WorldWideScience

Sample records for 10a space nuclear

  1. NaK flow control by electromagnetic pump of the SNAP-10A space nuclear reactor

    In the Institute for Advanced Studies (IEAv), were developed, successfully, the first two direct current electromagnetic pumps (DC EM pumps) of Brazil. The first was built with C-type magnet and coils; and the second, with Samarium-Cobalt permanent magnets, for magnetic field generation. Both were tested and performed quite satisfactory. The electromagnetic pump uses the Faraday principle, in which the interaction of the magnetic field and electric current generates the magneto-motive force, which produces the circulation of the fluid. This type of equipment may be used for controlling the liquid metal flow in nuclear space fast reactors. This paper shows the computer programs developed for design and evaluation of DC EM and electromagnetic thermoelectric (EMTE) pumps, the DC EM pump of Samarium-Cobalt magnets data to Mercury loop flow control, the EMTE pump of SNAP space nuclear reactor. It also compares the theoretical results to experimental data of NaK primary loop flow control by electromagnetic thermoelectric pump of the SNAP-10A space nuclear reactor, with satisfactory results, confirming the viability of the electromagnetic pumps evaluation scheme. (author)

  2. Nuclear power in space

    The development of space nuclear power and propulsion in the United States started in 1955 with the initiation of the ROVER project. The first step in the ROVER program was the KIWI project that included the development and testing of 8 non-flyable ultrahigh temperature nuclear test reactors during 1955-1964. The KIWI project was precursor to the PHOEBUS carbon-based fuel reactor project that resulted in ground testing of three high power reactors during 1965-1968 with the last reactor operated at 4,100 MW. During the same time period a parallel program was pursued to develop a nuclear thermal rocket based on cermet fuel technology. The third component of the ROVER program was the Nuclear Engine for Rocket Vehicle Applications (NERVA) that was initiated in 1961 with the primary goal of designing the first generation of nuclear rocket engine based on the KIWI project experience. The fourth component of the ROVER program was the Reactor In-Flight Test (RIFT) project that was intended to design, fabricate, and flight test a NERVA powered upper stage engine for the Saturn-class lunch vehicle. During the ROVER program era, the Unites States ventured in a comprehensive space nuclear program that included design and testing of several compact reactors and space suitable power conversion systems, and the development of a few light weight heat rejection systems. Contrary to its sister ROVER program, the space nuclear power program resulted in the first ever deployment and in-space operation of the nuclear powered SNAP-10A in 1965. The USSR space nuclear program started in early 70's and resulted in deployment of two 6 kWe TOPAZ reactors into space and ground testing of the prototype of a relatively small nuclear rocket engine in 1984. The US ambition for the development and deployment of space nuclear powered systems was resurrected in mid 1980's and intermittently continued to date with the initiation of several research programs that included the SP-100, Space Exploration

  3. SNAP Nuclear Space Reactors

    Corliss, William R

    1966-01-01

    This booklet describes the principles of nuclear-reactor space power plants and shows how they will contribute to the exploration and use of space. It compares them with chemical fuels, solar cells, and systems using energy from radioisotopes. The SNAP (Systems for Nuclear Auxiliary Power) Program, begun in 1955, is described.

  4. Nuclear Power in Space

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  5. Space nuclear power systems

    Materials of the 19-th Symposium on Space Nuclear Energetic and Engine Units taking place in 2002, in Albuquerque, USA are reviewed. Reports on transformation of heat energy produced by nuclear reactors in electrical one are presented in the reports. Result of works on improvement as traditional (Brayton and Rankine cycles, thermoelectricity and thermionic emission), so innovation converter systems (Stirling engine, alkali metal thermal to electric converter - AMTEC, thermoacoustic engine) are represented

  6. Space technology needs nuclear power

    Space technology needs nuclear power to solve its future problems. Manned space flight to Mars is hardly feasible without nuclear propulsion, and orbital nuclear power lants will be necessary to supply power to large satellites or large space stations. Nuclear power also needs space technology. A nuclear power plant sited on the moon is not going to upset anybody, because of the high natural background radiation level existing there, and could contribute to terrestrial power supply. (orig./HP)

  7. Space flight requires nuclear energy

    To be able to solve its future tasks, space flight needs nuclear energy: manned space flight to the Mars is almost unthinkable without nuclear propulsion, and orbital nuclear power plants will be required for the power supply of high-capacity satellites or large space stations. Nuclear energy needs space flight: a nuclear power plant on the moon does not bother man because of the high natural radiation exposure existing there, and could contribute to terrestrial power supply. (orig./HSCH)

  8. Nuclear Propulsion for Space Applications

    Houts, M. G.; Bechtel, R. D.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2013-01-01

    Basics of Nuclear Systems: Long history of use on Apollo and space science missions. 44 RTGs and hundreds of RHUs launched by U.S. during past 4 decades. Heat produced from natural alpha (a) particle decay of Plutonium (Pu-238). Used for both thermal management and electricity production. Used terrestrially for over 65 years. Fissioning 1 kg of uranium yields as much energy as burning 2,700,000 kg of coal. One US space reactor (SNAP-10A) flown (1965). Former U.S.S.R. flew 33 space reactors. Heat produced from neutron-induced splitting of a nucleus (e.g. U-235). At steady-state, 1 of the 2 to 3 neutrons released in the reaction causes a subsequent fission in a "chain reaction" process. Heat converted to electricity, or used directly to heat a propellant. Fission is highly versatile with many applications.

  9. Space Nuclear Power Systems

    Houts, Michael G.

    2012-01-01

    Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.

  10. Nuclearity for Dual Operator Spaces

    Zhe Dong; Jicheng Tao

    2010-02-01

    In this short paper, we study the nuclearity for the dual operator space $V^∗$ of an operator space . We show that $V^∗$ is nuclear if and only if $V^{∗∗∗}$ is injective, where $V^{∗∗∗}$ is the third dual of . This is in striking contrast to the situation for general operator spaces. This result is used to prove that $V^{∗∗}$ is nuclear if and only if is nuclear and $V^{∗∗}$ is exact.

  11. Nuclear propulsion for space exploration

    Miller, Thomas J.; Bennett, Gary L.

    1992-01-01

    The results of some recent studies of the application of both nuclear electric and nuclear thermal propulsion systems in space exploration are presented. Issues that require further study and which have a significant effect on the propulsion system design and selection are identified. Attention is given to robotic missions, lunar piloted and cargo missions, and Mars missions.

  12. Space nuclear reactor power plants

    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 space nuclear power plant components has been initiated by the Department of Energy. The missions that are foreseen, the current power plant concept, the technology program plan, and early key results are described

  13. In-space nuclear propulsion

    Bruno, C.; Dujarric, C.

    2013-02-01

    The past and the recent status of nuclear propulsion (NP) for application to space mission is presented. The case for using NP in manned space missions is made based on fundamental physics and on the necessity to ensure safe radiation doses to future astronauts. In fact, the presence of solar and galactic-cosmic radiation poses substantial risks to crews traveling for months in a row to destinations such as asteroids and Mars. Since passive or active shields would be massive to protect against the more energetic part of the radiation energy spectrum, the only alternative is to reduce dose by traveling faster. Hence the importance of propulsion systems with much higher specific impulse than that of current chemical systems, and thus the use of nuclear propulsion. Nuclear-thermal and nuclear-electric propulsions are then discussed in view of their potential application to missions now in the preliminary planning stage by space agencies and industries and being considered by the ISECG international panel. In this context, recent ideas for future use of the ISS that may require NP are also presented.

  14. Nuclear space power safety and facility guidelines study

    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 Missionsclose 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

  15. Space nuclear thermal propulsion program

    Haslett, R.A.

    1994-12-31

    This report describes te development and funding problems of the space nuclear thermal propulsion program (SNTP). The SNTP program was transferred to the air force, and almost immediately , they indicated that they would have to terminate the program because of a decreasing defense budget and other air force priorities. Congress continued to strongly support the program and $55 million was appropriated for fiscal year 1993, but the air force would not release any of the money to the program. By the summer of 1993, barely 18 months after the program was transferred to the air force, the SNTP team had essentially stopped all work and reduced to a skeleton staff to perform an orderly termination. Despite the significant accomplishments of the program and the endorsements it received from two DSBs, the 1994 Congressional Appropriations Committee had no alternative but to withhold further funding support since no cognizant agency (air force, NASA, or the DOE) was willing to take the lead and continue the technology for future space applications. Once again, the inability to forge cooperation between government agencies for a long-term goal doomed another nuclear technology program. The technology is currently being documented to the extent possible with existing funds because it is clear that a compact lightweight PBR space power and/or propulsion system will be required to enable unmanned and eventually manned exploration of the solar system.

  16. Nuclear Energy for Space Exploration

    Houts, Michael G.

    2010-01-01

    Nuclear power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system. Fusion and antimatter systems may also be viable in the future

  17. Nuclear energy in the space: panorama 1985

    A panoramic view of different areas where nuclear energy can be applied in space is given. These are: radioisotope thermoelectric generators, nuclear reactors for space stations, space crafts and air crafts. The principal difficulties are pointed out and the safety aspect is emphasized. (author)

  18. Space nuclear power and man's extraterrestrial civilization

    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

  19. Overview of space nuclear technologies and the American Nuclear Society

    The American Nuclear Society (ANS) has seen an aspect of the universe where nuclear technology is the best energy source available for power, transportation, etc. The National Aeronautics and Space Administration (NASA) has been exploiting this aspect of the universe by sending machines and humans into it and exploring, colonizing, industrializing, developing, inhabiting, etc. Space is the final frontier, and nuclear technology is the best suited for today's or the next century's space exploration and development. Many aspects of nuclear technology and its uses in space will be needed. ANS encompasses these and many more aspects of nuclear technology, and all have some role to play in the exploration and development of space. It should be ANS's intent to be an advisory body to NASA on the nuclear aspects of space exploration

  20. Autonomous Control of Space Nuclear Reactors Project

    National Aeronautics and Space Administration — Nuclear reactors to support future robotic and manned missions impose new and innovative technological requirements for their control and protection...

  1. A philosophy for space nuclear systems safety

    The unique requirements and contraints of space nuclear systems require careful consideration in the development of a safety policy. The Nuclear Safety Policy Working Group (NSPWG) for the Space Exploration Initiative has proposed a hierarchical approach with safety policy at the top of the hierarchy. This policy allows safety requirements to be tailored to specific applications while still providing reassurance to regulators and the general public that the necessary measures have been taken to assure safe application of space nuclear systems. The safety policy used by the NSPWG is recommended for all space nuclear programs and missions

  2. Coordinating Space Nuclear Research Advancement and Education

    The advancement of space exploration using nuclear science and technology has been a goal sought by many individuals over the years. The quest to enable space nuclear applications has experienced many challenges such as funding restrictions; lack of political, corporate, or public support; and limitations in educational opportunities. The Center for Space Nuclear Research (CSNR) was established at the Idaho National Laboratory (INL) with the mission to address the numerous challenges and opportunities relevant to the promotion of space nuclear research and education.1 The CSNR is operated by the Universities Space Research Association and its activities are overseen by a Science Council comprised of various representatives from academic and professional entities with space nuclear experience. Program participants in the CSNR include academic researchers and students, government representatives, and representatives from industrial and corporate entities. Space nuclear educational opportunities have traditionally been limited to various sponsored research projects through government agencies or industrial partners, and dedicated research centers. Centralized research opportunities are vital to the growth and development of space nuclear advancement. Coordinated and focused research plays a key role in developing the future leaders in the space nuclear field. The CSNR strives to synchronize research efforts and provide means to train and educate students with skills to help them excel as leaders.

  3. Nuclear Propulsion for Space (Rev.)

    Corliss, William R; Schwenk, Francis C

    1971-01-01

    The operation of nuclear rockets and a description of the development of nuclear rockets in the U.S. is given. Early developments and Project Rover, Project Pluto, and the NERVA (Nuclear Engine for Rocket Vehicle Application) Program are detailed. The Nuclear Rocket Development Station facilities in Nevada are described. The possibilities and advantages of using nuclear rockets for missions beginning from an earth orbit and moving outward toward higher earth orbits, the moon, and the planets are discussed.

  4. Overview of DOE space nuclear propulsion programs

    Newhouse, Alan R.

    1993-01-01

    An overview of Department of Energy space nuclear propulsion programs is presented in outline and graphic form. DOE's role in the development and safety assurance of space nuclear propulsion is addressed. Testing issues and facilities are discussed along with development needs and recent research activities.

  5. Space nuclear power: a strategy for tomorrow

    Buden, D.; Angelo, J. Jr.

    1981-01-01

    Energy: reliable, portable, abundant and low cost will be a most critical factor, perhaps the sine qua non, for the unfolding of man's permanent presence in space. Space-based nuclear power, in turn, is a key technology for developing such space platforms and the transportation systems necessary to service them. A strategy for meeting space power requirements is the development of a 100-kW(e) nuclear reactor system for high earth orbit missions, transportation from Shuttle orbits to geosynchronous orbit, and for outer planet exploration. The component technology for this nuclear power plant is now underway at the Los Alamos National Laboratory. As permanent settlements are established on the Moon and in space, multimegawatt power plants will be needed. This would involve different technology similar to terrestrial nuclear power plants.

  6. Fission ships[Nuclear space propulsion

    Kleiner, Kurt

    2000-12-02

    This article focuses on the paper project on the development of nuclear propulsion for space craft and considers the advantages and disadvantages of nuclear-powered rockets over conventional designs. Details are given of the miniature reactor engine, MITEE, its fuel elements fabricated from rolled metal sheets impregnated with uranium oxide fuel particles, its operation which is similar to that of a jet engine, and its anticipated use to travel through the atmosphere of Jupiter and to cut the travel time to planets. Public concern regarding nuclear energy is given as one of the reasons why NASA is unlikely to launch a nuclear-powered space craft in the near future.

  7. Autonomous Control of Space Nuclear Reactors Project

    National Aeronautics and Space Administration — Nuclear reactors to support future lunar and Mars robotic and manned missions impose new and innovative technological requirements for their control and protection...

  8. Transactions of the fourth symposium on space nuclear power systems

    El-Genk, M.S.; Hoover, M.D. (eds.)

    1987-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these papers include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, refractory alloys and high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  9. Transactions of the fifth symposium on space nuclear power systems

    El-Genk, M.S.; Hoover, M.D. (eds.)

    1988-01-01

    This paper contains the presented papers at the fourth symposium on space nuclear power systems. Topics of these paper include: space nuclear missions and applications, reactors and shielding, nuclear electric and nuclear propulsion, high-temperature materials, instrumentation and control, energy conversion and storage, space nuclear fuels, thermal management, nuclear safety, simulation and modeling, and multimegawatt system concepts. (LSP)

  10. Nuclear power engineering in space. Nuclear rocket engines

    Full text: This film tells about the scientific-technical conference on the problems of the nuclear rocket engine creation for space application. The mankind is at the threshold of flights to the nearest planets of the Solar system. Nuclear power transforms the fantasy into the reality. Nuclear power works not only at the nuclear plants of electric and heat supply but also in the powerful compact engines capable to transport space crafts with a man on board to the other planets of the Solar System. The International scientific-technical conference 'Nuclear Power Engineering in Space. Nuclear Rocket Engines', held in September 22-26, 1992 in Semipalatinsk (Kazakhstan) was dedicated to this topic discussed up to now only at the pages of fiction novels and confidential scientific papers. The leading USA firms occupied with problems of space and nuclear power engineering, scientific-research institutes of Russian Federation and Kazakhstan are among the Conference participants. The modern state-of-ths-art, problems, mathematical modeling of processes in NRE, technology of the high-temperature fuel creation, experimental abilities and achievements of the NRE ground running tests, ecological problems of the NRE tests and application were discussed at the Conference. The film includes video information about the first Soviet prototype nuclear propulsion facility (with maximum temperature about 3000 deg. C), that never was demonstrated before. (author)

  11. Nuclear energy propulsion in space

    Nuclear energy can be used under two different ways in spatial applications, first the most common is the production of electricity that is used to supply an electrical propulsion system. The second way is the thermal propulsion where the nuclear reactor is considered as a heat exchanger whose purpose is to heat a gas that will expand in a nozzle. The thermal propulsion implies that the nuclear fuel and some reactor components will have to sustain very high temperatures ( > 2000 K) and important temperature gradients over short time intervals. Because of size and mass constraints propulsion reactors require highly enriched uranium fuels, in such cases power densities reach 1 to 10 MW / liter of core, which is by 1 to 2 orders of magnitude bigger than in a PWR-type power reactor, this represents a true technological challenge. In this article 2 projects: ERATO concerning spatial power generation and MAPS concerning thermal propulsion are presented. (A.C.)

  12. Nuclear power: opening new vistas in space

    The nation faces a wide range of future civilian and military mission opportunities in space. However, many of the power requirements for these applications are beyond the capabilities of currently available energy sources. Nuclear energy can provide a prime source of this enabling power and the Department of Energy is fully committed to meeting the engineering and management challenges in developing nuclear power for space applications. The elements of the department's current Space Nuclear Power Program: Radioisotope Thermoelectric Generators (RTG's), Dynamic Isotope Power System (DIPS), Multi-Hundred Kilowatt Space Reactor Power System (SP-100), and Multimegawatt (MMW) Reactor Concepts are summarized. Several aspects of these efforts are discussed including Safety, Mission Focus, and Technology Development

  13. The nuclear energy use in Space

    Two ways of the nuclear energy use are possible in spatial applications. The first one is the electric power production to supply satellites, space vehicles or electric propulsion. The second one, less obvious, is the thermal-nuclear propulsion where the nuclear reactor is a thermal exchanger for a gas. These two applications are presented in this paper, with two examples of projects realized in collaboration of the CNES and the CEA: ERATO as an electrical generator and MAPS as the nucleo-thermal propulsion. (A.L.B.)

  14. Nuclear Electric Propulsion for Deep Space Exploration

    Schmidt, G.

    Nuclear electric propulsion (NEP) holds considerable promise for deep space exploration in the future. Research and development of this technology is a key element of NASA's Nuclear Systems Initiative (NSI), which is a top priority in the President's FY03 NASA budget. The goal is to develop the subsystem technologies that will enable application of NEP for missions to the outer planets and beyond by the beginning of next decade. The high-performance offered by nuclear-powered electric thrusters will benefit future missions by (1) reducing or eliminating the launch window constraints associated with complex planetary swingbys, (2) providing the capability to perform large spacecraft velocity changes in deep space, (3) increasing the fraction of vehicle mass allocated to payload and other spacecraft systems, and, (3) in some cases, reducing trip times over other propulsion alternatives. Furthermore, the nuclear energy source will provide a power-rich environment that can support more sophisticated science experiments and higher- speed broadband data transmission than current deep space missions. This paper addresses NASA's plans for NEP, and discusses the subsystem technologies (i.e., nuclear reactors, power conversion and electric thrusters) and system concepts being considered for the first generation of NEP vehicles.

  15. Telerobotic technology for nuclear and space applications

    Telerobotic development efforts at Oak Ridge National Laboratory are extensive and relatively diverse. Current efforts include development of a prototype space telerobot system for the NASA Langley Research Center and development and large-scale demonstration of nuclear fuel cycle teleoperators in the Consolidated Fuel Reprocessing Program. This paper presents an overview of the efforts in these major programs. 10 refs., 8 figs

  16. Nuclear Thermal Propulsion for Advanced Space Exploration

    Houts, M. G.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2012-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP).

  17. Space exploration with nuclear propulsion systems

    Venetoklis, P.

    1994-12-31

    One of the greatest obstacles to the human exploration of space has been the physical limit in the efficiency of chemical propulsion systems. Chemical propulsion has been a mature technology for decades, and efficiency improvements over this time span have amounted to only a few percent. The limits of chemical propulsion have forced the space exploration community to develop other strategies for overcoming the strictures imposed by gravity in their exploration pursuits. These strategies have their own limits and invariably result in increased costs and mission time. Nuclear propulsion does not face the same physical limitations as chemical propulsion. Nuclear thermal propulsion (NTP) systems generate twice the efficiency of the best modern chemical systems, and nuclear electric propulsion (NEP) systems promise efficiencies 10 to 20 times that of chemical propulsion. These dramatic improvements provide mission planners with such an enormous leap in capability that the full range of possibilities has yet to be identified. This paper identifies the range of missions identified to date that benefit from nuclear propulsion, attempts to quantify the benefits, and discusses issues associated with the incorporation of nuclear propulsion into spacecraft.

  18. Multi-mode nuclear space power systems

    This paper is concerned with early versions of multi-mode nuclear space power systems (M-M NSPS) and their important mission applications for the early years of the next century. These systems are characterized as being capable of selectively operating over wide ranges of electric power levels and duty cycles and also produce direct propulsive thrust. Their special configurations will be composed of both current and neoteric elements and special configurations requiring substantial analysis, research, development and test

  19. Impact loading of a space nuclear powerplant

    Evgeny I. Kraus

    2013-04-01

    Full Text Available Preferred formulation of the problem in two space dimensions are described for solving the three fundamental equations of mechanics (conservation of mass, conservation of momentum, and conservation of energy. Models of the behavior of materials provide the closure to the three fundamentals equations for applications to problems in compressible fluid flow and solid mechanics. Models of fracture and damage are described. A caloric model of the equation of state is proposed to describe thermodynamic properties of solid materials with the phase transitions. Two-dimensional problems of a high-velocity impact of a space nuclear propulsion system reactor are solved. High-velocity impact problems of destruction of reactor are solved for the two cases: 1 at its crash landing on the Earth surface (the impact velocity being up to 400 m/s; 2 at its impact (with velocity up to 16 km/s with the space debris fragments.

  20. Nuclear space propulsion initiative in Brazil

    Guimaraes, Lamartine Nogueira Frutuoso; Nascimento, Jamil Alves do [Institute for Advanced Studies, Sao Jose dos Campos, SP (Brazil). Nuclear Energy Div.]. E-mail: guimarae@ieav.cta.br; Camillo, Giannino Ponchio [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)]. E-mail: gianninocamillo@gmail.com

    2007-07-01

    This paper presents an account of the initial nuclear space propulsion activities at the Institute for Advanced Studies. At this point two laboratories have been assembled: one for heat pipe construction and testing and another one for thermal cycle analysis. It has also started the design of a thermal loop to study heat extraction and electricity generation in a NEP, the development of a dynamic mathematical model to represent this thermal loop, the selection of gas mixtures as working fluids to the thermal cycle, the production of two heat pipes for properties measurements and to establish design criteria to assemble heat pipes to be used as a heat rejection system. For the reactor core area a review of the core concepts proposed in other countries for space applications was initiated. This review will enable the choice of a core concept suitable to Brazilian needs in space. (author)

  1. Tethered nuclear power for the space station

    A nuclear space power system the SP-100 is being developed for future missions where large amounts of electrical power will be required. Although it is primarily intended for unmanned spacecraft, it can be adapted to a manned space platform by tethering it above the station through an electrical transmission line which isolates the reactor far away from the inhabited platform and conveys its power back to where it is needed. The transmission line, used in conjunction with an instrument rate shield, attenuates reactor radiation in the vicinity of the space station to less than one-one hundredth of the natural background which is already there. This combination of shielding and distance attenuation is less than one-tenth the mass of boom-mounted or onboard man-rated shields that are required when the reactor is mounted nearby. This paper describes how connection is made to the platform (configuration, operational requirements) and introduces a new element the coaxial transmission tube which enables efficient transmission of electrical power through long tethers in space. Design methodology for transmission tubes and tube arrays is discussed. An example conceptual design is presented that shows SP-100 at three power levels 100 kWe, 300 kWe, and 1000 kWe connected to space station via a 2 km HVDC transmission line/tether. Power system performance, mass, and radiation hazard are estimated with impacts on space station architecture and operation. 23 references

  2. Performance Criteria of Nuclear Space Propulsion Systems

    Shepherd, L. R.

    Future exploration of the solar system on a major scale will require propulsion systems capable of performance far greater than is achievable with the present generation of rocket engines using chemical propellants. Viable missions going deeper into interstellar space will be even more demanding. Propulsion systems based on nuclear energy sources, fission or (eventually) fusion offer the best prospect for meeting the requirements. The most obvious gain coming from the application of nuclear reactions is the possibility, at least in principle, of obtaining specific impulses a thousandfold greater than can be achieved in chemically energised rockets. However, practical considerations preclude the possibility of exploiting the full potential of nuclear energy sources in any engines conceivable in terms of presently known technology. Achievable propulsive power is a particularly limiting factor, since this determines the acceleration that may be obtained. Conventional chemical rocket engines have specific propulsive powers (power per unit engine mass) in the order of gigawatts per tonne. One cannot envisage the possibility of approaching such a level of performance by orders of magnitude in presently conceivable nuclear propulsive systems. The time taken, under power, to reach a given terminal velocity is proportional to the square of the engine's exhaust velocity and the inverse of its specific power. An assessment of various nuclear propulsion concepts suggests that, even with the most optimistic assumptions, it could take many hundreds of years to attain the velocities necessary to reach the nearest stars. Exploration within a range of the order of a thousand AU, however, would appear to offer viable prospects, even with the low levels of specific power of presently conceivable nuclear engines.

  3. Proceedings of the eighth symposium on space nuclear power systems

    The eighth symposium on Space Nuclear Power Systems was held in Albuquerque, New Mexico. Separate abstracts have been prepared for the papers presented in Part Three of the conference proceedings in the following areas of interest: space power electronics; heat pipe technology; space nuclear fuels for propulsion reactors; power systems concepts; use of artificial intelligence in space; key issues in space nuclear power; flight qualifications and testing (including SP-100 nuclear assembly test program); microgravity two phase flow; simulation and modeling; manufacturing and processing; and space environmental effects. (MB)

  4. Non-Nuclear Testing of Space Nuclear Systems at NASA MSFC

    Houts, Michael G.; Pearson, Boise J.; Aschenbrenner, Kenneth C.; Bradley, David E.; Dickens, Ricky; Emrich, William J.; Garber, Anne; Godfroy, Thomas J.; Harper, Roger T.; Martin, Jim J.; Polzin, Kurt; Schoenfeld, Michael P.; Webster, Kenneth L.

    2010-01-01

    Highly realistic non-nuclear testing can be used to investigate and resolve potential issues with space nuclear power and propulsion systems. Non-nuclear testing is particularly useful for systems designed with fuels and materials operating within their demonstrated nuclear performance envelope. Non-nuclear testing allows thermal hydraulic, heat transfer, structural, integration, safety, operational, performance, and other potential issues to be investigated and resolved with a greater degree of flexibility and at reduced cost and schedule compared to nuclear testing. The primary limit of non-nuclear testing is that nuclear characteristics and potential nuclear issues cannot be directly investigated. However, non-nuclear testing can be used to augment the potential benefit from any nuclear testing that may be required for space nuclear system design and development. This paper describes previous and ongoing non-nuclear testing related to space nuclear systems at NASA's Marshall Space Flight Center (MSFC).

  5. Proceedings of the eighth symposium on space nuclear power systems

    The eighth symposium on Space Nuclear Power Systems was held in Albuquerque, New Mexico. Separate abstracts have been prepared for the papers presented in Part One of the conference proceedings in the following areas of interest: space applications/exploration; space nuclear safety (including Ulysses safety analysis and evaluation); reactor materials; reactors and shielding; space missions and power needs; nuclear electric propulsion: systems concepts; and static energy conversion systems. (MB)

  6. Space nuclear power, propulsion, and related technologies.

    Berman, Marshall

    1992-01-01

    Sandia National Laboratories (Sandia) is one of the nation's largest research and development (R&D) facilities, with headquarters at Albuquerque, New Mexico; a laboratory at Livermore, California; and a test range near Tonopah, Nevada. Smaller testing facilities are also operated at other locations. Established in 1945, Sandia was operated by the University of California until 1949, when, at the request of President Truman, Sandia Corporation was formed as a subsidiary of Bell Lab's Western Electric Company to operate Sandia as a service to the U.S. Government without profit or fee. Sandia is currently operated for the U.S. Department of Energy (DOE) by AT&T Technologies, Inc., a wholly-owned subsidiary of AT&T. Sandia's responsibility is national security programs in defense and energy with primary emphasis on nuclear weapon research and development (R&D). However, Sandia also supports a wide variety of projects ranging from basic materials research to the design of specialized parachutes. Assets, owned by DOE and valued at more than $1.2 billion, include about 600 major buildings containing about 372,000 square meters (m2) (4 million square feet [ft2]) of floor space, located on land totalling approximately 1460 square kilometers (km2) (562 square miles [mi]). Sandia employs about 8500 people, the majority in Albuquerque, with about 1000 in Livermore. Approximately 60% of Sandia's employees are in technical and scientific positions, and the remainder are in crafts, skilled labor, and administrative positions. As a multiprogram national laboratory, Sandia has much to offer both industrial and government customers in pursuing space nuclear technologies. The purpose of this brochure is to provide the reader with a brief summary of Sandia's technical capabilities, test facilities, and example programs that relate to military and civilian objectives in space. Sandia is interested in forming partnerships with industry and government

  7. Propulsion of space ships by nuclear explosion

    Linhart, J. G.; Kravárik, J.

    2005-01-01

    Recent progress in the research on deuterium-tritium (D-T) inertially confined microexplosions encourages one to reconsider the nuclear propulsion of spaceships based on the concept originally proposed in the Orion project. We discuss first the acceleration of medium-sized spaceships by D-T explosions whose output is in the range of 0.1 10 t of TNT. The launching of such a ship into an Earth orbit or beyond by a large nuclear explosion in an underground cavity is sketched out in the second section of the paper, and finally we consider a hypothetical Mars mission based on these concepts. In the conclusion it is argued that propulsion based on the Orion concept only is not the best method for interplanetary travel owing to the very large number of nuclear explosion required. A combination of a super gun and subsequent rocket propulsion using advanced chemical fuels appears to be the best solution for space flights of the near future.

  8. The role of nuclear reactors in space exploration and development

    The United States has launched more than 20 radioisotopic thermoelectric generators (RTGs) into space over the past 30 yr but has launched only one nuclear reactor, and that was in 1965. Russia has launched more than 30 reactors. The RTGs use the heat of alpha decay of 238Pu for power and typically generate 235U; typical designs are for 100 to 1000 kW of electricity. The only US space reactor launch (SNAP-10A) was a demonstration mission. One reason for the lack of space reactor use by the United States was the lack of space missions that required high power. But, another was the assumed negative publicity that would accompany a reactor launch. The net result is that all space reactor programs after 1970 were terminated before an operating space reactor could be developed, and they are now many years from recovering the ability to build them. Two major near-term needs for space reactors are the human exploration of Mars and advanced missions to and beyond the orbit of Jupiter. To help obtain public acceptance of space reactors, one must correct some of the misconceptions concerning space reactors and convey the following facts to the public and to decision makers: Space reactors are 1000 times smaller in power and size than a commercial power reactor. A space reactor at launch is only as radioactive as a pile of dirt 60 m (200 ft) across. A space reactor contains no plutonium at launch. It does not become significantly radioactive until it is turned on, and it will be engineered so that no launch accident can turn it on, even if that means fueling it after launch. The reactor will not be turned on until it is in a high stable orbit or even on an earth-escape trajectory for some missions. The benefits of space reactors are that they give humanity a stairway to the planets and perhaps the stars. They open a new frontier for their children and their grandchildren. They pave the way for all life on earth to move out into the solar system. At one time, humans built and

  9. Spaces of Flows 1.0: A working experience using Sixth Sense Transport technology

    Dickinson, Janet; Speed, Chris

    2013-01-01

    The networks that constitute businesses, organisations and social groups often retain consistent patterns of movement and flow across time and space. Tourists visit the same locations in a city, shops use the consistent suppliers who in turn use the same routes to supply goods to the shops, and social networks walk the same streets to the same bars on a regular basis. Although not predictable, these patterns may allow opportunities for exchange and potentially energy saving if networks are sh...

  10. Nuclear-safety criteria and specifications for space nuclear reactors

    The policy of the United States for all US nuclear power sources in space is to ensure that the probability of release of radioactive material and the amounts released are such that an undue risk is not presented, considering the benefits of the mission. The objective of this document is to provide safety criteria which a mission/reactor designer can use to help ensure that the design is acceptable from a radiological safety standpoint. These criteria encompass mission design, reactor design, and radiological impact limitation requirements for safety, and the documentation required. They do not address terrestrial operations, occupational safety or system reliability except where the systems are important for radiological safety. Specific safety specifications based on these criteria shall also be generated and made part of contractual requirements

  11. Space parity violation in nuclear fission

    Space parity violation in low energy fission was observed by the Soviet physicists in 1977 in the course of the angular distribution investigations of the light and heavy fragments in the polarized thermal neutron fission of 233,235U and 239Pu. Unexpected large values of the P-odd asymmetry coefficients (αnf ∼ 10-4) were obtained in the angular distribution W(0) = 1 + bar αnf (bar σn · pf). So large values of αnf looked very strange because of the existence of numerous different exit channels in fission process (∼108 - 1010) and a small relative value of nonconserving space parity potential of the weak NN-interaction (∼ 10-7). In addition to the P-violating asymmetry bar αnf P-conserving right-left asymmetry of the fission fragment angular distribution W (θ) = 1 + α RLnf pf · αn x pf was observed in 1979. The main goal of the new experimental investigations of P-odd and P-even effects in fission was a search of the possible relationships between the asymmetry coefficients and the characteristics of the entrance and exit channels in slow neutron fission. In this paper the brief review of the experimental results obtained by different groups is given. The main part of these results have been obtained at the WWR-M reactor of Leningrad Nuclear Physics Institute (LNPI)

  12. Titanium Loop Heat Pipes for Space Nuclear Radiators Project

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will develop titanium Loop Heat Pipes (LHPs) that can be used in low-mass space nuclear radiators, such as...

  13. Nuclear modules for space electric propulsion

    Difilippo, F. C.

    1998-01-01

    The analysis of interplanetary cargo and piloted missions requires the calculations of the performances and masses of subsystems to be integrated in a final design. In a preliminary and scoping stage the designer needs to evaluate options in an iterative way by using simulations that run fast on a computer. As a consequence of a collaborative agreement between the National Aeronautic and Space Administration (NASA) and the Oak Ridge National Laboratory (ORNL), ORNL has been involved in the development of models and calculational procedures for the analysis (neutronic and thermal hydraulic) of power sources for nuclear electric propulsion. The nuclear modules will be integrated into the whole simulation of the nuclear electric propulsion system. The vehicles use either a Brayton direct-conversion cycle, using the heated helium from a NERVA-type reactor, or a potassium Rankine cycle, with the working fluid heated on the secondary side of a heat exchanger and lithium on the primary side coming from a fast reactor. Given a set of input conditions, the codes calculate composition, dimensions, volumes, and masses of the core, reflector, control system, pressure vessel, neutron and gamma shields, as well as the thermal hydraulic conditions of the coolant, clad and fuel. Input conditions are power, core life, pressure and temperature of the coolant at the inlet of the core, either the temperature of the coolant at the outlet of the core or the coolant mass flow and the fluences and integrated doses at the cargo area. Using state-of-the-art neutron cross sections and transport codes, a database was created for the neutronic performance of both reactor designs. The free parameters of the models are the moderator/fuel mass ratio for the NERVA reactor and the enrichment and the pitch of the lattice for the fast reactor. Reactivity and energy balance equations are simultaneously solved to find the reactor design. Thermalhydraulic conditions are calculated by solving the one

  14. Nuclear modules for space electric propulsion

    Difilippo, F.C. [Oak Ridge National Laboratory, P.O. Box 2008, Bldg. 6025, Oak Ridge, Tennessee 37831-6363 (United States)

    1998-01-01

    The analysis of interplanetary cargo and piloted missions requires the calculations of the performances and masses of subsystems to be integrated in a final design. In a preliminary and scoping stage the designer needs to evaluate options in an iterative way by using simulations that run fast on a computer. As a consequence of a collaborative agreement between the National Aeronautic and Space Administration (NASA) and the Oak Ridge National Laboratory (ORNL), ORNL has been involved in the development of models and calculational procedures for the analysis (neutronic and thermal hydraulic) of power sources for nuclear electric propulsion. The nuclear modules will be integrated into the whole simulation of the nuclear electric propulsion system. The vehicles use either a Brayton direct-conversion cycle, using the heated helium from a NERVA-type reactor, or a potassium Rankine cycle, with the working fluid heated on the secondary side of a heat exchanger and lithium on the primary side coming from a fast reactor. Given a set of input conditions, the codes calculate composition, dimensions, volumes, and masses of the core, reflector, control system, pressure vessel, neutron and gamma shields, as well as the thermal hydraulic conditions of the coolant, clad and fuel. Input conditions are power, core life, pressure and temperature of the coolant at the inlet of the core, either the temperature of the coolant at the outlet of the core or the coolant mass flow and the fluences and integrated doses at the cargo area. Using state-of-the-art neutron cross sections and transport codes, a database was created for the neutronic performance of both reactor designs. The free parameters of the models are the moderator/fuel mass ratio for the NERVA reactor and the enrichment and the pitch of the lattice for the fast reactor. Reactivity and energy balance equations are simultaneously solved to find the reactor design. Thermalhydraulic conditions are calculated by solving the one

  15. Coordinate-space picture of nuclear structure functions

    We discuss quark mobility distributions Q (y+) defined as Fourier transformations of momentum-space structure functions F2(xBj). We find that nuclear effects in coordinate space are negligible for light-cone distances y+ (Ioffe times) up to 5 fm. At large y+, nuclear shadowing sets in. (author)

  16. Startup control of the TOPAZ-II space nuclear reactor

    Astrin, Cal D.

    1996-01-01

    Approved for public release; distribution isunlimited. The Russian designed and manufactured TOPAZ-II Thermionic Nuclear Space Reactor has been supplied to the Ballistic Missile Defense Organization for study as part of the TOPAZ International Program. A Preliminary Nuclear Safety Assessment investigated the readiness to use the TOPAZ-II in support of a Nuclear Electric Propulsion Space Test Mission (NEPSTP). Among the anticipated system modifications required for launching the TOPAZ-II sy...

  17. Legal Implications of Nuclear Propulsion for Space Objects

    Pop, V.

    2002-01-01

    This paper is intended to examine nuclear propulsion concepts such as "Project Orion", "Project Daedalus", NERVA, VASIMIR, from the legal point of view. The UN Principles Relevant to the Use of Nuclear Power Sources in Outer Space apply to nuclear power sources in outer space devoted to the generation of electric power on board space objects for non-propulsive purposes, and do not regulate the use of nuclear energy as a means of propulsion. However, nuclear propulsion by means of detonating atomic bombs (ORION) is, in principle, banned under the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water. The legality of use of nuclear propulsion will be analysed from different approaches - historical (i.e. the lawfulness of these projects at the time of their proposal, at the present time, and in the future - in the light of the mutability and evolution of international law), spatial (i.e. the legal regime governing peaceful nuclear explosions in different spatial zones - Earth atmosphere, Earth orbit, Solar System, and interstellar space), and technical (i.e, the legal regime applicable to different nuclear propulsion techniques, and to the various negative effects - e.g. damage to other space systems as an effect of the electromagnetic pulse, etc). The paper will analyse the positive law, and will also come with suggestions "de lege ferenda".

  18. Space Nuclear Propulsion Systems and Applications

    Schwenk, F. C.

    1972-01-01

    The basic principles of the operation of a nuclear rocket engine are reviewed along with a summary of the early history. In addition, the technology status in the nuclear rocket program for development of the flight-rated NERVA engine is described, and applications for this 75,000-pound thrust engine and the results of nuclear stage studies are presented. Advanced research and supporting technology activities in the nuclear rocket program are also summarized.

  19. Space nuclear reactors: energy gateway into the next millennium

    Power - reliable, abundant and economic - is the key to man's conquest of the Solar System. Space activities of the next few decades will be highlighted by the creation of the extraterrestrial phase of human civilization. Nuclear power is needed both to propel massive quantities of materials through cislunar and eventually translunar space, and to power the sophisticated satellites, space platforms, and space stations of tomorrow. To meet these anticipated future space power needs, the Los Alamos National Laboratory is developing components for a compact, 100-kW(e) heat pipe nuclear reactor. The objectives of this program are to develop components for a space nuclear power plant capable of unattended operation for 7 to 10 years; having a reliability of greater than 0.95; and weighing less than 1910 kg. In addition, this heat pipe reactor is also compatible for launch by the US Space Transportation System

  20. Ongoing Space Nuclear Systems Development in the United States

    Reliable, long-life power systems are required for ambitious space exploration missions. Nuclear power and propulsion options can enable a bold, new set of missions and introduce propulsion capabilities to achieve access to science destinations that are not possible with more conventional systems. Space nuclear power options can be divided into three main categories: radioisotope power for heating or low power applications; fission power systems for non-terrestrial surface application or for spacecraft power; and fission power systems for electric propulsion or direct thermal propulsion. Each of these areas has been investigated in the United States since the 1950s, achieving various stages of development. While some nuclear systems have achieved flight deployment, others continue to be researched today. This paper will provide a brief overview of historical space nuclear programs in the U.S. and will provide a summary of the ongoing space nuclear systems research, development, and deployment in the United States.

  1. Ongoing Space Nuclear Systems Development in the United States

    S. Bragg-Sitton; J. Werner; S. Johnson; Michael G. Houts; Donald T. Palac; Lee S. Mason; David I. Poston; A. Lou Qualls

    2011-10-01

    Reliable, long-life power systems are required for ambitious space exploration missions. Nuclear power and propulsion options can enable a bold, new set of missions and introduce propulsion capabilities to achieve access to science destinations that are not possible with more conventional systems. Space nuclear power options can be divided into three main categories: radioisotope power for heating or low power applications; fission power systems for non-terrestrial surface application or for spacecraft power; and fission power systems for electric propulsion or direct thermal propulsion. Each of these areas has been investigated in the United States since the 1950s, achieving various stages of development. While some nuclear systems have achieved flight deployment, others continue to be researched today. This paper will provide a brief overview of historical space nuclear programs in the U.S. and will provide a summary of the ongoing space nuclear systems research, development, and deployment in the United States.

  2. Space nuclear power supply design in the shuttle ERA

    Developing technology and the transition period of the late 1970's from expendable launchers to reusable space shuttles and from single satellite designs to standardized and modularized configurations represents a strong motivation and unique opportunity to actively investigate new applications of nuclear power for satellites. The work reported here consists of a many faceted effort to establish nuclear power supply design guidelines for space missions through the 1980s. Configuration, integration, and launch constraints are reviewed. Of particular interest is the space shuttle system and new technologies related to nuclear power. These will require significant new innovations to optimize future missions

  3. Recent measurements for hadrontherapy and space radiation: nuclear physics

    Miller, J.

    2001-01-01

    The particles and energies commonly used for hadron therapy overlap the low end of the charge and energy range of greatest interest for space radiation applications, Z=1-26 and approximately 100-1000 MeV/nucleon. It has been known for some time that the nuclear interactions of the incident ions must be taken into account both in treatment planning and in understanding and addressing the effects of galactic cosmic ray ions on humans in space. Until relatively recently, most of the studies of nuclear fragmentation and transport in matter were driven by the interests of the nuclear physics and later, the hadron therapy communities. However, the experimental and theoretical methods and the accelerator facilities developed for use in heavy ion nuclear physics are directly applicable to radiotherapy and space radiation studies. I will briefly review relevant data taken recently at various accelerators, and discuss the implications of the measurements for radiotherapy, radiobiology and space radiation research.

  4. Space Nuclear Space Program. Progress report, December 1983

    Bronisz, S.E. (comp.)

    1984-06-01

    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. Results from safety-verification tests including impact tests are presented.

  5. Recent Advances in Nuclear Powered Electric Propulsion for Space Exploration

    Cassady, R. Joseph; Frisbee, Robert H.; Gilland, James H.; Houts, Michael G.; LaPointe, Michael R.; Maresse-Reading, Colleen M.; Oleson, Steven R.; Polk, James E.; Russell, Derrek; Sengupta, Anita

    2007-01-01

    Nuclear and radioisotope powered electric thrusters are being developed as primary in-space propulsion systems for potential future robotic and piloted space missions. Possible applications for high power nuclear electric propulsion include orbit raising and maneuvering of large space platforms, lunar and Mars cargo transport, asteroid rendezvous and sample return, and robotic and piloted planetary missions, while lower power radioisotope electric propulsion could significantly enhance or enable some future robotic deep space science missions. This paper provides an overview of recent U.S. high power electric thruster research programs, describing the operating principles, challenges, and status of each technology. Mission analysis is presented that compares the benefits and performance of each thruster type for high priority NASA missions. The status of space nuclear power systems for high power electric propulsion is presented. The paper concludes with a discussion of power and thruster development strategies for future radioisotope electric propulsion systems,

  6. Recent advances in nuclear powered electric propulsion for space exploration

    Cassady, R. Joseph [Aerojet Corp., Redmond, CA (United States); Frisbee, Robert H. [Jet Propulsion Laboratory, Pasadena, CA (United States); Gilland, James H. [Ohio Aerospace Institute, Cleveland, OH (United States); Houts, Michael G. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); LaPointe, Michael R. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)], E-mail: michael.r.lapointe@nasa.gov; Maresse-Reading, Colleen M. [Jet Propulsion Laboratory, Pasadena, CA (United States); Oleson, Steven R. [NASA Glenn Research Center, Cleveland, OH (United States); Polk, James E. [Jet Propulsion Laboratory, Pasadena, CA (United States); Russell, Derrek [Northrop Grumman Space Technology, Redondo Beach, CA (United States); Sengupta, Anita [Jet Propulsion Laboratory, Pasadena, CA (United States)

    2008-03-15

    Nuclear and radioisotope powered electric thrusters are being developed as primary in space propulsion systems for potential future robotic and piloted space missions. Possible applications for high-power nuclear electric propulsion include orbit raising and maneuvering of large space platforms, lunar and Mars cargo transport, asteroid rendezvous and sample return, and robotic and piloted planetary missions, while lower power radioisotope electric propulsion could significantly enhance or enable some future robotic deep space science missions. This paper provides an overview of recent US high-power electric thruster research programs, describing the operating principles, challenges, and status of each technology. Mission analysis is presented that compares the benefits and performance of each thruster type for high priority NASA missions. The status of space nuclear power systems for high-power electric propulsion is presented. The paper concludes with a discussion of power and thruster development strategies for future radioisotope electric propulsion systems.

  7. Importance of Nuclear Physics to NASA's Space Missions

    Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

    2001-01-01

    We show that nuclear physics is extremely important for accurate risk assessments for space missions. Due to paucity of experimental input radiation interaction information it is imperative to develop reliable accurate models for the interaction of radiation with matter. State-of-the-art nuclear cross sections models have been developed at the NASA Langley Research center and are discussed.

  8. Planning for the Space Exploration Initiative - The nuclear propulsion option

    Bennett, Gary L.; Miller, Thomas J.

    1991-01-01

    The Space Exploration Initiative includes both lunar and Mars program elements as well as robotic science missions. Space transportation is a primary part of all planning for exploration. The high performance propulsion capabilities of nuclear propulsion offer the potential to reduce substantially the flight times to and from Mars and to reduce the mass launched into low earth orbit.

  9. Safety aspects of nuclear waste disposal in space

    Rice, E. E.; Edgecombe, D. S.; Compton, P. R.

    1981-01-01

    Safety issues involved in the disposal of nuclear wastes in space as a complement to mined geologic repositories are examined as part of an assessment of the feasibility of nuclear waste disposal in space. General safety guidelines for space disposal developed in the areas of radiation exposure and shielding, containment, accident environments, criticality, post-accident recovery, monitoring systems and isolation are presented for a nuclear waste disposal in space mission employing conventional space technology such as the Space Shuttle. The current reference concept under consideration by NASA and DOE is then examined in detail, with attention given to the waste source and mix, the waste form, waste processing and payload fabrication, shipping casks and ground transport vehicles, launch site operations and facilities, Shuttle-derived launch vehicle, orbit transfer vehicle, orbital operations and space destination, and the system safety aspects of the concept are discussed for each component. It is pointed out that future work remains in the development of an improved basis for the safety guidelines and the determination of the possible benefits and costs of the space disposal option for nuclear wastes.

  10. Evaluating Russian space nuclear reactor technology for United States applications

    Space nuclear power and nuclear electric propulsion are considered important technologies for planetary exploration, as well as selected earth orbit applications. The Nuclear Electric Propulsion Space Test Program (NEPSTP) was intended to provide an early flight demonstration of these technologies at relatively low cost through extensive use of existing Russian technology. The key element of Russian technology employed in the program was the Topaz II reactor. Refocusing of the activities of the Ballistic Missile Defense Organization (BMDO), combined with budgetary pressures, forced the cancellation of the NEPSTP at the end of the 1993 fiscal year. The NEPSTP was faced with many unique flight qualification issues. In general, the launch of a spacecraft employing a nuclear reactor power system complicates many spacecraft qualification activities. However, the NEPSTP activities were further complicated because the reactor power system was a Russian design. Therefore, this program considered not only the unique flight qualification issues associated with space nuclear power, but also with differences between Russian and United States flight qualification procedures. This paper presents an overview of the NEPSTP. The program goals, the proposed mission, the spacecraft, and the Topaz II space nuclear power system are described. The subject of flight qualification is examined and the inherent difficulties of qualifying a space reactor are described. The differences between United States and Russian flight qualification procedures are explored. A plan is then described that was developed to determine an appropriate flight qualification program for the Topaz II reactor to support a possible NEPSTP launch

  11. The benefits of using nuclear electric propulsion in space.

    Detsis, Emmanouil; Bauer, Waldemar; CLIQUET-MORENO, Elisa; Gaia, Enrico; Hodgson, Zara; Jansen, Frank; Koroteev, Anatoliy; Masson, Frederic; Semenkin, Alexander; Tinsley, Tim; Tosi, Maria Cristina; RUAULT, Jean-Marc; Worms, Jean-Claude

    2014-01-01

    Nuclear Electric Propulsion (NEP) can offer multiple advantages in regards to space exploration. Significant gains can be realised in flight time (by eliminating the need for gravity assists, even for deep space missions), on-board power availability (with a power level an order of magnitude higher of what is available today) and payload mass delivered to the selected target. To deliver a spacecraft in the 2030-2040 timeframe, necessary ground and space demonstration missions will be required...

  12. Opening up the future in space with nuclear power

    Man's extraterrestrial development is dependent on abundant power. For example, space-based manufacturing facilities are projected to have a power demand of 300 kWe by the end of this Century, and several megawatts in the early part of next millennium. The development of the lunar resource base will result in power needs ranging from an initial 100 kW(e) to many megawatts. Human visits to Mars could be achieved using a multimegawatt nuclear electric propulsion system or high thrust nuclear rockets. Detailed exploration of the solar system will also be greatly enhanced by the availability of large nuclear electric propulsion systems. All of these activities will require substantial increases in space power - hundreds of kilowatts to many megawatts. The challenge is clear: how to effectively use nuclear energy to support humanity's expansion into space

  13. Proposal of Space Reactor for Nuclear Electric Propulsion System

    Nagata, Hidetaka; Nishiyama, Takaaki; Nakashima, Hideki

    Currently, the solar battery, the chemical cell, and the RI battery are used for the energy source in space. However, it is difficult for them to satisfy requirements for deep space explorations. Therefore, other electric power sources which can stably produce high electric energy output, regardless of distance from the sun, are necessary to execute such missions. Then, we here propose small nuclear reactors as power sources for deep space exploration, and consider a conceptual design of a small nuclear reactor for Nuclear Electric Propulsion System. It is found from nuclear analyses that the Gas-Cooled reactor could not meet the design requirement imposed on the core mass. On the other hand, a light water reactor is found to be a promising alternative to the Gas-Cooled reactor.

  14. Effects of Nuclear Interactions on Accuracy of Space Radiation Transport

    Lin, Zi-Wei; Barghouty, A. F.

    2005-01-01

    Space radiation risk to astronauts and electronic equipments is one major obstacle in long term human space explorations. Space radiation transport codes have been developed to calculate radiation effects behind materials in human missions to the Moon, Mars or beyond. We study how nuclear fragmentation processes affect the accuracy of predictions from such radiation transport. In particular, we investigate the effects of fragmentation cross sections at different energies on fluxes, dose and dose-equivalent from galactic cosmic rays behind typical shielding materials. These results tell us at what energies nuclear cross sections are the most important for radiation risk evaluations, and how uncertainties in our knowledge about nuclear fragmentations relate to uncertainties in space transport predictions.

  15. Space Nuclear Thermal Propulsion Test Facilities Subpanel. Final report

    On 20 Jul. 1989, in commemoration of the 20th anniversary of the Apollo 11 lunar landing, President George Bush proclaimed his vision for manned space exploration. He stated, 'First for the coming decade, for the 1990's, Space Station Freedom, the next critical step in our space endeavors. And next, for the new century, back to the Moon. Back to the future. And this time, back to stay. And then, a journey into tomorrow, a journey to another planet, a manned mission to Mars.' On 2 Nov. 1989, the President approved a national space policy reaffirming the long range goal of the civil space program: to 'expand human presence and activity beyond Earth orbit into the solar system.' And on 11 May 1990, he specified the goal of landing Astronauts on Mars by 2019, the 50th anniversary of man's first steps on the Moon. To safely and ever permanently venture beyond near Earth environment as charged by the President, mankind must bring to bear extensive new technologies. These include heavy lift launch capability from Earth to low-Earth orbit, automated space rendezvous and docking of large masses, zero gravity countermeasures, and closed loop life support systems. One technology enhancing, and perhaps enabling, the piloted Mars missions is nuclear propulsion, with great benefits over chemical propulsion. Asserting the potential benefits of nuclear propulsion, NASA has sponsored workshops in Nuclear Electric Propulsion and Nuclear Thermal Propulsion and has initiated a tri-agency planning process to ensure that appropriate resources are engaged to meet this exciting technical challenge. At the core of this planning process, NASA, DOE, and DOD established six Nuclear Propulsion Technical Panels in 1991 to provide groundwork for a possible tri-agency Nuclear Propulsion Program and to address the President's vision by advocating an aggressive program in nuclear propulsion. To this end the Nuclear Electric Propulsion Technology Panel has focused it energies

  16. Space nuclear power: Key to outer solar system exploration

    In 1995, in response to threatened budget cuts, the American Institute of Aeronautics and Astronautics (AIAA) approved a position paper supporting the maintenance of the technology base for space nuclear power. The position paper contained four recomemndations: (1) DOE, NASA, and DoD should develop and support an integrated program that maintains the nuclear option and develops the needed high-payoff technologies; (2) Congress should provide strong, continuing financial and political support for the agencies' program; (3) Government and industry leaders should voice their advocacy for a strong space nuclear power program to support future system requirements; and (4) The US should continue to maintain its cooperation and technical interchanges with other countries to advance nuclear power source technology and to promote nuclear safety

  17. Nuclear electric ion propulsion for three deep space missions

    Chiravalle, Vincent P.

    2008-03-01

    Nuclear electric ion propulsion is considered for three sample deep space missions starting from a 500 km low Earth orbit encompassing the transfer of a 100 MT payload into a 1500 km orbit around Mars, the rendezvous of a 10 MT payload with the Jovian moon Europa and the rendezvous of a similar payload with Saturn's moon Titan. Near term ion engine and space nuclear reactor technology are assumed. It is shown that nuclear electric ion propulsion offers more than twice the payload for the Mars mission relative to the case when a nuclear thermal rocket is used for the trans-Mars injection maneuver at Earth, and about the same payload advantage relative to the case when solar electric propulsion is used for the Mars heliocentric transfer. For missions to the outer planets nuclear electric ion propulsion increases the payload mass fraction by a factor of two or more compared with high thrust systems that utilize gravity assist trajectories.

  18. Advanced materials for space nuclear power systems

    Research on monolithic refractory metal alloys and on metal matrix composites is being conducted at the NASA Lewis Research Center, Cleveland, Ohio, in support of advanced space power systems. The overall philosophy of the research is to develop and characterize new high-temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites (Gr/Cu) for heat rejection fins, and tungsten fiber reinforced niobium matrix composites (W/NB) for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications

  19. Advanced materials for space nuclear power systems

    Titran, Robert H.; Grobstein, Toni L.; Ellis, David L.

    1991-01-01

    The overall philosophy of the research was to develop and characterize new high temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites for heat rejection fins, and tungsten fiber reinforced niobium matrix composites for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  20. Infrared monitoring of nuclear power in space

    Using parameters for unclassified astronomical observatories based on Maui and on the Kuiper Airborne Observatory, we have determined the level of confidence of monitoring a ban on nuclear power in earth orbit. Existing military and astronomical observatories can detect and identify operating nuclear power sources on satellites, such as the Soviet RORSAT and American SP100, with a very high level of confidence to distances beyond geosynchronous orbit. A cold reactor can be detected with a medium level of confidence with visual observations by close-flying reconnaissance satellites with medium confidence, and in the future with very high confidence with the interrogation of neutrons. The smaller thermal sources, RTG and DIPS, could be detected with medium level of confidence under certain conditions. Large pulsed reactors can be detected with a medium confidence level with visual observations from close satellites, and with a very high level of confidence with neutron interrogation

  1. Infrared monitoring of nuclear power in space

    Hafemeister, David W.

    1988-12-01

    Using parameters for unclassified astronomical observatories based on Maui and on the Kuiper Airborne Observatory, we have determined the level of confidence of monitoring a ban on nuclear power in earth orbit. Existing military and astronomical observatories can detect and identify operating nuclear power sources on satellites, such as the Soviet RORSAT and American SP100, with a very high level of confidence to distances beyond geosynchronous orbit. A cold reactor can be detected with a medium level of confidence with visual observations by close-flying reconnaissance satellites with medium confidence, and in the future with very high confidence with the interrogation of neutrons. The smaller thermal sources, RTG and DIPS, could be detected with medium level of confidence under certain conditions. Large pulsed reactors can be detected with a medium confidence level with visual observations from close satellites, and with a very high level of confidence with neutron interrogation.

  2. Nuclear tumor suppressors in space and time.

    Barbie, David A; Conlan, Lindus A; Kennedy, Brian K

    2005-07-01

    Numerous studies have identified key binding partners and functional activities of nuclear tumor-suppressor proteins such as the retinoblastoma protein, p53 and BRCA1. Historically, less attention has been given to the subnuclear locations of these proteins. Here, we describe several recent studies that promote the view that regulated association with subcompartments of the nucleus is inherent to tumor-suppressor function. PMID:15936946

  3. ESA's approach to nuclear power sources for space applications

    Nuclear power sources for space (NPS) are, according to current physics knowledge, the only power source option for some classes of space missions. Europe has successfully used nuclear power sources for space exploration missions (e.g. Huygens lander on Titan, Ulysses spacecraft). While some small-scale study and development efforts have been undertaken at national level during the past 40 years, these did not go beyond study and early prototype designing level. In the light of further European integration and European ambitions in space, an independent working group involving European institutional stakeholders has discussed options and proposed coherent European positions concerning the safety, use and development of NPS technology in Europe. This paper presents safety aspects and options as identified by this European Working Group and ongoing related ESA (European Space Agency) activities in this field. (authors)

  4. Nuclear space power and propulsion requirements and issues

    The use of nuclear power in space is going through a low point. The kinds of missions that would use nuclear power are expensive and there are few new expensive missions. Both NASA and DoD are in a mode of cheaper, faster, better, which means using what is available as much as possible and only incorporating new technology to reduce mission cost. NASA is performing Mission to Planet Earth and detailed exploration missions of Mars. These NASA missions can be done with solar-battery power subsystems and there is no need for nuclear power. The NASA mission to Pluto does require nuclear radioisotope power. Ways to reduce the power subsystem cost and the power level are being investigated. NASA is studying ways to explore beyond Mars with solar-battery power because of the cost and uncertainty in the availability and launchability of nuclear space power systems. The DoD missions are all in earth orbit and can be done with solar-battery systems. The major DoD requirement at present is to reduce costs of all their space missions. One way to do this is to develop highly efficient upper stage boosters that can be integrated with lower cost Earth to low orbit stages and still place their payloads in to higher orbits. One attractive upper stage is a nuclear bimodal (propulsion and power) engine to accomplished lower booster cost to place space assets in GEO. However this is not being pursued because of DOE's new policy not to fund nuclear space power research and development as well as the difficulty in obtaining launch approval for nuclear propulsion and power systems

  5. Nuclear space power and propulsion requirements and issues

    Swerdling, M. [IR Associates, North Hills, CA (United States); Isenberg, L. [IR Associates, La Habra, CA (United States)

    1995-12-31

    The use of nuclear power in space is going through a low point. The kinds of missions that would use nuclear power are expensive and there are few new expensive missions. Both NASA and DoD are in a mode of cheaper, faster, better, which means using what is available as much as possible and only incorporating new technology to reduce mission cost. NASA is performing Mission to Planet Earth and detailed exploration missions of Mars. These NASA missions can be done with solar-battery power subsystems and there is no need for nuclear power. The NASA mission to Pluto does require nuclear radioisotope power. Ways to reduce the power subsystem cost and the power level are being investigated. NASA is studying ways to explore beyond Mars with solar-battery power because of the cost and uncertainty in the availability and launchability of nuclear space power systems. The DoD missions are all in earth orbit and can be done with solar-battery systems. The major DoD requirement at present is to reduce costs of all their space missions. One way to do this is to develop highly efficient upper stage boosters that can be integrated with lower cost Earth to low orbit stages and still place their payloads in to higher orbits. One attractive upper stage is a nuclear bimodal (propulsion and power) engine to accomplished lower booster cost to place space assets in GEO. However this is not being pursued because of DOE`s new policy not to fund nuclear space power research and development as well as the difficulty in obtaining launch approval for nuclear propulsion and power systems.

  6. Impact loading of a space nuclear powerplant

    Evgeny I. Kraus; Ivan I. Shabalin

    2013-01-01

    Preferred formulation of the problem in two space dimensions are described for solving the three fundamental equations of mechanics (conservation of mass, conservation of momentum, and conservation of energy). Models of the behavior of materials provide the closure to the three fundamentals equations for applications to problems in compressible fluid flow and solid mechanics. Models of fracture and damage are described. A caloric model of the equation of state is proposed to describe thermody...

  7. Nuclear modules for space electric propulsion

    Difilippo, F.C.

    1998-12-31

    Analysis of interplanetary cargo and piloted missions requires calculations of the performances and masses of subsystems to be integrated in a final design. In a preliminary and scoping stage the designer needs to evaluate options iteratively by using fast computer simulations. The Oak Ridge National Laboratory (ORNL) has been involved in the development of models and calculational procedures for the analysis (neutronic and thermal hydraulic) of power sources for nuclear electric propulsion. The nuclear modules will be integrated into the whole simulation of the nuclear electric propulsion system. The vehicles use either a Brayton direct-conversion cycle, using the heated helium from a NERVA-type reactor, or a potassium Rankine cycle, with the working fluid heated on the secondary side of a heat exchanger and lithium on the primary side coming from a fast reactor. Given a set of input conditions, the codes calculate composition. dimensions, volumes, and masses of the core, reflector, control system, pressure vessel, neutron and gamma shields, as well as the thermal hydraulic conditions of the coolant, clad and fuel. Input conditions are power, core life, pressure and temperature of the coolant at the inlet of the core, either the temperature of the coolant at the outlet of the core or the coolant mass flow and the fluences and integrated doses at the cargo area. Using state-of-the-art neutron cross sections and transport codes, a database was created for the neutronic performance of both reactor designs. The free parameters of the models are the moderator/fuel mass ratio for the NERVA reactor and the enrichment and the pitch of the lattice for the fast reactor. Reactivity and energy balance equations are simultaneously solved to find the reactor design. Thermalhydraulic conditions are calculated by solving the one-dimensional versions of the equations of conservation of mass, energy, and momentum with compressible flow. 10 refs., 1 tab.

  8. Progress report on nuclear propulsion for space exploration and science

    Bennett, Gary L.; Miller, Thomas J.

    1993-01-01

    NASA is continuing its work in cooperation with the Department of Energy (DOE) on nuclear propulsion - both nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP). The focus of the NTP studies remains on piloted and cargo missions to Mars (with precursor missions to the moon) although studies are under way to examine the potential uses of NTP for science missions. The focus of the NEP studies has shifted to space science missions with consideration of combining a science mission with an earlier demonstration of NEP using the SP-100 space nuclear reactor power system. Both NTP and NEP efforts are continuing in 1993 to provide a good foundation for science and exploration planners. Both NTP and NEP provide a very important transportation resource and in a number of cases enable missions that could not otherwise be accomplished.

  9. Percolation in finite space. A picture of nuclear fragmentation

    The statistical aspects of cluster distributions as a decisive factor in high energy nuclear fragmentation are studied on a finite lattice model. The qualitative behaviour of the mass spectra is understood in terms of a simple model in which finite space constraints play the main role. Both, the light and the heavy mass sector of the spectrum are derived analytically. In the low density regime the model includes those results of Fisher's condensation theory which are frequently applied to nuclear fragmentation. (orig.)

  10. The MAUS nuclear space reactor with ion propulsion system

    Mainardi, Enrico

    2006-06-01

    MAUS (Moltiplicatore Avanzato Ultracompatto Spaziale) is a nuclear reactor concept design capable to ensure a reliable, long-lasting, low-mass, compact energy supply needed for advanced, future space missions. The exploration of the solar system and the space beyond requires the development of nuclear energy generators for supplying electricity to space-bases, spacecrafts, probes or satellites, as well as for propelling ships in long space missions. For propulsion, the MAUS nuclear reactor could be used to power electric ion drive engines. An ion engine is able to build up to very high velocities, far greater than chemical propulsion systems, but has high power and long service requirements. The MAUS concept is described, together with the ion propulsion engine and together with the reference thermoionic process used to convert the thermal power into electricity. The design work has been performed at the Nuclear Engineering and Energy Conversion Department of the University of Rome "La Sapienza" starting from 1992 on an issue submitted by the Italian Space Agency (ASI), in cooperation with the research laboratories of ENEA.

  11. The MAUS nuclear space reactor with ion propulsion system

    Mainardi, Enrico [DINCE - Dipartimento di Ingegneria Nucleare e Conversioni Energetiche, University of Rome ' La Sapienza' , C.so V. Emanuele II, 244, 00186 Rome (Italy)]. E-mail: mainardi@frascati.enea.it

    2006-06-01

    MAUS (Moltiplicatore Avanzato Ultracompatto Spaziale) is a nuclear reactor concept design capable to ensure a reliable, long-lasting, low-mass, compact energy supply needed for advanced, future space missions. The exploration of the solar system and the space beyond requires the development of nuclear energy generators for supplying electricity to space-bases, spacecrafts, probes or satellites, as well as for propelling ships in long space missions. For propulsion, the MAUS nuclear reactor could be used to power electric ion drive engines. An ion engine is able to build up to very high velocities, far greater than chemical propulsion systems, but has high power and long service requirements. The MAUS concept is described, together with the ion propulsion engine and together with the reference thermoionic process used to convert the thermal power into electricity. The design work has been performed at the Nuclear Engineering and Energy Conversion Department of the University of Rome 'La Sapienza' starting from 1992 on an issue submitted by the Italian Space Agency (ASI), in cooperation with the research laboratories of ENEA.

  12. The Maus nuclear space reactor with ion propulsion system

    Enrico Mainardi [DINCE - Dipartimento di Ingegneria Nucleare e Conversioni Energetiche, University of Rome ' La Sapienza' , C.so V. EmanueleII, 244, 00186 Roma (Italy)

    2006-07-01

    MAUS (Moltiplicatore Avanzato Ultracompatto Spaziale) is a nuclear reactor concept design capable to ensure a reliable, long lasting, low mass, compact energy supply needed for advanced, future space missions. The exploration of the solar system and the space beyond requires the development of nuclear energy generators for supplying electricity to space-bases, spacecrafts, probes or satellites, as well as for propelling ships in long space missions. For propulsion, the MAUS nuclear reactor could be used to power electric ion drive engines. An ion engine is able to build up to very high velocities, far greater than chemical propulsion systems, but has high power and long service requirements. The MAUS concept is described, together with the ion propulsion engine and together with the reference thermionic process used to convert the thermal power into electricity. The design work has been performed at the Nuclear Engineering and Energy Conversion Department of the University of Rome 'La Sapienza' starting from 1992 on an issue submitted by the Italian Space Agency (ASI), in cooperation with the research laboratories of ENEA. (author)

  13. Safety Framework for Nuclear Power Source Applications in Outer Space

    Nuclear power sources (NPS) for use in outer space have been developed and used in space applications where unique mission requirements and constraints on electrical power and thermal management precluded the use of non-nuclear power sources. Such missions have included interplanetary missions to the outer limits of the Solar System, for which solar panels were not suitable as a source of electrical power because of the long duration of these missions at great distances from the Sun. According to current knowledge and capabilities, space NPS are the only viable energy option to power some space missions and significantly enhance others. Several ongoing and foreseeable missions would not be possible without the use of space NPS. Past, present and foreseeable space NPS applications include radioisotope power systems (for example, radioisotope thermoelectric generators and radioisotope heater units) and nuclear reactor systems for power and propulsion. The presence of radioactive materials or nuclear fuels in space NPS and their consequent potential for harm to people and the environment in Earth's biosphere due to an accident require that safety should always be an inherent part of the design and application of space NPS. NPS applications in outer space have unique safety considerations compared with terrestrial applications. Unlike many terrestrial nuclear applications, space applications tend to be used infrequently and their requirements can vary significantly depending upon the specific mission. Mission launch and outer space operational requirements impose size, mass and other space environment limitations not present for many terrestrial nuclear facilities. For some applications, space NPS must operate autonomously at great distances from Earth in harsh environments. Potential accident conditions resulting from launch failures and inadvertent re-entry could expose NPS to extreme physical conditions. These and other unique safety considerations for the use of

  14. Democritos: preparing demonstrators for high power nuclear electric space propulsion

    Masson, Frederic; RUAULT, Jean-Marc; Worms, Jean-Claude; Detsis, Emmanouil; Beaurain, André; Lassoudiere, Francois; Gaia, Enrico; Tosi, Maria -Christina; Jansen, Frank; Bauer, Waldemar; Semenkin, Alexander; Tinsley, Tim; Hodgson, Zara

    2015-01-01

    The Democritos project aims at preparing demonstrators for a megawatt class nuclearelectric space propulsion. It is funded by Horizon 2020, the R&T program of the European Community. It is a new European and Russian project, including as partners: Nuclear National Laboratory (U.K.), DLR (Germany), The Keldysh Research Center (Russia), Thales Alenia Space Italia (Italy), Snecma (France), ESF (France) and CNES (France). IEAV (Brazil) will join as an observer. Democritos is the follo...

  15. Current Development of Nuclear Thermal Propulsion technologies at the Center for Space Nuclear Research

    Robert C. O' Brien; Steven K. Cook; Nathan D. Jerred; Steven D. Howe; Ronald Samborsky; Daniel Brasuell

    2012-09-01

    Nuclear power and propulsion has been considered for space applications since the 1950s. Between 1955 and 1972 the US built and tested over twenty nuclear reactors / rocket engines in the Rover/NERVA programs1. The Aerojet Corporation was the prime contractor for the NERVA program. Modern changes in environmental laws present challenges for the redevelopment of the nuclear rocket. Recent advances in fuel fabrication and testing options indicate that a nuclear rocket with a fuel composition that is significantly different from those of the NERVA project can be engineered; this may be needed to ensure public support and compliance with safety requirements. The Center for Space Nuclear Research (CSNR) is pursuing a number of technologies, modeling and testing processes to further the development of safe, practical and affordable nuclear thermal propulsion systems.

  16. Applicability of trends in nuclear safety analysis to space nuclear power systems

    A survey is presented of some current trends in nuclear safety analysis that may be relevant to space nuclear power systems. This includes: lessons learned from operating power reactor safety and licensing; approaches to the safety design of advanced and novel reactors and facilities; the roles of risk assessment, extremely unlikely accidents, safety goals/targets; and risk-benefit analysis and communication

  17. Disposal of high-level nuclear waste in space

    Coopersmith, Jonathan

    1992-08-01

    A solution of launching high-level nuclear waste into space is suggested. Disposal in space includes solidifying the wastes, embedding them in an explosion-proof vehicle, and launching it into earth orbit, and then into a solar orbit. The benefits of such a system include not only the safe disposal of high-level waste but also the establishment of an infrastructure for large-scale space exploration and development. Particular attention is given to the wide range of technical choices along with the societal, economic, and political factors needed for success.

  18. Impacts of nuclear power sources on space debris

    The paper presents some results of efforts dealing with computational analyses of probability of impact of nuclear power sources (NPS) on space debris (SD), destruction of the NPS structure on the impacts, change in orbital parameters as a result of the NPS impact and reentry. copyright 1997 American Institute of Physics

  19. Safety program considerations for space nuclear reactor systems

    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

  20. Effects of Nuclear Interactions in Space Radiation Transport

    Lin, Zi-Wei; Barghouty, A. F.

    2005-01-01

    Space radiation transport codes have been developed to calculate radiation effects behind materials in human mission to the Moon, Mars or beyond. We study how nuclear fragmentation processes affect predictions from such radiation transport codes. In particular, we investigate the effects of fragmentation cross sections at different energies on fluxes, dose and dose-equivalent from galactic cosmic rays behind typical shielding materials.

  1. Safety program considerations for space nuclear reactor systems

    Cropp, L.O.

    1984-08-01

    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.

  2. Key issues in space nuclear power challenges for the future

    The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems

  3. Communicating with the public: space of nuclear technology

    For two decades the Nuclear and Energy Research Institute (IPEN) has been developing activities for popularization of its R and D activities in the nuclear field. Some of the initiatives already undertaken by IPEN are lectures at schools, guided visits to IPEN facilities, printed informative material, FAQ page in the Web, and displays in annual meetings and technology fairs highlighting its achievements. In order to consolidate these initiatives, IPEN is planning to have a permanent Space of Nuclear Technology (SNT), aiming at introducing students, teachers and the general public to the current applications of nuclear technology in medicine, industry, research, electric power generation, etc. It is intended as an open room to the public and will have a permanent exhibit with historical, scientific, technical and cultural developments of nuclear technology and will also feature temporary exhibitions about specific themes. The space will display scientific material in different forms to allow conducting experiments to demonstrate some of the concepts associated with the properties of nuclear energy, hands-on programs and activities that can be customized to the students' grade level and curriculum. (author)

  4. Communicating with the public: space of nuclear technology

    Maffei, Patricia Martinez; Aquino, Afonso Rodrigues; Gordon, Ana Maria Pinho Leite; Oliveira, Rosana Lagua de; Padua, Rafael Vicente de; Vieira, Martha Marques Ferreira; Vicente, Roberto, E-mail: pmaffei@ipen.br, E-mail: araquino@usp.br, E-mail: amgordon@ipen.br, E-mail: rloliveira@ipen.br, E-mail: rpadua@ipen.br, E-mail: mmvieira@ipen.br, E-mail: rvicente@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    For two decades the Nuclear and Energy Research Institute (IPEN) has been developing activities for popularization of its R and D activities in the nuclear field. Some of the initiatives already undertaken by IPEN are lectures at schools, guided visits to IPEN facilities, printed informative material, FAQ page in the Web, and displays in annual meetings and technology fairs highlighting its achievements. In order to consolidate these initiatives, IPEN is planning to have a permanent Space of Nuclear Technology (SNT), aiming at introducing students, teachers and the general public to the current applications of nuclear technology in medicine, industry, research, electric power generation, etc. It is intended as an open room to the public and will have a permanent exhibit with historical, scientific, technical and cultural developments of nuclear technology and will also feature temporary exhibitions about specific themes. The space will display scientific material in different forms to allow conducting experiments to demonstrate some of the concepts associated with the properties of nuclear energy, hands-on programs and activities that can be customized to the students' grade level and curriculum. (author)

  5. Preserving the nuclear option: The AIAA position paper on space nuclear power

    In response to published reports about the decline in funding for space nuclear power, the Board of Directors of the American Institute of Aeronautics and Astronautics (AIAA) approved a position paper in March 1995 that recommends (1) development and support of an integrated space nuclear power program by DOE, NASA and DoD; (2) Congressional support for the program; (3) advocacy of the program by government and industry leaders; and (4) continuation of cooperation between the U.S. and other countries to advance nuclear power source technology and to promote safety. This position paper has been distributed to various people having oversight of the U.S. space nuclear power program. copyright 1996 American Institute of Physics

  6. Refractory alloy technology for space nuclear power applications

    Purpose of this symposium is twofold: (1) to review and document the status of refractory alloy technology for structural and fuel-cladding applications in space nuclear power systems, and (2) to identify and document the refractory alloy research and development needs for the SP-100 Program in both the short and the long term. In this symposium, an effort was made to recapture the space reactor refractory alloy technology that was cut off in midstream around 1973 when the national space nuclear reactor program began in the early 1960s, was terminated. The six technical areas covered in the program are compatibility, processing and production, welding and component fabrication, mechanical and physical properties, effects of irradiation, and machinability. The refractory alloys considered are niobium, molybdenum, tantalum, and tungsten. Thirteen of the 14 pages have been abstracted separately. The remaining paper summarizes key needs for further R and D on refractory alloys

  7. Refractory alloy technology for space nuclear power applications

    Cooper, R.H. Jr.; Hoffman, E.E. (eds.)

    1984-01-01

    Purpose of this symposium is twofold: (1) to review and document the status of refractory alloy technology for structural and fuel-cladding applications in space nuclear power systems, and (2) to identify and document the refractory alloy research and development needs for the SP-100 Program in both the short and the long term. In this symposium, an effort was made to recapture the space reactor refractory alloy technology that was cut off in midstream around 1973 when the national space nuclear reactor program began in the early 1960s, was terminated. The six technical areas covered in the program are compatibility, processing and production, welding and component fabrication, mechanical and physical properties, effects of irradiation, and machinability. The refractory alloys considered are niobium, molybdenum, tantalum, and tungsten. Thirteen of the 14 pages have been abstracted separately. The remaining paper summarizes key needs for further R and D on refractory alloys. (DLC)

  8. Nuclear Fragmentation Processes Relevant for Human Space Radiation Protection

    Lin, Zi-Wei

    2007-01-01

    Space radiation from cosmic ray particles is one of the main challenges for human space explorations such-as a moon base or a trip to Mars. Models have been developed in order to predict the radiation exposure to astronauts and to evaluate the effectiveness of different shielding materials, and a key ingredient in these models is the physics of nuclear fragmentations. We have developed a semi-analytical method to determine which partial cross sections of nuclear fragmentations most affect the radiation dose behind shielding materials due to exposure to galactic cosmic rays. The cross sections thus determined will require more theoretical and/or experimental studies in order for us to better predict, reduce and mitigate the radiation exposure in human space explorations.

  9. Subcritical space nuclear system without most movable control systems

    This paper describes the design and analysis of advanced space nuclear reactor (ASNR) whose design combines the advantages of radioisotope thermoelectric generator (RTG) and space nuclear reactor (SNR). As opposed to current SNRs designs, ASNR is a subcritical system driven by 232U–Be neutron source to generate thermal power continuously. Most movable control systems in the SNR design are removed. The detailed neutronic calculations by MCNPX (Monte Carlo N-Particle eXtended), including keff, flux, burn-up, loss-ratio of neutron source and immersion reactivity, show that ASNR has higher criticality safety and more compact structure to bear the risk of immersion accident compared with the past SNRs, and the new system can provide more thermal power than RTG. Furthermore, the neutron source efficiency is optimized to improve the utilization of 232U–Be neutron source with the improvement of criticality safety. Compared with the past designs of space nuclear power, ASNR could provide enough thermal power and avoid the occurrence of serious immersion accident in the case of total control system failure. ASNR has potential for future deep space missions. (author)

  10. Nuclear model calculations and their role in space radiation research

    Townsend, L. W.; Cucinotta, F. A.; Heilbronn, L. H.

    2002-01-01

    Proper assessments of spacecraft shielding requirements and concomitant estimates of risk to spacecraft crews from energetic space radiation requires accurate, quantitative methods of characterizing the compositional changes in these radiation fields as they pass through thick absorbers. These quantitative methods are also needed for characterizing accelerator beams used in space radiobiology studies. Because of the impracticality/impossibility of measuring these altered radiation fields inside critical internal body organs of biological test specimens and humans, computational methods rather than direct measurements must be used. Since composition changes in the fields arise from nuclear interaction processes (elastic, inelastic and breakup), knowledge of the appropriate cross sections and spectra must be available. Experiments alone cannot provide the necessary cross section and secondary particle (neutron and charged particle) spectral data because of the large number of nuclear species and wide range of energies involved in space radiation research. Hence, nuclear models are needed. In this paper current methods of predicting total and absorption cross sections and secondary particle (neutrons and ions) yields and spectra for space radiation protection analyses are reviewed. Model shortcomings are discussed and future needs presented. c2002 COSPAR. Published by Elsevier Science Ltd. All right reserved.

  11. Nuclear Thermal Rocket - An Established Space Propulsion Technology

    Klein, Milton

    2004-02-01

    From the late 1950s to the early 1970s a major program successfully developed the capability to conduct space exploration using the advanced technology of nuclear rocket propulsion. The program had two primary elements: pioneering and advanced technology work-Rover-at Los Alamos National Laboratory and its contractors provided the basic reactor design, fuel materials development, and reactor testing capability; and engine development-NERVA-by the industrial team of Aerojet and Westinghouse building on and extending the Los Alamos efforts to flight system development. This presentation describes the NERVA program, the engine system testing that demonstrated the space-practical operation capabilities of nuclear thermal rockets, and the mission studies that point the way to most effectively use the NTR capabilities. Together, the two programs established a technology base that includes proven NTR capabilities of (1) over twice the specific impulse of chemical propulsion systems, (2) thrust capabilities ranging from 44kN to 1112kN, and (3) practical thrust-to-weight ratios for future NASA space exploration missions, both manned payloads to Mars and unmanned payloads to the outer planets. The overall nuclear rocket program had a unique management structure that integrated the efforts of the two government agencies involved-NASA and the then-existing Atomic Energy Commission. The objective of this paper is to summarize and convey the technical and management lessons learned in this program as the nation considers the design of its future space exploration activities.

  12. Multimegawatt space nuclear power supply, Phase 1 Final report

    1989-02-17

    This Specification establishes the performance, design, development, and test requirements for the Boeing Multimegawatt Space Nuclear Power System (MSNPS). The Boeing Multimegawatt Space Power System is part of the DOE/SDIO Multimegawatt Space Nuclear Power Program. The purpose of this program is to provide a space-based nuclear power system to meet the needs of SDIO missions. The Boeing MSNPS is a category 1 concept which is capable of delivering 10's of MW(e) for 100's of seconds with effluent permitted. A design goal is for the system to have growth or downscale capability for other power system concepts. The growth objective is to meet the category 3 capability of 100's of MW(e) for 100's of seconds, also with effluent permitted. The purpose of this preliminary document is to guide the conceptual design effort throughout the Phase 1 study effort. This document will be updated through out the study. It will thus result in a record of the development of the design effort.

  13. Applications of nuclear-powered thermoelectric generators in space

    The source of electrical power which enables information to be transmitted from the space crafts Voyager 1 and 2 back to Earth after a time period of more than a decade and at a distance of more than a billion miles is known as an RTG (radioisotope thermoelectric generator). It utilises the Seebeck effect in producing electricity from heat. In essence it consists of a large number of semiconductor thermocouples connected electrically in series and thermally in parallel. A temperature difference is maintained across the thermocouples by providing a heat source, which in the case of an RTG is a radioactive isotope, and the heat sink is space. The combination of an energy-conversion system, free of moving parts and a long-life, high energy-density heat source, provides a supply of electrical power typically in the range of tens to hundred of watts and which operates reliably over extended periods of time. An electric power source, based upon thermoelectric conversion by which utilises a nuclear reactor as a heat source, has also been deployed in space and a 100-kW system is being developed to provide electrical power to a variety of commercial and military projects including SDI. Developments in thermoelectrics that have taken place in the western world during the past 30 years are primarily due to United States interest and involvement in the exploration of space. This paper reviews US applications of nuclear-powered thermoelectric generators in space. (author)

  14. A Review of Tribomaterial Technology for Space Nuclear Power Systems

    Stanford, Malcolm K.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) has recently proposed a nuclear closed-cycle electric power conversion system for generation of 100-kW of electrical power for space exploration missions. A critical issue is the tribological performance of sliding components within the power conversion unit that will be exposed to neutron radiation. This paper presents a review of the main considerations that have been made in the selection of solid lubricants for similar applications in the past as well as a recommendations for continuing development of the technology.

  15. Refractory metal-matrix composites for space nuclear power applications

    Space nuclear power systems for SDI will require materials that have excellent high specific strength and creep resistance at high temperature, are compatible with space environmental conditions, and the heat transfer fluids of power conversion systems, and stable at high neutron fluence in extended operation. The development of composite components composed of continuous high strength tungsten alloy filaments in a ductile refractory metal alloy matrix is a logical next step in the progression of high temperature structural materials to meet these requirements. The basis for this technology advance is the extraordinary high temperature strength and recrystallization resistance of a class of tungsten alloys containing small quantities of hafnium carbide

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

    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)

  17. Molybdenum-rhenium alloy development for space nuclear power applications

    Refractory metals and refractory metal alloys are essential to the development of advanced nuclear reactor systems for space power applications because of the anticipated high operating temperatures of these systems. The refractory metals and alloys based on niobium, molybdenum, tantalum and tungsten are being considered for use in these systems because of their high temperature capabilities and compatibility with alkali metals. Molybdenum-base alloys offer many advantages in these systems, but their brittleness at low temperatures serves as a major deterrent to their use. Molybdenum-rhenium alloys with 11-13 wt% rhenium have been found to possess good low temperature ductility that results from the solution softening process in this alloy system. The development of solution softened molybdenum-rhenium alloys for use in space nuclear power applications is in progress at the Los Alamos National Laboratory, and this paper presents a review and update of this work

  18. Nuclear Waste Disposal in Space: BEP's Best Hope?

    Coopersmith, Jonathan

    2006-05-01

    The best technology is worthless if it cannot find a market Beam energy propulsion (BEP) is a very promising technology, but faces major competition from less capable but fully developed conventional rockets. Rockets can easily handle projected markets for payloads into space. Without a new, huge demand for launch capability, BEP is unlikely to gain the resources it needs for development and application. Launching tens of thousands of tons of nuclear waste into space for safe and permanent disposal will provide that necessary demand while solving a major problem on earth. Several options exist to dispose of nuclear waste, including solar orbit, lunar orbit, soft lunar landing, launching outside the solar system, and launching into the sun.

  19. Nuclear pairing within a configuration-space Monte Carlo approach

    Lingle, Mark; Volya, Alexander

    2015-06-01

    Pairing correlations in nuclei play a decisive role in determining nuclear drip lines, binding energies, and many collective properties. In this work a new configuration-space Monte Carlo (CSMC) method for treating nuclear pairing correlations is developed, implemented, and demonstrated. In CSMC the Hamiltonian matrix is stochastically generated in Krylov subspace, resulting in the Monte Carlo version of Lanczos-like diagonalization. The advantages of this approach over other techniques are discussed; the absence of the fermionic sign problem, probabilistic interpretation of quantum-mechanical amplitudes, and ability to handle truly large-scale problems with defined precision and error control are noteworthy merits of CSMC. The features of our CSMC approach are shown using models and realistic examples. Special attention is given to difficult limits: situations with nonconstant pairing strengths, cases with nearly degenerate excited states, limits when pairing correlations in finite systems are weak, and problems when the relevant configuration space is large.

  20. Nuclear Waste Disposal in Space: BEP's Best Hope?

    The best technology is worthless if it cannot find a market Beam energy propulsion (BEP) is a very promising technology, but faces major competition from less capable but fully developed conventional rockets. Rockets can easily handle projected markets for payloads into space. Without a new, huge demand for launch capability, BEP is unlikely to gain the resources it needs for development and application. Launching tens of thousands of tons of nuclear waste into space for safe and permanent disposal will provide that necessary demand while solving a major problem on earth. Several options exist to dispose of nuclear waste, including solar orbit, lunar orbit, soft lunar landing, launching outside the solar system, and launching into the sun

  1. Spacing grid for a nuclear fuel sub-assembly

    The description is given of a fuel pin spacing grid for a nuclear fuel sub-assembly. The grid includes several strips shaped to form a hexagonal honeycomb cell assembly. The cells are of one piece construction, each cell being formed from an individual strip. Every other side of the cell has an opening, the other sides being continuous. Each continuous side includes a shaped part acting as guide for a fuel pin

  2. Lightweight Radiator for in Space Nuclear Electric Propulsion

    Craven, Paul; Tomboulian, Briana; SanSoucie, Michael

    2014-01-01

    Nuclear electric propulsion (NEP) is a promising option for high-speed in-space travel due to the high energy density of nuclear fission power sources and efficient electric thrusters. Advanced power conversion technologies may require high operating temperatures and would benefit from lightweight radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Game-changing propulsion systems are often enabled by novel designs using advanced materials. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature, thermal conductivity, and mass. These properties combine to allow advances in operational efficiency and high temperature feasibility. An effort at the NASA Marshall Space Flight Center to show that woven high thermal conductivity carbon fiber mats can be used to replace standard metal and composite radiator fins to dissipate waste heat from NEP systems is ongoing. The goals of this effort are to demonstrate a proof of concept, to show that a significant improvement of specific power (power/mass) can be achieved, and to develop a thermal model with predictive capabilities making use of constrained input parameter space. A description of this effort is presented.

  3. Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative

    Marshall, Albert C.; Lee, James H.; Mcculloch, William H.; Sawyer, J. Charles, Jr.; Bari, Robert A.; Cullingford, Hatice S.; Hardy, Alva C.; Niederauer, George F.; Remp, Kerry; Rice, John W.

    1993-01-01

    An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations.

  4. Review of Nuclear Physics Experiments for Space Radiation

    Norbury, John W.; Miller, Jack; Adamczyk, Anne M.; Heilbronn, Lawrence H.; Townsend, Lawrence W.; Blattnig, Steve R.; Norman, Ryan B.; Guetersloh, Stephen B.; Zeitlin, Cary J.

    2011-01-01

    Human space flight requires protecting astronauts from the harmful effects of space radiation. The availability of measured nuclear cross section data needed for these studies is reviewed in the present paper. The energy range of interest for radiation protection is approximately 100 MeV/n to 10 GeV/n. The majority of data are for projectile fragmentation partial and total cross sections, including both charge changing and isotopic cross sections. The cross section data are organized into categories which include charge changing, elemental, isotopic for total, single and double differential with respect to momentum, energy and angle. Gaps in the data relevant to space radiation protection are discussed and recommendations for future experiments are made.

  5. Overview of materials technologies for space nuclear power and propulsion

    Zinkle, S. J.; Ott, L. J.; Ingersoll, D. T.; Ellis, R. J.; Grossbeck, M. L.

    2002-01-01

    A wide range of different space nuclear systems are currently being evaluated as part of the DOE Special Purpose Fission Technology program. The near-term subset of systems scheduled to be evaluated range from 50 kWe gas-, pumped liquid metal-, or liquid metal heat pipe-cooled reactors for space propulsion to 3 kWe heat pipe or pumped liquid metal systems for Mars surface power applications. The current status of the materials technologies required for the successful development of near-term space nuclear power and propulsion systems is reviewed. Materials examined in this overview include fuels (UN, UO2, UZrH), cladding and structural materials (stainless steel, superalloys, refractory alloys), neutron reflector materials (Be, BeO), and neutron shield materials (B4C,LiH). The materials technologies issues are considerably less demanding for the 3 kWe reactor systems due to lower operating temperatures, lower fuel burnup, and lower radiation damage levels. A few reactor subcomponents in the 3 kWe reactors under evaluation are being used near or above their engineering limits, which may adversely affect the 5 to 10 year lifetime design goal. It appears that most of these issues for the 3 kWe reactor systems can be accommodated by incorporating a few engineering design changes. Design limits (temperature, burnup, stress, radiation levels) for the various materials proposed for space nuclear reactors will be summarized. For example, the temperature and stress limits for Type 316 stainless steel in the 3 kWe Na-cooled heat pipe reactor (Stirling engine) concept will be controlled by thermal creep and CO2 corrosion considerations rather than radiation damage issues. Conversely, the lower operating temperature limit for the LiH shield material will likely be defined by ionizing radiation damage (radiolysis)-induced swelling, even for the relatively low radiation doses associated with the 3 kWe reactor. .

  6. Nuclear safety, legal aspects and policy recommendations for space nuclear power and propulsion systems

    Lenard, Roger X.

    2006-07-01

    This paper represents a chapter of the International Astronautical Academy's Cosmic Study on safety, legal and policy aspects of advanced (specifically nuclear) power and propulsions systems; it is divided into several sections. The first section covers a series of findings and develops a set of recommendations for operations of space reactor systems in a safe, environmentally compliant fashion. The second section develops a generic set of hazard scenarios that might be experienced by a space nuclear system with emphasis on different methods under which such a system could be engaged, such as surface power, in-space nuclear electric or nuclear thermal propulsion. The third section develops these into test and analysis efforts that would likely be conducted. Risk areas with engineering judgment set toward frequency and consequences. The fourth section identifies what probable technology limits might be experienced by nuclear propulsion systems and the exploration limitations these technology restrictions might impose. Where the IAA recommends a change, the IAA leadership should be prepared to work with national and international bodies to implement the desired modifications.

  7. Fuels for space nuclear power systems. 1. Tri-Carbide Nuclear Fuel Processing and Characterization for Space Nuclear Applications

    Tri-carbide fuels fabricated from uranium and refractory metal carbides have been proposed for advanced nuclear thermal propulsion (NTP) applications. These fuels are particularly desirable for space nuclear applications because of their high melting points and high thermal conductivity and their thermochemical stability with the flowing hot hydrogen propellant. This study examined the processing methods for fabricating low-porosity, single-phase solid-solution tri-carbides of (U, Zr,Nb)C. Binary carbides of (U, Zr)C for NTP were first studied at the end of the Rover/NERVA program, a joint effort between the National Aeronautics and Space Administration (NASA) and the Atomic Energy Commission from 1955 to 1973. This advanced fuel was proposed to reduce the mass losses experienced by earlier graphite matrix and composite fuels due to corrosion by the flowing hot hydrogen propellant. However, insufficient tests were completed before the program was canceled in 1973. Results of this study revealed the difficulty to extrude this very hard material in the desired geometry for NTP applications and a susceptibility to fracture during operation. Preliminary indication of higher melting points and improvements in thermochemical stability led to work on tri-carbides of (U, Zr,Nb)C and (U, Zr, Ta)C in the former Soviet Union. A joint effort with the Russian research institute LUTCH and INSPI from 1993 to 1997 studied the mass losses from these fuels, which were extruded in a simple, twisted-ribbon geometry compatible with Russian core designs. The melting temperature of the tri-carbides is influenced by the carbon-to-metal ratio (C/M) and the uranium metal mole fraction (U/M).A target C/M of 0.88 to 0.95 was maintained during the Rover/NERVA program to avoid the development of a second phase, carbon, which leads to significantly lower, eutectic, melting temperatures. Recent efforts at INSPI have been directed toward optimizing the processing methods and parameters for

  8. RADCONTAB 1.0: a look-up tables tool for radiological assessment of contaminated land on Nuclear Licensed sites

    This note describes a simple electronic spreadsheet 'look-up tables' tool (RADCONTAB version 1.0), developed by British Nuclear Fuels plc (BNFL) to facilitate the radiological assessment of land affected by existing 'historic' radioactive contamination on UK Nuclear Licensed sites. The specification and design of the tool have been subject to open consultation and peer review. The tool with accompanying guide is now freely available on the internet. (note)

  9. Space Nuclear Thermal Propulsion Nuclear Element Tests at Sandia National Laboratories

    Nuclear Element Tests (NET) are being performed as part of the U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) Program to evaluate high performance fuel elements intended for use in future nuclear propulsion systems. The NET experiments are to be performed at the Sandia National Laboratories (SNL's) Annular Core Research Reactor (ACRR). Objectives of these experiments are to provide engineering validation and demonstration of critical-fuel-element-related technologies and an experimental data base to support analytical design methods for the SNTP Program. Currently, hardware for the first two fueled NET experiments has been fabricated, and cold flow tests have been accomplished with a representative set of hardware to assure the experimental capability to achieve test objectives in-reactor. Assembly of the first NET experiment to test a representative nuclear fuel element is in progress, and planned operational sequences have been defined

  10. Development of NERVA reactor for space nuclear propulsion

    The general technology development and demonstration of a Nuclear Engine for Rocket Vehicle Application (NERVA), a joint AEC-NASA program, was undertaken successfully in the 1960's and terminated in 1971 for lack of a specific mission. Detailed flight engine specifications were defined and several candidate designs which would satisfy these specifications were completed just prior to termination of these efforts. However, the technology interest continued and efforts were extended during the early 1970's to consider space power applications including a manned Mars mission and dual mode (propulsion power and electrical power) operation. Subsequent efforts have continued in developing electric power applications. Light-weight solid core reactor nuclear power sources have been conceptually studied based upon this technology. This paper provides a short summary of the technology that evolved in this very complex and frequently changing program with some specific references to the Mars mission propulsion application as it evolved from the NERVA development program

  11. Nuclear fragmentation measurements for hadrontherapy and space radiation protection

    De Napoli, M. [INFN - Sezione di Catania (Italy); Agodi, C.; Blancato, A. A.; Cavallaro, M.; Cirrone, G. A. P.; Cuttone, G.; Sardina, D.; Scuderi, V. [INFN - Laboratori Nazionali del Sud (Italy); Battistoni, G. [INFN - Sezione di Milano (Italy); Bondi, M.; Cappuzzello, F.; Carbone, D.; Nicolosi, D.; Raciti, G.; Tropea, S. [INFN - Laboratori Nazionali del Sud, Italy and Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania (Italy); Giacoppo, F. [Department of Physics, University of Oslo (Norway); Morone, M. C. [Dipartimento di Biopatologia e Diagnostica per Immagini, Universita di Roma Tor Vergata (Italy); Pandola, L. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Rapisarda, E. [Nuclear and Radiation Physics Section, Katholieke Universiteit Leuven Celestijnenlaan Heverlee (Belgium); Romano, F. [INFN - Laboratori Nazionali del Sud (Italy) and Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi Roma (Italy); and others

    2013-04-19

    Nuclear fragmentation measurements are necessary in hadrontherapy and space radiation protection, to predict the effects of the ion nuclear interactions within the human body. Nowadays, a very limited set of carbon fragmentation cross sections has been measured and in particular, to our knowledge, no double differential fragmentation cross sections at intermediate energies are available in literature. We have measured the double differential cross sections and the angular distributions of the secondary fragments produced in the {sup 12}C fragmentation at 62 AMeV on a thin carbon target. The experimental data have been also used to benchmark the prediction capability of the Geant4 Monte Carlo code at intermediate energies, where it was never tested before.

  12. Space nuclear reactor SP-100 thermal-hydraulic simulation

    Since 1983 it has been under development in the USA the project SP-100 of space nuclear reactors for electric generation in a range of 100 to 1000 KWe. In this project the heat is generated at the core of a fast compact liquid lithium refrigerated reactor. Thermoelectric converters produce direct current electric energy and the primary and secondary loops flow is controlled by electromagnetic thermoelectric pumps (EMTE). In this work it is studied a system with a fast nuclear reactor, with similar characteristics to the SP-100, aiming at generating high electric power in space for a future application on the TERRA (Advanced Fast Reactor Technology) Project of IEAv (Institute for Advanced Studies). It will be presented the working principles, basic structure and operation characteristics of an electromagnetic thermoelectric pump (EMTE) for a liquid metal cooled nuclear reactor refrigeration loops flow control. In order to determine the operating point of the reactor, it is indispensable the simulation of the EMTE pump along with the other components of the system, once all the working parameters are connected. So, it has been developed a computer system, named BEMTE-3 (a FORTRAN micro-computer code), which simulates the primary and secondary refrigeration components of liquid metal cooled fast space reactor. This computer code also simulates the thermoelectric conversion, with the flow being controlled by the EMTE pump with thermoelectric converters, determining the system operation point for a given nominal operating power. The BEMTE-3 is used for the study of the SP-100 primary and secondary loops thermal-hydraulic simulation and for the calculation of the operating point of the system based on data from available projects. (author)

  13. Thermo-magnetic systems for space nuclear reactors an introduction

    Maidana, Carlos O

    2014-01-01

    Introduces the reader to engineering magnetohydrodynamics applications and presents a comprehensive guide of how to approach different problems found in this multidisciplinary field. An introduction to engineering magnetohydrodynamics, this brief focuses heavily on the design of thermo-magnetic systems for liquid metals, with emphasis on the design of electromagnetic annular linear induction pumps for space nuclear reactors. Alloy systems that are liquid at room temperature have a high degree of thermal conductivity far superior to ordinary non-metallic liquids. This results in their use for

  14. Static and dynamic high power, space nuclear electric generating systems

    Space nuclear electric generating systems concepts have been assessed for their potential in satisfying future spacecraft high power (several megawatt) requirements. Conceptual designs have been prepared for reactor power systems using the most promising static (thermionic) and the most promising dynamic conversion processes. Component and system layouts, along with system mass and envelope requirements have been made. Key development problems have been identified and the impact of the conversion process selection upon thermal management and upon system and vehicle configuration is addressed. 10 references

  15. Probabilistic assessment of space nuclear propulsion system nozzle

    Shah, Ashwin R.; Ball, Richard D.; Chamis, Christos C.

    1994-01-01

    In assessing the reliability of a space nuclear propulsion system (SNPS) nozzle, uncertainties associated with the following design parameters were considered: geometry, boundary conditions, material behavior, and thermal and pressure loads. A preliminary assessment of the reliability was performed using NESSUS (Numerical Evaluation of Stochastic Structures Under Stress), a finite-element computer code developed at the NASA Lewis Research Center. The sensitivity of the nozzle reliability to the uncertainties in the random variables was quantified. With respect to the effective stress, preliminary results showed that the nozzle spatial geometry uncertainties have the most significant effect at low probabilities whereas the inner wall temperature has the most significant effect at higher probabilities.

  16. Space Agriculture for Recovery of Fukushima from the Nuclear Disaster

    Yamashita, Masamichi; Tomita-Yokotani, Kaori; Hasegawa, Katsuya; Kanazawa, Shinjiro; Oshima, Tairo

    2012-07-01

    Space agriculture is an engineering challenge to realize life support functions on distant planetary bodies under their harsh environment. After the nuclear disaster in Fukushima, its land was heavily contaminated by radioactive cesium and other nuclei. We proposed the use of space agriculture to remediate the contaminated land. Since materials circulation in the human dominant system should remove sodium from metabolic waste at processing fertilizer for crop plants, handling of sodium and potassium ions in agro-ecosystem has been one of major research targets of space agriculture. Cesium resembles to potassium as alkaline metal. Knowledge on behavior of sodium/potassium in agro-ecosystem might contribute to Fukushima. Reduction of volume of contaminated biomass made by hyperthermophilic aerobic composting bacterial system is another proposal from space agriculture. Volume and mass of plant bodies should be reduced for safe storage of nuclear wastes. Capacity of the storage facility will be definitely limited against huge amount of contaminated soil, plants and others. For this purpose, incineration of biomass first choice. The process should be under the lowered combustion temperature and with filters to confine radioactive ash to prevent dispersion of radioactive cesium. Biological combustion made by hyperthermophilic aerobic composting bacterial system might offer safe alternative for the volume reduction of plant biomass. Scientific evidence are demanded for Fukushima in order to to judge health risks of the low dose rate exposure and their biological mechanism. Biology and medicine for low dose rate exposure have been intensively studied for space exploration. The criteria of radiation exposure for general public should be remained as 1 mSv/year, because people has no merit at being exposed. However, the criteria of 1,200 mSv for life long, which is set to male astronaut, age of his first flight after age 40, might be informative to people for understanding

  17. Creep properties of refractory alloys for space nuclear power applications

    To satisfy power, mass, and volume requirements, space nuclear power systems are designed with refractory alloys for fuel cladding and reactor structures. This paper presents analysis of existing and new creep data for the refractory alloys that are candidates for fuel cladding or reactor structural applications for space power reactors. Analysis includes use of empirical parameters such as Larson-Miller, Dorn, Orr-Sherby-Dorn, and Manson-Haferd to predict long-term creep properties with data from relatively short-term tests. References curves for stress to produce 1% creep strain in 7 years versus these parameters are presented for Nb-1% Zr, PWC-11, Mo-11 and 14% Re, T-111, ASTAR-811C, CVD-W, W-5% Re, and W-25% Re

  18. CVD refractory metals and alloys for space nuclear power application

    CVD technology has made significant contributions to the development of space nuclear power systems during the period 1962 to 1972. For the in-core thermionic concept, CVD technology is essential to the fabrication of the tungsten electron emitter. For the liquid metal cooled fuel pin using uranium nitride as fuel and T-111 and Nb-1 Zr as cladding, a tungsten barrier possibly produced by CVD methods is essential to the fuel-cladding compatibility at the designed operating temperature. Space power reactors may use heat pipes to transfer heat from the reactor core to the conversion system. CVD technology has been used for fabricating the heat pipe used as cross-flow heat exchanger, including the built-in channels on the condenser wall for liquid lithium return. 28 references, 17 figures

  19. An Approach to Autonomous Control for Space Nuclear Power Systems

    Wood, Richard Thomas [ORNL; Upadhyaya, Belle R. [University of Tennessee, Knoxville (UTK)

    2011-01-01

    Under Project Prometheus, the National Aeronautics and Space Administration (NASA) investigated deep space missions that would utilize space nuclear power systems (SNPSs) to provide energy for propulsion and spacecraft power. The initial study involved the Jupiter Icy Moons Orbiter (JIMO), which was proposed to conduct in-depth studies of three Jovian moons. Current radioisotope thermoelectric generator (RTG) and solar power systems cannot meet expected mission power demands, which include propulsion, scientific instrument packages, and communications. Historically, RTGs have provided long-lived, highly reliable, low-power-level systems. Solar power systems can provide much greater levels of power, but power density levels decrease dramatically at {approx} 1.5 astronomical units (AU) and beyond. Alternatively, an SNPS can supply high-sustained power for space applications that is both reliable and mass efficient. Terrestrial nuclear reactors employ varying degrees of human control and decision-making for operations and benefit from periodic human interaction for maintenance. In contrast, the control system of an SNPS must be able to provide continuous operatio for the mission duration with limited immediate human interaction and no opportunity for hardware maintenance or sensor calibration. In effect, the SNPS control system must be able to independently operate the power plant while maintaining power production even when subject to off-normal events and component failure. This capability is critical because it will not be possible to rely upon continuous, immediate human interaction for control due to communications delays and periods of planetary occlusion. In addition, uncertainties, rare events, and component degradation combine with the aforementioned inaccessibility and unattended operation to pose unique challenges that an SNPS control system must accommodate. Autonomous control is needed to address these challenges and optimize the reactor control design.

  20. Combined-Brayton cycle, space nuclear power systems

    Because it is a widely recognized dynamic space conversion system, the Brayton cycle has been studied in France since several years, especially within the framework of a limited space program. A recuperated cycle of 20 to 30 kWe has been considered so far. However, possible applications could evolve and the need for an extended, diversified utilization of the Brayton cycle could appear. So, for Lunar or Mars bases which would accept large radiators and can benefit from a certain gravity level, combined cycle systems could be proposed. Following a reference to past works on space combined cycles, a possible association of a Brayton cycle with a thermoionic reactor is presented. The power level of a 'Topaz-2' type space nuclear system can be boosted from 8 kWe to around 36 to 53 kWe, at the expense of a large radiator of course. Furthermore, combined Brayton-Rankine, organic (toluene) or steam, cycles can pave the way to a simpler gas-cooled, particle bed reactor concept. A particular arrangement of HeXe heater and boiler or steam generator in series is proposed. It makes it possible to lower the reactor inlet temperature, which is quite adequate for the use of light water as moderator. Oustanding net efficiencies of 25.8 to 27.6 per cent, given the reactor temperature profile, are obtained. Consequences on the reactor design are mentioned

  1. Neutronic data in support of space nuclear propulsion

    Mughabghab, S.; Schmidt, E.; Ludewig, H.

    1997-07-01

    The thermophysical properties of lithium hydride ({sup 7}LiH), particularly small density (0.775 gm/cc), high melting point (688 C) and relatively high hydrogen atomic number density makes it an attractive material for use as a neutron moderator and shield (for LiH) in space nuclear thermal propulsion. However, the unavailability of neutronic cross section data in the thermal energy range for {sup 7}LiH in the ENDF/B library necessitated the generation of the relevant data which is required in criticality studies and for the determination of temperature-dependent feedback coefficients in the moderator and fuel regions. Here, the scattering kernel data for {sup 7}LiH have been generated for the first time in the temperature range 50--1,000 K. This is based on a phonon distribution function derived from both experimental data and theoretical calculations. A detailed study of the variation of the moderator temperature coefficient {alpha}{sub m}(T) with temperature, T, is carried out for a typical space nuclear reactor of the particle bed type. It is established that the moderator temperature coefficient is proportional to T{sup {minus}1.65} where T is the moderator temperature in Kelvin units.

  2. Technology development for nuclear power generation for space application

    For a few years now, the TERRA project is developing several technology pieces to foster nuclear space applications. In this way, a nuclear reactor concept has been developed as a first proposal. Together, the problem of heat to electricity conversion has been addressed. A closed Brayton cycle is being built and a Stirling machine is being worked out and perfected. In addition, two types of heat pipes are being look at. One related with high temperature made of Mo13Re, an especial alloy. And a second one made of copper, which mainly could be used as a passive heat rejection. In this way, all major areas of interest in a micro station to be used in space has been addressed. A new passive technology has been inferred and is related with Tesla turbine or its evolution, known as multi fluid passive turbine. This technology has the potential to either: improve the Brayton cycle or its efficiency. In this paper, some details are discussed and some will be shown during the presentation, as the work evolve. (author)

  3. Technology development for nuclear power generation for space application

    Guimaraes, Lamartine N.F.; Ribeiro, Guilherme B.; Braz Filho, Francisco A.; Nascimento, Jamil A.; Placco, Guilherme M., E-mail: guimarae@ieav.cta.br, E-mail: lamartine.guimaraes@pq.cnpq.br [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil). Divisao de Energia Nuclear; Faria, Saulo M. de [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil)

    2015-07-01

    For a few years now, the TERRA project is developing several technology pieces to foster nuclear space applications. In this way, a nuclear reactor concept has been developed as a first proposal. Together, the problem of heat to electricity conversion has been addressed. A closed Brayton cycle is being built and a Stirling machine is being worked out and perfected. In addition, two types of heat pipes are being look at. One related with high temperature made of Mo13Re, an especial alloy. And a second one made of copper, which mainly could be used as a passive heat rejection. In this way, all major areas of interest in a micro station to be used in space has been addressed. A new passive technology has been inferred and is related with Tesla turbine or its evolution, known as multi fluid passive turbine. This technology has the potential to either: improve the Brayton cycle or its efficiency. In this paper, some details are discussed and some will be shown during the presentation, as the work evolve. (author)

  4. Power conversion for a microreactor: a nuclear space application

    Generating nuclear power in space is of fundamental importance if it is desired to realize some aggressive type of exploration. Basically, at Earth orbit (either LEO or GEO) most applications tend to use solar panels, which are just fine, in spite of problems such as vibration, non optimal light incidence angle and non electricity generation due to Earth's shadow. For deep space exploration the nuclear power is been considered as a strong candidate and maybe the only one. The Institute for Advanced Studies is conducting the TERRA project that tracks the developments in the area and, also, intends to develop the key technologies that will allow such a machine to be build with indigenous technology. TERRA stands for TEcnologia de Reatores Rapidos Avancados. This project, at its first stage aims at the specification of the microreactor fuel element with its possible geometrical arrangements. Also for this stage a gas Brayton closed cycle is being considered as a heat conversion to electricity and/or propulsion effect. The basic idea is to adapt an open loop aeronautic gas turbine to operate as a closed loop gas Turbine. This arrangement will use heat pipes as a cold source, or a heat rejection passive system. Up to this point a lot has been done in terms of numerical and graphical development. It is expected that some built up will be happening during this year. An account of this work will be presented at the conference. (author)

  5. Potential civil mission applications for space nuclear power systems

    The modest energy needs of spacecraft over the last twenty-five years have been met by photovoltaic arrays with batteries, primary fuel cells, and radioisotope thermoelectric generators (RTG). Although these energy sources have been adequate in the past, the next generation of space missions will place requirements on energy systems that might be difficult to satisfy with these currently utilized technologies. The extent of future space exploration could very well be limited by the cost and difficulty of supplying energy to the spacecraft unless advanced technologies are developed. A number of applications studies have emphasized the need for a lighter, cheaper, and more compact high-energy source than the scaling up of current technologies would permit (Angelo and Buden 1981). A nuclear reactor power system has the potential of satisfying these requirements. The joint NASA/DOD/DOE SP-100 program has been initiated to explore and evaluate this option and to develop critical elements of the technology. The major thrust of the program at the outset is aimed at space reactor systems of the 100 kW class

  6. Overview of CNES-CEA joint program on space nuclear Brayton systems

    In this paper French studies on 20-kWe space nuclear power systems are presented. The gas-cooled reactor nuclear systems, some investigations on advanced thermal neutron spectrum systems, a support work on materials, parameters optimization and operating transient analysis, and Brayton cycle-thermoelectric and nuclear-non nuclear systems comparisons

  7. Nuclear electric propulsion for future NASA space science missions

    Yen, Chen-wan L.

    1993-07-20

    This study has been made to assess the needs, potential benefits and the applicability of early (circa year 2000) Nuclear Electric Propulsion (NEP) technology in conducting NASA science missions. The study goals are: to obtain the performance characteristics of near term NEP technologies; to measure the performance potential of NEP for important OSSA missions; to compare NEP performance with that of conventional chemical propulsion; to identify key NEP system requirements; to clarify and depict the degree of importance NEP might have in advancing NASA space science goals; and to disseminate the results in a format useful to both NEP users and technology developers. This is a mission performance study and precludes investigations of multitudes of new mission operation and systems design issues attendant in a NEP flight.

  8. Shielding considerations for advanced space nuclear reactor systems

    To meet the anticipated future space power needs, the Los Alamos National Laboratory is developing components for a compact, 100 kW/sub e/-class heat pipe nuclear reactor. The reactor uses uranium dioxide (UO2) as its fuel, and is designed to operate around 1500 k. Heat pipes are used to remove thermal energy from the core without the use of pumps or compressors. The reactor heat pipes transfer mal energy to thermoelectric conversion elements that are advanced versions of the converters used on the enormously successful Voyager missions to the outer planets. Advanced versions of this heat pipe reactor could also be used to provide megawatt-level power plants. The paper reviews the status of this advanced heat pipe reactor and explores the radiation environments and shielding requirements for representative manned and unmanned applications

  9. Cyclic gaseous core reactors for space nuclear power applications

    Extensive theoretical-experimental investigations have been performed at the University of Florida on cyclic gaseous core reactors. Neutronics-energetics analyses have led to a basic scientific understanding of the behavior associated with conceptual operation of these devices. Thermal-physical properties studies have resulted in the identification of desirable working fluids and UF6-materials interaction studies have identified a number of potential problems as well as corresponding potential solutions. The results of these research efforts indicate that the cyclic gaseous core reactor is a versatile and promising nuclear energy concept that has attractive features for space power generation. These include low critical mass, high fuel utilization, high output temperature and good thermal efficiency, wide operating ranges, excellent control and safety characteristics, and adaptability to a wide variety of different energy conversion systems

  10. Liquid metal coolants for space nuclear power units

    The consideration is given to the results of investigations conducting in IPPE from the 1950s on the technology and heat transfer of liquid metal coolants (lithium and sodium-potassium eutectic alloy) of space nuclear power plants (SNPP). The advantage of lithium coolant is its low density, splendid heat-transfer properties, high boiling point, low saturated vapor pressure, low activation when passing through reactor core, etc. Its disadvantage is high melting point and the higher corrosion activity than sodium-potassium alloy one. Prospects of lithium coolant use in developing current powerful SNPP are shown. Reliable operation of liquid metal part (with sodium-potassium coolant) of SNPP of low power and limited life at satellites launching in the USSR in 1970-80s is pointed out

  11. A Compact Nuclear Fusion Reactor for Space Flights

    A small-scale nuclear fusion reactor is suggested based on the concepts of plasma confinement (with a high pressure gas) which have been patented by the author. The reactor considered can be used as a power setup in space flights. Among the advantages of this reactor is the use of a D3He fuel mixture which at burning gives main reactor products -- charged particles. The energy balance considerably improves, as synchrotron radiation turn out 'captured' in the plasma volume, and dangerous, in the case of classical magnetic confinement, instabilities in the direct current magnetic field configuration proposed do not exist. As a result, the reactor sizes are quite suitable (of the order of several meters). A possibility of making reactive thrust due to employment of ejection of multiply charged ions formed at injection of pellets from some adequate substance into the hot plasma center is considered

  12. Space nuclear power in views: 50 years ago and prevision for 50 years

    Full text: The second half of the XXth century became the age of the origin and formation of space nuclear power. During that time the potentialities and advantages of its application in large, medium and small nuclear rocket propulsions (NRP) were being earnestly demonstrated. The prototypes of different level NRP reactors were being tested in the USA and in the USSR during 1970-1980. Since 1956 the practical works on studying the opportunities of use the nuclear power installations (NPI) with direct methods of converting thermal power into electricity at the space vehicles have been launched. In addition to radio-isotopic space generators of current, reactor thermoelectric installations SNAP-10A of 0,5 kW, 'Bouk' of 3 kW and thermo-emission installation 'TOPAZ' of ∼6 kW were proposed, designed and constructed. 32 'Bouk' installations were operating in space during 1970-1988. Two 'TOPAZ' installations successfully passed flight space testing in 1987-1988. An important contribution to design and construction of 'Bouk' and 'TOPAZ' installations was made by V. Ya. Poupko. Simultaneously with the designs which reached their technical realization, the feasibility studies of the whole number of installations with different class reactors were carried out in the USSR (Russia) and USA. Brief descriptions of some of them are cited in the present Report. They were the modernized variants of thermo-emission and thermoelectric installations ('TOPAZ-2', SP-100) as well as the variants of combinations of the NPIs with multi-mode functioning, installations with power convert systems removed from the core, bimodal installations using NRP and NPI solutions, installations based on the lithium-niobium technology and installations with machine methods of conversion. However, in the end of the XXth - in the beginning of the XXIst centuries, depending on the economical expedience of the space NPIs, the higher requirements were presented to power (from several kW units to several

  13. Space nuclear power requirements for ozone layer modification

    This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O3) in the Earth's atmosphere is estimated to be about 4.7 x 1037 molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 x 1031 molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time ∼ 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O2 (leading to production of atomic oxygen, which can combine with O2 to form O3) than in ozone (leading to photodissociation of O3). Potential radiation sources include H2 lasers and direct nuclear pumping of ultraviolet fluorescers. 5 refs

  14. IEEE Nuclear and Space Radiation Effects Conference: Notes on the Early Conferences

    Pellish, Jonathan A.; Galloway, Kenneth F.

    2013-01-01

    This paper gathers the remembrances of several key contributors who participated in the earliest Institute of Electrical and Electronics Engineers (IEEE) Nuclear and Space Radiation Effects Conferences (NSREC).

  15. Technology status of tantalum alloys for space nuclear power applications

    Tantalum alloys have a variety of properties which make them attractive candidates for application in nuclear power systems required to operate in space at elevated temperatures (1200 to 16000K) for extended time periods. Most of the technology development on this class of alloys which is pertinent to space system application occurred during the 1960 to 1972 time period under NASA sponsorship. The most extensive data bases resulting from this earlier work were obtained on the alloys T-111 (Ta-8W-2Hf) and ASTAR 811C (Ta-8W-1Re-0.7Hf-0.025C). Emphasis in this paper is directed at the following technical factors: producibility, creep strength, weldability and compatibility. These factors are considered to be the most important elements in the selection of alloys for this application. Review of the available information indicates that alloys of this type are appropriate for application in many systems, particularly those utilizing alkali metals as the working fluid. 43 refs

  16. Silicon Carbide Based Power Mangement and Distribution for Space Nuclear Power Systems Project

    National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard, 100's kWe power management and distribution (PMAD) system for space nuclear...

  17. Progress in space nuclear reactor power systems technology development. The SP-100 program

    Activities related to the development of high-temperature compact nuclear reactors for space applications had reached a comparatively high level in the U.S. during the mid-1950s and 1960s, although only one U.S. nuclear reactor-powered spacecraft was actually launched. After 1973, very little effort was devoted to space nuclear reactor and propulsion systems. In February 1983, significant activities toward the development of the technology for space nuclear reactor power systems were resumed with the SP-100 Program. Specific SP-100 Program objectives are partly related to the determination of the potential performance limits for space nuclear power systems in 100-kWe and 1- to 100-MW electrical classes. Attention is given to potential missions and applications, regimes of possible space power applicability, safety considerations, conceptual system designs, the establishment of technical feasibility, nuclear technology, materials technology, and prospects for the future. 5 references

  18. The flight safety review/approval process for U.S. nuclear-powered space missions

    Since 1961, the US has launched > 20 spacecraft using nuclear power sources. One of these space missions involved a nuclear reactor; the remainder were powered by radioisotope thermoelectric generators (RTGs). Space nuclear power/propulsion systems are receiving greater attention in the US and abroad. These developments suggest that nuclear systems may play an expanding role in future space endeavors. Although space nuclear power/propulsion offers distinct advantages, it also poses significant safety challenges. Stringent design and operational flight safety measures are required to protect the public an the environment under normal and accident conditions. Moreover, formal safety reviews are mandatory to obtain flight approval. This paper describes the flight safety review and launch approval process used in the US for nuclear-powered space missions

  19. Summary of space nuclear reactor power systems, 1983--1992

    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

  20. Application of wavelet analysis to the nuclear phase space study

    The objective of this thesis is to present a methodology, based on the projection methods used in statistical physics and on the wavelet approach, which allows to obtain various classes of information. A coherent modelling was elaborated as the tools used for generating and solving the evolution equations, expressed in terms of pertinent variables, are based on common concepts. The property of scale separation of the wavelet analysis allows an approximation hierarchy based on the geometrical structure of phase space to be defined. This information structuration offers the opportunity of solving the evolution equations with various degrees of precision by controlling the information loss and avoiding the sampling methods of Monte Carlo type. The application of this methodology to the case of heavy ion collisions needs an entirely numerical treatment of the density matrix evolution equation. This implies a very precise level of description in order to take into account the important dissipation effects occurring in intermediate energy nuclear dynamics. A proper solution less expensive was adopted by using the wavelets analytically expressed, this entailing also the testing of model validity by comparing its results with the analytical solutions. This model takes into account the structure of the system wave functions, thus conserving the microscopical information. The present methodology can be applied also at other energy domains providing the nuclear systems are subject to transient non steady-state regimes. The wavelet analysis was used extensively in the field of signal processing particularly to extract from background a physical signal and also in the field of turbulence phenomena

  1. Summary of space nuclear reactor power systems, 1983--1992

    Buden, D.

    1993-08-11

    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.

  2. Space nuclear reactor system diagnosis: Knowledge-based approach

    SP-100 space nuclear reactor system development is a joint effort by the Department of Energy, the Department of Defense and the National Aeronautics and Space Administration. The system is designed to operate in isolation for many years, and is possibly subject to little or no remote maintenance. This dissertation proposes a knowledge based diagnostic system which, in principle, can diagnose the faults which can either cause reactor shutdown or lead to another serious problem. This framework in general can be applied to the fully specified system if detailed design information becomes available. The set of faults considered herein is identified based on heuristic knowledge about the system operation. The suitable approach to diagnostic problem solving is proposed after investigating the most prevalent methodologies in Artificial Intelligence as well as the causal analysis of the system. Deep causal knowledge modeling based on digraph, fault-tree or logic flowgraph methodology would present a need for some knowledge representation to handle the time dependent system behavior. A proposed qualitative temporal knowledge modeling methodology, using rules with specified time delay among the process variables, has been proposed and is used to develop the diagnostic sufficient rule set. The rule set has been modified by using a time zone approach to have a robust system design. The sufficient rule set is transformed to a sufficient and necessary one by searching the whole knowledge base. Qualitative data analysis is proposed in analyzing the measured data if in a real time situation. An expert system shell - Intelligence Compiler is used to develop the prototype system. Frames are used for the process variables. Forward chaining rules are used in monitoring and backward chaining rules are used in diagnosis

  3. Analysis of space systems study for the space disposal of nuclear waste study report. Volume 2: Technical report

    1981-01-01

    Reasonable space systems concepts were systematically identified and defined and a total system was evaluated for the space disposal of nuclear wastes. Areas studied include space destinations, space transportation options, launch site options payload protection approaches, and payload rescue techniques. Systems level cost and performance trades defined four alternative space systems which deliver payloads to the selected 0.85 AU heliocentric orbit destination at least as economically as the reference system without requiring removal of the protective radiation shield container. No concepts significantly less costly than the reference concept were identified.

  4. Gas Foil Bearings for Space Propulsion Nuclear Electric Power Generation

    Howard, Samuel A.; DellaCorte, Christopher

    2006-01-01

    The choice of power conversion technology is critical in directing the design of a space vehicle for the future NASA mission to Mars. One candidate design consists of a foil bearing supported turbo alternator driven by a helium-xenon gas mixture heated by a nuclear reactor. The system is a closed-loop, meaning there is a constant volume of process fluid that is sealed from the environment. Therefore, foil bearings are proposed due to their ability to use the process gas as a lubricant. As such, the rotor dynamics of a foil bearing supported rotor is an important factor in the eventual design. The current work describes a rotor dynamic analysis to assess the viability of such a system. A brief technology background, assumptions, analyses, and conclusions are discussed in this report. The results indicate that a foil bearing supported turbo alternator is possible, although more work will be needed to gain knowledge about foil bearing behavior in helium-xenon gas.

  5. Stirling System Modeling for Space Nuclear Power Systems

    Lewandowski, Edward J.; Johnson, Paul K.

    2008-01-01

    A dynamic model of a high-power Stirling convertor has been developed for space nuclear power systems modeling. The model is based on the Component Test Power Convertor (CTPC), a 12.5-kWe free-piston Stirling convertor. The model includes the fluid heat source, the Stirling convertor, output power, and heat rejection. The Stirling convertor model includes the Stirling cycle thermodynamics, heat flow, mechanical mass-spring damper systems, and the linear alternator. The model was validated against test data. Both nonlinear and linear versions of the model were developed. The linear version algebraically couples two separate linear dynamic models; one model of the Stirling cycle and one model of the thermal system, through the pressure factors. Future possible uses of the Stirling system dynamic model are discussed. A pair of commercially available 1-kWe Stirling convertors is being purchased by NASA Glenn Research Center. The specifications of those convertors may eventually be incorporated into the dynamic model and analysis compared to the convertor test data. Subsequent potential testing could include integrating the convertors into a pumped liquid metal hot-end interface. This test would provide more data for comparison to the dynamic model analysis.

  6. Civilian and military applications of space nuclear power: a congressional perspective

    I would like to talk about how space nuclear power fits into space programs in general. You are aware that NASA identified a civilian use that would require nuclear power on the order of 100 kilowatts - that is planetary exploration - before the military indicated their interest. Actually there are many possible civilian and military uses for space nuclear power. I would like to briefly review them because it provides insight into the future direction of the US space program. I would also like to discuss the baseline directed energy weapons program that appears to be emerging

  7. A comparative study of nuclear technology and direct energy conversion methods for space power systems

    Reason, Joseph P., Jr.

    1997-01-01

    Approved for public release; distribution in unlimited. The objectives of this thesis are to investigate the theory of direct energy conversion, research the development of space nuclear power systems, evaluate the status of current systems, and draw conclusions about the feasibility and merit of using nuclear power for future space missions. Development of the earliest systems began in 1955 with the Systems for Nuclear Auxiliary Power (SNAP) Program and Project Rover. A detailed review of...

  8. Radionuclide inventories for short run-time space nuclear reactor systems

    Space Nuclear Reactor Systems, especially those used for propulsion, often have expected operation run times much shorter than those for land-based nuclear power plants. This produces substantially different radionuclide inventories to be considered in the safety analyses of space nuclear systems. This presentation describes an analysis utilizing ORIGEN2 and DKPOWER to provide comparisons among representative land-based and space systems. These comparisons enable early, conceptual considerations of safety issues and features in the preliminary design phases of operational systems, test facilities, and operations by identifying differences between the requirements for space systems and the established practice for land-based power systems. Early indications are that separation distance is much more effective as a safety measure for space nuclear systems than for power reactors because greater decay of the radionuclide activity occurs during the time to transport the inventory a given distance. In addition, the inventories of long-lived actinides are very low for space reactor systems

  9. Nuclear Propulsion for Space, Understanding the Atom Series.

    Corliss, William R.; Schwenk, Francis C.

    The operation of nuclear rockets with respect both to rocket theory and to various fuels is described. The development of nuclear reactors for use in nuclear rocket systems is provided, with the Kiwi and NERVA programs highlighted. The theory of fuel element and reactor construction and operation is explained with particular reference to rocket…

  10. Space Nuclear Power Public and Stakeholder Risk Communication

    Dawson, Sandra M.; Sklar, Maria

    2005-01-01

    The 1986 Challenger accident coupled with the Chernobyl nuclear reactor accident increased public concern about the safety of spacecraft using nuclear technology. While three nuclear powered spacecraft had been launched before 1986 with little public interest, future nuclear powered missions would see significantly more public concern and require NASA to increase its efforts to communicate mission risks to the public. In 1987 a separate risk communication area within the Launch Approval Planning Group of the Jet Propulsion Laboratory was created to address public concern about the health, environmental, and safety risks of NASA missions. The lessons learned from the risk communication strategies developed for the nuclear powered Galileo, Ulysses, and Cassini missions are reviewed in this paper and recommendations are given as to how these lessons can be applied to future NASA missions that may use nuclear power systems and other potentially controversial NASA missions.

  11. Absolute nuclear material assay using count distribution (LAMBDA) space

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  12. Absolute nuclear material assay using count distribution (LAMBDA) space

    Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.

    2015-12-01

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  13. Review of the Tri-Agency Space Nuclear Reactor Power System Technology Program

    The Space Nuclear Reactor Power System Technology Program (SP-100) was created in February 1983 by Memorandum of Agreement among NASA, DARPA and DOE. The tasks of the SP-100 organization in its first year have included detailed program, objective, and role definition; civil and military mission analysis; space nuclear power system functional requirement definition; conclusion of initial space nuclear power system concepted definition studies; selection of primary concepts for technology feasibility validation; defining and initiating specific technology programs and objectives to support the system concepts; and obtaining initial experimental and analytic results

  14. Thermal Simulator Development: Non-Nuclear Testing of Space Fission Systems

    Bragg-Sitton, Shannon M.; Dickens, Ricky E.

    2006-01-01

    Non-nuclear testing can be a valuable tool in the development of a space nuclear power system. At the NASA MSFC Early Flight Fission Test Facility (EFF-TF), highly designed electric heaters are used to simulate the heat from nuclear fuel to test space fission power and propulsion systems. To allow early utilization, nuclear system designs must be relatively simple, easy to fabricate, and easy to test using non-nuclear heaters to closely mimic heat from fission. In this test strategy, highly designed electric heaters are used to simulate the heat from nuclear fuel, allowing one to develop a significant understanding of individual components and integrated system operation without the cost, time and safety concerns associated with nuclear testing.

  15. Lightweight Radiator Fins for Space Nuclear Power Project

    National Aeronautics and Space Administration — This SBIR Phase 1 project shall investigate concept radiator fins that incorporate novel carbon materials for improved performance of segmented high temperature...

  16. Ground test facility for nuclear testing of space reactor subsystems

    Two major reactor facilities at the INEL have been identified as easily adaptable for supporting the nuclear testing of the SP-100 reactor subsystem. They are the Engineering Test Reactor (ETR) and the Loss of Fluid Test Reactor (LOFT). In addition, there are machine shops, analytical laboratories, hot cells, and the supporting services (fire protection, safety, security, medical, waste management, etc.) necessary to conducting a nuclear test program. This paper presents the conceptual approach for modifying these reactor facilities for the ground engineering test facility for the SP-100 nuclear subsystem. 4 figs

  17. Analysis of space systems for the space disposal of nuclear waste follow-on study. Volume 2: Technical report

    1982-01-01

    The space option for disposal of certain high-level nuclear wastes in space as a complement to mined geological repositories is studied. A brief overview of the study background, scope, objective, guidelines and assumptions, and contents is presented. The determination of the effects of variations in the waste mix on the space systems concept to allow determination of the space systems effect on total system risk benefits when used as a complement to the DOE reference mined geological repository is studied. The waste payload system, launch site, launch system, and orbit transfer system are all addressed. Rescue mission requirements are studied. The characteristics of waste forms suitable for space disposal are identified. Trajectories and performance requirements are discussed.

  18. Nuclear Thermal Propulsion (NTP) Development Activities at the NASA Marshall Space Flight Center - 2006 Accomplishments

    Ballard, Richard O.

    2007-01-01

    In 2005-06, the Prometheus program funded a number of tasks at the NASA-Marshall Space Flight Center (MSFC) to support development of a Nuclear Thermal Propulsion (NTP) system for future manned exploration missions. These tasks include the following: 1. NTP Design Develop Test & Evaluate (DDT&E) Planning 2. NTP Mission & Systems Analysis / Stage Concepts & Engine Requirements 3. NTP Engine System Trade Space Analysis and Studies 4. NTP Engine Ground Test Facility Assessment 5. Non-Nuclear Environmental Simulator (NTREES) 6. Non-Nuclear Materials Fabrication & Evaluation 7. Multi-Physics TCA Modeling. This presentation is a overview of these tasks and their accomplishments

  19. Space nuclear power system concepts and the test facility needs/programmatic requirements

    This paper gives an overview of the planning needs for the SP-100 and Megawatt Class Nuclear Space Power Systems programs. Factors of concern include: establishment of mission performance test goals; determination of current Federal Order requirements; compliance with applicable institutional and regulatory requirements, especially those related to site environmental qualification; analysis of lessons learned from the commercial nuclear power, NERVA and SNAP programs; determination of needed technical program support services; analysis of regulatory requirements for similar nuclear programs; establishment of test program safeguards and security; analysis of public health and safety; determination of site program readiness; and determination of public acceptance of the space program and the proposed test site

  20. Assessment of Space Nuclear Thermal Propulsion Facility and Capability Needs

    The development of a Nuclear Thermal Propulsion (NTP) system rests heavily upon being able to fabricate and demonstrate the performance of a high temperature nuclear fuel as well as demonstrating an integrated system prior to launch. A number of studies have been performed in the past which identified the facilities needed and the capabilities available to meet the needs and requirements identified at that time. Since that time, many facilities and capabilities within the Department of Energy have been removed or decommissioned. This paper provides a brief overview of the anticipated facility needs and identifies some promising concepts to be considered which could support the development of a nuclear thermal propulsion system. Detailed trade studies will need to be performed to support the decision making process.

  1. Space exploration initiative candidate nuclear propulsion test facilities

    Baldwin, Darrell; Clark, John S.

    1993-01-01

    One-page descriptions for approximately 200 existing government, university, and industry facilities which may be available in the future to support SEI nuclear propulsion technology development and test program requirements are provided. To facilitate use of the information, the candidate facilities are listed both by location (Index L) and by Facility Type (Index FT). The included one-page descriptions provide a brief narrative description of facility capability, suggest potential uses for each facility, and designate a point of contact for additional information that may be needed in the future. The Nuclear Propulsion Office at NASA Lewis presently plans to maintain, expand, and update this information periodically for use by NASA, DOE, and DOD personnel involved in planning various phases of the SEI Nuclear Propulsion Project.

  2. Assessment of Space Nuclear Thermal Propulsion Facility and Capability Needs

    James Werner

    2014-07-01

    The development of a Nuclear Thermal Propulsion (NTP) system rests heavily upon being able to fabricate and demonstrate the performance of a high temperature nuclear fuel as well as demonstrating an integrated system prior to launch. A number of studies have been performed in the past which identified the facilities needed and the capabilities available to meet the needs and requirements identified at that time. Since that time, many facilities and capabilities within the Department of Energy have been removed or decommissioned. This paper provides a brief overview of the anticipated facility needs and identifies some promising concepts to be considered which could support the development of a nuclear thermal propulsion system. Detailed trade studies will need to be performed to support the decision making process.

  3. Use of nuclear data for space and aeronautic designs

    Until recently, the effects of radiation environment on on-board electronics on launchers and aircraft had not been seriously taken into account. The situation has changed. And one of the most significant effects observed on on-board electronics is what we call Single Event Upset (SEU). This talk explains how the combination of electrical sensitivity of components and nuclear physics is important in the calculation of SEU rates, and emphasizes the aspects of nuclear physics useful to give the probability for a dangerous event to occur. Some circumvention methods will be rapidly identified. (authors)

  4. Simulation and primary circuit control of the SP-100 space nuclear power reactor

    Space nuclear power reactors with thermoelectric conversion are one of the main sources for space application that can provide enough electric power. In this paper we discuss the working conditions, basic structure and operational characteristics of an EMTE pump needed to flow control of a metal liquid nuclear space reactor primary circuit. The BEMTE-1 program is used to study this system during normal operation to simulate the SP-100 american reactor primary cooling circuit and to obtain the actuation point of the system. (author)

  5. Space Nuclear Safety Program. Progress report, April 1984

    George, T.G. (comp.)

    1985-10-01

    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 and recovery, and safety technology program (biaxial testing, iridium chemistry).

  6. Space nuclear-safety program. Progress report, October 1982

    Bronisz, S.E. (comp.)

    1983-03-01

    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.

  7. Space Nuclear Safety Program. Progress report, August 1984

    George, T.G. (comp.)

    1985-11-01

    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 are ongoing; the results and conclusions described may change as the work progresses. 41 figs.

  8. Space Nuclear Safety Program. Progress report, June 1984

    George, T.G. (comp.)

    1985-11-01

    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 are ongoing; the results and conclusions described may change as the work continues. 36 figs.

  9. Space Nuclear Safety Program. Progress report, March 1984

    Zocher, R.W.; George, T.G. (comps.)

    1985-08-01

    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 Laboratory. They are divided into: general-purpose heat source, lightweight radioisotope heater unit, and safety technology program. 43 figs., 2 tabs.

  10. Space Nuclear Safety Program. Progress report, July 1984

    George, T.G. (comp.)

    1985-11-01

    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. 10 figs.

  11. Space nuclear safety program. Progress report, October 1983

    Bronisz, S.E. (comp.)

    1984-03-01

    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.

  12. Space nuclear-safety program, November 1982. Progress report

    Bronisz, S.E. (comp.)

    1983-05-01

    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.

  13. Space nuclear safety program. Progress report, January 1984

    Bronisz, S.E. (comp.)

    1984-07-01

    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.

  14. Assessment of ceramic composites for MMW space nuclear power systems

    Proposed multimegawatt nuclear power systems which operate at high temperatures, high levels of stress, and in hostile environments, including corrosive working fluids, have created interest in the use of ceramic composites as structural materials. This report assesses the applicability of several ceramic composites in both Brayton and Rankine cycle power systems. This assessment considers an equilibrium thermodynamic analysis and also a nonequilibrium assessment. (FI)

  15. Space nuclear safety program. Progress report, July 1983

    This technical monthly report covers studies related to the use of 238PuO2 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

  16. Review of the design status of the SP-100 Space Nuclear Power System

    The Heat Pipe Space Nuclear Reactor (HPSNR) System is one of the advanced designs for space nuclear power applications presently being considered. However, a number of design features will continue to require substantial technology and development before considering the system for deployment. This paper reviews the design status of the HPSNR system, as of October 1982, discusses the limitations of the current design and emphasizes those technical areas requiring additional research needed to support continual system development. The topics and design limitations discussed are common to most space nuclear power systems that are currently being developed under the SP-100 program to produce 100 kWe of continuous power in a space environment

  17. Thermal radiation in gas core nuclear reactors for space propulsion

    A diffusive model of the radial transport of thermal radiation out of a cylindrical core of fissioning plasma is presented. The diffusion approximation is appropriate because the opacity of uranium is very high at the temperatures of interest (greater than 3000 K). We make one additional simplification of assuming constant opacity throughout the fuel. This allows the complete set of solutions to be expressed as a single function. This function is approximated analytically to facilitate parametric studies of the performance of a test module of the nuclear light bulb gas-core nuclear-rocket-engine concept, in the Annular Core Research Reactor at Sandia National Laboratories. Our findings indicate that radiation temperatures in range of 4000-6000 K are attainable, which is sufficient to test the high specific impulse potential (approximately 2000 s) of this concept. 15 refs

  18. A fission fragment reactor concept for nuclear space propulsion

    Suo-Anttila, A. J.; Parma, E. J.; Wright, S. A.; Vernon, M. E.; Pickard, P. S.

    1991-10-01

    Sandia National Laboratory (SNL) has proposed a new nuclear thermal propulsion concept that uses fission fragments to directly heat the propellant up to 1000 K or higher above the material temperatures. The concept offers significant advantages over traditional solid core nuclear rocket concepts because of higher propellant exit temperatures while at the same time providing for more reliable operation due to lower structure temperatures and lower power densities. The concept can be operated in either steady state or pulsed modes. The engine consists of tubular modules, each with its own pressure boundary and rocket nozzle. The steady state mode requires a large engine with a reflector for criticality, provides high thrust and high ISP. The pulse mode utilizes a driver reactor for criticality and can be considerably smaller with lower but scaleable thrust. The pulse mode does require an external heat radiator for reactor cooling, which limits its duty cycle.

  19. Advanced Space Nuclear Reactors from Fiction to Reality

    Popa-Simil, L.

    The advanced nuclear power sources are used in a large variety of science fiction movies and novels, but their practical development is, still, in its early conceptual stages, some of the ideas being confirmed by collateral experiments. The novel reactor concept uses the direct conversion of nuclear energy into electricity, has electronic control of reactivity, being surrounded by a transmutation blanket and very thin shielding being small and light that at its very limit may be suitable to power an autonomously flying car. It also provides an improved fuel cycle producing minimal negative impact to environment. The key elements started to lose the fiction attributes, becoming viable actual concepts and goals for the developments to come, and on the possibility to achieve these objectives started to become more real because the theory shows that using the novel nano-technologies this novel reactor might be achievable in less than a century.

  20. Thermal radiation in gas core nuclear reactors for space propulsion

    Slutz, S.A.; Gauntt, R.O.; Harms, G.A.; Latham, T.; Roman, W.; Rodgers, R.J. (Sandia National Lab, Albuquerque, NM (United States))

    1994-05-01

    A diffusive model of the radial transport of thermal radiation out of a cylindrical core of fissioning plasma is presented. The diffusion approximation is appropriate because the opacity of uranium is very high at the temperatures of interest (greater than 3000 K). We make one additional simplification of assuming constant opacity throughout the fuel. This allows the complete set of solutions to be expressed as a single function. This function is approximated analytically to facilitate parametric studies of the performance of a test module of the nuclear light bulb gas-core nuclear-rocket-engine concept, in the Annular Core Research Reactor at Sandia National Laboratories. Our findings indicate that radiation temperatures in range of 4000-6000 K are attainable, which is sufficient to test the high specific impulse potential (approximately 2000 s) of this concept. 15 refs.

  1. Space Nuclear Safety Program. Progress report, November 1983

    Bronisz, S.E. (comp.)

    1984-06-01

    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. Topics discussed include: safety-verification impact tests; explosion test; fragment test; leaking fueled clads; effects of fresh water and seawater or PuO/sub 2/ pellets; and impact tests of 5 watt radioisotope thermoelectric generator.

  2. Instrument for registration of nuclear fluxes in near outer space

    An instrument is described in which the stacks of photoemulsion of cellulose nitrate that register nuclear tracks are exposed on board a low-orbit satellite at certain points on its flight trajectory. The particle flux is shut off by means of a mechanical shutter, which is controlled by a gas-discharge counter of cosmic rays, whose intensity is a function of the geographical latitude

  3. Calculation of nuclear electromagnetic pulse propagation into space

    The wave of NEMP propagation through ionosphere into space are calculated by means of the radial-trace method. With the expression and delays of the ionosphere, NEMP wave turned into a vibrating wave. Numerical simulations show that NEMP can be measured at the orbit of satellite. (authors)

  4. Nuclear reactor closed Brayton cycle space power conversion systems

    This paper presents the past history, present status and future prospects for closed Brayton cycle power conversion systems to be used in space when requirements have been established. Since there is a classic lack of coordination between advanced technology and its perceived need that can be strongly affected by associated factors, recommendations will be made to assist in the current situation. 4 refs

  5. Feasibility of Low Enriched Uranium Fuel for Space Nuclear Propulsion

    The purpose of this initial study is to create a baseline with which to perform further analysis and to build a solid understanding of the neutronic characteristics of a solid core for the nuclear thermal rocket. Once consistency with work done at Idaho National Laboratory (INL) is established, this paper will provide a study of other fuel types, such as low and medium-enriched uranium fuels. This paper will examine how the implementation of each fuel type affects the multiplication factor of the reactor, and will then explore different possibilities for alterations needed to accommodate their successful usage. The reactor core analysis was done using the MCNP5 code. While this study has not shown that the SNRE can be easily retrofitted for low-enriched U fuel, it has made a detailed study of the SNRE, and identified the difficulties of the implementation of low-enriched fuels in small nuclear rockets. These difficulties are the need for additional moderation and fuel mass in order to achieve a critical mass. Neither of these is insurmountable. Future work includes finding the best method by which to increase the internal moderation of the reactor balanced with appropriate sizing to prevent neutron leakage. Both of these are currently being studied. This paper will present a study of the Small Nuclear Rocket Engine (SNRE) and the feasibility of using low enriched Uranium (LEU) instead of the traditional high enriched Uranium (HEU) fuels

  6. Thermoelectric converter modeling in nuclear space power conversion and regulation

    Thermoelectric converters are being used on low power planetary spacecraft. The same type of conversion was considered for Ground Engineering System development of nuclear power generation under the SP-100 program for high power earth orbiting spacecraft. Here, the baseline design is aimed at generating power using a nuclear reactor to produce heat, a thermoelectric converter to produce electricity, a power regulator to match the output to changing payload demands, and a thermal radiator to dissipate waste heat. The converter performance has to be evaluated considering its characteristics. The characteristics and constraints imposed by the nuclear reactor, the payloads and regulator, and the waste heat radiator should be conformed to. Presented here are a thermodynamic reversible engine model for the thermoelectric converter, and its application to evaluate the converter and system performance under steady-state and transient thermal conditions due to load changes. The type of output voltage regulator, either a series or shunt, has an impact on the converter performance. This impact is evaluated and advantages and disadvantages of both are indicated. The converter performance is evaluated along its voltage-current characteristics. Influence of the conversion efficiency is assessed on thermal distribution and electrical output

  7. Feasibility of Low Enriched Uranium Fuel for Space Nuclear Propulsion

    Venneri, Paolo; Kim, Yonghee [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The purpose of this initial study is to create a baseline with which to perform further analysis and to build a solid understanding of the neutronic characteristics of a solid core for the nuclear thermal rocket. Once consistency with work done at Idaho National Laboratory (INL) is established, this paper will provide a study of other fuel types, such as low and medium-enriched uranium fuels. This paper will examine how the implementation of each fuel type affects the multiplication factor of the reactor, and will then explore different possibilities for alterations needed to accommodate their successful usage. The reactor core analysis was done using the MCNP5 code. While this study has not shown that the SNRE can be easily retrofitted for low-enriched U fuel, it has made a detailed study of the SNRE, and identified the difficulties of the implementation of low-enriched fuels in small nuclear rockets. These difficulties are the need for additional moderation and fuel mass in order to achieve a critical mass. Neither of these is insurmountable. Future work includes finding the best method by which to increase the internal moderation of the reactor balanced with appropriate sizing to prevent neutron leakage. Both of these are currently being studied. This paper will present a study of the Small Nuclear Rocket Engine (SNRE) and the feasibility of using low enriched Uranium (LEU) instead of the traditional high enriched Uranium (HEU) fuels.

  8. Nuclear disassembly time scales using space time correlations

    The lifetime, τ, with respect to multifragmentation of highly excited nuclei is deduced from the analysis of strongly damped Pb+Au collisions at 29 MeV/u. The method is based on the study of space-time correlations induced by 'proximity' effects between fragments emitted by the two primary products of the reaction and gives the time between the re-separation of the two primary products and the subsequent multifragment decay of one partner. (author)

  9. Ventilation of a nuclear space: modelling, experimental validation and consequences

    The present problems raised by ventilation are stated, and a review is made of the models of contamination dispersion and calculation of the contaminant concentrations and their validity as to the data collected during radiological events. A model more suitable to the conditions prevailing in installations has been derived from these models in order to describe the evolution of contaminant concentrations in a ventilated space

  10. Nuclear power in space. Use of reactors and radioactive substances as power sources in satellites and space probes

    Today solar panels are the most common technique to supply power to satellites. Solar panels will work as long as the power demand of the satellite is limited and the satellite can be equipped with enough panels, and kept in an orbit that allows enough sunlight to hit the panels. There are various types of space missions that do not fulfil these criteria. With nuclear power these types of missions can be powered regardless of the sunlight and as early as 1961 the first satellite with a nuclear power source was placed in orbit. Out of seventy known space missions that has made use of nuclear power, ten have had some kind of failure. In no case has the failure been associated with the nuclear technology used. This report discusses to what degree satellites with nuclear power are a source for potential radioactive contamination of Swedish territory. It is not a discussion for or against nuclear power in space. Neither is it an assessment of consequences if radioactive material from a satellite would reach the earth's surface. Historically two different kinds of Nuclear Power Sources (NPS) have been used to generate electric power in space. The first is the reactor where the energy is derived from nuclear fission of 235U and the second is the Radioisotope Thermoelectric Generator (RTG) where electricity is generated from the heat of naturally decaying radionuclides. NPS has historically only been used in space by United States and the Soviet Union (and in one failing operation Russia). Nuclear Power Sources have been used in three types of space objects: satellites, space probes and moon/Mars vehicles. USA has launched one experimental reactor into orbit, all other use of NPS by the USA has been RTG:s. The Soviet Union, in contrast, only launched a few RTG:s but nearly forty reactors. The Soviet use of NPS is less transparent than the use in USA and some data published on Soviet systems are more or less well substantiated assessments. It is likely that also future

  11. Status of the CNES-CEA joint program on space nuclear Brayton systems

    A Cooperative program between the French Centre National d'Etudes Spatiales (CNES) and the Commissariat a l'Engergie Atomique (CEA) was initiated in 1983, to investigate the possible development of 20 to 200 kWe space nuclear power systems to be launched by the next version of the European launcher, Ariane V. After completion in 1986 of preliminary conceptual studies of a reference 200 kWe turboelectric power system, an additional 3 year study phase was decided, with the double objective of assessing the potential advantage of nuclear power systems versus solar photovoltaic or dynamic systems in the 20 kWe power range, and comparing various reactor candidate technologies and systems options for 20 kWe space nuclear power systems, likely to meet the projected energy needs of future European space missions. The results of this study are discussed by the authors

  12. Space nuclear-power reactor design based on combined neutronic and thermal-fluid analyses

    The design and performance analysis of a space nuclear-power system requires sophisticated analytical capabilities such as those developed during the nuclear rocket propulsion (Rover) program. In particular, optimizing the size of a space nuclear reactor for a given power level requires satisfying the conflicting requirements of nuclear criticality and heat removal. The optimization involves the determination of the coolant void (volume) fraction for which the reactor diameter is a minimum and temperature and structural limits are satisfied. A minimum exists because the critical diameter increases with increasing void fraction, whereas the reactor diameter needed to remove a specified power decreases with void fraction. The purpose of this presentation is to describe and demonstrate our analytical capability for the determination of minimum reactor size. The analysis is based on combining neutronic criticality calculations with OPTION-code thermal-fluid calculations

  13. Possibilities of Kazakhstan experimental base for space nuclear reactors elements testing

    To the mid of 70-th in Kazakhstan the surface developing base for space nuclear reactors elements testing was created. The base consists of three test complexes. Two of them - the complexes of test reactors 'Baikal-1' and IGR - are situating on the Semipalatinsk test site, and the third one - complex of WWR-K research reactor - is situating in Alatau village nearby to Almaty city. On 'Baikal-1' and IGR complexes the testings for fuel elements, fuel assemblies, modules and prototypes of nuclear rocket engine reactor and nuclear energetic engine units with turbine-engine energy transmission on the base solid-phase reactor were carrying out. On the WWR-K reactor complex the testing of power generating channels of thermal-emission transmission reactors were conducted. In the paper the assessment of up-to-date experimental base status and it possibilities for further using in space nuclear energy field are given

  14. Study of nuclear pairing with Configuration-Space Monte-Carlo approach

    Lingle, Mark; Volya, Alexander

    2015-01-01

    Pairing correlations in nuclei play a decisive role in determining nuclear drip-lines, binding energies, and many collective properties. In this work a new Configuration-Space Monte-Carlo (CSMC) method for treating nuclear pairing correlations is developed, implemented, and demonstrated. In CSMC the Hamiltonian matrix is stochastically generated in Krylov subspace, resulting in the Monte-Carlo version of Lanczos-like diagonalization. The advantages of this approach over other techniques are d...

  15. General-purpose heat source project and space nuclear safety and fuels program. Progress report

    This formal monthly report covers the studies related to the use of 238PuO2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed hear are of a continuing nature. Results and conclusions described may change as the work continues

  16. Direct Estimation of Power Distribution in Reactors for Nuclear Thermal Space Propulsion

    Aldemir, Tunc; Miller, Don W.; Burghelea, Andrei

    2004-02-01

    A recently proposed constant temperature power sensor (CTPS) has the capability to directly measure the local power deposition rate in nuclear reactor cores proposed for space thermal propulsion. Such a capability reduces the uncertainties in the estimated power peaking factors and hence increases the reliability of the nuclear engine. The CTPS operation is sensitive to the changes in the local thermal conditions. A procedure is described for the automatic on-line calibration of the sensor through estimation of changes in thermal .conditions.

  17. Human Factors and Information Operation for a Nuclear Power Space Vehicle

    This paper describes human-interactive systems needed for a crew nuclear-enabled space mission. A synthesis of aircraft engine and nuclear power plant displays, biofeedback of sensory input, virtual control, brain mapping for control process and manipulation, and so forth are becoming viable solutions. These aspects must maintain the crew's situation awareness and performance, which entails a delicate function allocation between crew and automation. (authors)

  18. Status of the CNES-CEA joint program on space nuclear Brayton systems

    A cooperative program between the French Centre National d'Etudes Spatiales (CNES) and the Commissariat a l'Energie Atomique (CEA) was initiated in 1983, to investigate the possible development of 20 to 200 kWe space nuclear power systems to be launched by the next version of the European launcher, Ariane V. After completion in 1986 of preliminary conceptual studies of a reference 200 kWe turbo-electric power system, an additional 3 year study phase was decided, with the double objective of assessing the potential advantage of nuclear power systems versus solar photovoltaic or dynamic systems in the 20 kWe power range, and comparing various reactor candidate technologies and system options for 20 kWe space nuclear power systems, likely to meet the projected energy needs of future European space missions. A comprehensive program including conceptual design studies, operating transient analyses and technology base assessment, is currently applied to a few reference concepts of 20 kWe nuclear Brayton and thermoelectric systems, in order to establish sound technical and economical bases for selecting the design options and the development strategy of a first space nuclear power system in Europe

  19. Heat-electricity convertion systems for a Brazilian space micro nuclear reactor

    This contribution will discuss the evolution work in the development of thermal cycles to allow the development of heat-electricity conversion for the Brazilian space micro nuclear Reactor. Namely, innovative core and nuclear fuel elements, Brayton cycle, Stirling engine, heat pipes, passive multi-fluid turbine, among others. This work is basically to set up the experimental labs that will allow the specification and design of the space equipment. Also, some discussion of the cost so far, and possible other applications will be presented. (author)

  20. Space Nuclear Power Plant Pre-Conceptual Design Report, For Information

    B. Levine

    2006-01-27

    This letter transmits, for information, the Project Prometheus Space Nuclear Power Plant (SNPP) Pre-Conceptual Design Report completed by the Naval Reactors Prime Contractor Team (NRPCT). This report documents the work pertaining to the Reactor Module, which includes integration of the space nuclear reactor with the reactor radiation shield, energy conversion, and instrumentation and control segments. This document also describes integration of the Reactor Module with the Heat Rejection segment, the Power Conditioning and Distribution subsystem (which comprise the SNPP), and the remainder of the Prometheus spaceship.

  1. Heat-electricity convertion systems for a Brazilian space micro nuclear reactor

    Guimaraes, Lamartine N.F.; Marcelino, Natalia B.; Placco, Guilherme M.; Nascimento, Jamil A.; Borges, Eduardo M., E-mail: guimarae@ieav.cta.br, E-mail: lamartine.guimaraes@pq.cnpq.br, E-mail: jamil@ieav.cta.br, E-mail: jalnsgf@outlook.com, E-mail: borges.em@hotmail.com, E-mail: ecorborges@hotmail.com, E-mail: ivayolini@gmail.com, E-mail: guilherme_placco@ig.com.br [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil); Barrios Junior, Ary Garcia, E-mail: arygarcia89@yahoo.com [Faculdade de Tecnologia Sao Francisco (FATESF), Jacarei, SP (Brazil)

    2013-07-01

    This contribution will discuss the evolution work in the development of thermal cycles to allow the development of heat-electricity conversion for the Brazilian space micro nuclear Reactor. Namely, innovative core and nuclear fuel elements, Brayton cycle, Stirling engine, heat pipes, passive multi-fluid turbine, among others. This work is basically to set up the experimental labs that will allow the specification and design of the space equipment. Also, some discussion of the cost so far, and possible other applications will be presented. (author)

  2. A Programmatic and Engineering Approach to the Development of a Nuclear Thermal Rocket for Space Exploration

    Bordelon, Wayne J., Jr.; Ballard, Rick O.; Gerrish, Harold P., Jr.

    2006-01-01

    With the announcement of the Vision for Space Exploration on January 14, 2004, there has been a renewed interest in nuclear thermal propulsion. Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions; however, the cost to develop a nuclear thermal rocket engine system is uncertain. Key to determining the engine development cost will be the engine requirements, the technology used in the development and the development approach. The engine requirements and technology selection have not been defined and are awaiting definition of the Mars architecture and vehicle definitions. The paper discusses an engine development approach in light of top-level strategic questions and considerations for nuclear thermal propulsion and provides a suggested approach based on work conducted at the NASA Marshall Space Flight Center to support planning and requirements for the Prometheus Power and Propulsion Office. This work is intended to help support the development of a comprehensive strategy for nuclear thermal propulsion, to help reduce the uncertainty in the development cost estimate, and to help assess the potential value of and need for nuclear thermal propulsion for a human Mars mission.

  3. NASA safety program activities in support of the Space Exploration Initiatives Nuclear Propulsion program

    Sawyer, J. C., Jr.

    1993-01-01

    The activities of the joint NASA/DOE/DOD Nuclear Propulsion Program Technical Panels have been used as the basis for the current development of safety policies and requirements for the Space Exploration Initiatives (SEI) Nuclear Propulsion Technology development program. The Safety Division of the NASA Office of Safety and Mission Quality has initiated efforts to develop policies for the safe use of nuclear propulsion in space through involvement in the joint agency Nuclear Safety Policy Working Group (NSPWG), encouraged expansion of the initial policy development into proposed programmatic requirements, and suggested further expansion into the overall risk assessment and risk management process for the NASA Exploration Program. Similar efforts are underway within the Department of Energy to ensure the safe development and testing of nuclear propulsion systems on Earth. This paper describes the NASA safety policy related to requirements for the design of systems that may operate where Earth re-entry is a possibility. The expected plan of action is to support and oversee activities related to the technology development of nuclear propulsion in space, and support the overall safety and risk management program being developed for the NASA Exploration Program.

  4. Multilayer Scintillation Detector for Nuclear Physics Monitoring of Space Weather

    Batischev, A. G.; Aleksandrin, S. Yu.; Gurov, Yu. B.; Koldashov, S. V.; Lapushkin, S. V.; Mayorov, A. G.

    The physical characteristics of the multilayer scintillation spectrometer (MSS) for identification and energy measurement of cosmic electrons, positrons and nuclei are considered in this paper. This spectrometer is made on the basis of several plastic scintillator plates with various thick viewed by photomultipliers. Two upper layers are strips of orthogonal scintillators. The nuclei energy measurement range is 3 - 100 MeV/nucleon. Spectrometer is planning for space weather monitoring and investigation of solar-magnetospheric and geophysics effects on satellite. MSS time resolution is about 1 microsecond and it can measure the time profiles of fast processes in the Earth's magnetosphere. Spectrometer experimental characteristics were estimated by means of computer simulation. The ionization loss fluctuations, ion charge exchange during pass through detector and, especially, scintillation quenching effect (Bircs effect) were taken into account in calculations.

  5. Instrumentation and controls evaluation for space nuclear power systems

    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

  6. Instrumentation and Controls evaluation for space nuclear power systems

    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

  7. The outlook for application of powerful nuclear thermionic reactor -powered space electric jet propulsion engines

    This paper summarizes main study results for application of powerful space electric jet propulsion unit (EJPUs) which is powered by Nuclear Thermionic Power Unit (NTPU). They are combined in Nuclear Power/Propulsion Unit (NPPU) which serves as means of spacecraft equipment power supply and spacecraft movement. Problems the paper deals with are the following: information satellites delivery and their on-orbit power supply during 10-15 years, removal of especially hazardous nuclear wastes, mining of asteroid resources and others. Evaluations on power/time/mass relationship for this type of mission are given. EJPU parameters are compatible with Russian existent or being under development launch vehicle. (author)

  8. The outlook for application of powerful nuclear thermionic reactor - powered space electric jet propulsion engines

    Semyonov, Y.P.; Bakanov, Y.A.; Synyavsky, V.V.; Yuditsky, V.D. [Rocket-Space Corp. `Energia`, Moscow (Russian Federation)

    1997-12-31

    This paper summarizes main study results for application of powerful space electric jet propulsion unit (EJPUs) which is powered by Nuclear Thermionic Power Unit (NTPU). They are combined in Nuclear Power/Propulsion Unit (NPPU) which serves as means of spacecraft equipment power supply and spacecraft movement. Problems the paper deals with are the following: information satellites delivery and their on-orbit power supply during 10-15 years, removal of especially hazardous nuclear wastes, mining of asteroid resources and others. Evaluations on power/time/mass relationship for this type of mission are given. EJPU parameters are compatible with Russian existent or being under development launch vehicle. (author)

  9. Heat resistant materials and their feasibility issues for a space nuclear transportation system

    A number of nuclear propulsion concepts based on solid-core nuclear propulsion are being evaluated for a nuclear propulsion transportation system to support the Space Exploration Initiative (SEI) involving the reestablishment of a manned lunar base and the subsequent exploration of Mars. These systems will require high-temperature materials to meet the operating conditions with appropriate reliability and safety built into these systems through the selection and testing of appropriate materials. The application of materials for nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP) systems and the feasibility issues identified for their use will be discussed. Some mechanical property measurements have been obtained, and compatibility tests were conducted to help identify feasibility issues. 3 refs., 1 fig., 4 tabs

  10. An interagency space nuclear propulsion safety policy for SEI - Issues and discussion

    Marshall, A. C.; Sawyer, J. C., Jr.

    1991-01-01

    An interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of Safety Functional Requirements. In addition, the NSPWG reviewed safety issues for nuclear propulsion and recommended top level safety requirements and guidelines to address these issues. Safety topics include reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations. In this paper the emphasis is placed on the safety policy and the issues and considerations that are addressed by the NSPWG recommendations.

  11. Simple Nuclear Excitations Distributed among Closely Spaced Levels

    A review is given of the limited information available about the correct description of simple nuclear excitations when they are mixed with more complicated excitations to form the quasi-stationary highly excited states of nuclei. Examples are given which illustrate the energy region over which a simple excitation appears, the existence of local variations or intermediate structure with a characteristic energy of about 100 keV, and correlations which might exist between two different simple excitations. The types of simple excitations considered are single-particle states, analogue states, and electric dipole excitation. There is little quantitative information about the gross spreading of single-particle strength despite the successes of the optical model and the popularity of transfer reactions. There may be some evidence for intermediate structure in reported variations of neutron scattering cross-sections, but the interpretation is ambiguous. A convincing and educational example of a single-particle ''doorway'' is given by the Monahan and Elwyn analysis of s-wave neutron resonances in Fe. The fragmentation of an analogue state among the T90Y) can be obtained by studying the more easily seen corresponding analogues (e.g. in 90Zr). Information on the spreading of electric dipole strength can be obtained directly from gamma-ray interaction cross-sections. The non-statistical neutrons emitted from the giant dipole resonance provide guidance for the theoretical description of the resonance. At energies well below the giant resonance there is evidence for substantial intermediate structure. In the same energy region comparisons between (γ, γ) and (γ, Po) cross-sections are particularly sensitive to correlations. Many more relevant experiments will be needed before the spreading of strength and the correlations between different simple excitations are understood. (author)

  12. United Nations deliberations of the use of nuclear power sources in space: 1978-1987

    Bennett, Gary L.; Sholtis, Joseph A., Jr.; Rashkow, Bruce C.

    1988-01-01

    The United Nations (U.N.) is continuing its deliberations on the use of nuclear power sources (NPS) in space. Although no complete set of legal principles has yet been agreed upon, certain scientific and technical criteria for the safe design and use of NPS have been accepted. In this respect, it should be noted that in its 1981 report, the Working Group on the Use of Power Sources in Outer Space concluded that power sources can be used safely in outer space, provided that all necessary safety requirements are met. This is also a succinct statement of the U.S. position.

  13. Space nuclear power studies in France - overview of the Erato program

    A cooperative program about nuclear space power systems has been initiated in 1982 by both CNES (Centre National d'Etudes Spatiales) and CEA (Commissariat a l'Energie Atomique) with a view to assessing the feasibility, the lead time, and the cost of nuclear space power systems of the 20 to 400 kWe class. A first study phase, completed in mid 1986, has been devoted to preliminary feasibility and cost studies of a reference 200 kWe turboelectric power system ERATO compatible with the ARIANE V launcher. The present three-year study phase is mainly oriented toward the assessment of the potential advantages of nuclear power systems over solar dynamic and photovoltaic systems, within the 20 kWe power range, which corresponds to the expected power needs of the first european space missions. This paper is intended to give an overview of the present program phase, with emphasis on the design studies dedicated to three concepts of 20 kWe nuclear turboelectric power systems selected for comparison against non nuclear power systems

  14. Determination of Important Nuclear Fragmentation Processes for Human Space Radiation Protection

    Lin, Zi-Wei

    2007-01-01

    We present a semi-analytical method to determine which partial cross sections of nuclear fragmentations most affect the shielded dose equivalent due to exposure to galactic cosmic rays. The cross sections thus determined will require more theoretical and/or experimental studies in order for us to better predict, reduce and mitigate the radiation exposure in human space explorations.

  15. Investigations of IPPE thermophysicists in the field of space nuclear power facilities

    The history of space nuclear power facilities development in IPPE is considered. The main attention is paid to coolant choice; development of demonstration high-temperature lithium benches, acquisition of equipment and safe working methods; working out of physicochemical fundamentals of core coolants use, their technology, study of coolant physicochemical properties

  16. Analysis of nuclear waste disposal in space, phase 3. Volume 1: Executive summary of technical report

    Rice, E. E.; Miller, N. E.; Yates, K. R.; Martin, W. E.; Friedlander, A. L.

    1980-01-01

    The objectives, approach, assumptions, and limitations of a study of nuclear waste disposal in space are discussed with emphasis on the following: (1) payload characterization; (2) safety assessment; (3) health effects assessment; (4) long-term risk assessment; and (5) program planning support to NASA and DOE. Conclusions are presented for each task.

  17. SPACE-R nuclear power system SC-320 thermionic fuel element performance tests

    In 1993 and 1994, the Russian Scientific Research Institute NII NPO ''LUCH'' and Space Power, Inc., (SPI), of San Jose, California, developed a prototype of the single-cell thermionic fuel element (TFE) for the SPACE-R space nuclear power system (NPS). The SPACE-R system was designed as a part of the US Department of Energy's (DOE) Space Reactor Development Program to develop a long life, space reactor system capable of supplying up to 40 kW(e) output power. The jointly developed SC-320 TFE is a prototype of the next generation thermionic converter for nuclear applications in space. This paper presents the results of the initial demonstration tests and subsequent parametric evaluations conducted on the SC-320 TFE as compared to the calculated performance characteristics. The demonstration tests were conducted jointly by Russian and American specialists at the Thermionic Evaluation Facility (TEF) at the New Mexico Engineering Research Institute (NMERI) of the University of New Mexico in Albuquerque

  18. Nuclear structure theory in spin- and number-conserving quasiparticle configuration spaces: First applications

    Schmid, K.W.; Gruemmer, F.; Faessler, A.

    1984-01-01

    In the first part of the present series of two papers we discussed several nuclear structure models all working in configuration spaces consisting of spin- and number-projected quasiparticle determinants. In the present paper a particular version of the numerically simplest of these models is presented. This model approximates the nuclear wave functions by linear combinations of the angular momentum- and particle number-projected Hartree-Fock-Bogoliubov vacuum and the equally spin- and number-projected two quasiparticle excitations with respect to it. The model allows the use of realistic two body interactions and rather large model spaces. It can hence be applied to a large number of nuclear structure problems in various mass regions. First applications have been performed for the nuclei /sup 20/Ne, /sup 22/Ne, /sup 46/Ti, and /sup 164/Er. In all these cases the results are very encouraging.

  19. Application of Recommended Design Practices for Conceptual Nuclear Fusion Space Propulsion Systems

    Williams, Craig H.

    2004-01-01

    An AIAA Special Project Report was recently produced by AIAA's Nuclear and Future Flight Propulsion Technical Committee and is currently in peer review. The Report provides recommended design practices for conceptual engineering studies of nuclear fusion space propulsion systems. Discussion and recommendations are made on key topics including design reference missions, degree of technological extrapolation and concomitant risk, thoroughness in calculating mass properties (nominal mass properties, weight-growth contingency and propellant margins, and specific impulse), and thoroughness in calculating power generation and usage (power-flow, power contingencies, specific power). The report represents a general consensus of the nuclear fusion space propulsion system conceptual design community and proposes 15 recommendations. This paper expands on the Report by providing specific examples illustrating how to apply each of the recommendations.

  20. Space nuclear power system and the design of the nuclear electric propulsion OTV

    Payload increases of three to five times that of the Shuttle/Centaur can be achieved using nuclear electric propulsion. Various nuclear power plant options being pursued by the SP-100 Program are described. These concepts can grow from 100 kW/sub e/ to 1MW/sub e/ output. Spacecraft design aspects are addressed, including thermal interactions, plume interactions, and radiation fluences. A baseline configuration is described accounting for these issues. Safety aspects of starting the OTV transfer from an altitude of 300 km indicate no significant additional risk to the biosphere

  1. Effluent Containment System for space thermal nuclear propulsion ground test facilities

    This report presents the research and development study work performed for the Space Reactor Power System Division of the U.S. Department of Energy on an innovative ECS that would be used during ground testing of a space nuclear thermal rocket engine. A significant portion of the ground test facilities for a space nuclear thermal propulsion engine are the effluent treatment and containment systems. The proposed ECS configuration developed recycles all engine coolant media and does not impact the environment by venting radioactive material. All coolant media, hydrogen and water, are collected, treated for removal of radioactive particulates, and recycled for use in subsequent tests until the end of the facility life. Radioactive materials removed by the treatment systems are recovered, stored for decay of short-lived isotopes, or packaged for disposal as waste. At the end of the useful life, the facility will be decontaminated and dismantled for disposal

  2. Shutdown and degradation: Space computers for nuclear application, verification of radiation hardness. Final report

    (1) Employment of those radiation hard electronics which are already known in military and space applications. (2) The experience in space-flight shall be used to investigate nuclear technology areas, for example, by using space electronics to prove the range of applications in nuclear radiating environments. (3) Reproduction of a computer developed for telecommunication satellites; proof of radiation hardness by radiation tests. (4) At 328 Krad (Si) first failure of radiation tolerant devices with 100 Krad (Si) hardness guaranteed. (5) Using radiation hard devices of the same type you can expect applications at doses of greater than 1 Mrad (Si). Electronic systems applicable for radiation categories D, C and lower part of B for manipulators, vehicles, underwater robotics. (orig.)

  3. Effluent Containment System for space thermal nuclear propulsion ground test facilities

    NONE

    1995-08-01

    This report presents the research and development study work performed for the Space Reactor Power System Division of the U.S. Department of Energy on an innovative ECS that would be used during ground testing of a space nuclear thermal rocket engine. A significant portion of the ground test facilities for a space nuclear thermal propulsion engine are the effluent treatment and containment systems. The proposed ECS configuration developed recycles all engine coolant media and does not impact the environment by venting radioactive material. All coolant media, hydrogen and water, are collected, treated for removal of radioactive particulates, and recycled for use in subsequent tests until the end of the facility life. Radioactive materials removed by the treatment systems are recovered, stored for decay of short-lived isotopes, or packaged for disposal as waste. At the end of the useful life, the facility will be decontaminated and dismantled for disposal.

  4. Radiation risk from the nuclear power installation of space vehicle in case of reentry to the atmosphere

    Main directions of space using of nuclear power are considered. Nuclear energy has found many applications in space projects. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear power for propulsion purposes in space flight. History of usage nuclear power systems in space technic is shown. Today there are 54 satellites with NPS in space near the Earth. The main principle of radical solution of the problem of radiation safety is based on the accommodation of space objects with nuclear units in orbits, such that the ballistic lifetime is greater than the time necessary for complete decay of the accumulated radioactivity. Radiation safety on various stages of space nuclear systems exploitation is discussed. If Main System Ensuring Radiation Safety is failed, it must operates Reserved System Ensuring Radiation Safety. Concrete development of a booster system for nuclear unit and a system for the reactor destruction in order to ensure aerodynamic destruction of fuel has been realized in satellite of 'Cosmos' series. The investigations on reserved system ensuring radiation safety in Moscow Physical - Engineering Institute are discussed. The results show that we can in principle ensure the radiation safety in accordance to ICRP recommendations. (author)

  5. Design of an Annular Linear Induction Pump for Nuclear Space Applications

    The United States Department of Energy's (DOE) Office of Nuclear Energy, Science, and Technology is supporting the National Aeronautics and Space Administration (NASA) in evaluating space mission power, propulsion systems and technologies to support the implementation of the Vision for Space Exploration (VSE). NASA will need increased power for propulsion and for surface power applications to support both robotic and human space exploration missions. As part of the Fission Surface Power Technology Project for the development of nuclear reactor technologies for multi-mission spacecrafts, an Annular Linear Induction Pump, a type of Electromagnetic Pump for liquid metals, able to operate in space has to be designed. Results of such design work are described as well as the fundamental ideas behind the development of an optimized design methodology. This project, which is a collaboration between Idaho National Laboratory (INL), Pacific Northwest National Laboratory (PNNL) and Marshall Space Flight Center (MSFC), involves the use of theoretical, computational and experimental tools for multi-physics analysis as well as advanced engineering design methods and techniques.

  6. Reasons for nuclear forces in light of the constitution of the real space

    Krasnoholovets, Volodymyr

    2011-01-01

    The concept of microstructure of the real space, considered as a mathematical lattice of cells (the tessel-lattice), and notions of canonical particles and fields, which are generated by the space, are analyzed. Submicroscopic mechanics based on this concept is discussed and employed for in-depth study of the nucleon-nucleon interaction. It is argued that a deformation coat is developed in the real space around the nucleon (as is the case with any other canonical particle such as electron, muon, etc.) and that they are the deformation coats that are responsible for the appearance of nuclear forces. One more source of nuclear forces is associated with inerton clouds, excitations of the space tessel-lattice (the excitations are a substructure of nucleons' matter waves), which accompany moving nucleons as in the case of any other canonical particles. Two nuclear systems are under consideration: the deuteron and a weight nucleus. It is shown that a weight nucleus is a cluster of interacting protons and neutrons. ...

  7. Space-time picture of relativistic nuclear collisions and its manifestation in the secondary particle spectra

    High-energy nuclear collision mechanisms are studied and description possibility of these processes space-time pattern within the scope of partial transparency models (PTM), hydrodynamic model (HDM) and internuclear cascade model (INC) is considered. Analysis of theoretical predictions and experemental data for proton inclusive spectra from 12C+12C reaction witn Elab=3.6 GeV/nucleon and angular dependencies of proton yield in this reaction, from 20Ne+20Ne reaction with Elab=2.1 GeV/nucleon within central collision region, is carried out. Universality origin problem of proton inclusive spectra producting in nucleus-nuclear and hadron-nuclear collisions is considered. Compared analysis shows, that PTM, HDM and INC-models explain the rapidity distributions universal behaviour within the target fragmentation region. Description deficiencies of proton spectra universality in the used models are marked. Nuclear system properties, such as excitation and decay of spectator parts of nuclei spectator matter fragmentation, with ∼10 MeV/nucleon are considered. The conducted analysis showed, that proton inclusive spectra in collisions of similar nuclei are sensitive to model effects with collision initial energy rise. This sensitivity manifests especially in the inclusive spectra rapidity representation. It is noted, that the realistic space-time pattern of realistic nuclear collisions is described well by PTM, HDM and INC models

  8. General-purpose heat source project and space nuclear safety fuels program. Progress report, February 1980

    This formal monthly report covers the studies related to the use of 238PuO2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are: General-Purpose Heat Source Development and Space Nuclear Safety and Fuels. Most of the studies discussed here are of a continuing nature. Results and conclusions described may change as the work continues. Published reference to the results cited in this report should not be made without the explicit permission of the person in charge of the work

  9. Review of the Tri-Agency Space Nuclear Reactor Power System Technology Program

    The Space Nuclear Reactor Power System Technology Program designated SP-100 was created in 1983 by NASA, the U.S. Department of Defense, and the Defense Advanced Research Projects Agency. Attention is presently given to the development history of SP-100 over the course of its first year, in which it has been engaged in program objectives definition, the analysis of civil and military missions, nuclear power system functional requirements definition, concept definition studies, the selection of primary concepts for technology feasibility validation, and the acquisition of initial experimental and analytical results

  10. Preliminary risk assessment for nuclear waste disposal in space. Volume I. Executive summary of technical report

    Three major conclusions come from this preliminary risk assessment of nuclear waste disposal in space. Preliminary estimates of space disposal risk are low, even with the estimated uncertainty bounds. If calculated mined geologic repository (MGR) release risks remain low, and the EPA requirements continue to be met, then no additional space disposal study effort is warranted. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as an MGR complement is warranted. As a result of this study, the following recommendations are made to NASA and the US DOE: During the continued evaluation of the mined geologic repository risk over the years ahead by DOE, if any significant increase in the calculated health risk is predicted for the MGR, then space disposal should be reevaluated at that time. The risks perceived by the public for the MGR should be evaluated on a broad basis by an independent organization to evaluate acceptance. If, in the future, MGR risks are found to be significant due to some presently unknown technical or social factor, and space disposal is selected as an alternative that may be useful in mitigating the risks, then the following space disposal study activities are recommended: improvement in chemical processing technology for wastes; payload accident response analysis; risk uncertainty analysis for both MGR and space disposal; health risk modeling that includes pathway and dose estimates; space disposal cost modeling; assessment of space disposal perceived (by public) risk benefit; and space systems analysis supporting risk and cost modeling

  11. Space and Terrestrial Power System Integration Optimization Code BRMAPS for Gas Turbine Space Power Plants With Nuclear Reactor Heat Sources

    Juhasz, Albert J.

    2007-01-01

    In view of the difficult times the US and global economies are experiencing today, funds for the development of advanced fission reactors nuclear power systems for space propulsion and planetary surface applications are currently not available. However, according to the Energy Policy Act of 2005 the U.S. needs to invest in developing fission reactor technology for ground based terrestrial power plants. Such plants would make a significant contribution toward drastic reduction of worldwide greenhouse gas emissions and associated global warming. To accomplish this goal the Next Generation Nuclear Plant Project (NGNP) has been established by DOE under the Generation IV Nuclear Systems Initiative. Idaho National Laboratory (INL) was designated as the lead in the development of VHTR (Very High Temperature Reactor) and HTGR (High Temperature Gas Reactor) technology to be integrated with MMW (multi-megawatt) helium gas turbine driven electric power AC generators. However, the advantages of transmitting power in high voltage DC form over large distances are also explored in the seminar lecture series. As an attractive alternate heat source the Liquid Fluoride Reactor (LFR), pioneered at ORNL (Oak Ridge National Laboratory) in the mid 1960's, would offer much higher energy yields than current nuclear plants by using an inherently safe energy conversion scheme based on the Thorium --> U233 fuel cycle and a fission process with a negative temperature coefficient of reactivity. The power plants are to be sized to meet electric power demand during peak periods and also for providing thermal energy for hydrogen (H2) production during "off peak" periods. This approach will both supply electric power by using environmentally clean nuclear heat which does not generate green house gases, and also provide a clean fuel H2 for the future, when, due to increased global demand and the decline in discovering new deposits, our supply of liquid fossil fuels will have been used up. This is

  12. Nuclear Physics and Radiobiology - Issues for Humans in Space and on Earth

    Tripathi, Ram

    2008-10-01

    Nuclear physics is playing a vital role in human biological applications, specifically in planned space missions, in hadron radiotherapy, and in low dose radiobiology. While seemingly disparate, these and other areas share a common need for the understanding of nuclear interactions in biological systems. Radiobiology continues to provide valuable information that will help develop better methods for using radiation in the treatment of disease as well as provide a scientific basis for radiation protection standards. NASA is now focused on the agency's vision for space exploration encompassing a broad range of human and robotic missions including missions to the Moon, Mars and beyond. As a result, there is a focus on long duration space missions. Protection from hazards of space radiation has been identified as one of the five NASA critical areas for human space flight. The cost effective design of spacecraft demands a very stringent requirement on the optimization process. Exposures from the hazards of severe space radiation in deep space and/or long duration missions are very different from that of low earth orbit, and much needs to be done about their effects. However, it is clear that revolutionary technologies will need to be developed. Here on earth, particulate radiation treatment for cancer, such as proton radiotherapy, is playing an increasing important role, while the biological effectiveness remains less well understood than for x-rays and other forms of medical radiation treatments. Advanced imaging, dosimetric, Monte Carlo, and other techniques from nuclear physics are utilized to study the molecular basis of fractionation dependency and other tumor and normal tissue radiation responses, such as radiosensitivity. Moreover, advances developed by biological research efforts, such as the sequencing of the human genome, have opened new horizons for radiobiology. New techniques have made it possible to determine at the cellular / molecular level how living

  13. Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion

    Williams, Craig H.; Dudzinski, Leonard A.; Borowski, Stanley K.; Juhasz, Albert J.

    2005-01-01

    A conceptual vehicle design enabling fast, piloted outer solar system travel was created predicated on a small aspect ratio spherical torus nuclear fusion reactor. The initial requirements were satisfied by the vehicle concept, which could deliver a 172 mt crew payload from Earth to Jupiter rendezvous in 118 days, with an initial mass in low Earth orbit of 1,690 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including artificial gravity payload, central truss, nuclear fusion reactor, power conversion, magnetic nozzle, fast wave plasma heating, tankage, fuel pellet injector, startup/re-start fission reactor and battery bank, refrigeration, reaction control, communications, mission design, and space operations. Detailed fusion reactor design included analysis of plasma characteristics, power balance/utilization, first wall, toroidal field coils, heat transfer, and neutron/x-ray radiation. Technical comparisons are made between the vehicle concept and the interplanetary spacecraft depicted in the motion picture 2001: A Space Odyssey.

  14. Comments on dual-mode nuclear space power and propulsion system concepts

    Some form of Dual-Mode Nuclear Space Power ampersand Propulsion System (D-MNSP ampersand PS) will be essential to spacefaring throughout teh solar system and that such systems must evolve as mankind moves into outer space. The initial D-MNPSP ampersand PS Reference System should be based on (1) present (1990), and (2) advanced (1995) technology for use on comparable mission in the 2000 and 2005 time period respectively. D-MNSP ampersand PS can be broken down into a number of subsystems: Nuclear subsystems including the energy source and controls for the release of thermal power at elevated temperatures; power conversion subsystems; waste heat rejection subsystems; and control and safety subsystems. These systems are briefly detailed

  15. Causes and advantages of radical innovation: example of the space nuclear propulsion

    After a review of the principles underlying the nuclear propulsion and its application to space propulsion, the NERVA program, developed in the US in the 60's, is summarized, with emphasis on the fuels that were studied in order to sustain very high temperature and variations (graphite matrix with uranium and zirconium carbides), and on the reactor design which led to the development of the PHOEBUS 2A reactor, the most powerful reactor ever constructed (4000 MW). Advantages of the nuclear propulsion for space transportation are still prominent, especially for a Moon permanent base and voyages to Mars. French researches are aimed at a cargo shuttle application between Earth and Moon orbits, with a reactor concept based on annular fuel elements and hydrogen radially passing through the fuel elements

  16. Thermal control of high energy nuclear waste, space option. [mathematical models

    Peoples, J. A.

    1979-01-01

    Problems related to the temperature and packaging of nuclear waste material for disposal in space are explored. An approach is suggested for solving both problems with emphasis on high energy density waste material. A passive cooling concept is presented which utilized conduction rods that penetrate the inner core. Data are presented to illustrate the effectiveness of the rods and the limit of their capability. A computerized thermal model is discussed and developed for the cooling concept.

  17. The “Flying Carpet” concept: A possible alternative to nuclear space propulsion

    Meyer, Rudolf X.

    2006-05-01

    This paper examines the potential performance of a new concept for very high specific impulse propulsion for scientific explorations beyond the solar system. The concept is based on an ultra-light weight solar-electric membrane that is deployed, stretched, stabilized, and oriented by small electric thrusters at its corners. The potential performance is found to be greatly superior to what can be achieved by multiple planetary flybys. The concept is viewed as an alternative to nuclear space propulsion.

  18. Fractality in momentum space: a signal of criticality in nuclear collisions

    Antoniou, Nikolaos G; Diakonos, Fotios K

    2015-01-01

    We show that critical systems of finite size develop a fractal structure in momentum space with anomalous dimension given in terms of the isotherm critical exponent delta of the corresponding infinite system. The associated power laws of transverse momentum correlations, in high-energy nuclear collisions, provide us with a signature of a critical point in strongly interacting matter according to the laws of QCD.

  19. A configuration space Monte Carlo algorithm for solving the nuclear pairing problem

    Lingle, Mark

    Nuclear pairing correlations using Quantum Monte Carlo are studied in this dissertation. We start by defining the nuclear pairing problem and discussing several historical methods developed to solve this problem, paying special attention to the applicability of such methods. A numerical example discussing pairing correlations in several calcium isotopes using the BCS and Exact Pairing solutions are presented. The ground state energies, correlation energies, and occupation numbers are compared to determine the applicability of each approach to realistic cases. Next we discuss some generalities related to the theory of Markov Chains and Quantum Monte Carlo in regards to nuclear structure. Finally we present our configuration space Monte Carlo algorithm starting from a discussion of a path integral approach by the authors. Some general features of the Pairing Hamiltonian that boost the effectiveness of a configuration space Monte Carlo approach are mentioned. The full details of our method are presented and special attention is paid to convergence and error control. We present a series of examples illustrating the effectiveness of our approach. These include situations with non-constant pairing strengths, limits when pairing correlations are weak, the computation of excited states, and problems when the relevant configuration space is large. We conclude with a chapter examining some of the effects of continuum states in 24O.

  20. Economic comparison of an improved nuclear filter system considering space, operation, testing, and maintenance costs

    The development of an all-welded charcoal adsorber design for increased system iodine removal efficiency has provided certain other unique advantages of particular interest to nuclear power plant personnel involved in health/safety, operation, maintenance, testing and space allocation for nuclear filter systems. The design features providing these unique advantages have been refined and tested and are available and installed on operating reactors as the HECA filter system. Health/safety aspects of the system are improved through the use of a unique pneumatic conveying system which eliminates the need for entrance of maintenance personnel into the filter housing during removal and replacement of spent charcoal and; thereby, minimizes radiation exposure of occupational personnel. Operational and maintenance costs, after capital investment, for nuclear filter systems being of particular interest to utility operations management are compared with conventional iodine absorber systems. The material cost savings in charcoal replacement with the system can exceed capital investment costs for given operating conditions. Testing and retest for by-pass leakage location and correction experiences are described and comparisons drawn between the HECA system and conventional designs. Space allocation improvements for actual nuclear filter system installations are described using the HECA system in conjunction with 1500 CFM ''superflow'' absolute filter modules. Features of the separatorless absolute superflow filter that complement the like design features of the all-welded HECA charcoal adsorber are described and operational and test data are presented. (U.S.)

  1. Nuclear power supplies: their potential and the practical problems to their achievement for space missions

    The anticipated growth of the space station power requirement provides a good example of the problem the space nuclear power supply developers have to contend with: should a reactor power supply be developed that attempts to be all things to all missions, i.e., is highly flexible in its ability to meet a wide variety of missions, or should the development of a reactor system await a specific mission definition and be customized to this mission. This leads, of course, to a chicken-and-egg situation. For power requirements of several hundreds of kilowatts or more, no nuclear power source exists or is even far enough along in the definition stage (much less the development stage) for NASA to reasonably assume probable availability within the next 10 years. The real problem of space nuclear power is this ''chicken-and-egg'' syndrome: DOE will not develop a space reactor system for NASA without a firm mission, and NASA will not specify a firm mission requiring a space reactor because such a system doesn't exist and is perceived not to be developable within the time frame of the mission. The problem is how to break this cycle. The SP-100 program has taken an important first step to breaking this cycle, but this program is much more design-specific than what is required to achieve a broad technology base and latitude in achievable power level. In contrast to the SP-100 approach, a wider perspective is required: the development of the appropriate technologies for power levels can be broken into ranges, say, from 100 kWe to 1000 kWe, and from 1000 kWe to 10,000 kWe

  2. Space nuclear power studies in France. - A new concept of particle bed reactor

    A cooperative program about space nuclear turboelectric space power systems was initiated in 1982 by both the Centre National d'Etudes Spatiales (CNES) and the Commissariat a l'Energie Atomique (CEA) agencies of the French government, with a view to assessing the feasibility, the lead time and the cost for the development of nuclear space power systems relevant to the power range of 20 to 400 kWe. The effort on conceptual studies recently shifted towards low power systems (20 kWe). In order to widely cover the range of possible technologies for the 20-kWe space power systems, and to assess the impact of the reactor concept (liquid metal versus gas cooled) and of the relevant operating temperature upon the system performances, a set of three reference turboelectric systems were selected for comparison. Those considered for both extreme bounds of the explored range of maximum heat source temperature (970 K and 1470 K), use a liquid metal cooled reactor (sodium or Nak and lithium respectively) and the basic features of the 200 kWe system. In addition to both liquid metal cooled systems, a third system using a gas cooled epithermal particle bed reactor, to drive a direct cycle conversion system with a turbine inlet temperature of 1120 K is being investigated; this system is intended to make full use of the heat resisting materials and of the techniques, which have been developed for the high temperature gas cooled reactors

  3. Fast computerized technology for optimizing logging spacing and devising metrological and interpretation means for nuclear logs

    Presented is a beta-version of computerized technology for interactive modeling ('mathematical workbench') of the following phases of designing the nuclear logging tools: 1. Optimization of spacings and measurement modes of nuclear logging systems; 2. Interpretation and theoretical-and-metrological support of existing and future logging systems; 3. Assessing the efficiency of different nuclear logging systems under new geological and technical conditions. The technology is presented as an integrated software package of applied programs DELTA which includes: (i) a graphical interface providing the problem statement, data input/output, and a control to solution of problems 1-3; (ii) a package of applied programs POLE which provides fast 3-D on-line numerical modeling of nuclear-geophysical fields and vectorization of solutions in a given range of geological and technical well logging conditions (intelligence core of the package with solvers of direct problems); (iii) a set of problem-oriented processing programs which allow one to calculate necessary functionals from modeled radiation fields - response of logging tools, partial and complete errors of a sought formation parameter and target functions, solve problems 1-3 and output the results. The present version of package DELTA covers all the methods and modifications of nuclear logging: thermal NNL, epithermal NNL, multispaced NNL, NGL, PNNL-M, and C/O log in vertical, inclined, and horizontal wells. DELTA offers the following functional capabilities in making the optimization of a nuclear log: (i) selection of an arbitrary set of sought characteristics of spacing: number and length of spacing, type and sensitive zone of detectors, spectrum and yield of a source, material of a screen, position and width of recording channels, etc.; (ii) solution of optimization problems for arbitrary geological and technical conditions, including horizontal wells, with due regard of invasion zone, casing, etc.; (iii) high efficient

  4. Analysis of nuclear waste disposal in space, phase 3. Volume 2: Technical report

    Rice, E. E.; Miller, N. E.; Yates, K. R.; Martin, W. E.; Friedlander, A. L.

    1980-01-01

    The options, reference definitions and/or requirements currently envisioned for the total nuclear waste disposal in space mission are summarized. The waste form evaluation and selection process is documented along with the physical characteristics of the iron nickel-base cermet matrix chosen for disposal of commercial and defense wastes. Safety aspects of radioisotope thermal generators, the general purpose heat source, and the Lewis Research Center concept for space disposal are assessed as well as the on-pad catastrophic accident environments for the uprated space shuttle and the heavy lift launch vehicle. The radionuclides that contribute most to long-term risk of terrestrial disposal were determined and the effects of resuspension of fallout particles from an accidental release of waste material were studied. Health effects are considered. Payload breakup and rescue technology are discussed as well as expected requirements for licensing, supporting research and technology, and safety testing.

  5. Reflected kinetics model for nuclear space reactor kinetics and control scoping calculations

    The objective of this research is to develop a model that offers an alternative to the point kinetics (PK) modelling approach in the analysis of space reactor kinetics and control studies. Modelling effort will focus on the explicit treatment of control drums as reactivity input devices so that the transition to automatic control can be smoothly done. The proposed model is developed for the specific integration of automatic control and the solution of the servo mechanism problem. The integration of the kinetics model with an automatic controller will provide a useful tool for performing space reactor scoping studies for different designs and configurations. Such a tool should prove to be invaluable in the design phase of a space nuclear system from the point of view of kinetics and control limitations

  6. Human factors and nuclear space technology in long-term exploration

    Brown-VanHoozer, S.A.; VanHoozer, W.R.

    2000-07-01

    Allocation of manual versus automated tasks for operation and maintenance of nuclear power systems in space will be crucial at the onset and at the return of a space flight. Such factors as space adaptation syndrome (SAS), a temporary space motion sickness that has affected 40 to 50% of crew members on past space flights, can result in lost effort ranging from a few hours to a full day. This could have a significant impact on manual performance where high levels of execution are likely to be required in the very early stages of the mission. Other considerations involving higher-level behavioral phenomena such as interpersonal and group processes, individual belief systems, social and motivational factors, and (subjective) cognitive function have received little attention; nevertheless these will be essential elements for success in long-term exploration. Understanding that long-term space flight missions may create groups that become unique societies distinct unto themselves will test current ethical, moral, and social belief systems, requiring one to examine the amalgamation as well as organizational structures for the safety and balance of the crew.

  7. Human factors and nuclear space technology in long-term exploration

    Allocation of manual versus automated tasks for operation and maintenance of nuclear power systems in space will be crucial at the onset and at the return of a space flight. Such factors as space adaptation syndrome (SAS), a temporary space motion sickness that has affected 40 to 50% of crew members on past space flights, can result in lost effort ranging from a few hours to a full day. This could have a significant impact on manual performance where high levels of execution are likely to be required in the very early stages of the mission. Other considerations involving higher-level behavioral phenomena such as interpersonal and group processes, individual belief systems, social and motivational factors, and (subjective) cognitive function have received little attention; nevertheless these will be essential elements for success in long-term exploration. Understanding that long-term space flight missions may create groups that become unique societies distinct unto themselves will test current ethical, moral, and social belief systems, requiring one to examine the amalgamation as well as organizational structures for the safety and balance of the crew

  8. Preliminary neutronic design of spock reactor: A nuclear system for space power generation

    Aim of this paper is to preliminary investigates the neutronic features of an upgrade of the MAUS [1] nuclear reactor whose core will be able to supply a thermoelectric converter in order to generate 30 kW of electricity for space applications. The neutronic layout of SPOCK (Space Power Core Ka) is a compact, MOX fuelled, liquid metal cooled and totally reflected fast reactor with a control system based on neutron absorption. Spock, that during the heart and launch operation must be maintained in sub-critical state, has to start up in the outer space at 40 K temperatures with the coolant in a solid state and it will reach the operating steady condition at the maximum temperature of 1300 K with the coolant in the liquid state. The main design goal is to maintains, in the operating conditions of a typical space mission, the control of the appropriate criticality margin versus temperature and coolant physical state. For this purpose, a neutronic/thermal-hydraulic calculation chain able to assists the entire design process must be set up. As preliminary recognition, MCNPX 2.5.0 and FLUENT calculations were carried out. The emerging key features of SPOCK are: an equilateral triangular mesh of 91 cylindrical UO2 fuel rods with a Molybdenum clad ensured by two grids of the same material, cooled by liquid Sodium and contained in an AISI 316 L vessel. The core is totally wrapped by a Beryllium reflector that hosts six absorber (B4C) rotating control rods. The reactor shape is cylindrical (radius = 30 cm and height = 60 cm) with a total mass of 275 kg. The excess reactivity was of 5000 PCM at 1300 K. A preliminary evaluation of the control rods worth and a power spatial distribution were also discussed. Through the definition of an ideal reference Keff value at 300 K for the actual SPOCK configuration, a sensitivity analysis on various cross sections data and material physical properties was performed for the given mission temperature range, allowing consideration on the

  9. High-temperature silicon-on-insulator electronics for space nuclear power systems: Requirements and feasibility

    The authors have performed a study to determine whether silicon very-large-scale integrated circuits (VLSICs) can survive the high temperature (up to 3000C) and total-dose radiation environments (up to 10 Mrad over a 7-10 year system life) projected for a very-high-power space nuclear reactor platform. It is shown that circuits built on bulk epitaxial silicon cannot meet the temperature requirement because of excessive junction leakage currents. However, circuits built on silicon-on-insulator (SOI) material can meet both the radiation and temperature requirements. From a study of interface-trap generation and annealing, they find that one cannot depend on the elevated temperatures of a space nuclear power platform to automatically improve MOS total-dose radiation hardness. Still, at high-enough temperatures (above 1750C for these devices) and long enough times postirradiation, device response can be essentially independent of total dose. Reliability and performance issues are also discussed. They find that the temperature dependence of the threshold voltage of the SOI transistors is less than that of bulk transistors. Moreover, the ''zero-temperature coefficient'' current is much smaller for these ''floating-body'' SOI devices (-- 4 μA) than for bulk devices (-- 60 μA). Survivability of high-temperature SOI VLSICs in space, including immunity to transient and single-event upset (SEU), is also addressed. While a large number of practical issues remain to be resolved, no fundamental barrier against the successful development of VLSICs on SOI for use in very-high-power space nuclear reactor systems has been identified

  10. Fabric composite radiators for space nuclear power applications. Final report, March 1993

    Klein, A.C.; Al-Baroudi, H.; Gulshan-Ara, Z.; Kiestler, W.C.; Snuggerud, R.D.; Abdul-Hamid, S.A.; Marks, T.S.

    1993-03-24

    Nuclear power systems will be required to provide much greater power levels for both civilian and defense space activities in the future than an currently needed. Limitations on the amount of usable power from radioisotope thermal generators and the limited availability of radioisotope heat source materials lead directly to the conclusion that nuclear power reactors will be needed to enhance the exploration of the solar system as well as to provide for an adequate defense. Lunar bases and travel to the Martian surface will be greatly enhanced by the use of high levels of nuclear power. Space based radar systems requiring many kilowatts of electrical power can provide intercontinental airline traffic control and defense early warning systems. Since the, figure of merit used in defining any space power system is the specific power, the decrease in die mass of any reactor system component will yield a tremendous benefit to the overall system performance. Also, since the heat rejection system of any power system can make up a large portion of the total system mass, any reduction in the mass of the heat rejection radiators will significantly affect the performance of the power system. Composite materials which combine the high strength, flexibility, and low mass characteristics of Si% based fibers with the attractive compatibility and heat transfer features of metallic foils, have been proposed for use m a number of space radiator applications. Thus, the weave of the fabric and the high strength capability of the individual fibers are combined with the high conductivity and chemical stability of a metallic liner to provide a light weight, flexible alternative to heavy, rigid, metallic radiator structural containers. The primary focus of this investigation revolves around two applications of the fabric composite materials, notably a fabric heat pipe radiator design and the Bubble Membrane Radiator concept.

  11. A Closed Brayton Power Conversion Unit Concept for Nuclear Electric Propulsion for Deep Space Missions

    Joyner, Claude Russell; Fowler, Bruce; Matthews, John

    2003-01-01

    In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload fractions and reduced mission times to the outer planets. One of the critical engineering and design aspects of nuclear electric propulsion at required mission optimized power levels is the mechanism that is used to convert the thermal energy of the reactor to electrical power. The use of closed Brayton cycles has been studied over the past 30 or years and shown to be the optimum approach for power requirements that range from ten to hundreds of kilowatts of power. It also has been found to be scalable to higher power levels. The Closed Brayton Cycle (CBC) engine power conversion unit (PCU) is the most flexible for a wide range of power conversion needs and uses state-of-the-art, demonstrated engineering approaches. It also is in use with many commercial power plants today. The long life requirements and need for uninterrupted operation for nuclear electric propulsion demands high reliability from a CBC engine. A CBC engine design for use with a Nuclear Electric Propulsion (NEP) system has been defined based on Pratt & Whitney's data from designing long-life turbo-machines such as the Space Shuttle turbopumps and military gas turbines and the use of proven integrated control/health management systems (EHMS). An integrated CBC and EHMS design that is focused on using low-risk and proven technologies will over come many of the life-related design issues. This paper will discuss the use of a CBC engine as the power conversion unit coupled to a gas-cooled nuclear reactor and the design trends relative to its use for powering electric thrusters in the 25 kWe to 100kWe power level.

  12. A closed Brayton power conversion unit concept for nuclear electric propulsion for deep space missions

    In space, whether in a stable satellite orbit around a planetary body or traveling as a deep space exploration craft, power is just as important as the propulsion. The need for power is especially important for in-space vehicles that use Electric Propulsion. Using nuclear power with electric propulsion has the potential to provide increased payload fractions and reduced mission times to the outer planets. One of the critical engineering and design aspects of nuclear electric propulsion at required mission optimized power levels is the mechanism that is used to convert the thermal energy of the reactor to electrical power. The use of closed Brayton cycles has been studied over the past 30 or years and shown to be the optimum approach for power requirements that range from ten to hundreds of kilowatts of power. It also has been found to be scalable to higher power levels. The Closed Brayton Cycle (CBC) engine power conversion unit (PCU) is the most flexible for a wide range of power conversion needs and uses state-of-the-art, demonstrated engineering approaches. It also is in use with many commercial power plants today. The long life requirements and need for uninterrupted operation for nuclear electric propulsion demands high reliability from a CBC engine. A CBC engine design for use with a Nuclear Electric Propulsion (NEP) system has been defined based on Pratt and Whitney's data from designing long-life turbo-machines such as the Space Shuttle turbopumps and military gas turbines and the use of proven integrated control/health management systems (EHMS). An integrated CBC and EHMS design that is focused on using low-risk and proven technologies will over come many of the life-related design issues. This paper will discuss the use of a CBC engine as the power conversion unit coupled to a gas-cooled nuclear reactor and the design trends relative to its use for powering electric thrusters in the 25 kWe to 100kWe power level

  13. Condition monitoring requirements for the development of a space nuclear propulsion module

    Wagner, Robert C.

    1993-01-01

    To facilitate the development of a space nuclear propulsion module for manned flights to Mars, requirements must be established early in the technology cycle. The long lead times for the acquisition of the engine system and nuclear test facilities demands that the engine system, size, performance, safety goals and condition monitoring philosophy be defined at the earliest possible time. These systems are highly complex and require a large multi-disciplinary systems engineering team to develop and track the requirements and to ensure that the as-built system reflects the intent of the mission. An effective methodology has been devised coupled with sophisticated computer tools to effectivly develop and interpret the functional requirements. These requirements can then be decomposed down to the specification level for implementation. This paper discusses the application of the methodology and the analyses to develop condition monitoring requirements under a contract with the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) Nuclear Propulsion Office (NPO).

  14. Condition monitoring requirements for the development of a space nuclear propulsion module

    Wagner, R.C.

    1993-12-31

    To facilitate the development of a space nuclear propulsion module for manned flights to Mars, requirements must be established early in the technology cycle. The long lead times for the acquisition of the engine system and nuclear test facilities demands that the engine system, size, performance, safety goals and condition monitoring philosophy be defined at the earliest possible time. These systems are highly complex and require a large multi-disciplinary systems engineering team to develop and track the requirements and to ensure that the as-built system reflects the intent of the mission. An effective methodology has been devised coupled with sophisticated computer tools to effectivly develop and interpret the functional requirements. These requirements can then be decomposed down to the specification level for implementation. This paper discusses the application of the methodology and the analyses to develop condition monitoring requirements under a contract with the National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) Nuclear Propulsion Office (NPO).

  15. Technological implications of SNAP reactor power system development on future space nuclear power systems

    Nuclear reactor systems are one method of satisfying space mission power needs. The development of such systems must proceed on a path consistent with mission needs and schedules. This path, or technology roadmap, starts from the power system technology data base available today. Much of this data base was established during the 1960s and early 1970s, when government and industry developed space nuclear reactor systems for steady-state power and propulsion. One of the largest development programs was the Systems for Nuclear Auxiliary Power (SNAP) Program. By the early 1970s, a technology base had evolved from this program at the system, subsystem, and component levels. There are many implications of this technology base on future reactor power systems. A review of this base highlights the need for performing a power system technology and mission overview study. Such a study is currently being performed by Rockwell's Energy Systems Group for the Department of Energy and will assess power system capabilities versus mission needs, considering development, schedule, and cost implications. The end product of the study will be a technology roadmap to guide reactor power system development

  16. Preliminary nuclear safety assessment of the NEPST (Topaz II) space reactor program

    The United States (US) Strategic Defense Initiative Organization (SDIO) decided to investigate the possibility of launching a Russian Topaz II space nuclear power system. A preliminary nuclear safety assessment was conducted to determine whether or not a space mission could be conducted safely and within budget constraints. As part of this assessment, a safety policy and safety functional requirements were developed to guide both the safety assessment and future Topaz II activities. A review of the Russian flight safety program was conducted and documented. Our preliminary nuclear safety assessment included a number of deterministic analyses, such as; neutronic analysis of normal and accident configurations, an evaluation of temperature coefficients of reactivity, a reentry and disposal analysis, an analysis of postulated launch abort impact accidents, and an analysis of postulated propellant fire and explosion accidents. Based on the assessment to date, it appears that it will be possible to safely launch the Topaz II system in the US with a modification to preclude water flooded criticality. A full scale safety program is now underway

  17. Lightweight Damage Tolerant Radiators for In-Space Nuclear Electric Power and Propulsion

    Craven, Paul; SanSoucie, Michael P.; Tomboulian, Briana; Rogers, Jan; Hyers, Robert

    2014-01-01

    Nuclear electric propulsion (NEP) is a promising option for high-speed in-space travel due to the high energy density of nuclear power sources and efficient electric thrusters. Advanced power conversion technologies for converting thermal energy from the reactor to electrical energy at high operating temperatures would benefit from lightweight, high temperature radiator materials. Radiator performance dictates power output for nuclear electric propulsion systems. Pitch-based carbon fiber materials have the potential to offer significant improvements in operating temperature and mass. An effort at the NASA Marshall Space Flight Center to show that woven high thermal conductivity carbon fiber mats can be used to replace standard metal and composite radiator fins to dissipate waste heat from NEP systems is ongoing. The goals of this effort are to demonstrate a proof of concept, to show that a significant improvement of specific power (power/mass) can be achieved, and to develop a thermal model with predictive capabilities. A description of this effort is presented.

  18. Effects of Nuclear Cross Sections at Different Energies on Space Radiation Exposure from Galactic Cosmic Rays

    Li, Zi-Wei; Adams, James H., Jr.

    2007-01-01

    Space radiation from galactic cosmic rays (GCR) is a major hazard to space crews, especially in long duration human space explorations. For this reason, they will be protected by radiation shielding that fragments the GCR heavy ions. Here we investigate how sensitive the crew's radiation exposure is to nuclear fragmentation cross sections at different energies. We find that in deep space cross sections between about 0.2 and 1.2 GeV/u have the strongest effect on dose equivalent behind shielding in solar minimum GCR environments, and cross sections between about 0.6 and 1.7 GeV/u are the most important at solar maximum'. On the other hand, at the location of the International Space Station, cross sections at_higher -energies, between about 0.6 and 1.7 GeV /u at solar minimum and between about 1.7 and 3.4 GeV/u'at,solar maximum, are the most important This is. due-to the average geomagnetic cutoff for the ISS orbit. We also show the effect of uncertainties in the fragmentation cross sections on the elemental energy spectra behind shielding. These results help to focus the studies of fragmentation cross sections on the proper energy range in order to improve our predictions of crew exposures.

  19. Space Molten Salt Reactor Concept for Nuclear Electric Propulsion and Surface Power

    Eades, M.; Flanders, J.; McMurray, N.; Denning, R.; Sun, X.; Windl, W.; Blue, T.

    Students at The Ohio State University working under the NASA Steckler Grant sought to investigate how molten salt reactors with fissile material dissolved in a liquid fuel medium can be applied to space applications. Molten salt reactors of this kind, built for non-space applications, have demonstrated high power densities, high temperature operation without pressurization, high fuel burn up and other characteristics that are ideal for space fission systems. However, little research has been published on the application of molten salt reactor technology to space fission systems. This paper presents a conceptual design of the Space Molten Salt Reactor (SMSR), which utilizes molten salt reactor technology for Nuclear Electric Propulsion (NEP) and surface power at the 100 kWe to 15 MWe level. Central to the SMSR design is a liquid mixture of LiF, BeF2 and highly enriched U235F4 that acts as both fuel and core coolant. In brief, some of the positive characteristics of the SMSR are compact size, simplified core design, high fuel burn up percentages, proliferation resistant features, passive safety mechanisms, a considerable body of previous research, and the possibility for flexible mission architecture.

  20. The TERRA project, a space nuclear micro-reactor case study

    The TEcnologia de Reatores Rapidos Avancados project, also known as TERRA Project is been conducted by the Institute for Advanced Studies IEAv. The TERRA project has a general objective of understanding and developing the key technologies that will allow (Brazil) the use of nuclear technology to generate electricity in space. This electricity may power several space systems and/or a type of plasma based engine. Also, the type of reactor intended for space may be used for power generation in very inhospitable environment such as the ocean floor. Some of the mentioned technologies may include: Brayton cycles, Stirling engines, heat pipes and its coupled systems, nuclear fuel technology, new materials and several others. Once there is no mission into which apply this technology, at this moment, this research may be conducted in many forms and ways. The fact remains that when this technology becomes needed there will be no way that we (Brazilians) will be able to buy it from. This technology, in this sense, is highly strategic and will be the key to commercially explore deep space. Therefore, there is the need to face the development problems and solve them, to gain experience with our own rights and wrongs. This paper will give a brief overview of what has been done so far, on experimental facilities and hardware that could support space system development, including a Brayton cycle test facility, Tesla turbine testing, and Stirling engine development and modeling. Our great problem today is lack of human resources. To attend that problem we are starting a new graduate program that will allow overcoming that, given the proper time frame. (author)

  1. J. Preston Layton 1919-1992: A guiding light in nuclear space power and propulsion

    Brill, Yvonne C.

    An eventful, highly productive career ended with the death of James Preston ("Pres") Layton in December 1992. His career in rockets, which spanned 50 years, is a chronology of developments in the U.S. space program. Layton was instrumental in the development of rocket technologies ranging from the first jet-assisted take off (JATO) boosters used on aircraft to space nuclear power and propulsion. His work on JATOs, during World War II, involved both testing of solid-fueled units on naval aircraft in the Pacific and developing advanced liquid-fueled systems at the U.S. Naval Academy's laboratory under the direction of Robert H. Goddard, the father of American rocketry. It was Goddard who inspired Layton to devote his life to rocketry. In 1948, as chief of propulsion for the Glenn L. Martin company, he became crew chief in charge of testing the first big U.S. rocket, the Viking series. Layton subsequently joined the research faculty at Princeton University where he served from 1951 to 1976, taking a brief leave in 1955 to earn a Masters Degree at Purdue University under the direction of Maurice Zucrow, another American rocket pioneer. As Chief Engineer of Princeton's Guggenheim Jet Propulsion Center, he created the nation's foremost university rocket research facilities, where he conducted the first experimental evaluation of liquid ozone as a rocket propellant. Later Layton led Princeton's Advanced Systems and Mission Analysis Laboratory, which conducted pioneering studies of space nuclear power and propulsion systems. During this period, at the Lawrence Livermore National Laboratory (on leave from Princeton), Layton helped develop and test the world's first and only nuclear ram-rocket. During his career, Layton performed many responsible consulting tasks for industry and government in the U.S.A. and abroad. He was chief technical consultant to Mathematica, Inc., whose analyses formed the basis for the current Space Shuttle design. He conducted an AIAA assessment of

  2. Mission needs and system commonality for space nuclear power and propulsion

    Nuclear power enables or significantly enhances a variety of space missions whether near-Earth, or for solar system exploration, lunar-Mars exploration and recovery of near-Earth resources. Performance optimizations for individual missions leads to a large number of power and propulsion systems to be developed. However, the realities of the budget and schedules indicates that the number of nuclear systems that will be developed are limited. One needs to seek the ''minimum requirements'' to do a job rather than the last ounce of performance, and areas of commonality. To develop a minimum number of systems to meet the overall DoD, NASA, and commercial needs, the broad spectrum of requirements has been examined along with cost drivers

  3. Thermoemission reactor-converters for nuclear power units in outer space

    In a thermoemission reactor-converter, the direct conversion of thermal into electrical energy is based on the thermoelectric emission of electrons in electricity-generating channels. The paper describes the following: the electricity-generating channel, characteristics of the electricity-generating channels and the reactor-converter, a thermal neutron reactor-converter, a fast neutron reactor-converter, and estimating the mass-limit characteristics of the thermoemission units. Thermoemission nuclear power units with built-in generators in the nuclear reactor core can be regarded as a promising source of electric power for supplying the needs of space equipment for various purposes with a wide range of electric power demands over a long service life and with acceptable mass-limit characteristics

  4. A spherical torus nuclear fusion reactor space propulsion vehicle concept for fast interplanetary travel

    Williams, Craig H.; Borowski, Stanley K.; Dudzinski, Leonard A.; Juhasz, Albert J.

    1999-01-01

    A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Initial requirements were for a human mission to Saturn with a>5% payload mass fraction and a one way trip time of less than one year. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 235 days, with an initial mass in low Earth orbit of 2,941 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including payload, central truss, nuclear reactor (including diverter and fuel injector), power conversion (including turbine, compressor, alternator, radiator, recuperator, and conditioning), magnetic nozzle, neutral beam injector, tankage, start/re-start reactor and battery, refrigeration, communications, reaction control, and in-space operations. Detailed assessment was done on reactor operations, including plasma characteristics, power balance, and component design.

  5. Fabrication of Cerium Oxide and Uranium Oxide Microspheres for Space Nuclear Power Applications

    Jeffrey A. Katalenich; Michael R. Hartman; Robert C. O' Brien

    2013-02-01

    Cerium oxide and uranium oxide microspheres are being produced via an internal gelation sol-gel method to investigate alternative fabrication routes for space nuclear fuels. Depleted uranium and non-radioactive cerium are being utilized as surrogates for plutonium-238 (Pu-238) used in radioisotope thermoelectric generators and for enriched uranium required by nuclear thermal rockets. While current methods used to produce Pu-238 fuels at Los Alamos National Laboratory (LANL) involve the generation of fine powders that pose a respiratory hazard and have a propensity to contaminate glove boxes, the sol-gel route allows for the generation of oxide microsphere fuels through an aqueous route. The sol-gel method does not generate fine powders and may require fewer processing steps than the LANL method with less operator handling. High-quality cerium dioxide microspheres have been fabricated in the desired size range and equipment is being prepared to establish a uranium dioxide microsphere production capability.

  6. Study of nuclear pairing with Configuration-Space Monte-Carlo approach

    Lingle, Mark

    2015-01-01

    Pairing correlations in nuclei play a decisive role in determining nuclear drip-lines, binding energies, and many collective properties. In this work a new Configuration-Space Monte-Carlo (CSMC) method for treating nuclear pairing correlations is developed, implemented, and demonstrated. In CSMC the Hamiltonian matrix is stochastically generated in Krylov subspace, resulting in the Monte-Carlo version of Lanczos-like diagonalization. The advantages of this approach over other techniques are discussed; the absence of the fermionic sign problem, probabilistic interpretation of quantum-mechanical amplitudes, and ability to handle truly large-scale problems with defined precision and error control, are noteworthy merits of CSMC. The features of our CSMC approach are shown using models and realistic examples. Special attention is given to difficult limits: situations with non-constant pairing strengths, cases with nearly degenerate excited states, limits when pairing correlations in finite systems are weak, and pr...

  7. Nuclear structure theory in spin- and number-conserving quasiparticle configuration spaces: General formalism

    Schmid, K.W.; Gruemmer, F.; Faessler, A.

    1984-01-01

    In the present paper a general survey of the mathematical formalism for microscopic nuclear structure calculations in configuration spaces consisting of arbitrary spin- and number-projected Hartree-Fock-Bogoliubov--type quasiparticle determinants is given. On the basis of this formalism, various levels of approximation are then discussed. These lead to a number of microscopic nuclear structure models in between the standard Hartree-Fock-Bogoliubov theory and the complete diagonalization of a given effective many nucleon Hamiltonian. For all these models variational equations are derived and possibilities for their numerical application are estimated. The second part of the present series of two papers will then present initial results of the applications of the simplest of these models to several nuclei in various mass regions.

  8. A Spherical Torus Nuclear Fusion Reactor Space Propulsion Vehicle Concept for Fast Interplanetary Travel

    Williams, Craig H.; Borowski, Stanley K.; Dudzinski, Leonard A.; Juhasz, Albert J.

    1998-01-01

    A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Initial requirements were for a human mission to Saturn with a greater than 5% payload mass fraction and a one way trip time of less than one year. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 235 days, with an initial mass in low Earth orbit of 2,941 mt. Engineering conceptual design, analysis, and assessment was performed on all ma or systems including payload, central truss, nuclear reactor (including divertor and fuel injector), power conversion (including turbine, compressor, alternator, radiator, recuperator, and conditioning), magnetic nozzle, neutral beam injector, tankage, start/re-start reactor and battery, refrigeration, communications, reaction control, and in-space operations. Detailed assessment was done on reactor operations, including plasma characteristics, power balance, power utilization, and component design.

  9. Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Space exploration is a realistic and profitable goal for long-term humanity survival, although the harsh space environment imposes lots of severe challenges to space pioneers. To date, almost all space programs have relied upon Chemical Rockets (CRs) rating superior thrust level to transit from the Earth's surface to its orbit. However, CRs inherently have insurmountable barrier to carry out deep space missions beyond Earth's orbit due to its low propellant efficiency, and ensuing enormous propellant requirement and launch costs. Meanwhile, nuclear rockets typically offer at least two times the propellant efficiency of a CR and thus notably reduce the propellant demand. Particularly, a Nuclear Thermal Rocket (NTR) is a leading candidate for near-term manned missions to Mars and beyond because it satisfies a relatively high thrust as well as a high efficiency. The superior efficiency of NTRs is due to both high energy density of nuclear fuel and the low molecular weight propellant of Hydrogen (H{sub 2}) over the chemical reaction by-products. A NTR uses thermal energy released from a nuclear fission reactor to heat the H{sub 2} propellant and then exhausted the highly heated propellant through a propelling nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub s}p) which represents the ratio of the thrust over the propellant consumption rate. If the average exhaust H{sub 2} temperature of a NTR is around 3,000 K, the I{sub s}p can be achieved as high as 1,000 s as compared with only 450 - 500 s of the best CRs. For this reason, NTRs are favored for various space applications such as orbital tugs, lunar transports, and manned missions to Mars and beyond. The best known NTR development effort was conducted from 1955 to1974 under the ROVER and NERVA programs in the USA. These programs had successfully designed and tested many different reactors and engines. After these projects, the researches on NERVA derived

  10. Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

    Space exploration is a realistic and profitable goal for long-term humanity survival, although the harsh space environment imposes lots of severe challenges to space pioneers. To date, almost all space programs have relied upon Chemical Rockets (CRs) rating superior thrust level to transit from the Earth's surface to its orbit. However, CRs inherently have insurmountable barrier to carry out deep space missions beyond Earth's orbit due to its low propellant efficiency, and ensuing enormous propellant requirement and launch costs. Meanwhile, nuclear rockets typically offer at least two times the propellant efficiency of a CR and thus notably reduce the propellant demand. Particularly, a Nuclear Thermal Rocket (NTR) is a leading candidate for near-term manned missions to Mars and beyond because it satisfies a relatively high thrust as well as a high efficiency. The superior efficiency of NTRs is due to both high energy density of nuclear fuel and the low molecular weight propellant of Hydrogen (H2) over the chemical reaction by-products. A NTR uses thermal energy released from a nuclear fission reactor to heat the H2 propellant and then exhausted the highly heated propellant through a propelling nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (Isp) which represents the ratio of the thrust over the propellant consumption rate. If the average exhaust H2 temperature of a NTR is around 3,000 K, the Isp can be achieved as high as 1,000 s as compared with only 450 - 500 s of the best CRs. For this reason, NTRs are favored for various space applications such as orbital tugs, lunar transports, and manned missions to Mars and beyond. The best known NTR development effort was conducted from 1955 to1974 under the ROVER and NERVA programs in the USA. These programs had successfully designed and tested many different reactors and engines. After these projects, the researches on NERVA derived NTR engines have continued as

  11. Risk knowledge and risk attitudes regarding nuclear energy sources in space

    A series of four studies examined the relationship between how much people know about the risks of using nuclear energy sources in space and how they feel about the technology. The authors found that the more people know, the more favorable they are -- except for two groups of people selected from organizations with strong pro-industry or pro-environment positions. These results suggest that a technology will get a more favorable hearing if it can get its message out -- providing that it has a legitimate story to tell and that the situation has not become too polarized already. The limits to these conclusions are discussed. 19 refs., 3 figs., 1 tab

  12. The Nuclear Structure of 3C84 with Space VLBI (RadioAstron) Observations

    Giovannini, Gabriele; Savolainen, Tuomas; Nagai, Hiroshi; Giroletti, Marcello; Hada, Kazuhiro; Bruni, Gabriele; Hodgson, Jeffrey; Honma, Mareki; Kino, Motoki; Kovalev, Yuri Y; Krichbaum, Thomas; Lee, Sang-Sung; Lobanov, Andrei; Sohn, Bong Won; Sokolovsky, Kirill; Voitsik, Peter; Zensus, J Anton

    2015-01-01

    The radio galaxy 3C84 is a representative of gamma-ray-bright misaligned active galactic nuclei (AGN) and one of the best laboratories to study the radio properties of subparsec scale jets. We discuss here the past and present activity of the nuclear region within the central 1pc and the properties of subparsec-sized components C1, C2 and C3. We compare these results with the high resolution space-VLBI image at 5GHz obtained with the RadioAstron satellite and we shortly discuss the possible correlation of radio emission with the gamma-ray emission.

  13. Nuclear geophysics in space and atmospheric research at INPE/BRAZIl

    Nordemann, D. J. R.; Pereira, E. B.; Marinho, E. V. A.; Sircillineto, F.

    1986-05-01

    In recent years, INPE's research in Nuclear Geophysics has developed in fields of interest to the Institute, the scientific community and the society in general. In the space research field a contribution has been made to the history of meteorite falls on our planet and its possible collision with large meteorites, which may have been the cause of important effects such as biological extinction and extraterrestrial matter gathering. In atmospheric research, spatial and temporal variations of radon measurements in the lower atmosphere permit correlations from micrometeorology to mesoscale phenomena, related to the dynamics of air masses.

  14. Quality assurance program requirements for Space and Terrestrial Nuclear Power Systems

    1982-10-01

    This publication gives the general requirements for planning, managing, and evaluating quality assurance (QA) programs for Space and Terrestrial Nuclear Power Systems. These requirements are based on proven practices and provide direction to project management to aid in safe, reliable, and economical operation. The program's objective is to assure that systems, components, piece parts and materials (including those used for facilities and testing) are designed, developed, fabricated, installed, operated, and maintained in compliance with established engineering criteria. It is the intent of the Department of Energy (DOE) that QA standards be applied to hardware design and development programs from their inception to their completion.

  15. Carbon-Carbon Recuperators in Closed-Brayton-Cycle Nuclear Space Power Systems: A Feasibility Assessment

    Barrett, Michael J.; Johnson, Paul K.

    2004-01-01

    The feasibility of using carbon-carbon recuperators in closed-Brayton-cycle (CBC) nuclear space power conversion systems (PCS) was assessed. Recuperator performance expectations were forecast based on projected thermodynamic cycle state values for a planetary mission. Resulting thermal performance, mass and volume for a plate-fin carbon-carbon recuperator were estimated and quantitatively compared with values for a conventional offset-strip-fin metallic design. Material compatibility issues regarding carbon-carbon surfaces exposed to the working fluid in the CBC PCS were also discussed.

  16. Conceptual design of a multicell thermionic fuel element for a 40-KWE space nuclear power system

    This paper addresses the conceptual design of a Russian thermionic fuel element (TFE) in support of the S-PRIME 40 kWe in-core thermionic space power reactor studies sponsored by the U.S. Department of Energy TI-SNPS program. The design responds to requirements specified by the U.S. component of the S-PRIME team and is based on the multicell ''flashlight'' TFE approach. Following a general description of the TFE design, the considerations leading to several key design decisions are discussed. These include nuclear and thermionic performance, cesium management, fission product management, materials selection, fuel system, and lifetime. copyright American Institute of Physics 1995

  17. Nuclear geophysics in space and atmospheric reserch at INPE/BRAZIl

    During the last years, INPE's research in Nuclear Geophysics has developed in fields of interest to the Institute, the scientific community and the society in general. In the space research field it may be considered as a contribution to the history of meteorite falls in our planet or possible collision with big meteorites which may have been the cause of important effects such as biological extinction and extraterrestrial matter gathering. In the atmospheric research field, spatial and temporal variations of radon measurements in the lower atmosphere allow correlations from micrometeorology to worlwide scale through mesoscale, in the interpretation of phenomena which deal with the dynamics of air masses. (Author)

  18. Fabrication of carbon-carbon heat pipes for space nuclear power applications

    This paper reports that significant advancements have been made in the development of lightweight, high performance, carbon-carbon heat pipes for space nuclear power applications. The subject program has progressed through the concept definition and feasibility analysis stages to the current test article component fabrication and assembly phase. This concept utilizes a carbon-carbon tube with integrally woven fins as the primary structural element and radiative surface, Nb-1Zr liners to contain a potassium working fluid, and welded end caps and fill tubes. Various tests have been performed in the development of suitable liner bonding techniques and in the assessment of material stability

  19. Design of particle bed reactors for the space nuclear thermal propulsion program

    Ludewig, H.; Powell, J.R.; Todosow, M.; Maise, G.; Barletta, R.; Schweitzer, D.G. [Brookhaven National Lab., Upton, NY (United States)

    1996-02-01

    This paper describes the design for the Particle Bed Reactor (PBR) that was considered for the Space Nuclear Thermal Propulsion (SNTP) Program. The methods of analysis and their validation are outlined first. Monte Carlo methods were used for the physics analysis, several new algorithms were developed for the fluid dynamics, heat transfer and transient analysis; and commercial codes were used for the stress analysis. We carried out a critical experiment, prototypic of the PBR to validate the reactor physics; blowdown experiments with beds of prototypic dimensions were undertaken to validate the power-extraction capabilities from particle beds. In addition, materials and mechanical design concepts for the fuel elements were experimentally validated. (author).

  20. Nuclear powered submarines and the Space Station: A comparison of ECLSS requirements

    The NASA Space Station holds remarkable similarity to the modern nuclear powered submarine. Both are required to provide a 90-day mission capability during which all aspects of human habitation must be accommodated. The requirements for environmental control, and failure tolerance of environmental control systems, are also quite similar. Although the resources, operating environments, and mission objectives for the submarine and space station are distinctly different, the problems faced by the environmental control and life support system (ECLSS) engineer require application of the same technologies and design principles. This paper addresses the resources and mission requirements specific to the two vehicles, and discusses their influence on the design of the ECLSS. The design constraints for individual ECLSS subsystems are discussed with the resultant impact on design approach selected for each vehicle

  1. Overview of thermal management issues for advanced military space nuclear reactor power systems

    This paper summarizes the functional and system imposed design constraints and development issues related to military space nuclear power thermal management. The envisioned requirements related to power level, power form and profile, operating duration, and life encompass a wide variety of conceptual future military spacecraft missions. ''Baseload,'' near-constant power output, and ''burstload,'' high peak to average power profile requirements introduce a wide spectrum of potential space reactor configuration needs with a corresponding range of steady state and transient, periodic thermal management technological needs. Spacecraft system operational conditions and design constraints (allowable power/payload mass and volume fractions, survivability and endurability, autonomy, integrability, and orbital operations considerations) impose additional thermal management technological needs. Candidate thermal management technologies are described in terms of their attributes and state of development

  2. Finite-thrust optimization of interplanetary transfers of space vehicle with bimodal nuclear thermal propulsion

    Kharytonov, Oleksii M.; Kiforenko, Boris M.

    2011-08-01

    The nuclear thermal rocket (NTR) propulsion is one of the leading promising technologies for primary space propulsion for manned exploration of the solar system due to its high specific impulse capability and sufficiently high thrust-to-weight ratio. Another benefit of NTR is its possible bimodal design, when nuclear reactor is used for generation of a jet thrust in a high-thrust mode and (with an appropriate power conversion system) as a source of electric power to supply the payload and the electric engines in a low-thrust mode. The model of the NTR thrust control was developed considering high-thrust NTR as a propulsion system of limited power and exhaust velocity. For the proposed model the control of the thrust value is accomplished by the regulation of reactor thermal power and propellant mass flow rate. The problem of joint optimization of the combination of high- and low-thrust arcs and the parameters of bimodal NTR (BNTR) propulsion system is considered for the interplanetary transfers. The interplanetary trajectory of the space vehicle is formed by the high-thrust NTR burns, which define planet-centric maneuvers and by the low-thrust heliocentric arcs where the nuclear electric propulsion (NEP) is used. The high-thrust arcs are analyzed using finite-thrust approach. The motion of the corresponding dynamical system is realized in three phase spaces concerning the departure planet-centric maneuver by means of high-thrust NTR propulsion, the low-thrust NEP heliocentric maneuver and the approach high-thrust NTR planet-centric maneuver. The phase coordinates are related at the time instants of the change of the phase spaces due to the relations between the space vehicle masses. The optimal control analysis is performed using Pontryagin's maximum principle. The numerical results are analyzed for Earth-Mars "sprint" transfer. The optimal values of the parameters that define the masses of NTR and NEP subsystems have been evaluated. It is shown that the low

  3. Space Nuclear Power and Propulsion - a basic Tool for the manned Exploration of the Solar System

    Humanity has started to explore space more than 40 years ago. Numerous spacecraft have left the Earth in this endeavour, but while unmanned spacecraft were already sent out on missions, where they would eventually reach the outer limits of the Solar System, manned exploration has always been confined to the tiny bubble of the Earth's gravitational well, stretching out at maximum to our closest celestial companion - the Moon - during the era of the Apollo programme in the late 60's and early 70's. When mankind made its giant leap, the exploration of our cosmic neighbour was seen as the initial step for the manned exploration of the whole Solar System. Consequently ambitious research and development programmes were undertaken at that time to enable what seemed to be the next logical steps: the establishment of a permanent settled base on the Moon and the first manned mission to Mars in the 80's. Nuclear space power and propulsion played an important role in these entire future scenarios, hence ambitious development programmes were undertaken to make these technologies available. Unfortunately the 70's-paradigm shift in space policies did not only bring an end to the Apollo programme, but it also brought a complete halt to all of these technology programmes and confined the human presence in space to a tiny bubble including nothing more than the Earth's sphere and a mere shell of a few hundred kilometres of altitude, too small to even include the Moon. Today, after more than three decades, manned exploration of the Solar System has become an issue again and so are missions to Moon and Mars. However, studies and analyses show that all of these future plans are hampered by today's available propulsion systems and by the problematic of solar power generation at distances at and beyond of Mars, a problem, however, that can readily be solved by the utilisation of space nuclear reactors and propulsion systems. This paper intends to provide an overview on the various fission

  4. Gaseous-fuel nuclear reactor research for multimegawatt power in space

    Thom, K.; Schneider, R. T.; Helmick, H. H.

    1977-01-01

    In the gaseous-fuel reactor concept, the fissile material is contained in a moderator-reflector cavity and exists in the form of a flowing gas or plasma separated from the cavity walls by means of fluid mechanical forces. Temperatures in excess of structural limitations are possible for low-specific-mass power and high-specific-impulse propulsion in space. Experiments have been conducted with a canister filled with enriched UF6 inserted into a beryllium-reflected cavity. A theoretically predicted critical mass of 6 kg was measured. The UF6 was also circulated through this cavity, demonstrating stable reactor operation with the fuel in motion. Because the flowing gaseous fuel can be continuously processed, the radioactive waste in this type of reactor can be kept small. Another potential of fissioning gases is the possibility of converting the kinetic energy of fission fragments directly into coherent electromagnetic radiation, the nuclear pumping of lasers. Numerous nuclear laser experiments indicate the possibility of transmitting power in space directly from fission energy. The estimated specific mass of a multimegawatt gaseous-fuel reactor power system is from 1 to 5 kg/kW while the companion laser-power receiver station would be much lower in specific mass.

  5. SUSEE: A Compact, Lightweight Space Nuclear Power System Using Present Water Reactor Technology

    Maise, George; Powell, James; Paniagua, John

    2006-01-01

    The SUSEE space reactor system uses existing nuclear fuels and the standard steam cycle to generate electrical and thermal power for a wide range of in-space and surface applications, including manned bases, sub-surface mobile probes to explore thick ice deposits on Mars and the Jovian moons, and mobile rovers. SUSEE cycle efficiency, thermal to electric, ranges from ~20 to 24%, depending on operating parameters. Rejection of waste heat is by a lightweight condensing radiator that can be launched as a compact rolled-up package and deployed into flat panels when appropriate. The 50 centimeter diameter SUSEE reactor can provide power over the range of 10 kW(e) to 1 MW(e) for a period of 10 years. Higher power outputs are possible using slightly larger reactors. System specific weight (reactor, turbine, generator, piping, and radiator is ~3 kg/kW(e). Two SUSEE reactor options are described, based on the existing Zr/O2 cermet and the UH3/ZrH2 TRIGA nuclear fuels.

  6. Space and time optimization of nuclear reactors by means of the Pontryagin principle

    A numerical method is being presented for solving space dependent optimization problems concerning a functional for one dimensional geometries in the few group diffusion approximation. General dimensional analysis was applied to derive relations for the maximum of a functional and the limiting values of the constraints. Two procedures were given for calculating the anisotropic diffusion coefficients in order to improve the results of the diffusion approximation. In this work two procedures were presented for collapsing the microscopic multigroup cross sections, one general and another specific to the space dependent optimization problems solved by means of the Pontryagin maximum principle. Neutron spectrum optimization is performed to ensure the burnup of Pu239 isotope produced in a thermal nuclear reactor. A procedure is also given for the minimization of finite functional set by means of the Pontryagin maximum principle. A method for determining the characteristics of fission Pseudo products is formulated in one group and multigroup cases. This method is applied in the optimization of the burnup in nuclear reactors with fuel electric cells. A procedure to mjnimze the number of the fuel burnup equations is described. The optimization problems presented and solved in this work point to the efficiency of the maximum principle. Each problem on method presented in the various chapters is accompanied by considerations concerning dual problems and possibilities of further research development. (author)

  7. Effect of grid design on Cs-Ba tacitron operation and its application to space nuclear power systems

    Wernsman, Bernard; El-Genk, Mohamed S.

    1995-01-01

    A study of the modulation capabilities of the Cs-Ba tacitron with different grid designs was made. Results showed the ignition grid potential to be independent of grid design at a modulation frequency, fg, of 1 kHz. At fg =22 kHz, discharge ignition with a 26% transparent grid was harder to achieve than at fg=1 kHz. The grid design greatly affects not only the extinguishing potential, but also the forward voltage drop. Increasing the grid transparency and/or aperture size makes it harder to extinguish the discharge (increases ‖ Vg- ‖), but lowers the forward voltage drop across the tacitron. Increasing fg also increases ‖ Vg- ‖, but lowers the forward voltage drop across the tacitron. Increasing fg also increases ‖ Vg- ‖ and lowers the range of Cs pressure for stable current modulation. For a TOPAZ-II type space nuclear reactor power system (SNPS), the lowest electrical power consumption by Cs-Ba tacitrons inverters, employing 34% transparent, 0.5 mm diameter holed grid and operating at IC=10 A or 20 A and fg=1 kHz, is ˜6.5% of the total system output power. This electrical power consumption includes that of the grid power supply and the power loss in the tacitron during discharge.

  8. Independent Safety Assessment of the TOPAZ-II space nuclear reactor power system (Revised)

    The Independent Safety Assessment described in this study report was performed to assess the safety of the design and launch plans anticipated by the U.S. Department of Defense (DOD) in 1993 for a Russian-built, U.S.-modified, TOPAZ-II space nuclear reactor power system. Its conclusions, and the bases for them, were intended to provide guidance for the U.S. Department of Energy (DOE) management in the event that the DOD requested authorization under section 91b. of the Atomic Energy Act of 1954, as amended, for possession and use (including ground testing and launch) of a nuclear-fueled, modified TOPAZ-II. The scientists and engineers who were engaged to perform this assessment are nationally-known nuclear safety experts in various disciplines. They met with participants in the TOPAZ-II program during the spring and summer of 1993 and produced a report based on their analysis of the proposed TOPAZ-II mission. Their conclusions were confined to the potential impact on public safety and did not include budgetary, reliability, or risk-benefit analyses

  9. The approach to risk analysis in three industries: nuclear power, space systems, and chemical process

    The aerospace, nuclear power, and chemical processing industries are providing much of the incentive for the development and application of advanced risk analysis techniques to engineered systems. Risk analysis must answer three basic questions: What can go wrong? How likely is it? and What are the consequences? The result of such analyses is not only a quantitative answer to the question of 'What is the risk', but, more importantly, a framework for intelligent and visible risk management. Because of the societal importance of the subject industries and the amount of risk analysis activity involved in each, it is interesting to look for commonalities, differences, and, hopefully, a basis for some standardization. Each industry has its strengths: the solid experience base of the chemical industry, the extensive qualification and testing procedures of the space industry, and the integrative and quantitative risk and reliability methodologies developed for the nuclear power industry. In particular, most advances in data handling, systems interaction modeling, and uncertainty analysis have come from the probabilistic risk assessment work in the nuclear safety field. In the final analysis, all three industries would greatly benefit from a more deliberate technology exchange program in the rapidly evolving discipline of quantitative risk analysis. (author)

  10. Space nuclear power systems; Proceedings of the 8th Symposium, Albuquerque, NM, Jan. 6-10, 1991. Pts. 1-3

    El-Genk, Mohamed S.; Hoover, Mark D.

    1991-07-01

    The present conference discusses NASA mission planning for space nuclear power, lunar mission design based on nuclear thermal rockets, inertial-electrostatic confinement fusion for space power, nuclear risk analysis of the Ulysses mission, the role of the interface in refractory metal alloy composites, an advanced thermionic reactor systems design code, and space high power nuclear-pumped lasers. Also discussed are exploration mission enhancements with power-beaming, power requirement estimates for a nuclear-powered manned Mars rover, SP-100 reactor design, safety, and testing, materials compatibility issues for fabric composite radiators, application of the enabler to nuclear electric propulsion, orbit-transfer with TOPAZ-type power sources, the thermoelectric properties of alloys, ruthenium silicide as a promising thermoelectric material, and innovative space-saving device for high-temperature piping systems. The second volume of this conference discusses engine concepts for nuclear electric propulsion, nuclear technologies for human exploration of the solar system, dynamic energy conversion, direct nuclear propulsion, thermionic conversion technology, reactor and power system control, thermal management, thermionic research, effects of radiation on electronics, heat-pipe technology, radioisotope power systems, and nuclear fuels for power reactors. The third volume discusses space power electronics, space nuclear fuels for propulsion reactors, power systems concepts, space power electronics systems, the use of artificial intelligence in space, flight qualifications and testing, microgravity two-phase flow, reactor manufacturing and processing, and space and environmental effects. (For individual items see A93-13752 to A93-13937)

  11. The Role of Nuclear Fragmentation in Particle Therapy and Space Radiation Protection.

    Zeitlin, Cary; La Tessa, Chiara

    2016-01-01

    The transport of the so-called HZE particles (those having high charge, Z, and energy, E) through matter is crucially important both in space radiation protection and in the clinical setting where heavy ions are used for cancer treatment. HZE particles are usually considered those having Z > 1, though sometimes Z > 2 is meant. Transport physics is governed by two types of interactions, electromagnetic (ionization energy loss) and nuclear. Models of transport, such as those used in treatment planning and space mission planning must account for both effects in detail. The theory of electromagnetic interactions is well developed, but nucleus-nucleus collisions are so complex that no fundamental physical theory currently describes them. Instead, interaction models are generally anchored to experimental data, which in some areas are far from complete. The lack of fundamental physics knowledge introduces uncertainties in the calculations of exposures and their associated risks. These uncertainties are greatly compounded by the much larger uncertainties in biological response to HZE particles. In this article, we discuss the role of nucleus-nucleus interactions in heavy charged particle therapy and in deep space, where astronauts will receive a chronic low dose from galactic cosmic rays (GCRs) and potentially higher short-term doses from sporadic, unpredictable solar energetic particles (SEPs). GCRs include HZE particles; SEPs typically do not and we, therefore, exclude them from consideration in this article. Nucleus-nucleus collisions can result in the breakup of heavy ions into lighter ions. In space, this is generally beneficial because dose and dose equivalent are, on the whole, reduced in the process. The GCRs can be considered a radiation field with a significant high-LET component; when they pass through matter, the high-LET component is attenuated, at the cost of a slight increase in the low-LET component. Not only are the standard measures of risk

  12. The Role of Nuclear Fragmentation in Particle Therapy and Space Radiation Protection

    Zeitlin, Cary; La Tessa, Chiara

    2016-01-01

    The transport of the so-called HZE particles (those having high charge, Z, and energy, E) through matter is crucially important both in space radiation protection and in the clinical setting where heavy ions are used for cancer treatment. HZE particles are usually considered those having Z > 1, though sometimes Z > 2 is meant. Transport physics is governed by two types of interactions, electromagnetic (ionization energy loss) and nuclear. Models of transport, such as those used in treatment planning and space mission planning must account for both effects in detail. The theory of electromagnetic interactions is well developed, but nucleus–nucleus collisions are so complex that no fundamental physical theory currently describes them. Instead, interaction models are generally anchored to experimental data, which in some areas are far from complete. The lack of fundamental physics knowledge introduces uncertainties in the calculations of exposures and their associated risks. These uncertainties are greatly compounded by the much larger uncertainties in biological response to HZE particles. In this article, we discuss the role of nucleus–nucleus interactions in heavy charged particle therapy and in deep space, where astronauts will receive a chronic low dose from galactic cosmic rays (GCRs) and potentially higher short-term doses from sporadic, unpredictable solar energetic particles (SEPs). GCRs include HZE particles; SEPs typically do not and we, therefore, exclude them from consideration in this article. Nucleus–nucleus collisions can result in the breakup of heavy ions into lighter ions. In space, this is generally beneficial because dose and dose equivalent are, on the whole, reduced in the process. The GCRs can be considered a radiation field with a significant high-LET component; when they pass through matter, the high-LET component is attenuated, at the cost of a slight increase in the low-LET component. Not only are the standard measures of risk

  13. A design study of reactor core optimization for direct nuclear heat-to-electricity conversion in a space power reactor

    Yoshikawa, Hidekazu; Takahashi, Makoto; Shimoda, Hiroshi; Takeoka, Satoshi [Kyoto Univ. (Japan); Nakagawa, Masayuki; Kugo, Teruhiko

    1998-01-01

    To propose a new design concept of a nuclear reactor used in the space, research has been conducted on the conceptual design of a new nuclear reactor on the basis of the following three main concepts: (1) Thermionic generation by thermionic fuel elements (TFE), (2) reactivity control by rotary reflector, and (3) reactor cooling by liquid metal. The outcomes of the research are: (1) A calculation algorithm was derived for obtaining convergent conditions by repeating nuclear characteristic calculation and thermal flow characteristic calculation for the space nuclear reactor. (2) Use of this algorithm and the parametric study established that a space nuclear reactor using 97% enriched uranium nitride as the fuel and lithium as the coolant and having a core with a radius of about 25 cm, a height of about 50 cm and a generation efficiency of about 7% can probably be operated continuously for at least more than ten years at 100 kW only by reactivity control by rotary reflector. (3) A new CAD/CAE system was developed to assist design work to optimize the core characteristics of the space nuclear reactor comprehensively. It is composed of the integrated design support system VINDS using virtual reality and the distributed system WINDS to collaboratively support design work using Internet. (N.H.)

  14. Space Nuclear Power and Propulsion: Materials Challenges for the 21st Century

    Houts, Mike

    2008-01-01

    The current focus of NASA s space fission effort is Fission Surface Power (FSP). FSP systems could be used to provide power anytime, anywhere on the surface of the Moon or Mars. FSP systems could be used at locations away from the lunar poles or in permanently shaded regions, with no performance penalty. A potential reference 40 kWe option has been devised that is cost-competitive with alternatives while providing more power for less mass. The potential reference system is readily extensible for use on Mars. At Mars the system could be capable of operating through global dust storms and providing year-round power at any Martian latitude. To ensure affordability, the potential near-term, 40 kWe reference concept is designed to use only well established materials and fuels. However, if various materials challenges could be overcome, extremely high performance fission systems could be devised. These include high power, low mass fission surface power systems; in-space systems with high specific power; and high performance nuclear thermal propulsion systems. This tutorial will provide a brief overview of space fission systems and will focus on materials challenges that, if overcome, could help enable advanced exploration and utilization of the solar system.

  15. A nucleus-dependent valence-space approach to nuclear structure

    Stroberg, S R; Hergert, H; Holt, J D; Bogner, S K; Roth, R; Schwenk, A

    2016-01-01

    We present a nucleus-dependent valence-space approach for calculating ground and excited states of nuclei, which generalizes the shell-model in-medium similarity renormalization group to an ensemble reference with fractionally filled orbitals. Because the ensemble is used only as a reference, and not to represent physical states, no symmetry restoration is required. This allows us to capture 3N forces among valence nucleons with a valence-space Hamiltonian specifically targeted to each nucleus of interest. Predicted ground-state energies from carbon through nickel agree with results of other large-space ab initio methods, generally to the 1\\% level. In addition, we show that this new approach is required in order to obtain convergence for nuclei in the upper $p$ and $sd$ shells. Finally, we address the $1^+$/$3^+$ ground-state inversion problem in $^{22}\\text{Na}$ and $^{46}\\text{V}$. This approach extends the reach of ab initio nuclear structure calculations to essentially all light- and medium-mass nuclei.

  16. Heat exchanger optimization of a closed Brayton cycle for nuclear space propulsion

    Ribeiro, Guilherme B.; Guimaraes, Lamartine N.F.; Braz Filho, Francisco A., E-mail: gbribeiro@ieav.cta.br, E-mail: guimarae@ieav.cta.br, E-mail: braz@ieav.cta.br [Instituto de Estudos Avancados (IEAV), Sao Jose dos Campos, SP (Brazil). Divisao de Energia Nuclear

    2015-07-01

    Nuclear power systems turned to space electric propulsion differs strongly from usual ground-based power systems regarding the importance of overall size and weight. For propulsion power systems, weight and efficiency are essential drivers that should be managed during conception phase. Considering that, this paper aims the development of a thermal model of a closed Brayton cycle that applies the thermal conductance of heat exchangers in order to predict the energy conversion performance. The centrifugal-flow turbine and compressor characterization were achieved using algebraic equations from literature data. The binary mixture of He-Xe with molecular weight of 40 g/mole is applied and the impact of heat exchanger optimization in thermodynamic irreversibilities is evaluated in this paper. (author)

  17. Brayton cycle conversion and additional French investigations on space nuclear power systems

    French activities in the field of space nuclear power systems have proceeded in anticipation that spacecraft would require such systems for the provision of 20 kW(e) by the year 2005. A liquid metal-cooled reactor patterned on well tested terrestrial technologies has been investigated which employs a Brayton-cycle heat-conversion system in such a way as to allow temperature conditioning of the moderator for a thermal-spectrum reactor. A high pressure gas cycle derivation technique makes it possible to maintain water within the requisite temperature range. The concept thus evolved is attractive in light of fuel inventory, mass, radiation shielding, and control points considerations. 7 refs

  18. Heat exchanger optimization of a closed Brayton cycle for nuclear space propulsion

    Nuclear power systems turned to space electric propulsion differs strongly from usual ground-based power systems regarding the importance of overall size and weight. For propulsion power systems, weight and efficiency are essential drivers that should be managed during conception phase. Considering that, this paper aims the development of a thermal model of a closed Brayton cycle that applies the thermal conductance of heat exchangers in order to predict the energy conversion performance. The centrifugal-flow turbine and compressor characterization were achieved using algebraic equations from literature data. The binary mixture of He-Xe with molecular weight of 40 g/mole is applied and the impact of heat exchanger optimization in thermodynamic irreversibilities is evaluated in this paper. (author)

  19. SP-100 space nuclear power technology requirements for kilowatt-to-megawatt systems

    The SP-100 Space Reactor Power System (SRPS) is being developed by General Electric under contract to the US Department of Energy (DOE) to provide electric power in the range of tens to hundreds of kilowatts. The system represents an enabling technology for a wide variety of earth orbital and interplanetary science missions, nuclear electric propulsion (NEP) stages, and lunar/Mars surface power for the Space Exploration Initiative. An effective infrastructure of industry, national laboratories, and government agencies has made substantial progress in developing SP-100 technology. Hardware development and testing has progressed to the point where all key technical feasibility issues have been resolved. The technology and design are now at a state of readiness to support the definition of early flight demonstration missions in the 1997-2000 time frame. The technology to achieve higher power, long-life missions is under development and is expected to be available in 1998. The benefit of utilizing a low-power [6- to 20-kW(electric) range] early flight mission as a precursor to operational missions near 100 kw(electric) has received renewed interest among government agencies and industry. The status of the nuclear technology has matured to the level of supporting a flight design with the currently available data base. The conductively coupled thermoelectric cell technology is now in the cell-level testing and verification phase with component level readiness to be complete by the end of GFY94. Power system designs using current flight-proven radioisotope thermoelectric generator (RTG) unicouples have been established and also represent an attractive option for early launches

  20. Momentum-space approach to nuclear reaction studies: opportunities and perspectives

    The application of momentum-space three- and four-body scattering equations to the description of nuclear reactions involving systems of three and four nucleons is reviewed, and major achievements and challenges are identified. The calculations include realistic state-of-the-art interactions between nucleon pairs, together with the Coulomb interaction between protons. The effect of including three- and four-nucleon forces is discussed. Further calculations are shown involving the study of nuclear reactions where three-body degrees of freedom play a significant role. These studies involve not just an attempt to describe data in terms of a full three-body model that is solved numerically in a converged way, but also to use this exact framework to validade and test the accuracy of approximate reaction methods such as continuum discretized coupled channel (CDCC), distorted wave impulse approximation (DWIA), plane-wave impulse approximation (PWIA) and the Glauber multiple scattering approach. These comparisons are able to teach researchers under which conditions approximate methods can be used to extract important structural information about exotic nuclei. Prospects and challenges are discussed. (paper)

  1. Nuclear energy gradients for internally contracted complete active space second-order perturbation theory: Multistate extensions

    Vlaisavljevich, Bess

    2016-01-01

    We report the development of the theory and computer program for analytical nuclear energy gradients for (extended) multi-state complete active space perturbation theory (CASPT2) with full internal contraction. The vertical shifts are also considered in this work. This is an extension of the fully internally contracted CASPT2 nuclear gradient program, recently developed for a state-specific variant by us [MacLeod and Shiozaki, J. Chem. Phys. 142, 051103 (2015)]; in this extension, the so-called {\\lambda} equation is solved to account for the variation of the multi-state CASPT2 energies with respect to the change in the amplitudes obtained in the preceding state-specific CASPT2 calculations, and the Z-vector equations are modified accordingly. The program is parallelized using the MPI3 remote memory access protocol that allows us to perform efficient one-sided communication. The optimized geometries of the ground and excited states of a copper corrole and benzophenone are presented as numerical examples. The c...

  2. Marshall Space Flight Center and the Reactor-in-Flight Stage: A Look Back at Using Nuclear Propulsion to Power Space Vehicles in the 1960's

    Wright, Mike

    2003-01-01

    This paper examines the Marshall Space Flight Center s role in the Reactor-In-Flight (RIlT) project that NASA was involved with in the early 1960 s. The paper outlines the project s relation to the joint NASA-Atomic Energy Commission nuclear initiative known as Project Rover. It describes the justification for the RIFT project, its scope, and the difficulties that were encountered during the project. It also provides as assessment of NASA s overall capabilities related to nuclear propulsion in the early 1960 s.

  3. An overview of the Nuclear Electric Propulsion Space Test Program (NEPSTP) satellite

    Voss, S.S. [Los Alamos National Lab., NM (United States); Reynolds, E.L. [Applied Physics Laboratory, Laurel, MD (United States)

    1994-06-01

    Early in 1992 the idea of purchasing a Russian designed and fabricated space reactor power system and integrating it with a US designed satellite went from fiction to reality with the purchase of the first two Topaz II reactors by the Strategic Defense Initiative Organization (now the Ballistic Missile Defense Organization (BMDO). The New Mexico Alliance was formed to establish a ground test facility in which to perform nonnuclear systems testing of the Topaz II, and to evaluate the Topaz 11 system for flight testing with respect to safety, performance, and operability. In conjunction, SDIO requested that the Applied Physics Laboratory in Laurel, MD propose a mission and design a satellite in which the Topaz II could be used as the power source. The outcome of these two activities was the design of the Nuclear Electric Propulsion Space Test Program (NEPSTP) satellite which combines a modified Russian Topaz II power system with a US designed satellite to achieve a specified mission. Due to funding reduction within the SDIO, the Topaz II flight program was postponed indefinitely at the end of Fiscal Year 1993. The purpose of this paper is to present an overview of the NEPSTP mission and the satellite design at the time the flight program ended.

  4. Evaluation of High Energy Nuclear Data of Importance for Use in Accelerator and Space Technology

    Lee, Young Ouk

    2005-10-15

    New evaluation were performed for neutron- and proton-induced reactions for energies up to 250 400 MeV on C-12, N-14, O-16, Al-27, Si-28, Ca-40, Ar-40, Fe-54,58, Ni-64, Cu-63,65, Zr-90, Pb-208, Th-232, U-233,234,236, and Cm-243246. The evaluated results are then applied to the accelerator and space technology. A set of optical model parameters were optimized by searching a number of adjustable coefficients with the Simulated Annealing(SA) method for the spherical nuclei. A parameterization of the empirical formula was proposed to describe the proton-nucleus non-elastic cross sections of high-priority elements for space shielding purpose for proton energies from reaction threshold up to 400 MeV, which was then implemented into the fast scoping space shielding code CHARGE, based on the results of the optical model analysis utilizing up-to-date measurements. For proton energies up to 400 MeV covering most of the incident spectrum for trapped protons and solar energetic particle events, energy-angle spectra of secondary neutrons produced from the proton-induced neutron production reaction were prepared. The evaluated cross section set was applied to the thick target yield (TTY) and promp radiation benchmarks for the accelerator shielding. As for the assessment of the radiological impact of the accelerator to the environment, relevant nuclear reaction cross sections for the activation of the air were recommended among the author's evaluations and existing library based on the available measurements.

  5. Evaluation of High Energy Nuclear Data of Importance for Use in Accelerator and Space Technology

    New evaluation were performed for neutron- and proton-induced reactions for energies up to 250 400 MeV on C-12, N-14, O-16, Al-27, Si-28, Ca-40, Ar-40, Fe-54,58, Ni-64, Cu-63,65, Zr-90, Pb-208, Th-232, U-233,234,236, and Cm-243246. The evaluated results are then applied to the accelerator and space technology. A set of optical model parameters were optimized by searching a number of adjustable coefficients with the Simulated Annealing(SA) method for the spherical nuclei. A parameterization of the empirical formula was proposed to describe the proton-nucleus non-elastic cross sections of high-priority elements for space shielding purpose for proton energies from reaction threshold up to 400 MeV, which was then implemented into the fast scoping space shielding code CHARGE, based on the results of the optical model analysis utilizing up-to-date measurements. For proton energies up to 400 MeV covering most of the incident spectrum for trapped protons and solar energetic particle events, energy-angle spectra of secondary neutrons produced from the proton-induced neutron production reaction were prepared. The evaluated cross section set was applied to the thick target yield (TTY) and promp radiation benchmarks for the accelerator shielding. As for the assessment of the radiological impact of the accelerator to the environment, relevant nuclear reaction cross sections for the activation of the air were recommended among the author's evaluations and existing library based on the available measurements

  6. Request for Naval Reactors Comment on Proposed Prometheus Space Flight Nuclear Reactor High Tier Reactor Safety Requirements and for Naval Reactors Approval to Transmit These Requirements to JPL

    D. Kokkinos

    2005-04-28

    The purpose of this letter is to request Naval Reactors comments on the nuclear reactor high tier requirements for the PROMETHEUS space flight reactor design, pre-launch operations, launch, ascent, operation, and disposal, and to request Naval Reactors approval to transmit these requirements to Jet Propulsion Laboratory to ensure consistency between the reactor safety requirements and the spacecraft safety requirements. The proposed PROMETHEUS nuclear reactor high tier safety requirements are consistent with the long standing safety culture of the Naval Reactors Program and its commitment to protecting the health and safety of the public and the environment. In addition, the philosophy on which these requirements are based is consistent with the Nuclear Safety Policy Working Group recommendations on space nuclear propulsion safety (Reference 1), DOE Nuclear Safety Criteria and Specifications for Space Nuclear Reactors (Reference 2), the Nuclear Space Power Safety and Facility Guidelines Study of the Applied Physics Laboratory.

  7. SRTC criticality safety technical review: Nuclear criticality safety evaluation 94-02, uranium solidification facility pencil tank module spacing

    Review of NMP-NCS-94-0087, ''Nuclear Criticality Safety Evaluation 94-02: Uranium Solidification Facility Pencil Tank Module Spacing (U), April 18, 1994,'' was requested of the SRTC Applied Physics Group. The NCSE is a criticality assessment to show that the USF process module spacing, as given in Non-Conformance Report SHM-0045, remains safe for operation. The NCSE under review concludes that the module spacing as given in Non-Conformance Report SHM-0045 remains in a critically safe configuration for all normal and single credible abnormal conditions. After a thorough review of the NCSE, this reviewer agrees with that conclusion

  8. SPACE-R Thermionic Space Nuclear Power System: Design and Technology Demonstration Program. Semiannual technical progress report for period ending March 1993

    1993-05-01

    This Semiannual Technical Progress Report summarizes the technical progress and accomplishments for the Thermionic Space Nuclear Power System (TI-SNPS) Design and Technology Demonstration Program of the Prime Contractor, Space Power Incorporated (SPI), its subcontractors and supporting National Laboratories during the first half of the Government Fiscal Year (GFY) 1993. SPI`s subcontractors and supporting National Laboratories include: Babcock & Wilcox for the reactor core and externals; Space Systems/Loral for the spacecraft integration; Thermocore for the radiator heat pipes and the heat exchanger; INERTEK of CIS for the TFE, core elements and nuclear tests; Argonne National Laboratories for nuclear safety, physics and control verification; and Oak Ridge National laboratories for materials testing. Parametric trade studies are near completion. However, technical input from INERTEK has yet to be provided to determine some of the baseline design configurations. The INERTEK subcontract is expected to be initiated soon. The Point Design task has been initiated. The thermionic fuel element (TFE) is undergoing several design iterations. The reactor core vessel analysis and design has also been started.

  9. 1990 IEEE Annual Conference on Nuclear and Space Radiation Effects, 27th, Reno, NV, July 16-20, 1990, Proceedings

    Fleetwood, Daniel M. (Editor)

    1990-01-01

    Various papers on nuclear and space radiation effects are presented. The general topics addressed include: basic mechanisms of radiation effects, dosimetry and energy-dependent effects, hardness assurance and testing techniques, single-event upset and latchup, isolation technologies, device and integrated circuit effects and hardening, spacecraft charging and electromagnetic effects.

  10. Vulnerability and failure modes of CMOS/SOS or CMOS/SO: technologies in nuclear and space environments

    Nuclear and space environments consist of several fluxes of ionizing particles. Some of them (photons, electrons, protons) lead to progressive degradation of characteristics. Heavy ions ionize active layers along tracks, and involve specific effects. These effects are discussed in the cases of bipolar (TTL-LS, ECL), CMOS on Sapphire and CMOS on Insulator technologies, through different versions of a unique microprocessor 2901

  11. The Role of Nuclear Fragmentation in Particle Therapy and Space Radiation Protection

    Cary eZeitlin

    2016-03-01

    Full Text Available The transport of so-called HZE particles (those having high charge, Z, and energy, E through matter is crucially important both in space radiation protection and in the clinical setting where heavy ions are used for cancer treatment. Transport physics is governed by two types of interactions, electromagnetic (ionization energy loss and nuclear. Models of transport such as those used in treatment planning and space mission planning must account for both effects in detail. The theory of electromagnetic interactions is well developed, but nucleus-nucleus collisions are so complex that no fundamental physical theory currently describes them. Instead, interaction models are generally anchored to experimental data, which in some areas are far from complete. The lack of fundamental physics knowledge introduces uncertainties in the calculations of exposures and their associated risks. These uncertainties are greatly compounded by the much larger uncertainties in biological response to HZE particles. In this article, we discuss the role of nucleus-nucleus interactions in heavy charged particle therapy and in deep space, where astronauts will receive a chronic low dose from Galactic Cosmic Rays (GCRs and potentially higher short-term doses from sporadic, unpredictable Solar Energetic Particles (SEPs. GCRs include HZE particles; SEPs typically do not and we therefore exclude them from consideration in this article. Nucleus-nucleus collisions can result in the breakup of heavy ions into lighter ions. In space, this is generally beneficial because dose and dose equivalent are, on the whole, reduced in the process. The GCRs can be considered a radiation field with a significant high-LET component; when they pass through matter, the high-LET component is attenuated, at the cost of a slight increase in the low-LET component. Not only are the standard measures of risk reduced by fragmentation, but it can be argued that fragmentation also reduces the

  12. Test and Evaluation of Fiber Optic Sensors for High-Radiation Space Nuclear Power Applications

    Fiber optic sensors can be used to measure a number of parameters, including temperature, strain, pressure and flow, for instrumentation and control of space nuclear power systems. In the past, this technology has often been rejected for use in such a high-radiation environment based on early experiments that revealed a number of degradation phenomena, including radiation-induced fiber attenuation, or 'graying', and Fiber Bragg Grating (FBG) fading and wavelength shift. However, this paper reports the results of recent experimental testing that demonstrates readability of fiber optic sensors to extremely high levels of neutron and gamma radiation. Both distributed Fiber Bragg Grating (FBG) sensors and single-point Extrinsic Fabry Perot Interferometer (EFPI) sensors were continuously monitored over a 2-month period, during which they were exposed to combined neutron and gamma radiation in both in-core and ex-core positions within a nuclear reactor. Total exposure reached approximately 2 x 1019 cm-2 fast neutron (E > 1 MeV) fluence and 8.7 x 108 Gy gamma for in-core sensors. FBG sensors were interrogated using a standard Luna Innovations FBG measurement system, which is based on optical frequency-domain reflectometer (OFDR) technology. Approximately 74% of the 19 FBG sensors located at the core centerline in the in-core position exhibited sufficient signal-to-noise ratio (SNR) to remain readable even after receiving the maximum dose. EFPI sensors were spectrally interrogated using a broadband probe source operating in the 830 nm wavelength region. While these single-point sensors failed early in the test, important additional fiber spectral transmission data was collected, which indicates that interrogation of EFPI sensors in alternate wavelength regions may allow significant improvement in sensor longevity for operation in high-radiation environments. This work was funded through a Small Business Innovative Research (SBIR) contract with the Nasa Glenn Research

  13. Use of nuclear space technology of direct energy conversion for terrestrial application

    In due time the SSC RF-IPPE exercised the scientific supervision and directly participated in the development, fabrication, space flight test and maintenance of the direct energy conversion nuclear power plants (NPP) for space application under the 'BUK' and 'TOPAZ' programs. We have used the acquired experience and the high technologies developed for the 'BUK' NPP with a thermoelectric conversion of thermal (nuclear) energy into electrical one in the development under the order of RAO 'GAZPROM' of the natural gas fired self contained thermoelectric current sources (AIT-500) and heat and electricity sources (TEP-500). These are intended for electrochemical rust protection of gas pipelines and for the electricity and heat supply to the telemetric and microwave-link systems located along the gas pipelines. Of special interest at the moment are the new developments of self contained current sources with the electrical output of ∼500 Wel for new gas pipelines being constructed under the projects such as the 'Yamal-Europe' project. The electrochemical rust protection of gas pipelines laying on unsettled and non-electrified territory of arctic regions of Russia is performed by means of the so-called Cathodic Protection Stations (CPS). Accounting for a complex of rather rigid requirements imposed by arctic operating conditions, the most attractive sources of electricity supply to the CPS are the thermoelectric heat-into-electricity converters and the generators (TEG). This paper deals with the essential results of the development, investigation and testing of unconventional TEGs using the low-temperature bismuth-tellurium thermoelectric batteries assembled together as tubular thermoelectric batteries with a radial ring geometry built into the gas-heated thermoelectric modules, which are collected to make up either the thermoelectric plants for heat and electricity supply or the self contained power sources. One of the peculiarities of these plants is the combination of

  14. A concept of radiation safety for nuclear power units in space and its implementation in the 'Kosmos-1900' satellite

    Experience in ensuring radiation safety for nuclear units in outer space has shown the adequacy of using two independent systems: a booster system and a system for dispersing the reactor based on using active means to break up its structure. The theoretical calculations and experimental research performed in the Soviet Union, the engineering and construction development, and testing have confirmed the effectiveness of the booster and reactor dispersion systems as well as their capability to operate with the necessary reliability during normal operating conditions and in accident situations aboard space equipment. The paper discussed nuclear unit composition and radioactivity, systems ensuring radiation safety, accident situations aboard space equipment and the radiation safety system's operating capability, and the Kosmos-1900 satellite

  15. Evolution of systems concepts for a 100 kWe class Space Nuclear Power System

    Katucki, R.; Josloff, A.; Kirpich, A.; Florio, F.

    1985-01-01

    Conceptual designs for the SP-100 Space Nuclear Power System have been prepared that meet baseline, backup and growth program scenarios. Near-term advancement in technology was considered in the design of the Baseline Concept. An improved silicon-germanium thermoelectric technique is used to convert the heat from a fast-spectrum, liquid lithium cooled reactor. This system produces a net power of 100 kWe with a 10-year end of life, under the specific constraints of area and volume. Output of the Backup Concept is estimated to be 60 kWe for a 10-year end of life. This system differs from the Baseline Concept because currently available thermoelectric conversion is used from energy supplied by a liquid sodium cooled reactor. The Growth Concept uses Stirling engine conversion to produce 100 kWe within the constraints of mass and volume. The Growth Concept can be scaled up to produce a 1 MWe output that uses the same type reactor developed for the Baseline Concept. Assessments made for each of the program scenarios indicate the key development efforts needed to initiate detailed design and hardware program phases. Development plans were prepared for each scenario that detail the work elements and show the program activities leading to a state of flight readiness.

  16. The scalability of OTR (out-of-core thermionic reactor) space nuclear power systems

    Gallup, D.R.

    1990-03-01

    In this document, masses of the STAR-C power system and an optimized out-of-core thermionic reactor (OTR) power system versus power level are investigated. The impacts of key system parameters on system performance are also addressed. The STAR-C is mass competitive below about 15 kWe, but at higher power levels the scalability is relatively poor. An optimized OR is the least massive space nuclear power system below 25 kWe, and scales well to 50 kWe. The system parameters that have a significant impact on the scalability of the STAR-C are core thermal flux, thermionic converter efficiency, and core length to diameter ratio. The emissivity of the core surface is shown to be a relatively unimportant parameter. For an optimized OR power system, the most significant system parameter is the maximum allowable fuel temperature. It is also shown that if advanced radiation-hardened electronics are used in the satellite payload, a very large mass savings is realized. 10 refs., 23 figs., 7 tabs.

  17. Energy conversion system optimization study for multimegawatt space nuclear power applications

    The major objective of this paper is to present a detailed description of the energy conversion system analysis and optimization procedures that were part of a broader preliminary study aimed at designing a multimegawatt (MMW) space nuclear power system. In optimizing the energy conversion system it is assumed that the most massive component of the system is the radiator and therefore the subject of optimization is the radiator mass. The closed loop Brayton and the liquid metal Rankine cycles are analyzed for a 165 MWe system. The radiator mass optimized systems based on both cycles are compared for a wide range of operating conditions. In addition, for a 165 MWe power output, the MMW power system mass is calculated using an open loop Brayton cycle. For the desired electric output, results show that the hydrogen cooled/potassium Rankine cycle is the recommended energy conversion system since it is superior to any closed loop Brayton cycle. Additionally, results show that the open loop Brayton cycle system with hydrogen working fluid has mass comparable to the selected Rankine cycle system

  18. Geo-Space observation of atmospheric environmental effects associated with 2011 Fukushima nuclear accident

    Pulinets, Sergey; Ouzounov, Dimitar; Hernandez-Pajares, Manuel; Hattori, Katsumi; Garcia-Rigo, Alberto

    2014-05-01

    Our approach of using multiple geo-space observation is based on the LAIC (Lithosphere- Atmosphere- Ionosphere Coupling) model and the gained experience during similar analysis of Three-Mile Island and Chernobyl accidents. We do collect a unique dataset of geophysical data for the period around the time of the most active phase of Fukushima explosions (from 12 March till 31 March, 71-90 DOY). We analyzed following data sets: (i) ground temperature and relative humidity data from the JMA network of Japan, (ii) satellite meteorological data and assimilative models to obtain the integrated water vapor chemical potential; (iii) the infrared emission on the top of atmosphere measured by NOAA and GEOS satellites estimated as Outgoing Longwave Radiation; and (iv) multiple ionospheric measurements , including ground based ionosondes, GPS vTEC from GEONET network, COSMIC/FORMOSAT constellation occultation data, JASON satellite TEC measurements, and tomography reconstruction technique to obtain 3D distribution of electron concentration around the Fukushima power plant. As a result we were able to detect the anomalies in different geophysical parameters representing the dynamics of the Fukushima nuclear accident development and the effects on the atmospheric environment. Their temporal evolution demonstrates the synergy in different atmospheric anomalies development what implies the existence of the common physical mechanism described by the LAIC model.

  19. Brayton cycle conversion and additional French investigations on space nuclear power systems

    The French studies on space nuclear power systems were relatively active the past six years. It was anticipated that 20-kWe should have to be supplied to a spacecraft as soon as in 2005 and a reference near term liquid metal-cooled reactor using available terrestrial technologies as much as possible was mainly investigated. A Brayton cycle heat conversion has been adopted from the beginning and it remains considered. Because first applications are delayed, more attractive concepts can be contemplated. The basic idea is to take advantage of the Brayton cycle specific properties and for instance to use them for the temperature conditioning of the moderator of a thermal spectrum reactor. At first, the utilization of ZrH was thought mandatory, but recent proposals have prompted to use the conventional, effective light water material for that purpose. A gas cycle high pressure (HP) derivation technique makes it possible to maintain water within an adequate temperature range. A Brayton cycle adaptation and an example of a gas-cooled, particle bed fuel elements, H2O moderated reactor are briefly described. Key comparison data are given. Such concepts should be attractive from fuel inventory, mass, radition shielding and control points of view

  20. Brayton cycle conversion system and temperature conditioning of small space nuclear reactors

    A companion paper (Carre et al. 1989) presented at this symposium gives an overview of the French preliminary studies on space nuclear power systems in progress within the framework of a three-year (1986-1989) program. Other papers (Proust et al. 1988, Tilliette et al. 1988, Tilliette IECEC 1988) supplement the information on this activity. Low power levels of about 20-KWe and both liquid metal- and gas-cooled reactors are concerned. The Brayton cycle is currently selected as the conversion subsystem. Critical issues like safety, reliability, radiation shielding and reactor concept and technology have to be addressed more and more carefully and relevant temperature conditions are crucial. It is shown in this paper that the Brayton cycle can offer a valuable flexibility which allows the desired thermal environment. For instance, it is possible to significantly decrease the reactor inlet temperature and consequently, also given an adequate design, to favourably put forward convenient solutions for the lateral and axial bottom reflector, the shadow shield, the control drums drives and safety rods actuators and penetrations as well as for the possibility of using efficient moderator materials like metal hydrides (ZrH or 7LiH), which is worth being investigated as far as low power levels are concerned. Examples of Brayton cycle conversion subsystems and possible reactor arrangements are presented for both gas-cooled and liquid metal (NaK or Na)-cooled reactor heat sources. The study follows up the research described by Thilliette (1988, IECEC)

  1. Compressor and Turbine Models of Brayton Units for Space Nuclear Power Systems

    Gallo, Bruno M.; El-Genk, Mohamed S.; Tournier, Jean-Michel

    2007-01-01

    Closed Brayton Cycles with centrifugal flow, single-shaft turbo-machines are being considered, with gas cooled nuclear reactors, to provide 10's to 100's of electrical power to support future space exploration missions and Lunar and Mars outposts. Such power system analysis is typically based on the cycle thermodynamics, for given operating pressures and temperatures and assumed polytropic efficiencies of the compressor and turbine of the Brayton energy conversion units. Thus the analysis results not suitable for modeling operation transients such as startup and changes in the electric load. To simulate these transients, accurate models of the turbine and compressor in the Brayton rotating unit, which calculate the changes in the compressor and turbine efficiencies with system operation are needed. This paper presents flow models that account for the design and dimensions of the compressor impeller and diffuser, and the turbine stator and rotor blades. These models calculate the various enthalpy losses and the polytropic efficiencies along with the pressure ratios of the turbine and compressor. The predictions of these models compare well with reported performance data of actual hardware. In addition, the results of a parametric analysis to map the operations of the compressor and turbine, as functions of the rotating shaft speed and inlet Mach number of the gas working fluid, are presented and discussed. The analysis used a binary mixture of He-Xe with a molecular weight of 40 g/mole as the working fluid.

  2. Alkali metal Rankine cycle boiler technology challenges and some potential solutions for space nuclear power and propulsion applications

    Stone, J.R.

    1994-07-01

    Alkali metal boilers are of interest for application to future space Rankine cycle power conversion systems. Significant progress on such boilers was accomplished in the 1960's and early 1970's, but development was not continued to operational systems since NASA's plans for future space missions were drastically curtailed in the early 1970's. In particular, piloted Mars missions were indefinitely deferred. With the announcement of the Space Exploration Initiative (SEI) in July 1989 by President Bush, interest was rekindled in challenging space missions and, consequently in space nuclear power and propulsion. Nuclear electric propulsion (NEP) and nuclear thermal propulsion (NTP) were proposed for interplanetary space vehicles, particularly for Mars missions. The potassium Rankine power conversion cycle became of interest to provide electric power for NEP vehicles and for 'dual-mode' NTP vehicles, where the same reactor could be used directly for propulsion and (with an additional coolant loop) for power. Although the boiler is not a major contributor to system mass, it is of critical importance because of its interaction with the rest of the power conversion system; it can cause problems for other components such as excess liquid droplets entering the turbine, thereby reducing its life, or more critically, it can drive instabilities-some severe enough to cause system failure. Funding for the SEI and its associated technology program from 1990 to 1993 was not sufficient to support significant new work on Rankine cycle boilers for space applications. In Fiscal Year 1994, funding for these challenging missions and technologies has again been curtailed, and planning for the future is very uncertain. The purpose of this paper is to review the technologies developed in the 1960's and 1970's in the light of the recent SEI applications. In this way, future Rankine cycle boiler programs may be conducted most efficiently.

  3. Preliminary Thermo-hydraulic Core Design Analysis of Korea Advanced Nuclear Thermal Engine Rocket for Space Application

    Nam, Seung Hyun; Lee, Jeong Ik; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    Nclear rockets improve the propellant efficiency more than twice compared to CRs and thus significantly reduce the propellant requirement. The superior efficiency of nuclear rockets is due to the combination of the huge energy density and a single low molecular weight propellant utilization. Nuclear Thermal Rockets (NTRs) are particularly suitable for manned missions to Mars because it satisfies a relatively high thrust as well as a high propellant efficiency. NTRs use thermal energy released from a nuclear fission reactor to heat a single low molecular weight propellant, i. e., Hydrogen (H{sub 2}) and then exhausted the extremely heated propellant through a thermodynamic nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub sp}) which represents the ratio of the thrust over the rate of propellant consumption. The difference of I{sub sp} makes over three times propellant savings of NTRs for a manned Mars mission compared to CRs. NTRs can also be configured to operate bimodally by converting the surplus nuclear energy to auxiliary electric power required for the operation of a spacecraft. Moreover, the concept and technology of NTRs are very simple, already proven, and safe. Thus, NTRs can be applied to various space missions such as solar system exploration, International Space Station (ISS) transport support, Near Earth Objects (NEOs) interception, etc. Nuclear propulsion is the most promising and viable option to achieve challenging deep space missions. Particularly, the attractions of a NTR include excellent thrust and propellant efficiency, bimodal capability, proven technology, and safe and reliable performance. The ROK has also begun the research for space nuclear systems as a volunteer of the international space race and a major world nuclear energy country. KANUTER is one of the advanced NTR engines currently under development at KAIST. This bimodal engine is operated in two modes of propulsion with 100 MW

  4. Preliminary Thermo-hydraulic Core Design Analysis of Korea Advanced Nuclear Thermal Engine Rocket for Space Application

    Nclear rockets improve the propellant efficiency more than twice compared to CRs and thus significantly reduce the propellant requirement. The superior efficiency of nuclear rockets is due to the combination of the huge energy density and a single low molecular weight propellant utilization. Nuclear Thermal Rockets (NTRs) are particularly suitable for manned missions to Mars because it satisfies a relatively high thrust as well as a high propellant efficiency. NTRs use thermal energy released from a nuclear fission reactor to heat a single low molecular weight propellant, i. e., Hydrogen (H2) and then exhausted the extremely heated propellant through a thermodynamic nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (Isp) which represents the ratio of the thrust over the rate of propellant consumption. The difference of Isp makes over three times propellant savings of NTRs for a manned Mars mission compared to CRs. NTRs can also be configured to operate bimodally by converting the surplus nuclear energy to auxiliary electric power required for the operation of a spacecraft. Moreover, the concept and technology of NTRs are very simple, already proven, and safe. Thus, NTRs can be applied to various space missions such as solar system exploration, International Space Station (ISS) transport support, Near Earth Objects (NEOs) interception, etc. Nuclear propulsion is the most promising and viable option to achieve challenging deep space missions. Particularly, the attractions of a NTR include excellent thrust and propellant efficiency, bimodal capability, proven technology, and safe and reliable performance. The ROK has also begun the research for space nuclear systems as a volunteer of the international space race and a major world nuclear energy country. KANUTER is one of the advanced NTR engines currently under development at KAIST. This bimodal engine is operated in two modes of propulsion with 100 MWth power and

  5. General-purpose heat source project and space nuclear safety and fuels program. Progress reportt, January 1980

    This formal monthly report covers the studies related to the use of 238PuO2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are the general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed here are of a continuing nature. Results and conclusions described may change as the work continues. Published reference to the results cited in this report should not be made without the explicit permission of the person in charge of the work

  6. Existence of Continuous and C\\`adl\\`ag Versions for Cylindrical Processes in the Dual of a Nuclear Space

    Fonseca-Mora, Christian

    2015-01-01

    Let $\\Phi$ be a nuclear space and let $\\Phi'_{\\beta}$ denote its strong dual. In this paper we introduce sufficient conditions for a cylindrical process in $\\Phi'$ to have a version that is a $\\Phi'_{\\beta}$-valued continuous or c\\'{a}dl\\'{a}g process. We also establish sufficient conditions for the existence of such a version taking values and having finite moments in a Hilbert space continuously embedded in $\\Phi'_{\\beta}$. Finally, we apply our results to the study of properties of cylindr...

  7. Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities

    MM Hall

    2006-01-31

    A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing.

  8. Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities

    A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing

  9. Space nuclear reactor concepts for avoidance of a single point failure

    This paper presents three space nuclear reactor concepts for future exploration missions requiring electrical power of 10's to 100's kW, for 7-10 years. These concepts avoid a single point failure in reactor cooling; and they could be used with a host of energy conversion technologies. The first is lithium or sodium heat pipes cooled reactor. The heat pipes operate at a fraction of their prevailing capillary or sonic limit. Thus, when a number of heat pipes fail, those in the adjacent modules remove their heat load, maintaining reactor core adequately cooled. The second is a reactor with a circulating liquid metal coolant. The reactor core is divided into six identical sectors, each with a separate energy conversion loop. The sectors in the reactor core are neurotically coupled, but hydraulically decoupled. Thus, when a sector experiences a loss of coolant, the fission power generated in it will be removed by the circulating coolant in the adjacent sectors. In this case, however, the reactor fission power would have to decrease to avoid exceeding the design temperature limits in the sector with a failed loop. These two reactor concepts are used with energy conversion technologies, such as advanced Thermoelectric (TE), Free Piston Stirling Engines (FPSE), and Alkali Metal Thermal-to- Electric Conversion (AMTEC). Gas cooled reactors are a better choice to use with Closed Brayton Cycle engines, such as the third reactor concept to be presented in the paper. It has a sectored core that is cooled with a binary mixture of He-Xe (40 gm/mole). Each of the three sectors in the reactor has its own CBC and neutronically, but not hydraulically, coupled to the other sectors

  10. Compositional characterization of Nb-1% Zr alloy used for the reactor vessel in space nuclear power systems by ICPOES

    Mira mist nebulizer of ICP-OES (Inductive Coupled Plasma-Optical Emission Spectrometer) in combination with argon humidifier and Teflon kit was used for quantitative determination of Nb, Zr, traces of Mg and Al in Nb-1%Zr alloy. This alloy is commonly used in space power applications where resistance to liquid alkali metal corrosion at temperatures near 1100 K is the primary concern. In addition to this, Nb-1% Zr alloy is also used in fabrication of various parts of space nuclear power reactor like vessel, heat pipe, and power components. It was observed that the addition of 1% zirconium to niobium greatly improved the creep strength over the soft pure metal. Thus Nb-1%Zr became the replacement for pure niobium in applications requiring the chemical resistance of niobium and a material with high melting temperature. Nb-1%Zr also has low thermal nuclear capture cross-section properties

  11. Journey into tomorrow - Developing nuclear propulsion for the Space Exploration Initiative

    Harer, Kathleen F.; Graham, Scott R.; Bennett, Gary L.

    1992-01-01

    Nuclear propulsion, either nuclear thermal propulsion or nuclear electric propulsion, offers the potential of reduced trip times and/or reduced mass into low earth orbit, compared to chemical propulsion systems. In addition, the greater performance benefits of nuclear propulsion can provide the added margin for greater operational flexibility, including mission abort options and increased launch windows. During the 1950s and 1960s experimental and analytical studies showed the feasibility of nuclear propulsion. NASA, in cooperation with other agencies and organizations, is currently planning a technology development program for nuclear propulsion. The overall objective is to develop at least one NTP concept and one NEP concept for piloted and robotic (e.g., cargo) missions to Mars.

  12. Methods of thermal-to-electric energy conversion in on-board nuclear power plants for space applications

    The present state and prospects for development of space programmes of the USSR and the USA, as well as of a number of countries of Europe and Asia, and of international programmes, provide for a steady rise in the need for on-board energy supply of space objects. The solution of both scientific and technical problems, as well as of the problem of survival on-board the spacecraft, depends to a considerable extent upon such energy supplies. Nuclear sources of heat such as reactors or radioisotopes and energy converters, which feature a number of advantages for autonomous power supply over solar cells and fuel cells, have already been operated, or been designed and developed for use as on-board power sources for the execution of some space programmes. Major difficulties are now presented by the problem of developing converter units for space applications that would be both reliable in operation and economical with regard to their power and weight. The review discusses methods for the conversion of nuclear heat to electricity in spaceborne power systems. For a better understanding of processes occurring in dynamic converters, namely, gas-turbine and vapour-turbine ones, brief consideration is given to their thermodynamic cycles, and, in the case of direct conversion methods such as thermoelectric, thermionic and magnetohydrodynamic ones, to the physical principles underlying such methods. Conversion diagrams are considered, basic characteristics of the existing or projected nuclear power plants for space applications are combined in tables, and an attempt is made to compare these characteristics to determine the place of such power plants in space power engineering. The review is intended for large sections of scientists, engineers and state employees concerned with this problem, and aims at presenting in condensed and general form the current state of the problem. The bibliography has been compiled to cover the major works published during the last five years on the

  13. High-Fidelity Space-Time Adaptive Multiphysics Simulations in Nuclear Engineering

    Solin, Pavel [Univ. of Reno, NV (United States); Ragusa, Jean [Texas A & M Univ., College Station, TX (United States)

    2014-03-09

    We delivered a series of fundamentally new computational technologies that have the potential to significantly advance the state-of-the-art of computer simulations of transient multiphysics nuclear reactor processes. These methods were implemented in the form of a C++ library, and applied to a number of multiphysics coupled problems relevant to nuclear reactor simulations.

  14. High-Fidelity Space-Time Adaptive Multiphysics Simulations in Nuclear Engineering

    We delivered a series of fundamentally new computational technologies that have the potential to significantly advance the state-of-the-art of computer simulations of transient multiphysics nuclear reactor processes. These methods were implemented in the form of a C++ library, and applied to a number of multiphysics coupled problems relevant to nuclear reactor simulations.

  15. Analysis of space systems for the space disposal of nuclear waste follow-on study. Volume 2. Technical report

    None

    1982-01-01

    Some of the conclusions reached as a result of this study are summarized. Waste form parameters for the reference cermet waste form are available only by analogy. Detail design of the waste payload would require determination of actual waste form properties. The billet configuration constraints for the cermet waste form limit the packing efficiency to slightly under 75% net volume. The effect of this packing inefficiency in reducing the net waste form per waste payload can be seen graphically. The cermet waste form mass per unit mass of waste payload is lower than that of the iodine waste form even though the cermet has a higher density (6.5 versus 5.5). This is because the lead iodide is cast achieving almost 100% efficiency in packing. This inefficiency in the packing of the cermet results in a 20% increase in number of flights which increases both cost and risk. Alternative systems for waste mixes requiring low flight rates (technetium-99, iodine-129) can make effective use of the existing 65K space transportation system in either single- or dual-launch scenarios. A comprehensive trade study would be required to select the optimum orbit transfer system for low-launch-rate systems. This study was not conducted as part of the present effort due to selection of the cermet waste form as the reference for the study. Several candidates look attractive for both single- and dual-launch systems (see sec. 4.4), but due to the relatively small number of missions, a comprehensive comparison of life cycle costs including DDT and E would be required to select the best system. The reference system described in sections 5.0, 6.0, 7.0, and 8.0 offers the best combination of cost, risk, and alignment with ongoing NASA technology development efforts for disposal of the reference cermet waste form.

  16. Characterization of specific nuclear reaction channels by deconvolution in the energy space of the total nuclear cross-section of protons - applications to proton therapy and technical problems

    Ulmer, W

    2016-01-01

    The total nuclear cross-section Qtot(E) resulting from the interaction of protons with nuclei is decomposed in 3 different contributions: 1. elastic scatter at the complete nucleus, which adopts a part of the proton kinetic energy; 2. inelastic scatter at a nucleus, which changes its quantum numbers by vibrations, rotations, transition to highly excited states; 3. proper nuclear reactions with change of the mass and/or charge number. Then different particles leave the hit nucleus (neutrons, protons, etc.), which is now referred to as 'heavy recoil' nucleus. The scatter parts of Qtot(E) according to points 1 and 2 can be removed by a deconvolution acting at Qtot(E) in the energy space. The typical nuclear reaction channels are mainly characterized by resonances of a reduced cross-section function Qred(E). The procedure is applied to cross-sections of therapeutic protons and also to Cs55137 as an example with technical relevance (transmutations with the goal to drastically reduce its half-time).

  17. The nuclear structure and related properties of some low-lying isomers of free-space O_n clusters (n=6, 8, 12)

    Forte, G; March, N H; Pucci, R

    2013-01-01

    After some introductory comments relating to antiferromagnetism of crystalline O_2, and brief remarks on the geometry of ozone, Hartree-Fock (HF) theory plus second-order Moller-Plesset (MP2) corrections are used to predict the nuclear structure of low-lying isomers of free-space O_n clusters, for n=6, 8, and 12. The equilibrium nuclear-nuclear potential energy is also discussed in relation to the number n of oxygen atoms in the cluster.

  18. 12th Symposium on Space Nuclear Power and Propulsion. Conference on Alternative Power from Space (APFS),Conference on Accelerator-Driven Transmutation Technologies and Applications (A-DTTA)

    These proceedings represent papers presented at the 12th symposium on Space Nuclear Power and Propulsion held in Albuquerque, New Mexico. The symposium theme was ''commercialization and technology transfer''. The topics discussed include: wireless power transmission, solar power from space next generation spacecraft, space power electronics and power management, flight testing of components, manufacturing and processing of materials, nuclear propulsion, reactors and shielding and many others of interest to the scientific community representing industry, government and academic institutions. There were 163 papers presented at the conference and 60 have been abstracted for the Energy Science and Technology database

  19. 12th Symposium on Space Nuclear Power and Propulsion. Conference on Alternative Power from Space (APFS),Conference on Accelerator-Driven Transmutation Technologies and Applications (A-DTTA)

    Mohamed, S.E. [ed.] [Institute for Space and Nuclear Power Studies, University of New Mexico, Albuquerque, NM (United States)

    1995-12-31

    These proceedings represent papers presented at the 12th symposium on Space Nuclear Power and Propulsion held in Albuquerque, New Mexico. The symposium theme was ``commercialization and technology transfer``. The topics discussed include: wireless power transmission, solar power from space next generation spacecraft, space power electronics and power management, flight testing of components, manufacturing and processing of materials, nuclear propulsion, reactors and shielding and many others of interest to the scientific community representing industry, government and academic institutions. There were 163 papers presented at the conference and 60 have been abstracted for the Energy Science and Technology database. (AIP)

  20. Application of space and aviation technology to improve the safety and reliability of nuclear power plant operations. Final report

    This report investigates various technologies that have been developed and utilized by the aerospace community, particularly the National Aeronautics and Space Administration (NASA) and the aviation industry, that would appear to have some potential for contributing to improved operational safety and reliability at commercial nuclear power plants of the type being built and operated in the United States today. The main initiator for this study, as well as many others, was the accident at the Three Mile Island (TMI) nuclear power plant in March 1979. Transfer and application of technology developed by NASA, as well as other public and private institutions, may well help to decrease the likelihood of similar incidents in the future

  1. Impact of the use of low or medium enriched uranium on the masses of space nuclear reactor power systems

    The design process for determining the mass increase for the substitution of low-enriched uranium (LEU) for high-enriched uranium (HEU) in space nuclear reactor systems is an optimization process which must simultaneously consider several variables. This process becomes more complex whenever the reactor core operates on an in-core thermionic power conversion, in which the fissioning of the nuclear fuel is used to directly heat thermionic emitters, with the subsequent elimination of external power conversion equipment. The increased complexity of the optimization process for this type of system is reflected in the work reported herein, where considerably more information has been developed for the moderated in-core thermionic reactors

  2. Space charge effects on 220-MeV microtron for non-destructive nuclear material detection system

    A nuclear material detection system (NMDS) based on neutron / γ-ray hybrid approach has been proposed for the container inspection at sea ports. While neutron is to be used for a fast pre-screening, quasi-monochromatic γ-ray beam from the laser Compton scattering (LCS) source will be used for an isotope identification on the precise inspection of the cargoes. Nuclear resonance fluorescence method is going to be employed for the isotope identification because of its superiority in high selectivity and in high penetration capability through the shielding objects. In the system a high energy electron beam of good quality is required for LCS. A 220-MeV racetrack microtron (RTM) is one of the most promising candidates as an electron source for such the practical use. Suppose a few nC/bunch of electrons are accelerated, space charge effects (SCEs) on the RTM are investigated using the tracking code Parmela. (author)

  3. Review, Analyses and Recommendations Related to Modern International Use of Nuclear Space Technologies with Focus on United States and Russia

    Smith, T.

    The current Administration under President Barack Obama has given NASA a new directive in manned spaceflight. Instead of building a fleet of Ares rockets with various load specifications to deliver astronauts to the International Space Station (ISS) and return them to the Moon, the 2011 NASA Strategic Plan [1] states that NASA will develop ``integrated architecture and capabilities for safe crewed and cargo missions beyond Low Earth Orbit.'' The technologies developed within this architecture will take astronauts beyond the Moon, to destinations such as Mars or asteroids and will most likely require the use of Nuclear Space Technologies (NSTs).While there are other proposals for novel power generation and propulsion, such as fusion technology, these technologies are immature and it may be decades before they have demonstrated feasibility; in contrast NSTs are readily available, proven to work in space, and flight qualified. However, NSTs such as nuclear thermal propulsion (NTP) may or may not reach completion - especially with the lack of a mission in which they may be developed. Prospects and progress in current NST projects, ranging from power sources to propulsion units, are explored within this study, mainly in the United States, with an overview of projects occurring in other countries. At the end of the study, recommendations are made in order to address budget and political realities, aerospace export control and nuclear non-proliferation programs, and international issues and potentials as related to NSTs. While this report is not fully comprehensive, the selection of chosen projects illustrates a range of issues for NSTs. Secondly, the reader would be keen to make a distinction between technologies that have flown in the past, projects that have been tested and developed yet not flown, and concepts that have not yet reached the bench for testing.

  4. Development and computational simulation of thermoelectric electromagnetic pumps for controlling the fluid flow in liquid metal cooled space nuclear reactors

    Thermoelectric Electromagnetic (TEEM) Pumps can be used for controlling the fluid flow in the primary and secondary circuits of liquid metal cooled space nuclear reactor. In order to simulate and to evaluate the pumps performance, in steady-state, the computer program BEMTE has been developed to study the main operational parameters and to determine the system actuation point, for a given reactor operating power. The results for each stage of the program were satisfactory, compared to experimental data. The program shows to be adequate for the design and simulating of direct current electromagnetic pumps. (author)

  5. Processing of solid solution, mixed uranium/refractory metal carbides for advanced space nuclear power and propulsion systems

    Knight, Travis Warren

    Nuclear thermal propulsion (NTP) and space nuclear power are two enabling technologies for the manned exploration of space and the development of research outposts in space and on other planets such as Mars. Advanced carbide nuclear fuels have been proposed for application in space nuclear power and propulsion systems. This study examined the processing technologies and optimal parameters necessary to fabricate samples of single phase, solid solution, mixed uranium/refractory metal carbides. In particular, the pseudo-ternary carbide, UC-ZrC-NbC, system was examined with uranium metal mole fractions of 5% and 10% and corresponding uranium densities of 0.8 to 1.8 gU/cc. Efforts were directed to those methods that could produce simple geometry fuel elements or wafers such as those used to fabricate a Square Lattice Honeycomb (SLHC) fuel element and reactor core. Methods of cold uniaxial pressing, sintering by induction heating, and hot pressing by self-resistance heating were investigated. Solid solution, high density (low porosity) samples greater than 95% TD were processed by cold pressing at 150 MPa and sintering above 2600 K for times longer than 90 min. Some impurity oxide phases were noted in some samples attributed to residual gases in the furnace during processing. Also, some samples noted secondary phases of carbon and UC2 due to some hyperstoichiometric powder mixtures having carbon-to-metal ratios greater than one. In all, 33 mixed carbide samples were processed and analyzed with half bearing uranium as ternary carbides of UC-ZrC-NbC. Scanning electron microscopy, x-ray diffraction, and density measurements were used to characterize samples. Samples were processed from powders of the refractory mono-carbides and UC/UC 2 or from powders of uranium hydride (UH3), graphite, and refractory metal carbides to produce hypostoichiometric mixed carbides. Samples processed from the constituent carbide powders and sintered at temperatures above the melting point of UC

  6. Effects of backlash and dead band on temperature control of the primary loop of a conceptual nuclear Brayton space powerplant

    Petrick, E. J.

    1973-01-01

    An analytical study was made of the stability of a closed-loop liquid-lithium temperature control of the primary loop of a conceptual nuclear Brayton space powerplant. The operating point was varied from 20 to 120 percent of design. A describing-function technique was used to evaluate the effects of temperature dead band and control coupling backlash. From the system investigation, it was predicted that a limit cycle will not exist with a temperature dead band, but a limit cycle will not exist when backlash is present. The results compare favorably with a digital computer simulation.

  7. Off-design temperature effects on nuclear fuel pins for an advanced space-power-reactor concept

    Bowles, K. J.

    1974-01-01

    An exploratory out-of-reactor investigation was made of the effects of short-time temperature excursions above the nominal operating temperature of 990 C on the compatibility of advanced nuclear space-power reactor fuel pin materials. This information is required for formulating a reliable reactor safety analysis and designing an emergency core cooling system. Simulated uranium mononitride (UN) fuel pins, clad with tungsten-lined T-111 (Ta-8W-2Hf) showed no compatibility problems after heating for 8 hours at 2400 C. At 2520 C and above, reactions occurred in 1 hour or less. Under these conditions free uranium formed, redistributed, and attacked the cladding.

  8. Systematic evaluation program review of NRC Safety Topic VI-10.A associated with the electrical, instrumentation and control portions of the testing of reactor trip system and engineered safety features, including response time for the Dresden station, Unit II nuclear power plant

    This report documents the technical evaluation and review of NRC Safety Topic VI-10.A, associated with the electrical, instrumentation, and control portions of the testing of reactor trip systems and engineered safety features including response time for the Dresden II nuclear power plant, using current licensing criteria

  9. The Thermionic System Evaluation Test (TSET): Descriptions, limitations, and the involvement of the space nuclear power community

    Project and test planning for the Thermionic System Evaluation Test (TSET) Project began in August 1990. Since the formalization of the contract agreement two years ago, the TOPAZ-II testing hardware was delivered in May 1992. In the months since the delivery of the test hardware, Russians and Americans working side-by-side installed the equipment and are preparing to begin testing in early 1993. The procurement of the Russian TOPAZ-II unfueled thermionic space nuclear power system (SNP) provides a unique opportunity to understand a complete thermionic system and enhances the possibility for further study of this type of power conversion for space applications. This paper will describe the program and test article, facility and test article limitations, and how the government and industry are encouraged to be involved in the program

  10. A compact radiation monitoring data acquisition system for space critical nuclear installations

    With the increased public concern for the harmful effects of nuclear radiation, it has become a mandatory requirement for all the nuclear installations to maintain the radiation levels within the permissible limits during the normal plant operation and also to initiate appropriate actions to prevent the spread of radioactivity during abnormal incidents. This paper describes the details of a compact radiation monitoring system being developed by using an industrial PC/386 computer for a nuclear reactor. The system is designed by adopting a modular I/O architecture for easy maintenance and system upgradation and provides easy to use menu-driven user interactions. This paper highlights the details of system architecture, user interface and the diagnostic features built in to the system in order to improve the system usage and reliability. 2 refs., 2 figs

  11. Assessment of radiation shielding materials for protection of space crews using CR-39 plastic nuclear track detector

    A significant obstacle to long duration human space exploration such as the establishment of a permanent base on the surface of the Moon or a human mission to Mars is the risk posed by prolonged exposure to space radiation. In order to keep mission costs at acceptable levels while simultaneously minimizing the risk from radiation to space crew health and safety, a judicious use of optimized shielding materials will be required. We have undertaken a comprehensive study using CR-39 plastic nuclear track detector (PNTD) to characterize the radiation shielding properties of a range of materials-both common baseline materials such as Al and polyethylene, and novel multifunctional materials such as carbon composites-at heavy ion accelerators. The study consists of analyzing CR-39 PNTD exposed in front of and behind shielding targets of varying composition and at a number of depths (target thicknesses) relevant to the development and testing of materials for space radiation shielding. Most targets consist of 10 cm x 10 cm slabs of solid materials ranging in thickness from 1 to >30 g/cm2. Exposures have been made to beams of C, O, Ne, Si, Ar, and Fe at energies ranging from 290 MeV/amu to 1 GeV/amu at the National Institute of Radiological Sciences HIMAC and the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory. Analysis of the exposed detectors yields LET spectrum, dose, and dose equivalent as functions of target depth and composition, and incident heavy ion charge, energy, and fluence. Efforts are currently underway to properly weigh and combine these results into a single quantitative estimate of a material's ability to shield space crews from the interplanetary galactic cosmic ray flux.

  12. Lasers from fission (gaseous core reactors and nuclear pumped lasers for space power generation and transmission)

    The energization of lasers directly by nuclear reactions has recently been achieved. In experiments conducted jointly by the University of Florida and Los Alamos Scientific Laboratory, New Mexico, a helium-xenon laser was directly pumped by fission fragments. The obtained laser wavelength was 3.5 μm. A group of researchers at the Sandia Corporation in Albuquerque, New Mexico, was successful in energizing a carbon monoxide laser by fission fragments at wavelengths in the 5-μm band. At the University of Illinois lasing was achieved at wavelengths of 8629 A and 9393 A in a neon-nitrogen mixture. A program of gaseous core reactor research is underway with experiments being conducted at the Los Alamos Scientific Laboratory in New Mexico, U.S.A. The program utilizes a beryllium moderator-reflector, forming a cylindrical cavity of 1 m diameter and 1 m length. This system and associated control system hardware, uses components from the previous ROVER nuclear rocket program. Various configurations of canisters containing enriched gaseous uraniumhexafluoride fuel are inserted into the reactor cavity for research on neutronics and nuclear induced optical radiation. Critical mass, control swing and the effects of poison were measured by simulating enriched uranium hexafluoride fuel with uranium foils, which were placed in homogeneous and inhomogeneous distributions in the cavity. Critical mass was determined at about 6 kg 93% enriched 235 uranium. A uranium hexafluoride canister system was built for safe operation in the reactor cavity and for physics measurements and observations at nuclear criticality. It is anticipated that this work will result in the demonstration of principles of a new type of nuclear power reactor, and of laser output from such a reactor. (author)

  13. Advanced Magnetic-Nuclear Power Systems for Reliability Demanding Applications Including Deep Space Missions

    Tsvetkov, Pavel; Guy, Troy

    2010-01-01

    The MAGNUS concept, which is based on the FFMCR approach, offers space power and propulsion technology with a number of unique characteristics such as: ï‚· Direct FF energy conversion is uniquely suitable for space operation; ï‚· High efficiency DEC promises reduced thermal control and radiators; ï‚· High specific impulse allows short trip times and extends exploration to the outer reaches of the solar system and beyond; ï‚· Achievability of long-term operation assures power for missions with...

  14. Space Exploration Initiative Fuels, Materials and Related Nuclear Propulsion Technologies Panel

    Bhattacharyya, S. K.; Olsen, C.; Cooper, R.; Matthews, R. B.; Walter, C.; Titran, R. J.

    1993-01-01

    This report was prepared by members of the Fuels, Materials and Related Technologies Panel, with assistance from a number of industry observers as well as laboratory colleagues of the panel members. It represents a consensus view of the panel members. This report was not subjected to a thorough review by DOE, NASA or DoD, and the opinions expressed should not be construed to represent the official position of these organizations, individually or jointly. Topics addressed include: requirement for fuels and materials development for nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP); overview of proposed concepts; fuels technology development plan; materials technology development plan; other reactor technology development; and fuels and materials requirements for advanced propulsion concepts.

  15. High Power Nuclear Electric Propulsion (NEP) for Cargo and Propellant Transfer Missions in Cislunar Space

    Falck, Robert D.; Borowski, Stanley K.

    2003-01-01

    The performance of Nuclear Electric Propulsion (NEP) in transporting cargo and propellant from Low Earth Orbit (LEO) to the first Earth-Moon Lagrange point (EML1) is examined. The baseline NEP vehicle utilizes a fission reactor system with Brayton power conversion for electric power generation to power multiple liquid hydrogen magnetoplasmadynamic (MPD) thrusters. Vehicle characteristics and performance levels are based on technology availability in a fifteen to twenty year timeframe. Results of numerical trajectory analyses are also provided.

  16. Evaluation of high-performance space nuclear electric generators for electric propulsion application

    Woodcock, Gordon

    2002-01-01

    Electric propulsion applications are enhanced by high power-to-mass ratios for their electric power sources. At multi-megawatt levels, we can expect thrust production systems to be less than 5 kg/kWe. Application of nuclear electric propulsion to human Mars missions becomes an attractive alternative to nuclear thermal propulsion if the propulsion system is less than about 10 kg/kWe. Recent references have projected megawatt-plus nuclear electric sources at specific mass values from less than 1 kg/kWe to about 5 kg/kWe. Various assumptions are made regarding power generation cycle (turbogenerator; MHD) and reactor heat source design. The present paper compares heat source and power generation options on the basis of a parametric model that emphasizes heat transfer design and realizable hardware concepts. Pressure drop (important!) is included in the power cycle analysis, and MHD and turbogenerator cycles arc compared. Results indicate that power source specific mass less than 5 kg/kWe is attainable, even if peak temperatures achievable are limited to 1500 K. Projections of specific mass less than 1 kg/kWe are unrealistic, even at the highest peak temperatures considered. .

  17. The Nuclear Thermal Propulsion Stage (NTPS): A Key Space Asset for Human Exploration and Commercial Missions to the Moon

    Borowski, Stanley K.; McCurdy, David R.; Burke, Laura M.

    2014-01-01

    The nuclear thermal rocket (NTR) has frequently been discussed as a key space asset that can bridge the gap between a sustained human presence on the Moon and the eventual human exploration of Mars. Recently, a human mission to a near Earth asteroid (NEA) has also been included as a "deep space precursor" to an orbital mission of Mars before a landing is attempted. In his "post-Apollo" Integrated Space Program Plan (1970 to 1990), Wernher von Braun, proposed a reusable Nuclear Thermal Propulsion Stage (NTPS) to deliver cargo and crew to the Moon to establish a lunar base initially before sending human missions to Mars. The NTR was selected because it was a proven technology capable of generating both high thrust and high specific impulse (Isp approx. 900 s)-twice that of today's best chemical rockets. During the Rover and NERVA programs, 20 rocket reactors were designed, built and successfully ground tested. These tests demonstrated the (1) thrust levels; (2) high fuel temperatures; (3) sustained operation; (4) accumulated lifetime; and (5) restart capability needed for an affordable in-space transportation system. In NASA's Mars Design Reference Architecture (DRA) 5.0 study, the "Copernicus" crewed NTR Mars transfer vehicle used three 25 klbf "Pewee" engines-the smallest and highest performing engine tested in the Rover program. Smaller lunar transfer vehicles-consisting of a NTPS with three approx. 16.7 klbf "SNRE-class" engines, an in-line propellant tank, plus the payload-can be delivered to LEO using a 70 t to LEO upgraded SLS, and can support reusable cargo delivery and crewed lunar landing missions. The NTPS can play an important role in returning humans to the Moon to stay by providing an affordable in-space transportation system that can allow initial lunar outposts to evolve into settlements capable of supporting commercial activities. Over the next decade collaborative efforts between NASA and private industry could open up new exploration and commercial

  18. A preliminary assessment of reactor candidate technologies for a 20 kWe space nuclear Brayton system

    In 1983, a cooperative program between the French Centre National d'Etudes Spaciales (CNES) and the Commissariat a l'Energie Atomique (CEA) was initiated to investigate the possible development of 20 to 200 kWe Brayton nuclear space systems. After the completion of the preliminary design of a reference 200 kWe turboelectric power system known as ERATO in 1986 (Carre et al. 1987), a second 3-year study phase was initiated. The objective of this phase was to assess the various reactor candidate technologies and system design options for 20 kWe power level for meeting the projected electric needs of the first European space missions (Carre et al. 1988). This paper presents the results of the design studies of three reference design concepts of 20 kWe turboelectric power systems covering a wide range of reactor temperatures and relevant material and reactor design technologies. Additionally the critical technology issues of the candidate systems, and other criteria relevant to the space missions are identified. The participation of the French industry in the present design activity is so far restricted to predesign studies of crucial components such as the turbomachinery and the reactor control actuators, and integration studies of the power system into the Ariane V launcher

  19. Power monitoring in space nuclear reactors using silicon carbide radiation detectors

    Ruddy, Frank H.; Patel, Jagdish U.; Williams, John G.

    2005-01-01

    Space reactor power monitors based on silicon carbide (SiC) semiconductor neutron detectors are proposed. Detection of fast leakage neutrons using SiC detectors in ex-core locations could be used to determine reactor power: Neutron fluxes, gamma-ray dose rates and ambient temperatures have been calculated as a function of distance from the reactor core, and the feasibility of power monitoring with SiC detectors has been evaluated at several ex-core locations. Arrays of SiC diodes can be configured to provide the required count rates to monitor reactor power from startup to full power Due to their resistance to temperature and the effects of neutron and gamma-ray exposure, SiC detectors can be expected to provide power monitoring information for the fill mission of a space reactor.

  20. SP-100 nuclear space power reactor system hardware and testing progress

    The SP-100 Space Reactor System was established by agencies of the US government as the system of choice to meet the nation's long lifetime, high reliability space power needs in the 10's to 100's of kWe power range. SP-100 is compatible with all power conversion technologies that can utilize reactor coolant temperatures ≤ 1,350 K. The technologies incorporated in SP-100 are directly applicable to earth orbiting satellites, planetary probes or surface power for commercial, military or civil missions. The most significant hardware and testing accomplishments that were made during the past year are reported in this summary paper, including fuel, fabrication technologies, control mechanisms, liquid metal pumps, lithium thaw behavior and characterization, and thermoelectric power conversion

  1. Nuclear

    This document proposes a presentation and discussion of the main notions, issues, principles, or characteristics related to nuclear energy: radioactivity (presence in the environment, explanation, measurement, periods and activities, low doses, applications), fuel cycle (front end, mining and ore concentration, refining and conversion, fuel fabrication, in the reactor, back end with reprocessing and recycling, transport), the future of the thorium-based fuel cycle (motivations, benefits and drawbacks), nuclear reactors (principles of fission reactors, reactor types, PWR reactors, BWR, heavy-water reactor, high temperature reactor of HTR, future reactors), nuclear wastes (classification, packaging and storage, legal aspects, vitrification, choice of a deep storage option, quantities and costs, foreign practices), radioactive releases of nuclear installations (main released radio-elements, radioactive releases by nuclear reactors and by La Hague plant, gaseous and liquid effluents, impact of releases, regulation), the OSPAR Convention, management and safety of nuclear activities (from control to quality insurance, to quality management and to sustainable development), national safety bodies (mission, means, organisation and activities of ASN, IRSN, HCTISN), international bodies, nuclear and medicine (applications of radioactivity, medical imagery, radiotherapy, doses in nuclear medicine, implementation, the accident in Epinal), nuclear and R and D (past R and D programmes and expenses, main actors in France and present funding, main R and D axis, international cooperation)

  2. A long term radiological risk model for plutonium-fueled and fission reactor space nuclear system

    This report describes the optimization of the RISK III mathematical model, which provides risk assessment for the use of a plutonium-fueled, fission reactor in space systems. The report discusses possible scenarios leading to radiation releases on the ground; distinctions are made for an intact reactor and a dispersed reactor. Also included are projected dose equivalents for various accident situations. 54 refs., 31 figs., 11 tabs

  3. Nuclear organization in the 3D space of the nucleus – cause or consequence?

    Nunez, Esperanza; Fu, Xiang-Dong; Rosenfeld, Michael G.

    2009-01-01

    Recent evidence suggests that dynamic three-dimensional genomic interactions in the nucleus exert critical roles in regulated gene expression. Here, we review a series of recent paradigm-shifting experiments that highlight the existence of specific gene networks within the self-organizing space of the nucleus. These gene networks, evidenced by long-range intra- and inter-chromosomal interactions, can be considered as the cause or consequence of regulatory biological programs. Changes in nucle...

  4. Feasibility study on polonium-209 as radioisotope fuel for space nuclear power

    We have investigated the performance and the production method of alternative isotopes of 238Pu as a radioisotope fuel for use in space radioisotope power generators. Polonium-209 has the possibility to be an alternative material of 238Pu. It has enough half-time of 102 years and the specific power of 490 W/kg. From the simulation, the beam current of 14 A with 40 MeV proton energy provides 1 kg/yr of 209Po annually. (author)

  5. Modeling of 3d Space-time Surface of Potential Fields and Hydrogeologic Modeling of Nuclear Waste Disposal Sites

    Shestopalov, V.; Bondarenko, Y.; Zayonts, I.; Rudenko, Y.

    Introduction After the Chernobyl Nuclear Power Plant (CNPP) disaster (04.26.1986) a huge amount (over 2000 sq. km) of nuclear wastes appeared within so-called "Cher- nobyl Exclusion Zone" (CEZ). At present there are not enough storage facilities in the Ukraine for safe disposal of nuclear wastes and hazardous chemical wastes. The urgent problem now is safe isolation of these dangerous wastes. According to the developed state program of radioactive waste management, the construction of a na- tional storage facility of nuclear wastes is planned. It is also possible to create regional storage facilities for hazardous chemical wastes. The region of our exploration cov- ers the eastern part of the Korosten Plutone and its slope, reaching the CNPP. 3D Space-Time Surface Imaging of Geophysical Fields. There are only three direct meth- ods of stress field reconstruction in present practice, namely the field investigations based on the large-scale fracturing tests, petrotectonic and optical polarization meth- ods. Unfortunately, all these methods are extremely laborious and need the regular field tests, which is difficult to conduct in the areas of anisotropic rock outcrops. A compilation of magnetic and gravity data covering the CNPP area was carried out as a prelude to an interpretation study. More than thirty map products were generated from magnetic, gravity and geodesy data to prepare the 3D Space-Time Surface Images (3D STSI). Multi-layer topography and geophysic surfaces included: total magnetic intensity, isostatically-corrected Bouguer gravity, aspect and slope, first and second derivatives, vertical and horizontal curvature, histogram characteristics and space cor- relation coefficients between the gradient fields. Many maps shows the first and sec- ond derivatives of the potential fields, with the results of lineament (edge) structure detection superimposed. The lineament or edges of the potential fields are located from maximal gradient in many directions

  6. Characterization of electrohydrodynamic heat transport components in a space-type nuclear reactor

    Lipchitz, A.; Harvel, G., E-mail: adam.lipchitz@uoit.ca [Univ. of Ontario Inst. of Tech., Faculty of Energy Systems and Nuclear Sciences, Oshawa, Ontario (Canada)

    2010-07-01

    The paper characterizes and describes the design of a capillary pumped loop with an EHD enhanced evaporator for use in a space reactor. The evaporator uses a wick to transfer the vapour and heat to a vapour section where the vapour is pumped using a EHD gas pump. The vapour is then transferred to a condenser where it is condensed into a liquid and recirculated after the heat has been removed. The design is shown in concept to be an effective method of heat transport in zero and microgravity environments. (author)

  7. Space monitoring of temperature regime of Semipalatinsk nuclear test site: 10 years of observations

    A brief description of the results of temperature anomaly routine research by specialists from Space Research Institute of Ministry of Education and Science of the Republic of Kazakhstan, revealed in 1997 within Semipalatinsk Test Site in the process of remote sounding of Kazakhstani territory, is given. Results of map analysis for snow cover, day and night temperatures and vegetation (during vegetation season) for the period since 1997 till 2006 testify a hypothesis on natural temperature anomaly, though there is a number of questions to be answered for further complex investigation. (author)

  8. Nuclear radiation interference and damage effects in charged particle experiments for extended space missions.

    Trainor, J. H.; Teegarden, B. J.

    1971-01-01

    Demonstration that meaningful galactic and solar cosmic radiation measurements can be carried out on deep space missions. The radioisotopic thermoelectric generators (RTGs) which must be used as a source of power and perhaps of heat are a problem, but with proper separation from the experiments, with orientation, and with some shielding the damage effects can be reduced to an acceptable level. The Pioneer spacecraft are crucial in that they are targeted at the heart of Jupiter's radiation belts, and should supply the details of those belts. The subsequent Grand Tour opportunities can be selected for those periods which result in larger distances of closest approach to Jupiter if necessary.

  9. Parameter study of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239c

    Smith, W.W.; Layton, J.P.

    1976-09-13

    The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. The NUROC3A systems analysis code was designed to provide the user with performance characteristics of the dual-mode system. Volume 3 describes utilization of the NUROC3A code to produce a detailed parameter study of the system.

  10. Spacer grids for laterally supporting and spacing rod -like or tube-like elements and methods of spacing and laterally supporting fuel rods within spacer grids of nuclear fuel rod assemblies

    New designs of spacer grids for laterally supporting and spacing rod-like or tube-like elements and methods of spacing and laterally supporting fuel rods within spacer grids of nuclear fuel rod assemblies are described. The invention consists of efficient, economical apparatus and method for inserting fuel rods into cells of a grid plate lattice that utilize protrusions to positively space and support the fuel elements or rods without marring the fuel surfaces of the elements or rods and a versatile grid plate design adaptable for supporting the tubes of vapor generators, shell and tube heat exchangers and the like. (U.K.)

  11. High Temperature Nanocomposites For Nuclear Thermal Propulsion and In-Space Fabrication by Hyperbaric Pressure Laser Chemical Vapor Deposition

    Maxwell, J. L.; Webb, N. D.; Espinoza, M.; Cook, S.; Houts, M.; Kim, T.

    Nuclear Thermal Propulsion (NTP) is an indispensable technology for the manned exploration of the solar system. By using Hyperbaric Pressure Laser Chemical Vapor Deposition (HP-LCVD), the authors propose to design and build a promising next-generation fuel element composed of uranium carbide UC embedded in a latticed matrix of highly refractory Ta4HfC5 for an NTP rocket capable of sustaining temperatures up to 4000 K, enabling an Isp of up to 1250 s. Furthermore, HP-LCVD technology can also be harnessed to enable 3D rapid prototyping of a variety of materials including metals, ceramics and composites, opening up the possibility of in-space fabrication of components, replacement parts, difficult-to-launch solar sails and panels and a variety of other space structures. Additionally, rapid prototyping with HP-LCVD makes a feasible "live off the land" strategy of interplanetary and interstellar exploration ­ the precursors commonly used in the technology are found, often in abundance, on other solar system bodies either as readily harvestable gas (e.g. methane) or as a raw material that could be converted into a suitable precursor (e.g. iron oxide into ferrocene on Mars).

  12. Space nuclear thermal propulsion program. Final report, September 1989-May 1995

    Haslett, R.A.

    1995-05-01

    The SNTP Program was an advanced technology development effort aimed at providing the Nation a new, dramatically higher performing rocket engine that would more than double the performance of the best conventional chemical rocket engines. The program consisted of three phases. Phase I ran from November 1987 through September 1989. The objective of this phase was to verify the feasibility of the Particle Bed Reactor (PBR) as the propulsion energy source for the upper stage of a ground-based Boost Phase Intercept (BPI) vehicle. The BPl mission was of interest to the Strategic Defense Initiative Organization (SDIO) who sponsored the program. Phase II started under SDIO control and was transferred to the Air Force (AF) in October 1991. The BPI mission was de-emphasized, and engine requirements were revised to satisfy more general AF space missions. The goal of Phase II was to perform a ground demonstration of a prototypical PBR engine.

  13. Applications of power beaming from space-based nuclear power stations

    Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 20000K and a liquid drop radiator to reject heat at temperatures of approx. 5000K. Higher RBR coolant temperatures (up to approx. 30000K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel

  14. The PEGASUS Drive: A nuclear electric propulsion system for the space exploration initiative

    The advantages of using electric propulsion for propulsion are well-known in the aerospace community. The high specific impulse, lower propellant requirements, and lower system mass make it a very attractive propulsion option for the Space Exploration Initiative (SEI), especially for the transport of cargo. One such propulsion system is the PEGASUS Drive (Coomes et al. 1987). In its original configuration, the PEGASUS Drive consisted of a 10-MWe power source coupled to a 6-MW magnetoplasmadynamic (MPD) thruster system. The PEGASUS Drive propelled a manned vechicle to Mars and back in 601 days. By removing the crew and their associated support systems from the space craft and by incorporating technology advances in reactor design and heat rejection systems, a second generation PEGASUS Drive can be developed with an alpha less than two. Utilizing this propulsion system, a 400-MT cargo vechicle, assembled and loaded in low Earth orbit (LEO), could deliver 262 MT of supplies and hardware to MARS 282 days after escaping Earth orbit. Upon arrival at Mars the transport vehicle would place its cargo in the desired parking orbit around Mars and then proceed to synchronous orbit above the desired landing sight. Using a laser transmitter, PEGASUS could provide 2-MW on the surface to operate automated systems deployed earlier and then provide surface power to support crew activities after their arrival. The additional supplies and hardware, coupled with the availability of megawatt levels of electric power on the Mars surface, would greatly enhance and even expand the mission options being considered under SEI

  15. Request for Naval Reactors Comment on Proposed PROMETHEUS Space Flight Nuclear Reactor High Tier Reactor Safety Requirements and for Naval Reactors Approval to Transmit These Requirements to Jet Propulsion Laboratory

    The purpose of this letter is to request Naval Reactors comments on the nuclear reactor high tier requirements for the PROMETHEUS space flight reactor design, pre-launch operations, launch, ascent, operation, and disposal, and to request Naval Reactors approval to transmit these requirements to Jet Propulsion Laboratory to ensure consistency between the reactor safety requirements and the spacecraft safety requirements. The proposed PROMETHEUS nuclear reactor high tier safety requirements are consistent with the long standing safety culture of the Naval Reactors Program and its commitment to protecting the health and safety of the public and the environment. In addition, the philosophy on which these requirements are based is consistent with the Nuclear Safety Policy Working Group recommendations on space nuclear propulsion safety (Reference 1), DOE Nuclear Safety Criteria and Specifications for Space Nuclear Reactors (Reference 2), the Nuclear Space Power Safety and Facility Guidelines Study of the Applied Physics Laboratory

  16. Two generic concepts for space propulsion based on thermal nuclear fusion

    Gabrielli, R. A.; Petkow, D.; Herdrich, G.; Laufer, R.; Röser, H.-P.

    2014-08-01

    In the present work, two different concepts for fusion based space propulsion are compared. While the first concept is based solely on propulsion by hypothetic ejection of fusion products and hence may be called ash drive, the second one uses an additional coolant for thrust enhancement. Since this coolant was initially assumed to be gaseous and since it is doing most of the propulsion work, the name of “working gas drive” has been proposed. Propulsive characteristics for both types are evaluated for four fusion reactant couples (D-T; D-3He; 3He-3He; 11B-p). In working gas drives, only hydrogen is considered as coolant due to its exceptionally good caloric and propulsive properties. The results of comparative studies show that while ash drives excel working gas drives in terms of specific impulse the latter yield considerably more thrust than ash drives. Another major drawback of the ash drives is relatively small thrust efficiencies. The plasma power has to be disposed of nearly entirely as waste heat leading to prohibitive radiator masses.

  17. Thermal emittance measurements on candidate refractory materials for application in nuclear space power systems

    The development of a highly efficient General Purpose Heat Source (GPHS) space power system requires that all of the available thermal energy from the GPHS modules be utilized in the most thermally efficient manner. This includes defining the heat transfer/thermal gradient profile between the surface of the GPHS's and the surface of the energy converter's hot end whose geometry is dependent on the converter technology selected. Control of the radiant heat transfer between these two surfaces is done by regulating how efficiently the selected converter's hot end surface can reject heat compared to a perfect blackbody, i.e. its infrared emittance. Several refractory materials of interest including niobium-1% zirconium, molybdenum-44.5% rhenium and L-605 (a cobalt-based alloy) were subjected to various surface treatments (grit blasting with either SiC or WC particulates) and heat treatments (up to 1198 K for up to 3000 hours). Room temperature infrared emittance values were then obtained using two different infrared reflectometers. Grit blasting with either SiC or WC tended to increase the emittance of flat or curved L-605 coupons by ∼0.2-0.3 independent of heat treatment. Heat treating L-605 coupons under 773 K for up to 2000 hours had only a slight effect on their emittance, while heat treating L-605 coupons at 973 K for over 150 hours appeared to significantly increase their emittance. For the temperatures and times studied here, the emittance values obtained on niobium-1% zirconium and molybdenum-44.5% rhenium coupons were independent of heat treat times and temperatures (except for the niobium-1% zirconium coupon that was heat treated at 1198 K for 150 hours)

  18. Testimony [on space nuclear power] before the Subcommittee on Energy Research and Production of the Committee on Science and Technology, US House of Representatives

    This brief presentation consists of four parts: first, a few introductory comments about space nuclear power technology; second, a description of activities currently underway at Martin Marietta Energy Systems; third, a discussion of future directions at Martin Marietta Energy Systems; and fourth, some recommendations

  19. The rationale/benefits of nuclear thermal rocket propulsion for NASA's lunar space transportation system

    Borowski, S.K.

    1994-09-01

    The solid core nuclear thermal rocket (NTR) represents the next major evolutionary step in propulsion technology. With its attractive operating characteristics, which include high specific impulse (approximately 850-1000 s) and engine thrust-to-weight (approximately 4-20), the NTR can form the basis for an efficient lunar space transportation system (LTS) capable of supporting both piloted and cargo missions. Studies conducted at the NASA Lewis Research Center indicate that an NTR-based LTS could transport a fully-fueled, cargo-laden, lunar excursion vehicle to the Moon, and return it to low Earth orbit (LEO) after mission completion, for less initial mass in LEO than an aerobraked chemical system of the type studied by NASA during its '90-Day Study.' The all-propulsive NTR-powered LTS would also be 'fully reusable' and would have a 'return payload' mass fraction of approximately 23 percent--twice that of the 'partially reusable' aerobraked chemical system. Two NTR technology options are examined--one derived from the graphite-moderated reactor concept developed by NASA and the AEC under the Rover/NERVA (Nuclear Engine for Rocket Vehicle Application) programs, and a second concept, the Particle Bed Reactor (PBR). The paper also summarizes NASA's lunar outpost scenario, compares relative performance provided by different LTS concepts, and discusses important operational issues (e.g., reusability, engine 'end-of life' disposal, etc.) associated with using this important propulsion technology.

  20. Pore space characterization in carbonate rocks - Approach to combine nuclear magnetic resonance and elastic wave velocity measurements

    Müller-Huber, Edith; Schön, Jürgen; Börner, Frank

    2016-04-01

    Pore space features influence petrophysical parameters such as porosity, permeability, elastic wave velocity or nuclear magnetic resonance (NMR). Therefore they are essential to describe the spatial distribution of petrophysical parameters in the subsurface, which is crucial for efficient reservoir characterization especially in carbonate rocks. While elastic wave velocity measurements respond to the properties of the solid rock matrix including pores or fractures, NMR measurements are sensitive to the distribution of pore-filling fluids controlled by rock properties such as the pore-surface-to-pore-volume ratio. Therefore a combination of both measurement principles helps to investigate carbonate pore space using complementary information. In this study, a workflow is presented that delivers a representative average semi-axis length of ellipsoidal pores in carbonate rocks based on the pore aspect ratio received from velocity interpretation and the pore-surface-to-pore-volume ratio Spor as input parameters combined with theoretical calculations for ellipsoidal inclusions. A novel method to calculate Spor from NMR data based on the ratio of capillary-bound to movable fluids and the thickness of the capillary-bound water film is used. To test the workflow, a comprehensive petrophysical database was compiled using micritic and oomoldic Lower Muschelkalk carbonates from Germany. The experimental data indicate that both mud-dominated and grain-dominated carbonates possess distinct ranges of petrophysical parameters. The agreement between the predicted and measured surface-to-volume ratio is satisfying for oomoldic and most micritic samples, while pyrite or significant sample heterogeneity may lead to deviations. Selected photo-micrographs and scanning electron microscope images support the validity of the estimated representative pore dimensions.

  1. The Evaluation of Lithium Hydride for Use in a Space Nuclear Reactor Shield, Including a Historical Perspective

    D. Poeth

    2005-12-09

    LiH was one of the five primary shield materials the NRPCT intended to develop (along with beryllium, boron carbide, tungsten, and water) for potential Prometheus application. It was also anticipated that {sup 10}B metal would be investigated for feasibility at a low level of effort. LiH historically has been selected as a low mass, neutron absorption material for space shields (Systems for Nuclear Auxiliary Power (SNAP), Topaz, SP-100). Initial NRPCT investigations did not produce convincing evidence that LiH was desirable or feasible for a Prometheus mission due to material property issues (primarily swelling and hydrogen cover gas containment), and related thermal design complexity. Furthermore, if mass limits allowed, an option to avoid use of LiH was being contemplated to lower development costs and associated risks. However, LiH remains theoretically the most efficient neutron shield material per unit mass, and, with sufficient testing and development, could be an optimal material choice for future flights.

  2. Concept, design approaches suited to space nuclear power systems in the range of 20 kWe

    Given the variety of possible missions and flight dates, it seems advisable to widen the basis for future technical choices within the French preliminary studies of 20-kWe space nuclear power systems. In addition to the fast spectrum, liquid metal-cooled reactor presently considered as a reference, shorter development term system, gas-and Na(K)-cooled thermal spectrum reactors are being investigated. The need for adequate ZrH moderator temperature conditions can be satisfied through a Brayton cycle conversion subsystem featuring two separate, high temperature-heat pipes and low temperature-pumped loop radiators. The penalty in efficiency and in radiator area, resulting from the wanted lower reactor inlet temperature, can be limited, particularly in the case of the higher temperature, gas-cooled reactor system. A multiple, pivoting tubes, low temperature radiator concept is proposed; it avoids an extension of the related structural support frame beyond the conversion subsystem region in flight configuration. Arrangements peculiar to small reactors and two-turbo-generator diagrams for reliability reasons are presented. Provisional, not yet optimized, thermal management mass estimates are evaluated

  3. Principle results of design and experimental-test works on space nuclear energy facility on thermoemission reactor-transformer base on fast neutrons

    At the S. P. Korolev Rocket-Space Corporation (RSC) 'Energy' for long time pilot and research works on space Nuclear Energy Facilities (NEF) of electric capacity from 150 to 500 kW and MW range in nuclear electric-rocket engine facilities (NEREF) of its base have been carried out. Peculiarity of Nuclear Energy Facility is application of thermal emission reactor-converter (TRC) on fast neutrons, application of pure lithium-7 isotope in the capacity of coolant, and the high-temperature niobium alloy in the capacity of construction materials, module design of TRC and NEF at all. Principal attention is paid to basing of nuclear and radiation safety for production, launching, commissioning and decommissioning of these facilities. At present at the RSC 'Energy' the main volume of pilot work is emphasized on the module scheme NEF with TRC of electric capacity from 150 kW to 800-1000 kW for electric power plants creation for both inhabited Lunar base, and mine and processing complex for industrial Moon development. In the paper different possibilities for effective use of NEF and NEREF uniform technologies for further space development are given

  4. Mathematical model for the preliminary analysis of dual-mode space nuclear fission solid core power and propulsion systems, NUROC3A. AMS report No. 1239a

    Grey, J.; Chow, S.

    1976-06-30

    The three-volume report describes a dual-mode nuclear space power and propulsion system concept that employs an advanced solid-core nuclear fission reactor coupled via heat pipes to one of several electric power conversion systems. Such a concept could be particularly useful for missions which require both relatively high acceleration (e.g., for planetocentric maneuvers) and high performance at low acceleration (e.g., on heliocentric trajectories or for trajectory shaping). The first volume develops the mathematical model of the system.

  5. Space space space

    Trembach, Vera

    2014-01-01

    Space is an introduction to the mysteries of the Universe. Included are Task Cards for independent learning, Journal Word Cards for creative writing, and Hands-On Activities for reinforcing skills in Math and Language Arts. Space is a perfect introduction to further research of the Solar System.

  6. Shell model calculation of the nuclear moments of 9Li in a 2hω space

    A recent measurement of the magnitude of quadrupole moment of the ground state of 9Li, Q( 9Li), finds that Vertical BarQ(9Li)/Q(7Li)Vertical Bar = 0.88 +- 0.18. A variety of shell-model calculations, using p-shell wave functions, predict Q(9Li)approx. =1.3Q( 7Li) and yield quadrupole moments whose magnitudes are approximately half the experimental values. Agreement between theory and experiment is improved when effective charges are used, although the results are still not completely satisfactory. A calculation of the wave functions of the low-lying states of 7Li and 9Li using a modified version of the Sussex matrix elements in a model space, including all 0hω and 2hω excitations, has been performed. The resulting value for Q( 9Li) was -3.46 fm2 as ray transitions in /sup 52,53/Cr and /sup 54,55/Mn have been observed using 7Li(51V,xn yp zα γ) fusion-evaporation reactions and γ-particle coincidence techniques. The experiment involved the same reaction at the same center-of-mass energy as the earlier work of Poletti et al., but with target and projectile interchanged. In the present work, eight additional transitions have been identified as occurring in 52Cr. This provides corroboration of results obtained more recently via 50Ti(α,2nγ)52Cr reaction studies. A simple, efficient approach to the spectroscopy of weakly populated nuclear states which provides for unambiguous isotopic assignments is thus demonstrated

  7. Causes and advantages of radical innovation: example of the space nuclear propulsion; Motivations et atouts de l`innovation radicale: l`exemple de la propulsion nucleaire spatiale

    Proust, E. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Direction des Reacteurs Nucleaires

    1997-12-31

    After a review of the principles underlying the nuclear propulsion and its application to space propulsion, the NERVA program, developed in the US in the 60`s, is summarized, with emphasis on the fuels that were studied in order to sustain very high temperature and variations (graphite matrix with uranium and zirconium carbides), and on the reactor design which led to the development of the PHOEBUS 2A reactor, the most powerful reactor ever constructed (4000 MW). Advantages of the nuclear propulsion for space transportation are still prominent, especially for a Moon permanent base and voyages to Mars. French researches are aimed at a cargo shuttle application between Earth and Moon orbits, with a reactor concept based on annular fuel elements and hydrogen radially passing through the fuel elements

  8. Advanced development and using of space nuclear power systems as a part of transport power supply modules for general purpose spacecraft

    Nuclear transport power systems (NTPS) can provide solving such important science, commerce and defense tasks in space as radar surveillance, information affording, global ecological monitoring, defense of Earth from dangerous space objects, manufacturing in space, investigations of asteroids, comets and solar systems close-quote planets (Kuzin et al. 1993a, 1993b). The creation of NTPS for real space systems, however, must be based on proved NTPS effectiveness in comparison with other power and propulsion systems such as, nonnuclear electric-rocket systems and so on. When the NTPS effectiveness is proved, the operation safety of such systems must be suited to the UN requirements for all stages of the life cycle in view of possible failures. A nuclear transport power module provides both a large amount of thermal and electrical power and a long acting time (about 6 endash 7 years after completing the delivery task). For this reason such module is featured with the high power supplying-mass delivery effectiveness and the considerable increasing of the total effectiveness of a spacecraft with the module. In the report, the such NTPS three types, namely the system on the base of thermionic reactor-converter with electric rocket propulsion system (ERPS), the dual mode thermionic nuclear power system with pumping of working fluid through the active reactor zone, and the system on the base of the nuclear thermal rocket engine technology is compared with the transport power modules on the base of solar power system from the point of view of providing the highest degree of the effectiveness. copyright 1996 American Institute of Physics

  9. Experimental Criticality Benchmarks for SNAP 10A/2 Reactor Cores

    Krass, A.W.

    2005-12-19

    This report describes computational benchmark models for nuclear criticality derived from descriptions of the Systems for Nuclear Auxiliary Power (SNAP) Critical Assembly (SCA)-4B experimental criticality program conducted by Atomics International during the early 1960's. The selected experimental configurations consist of fueled SNAP 10A/2-type reactor cores subject to varied conditions of water immersion and reflection under experimental control to measure neutron multiplication. SNAP 10A/2-type reactor cores are compact volumes fueled and moderated with the hydride of highly enriched uranium-zirconium alloy. Specifications for the materials and geometry needed to describe a given experimental configuration for a model using MCNP5 are provided. The material and geometry specifications are adequate to permit user development of input for alternative nuclear safety codes, such as KENO. A total of 73 distinct experimental configurations are described.

  10. Homeostatic restitution of cell membranes. Nuclear membrane lipid biogenesis and transport of protein from cytosol to intranuclear spaces.

    Amalia Slomiany, Maria Grabska, Bronislaw L. Slomiany

    2006-01-01

    Full Text Available Our studies on homeostatic restitution of cellular and subcellular membranes showed that vesicular intracellular transport is engaged in systematic and coordinated replacement of lipids and proteins in the membranes of the secretory, non-dividing epithelial cells (Slomiany et al., J. Physiol. Pharmacol. 2004; 55: 837-860. In this report, we present evidence on the homeostatic restitution of lipids in the biomembranes that constitute nuclear envelopes. We investigated nuclear membranes lipid synthesis by employing purified intact nuclei (IN, the outer nuclear membrane (ONM, the inner nuclear membrane (INM and the cell cytosol (CC. In contrast to Endoplasmic Reticulum (ER which in the presence of CC generates new biomembrane that forms ER vesicles transporting ER products to Golgi, the IN, ONM and INM are not producing transport vesicles. Instead, the newly synthesized lipids remain in the nuclear membranes. The membranes (INM, ONM of IN incubated with CC become enriched with newly synthesized phosphatidylcholine (PC, phosphatidylinositol (PI, phosphatidylinositol phosphates (PIPs and phosphatidic acid (PA. The incubation of separated ONM and INM with CC also enriched the membranes with IN specific lipids identified above. Moreover, the incubation of IN or its membranes with CC afforded retention of numerous CC proteins on the nuclear membrane. Here, we concentrated on 30kDa CC protein that displayed affinity to nuclear membrane PIP2. The 30kDa CC protein bound to PIP2 of IN, INM, and ONM. With IN, initially the PIP2-30kDa CC protein complex was detected on ONM, after 30-120 min of incubation, was found on INM and in nuclear contents. At the same time when the 30 kDa protein was released from INM and found in nuclear contents, the PIP2 of INM and ONM became undetectable, while the lipid extract from the membrane displaced from IN contained labeled PI only. Since ONM is an uninterrupted continuum of ER and INM, we speculate that the synthesis of

  11. Commemorative essay on the 1958 experimental nuclear detonation between the earth's Van allen-Vernow belts and the environmental holonomy of circumterrestrial space

    Here I write of circumterrestrial space (CTS) and the commemoration of the little known fact that 27 August 2004 coincides with the 46th anniversary of the detonation by the United States, mainly for specific purposes, of a small nuclear device in the lower ionosphere, 480 km above the surface of the earth near the equatorial northern hemisphere, over the Azores. We also discuss the anthropogenic threats to the holonomy of all components of the outer circumterrestrial spheres and the efforts that must be encouraged to preserve, for future generations, the earth's CTS, as a global commons. (Author)

  12. Nuclear energy propulsion in space; L'utilisation de l'energie nucleaire dans l'espace

    Raepsaet, X. [CEA Saclay, 91 - Gif sur Yvette (France). Dept. de Mecanique et de Technologie; Pempie, P. [Centre National d' Etudes Spatiales, CNES, 91 - Evry (France)

    2001-12-01

    Nuclear energy can be used under two different ways in spatial applications, first the most common is the production of electricity that is used to supply an electrical propulsion system. The second way is the thermal propulsion where the nuclear reactor is considered as a heat exchanger whose purpose is to heat a gas that will expand in a nozzle. The thermal propulsion implies that the nuclear fuel and some reactor components will have to sustain very high temperatures ( > 2000 K) and important temperature gradients over short time intervals. Because of size and mass constraints propulsion reactors require highly enriched uranium fuels, in such cases power densities reach 1 to 10 MW / liter of core, which is by 1 to 2 orders of magnitude bigger than in a PWR-type power reactor, this represents a true technological challenge. In this article 2 projects: ERATO concerning spatial power generation and MAPS concerning thermal propulsion are presented. (A.C.)

  13. Bimodal space nuclear power system with fast reactor and Topaz II-type single-cell TFE

    The paper deals with characteristics and conceptual studies of a bimodal space thermionic system with a fast reactor and single-cell TFEs which is designed to operate in two modes: rated power mode providing power supply to space vehicle-mounted systems with energy consumption level of 10 endash 80 kW(e) and forced thermal propulsion mode with thrust of 2200 N. copyright 1996 American Institute of Physics

  14. Bimodal space nuclear power system with fast reactor and Topaz II-type single-cell TFE

    Ponomarev-Stepnoi, N. N.; Usov, V. A.; Ogloblin, B. G.; Shalaev, A. I.; Klimov, A. V.; Kirillov, E. Ya.; Shumov, D. P.; Radchenko, I. S.; Nicolaev, Y. V.

    1996-03-01

    The paper deals with characteristics and conceptual studies of a bimodal space thermionic system with a fast reactor and single-cell TFEs which is designed to operate in two modes: rated power mode providing power supply to space vehicle-mounted systems with energy consumption level of 10-80 kW(e) and forced thermal propulsion mode with thrust of 2200 N.

  15. Nuclear energy technology

    Buden, David

    1992-01-01

    An overview of space nuclear energy technologies is presented. The development and characteristics of radioisotope thermoelectric generators (RTG's) and space nuclear power reactors are discussed. In addition, the policy and issues related to public safety and the use of nuclear power sources in space are addressed.

  16. Manned space flight nuclear system safety. Volume 3: Reactor system preliminary nuclear safety analysis. Part 2A: Accident model document, appendix

    1972-01-01

    The detailed abort sequence trees for the reference zirconium hydride (ZrH) reactor power module that have been generated for each phase of the reference Space Base program mission are presented. The trees are graphical representations of causal sequences. Each tree begins with the phase identification and the dichotomy between success and failure. The success branch shows the mission phase objective as being achieved. The failure branch is subdivided, as conditions require, into various primary initiating abort conditions.

  17. The Use of Nuclear Propulsion, Power and 'In-Situ' Resources for Routine Lunar Space Transportation and Commercial Base Development

    Borowski, Stanley K.

    2003-01-01

    This viewgraph presentation illustrates possible future strategies for solar system exploration supported by Nuclear Thermal Rocket (NTR) Propulsion. Topics addressed in the presentation include: lunar mining, Liquid Oxygen (LOX) augmented NTR (LANTR), 'Shuttle-Derived' Heavy Lift Vehicle (SDHLV) options for future human Lunar missions, and lunar-produced oxygen (LUNOX).

  18. Nuclear and Non-Ionizing Energy-loss of Electrons with Low and Relativistic Energies in Materials and Space Environment

    Boschini, M J; Gervasi, M; Giani, S; Grandi, D; Ivanchenko, V; Nieminem, P; Pensotti, S; Rancoita, P G; Tacconi, M

    2011-01-01

    The treatment of the electron-nucleus interaction based on the Mott differential cross section was extended to account for effects due to screened Coulomb potentials, finite sizes and finite rest masses of nuclei for electrons above 200 keV and up to ultra high energies. This treatment allows one to determine both the total and differential cross sections, thus, subsequently to calculate the resulting nuclear and non-ionizing stopping powers. Above a few hundreds of MeV, neglecting the effect due to finite rest masses of recoil nuclei the stopping power and NIEL result to be largely underestimated; while, above a few tens of MeV the finite size of the nuclear target prevents a further large increase of stopping powers which approach almost constant values.

  19. Measurements of shielding effects and nuclear abundances on board the International Space Station in the Lazio-Sirad and Altcriss Experiments.

    Casolino, M.; Altcriss Collaboration

    In this work we examine the effect of shielding on the nuclear abundance and particle flux on board the International Space Station The first measurements were performed during the Italian Soyuz 2 mission Lazio-Sirad experiment April 2005 using a set of multi-material nextel nomex polyethylene tiles placed in the angle of view of the Sileye-3 Alteino experiment Subsequently the ESA Altcriss project begun in 2005 continued and extended these measurements in a long duration campaign to perform these observations at different points inside the Russian section of the station Various sets of dosimeters shielded and unshielded are being used in parallel with the active detector In this work we will discuss the results of the Lazio-Sirad and the first measurements of the Altcriss campaign

  20. Applications of power beaming from space-based nuclear power stations. [Laser beaming to airplanes; microwave beaming to ground

    Powell, J.R.; Botts, T.E.; Hertzberg, A.

    1981-01-01

    Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 2000/sup 0/K and a liquid drop radiator to reject heat at temperatures of approx. 500/sup 0/K. Higher RBR coolant temperatures (up to approx. 3000/sup 0/K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel.

  1. A Spherical Torus Nuclear Fusion Reactor Space Propulsion Vehicle Concept for Fast Interplanetary Piloted and Robotic Missions

    Williams, C. H.; Borowski, S. K.; Dudzinski, L. A.; Juhasz, A. J.

    1999-11-01

    A conceptual space vehicle concept to support NASA's 21^st century requirements was designed to enable human, multi-month travel throughout the outer solar system. The design was predicated on an ignited, spherical torus fusion reactor (R=2.5 m; a=1.25 m) burning spin polarized D^3He fuel and operating at high beta (30%). Peaked plasma temperature (50 keV) and number density (5×10^20 m-3) profiles were used. Engineering design was performed on all major vehicle systems including fusion reactor, fast wave plasma heating, power conversion, magnetic nozzle (for direct plasma propulsion), tankage and others, with emphasis on 1D fusion power balance, operation physics, first wall, toroidal field coils, and heat transfer. Two related proof-of-concept experiments at OSU, LANL, and PPPL are discussed. Results showed a 108 mt crew habitat payload could be delivered to Saturn rendezvous in 214 days using 6,145 MW of plasma jet power.

  2. Application of wavelet analysis to the nuclear phase space study; Application de l`analyse en ondelettes a l`etude de l`espace des phases nucleaire

    Jouault, B. [Nantes Univ., 44 (France)

    1996-11-22

    The objective of this thesis is to present a methodology, based on the projection methods used in statistical physics and on the wavelet approach, which allows to obtain various classes of information. A coherent modelling was elaborated as the tools used for generating and solving the evolution equations, expressed in terms of pertinent variables, are based on common concepts. The property of scale separation of the wavelet analysis allows an approximation hierarchy based on the geometrical structure of phase space to be defined. This information structuration offers the opportunity of solving the evolution equations with various degrees of precision by controlling the information loss and avoiding the sampling methods of Monte Carlo type. The application of this methodology to the case of heavy ion collisions needs an entirely numerical treatment of the density matrix evolution equation. This implies a very precise level of description in order to take into account the important dissipation effects occurring in intermediate energy nuclear dynamics. A proper solution less expensive was adopted by using the wavelets analytically expressed, this entailing also the testing of model validity by comparing its results with the analytical solutions. This model takes into account the structure of the system wave functions, thus conserving the microscopical information. The present methodology can be applied also at other energy domains providing the nuclear systems are subject to transient non steady-state regimes. The wavelet analysis was used extensively in the field of signal processing particularly to extract from background a physical signal and also in the field of turbulence phenomena 152 refs.

  3. CHANDRA X-RAY AND HUBBLE SPACE TELESCOPE IMAGING OF OPTICALLY SELECTED KILOPARSEC-SCALE BINARY ACTIVE GALACTIC NUCLEI. I. NATURE OF THE NUCLEAR IONIZING SOURCES

    Kiloparsec-scale binary active galactic nuclei (AGNs) signal active supermassive black hole (SMBH) pairs in merging galaxies. Despite their significance, unambiguously confirmed cases remain scarce and most have been discovered serendipitously. In a previous systematic search, we optically identified four kpc-scale binary AGNs from candidates selected with double-peaked narrow emission lines at z = 0.1-0.2. Here, we present Chandra and Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging of these four systems. We critically examine and confirm the binary-AGN scenario for two of the four targets, by combining high angular resolution X-ray imaging spectroscopy with Chandra ACIS-S, better nuclear position constraints from WFC3 F105W imaging, and direct starburst estimates from WFC3 F336W imaging; for the other two targets, the existing data are still consistent with the binary-AGN scenario, but we cannot rule out the possibility of only one AGN ionizing gas in both merging galaxies. We find tentative evidence for a systematically smaller X-ray-to-[O III] luminosity ratio and/or higher Compton-thick fraction in optically selected kpc-scale binary AGNs than in single AGNs, possibly caused by a higher nuclear gas column due to mergers and/or a viewing angle bias related to the double-peak narrow-line selection. While our result lends some further support to the general approach of optically identifying kpc-scale binary AGNs, it also highlights the challenge and ambiguity of X-ray confirmation.

  4. The Structure of Nuclear Star Clusters in Nearby Late-type Spiral Galaxies from Hubble Space Telescope Wide Field Camera 3 Imaging

    Carson, Daniel J.; Barth, Aaron J.; Seth, Anil C.; den Brok, Mark; Cappellari, Michele; Greene, Jenny E.; Ho, Luis C.; Neumayer, Nadine

    2015-05-01

    We obtained Hubble Space Telescope/Wide Field Camera 3 imaging of a sample of ten of the nearest and brightest nuclear clusters (NCs) residing in late-type spiral galaxies, in seven bands that span the near-UV to the near-IR. Structural properties of the clusters were measured by fitting two-dimensional surface brightness profiles to the images using GALFIT. The clusters exhibit a wide range of structural properties, with F814W absolute magnitudes that range from ‑11.2 to ‑15.1 mag and F814W effective radii that range from 1.4 to 8.3 pc. For 6 of the 10 clusters in our sample, we find changes in the effective radius with wavelength, suggesting radially varying stellar populations. In four of the objects, the effective radius increases with wavelength, indicating the presence of a younger population that is more concentrated than the bulk of the stars in the cluster. However, we find a general decrease in effective radius with wavelength in two of the objects in our sample, which may indicate extended, circumnuclear star formation. We also find a general trend of increasing roundness of the clusters at longer wavelengths, as well as a correlation between the axis ratios of the NCs and their host galaxies. These observations indicate that blue disks aligned with the host galaxy plane are a common feature of NCs in late-type galaxies, but are difficult to detect in galaxies that are close to face-on. In color–color diagrams spanning the near-UV through the near-IR, most of the clusters lie far from single-burst evolutionary tracks, showing evidence for multi-age populations. Most of the clusters have integrated colors consistent with a mix of an old population (>1 Gyr) and a young population (∼100–300 Myr). The wide wavelength coverage of our data provides a sensitivity to populations with a mix of ages that would not be possible to achieve with imaging in optical bands only. The surface brightness profiles presented in this work will be used for future

  5. Space nuclear reactor program. Hearing before the Subcommittee on Energy Research and Production and the Subcommittee on Space Science and Applications of the Committee on Science and Technology, US House of Representatives, Ninety-Eighth Congress, First Session, May 24, 1983

    This report deals with the hearing on space nuclear power systems. From both civilian and defense perspectives, this Nation's space activities of the future will place greater demands upon the on-board electric power supply systems. The activities to be accomplished within the framework of the triagency agreement among DOE, NASA, and DARPA are reviewed. The status of the US technology base is presented in space reactor systems research and development from the viewpoint of a NASA laboratory, two DOE laboratories, and the principal industry participants in the Department's recent technology assessment study

  6. The Structure of Nuclear Star Clusters in Nearby Late-type Spiral Galaxies from Hubble Space Telescope Wide Field Camera 3 Imaging

    Carson, Daniel J; Seth, Anil C; Brok, Mark den; Cappelari, Michele; Greene, Jenny E; Ho, Luis C; Neumayer, Nadine

    2015-01-01

    We obtained Hubble Space Telescope/Wide Field Camera 3 imaging of a sample of ten of the nearest and brightest nuclear clusters residing in late-type spiral galaxies, in seven bands that span the near-ultraviolet to the near-infrared. Structural properties of the clusters were measured by fitting two-dimensional surface brightness profiles to the images using GALFIT. The clusters exhibit a wide range of structural properties. For six of the ten clusters in our sample, we find changes in the effective radius with wavelength, suggesting radially varying stellar populations. In four of the objects, the effective radius increases with wavelength, indicating the presence of a younger population which is more concentrated than the bulk of the stars in the cluster. However, we find a general decrease in effective radius with wavelength in two of the objects in our sample, which may indicate extended, circumnuclear star formation. We also find a general trend of increasing roundness of the clusters at longer waveleng...

  7. Assessment of the impact of neutronic/thermal-hydraulic coupling on the design and performance of nuclear reactors for space propulsion

    Aithal, S.M.; Aldemir, T.; Vafai, K. (Ohio State Univ., Columbus, OH (United States). Dept. of Mechanical Engineering)

    1994-04-01

    A series of studies has been performed to investigate the potential impact of the coupling between neutronics and thermal hydraulics on the design and performance assessment of solid core reactors for nuclear thermal space propulsion, using the particle bed reactor (PBR) concept as an example system. For a given temperature distribution in the reactor, the k[sub eff] and steady-state core power distribution are obtained from three-dimensional, continuous energy Monte Carlo simulations using the MCNP code. For a given core power distribution, determination of the temperature distribution in the core and hydrogen-filled annulus between the reflector and pressure vessel is based on a nonthermal equilibrium analysis. The results show that a realistic estimation of fuel, core size, and control requirements for PBRs using hydrogenous moderators, as well as optimization of the overall engine design, may require coupled neutronic/thermal-hydraulic studies. However, it may be possible to estimate the thermal safety margins and propellant exit temperatures based on power distributions obtained from neutronic calculations at room temperature. The results also show that, while variation of the hydrogen flow rate in the annulus has been proposed as a partial control mechanism for PBRs, such control mechanism may not be feasible for PBRs with high moderator-to-fuel ratios and hence soft core neutron spectra.

  8. Analysis of loss-of-coolant accident for a fast-spectrum lithium-cooled nuclear reactor for space-power applications

    Turney, G. E.; Petrik, E. J.; Kieffer, A. W.

    1972-01-01

    A two-dimensional, transient, heat-transfer analysis was made to determine the temperature response in the core of a conceptual space-power nuclear reactor following a total loss of reactor coolant. With loss of coolant from the reactor, the controlling mode of heat transfer is thermal radiation. In one of the schemes considered for removing decay heat from the core, it was assumed that the 4 pi shield which surrounds the core acts as a constant-temperature sink (temperature, 700 K) for absorption of thermal radiation from the core. Results based on this scheme of heat removal show that melting of fuel in the core is possible only when the emissivity of the heat-radiating surfaces in the core is less than about 0.40. In another scheme for removing the afterheat, the core centerline fuel pin was replaced by a redundant, constant temperature, coolant channel. Based on an emissivity of 0.20 for all material surfaces in the core, the calculated maximum fuel temperature for this scheme of heat removal was 2840 K, or about 90 K less than the melting temperature of the UN fuel.

  9. Measuring flow and pressure of lithium coolant under developmental testing of a high-temperature cooling system of a space nuclear power plant

    Sobolev, V. Ya.; Sinyavsky, V. V.

    2014-12-01

    Sub-megawatt space NPP use lithium as a coolant and niobium alloy as a structural material. In order to refine the lithium-niobium technology of the material and design engineering, lithium-niobium loops were worked out in RSC Energia, and they were tested at a working temperature of lithium equal to 1070-1300 K. In order to measure the lithium flow and pressure, special gauges were developed, which made possible the calibration and checkout of the loops without their dismantling. The paper describes the architecture of the electromagnetic flowmeter and the electromagnetic vibrating-wire pressure transducer (gauge) for lithium coolant in the nuclear power plant cooling systems. The operating principles of these meters are presented. Flowmeters have been developed for channel diameters ranging from 10 to 100 mm, which are capable of measuring lithium flows in the range of 0.1 to 30 L/s with the error of 3% for design calibration and 1% for volume graduation. The temperature error of the pressure transducers does not exceed 0.4% per 100 K; the nonlinearity and hysteresis of the calibration curve do not exceed 0.3 and 0.4%, respectively. The transducer applications are illustrated by the examples of results obtained from tests on the NPP module mockup and heat pipes of a radiation cooler.

  10. Nuclear Propulsion and Power Non-Nuclear Test Facility (NP2NTF): Preliminary Analysis and Feasibility Assessment Project

    National Aeronautics and Space Administration — Nuclear reactors, which power nuclear propulsion and power systems, and the nuclear radiation and residual radioactivity associated with these systems, impose...

  11. SP-100 Program: space reactor system and subsystem investigations

    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

  12. Space debris

    36 years ago, the Soviet Union sent the first space satellite, Sputnik 1, into its orbit. Since then, the number of satellites has been increasing continuous by. As a result, the atmospheric layers close to the earth are littered with debris from broken satellites and rockets. This includes about 30 abandoned nuclear reactions orbiting at a height of about 1000 km. The expected life of the reactors is higher than the half-life after which the activity level of the radioactive material will have fallen to a tolerable level. (orig./HP)

  13. Environmental Development Plan for space applications

    The Environmental Development Plan (EDP) identifies the planning and management requirements and schedules needed to evaluate and assess the environmental, health and safety aspects of the Space Applications Program. Environment is defined in its broadest sense to include environmental, health (occupational and public, safety, socioeconomic, legal, and institutional apsects. EDP has been limited to consideration of: (1) space nuclear power system nuclear fuel fabrication; (2) space nuclear power system heat source fabrication; (3) testing of subsystems and assembled systems; (4)research and development (R and D) in support of space nuclear system development; (5) nuclear system responses to launch and reentry accidents: and (6) nuclear system environmental behavior and recovery

  14. 2-Quasi-l-Nuclear Maps

    W. Shatanawi

    2005-01-01

    In this paper we generalize the well-known result which says that the composition of quasi-nuclear maps is nuclear. More precisely, we define what we call a 2-quasi-l -nuclear map between normed spaces, and we prove that the composition of a 2-quasi-l -nuclear map with a quasi- l -nuclear map is a pseudo-l -nuclear map. Also, we prove that a quasi-l -nuclear map is a 2-quasi-l -nuclear map. For a nuclear G\\infty -space, we prove that a linear map T between normed spaces is 2-quasi-...

  15. In Outer Space without a Space Suit?

    Bolonkin, Alexander

    2008-01-01

    The author proposes and investigates his old idea - a living human in space without the encumbrance of a complex space suit. Only in this condition can biological humanity seriously attempt to colonize space because all planets of Solar system (except the Earth) do not have suitable atmospheres. Aside from the issue of temperature, a suitable partial pressure of oxygen is lacking. In this case the main problem is how to satiate human blood with oxygen and delete carbonic acid gas (carbon dioxide). The proposed system would enable a person to function in outer space without a space suit and, for a long time, without food. That is useful also in the Earth for sustaining working men in an otherwise deadly atmosphere laden with lethal particulates (in case of nuclear, chemical or biological war), in underground confined spaces without fresh air, under water or a top high mountains above a height that can sustain respiration.

  16. Fuels for space nuclear power systems. 2. Compatibility of Tungsten and Molybdenum with UF4 and UF4-UO2 at 2000 to 2350 K

    Gas core nuclear reactors have been considered for both electrical power and propulsion in space since at least the 1950's. The particular advantage of gas core reactors lies in the extremely high temperatures at which they operate. This allows radiative rejection of waste heat, which is, of course, the only available mechanism in space. The nuclear design of these reactors is relatively straightforward. However, no critical gas core reactor has ever advanced beyond the design stage because of extreme, and in many cases unsolvable, materials compatibility problems. The present research has pursued materials for reactors using as fuel and working fluid mixtures containing UF4 that are either completely gaseous or two-phase at the operating temperature of the reactor. Temperatures in excess of 2000 K and resistance to fluorides are therefore the minimum requirements for materials to be used in these reactors. Of the limited number of possible refractory materials for use as the wall in this application, all of the ceramics have been eliminated in previous tests. Short-term coupon tests at up to 1800 K and near atmospheric pressure indicated that tungsten and molybdenum might be compatible with UF4. In this study, the temperature and duration of the tests were extended by using an encapsulation technique. Previous experiments performed in this laboratory showed that reaction of UF4 with containment materials other than the specimen being investigated complicated the results and were a common source of error. Furthermore, in previous experimental systems, the available exposure duration was limited by the time it took for a graphite vessel filled with UF4 and heated to the desired exposure temperature to run dry because of evaporation of UF4 and subsequent condensation on the vacuum chamber walls. The UF4 reacts with common furnace materials such as alumina, quartz, and graphite. For longer-term exposure, we therefore fabricated crucibles of the materials to be tested

  17. Nuclear percolation

    Nuclear multifragmentation and spallation reactions produced in medium and high energy collisions are viewed as a percolation phenomenon. Percolation criteria are defined in both real and momentum space and a ''compactness'' condition is imposed to the clusters. Under these conditions, nuclear systems behave like a two-dimensional site percolation model, exhibiting a rather well defined percolation threshold at psub(c) approx.= 0.6. The concentration p is correlated with the number of fast particles ejected in the first stage of the collision. The mass yield results from the superposition of cluster size distributions at different values of p. (orig.)

  18. Transportation concepts for space industrialization

    Murphy, J. T.

    1977-01-01

    Space shuttle and heavy lift launch vehicle concepts are described with attention to transportation cost trends. Chemical (LOX/LH2), nuclear, and electric propulsion systems are considered. Suggested space shuttle projects include the support of manned geosynchronous missions and the transfer of bulk cargo and large-delicate space structures from fabrication/assembly orbits to their operational locations. It is thought that development of the space shuttle will stimulate interest in space industrialization.

  19. Atoms for space

    Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig

  20. Atoms for space

    Buden, D.

    1990-10-01

    Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig.

  1. Nuclear technology for the year 2000

    Eighteen papers and abstracts are presented under the following session headings: space nuclear power, health physics and dosimetry, nuclear design and thermal hydraulics, nuclear diagnostics, and fusion technology and plasma physics. The papers were processed separately for the data base

  2. Space Technology in Support of Cooperative US-Ukraine Efforts to Mitigate the Damage at the Chornobyl Unit 4 Nuclear Power Plant

    Marzwell, N.; Lavery, D.; Holliday, M.; Osborn, J.

    1998-01-01

    For transitional economies like Ukraine that have legacies from the Soviet era of severe environmental damage due to accidents and years of neglect, space technology-based remote systems can play an important role in evaluating and remediating hazardous sites.

  3. The hearing at the Federal Constitutional Court on the nuclear phase-out. No space left for legal ''tricks''

    Can lawyers do magic? At least some lawyers believe (even) to do. But does this work? Observers of the hearing of the German Constitutional Court trying the nuclear phase and the revision of the German Atomic Act on 15/16 March 2016 may believe it. The German Constitutional Court is trying the constitutional complaint proceedings of E.ON, RWE and Vattenfall on the legality of nuclear phase-out in Germany, essentially to the question of the compatibility of this law with the fundamental rights of the operating companies, in particular their right to property, to freedom of occupation, to equal treatment and protection of legitimate expectations.

  4. Environmental Development Plan (EDP): space applications

    This Environmental Development Plan (EDP) identifies and examines the environmental, safety, health, and socioeconomic (ES and H) issues associated with the ongoing DOE Space Applications Program and the associated research, development, and demonstration programs. The EDP presents an ES and H research and development (R/D) program and strategy for timely resolutions of the issues and satisfaction of the associated requirements necessary for precluding impediments to the space nuclear systems technology. The EDP has been limited to the consideration of: (1) space nuclear power system nuclear fuel fabrication; (2) space nuclear power system heat source fabrication; (3) testing of subsystems and assembled systems; (4) R and D in support of space nuclear system development; (5) nuclear system responses to launch and reentry accidents; and (6) nuclear system environmental behavior and recovery

  5. Nuclear reactor theory

    This textbook is composed of two parts. Part 1 'Elements of Nuclear Reactor Theory' is composed of only elements but the main resource for the lecture of nuclear reactor theory, and should be studied as common knowledge. Much space is therefore devoted to the history of nuclear energy production and to nuclear physics, and the material focuses on the principles of energy production in nuclear reactors. However, considering the heavy workload of students, these subjects are presented concisely, allowing students to read quickly through this textbook. (J.P.N.)

  6. Wastes in space

    As human space activities have created more wastes on low and high Earth orbits over the past 50 years than the solar system injected meteorites over billions of years, this report gives an overview of this problem. It identifies the origins of these space debris and wastes (launchers, combustion residues, exploitation wastes, out-of-use satellites, accidental explosions, accidental collisions, voluntary destructions, space erosion), and proposes a stock list of space wastes. Then, it distinguishes the situation for the different orbits: low Earth orbit or LEO (traffic, presence of the International Space Station), medium Earth orbits or MEO (traffic, operating satellites, wastes), geostationary Earth orbit or GEO (traffic, operating satellites, wastes). It also discusses wastes and bacteria present on the moon (due to Apollo missions or to crash tests). It evokes how space and nuclear industry is concerned, and discusses the re-entry issue (radioactive boomerang, metallic boomerang). It also indicates elements of international law

  7. A variable-order time-dependent neutron transport method for nuclear reactor kinetics using analytically-integrated space-time characteristics

    Hoffman, A. J.; Lee, J. C. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI, 48109-2104 (United States)

    2013-07-01

    A new time-dependent neutron transport method based on the method of characteristics (MOC) has been developed. Whereas most spatial kinetics methods treat time dependence through temporal discretization, this new method treats time dependence by defining the characteristics to span space and time. In this implementation regions are defined in space-time where the thickness of the region in time fulfills an analogous role to the time step in discretized methods. The time dependence of the local source is approximated using a truncated Taylor series expansion with high order derivatives approximated using backward differences, permitting the solution of the resulting space-time characteristic equation. To avoid a drastic increase in computational expense and memory requirements due to solving many discrete characteristics in the space-time planes, the temporal variation of the boundary source is similarly approximated. This allows the characteristics in the space-time plane to be represented analytically rather than discretely, resulting in an algorithm comparable in implementation and expense to one that arises from conventional time integration techniques. Furthermore, by defining the boundary flux time derivative in terms of the preceding local source time derivative and boundary flux time derivative, the need to store angularly-dependent data is avoided without approximating the angular dependence of the angular flux time derivative. The accuracy of this method is assessed through implementation in the neutron transport code DeCART. The method is employed with variable-order local source representation to model a TWIGL transient. The results demonstrate that this method is accurate and more efficient than the discretized method. (authors)

  8. A variable-order time-dependent neutron transport method for nuclear reactor kinetics using analytically-integrated space-time characteristics

    A new time-dependent neutron transport method based on the method of characteristics (MOC) has been developed. Whereas most spatial kinetics methods treat time dependence through temporal discretization, this new method treats time dependence by defining the characteristics to span space and time. In this implementation regions are defined in space-time where the thickness of the region in time fulfills an analogous role to the time step in discretized methods. The time dependence of the local source is approximated using a truncated Taylor series expansion with high order derivatives approximated using backward differences, permitting the solution of the resulting space-time characteristic equation. To avoid a drastic increase in computational expense and memory requirements due to solving many discrete characteristics in the space-time planes, the temporal variation of the boundary source is similarly approximated. This allows the characteristics in the space-time plane to be represented analytically rather than discretely, resulting in an algorithm comparable in implementation and expense to one that arises from conventional time integration techniques. Furthermore, by defining the boundary flux time derivative in terms of the preceding local source time derivative and boundary flux time derivative, the need to store angularly-dependent data is avoided without approximating the angular dependence of the angular flux time derivative. The accuracy of this method is assessed through implementation in the neutron transport code DeCART. The method is employed with variable-order local source representation to model a TWIGL transient. The results demonstrate that this method is accurate and more efficient than the discretized method. (authors)

  9. Current questions concerning Space Law

    This report covers in part the legal problems connected with the use of nuclear sources in space. These problems were highlighted by the accidental fall of the Soviet statellite Cosmos-954 in Canadian territory in January 1978. The author describes the status of international law on the subject, the work in the United Nations and discusses the measures to be taken to define a code of practice use of nuclear sources in space. (NEA)

  10. New vision solar system exploration missions study: Analysis of the use of biomodal space nuclear power systems to support outer solar system exploration missions. Final report

    NONE

    1995-12-08

    This report presents the results of an analysis of the capability of nuclear bimodal systems to perform outer solar system exploration missions. Missions of interest include orbiter mission s to Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. An initial technology baseline consisting of a NEBA 10 kWe, 1000 N thrust, 850 s, 1500 kg bimodal system was selected, and its performance examined against a data base for trajectories to outer solar system planetary destinations to select optimal direct and gravity assisted trajectories for study. A conceptual design for a common bimodal spacecraft capable of performing missions to all the planetary destinations was developed and made the basis of end to end mission designs for orbiter missions to Jupiter, Saturn, and Neptune. Concepts for microspacecraft capable of probing Jupiter`s atmosphere and exploring Titan were also developed. All mission designs considered use the Atlas 2AS for launch. It is shown that the bimodal nuclear power and propulsion system offers many attractive option for planetary missions, including both conventional planetary missions in which all instruments are carried by a single primary orbiting spacecraft, and unconventional missions in which the primary spacecraft acts as a carrier, relay, and mother ship for a fleet of micro spacecraft deployed at the planetary destination.

  11. 17 CFR 240.10A-2 - Auditor independence.

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Auditor independence. 240.10A... Exchange Act of 1934 Reports Under Section 10a § 240.10A-2 Auditor independence. It shall be unlawful for an auditor not to be independent under § 210.2-01(c)(2)(iii)(B), (c)(4), (c)(6), (c)(7), and §...

  12. Nuclear Medicine

    ... Parents/Teachers Resource Links for Students Glossary Nuclear Medicine What is nuclear medicine? What are radioactive tracers? ... funded researchers advancing nuclear medicine? What is nuclear medicine? Nuclear medicine is a medical specialty that uses ...

  13. Invisible nuclear; converting nuclear

    This book consists of 14 chapters which are CNN era and big science, from East and West to North and South, illusory nuclear strategy, UN and nuclear arms reduction, management of armaments, advent of petroleum period, the track of nuclear power generation, view of energy, internationalization of environment, the war over water in the Middle East, influence of radiation and an isotope technology transfer and transfer armament into civilian industry, the end of nuclear period and the nuclear Nonproliferation, national scientific and technological power and political organ and executive organ.

  14. MicroRNA 10a marks regulatory T cells

    Jeker, Lukas T; Zhou, Xuyu; Gershberg, Kseniya;

    2012-01-01

    MicroRNAs (miRNAs) are crucial for regulatory T cell (Treg) stability and function. We report that microRNA-10a (miR-10a) is expressed in Tregs but not in other T cells including individual thymocyte subsets. Expression profiling in inbred mouse strains demonstrated that non-obese diabetic (NOD...... vitro TGF-ß-induced, iTregs do not express miR-10a unless cultured in the presence of retinoic acid (RA) which has been associated with increased stability of iTreg, suggesting that miR-10a might play a role in stabilizing Treg. However, genetic ablation of miR-10a neither affected the number and...

  15. Annual Conference on Nuclear and Space Radiation Effects, 15th, University of New Mexico, Albuquerque, N. Mex., July 18-21, 1978, Proceedings

    Simons, M.

    1978-01-01

    Radiation effects in MOS devices and circuits are considered along with radiation effects in materials, space radiation effects and spacecraft charging, SGEMP, IEMP, EMP, fabrication of radiation-hardened devices, radiation effects in bipolar devices and circuits, simulation, energy deposition, and dosimetry. Attention is given to the rapid anneal of radiation-induced silicon-sapphire interface charge trapping, cosmic ray induced errors in MOS memory cells, a simple model for predicting radiation effects in MOS devices, the response of MNOS capacitors to ionizing radiation at 80 K, trapping effects in irradiated and avalanche-injected MOS capacitors, inelastic interactions of electrons with polystyrene, the photoelectron spectral yields generated by monochromatic soft X radiation, and electron transport in reactor materials.

  16. Annual Conference on Nuclear and Space Radiation Effects, 18th, University of Washington, Seattle, WA, July 21-24, 1981, Proceedings

    Tasca, D. M.

    1981-01-01

    Single event upset phenomena are discussed, taking into account cosmic ray induced errors in IIL microprocessors and logic devices, single event upsets in NMOS microprocessors, a prediction model for bipolar RAMs in a high energy ion/proton environment, the search for neutron-induced hard errors in VLSI structures, soft errors due to protons in the radiation belt, and the use of an ion microbeam to study single event upsets in microcircuits. Basic mechanisms in materials and devices are examined, giving attention to gamma induced noise in CCD's, the annealing of MOS capacitors, an analysis of photobleaching techniques for the radiation hardening of fiber optic data links, a hardened field insulator, the simulation of radiation damage in solids, and the manufacturing of radiation resistant optical fibers. Energy deposition and dosimetry is considered along with SGEMP/IEMP, radiation effects in devices, space radiation effects and spacecraft charging, EMP/SREMP, and aspects of fabrication, testing, and hardness assurance.

  17. Nuclear Systems (NS): Technology Demonstration Unit (TDU) Project

    National Aeronautics and Space Administration — The Nuclear Systems Project demonstrates nuclear power technology readiness to support the goals of NASA’s Space Technology Mission Directorate. To this end,...

  18. Fuels for space nuclear power systems. 3. Innovative Semi-spherical Pb-Hf-Cu Shield for a Fissioning Plasma Core Reactor

    This study investigated the shielding materials and requirements for a fissioning plasma core reactor (FPCR) with a magnetohydrodynamic (MHD) power conversion system for multimegawatt space power and propulsion applications. The FPCR is a liquid-vapor core reactor concept operating with metallic uranium or uranium tetrafluoride (UF4) vapor as the fissioning fuel and alkali metals or their fluorides as working fluid in a closed Rankine cycle with MHD energy conversion. This concept is under study for its potential to provide space power at a low specific mass of 3 with a length-to-diameter ratio of one was selected. This design based on earlier gas core reactor studies incorporates a 50-cm BeO radial reflector with additional 25-cm-thick BeO disk-shaped reflectors at the top and bottom of the cylindrical core. Liquid hydrogen tanks for propulsion and refrigeration were modeled between the reactor/power generation complex and the payload/habitable regions of the vessel or space station and lying along the boom, which can be from 30 to 60 m in length. Although the liquid hydrogen is not very dense (∼0.1 g/cm3), there is a considerable amount present (50 t is commonly referenced). A model of this system was developed in the MCNP-4C general Monte Carlo code, which was used to calculate the dose rate at various distances from the power-generating system. Sources of both fission neutrons (prompt and delayed) and gamma rays (prompt and decay) from fission were modeled. The neutron sampling distribution was taken as a Watt fission spectrum. The energy distribution of gamma rays from fission was taken from Ref. 1 and consists of a total average of 12.15 gamma rays per fission with ∼70% < 1 MeV and 27% between 1 and 3 MeV. Various shield designs were modeled, and corresponding dose rates were calculated. A criterion of <10 rems/h to the payload module was established for all shield designs. It was assumed that for a manned station or vessel, additional shielding would be

  19. NESbase version 1.0: a database of nuclear export signals

    la Cour, T.; Gupta, Ramneek; Rapacki, Krzysztof;

    2003-01-01

    information of whether NES was shown to be necessary and/or sufficient for export, and whether the export was shown to be mediated by the export receptor CRM1. The compiled information was used to make a sequence logo of the Leucine-rich NESs, displaying the conservation of amino acids within a window of 25...

  20. China's nuclear programs and policies

    Economics and the futility of arms competition with the US and USSR has forced China to shift its nuclear effort to peaceful uses, although its current nuclear-deterrent warrants including China in arms negotiations. China's nuclear program began during the 1950s with an emphasis on weaponry and some development in space technology. Proponents of nuclear power now appear to have refuted the earlier arguments that nuclear-plant construction would be too slow, too dangerous and polluting, and too expensive and the idea that hydro resources would be adequate. The current leadership supports a serious nuclear-power-plant construction program. 6 references

  1. Annual Conference on Nuclear and Space Radiation Effects, 14th, College of William and Mary, Williamsburg, Va., July 12-15, 1977, Proceedings

    Stahl, R. H.

    1977-01-01

    Topics related to processing and hardness assurance are considered, taking into account the radiation hardening of CMOS technologies, technological advances in the manufacture of radiation-hardened CMOS integrated circuits, CMOS hardness assurance through process controls and optimized design procedures, the application of operational amplifiers to hardened systems, a hard off-the-shelf SG1524 pulse width modulator, and the gamma-induced voltage breakdown anomaly in a Schottky diode. Basic mechanisms are examined, giving attention to chemical and structural aspects of the irradiation behavior of SiO2 films on silicon, experimental observations of the chemistry of the SiO2/Si interface, leakage current phenomena in irradiated SOS devices, the avalanche injection of holes into SiO2, the low-temperature radiation response of Al2O3 gate insulators, and neutron damage mechanisms in silicon at 10 K. Other subjects discussed are related to radiation effects in devices and circuits, space radiation effects, and aspects of simulation, energy deposition, and dosimetry.

  2. Power engineering in space

    The long and reliable functioning of the space vehicles depends in many respects on the reliability of their power facilities. The solar batteries with the operating life of 10-15 years constitute the power basis of the operating space vehicles. The growing requirements of the space power engineering present the incentive for further development and improvement of the solar and storage batteries. The characteristics and operating life of the modern storage batteries of various types are presented. Apart from this the alternative projects of the space engines on the basis of the nuclear power facilities with the liquid metal (Na, Li) or gaseous (Na, He, Xe) coolants are developed in the USA, Germany and Russia, which make it possible to obtain the thermal (1-5 MW) and electric (50-100 kW) power capacity

  3. Multimegawatt Space Reactor Safety

    The Multimegawatt (MMW) Space Reactor Project supports the Strategic Defense Initiative Office requirement to provide reliable, safe, cost-effective, electrical power in the MMW range. Specifically, power may be used for neutral particle beams, free electron lasers, electromagnetic launchers, and orbital transfer vehicles. This power plant technology may also apply to the electrical power required for other uses such as deep-space probes and planetary exploration. The Multimegawatt Space Reactor Project, the Thermionic Fuel Element Verification Program, and Centaurus Program all support the Multimegawatt Space Nuclear Power Program and form an important part of the US Department of Energy's (DOE's) space and defense power systems activities. A major objective of the MMW project is the development of a reference flight system design that provides the desired levels of public safety, health protection, and special nuclear material (SNM) protection when used during its designated missions. The safety requirements for the MMW project are a hierarchy of requirements that consist of safety requirements/regulations, a safety policy, general safety criteria, safety technical specifications, safety design specifications, and the system design. This paper describes the strategy and philosophy behind the development of the safety requirements imposed upon the MMW concept developers. The safety organization, safety policy, generic safety issues, general safety criteria, and the safety technical specifications are discussed

  4. Space reactors - past, present, and future

    In the 1990s and beyond, advanced-design nuclear reactors could represent the prime source of both space power and propulsion. Many sophisticated military and civilian space missions of the future will require first kilowatt and then megawatt levels of power. This paper reviews key technology developments that accompanied past US space nuclear power development efforts, describes on-going programs, and then explores reactor technologies that will satisfy megawatt power level needs and beyond

  5. THE FUTURE OF SPACECRAFT NUCLEAR PROPULSION

    Jansen, Frank

    2014-01-01

    This paper summarizes the advantages of space nuclear power and propulsion systems. It describes the actual status of international power level dependent spacecraft nuclear propulsion missions, especially the high power EU-Russian MEGAHIT study including the Russian Megawatt-Class Nuclear Power Propulsion System, the NASA GRC project and the low and medium power EU DiPoP study. Space nuclear propulsion based mission scenarios of these studies are sketched as well.

  6. The Future of Spacecraft Nuclear Propulsion

    Jansen, F.

    2014-06-01

    This paper summarizes the advantages of space nuclear power and propulsion systems. It describes the actual status of international power level dependent spacecraft nuclear propulsion missions, especially the high power EU-Russian MEGAHIT study including the Russian Megawatt-Class Nuclear Power Propulsion System, the NASA GRC project and the low and medium power EU DiPoP study. Space nuclear propulsion based mission scenarios of these studies are sketched as well.

  7. Space Basics

    Herbert, Dexter (Editor)

    1991-01-01

    In this education video series, 'Liftoff to Learning', astronauts (Bruce Melnick, Thomas Akers, William Shepherd, Robert Cabana, and Richard Richards) describe the historical beginnings of space exploration from the time of Robert H. Goddard (considered the Father of Rocketry), who, in 1929, invented the first propellant rocket, the prototype of modern liquid propellant rockets, up to the modern Space Shuttles. The questions - where is space, what is space, and how do astronauts get to, stay in, and come back from space are answered through historical footage, computer graphics, and animation. The space environment effects, temperature effects, and gravitational effects on the launching, orbiting, and descent of the Shuttles are discussed. Included is historical still photos and film footage of past space programs and space vehicles.

  8. Space Curves

    Peskine, Christian; Sernesi, Edoardo

    1987-01-01

    The main topics of the conference on "Curves in Projective Space" were good and bad families of projective curves, postulation of projective space curves and classical problems in enumerative geometry.

  9. Nuclear Confidence

    2011-01-01

    The Fukushima nuclear accident provides valuable lessons for China national nuclear Corp.as it continues to expand its operations AS Japan’s Fukushima nuclear crisis sparks a global debate over nuclear safety,China National Nuclear Corp. (CNNC),the country’s largest nuclear plant operator, comes under the spotlight.

  10. To MARS and Beyond with Nuclear Power - Design Concept of Korea Advanced Nuclear Thermal Engine Rocket

    Nam, Seung Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The President Park of ROK has also expressed support for space program promotion, praising the success of NARO as evidence of a positive outlook. These events hint a strong signal that ROK's space program will be accelerated by the national eager desire. In this national eager desire for space program, the policymakers and the aerospace engineers need to pay attention to the advanced nuclear technology of ROK that is set to a major world nuclear energy country, even exporting the technology. The space nuclear application is a very much attractive option because its energy density is the most enormous among available energy sources in space. This paper presents the design concept of Korea Advanced Nuclear Thermal Engine Rocket (KANuTER) that is one of the advanced nuclear thermal rocket engine developing in Korea Advanced Institute of Science and Technology (KAIST) for space application. Solar system exploration relying on CRs suffers from long trip time and high cost. In this regard, nuclear propulsion is a very attractive option for that because of higher performance and already demonstrated technology. Although ROK was a late entrant into elite global space club, its prospect as a space racer is very bright because of the national eager desire and its advanced technology. Especially it is greatly meaningful that ROK has potential capability to launch its nuclear technology into space as a global nuclear energy leader and a soaring space adventurer. In this regard, KANuTER will be a kind of bridgehead for Korean space nuclear application.

  11. Time : space.

    M Crang

    2005-01-01

    Spaces of Geographical Thought examines key ideas like space and place - which inform the geographic imagination. The text: discusses the core conceptual vocabulary of human geography: agency: structure; state: society; culture: economy; space: place; black: white; man: woman; nature: culture; local: global; and time: space; explains the significance of these binaries in the constitution of geographic thought; and shows how many of these binaries have been interrogated and re-imagined in more...

  12. Space Microbiology

    Horneck, Gerda; Klaus, David M.; Mancinelli, Rocco L.

    2010-01-01

    Summary: The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotic...

  13. Space power station. Uchu hatsuden

    Kudo, I. (Electrotechnical Laboratory, Tsukuba (Japan))

    1993-02-20

    A calculation tells that the amount of electric power the world will use in the future will require 100 to 500 power plants each with an output of 5-GW class. If this conception is true, it is beyond dispute that utilizing nuclear power will constitute a core of the power generation even though the geographical conditions are severe for nuclear power plants. It is also certain that power generation using clean solar energy will play important roles if power supply stability can be achieved. This paper describes plans to develop space solar power generation and space nuclear power generation that can supply power solving problems concerning geographical conditions and power supply stability. The space solar power generation is a system to arrest solar energy on a static orbit. According to a result of discussions in the U.S.A., the plan calls for solar cell sheets spread over the surface of a structure with a size of 5 km [times] 10 km [times] 0.5 km thick, and electric power obtained therefrom is transmitted to a rectenna with a size of 10 km [times] 13 km, a receiving antenna on the ground. The space nuclear power generation will be constructed similarly on a static orbit. Researches on space nuclear reactors have already begun. 10 refs., 8 figs., 1 tab.

  14. Nuclear power and nuclear weapons

    The proliferation of nuclear weapons and the expanded use of nuclear energy for the production of electricity and other peaceful uses are compared. The difference in technologies associated with nuclear weapons and nuclear power plants are described

  15. Atomic power in space: A history

    ''Atomic Power in Space,'' a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. 19 figs., 3 tabs

  16. Koszul spaces

    Berglund, Alexander

    2014-01-01

    We prove that a nilpotent space is both formal and coformal if and only if it is rationally homotopy equivalent to the derived spatial realization of a graded commutative Koszul algebra. We call such spaces Koszul spaces and show that the rational homotopy groups and the rational homology of...... iterated loop spaces of Koszul spaces can be computed by applying certain Koszul duality constructions to the cohomology algebra. - See more at: http://www.ams.org/journals/tran/2014-366-09/S0002-9947-2014-05935-7/#sthash.hc29cqck.dpuf...

  17. Ideal spaces

    Väth, Martin

    1997-01-01

    Ideal spaces are a very general class of normed spaces of measurable functions, which includes e.g. Lebesgue and Orlicz spaces. Their most important application is in functional analysis in the theory of (usual and partial) integral and integro-differential equations. The book is a rather complete and self-contained introduction into the general theory of ideal spaces. Some emphasis is put on spaces of vector-valued functions and on the constructive viewpoint of the theory (without the axiom of choice). The reader should have basic knowledge in functional analysis and measure theory.

  18. Design spaces

    2005-01-01

    Digital technologies and media are becoming increasingly embodied and entangled in the spaces and places at work and at home. However, our material environment is more than a geometric abstractions of space: it contains familiar places, social arenas for human action. For designers, the integration...... of digital technology with space poses new challenges that call for new approaches. Creative alternatives to traditional systems methodologies are called for when designers use digital media to create new possibilities for action in space. Design Spaces explores how design and media art can provide...... creative alternatives for integrating digital technology with space. Connecting practical design work with conceptual development and theorizing, art with technology, and usesr-centered methods with social sciences, Design Spaces provides a useful research paradigm for designing ubiquitous computing. This...

  19. Reactors for nuclear electric propulsion

    Propulsion is the key to space exploitation and power is the key to propulsion. This paper examines the role of nuclear fission reactors as the primary power source for high specific impulse electric propulsion systems for space missions of the 1980s and 1990s. Particular mission applications include transfer to and a reusable orbital transfer vehicle from low-Earth orbit to geosynchronous orbit, outer planet exploration and reconnaissance missions, and as a versatile space tug supporting lunar resource development. Nuclear electric propulsion is examined as an indispensable component in space activities of the next two decades

  20. Nuclear Pulse Propulsion

    Atanas, Dilov; Hasan, Osman; Nickolai, Larsen; Tom, Edwards

    2015-01-01

    This project aims to provide the reader with a comprehensive insight into the potential of nuclear fuels to accelerate spacecraft propulsion, shorten journey times and broaden our exploration of space. The current methods of space propulsion offer little in the way of efficiency in terms of cost, time and henceforth investment and research. The dwindling resources of the planet plus the exponential rise of overpopulation will ultimately push us towards exploration of worlds further afield ...

  1. Nuclear Cryogenic Propulsion Stage

    Houts, Michael G.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2012-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced NEP.

  2. Three-dimensional PIC/MCC simulation of electron deposition in JAEA 10 A ion sources

    A systematic research on the electron deposition process in the JAEA 10 A ion source is carried out by using a particle-in-cell/Monte Carlo collision simulation, which is based on a full three-dimensional self-developed code. Two parts are studied. One is the space and energy distribution of fast and slow electrons, the other is the vibration excitation collisions between electrons and hydrogen moleculars. The results show that the inhomogeneity of electrons comes from the Y direction drift of the fast electrons (Te ≥ 25 eV) due to the action of the magnetic fields. This drift also increases the number of vibration excitation collisions in the —Y direction, and results in the increase of Ha in the —Y direction, eventually leading to the —Y drift of H−. It explains the spatial non-uniformity in the JAEA 10 A ion source. (physics of gases, plasmas, and electric discharges)

  3. Nuclear-pumped lasers

    Prelas, Mark

    2016-01-01

    This book focuses on Nuclear-Pumped Laser (NPL) technology and provides the reader with a fundamental understanding of NPLs, a review of research in the field, and exploration of large scale NPL system design and applications. Early chapters look at the fundamental properties of lasers, nuclear-pumping and nuclear reactions that may be used as drivers for nuclear-pumped lasers. The book goes on to explore the efficient transport of energy from the ionizing radiation to the laser medium and then the operational characteristics of existing nuclear-pumped lasers. Models based on Mathematica, explanations and a tutorial all assist the reader’s understanding of this technology. Later chapters consider the integration of the various systems involved in NPLs and the ways in which they can be used, including beyond the military agenda. As readers will discover, there are significant humanitarian applications for high energy/power lasers, such as deflecting asteroids, space propulsion, power transmission and mining....

  4. Space Commercialization

    Martin, Gary L.

    2011-01-01

    A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

  5. Space Age Spuds

    2000-01-01

    American Ag-Tech International, Ltd. developed a system called Quantum Tubers through the Wisconsin Center for Space Automation and Robotics (a NASA-sponsored Commercial Space Center). Using computerization and technologies originally intended for growing plants in space, the company developed a growth chamber that accelerates plant growth and is free of plant pathogens. The chamber is used to grow minitubers, which serve as nuclear seed stock for potatoes. Using lighting technology, temperature and humidity controls, and automation technology, the minituber can be generated in one closed facility with out much labor handling. This means they can be grown year round in extreme environments. The system eliminates the need for multiple generations of seed and eliminates exposure to pathogens, disease and pests. The Quantum Tubers system can produce 10-20 million tubers throughout the year, about equal to the world's supply of this generation seed stock.

  6. Phosphodiesterase 10A upregulation contributes to pulmonary vascular remodeling.

    Tian, Xia; Vroom, Christina; Ghofrani, Hossein Ardeschir; Weissmann, Norbert; Bieniek, Ewa; Grimminger, Friedrich; Seeger, Werner; Schermuly, Ralph Theo; Pullamsetti, Soni Savai

    2011-01-01

    Phosphodiesterases (PDEs) modulate the cellular proliferation involved in the pathophysiology of pulmonary hypertension (PH) by hydrolyzing cAMP and cGMP. The present study was designed to determine whether any of the recently identified PDEs (PDE7-PDE11) contribute to progressive pulmonary vascular remodeling in PH. All in vitro experiments were performed with lung tissue or pulmonary arterial smooth muscle cells (PASMCs) obtained from control rats or monocrotaline (MCT)-induced pulmonary hypertensive (MCT-PH) rats, and we examined the effects of the PDE10 inhibitor papaverine (Pap) and specific small interfering RNA (siRNA). In addition, papaverine was administrated to MCT-induced PH rats from day 21 to day 35 by continuous intravenous infusion to examine the in vivo effects of PDE10A inhibition. We found that PDE10A was predominantly present in the lung vasculature, and the mRNA, protein, and activity levels of PDE10A were all significantly increased in MCT PASMCs compared with control PASMCs. Papaverine and PDE10A siRNA induced an accumulation of intracellular cAMP, activated cAMP response element binding protein and attenuated PASMC proliferation. Intravenous infusion of papaverine in MCT-PH rats resulted in a 40%-50% attenuation of the effects on pulmonary hypertensive hemodynamic parameters and pulmonary vascular remodeling. The present study is the first to demonstrate a central role of PDE10A in progressive pulmonary vascular remodeling, and the results suggest a novel therapeutic approach for the treatment of PH. PMID:21494592

  7. T-REX: Thomson-Radiated Extreme X-rays Moving X-Ray Science into the ''Nuclear'' Applications Space with Thompson Scattered Photons

    Barty, C P; Hartemann, F V

    2004-09-21

    The scattering of laser photons from relativistic electrons (Thomson scattering) has been demonstrated to be a viable method for the production of ultrashort-duration pulses of tunable radiation in the 10-keV to 100-keV range. Photons in this range are capable of exciting or ionizing even the most tightly bound of atomic electrons. A wide variety of atomistic scale applications are possible. For example, Thomson x-ray sources have been constructed at LLNL (PLEIADES) and LBL as picosecond, stroboscopic probes of atomic-scale dynamics and at Vanderbilt University as element-specific tools for medical radiography and radiology. While these sources have demonstrated an attractive ability to simultaneously probe on an atomic spatial and temporal scale, they do not necessarily exploit the full potential of the Thomson scattering process to produce high-brightness, high-energy photons. In this white paper, we suggest that the peak brightness of Thomson sources can scale as fast as the 4th power of electron beam energy and that production via Thomson scattering of quasi-monochromatic, tunable radiation in the ''nuclear-range'' between 100-keV and several MeV is potentially a much more attractive application space for this process. Traditional sources in this regime are inherently ultra-broadband and decline rapidly in brightness as a function of photon energy. The output from dedicated, national-laboratory-scale, synchrotron facilities, e.g. APS, SPring8, ESRF etc., declines by more than 10 orders from 100 keV to 1 MeV. At 1 MeV, we conservatively estimate that Thomson-source, peak brightness can exceed that of APS (the best machine in the DOE complex) by more than 15 orders of magnitude. In much the same way that tunable lasers revolutionized atomic spectroscopy, this ''Peta-step'' advance in tunable, narrow-bandwidth, capability should enable entirely new fields of study and new, programmatically-interesting, applications such as

  8. Space debris

    Rossi, Alessandro

    2011-01-01

    Space debris are all man made objects including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that are non functional. This widely accepted official definition was adopted by the Inter-Agency Space Debris Coordination Committee (IADC), an international governmental forum for the worldwide coordination of activities related to the issues of man-made and natural debris in space.

  9. Morrey spaces

    Adams, David R

    2015-01-01

    In this set of lecture notes, the author includes some of the latest research on the theory of Morrey Spaces associated with Harmonic Analysis. There are three main claims concerning these spaces that are covered: determining the integrability classes of the trace of Riesz potentials of an arbitrary Morrey function; determining the dimensions of singular sets of weak solutions of PDE (e.g. The Meyers-Elcart System); and determining whether there are any “full” interpolation results for linear operators between Morrey spaces. This book will serve as a useful reference to graduate students and researchers interested in Potential Theory, Harmonic Analysis, PDE, and/or Morrey Space Theory. .

  10. Learning Spaces

    Falmagne, Jean-Claude

    2011-01-01

    Learning spaces offer a rigorous mathematical foundation for practical systems of educational technology. Learning spaces generalize partially ordered sets and are special cases of knowledge spaces. The various structures are investigated from the standpoints of combinatorial properties and stochastic processes. Leaning spaces have become the essential structures to be used in assessing students' competence of various topics. A practical example is offered by ALEKS, a Web-based, artificially intelligent assessment and learning system in mathematics and other scholarly fields. At the heart of A

  11. Nuclear works. Book of abstracts

    The interdisciplinary conference 'How can the social sciences help us understand the nuclear world?' seeks to reassess the relations between nuclear and social science research. It has two objectives. First, it seeks to take stock of and build on existing research by making explicit the theoretical approaches, the research methods, the difficulties met by researchers and by possibly identifying aspects of the nuclear phenomenon that may have been neglected or left out by existing research. Second, it wishes to question the relevance of social science to contemporary nuclear debates and policy making. The conference was organized in 6 sessions dealing with: 1 - Nuclear discourses - Contents and legitimacies: Nuclear terminology: from the dictionary to industrial practices (Danielle Candel, Marie Calberg-Challot), The problem of recognizing nuclear objects (Catherine Alexander), Demonstrating safety (Anne Bergsman, Morgan Meyer), Designing for nuclear safety, security and sustainability: a philosophical discourse of the nuclear reactor (Behnam Taebi, Jan Leen Kloosterman); 2 - History, time and space. Tropes of nuclear activity: The Gentilly-1 NPP history: a technological failure? (Mahdi Kelfaoui, Yves Gingras), Nuclear history: experience and research prospects (Leonard Laborie, Yves Bouvier, Alain Beltran), Temporality clash in front of radioactive wastes disposal (Laurence Raineau, Sophie Poirot-Delpech), Canadian nuclear from the standpoint of territoriality: how a NPP shapes space? (Franck Ollivon); 3 - Citizen mobilizations and the experience of disaster: 'We could make a moonscape out of the whole country...' Anti-Nuclear Activism at the Czech - Austrian Border (Birgit Mueller), From a catastrophe to the other: living with nuclear (Frederick Lemarchand), Nuclear contestation: between information, confrontation and political communication - 1970-2010 (Emmanuel Rivat); 4 - Social science meets the nuclear industry: Renegotiating repository safety: the history of

  12. Microcanonical simulation of nuclear multifragmentation

    We discuss the formal basis for the theoretical treatment of nuclear multifragmentation within a microcanonical framework. The important role played by highly excited nuclear states and the interfragment forces is illustrated. The requirement of detailed balance is especially discussed and illustrated for the fission-fusion Metropolis moves in configuration space. 13 refs., 2 figs

  13. Atomic Power in Space: A History

    1987-03-01

    "Atomic Power in Space," a history of the Space Isotope Power Program of the United States, covers the period from the program's inception in the mid-1950s through 1982. Written in non-technical language, the history is addressed to both the general public and those more specialized in nuclear and space technologies. Interplanetary space exploration successes and achievements have been made possible by this technology, for which there is no known substitue.

  14. Nuclear Medicine.

    Badawi, Ramsey D.

    2001-01-01

    Describes the use of nuclear medicine techniques in diagnosis and therapy. Describes instrumentation in diagnostic nuclear medicine and predicts future trends in nuclear medicine imaging technology. (Author/MM)

  15. Nuclear power

    Waller, David; McDonald, Alan; Greenwald, Judith; Mobbs, Paul

    2005-01-01

    David Waller and Alan McDonald ask whether a nuclear renaissance can be predicted; Judith M. Greenwald discusses keeping the nuclear power option open; Paul Mobbs considers the availability of uranium and the future of nuclear energy.

  16. Nuclear electronics

    A short survey is given on nuclear radiation detectors and nuclear electronics. It is written for newcomers and those, who are not very familiar with this technique. Some additional information is given on typical failures in nuclear measurement systems. (orig.)

  17. Space Telescope.

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  18. Space Microbiology

    Horneck, Gerda; Klaus, David M.; Mancinelli, Rocco L.

    2010-01-01

    Summary: The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis. PMID:20197502

  19. Performative Spaces

    Svaneklink, Annette

    2009-01-01

    can be related to traditional architectural concepts in terms of dealing with space, body, time and movement. The paper considers this performativity and dual spatiality as being a processual architecture, constantly reconfiguring new hybrids between space, image and user. This dual spatiality raises...

  20. Space psychology

    Parin, V. V.; Gorbov, F. D.; Kosmolinskiy, F. P.

    1974-01-01

    Psychological selection of astronauts considers mental responses and adaptation to the following space flight stress factors: (1) confinement in a small space; (2) changes in three dimensional orientation; (3) effects of altered gravity and weightlessness; (4) decrease in afferent nerve pulses; (5) a sensation of novelty and danger; and (6) a sense of separation from earth.