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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

Nuclear space power safety and facility guidelines study

Description: This report addresses safety guidelines for space nuclear reactor power missions and was prepared by The Johns Hopkins University Applied Physics Laboratory (JHU/APL) under a Department of Energy grant, DE-FG01-94NE32180 dated 27 September 1994. This grant was based on a proposal submitted by the JHU/APL in response to an {open_quotes}Invitation for Proposals Designed to Support Federal Agencies and Commercial Interests in Meeting Special Power and Propulsion Needs for Future Space Missions{close_quotes}. The United States has not launched a nuclear reactor since SNAP 10A in April 1965 although many Radioisotope Thermoelectric Generators (RTGs) have been launched. An RTG powered system is planned for launch as part of the Cassini mission to Saturn in 1997. Recently the Ballistic Missile Defense Office (BMDO) sponsored the Nuclear Electric Propulsion Space Test Program (NEPSTP) which was to demonstrate and evaluate the Russian-built TOPAZ II nuclear reactor as a power source in space. As of late 1993 the flight portion of this program was canceled but work to investigate the attributes of the reactor were continued but at a reduced level. While the future of space nuclear power systems is uncertain there are potential space missions which would require space nuclear power systems. The differences between space nuclear power systems and RTG devices are sufficient that safety and facility requirements warrant a review in the context of the unique features of a space nuclear reactor power system.
Date: September 11, 1995
Creator: Mehlman, W. F.
Partner: UNT Libraries Government Documents Department

Nuclear source term evaluation for launch accident environments

Description: When United States space missions involve launching vehicles carrying significant quantities of nuclear material, US law requires that prior to launch the mission be approved by the Office of the President. This approval is to be based on an evaluation of the nuclear safety risks associated with the mission and the projected benefits. To assist in the technical evaluation of risks for each mission, an Interagency Nuclear Safety Review Panel (INSRP) is instituted to provide an independent assessment of the mission risks. INSRP`s assessment begins with a review of the safety analysis for the mission completed by the organization proposing the mission and documented in a Safety Analysis Report (SAR). In addition, INSRP may execute other analyses it deems necessary. Results are documented and passed to the decision maker in a Safety Evaluation Report (SER). The INSRP review and evaluation process has been described in some detail in a number of papers.
Date: May 1, 1996
Creator: McCulloch, W.H.
Partner: UNT Libraries Government Documents Department

Heatpipe power system and heatpipe bimodal system design and development options

Description: The Heatpipe Power System (HPS) is a potential, near-term, low-cost space fission power system. The Heatpipe Bimodal System (HBS) is a potential, near-term, low-cost space fission power and/or propulsion system. Both systems will be composed of independent modules, and all components operate within the existing databases. The HPS and HBS have relatively few system integration issues; thus, the successful development of a module is a significant step toward verifying system feasibility and performance estimates. A prototypic HPS module is being fabricated, and testing is scheduled to begin in November 1996. A successful test will provide high confidence that the HPS can achieve its predicted performance.
Date: February 1, 1997
Creator: Houts, M.G.; Poston, D.I. & Emrich, W.J. Jr.
Partner: UNT Libraries Government Documents Department

Design of a nuclear-powered rover for lunar or Martian exploration

Description: To perform more advanced studies on the surface of the moon or Mars, a rover must provide long-term power ({ge}10 kW{sub e}). However, a majority of rovers in the past have been designed for much lower power levels (i.e., on the order of watts) or for shorter operating periods using stored power. Thus, more advanced systems are required to generate additional power. One possible design for a more highly powered rover involves using a nuclear reactor to supply energy to the rover and material from the surface of the moon or Mars to shield the electronics from high neutron fluxes and gamma doses. Typically, one of the main disadvantages of using a nuclear-powered rover is that the required shielding would be heavy and expensive to include as part of the payload on a mission. Obtaining most of the required shielding material from the surface of the moon or Mars would reduce the cost of the mission and still provide the necessary power. This paper describes the basic design of a rover that uses the Heatpipe Power System (HPS) as an energy source, including the shielding and reactor control issues associated with the design. It also discusses briefly the amount of power that can be produced by other power methods (solar/photovoltaic cells, radioisotope power supplies, dynamic radioisotope power systems, and the production of methane or acetylene fuel from the surface of Mars) as a comparison to the HPS.
Date: August 1, 1998
Creator: Trellue, H.R.; Trautner, R.; Houts, M.G.; Poston, D.I.; Giovig, K.; Baca, J.A. et al.
Partner: UNT Libraries Government Documents Department

RSMASS-D models: An improved method for estimating reactor and shield mass for space reactor applications

Description: Three relatively simple mathematical models have been developed to estimate minimum reactor and radiation shield masses for liquid-metal-cooled reactors (LMRs), in-core thermionic fuel element (TFE) reactors, and out-of-core thermionic reactors (OTRs). The approach was based on much of the methodology developed for the Reactor/Shield Mass (RSMASS) model. Like the original RSMASS models, the new RSMASS-derivative (RSMASS-D) models use a combination of simple equations derived from reactor physics and other fundamental considerations, along with tabulations of data from more detailed neutron and gamma transport theory computations. All three models vary basic design parameters within a range specified by the user to achieve a parameter choice that yields a minimum mass for the power level and operational time of interest. The impact of critical mass, fuel damage, and thermal limitations are accounted for to determine the required fuel mass. The effect of thermionic limitations are also taken into account for the thermionic reactor models. All major reactor component masses are estimated, as well as instrumentation and control (I&C), boom, and safety system masses. A new shield model was developed and incorporated into all three reactor concept models. The new shield model is more accurate and simpler to use than the approach used in the original RSMASS model. The estimated reactor and shield masses agree with the mass predictions from separate detailed calculations within 15 percent for all three models.
Date: October 1, 1997
Creator: Marshall, A.C.
Partner: UNT Libraries Government Documents Department

Conceptual design analysis of an MHD power conversion system for droplet-vapor core reactors. Final report

Description: A nuclear driven magnetohydrodynamic (MHD) generator system is proposed for the space nuclear applications of few hundreds of megawatts. The MHD generator is coupled to a vapor-droplet core reactor that delivers partially ionized fissioning plasma at temperatures in range of 3,000 to 4,000 K. A detailed MHD model is developed to analyze the basic electrodynamics phenomena and to perform the design analysis of the nuclear driven MHD generator. An incompressible quasi one dimensional model is also developed to perform parametric analyses.
Date: December 31, 1995
Creator: Anghaie, S. & Saraph, G.
Partner: UNT Libraries Government Documents Department

Terrestrial applications of the heatpipe power system

Description: A terrestrial reactor that uses the same design approach as the Heatpipe Power System (HPS) may have applications both on earth and on other planetary surfaces. The baseline HPS is a potential, near-term, low-cost space fission power system. The system will be composed of independent modules, and all components operate within the existing database. The HPS has relatively few system integration issues; thus, the successful development of a module is a significant step toward verifying system feasibility and performance estimates. A prototypic, refractory-metal HPS module is being fabricated, and testing is scheduled to begin in November 1996. A successful test will provide high confidence that the HPS can achieve its predicted performance. An HPS incorporating superalloys will be better suited for some terrestrial or planetary applications. Fabrication and testing of a superalloy HPS module should be less challenging than that of the refractory metal module. A superalloy HPS core capable of delivering > 100 kWt to a power conversion subsystem could be fabricated for about $500k (unfueled). Tests of the core with electric heat (used to simulate heat from fission) could demonstrate normal and off-normal operation of the core, including the effects of heatpipe failure. A power conversion system also could be coupled to the core to demonstrate full system operation.
Date: February 1, 1997
Creator: Houts, M.G. & Poston, D.I.
Partner: UNT Libraries Government Documents Department

Cylindrical TEMP optimization: Final report

Description: This report consists of vugraphs of a presentation on the thermoelectric-electromagnetic pump. Topics covered are: modeling methodology; summary of rectangular TEMP results; cylindrical TEMP optimization task; optimization approach; optimization results; discussion of cylindrical optimization; and thoughts on future work.
Date: July 12, 1988
Creator: Buksa, J.; McColl, D.; Williams, K. & Swenson, D.
Partner: UNT Libraries Government Documents Department

Engineering design aspects of the heat-pipe power system

Description: The Heat-pipe Power System (HPS) is a near-term, low-cost space power system designed at Los Alamos that can provide up to 1,000 kWt for many space nuclear applications. The design of the reactor is simple, modular, and adaptable. The basic design allows for the use of a variety of power conversion systems and reactor materials (including the fuel, clad, and heat pipes). This paper describes a project that was undertaken to develop a database supporting many engineering aspects of the HPS design. The specific tasks discussed in this paper are: the development of an HPS materials database, the creation of finite element models that will allow a wide variety of investigations, and the verification of past calculations.
Date: October 1, 1997
Creator: Capell, B.M.; Houts, M.G.; Poston, D.I. & Berte, M.
Partner: UNT Libraries Government Documents Department

Space reactor safety, 1985--1995 lessons learned

Description: Space reactor safety activities and decisions have evolved over the last decade. Important safety decisions have been made in the SP-100, Space Exploration Initiative, NEPSTP, SNTP, and Bimodal Space Reactor programs. In addition, international guidance on space reactor safety has been instituted. Space reactor safety decisions and practices have developed in the areas of inadvertent criticality, reentry, radiological release, orbital operation, programmatic, and policy. In general, the lessons learned point out the importance of carefully reviewing previous safety practices for appropriateness to space nuclear programs in general and to the specific mission under consideration.
Date: December 31, 1995
Creator: Marshall, A.C.
Partner: UNT Libraries Government Documents Department

HPS: A space fission power system suitable for near-term, low-cost lunar and planetary bases

Description: Near-term, low-cost space fission power systems can enhance the feasibility and utility of lunar and planetary bases. One such system, the Heatpipe Power System (HPS), is described in this paper. The HPS draws on 40 yr of United States and international experience to enable a system that can be developed in <5 yr at a cost of <$100M. Total HPS mass is <600 kg at 5 kWe and <2000 kg at 50 kWe, assuming that thermoelectric power conversion is used. More advanced power conversion systems could reduce system mass significantly. System mass for planetary surface systems also may be reduced (1) if indigenous material is used for radiation shielding and (2) because of the positive effect of the gravitational field on heatpipe operation. The HPS is virtually non-radioactive at launch and is passively subcritical during all credible launch accidents. Full-system electrically heated testing is possible, and a ground nuclear power test is not needed for flight qualification. Fuel burnup limits are not reached for several decades, thus giving the system long-life potential.
Date: May 1, 1996
Creator: Houts, M.G.; Poston, D.I. & Ranken, W.A.
Partner: UNT Libraries Government Documents Department

On-Orbit Asset Management System, September 1995. Final report

Description: Declining budgets have prompted the need to decrease launch cost, increase satellite lifetime, and accomplish more with each satellite. This study evaluates an OOAMS system for its ability to lengthen lifetime of on-orbit assets, decrease the number of satellites required to perform a mission, increase responsiveness, and provide increased mission capability/tactical advantage. Lifetime analysis suggest that the larger satellite systems (NASA and military communication systems, surveillance satellites and earth observing satellites) would benefit most from a nuclear bimodal OOAMS. Evaluation of satellite constellations indicate that a modest reduction in the number of satellites could be realized using OOAMS if the thermal restart capability was at least ten. An OOAMS could improve the responsiveness (launching of new assets) using on-orbit reconstitution of assets. A top level utility assessment was done to address system cost issues relating to funding profiles, first unit cost, and break-even analysis. From mission capture and orbital lifetime criteria, the recommended minimum orbital altitude is 900 km. The on-orbit thermal restart capability should be increased from five to ten. Analysis of total impulse vs propellant consumed for selected missions suggests that total impulse be increased from 40 million to 48 million Newton-seconds.
Date: October 10, 1995
Partner: UNT Libraries Government Documents Department

Low-mass, intrinsically-hard high-temperature radiator. Final report, Phase I

Description: Thermacore, Inc. of Lancaster, Pennsylvania has completed a Phase I SBIR program to investigate the use of layered ceramic/metal composites in the design of low-mass hardened radiators for space heat rejection systems. The program is being monitored by the Los Alamos National Laboratory (LANL) for the Strategic Defense Initiative Organization (SDIO). This effort evaluated the use of layered composites as a material to form thin-walled, vacuum leaktight heat pipes. The heat pipes would be incorporated into a large heat pipe radiator for waste heat rejection from a space nuclear power source. This approach forms an attractive alternative to metal or silicon-carbon fiber reinforced metal heat pipes by offering a combination of low mass and improved fabricability. Titanium has been shown to have a yield strength too low at 875{degrees}K to be a useful radiator material. A silicon carbide fiber reinforced titanium material appears to have sufficient strength at 875{degrees}K. but cannot be welded due to the continuous fibers, and the preferred heat pipe working fluid (potassium) has been demonstrated to be incompatible with silicon carbide at 875{degrees}K. Moreover, titanium does not appear to be acceptable for radiators subjected to anticipated laser threats. As part of this effort, Thermacore performed composite material evaluations on combinations of refractory metals and ceramic powders. Layered composite tube samples with wall thicknesses as thin as 0.012 inches were developed. Fabrication experiments were performed that demonstrated the weldability of layered composites. Two titanium/titanium diboride composite tubes were successfully fabricated into potassium heat pipes and operated at temperatures in excess of 700{degrees}C. A hybrid composite tube was also fabricated into a potassium heat pipe. The tube was composed of alternating layers of niobium-1% zirconium foil and layers of a mixture of titanium powder and titanium diboride powder.
Date: June 15, 1990
Partner: UNT Libraries Government Documents Department

Development of a Robust Tri-Carbide Fueled Reactor for Multimegawatt Space Power and Propulsion Applications

Description: An innovative reactor core design based on advanced, mixed carbide fuels was analyzed for nuclear space power applications. Solid solution, mixed carbide fuels such as (U,Zr,Nb)c and (U,Zr, Ta)C offer great promise as an advanced high temperature fuel for space power reactors.
Date: August 11, 2004
Creator: Anghaie, Samim; Knight, Travis W.; Plancher, Johann & Gouw, Reza
Partner: UNT Libraries Government Documents Department

SP-100 low mass shield design

Description: The shielding considerations for an unmanned space reactor system are somewhat different from those for a terrestrial reactor. An unmanned operation in space implies that only a shadow shield, rather than a 4..pi.. one, is required to protect payload hardware that typically can tolerate 10/sup 4/ to 10/sup 6/ times more radiation than can a human crew. On the other hand, the system mass, of which the radiation shield can be a significant fraction, is a severe constraint for space reactors and not normally a problem with terrestrial ones. The object of this paper is to briefly summarize advancements made on various aspects of low mass shield design for space reactors, including materials and their arrangements, geometric factors and their potential impact on system design optimization, and proposed new configuration concepts for further mass reduction.
Date: January 1, 1985
Creator: Carlson, D.E.
Partner: UNT Libraries Government Documents Department

Selection of power plant elements for future space electric power systems

Description: A study on the type of nuclear reactor power plants that should be developed for future space missions is described. After careful consideration of power plant configuration weights, sizes, reliabilities, safety, development cost and time, the configuration selected to be pursued was a heat-pipe reactor design with thermoelectric converters and heat-pipe radiator.
Date: January 1, 1979
Creator: Buden, D.
Partner: UNT Libraries Government Documents Department

100-kW/sub e/ Nuclear space electric power source

Description: The current 100-kW/sub e/ space nuclear power technology program could provide an electric power source for nuclear electric propulsion. The power plant is relatively compact, light weight, and has the advantages of long life and immunity to degradation while passing through the Van Allen belts. The reactor is a unique design using heat pipes to transfer heat from the reactor core to the thermoelectric converters. The converters are an improved design over those used in the radioisotope space program. The radiator, used to eliminate waste heat to space, also makes use of heat pipes. All single failure points have been eliminated from the power plant design and redundancies are provided to ensure high reliability. The power plant configuration and some key results of the current component experimental program are discussed.
Date: January 1, 1979
Creator: Buden, D.
Partner: UNT Libraries Government Documents Department

Missions and planning for nuclear space power

Description: Requirements for electrical and propulsion power for space are expected to increase dramatically in the 1980s. Nuclear power is probably the only source for some deep space missions and a major competitor for many orbital missions, especially those at geosynchronous orbit. Because of the potential requirements, a technology program on reactor components has been initiated by the Department of Energy. The missions that are foreseen, the current reactor concept, and the technology program plan are described.
Date: January 1, 1979
Creator: Buden, D.
Partner: UNT Libraries Government Documents Department

A 50-100 kWe gas-cooled reactor for use on Mars.

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 reactor's thermal characteristics, feasibility for use in an extraterrestrial environment, and the reactor's 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.
Date: April 1, 2006
Creator: Peters, Curtis D. (.)
Partner: UNT Libraries Government Documents Department

ZrH-reactor-technology program. Progress report, April-June 1974

Description: The report on the 2 kW(e) reactor-organic Rankine system was drafted. This report details the design parameters of a minimum weight, 2 kW(e) reactor-organic Rankine system. The system is designed for 5 years unattended life in space. The reactor produces 16.2 kW of thermal power with a NaK outlet temperature of 800/sup 0/F and a 200/sup 0/F ..delta..T. The reactor contains 19 fuel elements, 1.25'' in diameter by 10'' long, hydrided to an N/sub H/ of 6.35. The terrestrial applications effort was oriented towards the establishment of the feasibility of utilizing the zirconium hydride reactor technology in a subsea application for supplying electrical power to deep water, and other environmentally severe, oil well installations. The overall system concept is shown. The power system is composed of three basic modules (i.e., a reactor module, a generator module, and a heat rejection system) mounted on a barge. The barge is then towed to the installation site and submerged to mate with a previously installed seafloor foundation. An assembly/disassembly sequence was drafted detailing the steps required to assemble the reactor module and to disassemble it after 4 years of operations.
Date: July 12, 1974
Partner: UNT Libraries Government Documents Department