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Assessment of energy storage concepts for use in pulsed space power systems

Description: Preliminary assessments have been completed for thermal energy storage in heat rejection systems as well as for regenerable electrical storage modules in systems having nuclear sources with Rankine power conversion and solar sources with Brayton and Rankine power conversion. Storage technologies considered for the regenerable modules include flywheels, batteries, fuel cells, superconducting magnets and capacitors. Both source and sink thermal storage were examined for the solar energy based systems. Benefits derived from incorporating thermal storage in the heat rejection system depend on the storage density and the radiator specific mass. The analysis shows that inclusion of a thermal store results in heat rejection system mass reductions for generation times of up to 1100 seconds. Results show that the storage system value (mass reduction) increases with decreasing total generation time. In general, the value is greatest for generation times of 600 seconds or less although mass savings are realized for generation times nearly twice as long. For a total generation time of 500 seconds, incorporating storage in a nuclear Rankine power system results in a mass reduction of 50%. System masses similar to the nuclear Rankine are obtainable for solar Rankine and Brayton cycles using regenerable electrical storage modules. However, a 100-orbit recharge time is required, when the constraint of keeping concentrator areas smaller than 1000 m/sup 2/ is also imposed.
Date: January 1, 1987
Creator: Olszewski, M. & Morris, D.G.
Partner: UNT Libraries Government Documents Department

Evaluation of molybdenum and its alloys. [Reactor core heat pipes]

Description: The choice of pure molybdenum as the prime candidate material for space reactor core heat pipes is critically examined. Pure molybdenum's high ductile-brittle transition temperature appears to be its major disadvantage. The candidate materials examined in detail for this application include low carbon arc-cast molybdenum, TZM-molybdenum alloy, and molybdenum-rhenium alloys. Published engineering properties are collected and compared, and it appears that Mo-Re alloys with 10 to 15% rhenium offer the best combination. Hardware is presently being made from electron beam melted Mo-13Re to test this conclusion.
Date: January 1, 1981
Creator: Lundberg, L.B.
Partner: UNT Libraries Government Documents Department

Gas-cooled reactor for space power systems

Description: Reactor characteristics based on extensive development work on the 500-MWt reactor for the Pluto nuclear ramjet are described for space power systems useful in the range of 2 to 20 MWe for operating times of 1 y. The modest pressure drop through the prismatic ceramic core is supported at the outlet end by a ceramic dome which also serves as a neutron reflector. Three core materials are considered which are useful at temperatures up to about 2000 K. Most of the calculations are based on a beryllium oxide with uranium dioxide core. Reactor control is accomplished by use of a burnable poison, a variable-leakage reflector, and internal control rods. Reactivity swings of 20% are obtained with a dozen internal boron-10 rods for the size cores studied. Criticality calculations were performed using the ALICE Monte Carlo code. The inherent high-temperature capability of the reactor design removes the reactor as a limiting condition on system performance. The low fuel inventories required, particularly for beryllium oxide reactors, make space power systems based on gas-cooled near-thermal reactors a lesser safeguard risk than those based on fast reactors.
Date: May 1, 1987
Creator: Walter, C.E. & Pearson, J.S.
Partner: UNT Libraries Government Documents Department

An alternative strategy for low specific power reactors to power interplanetary spacecraft, based on exploiting lasers and lunar resources

Description: A key requirement setting the minimum electric propulsion performance (specific power ..cap alpha../sub e/ = kW/sub e//kg) for manned missions to Mars is the maximum allowable radiation dose to the crew during the long transits between Earth and Mars. Penetrating galactic cosmic rays and secondary neutron showers give about 0.1-rem/day dose, which only massive shielding (e.g., a meter of concrete) can reduce significantly. With a humane allowance for cabin space, the shielding mass becomes so large that it prohibitively escalates the propellant consumption required for reasonable trip times. This paper covers various proposed methods for using reactor power to propel spacecraft. 7 refs., 6 figs., 1 tab.
Date: February 2, 1989
Creator: Logan, B.G.
Partner: UNT Libraries Government Documents Department

Fission fragment rockets: A new frontier

Description: A new reactor concept is described which would enable fission fragments to be continuously extracted from the reactor. Such a reactor has the potential of enabling extremely energetic and ambitious deep space missions. In this talk the basic physics issues involved in the operation of this type of reactor are outlined, and some possible applications to space exploration are described. 3 refs., 2 figs., 3 tabs.
Date: April 1, 1989
Creator: Chapline, G.F.; Howard, W.M. & Schnitzler, B.G.
Partner: UNT Libraries Government Documents Department

Space Nuclear Safety Program. Progress report, May 1984

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. Covered are: general-purpose heat source testing, light-weight radioisotope heater unit, and iridium biaxial testing.
Date: September 1, 1985
Creator: George, T.G. (comp.)
Partner: UNT Libraries Government Documents Department

Particle Bed Reactor scaling relationships

Description: Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result in a wide range of reactor weights and performance. Extremely light weight reactors (approximately 1 kg/MW) are possible with the appropriate choice of moderator/reflector and power density. Such systems are very attractive for propulsion systems where parasitic weight has to be minimized.
Date: January 1, 1987
Creator: Slovik, G.; Araj, K.; Horn, F.L.; Ludewig, H. & Benenati, R.
Partner: UNT Libraries Government Documents Department

Postirradiation examination results from SP-1

Description: This paper describes the postirradiation examination results from several of the fuel pins irradiated in the SP-1 test. The SP-1 test is the first of two tests irradiated in EBR-II to be examined. These tests are designed to provide a direct comparison of the performance potential of UO/sub 2/ and UN fuel pins under conditions anticipated for the SP-100 reactor. In addition, these tests examine various feasibility issues associated with each fuel system. These issues include: the high temperature swelling behavior of uranium nitride fuel, fuel-cladding compatibility and the potential for UO/sub 2//Li reactions by oxygen diffusion through the cladding.
Date: January 1, 1986
Creator: Karnesky, R.A. & Mason, R.E.
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

Application of microfabrication technology to thermionic energy conversion. Progress report No. 5, August 1, 1980-October 31, 1980

Description: Considerable effort was directed toward the fabrication of a micron-spaced thermionic converter. In the process, a new technique has evolved which appears more promising and has been investigated theoretically. In both techniques, electrodes of similar differential thermal expansions are utilized to prevent shear stresses from disrupting the spacing pillars. The newer technique has additional advantages that simplify the fabrication of the diode structure, thus making it more practical. Progress is described.
Date: November 14, 1980
Creator: Brodie, I. & Shepherd, C.
Partner: UNT Libraries Government Documents Department

Nuclear-powered satellite studies. Final report, October 1, 1978-March 31, 1980

Description: Progress achieved during the period October 1, 1978 to March 31, 1980, on US DOE Contract No. DE-AC02-76ET33013.M003 is reported. Discussions of several pertinent aspects are included, e.g., schedule, personnel, and technology developments. The reporting period represents the final 18 months of activities of a project which was designed to provide continuing support in the area of nuclear space power technology. Important results have been obtained and communicated to the scientific community via publications and presentations. Project personnel have participated in point design efforts, a NASA Space Power Committee, and periodically provided support to Department of Energy activities as the need arose. This final report is intended to summarize activities over the life of the project.
Date: March 1, 1981
Creator: Kaplan, M.H.
Partner: UNT Libraries Government Documents Department

Safety program considerations for space nuclear reactor systems

Description: This report discusses the necessity for in-depth safety program planning for space nuclear reactor systems. The objectives of the safety program and a proposed task structure is presented for meeting those objectives. A proposed working relationship between the design and independent safety groups is suggested. Examples of safety-related design philosophies are given.
Date: August 1, 1984
Creator: Cropp, L.O.
Partner: UNT Libraries Government Documents Department

The role of integral experiments and nuclear cross section evaluations in space nuclear reactor design

Description: The importance of the nuclear and neutronic properties of candidate space reactor materials to the design process has been acknowledged as has been the use of benchmark reactor physics experiments to verify and qualify analytical tools used in design, safety, and performance evaluation. Since June 1966, the Cross Section Evaluation Working Group (CSEWG) has acted as an interagency forum for the assessment and evaluation of nuclear reaction data used in the nuclear design process. CSEWG data testing has involved the specification and calculation of benchmark experiments which are used widely for commercial reactor design and safety analysis. These benchmark experiments preceded the issuance oflthe industry standards for acceptance, but the benchmarks exceed the minimum acceptance criteria for such data. Thus, a starting place has been provided in assuring the accuracy and uncertainty of nuclear data important to space reactor applications. (FI)
Date: January 1, 1987
Creator: Moses, D.L. & McKnight, R.D.
Partner: UNT Libraries Government Documents Department

General-Purpose Heat Source Safety Verification Test program: Edge-on flyer plate tests

Description: The radioisotope thermoelectric generator (RTG) that will supply power for the Galileo and Ulysses space missions contains 18 General-Purpose Heat Source (GPHS) modules. The GPHS modules provide power by transmitting the heat of STYPu -decay to an array of thermoelectric elements. Each module contains four STYPuO2-fueled clads and generates 250 W(t). Because the possibility of a launch vehicle explosion always exists, and because such an explosion could generate a field of high-energy fragments, the fueled clads within each GPHS module must survive fragment impact. The edge-on flyer plate tests were included in the Safety Verification Test series to provide information on the module/clad response to the impact of high-energy plate fragments. The test results indicate that the edge-on impact of a 3.2-mm-thick, aluminum-alloy (2219-T87) plate traveling at 915 m/s causes the complete release of fuel from capsules contained within a bare GPHS module, and that the threshold velocity sufficient to cause the breach of a bare, simulant-fueled clad impacted by a 3.5-mm-thick, aluminum-alloy (5052-T0) plate is approximately 140 m/s.
Date: March 1, 1987
Creator: George, T.G.
Partner: UNT Libraries Government Documents Department

Progress on resolution of major surety issues. [Safety, environmental protection, safeguards, reliability, quality assurance]

Description: This paper presents a summary of the major surety issues (safety, environmental protection, sageguards, reliability, quality assurance) that have been identified during Phase I of the SP-100 Program and the progress that has been made in analyzing the most important of these issues in the context of the conceptual design effort. These issues have been identified as inadvertent criticality, toxic material release and dispersion, radiation exposure following end-of-life reentry, potential diversion of special nuclear material, failure to achieve end-of-life neutronic shutdown, and structural predictability for end-of-life re-entry or boost. Because of the complexity of these issues, a simplified conservative approach was taken during Phase I. Progress on these issues has been mainly in the area of increased understanding of the issues, identification of design features to resolve the issues, and quantitative evaluations of the surety characteristics of the various design concepts.
Date: January 1, 1985
Creator: Bell, C.R. & Boudreau, J.M.
Partner: UNT Libraries Government Documents Department

Evolution of a test article handling system for the SP-100 ground engineering system test

Description: A simulated space environment test of a flight prototypic SP-100 reactor, control system, and flight shield will be conducted at the Hanford Engineering Development Laboratory (HEDL). The flight prototypic components and the supporting primary heat removal system are collectively known as the Nuclear Assembly Test Article (TA). The unique configuration and materials of fabrication for the Test Article require a specialized handling facility to support installation, maintenance, and final disposal operations. Westinghouse Hanford Company, the Test Site Operator, working in conjunction with General Electric Company, the Test Article supplier, developed and evaluated several handling concepts resulting in the selection of a reference Test Article Handling System. The development of the reference concept for the handling system is presented.
Date: April 1, 1987
Creator: Shen, E.J.; Schweiger, L.J.; Miller, W.C.; Gluck, R. & Devies, S.M.
Partner: UNT Libraries Government Documents Department

Performance of refractory alloy-clad fuel pins

Description: This paper discusses objectives and basic design of two fuel-cladding tests being conducted in support of SP-100 technology development. Two of the current space nuclear power concepts use conventional pin type designs, where a coolant removes the heat from the core and transports it to an out-of-core energy conversion system. An extensive irradiation testing program was conducted in the 1950's and 1960's to develop fuel pins for space nuclear reactors. The program emphasized refractory metal clad uranium nitride (UN), uranium carbide (UC), uranium oxide (UO/sub 2/), and metal matrix fuels (UCZr and BeO-UO/sub 2/). Based on this earlier work, studies presented here show that UN and UO/sub 2/ fuels in conjunction with several refractory metal cladding materials demonstrated high potential for meeting space reactor requirements and that UC could serve as an alternative but higher risk fuel.
Date: December 1, 1984
Creator: Dutt, D.S.; Cox, C.M. & Millhollen, M.K.
Partner: UNT Libraries Government Documents Department

Instrumentation and Controls evaluation for space nuclear power systems

Description: Design of control and protection systems should be coordinated with the design of the neutronic, thermal-hydraulic, and mechanical aspects of the core and plant at the earliest possible stage of concept development. An integrated systematic design approach is necessary to prevent uncoordinated choices in one technology area from imposing impractical or impossible requirements in another. Significant development and qualification will be required for virtually every aspect of reactor control and instrumentation. In-core instrumentation widely used in commercial light water reactors will not likely be usable in the higher temperatures of a space power plant. Thermocouples for temperature measurement and gamma thermometers for flux measurement appear to be the only viable candidates. Recent developments in ex-core neutron detectors may provide achievable alternatives to in-core measurements. Reliable electronic equipment and high-temperature actuators will require major development efforts.
Date: January 1, 1984
Creator: Anderson, J.L. & Oakes, L.C.
Partner: UNT Libraries Government Documents Department

Interaction of the control system with core nuclear design for fast spectrum space power reactors

Description: Generic features of the interaction between core nuclear and mechanical designs and reactor control system design for compact fast spectrum space power reactors have been examined. Reactivity worths of various control concepts were evaluated for representative fast spectrum cores. In addition, special characteristics of each control concept that significantly affect core nuclear and mechanical design were considered. Ex-core control methods based on reflector control and in-core control devices such as control rods lead to divergent core designs and to different types of design problems. Total control worth of ex-core control devices is limited and is strongly dependent on core size. Reflector control also results in unfavorable radial power shifts, but ex-core control does avoid unnecessary reactor vessel penetrations. Control rods have characteristics essentially opposite to those of ex-core devices. Design demands on the primary control system are shown to be reduced by including a slow-acting secondary system based on in-core dispersed poison.
Date: January 1, 1987
Creator: Lell, R.M. & Hanan, N.A.
Partner: UNT Libraries Government Documents Department

Flight-systems safety program, September 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 Space 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: February 1, 1983
Creator: Bronisz, S.E. (comp.)
Partner: UNT Libraries Government Documents Department

SP-100 Test Site

Description: Preparatory activities are well under way at Hanford to convert the 309 Containment Building and its associated service wing to a 2.5 MWt nuclear test facility for the SP-100 Ground Engineering System (GES) test. Preliminary design is complete, encompassing facility modifications, a secondary heat transport system, a large vacuum system to enclose the high temperature reactor, a test assembly cell and handling system, control and data processing systems, and safety and auxiliary systems. The design makes extensive use of existing equipment to minimize technical risk and cost. Refurbishment of this equipment is 75% complete. The facility has been cleared of obstructing equipment from its earlier reactor test. Current activities are focusing on definitive design and preparation of the Preliminary Safety Analysis Report (PSAR) aimed at procurement and construction approvals and schedules to achieve reactor criticality by January 1992. 6 refs.
Date: January 1, 1988
Creator: Cox, C.M.; Mahaffey, M.K. & Miller, W.C.
Partner: UNT Libraries Government Documents Department

Strontium-90 fluoride data sheet

Description: This report is a compilation of available data and appropriate literature references on the properties of strontium-90 fluoride and nonradioactive strontium fluoride. The objective of the document is to compile in a single source pertinent data to assist potential users in the development, licensing, and use of /sup 90/SrF/sub 2/-fueled radioisotope heat sources for terrestrial power conversion and thermal applications. The report is an update of the Strontium-90 Fluoride Data Sheet (BNWL-2284) originally issued in April 1977.
Date: June 1, 1981
Creator: Fullam, H.T.
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

General-Purpose Heat Source Safety Verification Test series: SVT-7 through SVT-10

Description: The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will supply power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of /sup 238/PuO/sub 2/ ..cap alpha..-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first report (covering SVT-1 through SVT-6) described the results of flat and side-on module impacts. This report describes module impacts at angles of 15/sup 0/ and 30/sup 0/.
Date: September 1, 1985
Creator: George, T.G. & Pavone, D.
Partner: UNT Libraries Government Documents Department