60 Matching Results

Search Results

Advanced search parameters have been applied.

Modular Isotopic Thermoelectric Generator (MITG) Design and Development, Part A-E. Original was presented at 1983 Intersociety Energy Conversion Engineering Conference (IECEC)

Description: Advanced RTG concepts utilizing improved thermoelectric materials and converter concepts are under study at Fairchild for DOE. The design described here is based on DOE's newly developed radioisotope heat source, and on an improved silicon-germanium material and a multicouple converter module under development at Syncal. Fairchild's assignment was to combine the above into an attractive power system for use in space, and to assess the specific power and other attributes of that design. The resultant design is highly modular, consisting of standard RTG slices, each producing 24 watts at the desired output voltage of 28 volt. Thus, the design could be adapted to various space missions over a wide range of power levels, with little or no redesign. Each RTG slice consists of a 250-watt heat source module, eight multicouple thermoelectric modules, and standard sections of insulator, housing, radiator fins, and electrical circuit. The design makes it possible to check each thermoelectric module for electrical performance, thermal contact, leaktightness, and performance stability, after the generator is fully assembled; and to replace any deficient modules without disassembling the generator or perturbing the others. The RTG end sections provide the spring-loaded supports required to hold the free-standing heat source stack together during launch vibration. Detailed analysis indicates that the present generation of RTGs, using the same heat source modules. There is a duplicate copy of this document. OSTI has a copy of this paper.
Date: April 29, 1983
Creator: Schock, A.
Partner: UNT Libraries Government Documents Department

Thermionic cogeneration burner assessment study. Third quarterly technical progress report, April-June, 1983

Description: The specific tasks of this study are to mathematically model the thermionic cogeneration burner, experimentally confirm the projected energy flows in a thermal mock-up, make a cost estimate of the burner, including manufacturing, installation and maintenance, review industries in general and determine what groups of industries would be able to use the electrical power generated in the process, select one or more industries out of those for an in-depth study, including determination of the performance required for a thermionic cogeneration system to be competitive in that industry. Progress is reported. (WHK)
Date: January 1, 1983
Partner: UNT Libraries Government Documents Department

Pu-238 fuel form activities, January 1-31, 1983

Description: This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.
Date: March 1, 1983
Partner: UNT Libraries Government Documents Department

SP-100 coated-particle fuel development. Phase I. Final report

Description: This document is the final report of Phase I of the SP-100 Coated-Particle Fuel Development Program conducted by GA Technologies Inc. for the US Department of Energy under contract DE-AT03-82SF11690. The general objective of the study conducted between September and December 1982 was to evaluate coated-particle type fuel as an alternate or backup fuel to the UO/sub 2/ tile-and-fin arrangement currently incorporated into the reference design of the SP-100 reactor core. This report presents and discusses the following topics in the order listed: the need for an alternative fuel for the SP-100 nuclear reactor; an abbreviated description of the reference and coated-particle fuel module concepts; the bases and results of the study and analysis leading to the preliminary design of a coated particle suitable for the SP-100 space power reactor; incorporation of the fuel particles into compacts and heat-pipe-cooled modules; initial efforts and plans to fabricate coated-particle fuel and fuel compacts; the design and performance of the proposed alternative core relative that of the reference fuel; and a summary of critical issues and conclusions consistent with the level of effort and duration of the study.
Date: March 1, 1983
Partner: UNT Libraries Government Documents Department

Space-reactor system and subsystem investigations: cost and schedule estimates for reactor and shield subsystems technology development. SP-100 Program

Description: This report presents cost and schedule estimates of the technology development for reactor and shielding subsystems of a 100-kWe class space reactor electric system. The subsystems technology development (which includes reactor and shield subsystems ground testing) is supported by materials and processes development and component development. For the purpose of the cost estimate, seven generic types of reactor subsystems were used: uranium-zirconium hydride, NaK-cooled thermal reactor; lithium-cooled, refractory-clad fast reactor; Na- or K-cooled fast reactor; in-core thermionic reactor; inert gas-cooled particle fuel reactor; inert gas-cooled metal-clad fast reactor; and heat pipe-cooled fast reactor. Also three levels of technology were included for each of the generic types of reactor subsystem: current, improved, and advanced. The data in this report encompass all these technology levels. The shielding subsystem uses both gamma (heavy-metal) and neutron (hydrogenous material) shields. The shields considered in this report would be used in conjunction with unmanned payloads.
Date: June 30, 1983
Creator: Determan, W.R.; Harty, R.B. & Hylin, C.
Partner: UNT Libraries Government Documents Department

Revised MITG design, fabrication procedure, and performance predictions

Description: The design, analysis, and key features of the Modular Isotopic Thermoelectric Generator (MITG) were described in a 1981 IECEC paper; and the design, fabrication, testing, and post-test analysis of test assemblies simulating prototypical MITG modules were described in preceding papers in these proceedings. These analyses succeeded in identifying and explaining the principal causes of thermal-stress problems encountered in the tests, and in confirming the effectiveness of design changes for alleviating them. The present paper presents additional design improvements for solving these and other problems, and describes new thermoelectric material properties generated by independent laboratories over the past two years. Based on these changes and on a revised fabrication procedure, it presents a reoptimization of the MITG design and computes the power-to-weight ratio for the revised design. That ratio is appreciably lower than the 1981 prediction, primarily because of changes in material properties; but it is still much higher than the specific power of current-generation RTGs.
Date: January 1, 1983
Creator: Schock, A.
Partner: UNT Libraries Government Documents Department

SP-100 Program: space reactor system and subsystem investigations

Description: For a space reactor power system, a comprehensive safety program will be required to assure that no undue risk is present. This report summarizes the nuclear safety review/approval process that will be required for a space reactor system. The documentation requirements are presented along with a summary of the required contents of key documents. Finally, the aerospace safety program conducted for the SNAP-10A reactor system is summarized. The results of this program are presented to show the type of program that can be expected and to provide information that could be usable in future programs.
Date: September 30, 1983
Creator: Harty, R.B.
Partner: UNT Libraries Government Documents Department

Thermionic cogeneration burner assessment study performance analysis results

Description: The purpose of this contract was to (1) test and evaluate two of the more important engineering aspects of designing and building thermionic cogeneration burners (TCB's); (2) make a cost and performance estimate of the TCB; and identify and evaluate industries where TCB's could be installed and where that the electrical power (dc) produced by the TCB's would be used directly in the process. The results of the performance analysis are detailed.
Date: December 1, 1983
Partner: UNT Libraries Government Documents Department

Some scoping experiments for a space reactor

Description: Some scoping experiments were performed to evaluate fuel performance in a lithium heat pipe reactor operating at a nominal 1500K heat pipe temperature. Fuel-coolant and fuel-coolant-clad relationships showed that once a failed heat pipe occurs temperatures can rise high enough so that large concentrations of uranium can be transported by the vapor phase. Upon condensation this uranium would be capable of penetrating heat pipes adjacent to the failed pipe. The potential for propagation of failure exists with UO/sub 2/ and a lithium heat pipe. Changing the composition of the metal of the heat pipe would have only a second order effect on the kinetics of the failure mechanism. Uranium carbide and nitride were considered as potential fuels which are nonreactive in a lithium environment. At high temperatures the nitride would be favored because of its better compatibility with potential cladding materials. Compositions of UN with small additions of YN appear to offer very attractive properties for a compact high temperature high power density reactor.
Date: July 7, 1983
Creator: Alexander, C.A. & Ogden, J.S.
Partner: UNT Libraries Government Documents Department

A review of plutonium environmental data with a bibliography for use in risk assessments

Description: Plutonium fueled radioisotopic heat sources find space, terrestrial, and undersea applications to generate electrical power. Such systems under postulated accident conditions could release radioactivity into the environment resulting in risks to the general population in the form of radiological doses and associated health effects. The evaluation of the radiological impact of postulated scenarios involving releases of activity into the environment includes identification of postulated accident release modes, including the probability of release and the release location; source term definition, including the activity of each radionuclide released and the corresponding chemical form and particle size distribution; analysis of the environmental behavior of the released radioactivity to determine the concentrations in environmental media (air, soil, and water) as a function of time; and analysis of the interaction between the environmental concentrations and man, leading to ingestion, inhalation, and external doses through each environmental exposure pathway. 443 refs., 2 figs., 4 tabs.
Date: June 15, 1983
Creator: Bartram, B.W. & Wilkinson, M.J.
Partner: UNT Libraries Government Documents Department

Space nuclear power and man's extraterrestrial civilization

Description: This paper examines leading space nuclear power technology candidates. Particular emphasis is given the heat-pipe reactor technology currently under development at the Los Alamos National Laboratory. This program is aimed at developing a 10-100 kWe, 7-year lifetime space nuclear power plant. As the demand for space-based power reaches megawatt levels, other nuclear reactor designs including: solid core, fluidized bed, and gaseous core, are considered.
Date: January 1, 1983
Creator: Angelo, J.J. & Buden, D.
Partner: UNT Libraries Government Documents Department

/sup 238/Pu processing at the Savannah River Plant

Description: /sup 238/Pu is produced by irradiating /sup 237/Np. The /sup 237/Np is produced as a byproduct when natural or enriched uranium is irradiated with neutrons. The /sup 237/Np is separated by solvent extraction and ion exchange. It is converted to NpO/sub 2/ and fabricated into targets for irradiation. The irradiated targets are cooled and dissolved in strong nitric acid. The /sup 238/Pu and /sup 237/Np are separated from fission products and other cationic impurities and from each other by three cycles of anion exchange. The /sup 237/Np is recycled to produce more targets for irradiation. The pure /sup 238/Pu solution is precipitated as Pu oxalate and calcined to PuO/sub 2/. After several powder-conditioning steps, the PuO/sub 2/ is hot pressed into fuel forms. Each form is encased in iridium for loading into a specially designed power unit for space application. 8 references, 9 figures, 1 table.
Date: January 1, 1983
Creator: Burney, G.A.
Partner: UNT Libraries Government Documents Department

A review of research programs related to the behavior of plutonium in the environment

Description: Plutonium-fueled radioisotopic heat sources find application in a spectrum of space, terrestrial, and underseas applications to generate electrical power by thermoelectric or dynamic-cycle conversion. Such systems under postulated accident conditions could release radioactivity into the environment resulting in risks to the general population. The released radioactivity could be dispersed into various environmental media, such as air, soil, and water and interact with people through various exposure pathways leading to inhalation, ingestion, and external radiological doses and associated health effects. The authors developed short-term exposure (RISK II) and long-term exposure (RISK III) models for use in safety risk assessments of space missions utilizing plutonium-fueled electric power systems. To effectively use these models in risk assessments, representative input values must be selected for a spectrum of environmental transfer parameters that characterize the behavior of plutonium in the environment. The selection of appropriate transfer parameters to be used in a given analysis will depend on the accident scenarios to be modeled and the terrestrial and aquatic environments to be encountered. The authors reviewed the availability of plutonium in the environment. This report summarizes the research programs presently being conducted at six Department of Energy Laboratories and makes recommendations on areas where further research is needed to fill gaps in the data necessary for risk assessments
Date: June 15, 1983
Creator: Bartram, Bart W. & Wilkinson, Martha J.
Partner: UNT Libraries Government Documents Department

Theories on plasma arc-drop in thermionic energy converters. Final report on thermionics energy conversion research analysis

Description: A summary of the theoretical developments of the problem of plasma arc-drop in thermionic energy converters carried out during 1976 to 1982 at Princeton University is presented. It reviews the basic formulation of the isothermal model which delineates the physical origin of the arc-drop, its order of magnitude and the possibilities of arc-drop reduction under one-dimensional, steady-state, ignited-mode operation, and also the generalization of the isothermal model to the non-isothermal model. The possibility of a heat-to-laser energy recombination laser using a thermionic diode operating in the unsteady mode is discussed. An analysis of the low-current regime with attentions focussed on the effects of ion reflections and trapped-ions effects in the emitter sheath is presented.
Date: March 1, 1983
Creator: Lam, S.H.
Partner: UNT Libraries Government Documents Department

Space reactors. Progress report, October 1981-March 1982

Description: Progress in design studies and technology for the SP-100 Project - successor to the Space Power Advanced Reactor (SPAR) Project - is reported for the period October 1, 1981 to March 31, 1982. The basis for selecting a high-temperature, UO/sub 2/-fueled, heat-pipe-cooled reactor with a thermoelectric conversion system as the 100-kW/sub e/ reference design has been reviewed. Although no change has been made in the general concept, design studies have been done to investigate various reactor/conversion system coupling methods and core design modifications. Thermal and mechanical finite element modeling and three-dimensional Monte Carlo analysis of a core with individual finned fuel elements are reported. Studies of unrestrained fuel irradiation data are discussed that are relevant both to the core modeling work and to the design and fabrication of the first in-pile irradiation test, which is also reported. Work on lithium-filled core heat pipe development is described, including the attainment of 15.6 kW/sub t/ operation at 1525 K for a 2-m-long heat pipe with a 15.7-mm outside diameter. The successful operation of a 5.5-m-long, lightweight potassium/titanium heat pipe at 760 K is described, and test results of a thermoelectric module with GaP-modified SiGe thermoelectric elements are presented.
Date: January 1, 1983
Creator: Ranken, W.A. (comp.)
Partner: UNT Libraries Government Documents Department

Space nuclear-safety program. Progress report, October 1982

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Special Nuclear Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues.
Date: March 1, 1983
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

Milliwatt-Generator Project. Progress report, October 1981-March 1982

Description: Los Alamos will fabricate the MC 3599 heat source (4.5 W) for the MC 3500 radioisotopic thermoelectric generator (RTG) in addition to the MC 2893A heat source (4.0 W) for the MC 2730A RTG. Progress on the following tasks is described in detail: /sup 238/Pu fuel processing and characterization, fabrication of test units, destructive testing, and quality assurance. (WHK)
Date: March 1, 1983
Creator: Maraman, W.J. (comp.)
Partner: UNT Libraries Government Documents Department

Space nuclear safety program. Progress report, December 1982

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Special Nuclear Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues.
Date: June 1, 1983
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

Grain-boundary cavitation and weld-underbead cracking in DOP-26 iridium alloy

Description: Plutonium-238 oxide fuel pellets for the General Purpose Heat Source Radioisotopic thermoelectric generators to be used on the NASA Galileo Mission to Jupiter and the International Solar Polar Mission are produced and encapsulated in DOP-26 iridium alloy at the Savannah River Plant. DOP-26 iridium alloy was developed at the Oak Ridge National Laboratory and contains nominally 0.3 weight-percent tungsten, 60-ppM thorium and 50-ppM aluminum. Underbead cracks occasionally occur in the girth weld on the iridium alloy cladding in the area where the gas tungsten arc is quenched. A variety of electron beam techniques have been used to determine the cause of cracking. Results are discussed. (WHK)
Date: January 1, 1983
Creator: Mosley, W.C. Jr.
Partner: UNT Libraries Government Documents Department

Long-term exposure of /sup 238/PuO/sub 2/ to a terrestrial environment. Volume 2

Description: Two environmental simulation chambers were used to study the behavior of a /sup 238/PuO/sub 2/ heat source deposited in a humid, temperate environment. Large fragments from an impact-tested source were deposited in the first chamber, and fines from the source were placed in the second. Plutonium released into the soil, the soil drainages, and the condensates from the dehumidifiers were monitored throughout the experiment. The concentration of plutonium released into the soil drainages increased with time, obeying an apparent exponential growth curve over the duration of the experiment (5.7 yr). The bulk of the released plutonium, up to 0.3% of the source, was retained in the soil. A simulated cleanup operation at the conclusion of the experiment, which included removal of the source and the top inch of soil, resulted in an increased rate of plutonium release into the soil drainage and essentially no observable change of release rate into the air. Large chunks of PuO/sub 2/ deposited in one of the chambers underwent spontaneous disintegration into smaller pieces; after 2 yr the deposited material could barely be distinguished from the fines deposited in the other chamber.
Date: September 1, 1983
Creator: Patterson, J.H.; Heaton, R.C.; Herrera, B.; Nelson, G.B. & Steinkruger, F.J.
Partner: UNT Libraries Government Documents Department

Plutonium-238 processing at Savannah River Plant

Description: Plutonium-238 is produced by irradiating NpO/sub 2/-Al cermet slugs or tubes with neutrons. The neptunium-237 is produced as a by-product when natural or enriched uranium is irradiated with neutrons. The neptunium is separated by solvent extraction and ion exchange and precipitated as neptunium oxalate. Neptunium oxalate is calcined to neptunium oxide and fabricated into targets for irradiation. The irradiation conditions are controlled to produce plutonium with 80 to 90 wt % /sup 238/Pu.
Date: January 1, 1983
Creator: Burney, G.A.
Partner: UNT Libraries Government Documents Department

Space nuclear-safety program, November 1982. Progress report

Description: This technical monthly report covers studies related to the use of /sup 238/PuO/sub 2/ in radioisotope power systems carried out for the Office of Special Nuclear Projects of the US Department of Energy by Los Alamos National Laboratory. Most of the studies discussed here are ongoing. Results and conclusions described may change as the work continues.
Date: May 1, 1983
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department