Gas-cooled Reactor Power Systems for Space


Book Description

In this paper the characteristics of six designs for power levels of 2, 10, and 20 MWe for operating times of 1 and 7 y are described. The operating conditions for these arbitrary designs were chosen to minimize system specific mass. The designs are based on recent work which benefits from earlier analyses of nuclear space power systems conducted at our Laboratory. Both gas- and liquid-cooled reactors had been considered. Pitts and Walter (1970) reported on the results of a detailed study of a 10-MWe lithium-cooled reactor in a potassium Rankine system. Unpublished results (1966) of a computer analysis provide details of an argon-cooled reactor in an argon Brayton system. The gas-cooled reactor design was based on extensive development work on the 500-MWth reactor for the nuclear ramjet (Pluto) as described by Walter (1964). The designs discussed here draw heavily on the Pluto project experience, which culminated in a successful full-power ground test as reported by Reynolds (1964). At higher power levels gas-cooled reactors coupled with Brayton systems with advanced radiator designs become attractive.




The Space Nuclear Reactor Program


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Gas-cooled Reactor for Space Power Systems


Book 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.




Fiscal year 1988 Department of Energy authorization


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Summary of Space Nuclear Reactor Power Systems, 1983--1992


Book Description

This report summarizes major developments in the last ten years which have greatly expanded the space nuclear reactor power systems technology base. In the SP-100 program, after a competition between liquid-metal, gas-cooled, thermionic, and heat pipe reactors integrated with various combinations of thermoelectric thermionic, Brayton, Rankine, and Stirling energy conversion systems, three concepts:were selected for further evaluation. In 1985, the high-temperature (1,350 K), lithium-cooled reactor with thermoelectric conversion was selected for full scale development. Since then, significant progress has been achieved including the demonstration of a 7-y-life uranium nitride fuel pin. Progress on the lithium-cooled reactor with thermoelectrics has progressed from a concept, through a generic flight system design, to the design, development, and testing of specific components. Meanwhile, the USSR in 1987--88 orbited a new generation of nuclear power systems beyond the, thermoelectric plants on the RORSAT satellites. The US has continued to advance its own thermionic fuel element development, concentrating on a multicell fuel element configuration. Experimental work has demonstrated a single cell operating time of about 1 1/2-y. Technology advances have also been made in the Stirling engine; an advanced engine that operates at 1,050 K is ready for testing. Additional concepts have been studied and experiments have been performed on a variety of systems to meet changing needs; such as powers of tens-to-hundreds of megawatts and highly survivable systems of tens-of-kilowatts power.




High Temperature Gas-cooled Reactors


Book Description

High-Temperature Gas Reactors is the fifth volume in the JSME Series on Thermal and Nuclear Power Generation. Series Editor Yasuo Koizumi and his Volume editors Tetsuaki Takeda and Yoshiyuki Inagaki present the latest research on High-Temperature Gas Reactor (HTGR) development and utilization, beginning with an analysis of the history of HTGRs. A detailed analysis of HTGR design features, including reactor core design, cooling tower design, pressure vessel design, I&C factors and safety design, provides readers with a solid understanding of how to develop efficient and safe HTGR within a nuclear power plant. The authors combine their knowledge to present a guide on the safety of HTGRs throughout the entire reactor system, drawing on their unique experience to pass on lessons learned and best practices to support professionals and researchers in their design and operation of these advanced reactor types. Case studies of critical testing carried out by the authors provide the reader with firsthand information on how to conduct tests safely and effectively and an understanding of which responses are required in unexpected incidents to achieve their research objectives. An analysis of technologies and systems in development and testing stages offer the reader a look to the future of HTGRs and help to direct and inform their further research in heat transfer, fluid-dynamics, fuel options and advanced reactor facility selection. This volume is of interest for nuclear and thermal energy engineers and researchers focusing on HTGRs, HTGR plant designers and operators, regulators, post graduate students of nuclear engineering, national labs, government officials and agencies in power and energy policy and regulations. Written by the leaders and pioneers in nuclear research at the Japanese Society of Mechanical Engineers and draws upon their combined wealth of knowledge and experience Includes real examples and case studies from Japan, the US and Europe to provide a deeper learning opportunity with practical benefits Considers the societal impact and sustainability concerns and goals throughout the discussion Includes safety factors and considerations, as well as unique results from performance testing of HTGR systems.




A 50-100 KWe Gas-cooled Reactor for Use on Mars


Book Description

"In the space exploration field there is a general consensus that nuclear reactor powered systems will be extremely desirable for future missions to the outer solar system. Solar systems suffer from the decreasing intensity of solar radiation and relatively low power density. Radioisotope Thermoelectric Generators are limited to generating a few kilowatts electric (kWe). Chemical systems are short-lived due to prodigious fuel use. A well designed 50-100 kWe nuclear reactor power system would provide sufficient power for a variety of long term missions. This thesis will present basic work done on a 50-100 kWe reactor power system that has a reasonable lifespan and would function in an extraterrestrial environment. The system will use a Gas-Cooled Reactor that is directly coupled to a Closed Brayton Cycle (GCR-CBC) power system. Also included will be some variations on the primary design and their effects on the characteristics of the primary design. This thesis also presents a variety of neutronics related calculations, an examination of the reactors thermal characteristics, feasibility for use in an extraterrestrial environment, and the reactors safety characteristics in several accident scenarios. While there has been past work for space reactors, the challenges introduced by thin atmospheres like those on Mars have rarely been considered."--P. iii.




The SP-100 Space Reactor Power System Program


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Megawatt Class Nuclear Space Power Systems (McNsps) Conceptual Design and Evaluation Report. Volume 1


Book Description

The objective was to determine which reactor, conversion, and radiator technologies would best fulfill future Megawatt Class Nuclear Space Power System Requirements. Specifically, the requirement was 10 megawatts for 5 years of full power operation and 10 years systems life on orbit. A variety of liquid metal and gas cooled reactors, static and dynamic conversion systems, and passive and dynamic radiators were considered. Four concepts were selected for more detailed study. The concepts are: a gas cooled reactor with closed cycle Brayton turbine-alternator conversion with heat pipe and pumped tube-fin heat rejection; a lithium cooled reactor with a free piston Stirling engine-linear alternator and a pumped tube-fin radiator; a lithium cooled reactor with potassium Rankine turbine-alternator and heat pipe radiator; and a lithium cooled incore thermionic static conversion reactor with a heat pipe radiator. The systems recommended for further development to meet a 10 megawatt long life requirement are the lithium cooled reactor with the K-Rankine conversion and heat pipe radiator, and the lithium cooled incore thermionic reactor with heat pipe radiator. Wetch, J. R. Unspecified Center NAS3-23867; RTOP 586-01-11...




Megawatt Class Nuclear Space Power Systems (McNsps) Conceptual Design and Evaluation Report. Volume 4


Book Description

A study was conducted by NASA Lewis Research Center for the Triagency SP-100 program office. The objective was to determine which reactor, conversion and radiator technologies would best fulfill future Megawatt Class Nuclear Space Power System Requirements. The requirement was 10 megawatts for 5 years of full power operation and 10 years system life on orbit. A variety of liquid metal and gas cooled reactors, static and dynamic conversion systems, and passive and dynamic radiators were considered. Four concepts were selected for more detailed study: (1) a gas cooled reactor with closed cycle Brayton turbine-alternator conversion with heatpipe and pumped tube fin rejection, (2) a Lithium cooled reactor with a free piston Stirling engine-linear alternator and a pumped tube-fin radiator, (3) a Lithium cooled reactor with a Potassium Rankine turbine-alternator and heat pipe radiator, and (4) a Lithium cooled incore thermionic static conversion reactor with a heat pipe radiator. The systems recommended for further development to meet a 10 megawatt long life requirement are the Lithium cooled reactor with the K-Rankine conversion and heat pipe radiator, and the Lithium cooled incore thermionic reactor with heat pipe radiator. Wetch, J. R. Unspecified Center BRAYTON CYCLE; ENERGY CONVERSION; HEAT PIPES; HEAT RADIATORS; LITHIUM COMPOUNDS; RANKINE CYCLE; REACTOR DESIGN; SPACE POWER REACTORS; STIRLING ENGINES; ELECTRIC POWER SUPPLIES; EQUIPMENT SPECIFICATIONS; SYSTEMS ENGINEERING..