition values are given for significant locations around the site. All important potential exposure pathways are examined. The most likely 50-year committed dose equivalents are given for the maximum-exposed individual and the population within a 50-mile radius of the plant. The maximum plutonium deposition values most likely to occur offsite are also given.

Jamison, J.D.; Watson, E.C.

1980-02-01

424

ELIXYS - a fully automated, three-reactor high-pressure radiosynthesizer for development and routine production of diverse PET tracers  

PubMed Central

Background Automated radiosynthesizers are vital for routine production of positron-emission tomography tracers to minimize radiation exposure to operators and to ensure reproducible synthesis yields. The recent trend in the synthesizer industry towards the use of disposable kits aims to simplify setup and operation for the user, but often introduces several limitations related to temperature and chemical compatibility, thus requiring reoptimization of protocols developed on non-cassette-based systems. Radiochemists would benefit from a single hybrid system that provides tremendous flexibility for development and optimization of reaction conditions while also providing a pathway to simple, cassette-based production of diverse tracers. Methods We have designed, built, and tested an automated three-reactor radiosynthesizer (ELIXYS) to provide a flexible radiosynthesis platform suitable for both tracer development and routine production. The synthesizer is capable of performing high-pressure and high-temperature reactions by eliminating permanent tubing and valve connections to the reaction vessel. Each of the three movable reactors can seal against different locations on disposable cassettes to carry out different functions such as sealed reactions, evaporations, and reagent addition. A reagent and gas handling robot moves sealed reagent vials from storage locations in the cassette to addition positions and also dynamically provides vacuum and inert gas to ports on the cassette. The software integrates these automated features into chemistry unit operations (e.g., React, Evaporate, Add) to intuitively create synthesis protocols. 2-Deoxy-2-[18F]fluoro-5-methyl-?-l-arabinofuranosyluracil (l-[18F]FMAU) and 2-deoxy-2-[18F]fluoro-?-d-arabinofuranosylcytosine (d-[18F]FAC) were synthesized to validate the system. Results l-[18F]FMAU and d-[18F]FAC were successfully synthesized in 165 and 170 min, respectively, with decay-corrected radiochemical yields of 46% 1% (n = 6) and 31% 5% (n = 6), respectively. The yield, repeatability, and synthesis time are comparable to, or better than, other reports. d-[18F]FAC produced by ELIXYS and another manually operated apparatus exhibited similar biodistribution in wild-type mice. Conclusion The ELIXYS automated radiosynthesizer is capable of performing radiosyntheses requiring demanding conditions: up to three reaction vessels, high temperatures, high pressures, and sensitive reagents. Such flexibility facilitates tracer development and the ability to synthesize multiple tracers on the same system without customization or replumbing. The disposable cassette approach simplifies the transition from development to production.

2013-01-01

425

PRODUCTION OF VOID AND PRESSURE BY FISSION TRACK NUCLEATION OF RADIOLYTIC GAS BUBBLES DURING POWER BURSTS IN A SOLUTION REACTOR  

Microsoft Academic Search

The Kinetic Experiment on Water Boiler (KEWB) reactor is a 50-kw aqueous ;\\u000a homogeneous research reactor which was designed to study the safety ;\\u000a characteristics and dynamic behavior of this class of reactors. When the reactor ;\\u000a is placed on a short-period power transient, its aqueous uranyl sulfate fuel ;\\u000a solution becomes rapidly supersaturated with H gas produced by the

P. Spiegler; C. F. Jr. Bumpus; A. Norman

1962-01-01

426

Xylitol production from sugarcane bagasse hydrolyzate in fluidized bed reactor. Effect of air flowrate.  

PubMed

Cells of Candida guilliermondii immobilized onto porous glass spheres were cultured batchwise in a fluidized bed bioreactor for xylitol production from sugarcane bagasse hemicellulose hydrolyzate. An aeration rate of only 25 mL/min ensured minimum yields of xylose consumption (0.60) and biomass production (0.14 g(DM)/g(Xyl)), as well as maximum xylitol yield (0.54 g(Xyt)/g(Xyl)) and ratio of immobilized to total cells (0.83). These results suggest that cell metabolism, although slow because of oxygen limitation, was mainly addressed to xylitol production. A progressive increase in the aeration rate up to 140 mL/min accelerated both xylose consumption (from 0.36 to 0.78 g(Xyl)/L.h) and xylitol formation (from 0.19 to 0.28 g(Xyt)/L.h) but caused the fraction of immobilized to total cells and the xylitol yield to decrease up to 0.22 and 0.36 g(Xyt)/g(Xyl), respectively. The highest xylitol concentration (17.0 g(Xyt)/L) was obtained at 70 mL/min, but the specific xylitol productivity and the xylitol yield were 43% and 22% lower than the corresponding values obtained at the lowest air flowrate, respectively. The concentrations of consumed substrates and formed products were used in material balances to evaluate the xylose fractions consumed by C. guilliermondii for xylitol production, complete oxidation through the hexose monophosphate shunt, and cell growth. The experimental data collected at variable oxygen level allowed estimating a P/O ratio of 1.35 mol(ATP)/mol(O) and overall ATP requirements for biomass growth and maintenance of 3.4 mol(ATP)/C-mol(DM). PMID:12892483

Santos, J C; Carvalho, W; Silva, S S; Converti, A

2003-01-01

427

Effect of operational pH on biohydrogen production from food waste using anaerobic batch reactors.  

PubMed

This study was performed to investigate the influence of operational pH on dark H2 fermentation of food waste by employing anaerobic batch reactors. The highest maximum H2 yield was 1.63 mol H2/mol hexoseadded at operational pH 5.3, whereas the lowest maximum H2 yield was 0.88 mol H2/mol hexoseadded at operational pH 7.0. With decreasing operational pH values, the n-butyrate concentration tended to increase and the acetate concentration tended to decrease. The highest hydrogen conversion efficiency of 11.3% was obtained at operational pH 5.3, which was higher than that (8.3%) reported by a previous study (Kim et al. (2011) 'Effect of initial pH independent of operational pH on hydrogen fermentation of food waste', Bioresource Technology 102 (18), 8646-8652). The new result indicates that the dark fermentation of food waste was stable and efficient in this study. Fluorescence in situ hybridization (FISH) analysis showed that Clostridium species Cluster I accounted for 84.7 and 13.3% of total bacteria at operational pH 5.3 and pH 7.0, respectively, after 48 h operation. PMID:24804664

Lee, Chaeyoung; Lee, Sewook; Han, Sun-Kee; Hwang, Sunjin

2014-01-01

428

Optimization of biodiesel production in a hydrodynamic cavitation reactor using used frying oil.  

PubMed

The present work demonstrates the application of a hydrodynamic cavitation reactor for the synthesis of biodiesel with used frying oil as a feedstock. The synthesis involved the transesterification of used frying oil (UFO) with methanol in the presence of potassium hydroxide as a catalyst. The effect of geometry and upstream pressure of a cavitating orifice plate on the rate of transesterification reaction has been studied. It is observed that the micro level turbulence created by hydrodynamic cavitation somewhat overcomes the mass transfer limitations for triphasic transesterification reaction. The significant effects of upstream pressure on the rate of formation of methyl esters have been seen. It has been observed that flow geometry of orifice plate plays a crucial role in process intensification. With an optimized plate geometry of 2mm hole diameter and 25 holes, more than 95% of triglycerides have been converted to methyl esters in 10 min of reaction time with cavitational yield of 1.28 10(-3) (Grams of methyl esters produced per Joule of energy supplied). The potential of UFO to produce good quality methyl esters has been demonstrated. PMID:22922070

Ghayal, Dyneshwar; Pandit, Aniruddha B; Rathod, Virendra K

2013-01-01

429

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

430

Studies of Smallmouth Black Bass (Micropterus Dolomieu) in the Columbia River near Richland, Washington  

Microsoft Academic Search

Observations on smallmouth black bass, Micropterus dolomieu, of the Columbia River were possible because of a transplantation program undertaken by local sportsmen and because of studies made by the U. S. Public Health Service and the General Electric Company to evaluate effects of the radioactive effluent from the Hanford reactors. The average bass caught with sport-fishing gear was 15 1\\/2

Croswell Henderson; Richard F. Foster

1957-01-01

431

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

432

Process for the Removal of Radioactive Corrosion Products from the Inner Surfaces of a Nuclear Reactor.  

National Technical Information Service (NTIS)

A solution is added to the coolant which has a higher oxygen concentration than water and causes the dissolution of the corrosion products in the coolant; moreover that the coolant pressure is reduced to atmospheric pressure, and the coolant containing th...

H. Holzer

1985-01-01

433

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 ...

434

Nuclear-Based Hydrogen Production with a Thermochemical Copper-Chlorine Cycle and Supercritical Water Reactor  

Microsoft Academic Search

Efficient and sustainable methods of clean fuel production are needed in Ontario (and elsewhere) in the face of depleting oil reserves and the need to reduce carbon dioxide emissions. With commitments for a hydrogen village, a hydrogen airport and a hydrogen corridor, Ontario has already begun to move toward a hydrogen-fueled economy. However, a key missing element is a large-scale

M. A. Rosen; F. Naterer; R. Sadhankar; S. Suppiah

435

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

National Technical Information Service (NTIS)

INL developed a bench scale modular hybrid plasma system for gas phase nanomaterials synthesis. The system was being optimized for WO3 nanoparticles production and scale model projection to a 300 kW pilot system. During the course of technology developmen...

P. C. Kong

2011-01-01

436

Control of Corrosion Product Movement and Deposited Activities in Reactor Circuits.  

National Technical Information Service (NTIS)

The transport of corrosion products and the resulting deposit formation, together with the transport of radionuclides and their fixation on the walls, are studied in a pressurized water loop with in-pile fuel element. The release rates of chemical species...

J. Rozenberg L. Dolle R. Darras

1976-01-01

437

Radioactive Fission Product Release from the Failed Fuel Elements at the VK-50 Reactor.  

National Technical Information Service (NTIS)

The dynamics of release of radioactive gaseous fission products (GFP) namely exp 133 Xe, exp 135 Xe, sup(135m)Xe, exp 138 Xe, sup(85m)Kr, exp 87 Kr, exp 88 Kr, exp 89 Kr, exp 131 I, exp 132 I, exp 133 I, exp 134 I and exp 135 I from failed fuel elements d...

A. V. Vasilishchuk V. V. Konyashov E. I. Shkokov Y. V. Chechetkin E. K. Yakshin

1982-01-01

438

Application possibilities of a new generator concept for 99m Tc production by means of the Triga-Mark III reactor in Mexico  

Microsoft Academic Search

A new concept of prefabricated99mTc generator has been experimentally tested as a possible procedure for local production of99mTc for medical purposes by means of the ININ-Salazar \\/Mexico\\/ Triga-Mark III reactor working at 1 MW.

K. Svoboda; J. Lezama; J. Tendilla; F. Melichar; M. Tympl

1985-01-01

439

Continuous production of gibberellic acid in a fixed-bed reactor by immobilized mycelia of Gibberella fujikuroi in calcium alginate beads  

Microsoft Academic Search

The continuous production of gibberellic acid with immobilized mycelia of Gibberella fujikuroi was maintained over a hundred days in a tubular fixed-bed reactor. Free mycelium at the beginning of the storage phase was harvested from G. fujikuroi shake-flask culture and was immobilized by ionotropic gelation in calcium alginate beads.

Jos Edmundo Nava Saucedo; Jean-Nol Barbotin; Daniel Thomas

1989-01-01

440

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

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