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Sample records for radioisotope generator based

  1. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2016-01-01

    High-efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRGs) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high-specific-power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTGs). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and the Department of Energy (DOE) called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered, which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provided about 50 to 450 W of direct current (DC) to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator, which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific

  2. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2015-01-01

    High efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRG) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high specific power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTG). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and DOE called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provide about 50 to 450 watts DC to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific power may be slightly lower than the ASRG and

  3. Milliwatt-Power Radioisotope Thermoelectric Generator (RTG) Based on Plutonium-238

    NASA Astrophysics Data System (ADS)

    Gusev, V. V.; Pustovalov, A. A.; Rybkin, N. N.; Anatychuk, L. I.; Demchuk, B. N.; Ludchak, I. Yu.

    2011-05-01

    Results of design and experimental studies aimed at developing a milliwatt-power radioisotope thermoelectric generator (RTG) based on plutonium-238 for space power are considered and analyzed. Milliwatt-power RTGs based on plutonium-238 are completely self-contained electric power sources offering a long proven service lifetime (>15 years) and high reliability. Such electric power sources find application both for space exploration and in terrestrial equipment, especially with the advance of microsystem technologies.

  4. Development of the data base for a degradation model of a selenide RTG. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Stapfer, G.; Truscello, V. C.

    1977-01-01

    The paper is concerned with the evaluation of the materials used in a selenide radioisotope thermoelectric generator (RTG). These materials are composed of n-type gadolinium selenide and n-type copper selenide. A three-fold evaluation approach is being used: (1) the study of the rate of change of the thermal conductivity of the material, (2) the investigation of the long-term stability of the material's Seebeck voltage and electrical resistivity under current and temperature gradient conditions, and (3) determination of the physical behavior and compatibility of the material with surrounding insulation at elevated temperatures. Programmatically, the third category of characteristic evaluation is being emphasized.

  5. Small radioisotope thermophotovoltaic (RTPV) generators

    NASA Astrophysics Data System (ADS)

    Schock, A.; Or, C.; Kumar, V.

    1996-02-01

    The National Aeronautics and Space Administration's recently inaugurated New Millennium program, with its emphasis on miniaturized spacecraft, has generated interest in a low-power (10- to 30-watt), low-mass, high-efficiency RTPV power system. This led to a Department of Energy (DOE)-sponsored design study by OSC (formerly Fairchild) personnel, who had previously conducted very encouraging studies of 75-watt RTPV systems based on two 250-watt General Purpose Heat Source (GPHS) modules. Since these modules were too large for the small RTPVs described in this paper, OSC generated derivative designs for 125-watt and 62.5-watt heat source modules. To minimize the need for new development and safety verification studies, these contained identical fuel pellets, clads, impact shell, and thermal insulation as the previously developed and safety-qualified 250-watt units. OSC also generated a novel heat source support scheme to reduce the heat losses through the structural supports, and a new and much simpler radiator structure, employing no honeycombs or heat pipes. OSC's previous RTPV study had been based on the use of GaSb PV cells and spectrally selective Infra-Red (IR) filters that had been partially developed and characterized by Boeing (now EDTEK) personnel. The present study was based on greatly improved selective filters developed and performance-mapped by EDTEK under an OSC-initiated subcontract. The paper describes illustrative small-RTPV designs and analyzes their mass, size, power output, system efficiency, and specific power, and illustrates their integration with a miniaturized New Millennium spacecraft.

  6. Safety monitoring system for radioisotope thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Zoltan, A.

    1973-01-01

    System alerts personnel of hazards which may develop while they are performing tests on radioisotope thermoelectric generator (RTG). Remedial action is initiated to minimize damage. Five operating conditions are monitored: hot junction temperature, cold junction temperature, thermal shroud coolant flow, vacuum in test chamber, and alpha radiation.

  7. Advanced Stirling Radioisotope Generator Life Certification Plan

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Zampino, Edward J.

    2013-01-01

    An Advanced Stirling Radioisotope Generator (ASRG) power supply is being developed by the Department of Energy (DOE) in partnership with NASA for potential future deep space science missions. Unlike previous radioisotope power supplies for space exploration, such as the passive MMRTG used recently on the Mars Curiosity rover, the ASRG is an active dynamic power supply with moving Stirling engine mechanical components. Due to the long life requirement of 17 years and the dynamic nature of the Stirling engine, the ASRG project faced some unique challenges trying to establish full confidence that the power supply will function reliably over the mission life. These unique challenges resulted in the development of an overall life certification plan that emphasizes long-term Stirling engine test and inspection when analysis is not practical. The ASRG life certification plan developed is described.

  8. High efficiency radioisotope thermophotovoltaic prototype generator

    NASA Astrophysics Data System (ADS)

    Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

    1995-10-01

    A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With

  9. High efficiency radioisotope thermophotovoltaic prototype generator

    NASA Technical Reports Server (NTRS)

    Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

    1995-01-01

    A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With

  10. Radioisotope thermoelectric generator transport trailer system

    NASA Astrophysics Data System (ADS)

    Ard, Kevin E.; King, David A.; Leigh, Harley; Satoh, Juli A.

    1995-01-01

    The Radioisotope Thermoelectric Generator (RTG) Transportation System, designated as System 100, comprises four major systems. The four major systems are designated as the Packaging System (System 120), Trailer System (System 140), Operations and Ancillary Equipment System (System 160), and Shipping and Receiving Facility Transport System (System 180). Packaging System (System 120), including the RTG packaging is licensed (regulatory) hardware; it is certified by the U.S. Department of Energy to be in accordance with Title 10, Code of Federal Regulations, Part 71 (10 CFR 71). System 140, System 160, and System 180 are nonlicensed (nonregulatory) hardware.

  11. Radioisotope thermoelectric generator transport trailer system

    SciTech Connect

    Ard, K.E.; King, D.A.; Leigh, H.; Satoh, J.A.

    1995-01-20

    The Radioisotope Thermoelectric Generator (RTG) Transportation System, designated as System 100, comprises four major systems. The four major systems are designated as the Packaging System (System 120), Trailer System (System 140), Operations and Ancillary Equipment System (System 160), and Shipping and Receiving Facility Transport System (System 180). Packaging System (System 120), including the RTG packaging is licensed (regulatory) hardware; it is certified by the U.S. Department of Energy to be in accordance with Title 10, {ital Code} {ital of} {ital Federal} {ital Regulations}, Part 71 (10 CFR 71). System 140, System 160, and System 180 are nonlicensed (nonregulatory) hardware. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}

  12. Cooling radioisotope thermoelectric generators in the Shuttle

    NASA Technical Reports Server (NTRS)

    Norman, R. M.

    1978-01-01

    Radioisotope thermoelectric generators (RTG) to be used on future spacecraft and launched by the Shuttle must be cooled from the time they are installed and enclosed until the spacecraft is deployed from the Shuttle. A special Cooling Kit maintains their temperature well below critical by circulating water through the coils soldered to them and through a heat exchanger that boils water and externally discharges the resulting steam. The RTG Cooling Kit, including its support frame, if fully charged with about 64 kg of evaporation water, will increase the Shuttle launch mass by about 200 kg.

  13. Radioisotope Thermoelectric Generators Based on Segmented BiTe/PbTe-BiTe/TAGS/PbSnTe

    NASA Astrophysics Data System (ADS)

    McAlonan, Malachy; Patel, Kalpesh; Cummer, Keith

    2006-01-01

    This paper reports on Phase 1 of a multifaceted effort to develop a more efficient radioisotope thermoelectric generator (RTG) for future NASA missions. The conversion efficiency goal is 10% or higher at a power level of 20 watt or higher. The thermoelectric (T/E) efficiency achievable with present T/E materials is about 8% for favorable temperatures. Thermoelectric converter designs, T/E material properties, and T/E couple thermal and electrical performance were investigated in Phase 1 of this program to find paths to improve conversion efficiency. T/E properties can be improved by optimizing the composition of the materials and by improving the micro structural characteristics such as homogeneity, grain size, and phases present. T/E couple performance can be improved by reducing the electrical and thermal contact resistances of the couple and within the segmented T/E elements. Performance and reliability improvements can be achieved by reducing the thermo-mechanical stresses, improving the quality of the bonds and interfaces, minimizing the number of required bonds, and reducing the degradation rates of both the T/E materials and the bonds. This paper focuses on one portion of the activity, i.e., the design of a small converter. In the converter design effort, a prototypic 20-watt device, suitable for use with a single general-purpose heat source (GPHS), was built using an optimized converter design of segmented thermoelectric elements of heritage composition. The 20-watt prototype achieved the power predicted for the test conditions. The chosen couple design used segmented BiTe/PbTe for the n-type element and BiTe/TAGS/PbSnTe, for the p-type T/E element. Use of the BiTe segment exploits the opportunity of the small RTG to operate at lower heat rejection temperatures and results in much higher conversion efficiency, the main objective of the NASA program. Long term data on similarly segmented couples at Teledyne together with the 20-watt module test results

  14. Analytical predictions of RTG power degradation. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Noon, E. L.; Raag, V.

    1979-01-01

    The DEGRA computer code that is based on a mathematical model which predicts performance and time-temperature dependent degradation of a radioisotope thermoelectric generator is discussed. The computer code has been used to predict performance and generator degradation for the selenide Ground Demonstration Unit (GDS-1) and the generator used in the Galileo Project. Results of parametric studies of load voltage vs generator output are examined as well as the I-V curve and the resulting predicted power vs voltage. The paper also discusses the increased capability features contained in DEGRA2 and future plans for expanding the computer code performance.

  15. Radioisotope thermoelectric generator reliability and safety

    SciTech Connect

    Campbell, R.; Klein, J.

    1989-01-01

    There are numerous occasions when a planetary mission requires energy in remote areas of the solar system. Anytime power is required much beyond Mars or the Asteroid Belts, solar power is not an option. The radioisotope thermoelectric generator (RTG) was developed for such a mission requirement. It is a relatively small and lightweight power source that can produce power under adverse conditions. Just this type of source has become the backbone of the power system for far outer plant exploration. Voyagers I and II are utilizing RTGs, which will soon power the Galileo spacecraft to Jupiter and the Ulysses spacecraft to study the solar poles. The paper discusses RTG operation including thermoelectric design, converter design, general-purpose heat source; RTG reliability including design, testing, experience, and launch approval; and RTG safety issues and methods of ensuring safety.

  16. Safe radioisotope thermoelectric generators and heat sources for space applications

    NASA Astrophysics Data System (ADS)

    O'Brien, R. C.; Ambrosi, R. M.; Bannister, N. P.; Howe, S. D.; Atkinson, H. V.

    2008-07-01

    Several isotopes are examined as alternatives to 238Pu that is traditionally used in radioisotope thermoelectric generators (RTGs) and heating units (RHUs). The radioisotopes discussed include 241Am, 208Po, 210Po, and 90Sr. The aim of this study is to facilitate the design of an RTG with a minimal radiation dose rate and mass including any required shielding. Applications of interest are primarily space and planetary exploration. In order to evaluate the properties of the alternative radioisotopes a Monte Carlo model was developed to examine the radiation protection aspect of the study. The thermodynamics of the power generation process is examined and possible materials for the housing and encapsulation of the radioisotopes are proposed. In this study we also present a historical review of radioisotope thermoelectric generators (RTGs) and the thermoelectric conversion mechanism in order to provide a direct comparison with the performance of our proposed alternative isotope systems.

  17. Development of Next Generation Segmented Thermoelectric Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Fleurial, J.; Caillat, T.; Ewell, R. C.

    2005-12-01

    Radioisotope thermoelectric generators have been used for space-based applications since 1961 with a total of 22 space missions that have successfully used RTGs for electrical power production. The key advantages of radioisotope thermoelectric generators (RTGs) are their long life, robustness, compact size, and high reliability. Thermoelectric converters are easily scalable, and possess a linear current-voltage curve, making power generation easy to control via a shunt regulator and shunt radiator. They produce no noise, vibration or torque during operation. These properties have made RTGs ideally suitable for autonomous missions in the extreme environments of outer space and on planetary surfaces. More advanced radioisotope power systems (RPS) with higher specific power (W/kg) and/or power output are desirable for future NASA missions, including the Europa Geophysical Orbiter mission. For the past few years, the Jet Propulsion Laboratory (JPL) has been developing more efficient thermoelectric materials and has demonstrated significant increases in the conversion efficiency of high temperature thermocouples, up to 14% when operated across a 975K to 300K temperature differential. In collaboration with NASA Glenn Research Center, universities (USC and UNM), Ceramic and Metal Composites Corporation and industrial partners, JPL is now planning to lead the research and development of advanced thermoelectric technology for integration into the next generations of RPS. Preliminary studies indicate that this technology has the potential for improving the RPS specific power by more than 50% over the current state-of-the-art multi-mission RTG being built for the Mars Science Laboratory mission. A second generation advanced RPS is projected at more than doubling the specific power.

  18. Development of a radioisotope heat source for the two-watt radioisotope thermoelectric generator

    NASA Astrophysics Data System (ADS)

    Howell, Edwin I.; McNeil, Dennis C.; Amos, Wayne R.

    1992-01-01

    Described is a radioisotope heat source for the Two-Watt Radioisotope Thermoelectric Generator (RTG) which is being considered for possible application by the U.S. Navy and for other Department of Defense applications. The heat source thermal energy (75 Wt) is produced from the alpha decay of plutonium-238 which is in the form of high-fired plutonium dioxide. The capsule is non-vented and consists of three domed cylindrical components each closed with a corresponding sealed end cap. Surrounding the fuel is the liner component, which is fabricated from a tantalum-based alloy, T-111. Also fabricated from T-111 is the next component, the strength member, which serves to meet pressure and impact criteria. The outermost component, or clad, is the oxidation- and corrosion-resistant nickel-based alloy, Hastelloy S. This paper defines the design considerations, details the hardware fabrication and welding processes, discusses the addition of yttrium to the fuel to reduce liner embrittlement, and describes the testing that has been conducted or is planned to assure that there is fuel containment not only during the heat source operational life, but also in case of an accident environment.

  19. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This presentation describes the capabilities of three-dimensional thermal power model of advanced stirling radioisotope generator (ASRG). The performance of the ASRG is presented for different scenario, such as Venus flyby with or without the auxiliary cooling system.

  20. A power conditioning system for radioisotope thermoelectric generator energy sources

    NASA Technical Reports Server (NTRS)

    Gillis, J. A., Jr.

    1974-01-01

    The use of radioisotope thermoelectric generators (RTG) as the primary source of energy in unmanned spacecraft is discussed. RTG output control, power conditioning system requirements, the electrical design, and circuit performance are also discussed.

  1. Parametric System Model for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.

    2015-01-01

    A Parametric System Model (PSM) was created in order to explore conceptual designs, the impact of component changes and power level on the performance of the Stirling Radioisotope Generator (SRG). Using the General Purpose Heat Source (GPHS approximately 250 Wth) modules as the thermal building block from which a SRG is conceptualized, trade studies are performed to understand the importance of individual component scaling on isotope usage. Mathematical relationships based on heat and power throughput, temperature, mass, and volume were developed for each of the required subsystems. The PSM uses these relationships to perform component- and system-level trades.

  2. Parametric System Model for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.

    2014-01-01

    A Parametric System Model (PSM) was created in order to explore conceptual designs, the impact of component changes and power level on the performance of Stirling Radioisotope Generator (SRG). Using the General Purpose Heat Source (GPHS approximately 250 watt thermal) modules as the thermal building block around which a SRG is conceptualized, trade studies are performed to understand the importance of individual component scaling on isotope usage. Mathematical relationships based on heat and power throughput, temperature, mass and volume were developed for each of the required subsystems. The PSM uses these relationships to perform component and system level trades.

  3. Characterization of the Advanced Stirling Radioisotope Generator Engineering Unit 2

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Niholas A.

    2016-01-01

    Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG) 140-W radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA Glenn Research Center recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's Advanced Stirling Convertor E3 (ASC-E3) Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth-generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included measurement of convertor, controller, and generator performance and efficiency; quantification of control authority of the controller; disturbance force measurement with varying piston phase and piston amplitude; and measurement of the effect of spacecraft direct current (DC) bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

  4. Characterization of the Advanced Stirling Radioisotope Generator EU2

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Oriti, Salvatore M.; Schifer, Nicholas A.

    2015-01-01

    Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-watt radioisotope power system. While the ASRG flight development project has ended, the hardware that was designed and built under the project is continuing to be tested to support future Stirling-based power system development. NASA GRC recently completed the assembly of the ASRG Engineering Unit 2 (EU2). The ASRG EU2 consists of the first pair of Sunpower's ASC-E3 Stirling convertors mounted in an aluminum housing, and Lockheed Martin's Engineering Development Unit (EDU) 4 controller (a fourth generation controller). The ASC-E3 convertors and Generator Housing Assembly (GHA) closely match the intended ASRG Qualification Unit flight design. A series of tests were conducted to characterize the EU2, its controller, and the convertors in the flight-like GHA. The GHA contained an argon cover gas for these tests. The tests included: measurement of convertor, controller, and generator performance and efficiency, quantification of control authority of the controller, disturbance force measurement with varying piston phase and piston amplitude, and measurement of the effect of spacecraft DC bus voltage on EU2 performance. The results of these tests are discussed and summarized, providing a basic understanding of EU2 characteristics and the performance and capability of the EDU 4 controller.

  5. Alpha-emitting radioisotopes for switchable neutron generators

    NASA Astrophysics Data System (ADS)

    Hertz, K. L.; Hilton, N. R.; Lund, J. C.; Van Scyoc, J. M.

    2003-06-01

    Traditionally, radioisotopic neutron generators mix an alpha-emitting radioisotope with beryllium. The disadvantage of such an alpha-Be source is that they emit neutrons at a steady rate even when stored. These conventional generators are extremely awkward to use in many applications because of the neutron shielding required to prevent exposure to personnel and sensitive electronics. Recently, at our laboratory and others, the possibility of using switchable radioactive neutron sources has been investigated. These sources rely on a mechanical operation to separate the alpha-emitting radioisotope from the Be target, thus allowing the source to be switched on and off. The utility of these new switchable sources is critically dependent on the selection of the alpha-emitting radioisotope. In this paper we discuss issues that determine the desirability of an alpha-emitting source for a switchable neutron generator, and select alpha emitters that are best suited for use in this application.

  6. Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission

    SciTech Connect

    Schock, Alfred

    1993-10-01

    The preceding paper described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Special Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to ~110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its engines fails. In fact, the latter system could deliver as much as 115 watts(e) if desired by the mission planners. There are 5 copies in the file.

  7. Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission

    NASA Astrophysics Data System (ADS)

    Schock, Alfred

    1994-07-01

    The preceding paper (Schock 1994) described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-Watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Special Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to -110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 Watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its two engines fails. In fact, the latter system could deliver as much as 115 Watts(e) if desired by the mission planners.

  8. Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission

    SciTech Connect

    Schock, Alfred

    2012-01-19

    The preceding paper described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Special Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to ~110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its engines fails. In fact, the latter system could deliver as much as 115 watts(e) if desired by the mission planners. There are 2 copies in the file.

  9. .sup.82 Sr-.sup.82 Rb Radioisotope generator

    DOEpatents

    Grant, Patrick M.; Erdal, Bruce R.; O'Brien, Harold A.

    1976-01-01

    An improved .sup.82 Sr-.sup.82 Rb radioisotope generator system, based upon the complexing ion exchange resin Chelex-100, has been developed. Columns of this material can be easily and rapidly milked, and the Rb-Sr separation factor for a fresh generator was found to be > 10.sup.7. Approximately 80 percent of the .sup.82 Rb present was delivered in a 15-ml volume of aqueous 0.2 M NH.sub.4 Cl solution. After more than 6 liters of eluant had been put through the generator, the Rb-Sr separation factor was still observed to be > 10.sup.5, and no unusual strontium breakthrough behavior was seen in the system over nearly three .sup.82 Sr half lives.

  10. Multi-Watt Small Radioisotope Thermoelectric Generator Conceptual Design Study

    NASA Astrophysics Data System (ADS)

    Determan, William R.; Otting, William; Frye, Patrick; Abelson, Robert; Ewell, Richard; Miyake, Bob; Synder, Jeff

    2007-01-01

    A need has been identified for a small, light-weight, reliable power source using a radioisotope heat source, to power the next generation of NASA's small surface rovers and exploration probes. Unit performance, development costs, and technical risk are key criteria to be used to select the best design approach. Because safety can be a major program cost and schedule driver, RTG designs should utilize the DOE radioisotope safety program's data base to the maximum extent possible. Other aspects important to the conceptual design include: 1) a multi-mission capable design for atmospheric and vacuum environments, 2) a module size based on one GPHS Step 2 module, 3) use of flight proven thermoelectric converter technologies, 4) a long service lifetime of up to 14 years, 5) maximize unit specific power consistent with all other requirements, and 6) be ready by 2013. Another critical aspect of the design is the thermal integration of the RTG with the rover or probe's heat rejection subsystem and the descent vehicle's heat rejection subsystem. This paper describes two multi-watt RTG design concepts and their integration with a MER-class rover.

  11. Investigation of Miniaturized Radioisotope Thermionic Power Generation for General Use

    NASA Technical Reports Server (NTRS)

    Duzik, Adam J.; Choi, Sang H.

    2016-01-01

    Radioisotope thermoelectric generators (RTGs) running off the radioisotope Pu238 are the current standard in deep space probe power supplies. While reliable, these generators are very inefficient, operating at only approx.7% efficiency. As an alternative, more efficient radioisotope thermionic emission generators (RTIGs) are being explored. Like RTGs, current RTIGs concepts use exotic materials for the emitter, limiting applicability to space and other niche applications. The high demand for long-lasting mobile power sources would be satisfied if RTIGs could be produced inexpensively. This work focuses on exposing several common materials, such as Al, stainless steel, W, Si, and Cu, to elevated temperatures under vacuum to determine the efficiency of each material as inexpensive replacements for thermoelectric materials.

  12. A facility to remotely assemble radioisotope thermoelectric generators

    SciTech Connect

    Engstrom, J.W.; Goldmann, L.H.; Truitt, R.W.

    1992-07-01

    Radioisotope Thermoelectric Generators (RTGs) are electrical power sources that use heat from decaying radioisotopes to directly generate electrical power. The RTG assembly process is performed in an inert atmosphere inside a large glovebox, which is surrounded by radiation shielding to reduce exposure to neutron and gamma radiation from the radioisotope heat source. In the past, allowable dose rate limits have allowed direct, manual assembly methods; however, current dose rate limits require a thicker radiation shielding that makes direct, manual assembly infeasible. To minimize RTG assembly process modifications, telerobotic systems are being investigated to perform remote assembly tasks. Telerobotic systems duplicate human arm motion and incorporate force feedback sensitivity to handle objects and tools in a human-like manner. A telerobotic system with two arms and a three-dimensional (3-D) vision system can be used to perform remote RTG assembly tasks inside gloveboxes and cells using unmodified, normal hand tools.

  13. A facility to remotely assemble radioisotope thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Engstrom, John W.; Goldmann, Louis H.; Truitt, Ross W.

    1993-01-01

    Radioisotope Thermoelectric Generators (RTGs) are electrical power sources that use heat from decaying radioisotopes to directly generate electrical power. The RTG assembly process is performed in an inert atmosphere inside a large glovebox, which is surrounded by radiation shielding to reduce exposure to neutron and gamma radiation from the radioisotope heat source. In the past, allowable dose rate limits have allowed direct, manual assembly methods; however, current dose rate limits require a thicker radiation shielding that makes direct, manual assembly infeasible. To minimize RTG assembly process modifications, telerobotic systems are being investigated to perform remote assembly tasks. Telerobotic systems duplicate human arm motion and incorporate force feedback sensitivity to handle objects and tools in a human-like manner. A telerobotic system with two arms and a three-dimensional (3-D) vision system can be used to perform remote RTG assembly tasks inside gloveboxes and cells using unmodified, normal hand tools.

  14. Direct charge radioisotope activation and power generation

    DOEpatents

    Lal, Amit; Li, Hui; Blanchard, James P.; Henderson, Douglass L.

    2002-01-01

    An activator has a base on which is mounted an elastically deformable micromechanical element that has a section that is free to be displaced toward the base. An absorber of radioactively emitted particles is formed on the base or the displaceable section of the deformable element and a source is formed on the other of the displaceable section or the base facing the absorber across a small gap. The radioactive source emits charged particles such as electrons, resulting in a buildup of charge on the absorber, drawing the absorber and source together and storing mechanical energy as the deformable element is bent. When the force between the absorber and the source is sufficient to bring the absorber into effective electrical contact with the source, discharge of the charge between the source and absorber allows the deformable element to spring back, releasing the mechanical energy stored in the element. An electrical generator such as a piezoelectric transducer may be secured to the deformable element to convert the released mechanical energy to electrical energy that can be used to provide power to electronic circuits.

  15. Procurement of a fully licensed radioisotope thermoelectric generator transportation system

    SciTech Connect

    Adkins, H.E.; Bearden, T.E.

    1990-10-01

    A fully licensed transportation system for Radioisotope Thermoelectric Generators and Light-Weight Radioisotope Heater Units is currently being designed and built. The system will comply with all applicable US Department of Transportation regulations without the use of a DOE Alternative.'' The US Department of Transportation has special double containment'' requirements for plutonium. The system packaging uses a doubly contained bell jar'' concept. A refrigerated trailer is used for cooling the high-heat payloads. The same packaging is used for both high- and low-heat payloads. The system is scheduled to be available for use by mid-1992. 4 refs., 4 figs., 2 tabs.

  16. Advanced Thermoelectric Materials for Radioisotope Thermoelectric Generators

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry; Hunag, C.-K.; Cheng, S.; Chi, S. C.; Gogna, P.; Paik, J.; Ravi, V.; Firdosy, S.; Ewell, R.

    2008-01-01

    This slide presentation reviews the progress and processes involved in creating new and advanced thermoelectric materials to be used in the design of new radioiootope thermoelectric generators (RTGs). In a program with Department of Energy, NASA is working to develop the next generation of RTGs, that will provide significant benefits for deep space missions that NASA will perform. These RTG's are planned to be capable of delivering up to 17% system efficiency and over 12 W/kg specific power. The thermoelectric materials being developed are an important step in this process.

  17. Method and system for radioisotope generation

    SciTech Connect

    Toth, James J.; Soderquist, Chuck Z.; Greenwood, Lawrence R.; Mattigod, Shas V.; Fryxell, Glen E.; O'Hara, Matthew J.

    2014-07-15

    A system and a process for producing selected isotopic daughter products from parent materials characterized by the steps of loading the parent material upon a sorbent having a functional group configured to selectively bind the parent material under designated conditions, generating the selected isotopic daughter products, and eluting said selected isotopic daughter products from the sorbent. In one embodiment, the process also includes the step of passing an eluent formed by the elution step through a second sorbent material that is configured to remove a preselected material from said eluent. In some applications a passage of the material through a third sorbent material after passage through the second sorbent material is also performed.

  18. Radioisotope thermoelectric generator transportation system subsystem 143 software development plan

    NASA Astrophysics Data System (ADS)

    King, D. A.

    1994-11-01

    This plan describes the activities to be performed and the controls to be applied to the process of specifying, developing, and qualifying the data acquisition software for the Radioisotope Thermoelectric Generator (RTG) Transportation System Subsystem 143 Instrumentation and Data Acquisition System (IDAS). This plan will serve as a software quality assurance plan, a verification and validation (V and V) plan, and a configuration management plan.

  19. Radioisotope thermoelectric generator transportation system subsystem 143 software development plan

    SciTech Connect

    King, D.A.

    1994-11-10

    This plan describes the activities to be performed and the controls to be applied to the process of specifying, developing, and qualifying the data acquisition software for the Radioisotope Thermoelectric Generator (RTG) Transportation System Subsystem 143 Instrumentation and Data Acquisition System (IDAS). This plan will serve as a software quality assurance plan, a verification and validation (V and V) plan, and a configuration management plan.

  20. Real-time monitoring during transportation of a radioisotope thermoelectric generator (RTG) using the radioisotope thermoelectric generator transportation system (RTGTS)

    SciTech Connect

    Pugh, B.K.

    1997-01-01

    The Radioisotopic Thermoelectric Generators (RTGs) that will be used to support the Cassini mission will be transported in the Radioisotope Thermoelectric Generator Transportation System (RTGTS). To ensure that the RTGs will not be affected during transportation, all parameters that could adversely affect RTG{close_quote}s performance must be monitored. The Instrumentation and Data Acquisition System (IDAS) for the RTGTS displays, monitors, and records all critical packaging and trailer system parameters. The IDAS also monitors the package temperature control system, RTG package shock and vibration data, and diesel fuel levels for the diesel fuel tanks. The IDAS alarms if any of these parameters reach an out-of-limit condition. This paper discusses the real-time monitoring during transportation of the Cassini RTGs using the RTGTS IDAS. {copyright} {ital 1997 American Institute of Physics.}

  1. Real-time monitoring during transportation of a radioisotope thermoelectric generator (RTG) using the radioisotope thermoelectric generator transportation system (RTGTS)

    NASA Astrophysics Data System (ADS)

    Pugh, Barry K.

    1997-01-01

    The Radioisotopic Thermoelectric Generators (RTGs) that will be used to support the Cassini mission will be transported in the Radioisotope Thermoelectric Generator Transportation System (RTGTS). To ensure that the RTGs will not be affected during transportation, all parameters that could adversely affect RTG's performance must be monitored. The Instrumentation and Data Acquisition System (IDAS) for the RTGTS displays, monitors, and records all critical packaging and trailer system parameters. The IDAS also monitors the package temperature control system, RTG package shock and vibration data, and diesel fuel levels for the diesel fuel tanks. The IDAS alarms if any of these parameters reach an out-of-limit condition. This paper discusses the real-time monitoring during transportation of the Cassini RTGs using the RTGTS IDAS.

  2. Real-time monitoring during transportation of a radioisotope thermoelectric generator (RTG) using the radioisotope thermoelectric generator transportation system (RTGTS)

    SciTech Connect

    Pugh, Barry K.

    1997-01-10

    The Radioisotopic Thermoelectric Generators (RTGs) that will be used to support the Cassini mission will be transported in the Radioisotope Thermoelectric Generator Transportation System (RTGTS). To ensure that the RTGs will not be affected during transportation, all parameters that could adversely affect RTG's performance must be monitored. The Instrumentation and Data Acquisition System (IDAS) for the RTGTS displays, monitors, and records all critical packaging and trailer system parameters. The IDAS also monitors the package temperature control system, RTG package shock and vibration data, and diesel fuel levels for the diesel fuel tanks. The IDAS alarms if any of these parameters reach an out-of-limit condition. This paper discusses the real-time monitoring during transportation of the Cassini RTGs using the RTGTS IDAS.

  3. Emitted radiation characteristics of plutonium dioxide radioisotope thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Gingo, P. J.; Steyn, J. J.

    1971-01-01

    The nuclear and emitted radiation characteristics of the radioisotope elements and impurities in commercial grade plutonium dioxide are presented in detail. The development of the methods of analysis are presented. Radioisotope thermoelectric generators (RTG) of 1575, 3468 and 5679 thermal watts are characterized with respect to neutron and gamma photon source strength as well as spatial and number flux distribution. The results are presented as a function of detector position and light element contamination concentration for fuel age ranging from 'fresh' to 18 years. The data may be used to obtain results for given O-18 and Pu-236 concentrations. The neutron and gamma photon flux and dose calculations compare favorably with reported experimental values for SNAP-27.

  4. Testing to Characterize the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward; Schreiber, Jeffrey

    2010-01-01

    The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. Lockheed Martin designed and fabricated an engineering unit (EU), the ASRG EU, under contract to the Department of Energy. This unit is currently undergoing extended operation testing at the NASA Glenn Research Center to generate performance data and validate life and reliability predictions for the generator and the Stirling convertors. It has also undergone performance tests to characterize generator operation while varying control parameters and system inputs. This paper summarizes and explains test results in the context of designing operating strategies for the generator during a space mission and notes expected differences between the EU performance and future generators.

  5. Development of Advanced Stirling Radioisotope Generator for Space Exploration

    NASA Astrophysics Data System (ADS)

    Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

    2007-01-01

    Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 We/kg to 7 We/kg, along with a 25% reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

  6. Development of Advanced Stirling Radioisotope Generator for Space Exploration

    NASA Technical Reports Server (NTRS)

    Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

    2007-01-01

    Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 to 7 We/kg, along with a 25 percent reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

  7. Rhenium-188--a generator-derived radioisotope for cancer therapy.

    PubMed

    Knapp, F F

    1998-10-01

    Rhenium-188 (188Re) is an important therapeutic radioisotope which is obtained on demand as carrier-free sodium perrhenate by saline elution of the tungsten-188/rhenium-188 generator system. With a half-life of 16.9 hours and emission of a high energy beta particle (maximal energy of 2.12 MeV) and a gamma photon (155 keV, 15%) for imaging, 188Re can be provided at reasonable costs for routine preparation of radiopharmaceuticals for cancer treatment. PMID:10851424

  8. An overview of the Radioisotope Thermoelectric Generator Transportation System Program

    SciTech Connect

    McCoy, J.C.; Becker, D.L.

    1996-03-01

    Radioisotope Thermoelectric Generators (RTG) convert the heat generated by radioactive decay to electricity using thermocouples. RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance once assembled and tested. These factors make RTGs particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71. The U.S. Department of Energy assigned the Radioisotope Thermoelectric Generator Transportation System (RTGTS) Program to Westinghouse Hanford Company in 1988 to develop a system meeting the regulatory requirements. The program objective was to develop a transportation system that would fully comply with 10 CFR 71 while protecting RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock and heat). The RTGTS is scheduled for completion in December 1996 and will be available to support the National Aeronautics and Space Administration{close_quote}s Cassini mission to Saturn in October 1997. This paper provides an overview of the RTGTS and discusses the hardware being produced. Additionally, various program management innovations mandated by recent major changes in the U.S. Department of Energy structure and resources will be outlined. {copyright} {ital 1996 American Institute of Physics.}

  9. An overview of the Radioisotope Thermoelectric Generator Transportation System Program

    NASA Astrophysics Data System (ADS)

    McCoy, John C.; Becker, David L.

    1996-03-01

    Radioisotope Thermoelectric Generators (RTG) convert the heat generated by radioactive decay to electricity using thermocouples. RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance once assembled and tested. These factors make RTGs particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71. The U.S. Department of Energy assigned the Radioisotope Thermoelectric Generator Transportation System (RTGTS) Program to Westinghouse Hanford Company in 1988 to develop a system meeting the regulatory requirements. The program objective was to develop a transportation system that would fully comply with 10 CFR 71 while protecting RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock and heat). The RTGTS is scheduled for completion in December 1996 and will be available to support the National Aeronautics and Space Administration's Cassini mission to Saturn in October 1997. This paper provides an overview of the RTGTS and discusses the hardware being produced. Additionally, various program management innovations mandated by recent major changes in the U.S. Department of Energy structure and resources will be outlined.

  10. GRC Supporting Technology for NASA's Advanced Stirling Radioisotope Generator (ASRG)

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2008-01-01

    From 1999 to 2006, the NASA Glenn Research Center (GRC) supported a NASA project to develop a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions. Lockheed Martin was selected as the System Integration Contractor for the SRG110, under contract to the Department of Energy (DOE). The potential applications included deep space missions, and Mars rovers. The project was redirected in 2006 to make use of the Advanced Stirling Convertor (ASC) that was being developed by Sunpower, Inc. under contract to GRC, which would reduce the mass of the generator and increase the power output. This change would approximately double the specific power and result in the Advanced Stirling Radioisotope Generator (ASRG). The SRG110 supporting technology effort at GRC was replanned to support the integration of the Sunpower convertor and the ASRG. This paper describes the ASRG supporting technology effort at GRC and provides details of the contributions in some of the key areas. The GRC tasks include convertor extended-operation testing in air and in thermal vacuum environments, heater head life assessment, materials studies, permanent magnet characterization and aging tests, structural dynamics testing, electromagnetic interference and electromagnetic compatibility characterization, evaluation of organic materials, reliability studies, and analysis to support controller development.

  11. An overview of the Radioisotope Thermoelectric Generator Transporation System Program

    SciTech Connect

    McCoy, J.C.

    1995-10-01

    Radioisotope Thermoelectric Generators (RTG) convert the heat generated by radioactive decay to electricity using thermocouples. RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance once assembled and tested. These factors make RTGs particularly attractive for use in spacecraft However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71. The US Department of Energy assigned the Radioisotope Thermoelectric Generator Transportation System (RTGTS) Program to Westinghouse Hanford Company in 1988 to develop a system meeting the regulatory requirements. The program objective was to develop a transportation system that would fully comply with 10 CFR 71 while protecting RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock and heat). The RTGTS is scheduled for completion in December 1996 and will be available to support the National Aeronautics and Space Administrations Cassini mission to Saturn in October 1997. This paper provides an overview of the RTGTS and discusses the hardware being produced. Additionally, various program management innovations mandated by recent ma or changes in the US Department of Energy structure and resources will be outlined.

  12. RTGs - The powering of Ulysses. [Radio-isotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Mastal, E. F.; Campbell, R. W.

    1990-01-01

    The radio-isotope thermoelectric generator (RTG) for Ulysses' electronic supply is described noting that lack of sufficient sunlight renders usual solar cell power generation ineffective due to increased distance from sun. The history of the RTG in the U.S.A. is reviewed citing the first RTG launch in 1961 with an electrical output of 2.7 W and the improved Ulysses RTG, which provides 285 W at mission beginning and 250 W at mission end. The RTG concept is discussed including the most recent RTG technology developed by the DOE, the General Purpose Heat Source RTG (GPHS-RTG). The system relies upon heat generated by radioactive decay using radioactive plutonium-238, which is converted directly to energy using the Seebeck method.

  13. Computer program for the transient analysis of radioisotope thermoelectric generators.

    NASA Technical Reports Server (NTRS)

    Eggers, P. E.; Ridihalgh, J. L.

    1972-01-01

    A computer program is described which represents a comprehensive analytical tool providing the capability for predicting the output power and temperature profile of an arbitrary radioisotope thermoelectric generator (RTG) design in the presence of time-dependent operating conditions. The approach taken involves the merging of three existing computer programs - namely, an RTG weight optimization design program, a thermoelectric analysis program, and a nodal heat-transfer computer program. A total of seven transient conditions are included in the computer program as the principal transients affecting long- and short-term performance characteristics of RTGs. This computer program is unique in that it designs an optimum RTG, generates a thermal model or analog and performs heat-transfer analysis of the RTG under user-specified transient conditions.

  14. Using SpaceClaim/TD Direct for Modeling Components with Complex Geometries for the Thermal Desktop-Based Advanced Stirling Radioisotope Generator Model

    NASA Technical Reports Server (NTRS)

    Fabanich, William

    2014-01-01

    SpaceClaim/TD Direct has been used extensively in the development of the Advanced Stirling Radioisotope Generator (ASRG) thermal model. This paper outlines the workflow for that aspect of the task and includes proposed best practices and lessons learned. The ASRG thermal model was developed to predict component temperatures and power output and to provide insight into the prime contractors thermal modeling efforts. The insulation blocks, heat collectors, and cold side adapter flanges (CSAFs) were modeled with this approach. The model was constructed using mostly TD finite difference (FD) surfaces solids. However, some complex geometry could not be reproduced with TD primitives while maintaining the desired degree of geometric fidelity. Using SpaceClaim permitted the import of original CAD files and enabled the defeaturing repair of those geometries. TD Direct (a SpaceClaim add-on from CRTech) adds features that allowed the mark-up of that geometry. These so-called mark-ups control how finite element (FE) meshes were generated and allowed the tagging of features (e.g. edges, solids, surfaces). These tags represent parameters that include: submodels, material properties, material orienters, optical properties, and radiation analysis groups. TD aliases were used for most tags to allow analysis to be performed with a variety of parameter values. Domain-tags were also attached to individual and groups of surfaces and solids to allow them to be used later within TD to populate objects like, for example, heaters and contactors. These tools allow the user to make changes to the geometry in SpaceClaim and then easily synchronize the mesh in TD without having to redefine these objects each time as one would if using TD Mesher.The use of SpaceClaim/TD Direct has helped simplify the process for importing existing geometries and in the creation of high fidelity FE meshes to represent complex parts. It has also saved time and effort in the subsequent analysis.

  15. Using SpaceClaimTD Direct for Modeling Components with Complex Geometries for the Thermal Desktop-Based Advanced Stirling Radioisotope Generator Model

    NASA Technical Reports Server (NTRS)

    Fabanich, William A., Jr.

    2014-01-01

    SpaceClaim/TD Direct has been used extensively in the development of the Advanced Stirling Radioisotope Generator (ASRG) thermal model. This paper outlines the workflow for that aspect of the task and includes proposed best practices and lessons learned. The ASRG thermal model was developed to predict component temperatures and power output and to provide insight into the prime contractor's thermal modeling efforts. The insulation blocks, heat collectors, and cold side adapter flanges (CSAFs) were modeled with this approach. The model was constructed using mostly TD finite difference (FD) surfaces/solids. However, some complex geometry could not be reproduced with TD primitives while maintaining the desired degree of geometric fidelity. Using SpaceClaim permitted the import of original CAD files and enabled the defeaturing/repair of those geometries. TD Direct (a SpaceClaim add-on from CRTech) adds features that allowed the "mark-up" of that geometry. These so-called "mark-ups" control how finite element (FE) meshes are to be generated through the "tagging" of features (e.g. edges, solids, surfaces). These tags represent parameters that include: submodels, material properties, material orienters, optical properties, and radiation analysis groups. TD aliases were used for most tags to allow analysis to be performed with a variety of parameter values. "Domain-tags" were also attached to individual and groups of surfaces and solids to allow them to be used later within TD to populate objects like, for example, heaters and contactors. These tools allow the user to make changes to the geometry in SpaceClaim and then easily synchronize the mesh in TD without having to redefine the objects each time as one would if using TDMesher. The use of SpaceClaim/TD Direct helps simplify the process for importing existing geometries and in the creation of high fidelity FE meshes to represent complex parts. It also saves time and effort in the subsequent analysis.

  16. Stirling Convertor Technologies Being Developed for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.

    2003-01-01

    The Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and the NASA Glenn Research Center are developing a high-efficiency Stirling Radioisotope Generator (SRG) for NASA space science missions. The SRG is being developed for multimission use, including providing electric power for unmanned Mars rovers and deep space missions. On Mars, rovers with SRGs would be used for missions that might not be able to use photovoltaic power systems, such as exploration at high Martian latitudes and missions of long duration. The projected SRG system efficiency of 23 percent will reduce the required amount of radioisotope by a factor of 4 or more in comparison to currently used Radioisotope Thermoelectric Generators. The Department of Energy recently named Lockheed Martin as the system integration contractor. Lockheed Martin has begun to develop the SRG engineering unit under contract to the Department of Energy, and has contract options to develop the qualification unit and the first flight units. The developers expect the SRG to produce about 114 Wdc at the beginning of mission, using two opposed Stirling convertors and two General Purpose Heat Source modules. STC previously developed the Stirling convertor under contract to the Department of Energy and is now providing further development as a subcontractor to Lockheed Martin. Glenn is conducting an in-house technology project to assist in developing the convertor for space qualification and mission implementation. A key milestone was recently reached with the accumulation of 12 000 hr of long-term aging on two types of neodymium-iron boron permanent magnets. These tests are characterizing any possible aging in the strength or demagnetization resistance of the magnets used in the linear alternator. Preparations are underway for a thermal/vacuum system demonstration and unattended operation during endurance testing of the 55-We Technology Demonstration Convertors. In addition, Glenn is developing a

  17. Reliability Demonstration Approach for Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Ha, CHuong; Zampino, Edward; Penswick, Barry; Spronz, Michael

    2010-01-01

    Developed for future space missions as a high-efficiency power system, the Advanced Stirling Radioisotope Generator (ASRG) has a design life requirement of 14 yr in space following a potential storage of 3 yr after fueling. In general, the demonstration of long-life dynamic systems remains difficult in part due to the perception that the wearout of moving parts cannot be minimized, and associated failures are unpredictable. This paper shows a combination of systematic analytical methods, extensive experience gained from technology development, and well-planned tests can be used to ensure a high level reliability of ASRG. With this approach, all potential risks from each life phase of the system are evaluated and the mitigation adequately addressed. This paper also provides a summary of important test results obtained to date for ASRG and the planned effort for system-level extended operation.

  18. End-on radioisotope thermoelectric generator impact tests

    NASA Astrophysics Data System (ADS)

    Reimus, M. A. H.; Hinckley, J. E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  19. End-on radioisotope thermoelectric generator impact tests

    SciTech Connect

    Reimus, M.A.; Hinckley, J.E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure. {copyright} {ital 1997 American Institute of Physics.}

  20. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M. A. H.; Hinckley, J. E.

    1998-01-15

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  1. Radioisotope thermoelectric generator/thin fragment impact test

    NASA Astrophysics Data System (ADS)

    Reimus, M. A. H.; Hinckley, J. E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  2. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.; Hinckley, J.E.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel. {copyright} {ital 1998 American Institute of Physics.}

  3. Radioisotope thermoelectric generator cooling in the Shuttle bay

    NASA Technical Reports Server (NTRS)

    Stimpson, L. D.; Levine, D. I.

    1979-01-01

    The paper describes a Shuttle-integrated radioisotope thermoelectric generator (RTG) that consists primarily of a pump package and plumbing connected directly to the Shuttle payload heat exchanger. The RTG utilizes on-board water evaporative cooling capability, which is normally used for ascent, entry, and for supplementing the radiators. Attention is given to the RTG cooling concepts which include: (1) an active thermal cooling system (ATCS), where two Freon-21 loops operate simultaneously to transport heat from the Orbiter subsystem and payloads through liquid-to-liquid heat exchangers and pin-fin coldplates to four heat sinks, and (2) an atmosphere revitalization system (ARS) which provides for thermal, pressure, and contaminate control of the crew cabin and its equipment. The use of a payload heat exchanger to reduce weight, cost and complexity associated with an independent cooling system was investigated in detail.

  4. Development and Buildup of a Stirling Radioisotope Generator Electrical Simulator

    NASA Technical Reports Server (NTRS)

    Prokop, Norman F.; Krasowski, Michael J.; Greer, Lawrence C.; Flatico, Joseph M.; Spina, Dan C.

    2008-01-01

    This paper describes the development of a Stirling Radioisotope Generator (SRG) Simulator for use in a prototype lunar robotic rover. The SRG developed at NASA Glenn Research Center (GRC) is a promising power source for the robotic exploration of the sunless areas of the moon. The simulator designed provides a power output similar to the SRG output of 5.7 A at 28 Vdc, while using ac wall power as the input power source. The designed electrical simulator provides rover developers the physical and electrical constraints of the SRG supporting parallel development of the SRG and rover. Parallel development allows the rover design team to embrace the SRG s unique constraints while development of the SRG is continued to a flight qualified version.

  5. Radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system (PMS). The results of this test indicated that impact of the RTG by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the convertor housing, failure of one fueled clad, and release of a small quantity of fuel.

  6. End-on radioisotope thermoelectric generator impact tests

    SciTech Connect

    Reimus, M.A.H.; Hhinckley, J.E.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of [sup 238]Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). The modular GPHS design was developed to address both survivability during launch abort and return from orbit. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  7. Test Program for Stirling Radioisotope Generator Hardware at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Bolotin, Gary S.; Oriti, Salvatore M.

    2014-01-01

    Stirling-based energy conversion technology has demonstrated the potential of high efficiency and low mass power systems for future space missions. This capability is beneficial, if not essential, to making certain deep space missions possible. Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-watt radioisotope power system. A variety of flight-like hardware, including Stirling convertors, controllers, and housings, was designed and built under the ASRG flight development project. To support future Stirling-based power system development NASA has proposals that, if funded, will allow this hardware to go on test at the NASA Glenn Research Center (GRC). While future flight hardware may not be identical to the hardware developed under the ASRG flight development project, many components will likely be similar, and system architectures may have heritage to ASRG. Thus the importance of testing the ASRG hardware to the development of future Stirling-based power systems cannot be understated. This proposed testing will include performance testing, extended operation to establish an extensive reliability database, and characterization testing to quantify subsystem and system performance and better understand system interfaces. This paper details this proposed test program for Stirling radioisotope generator hardware at NASA GRC. It explains the rationale behind the proposed tests and how these tests will meet the stated objectives.

  8. Test Program for Stirling Radioisotope Generator Hardware at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Bolotin, Gary S.; Oriti, Salvatore M.

    2015-01-01

    Stirling-based energy conversion technology has demonstrated the potential of high efficiency and low mass power systems for future space missions. This capability is beneficial, if not essential, to making certain deep space missions possible. Significant progress was made developing the Advanced Stirling Radioisotope Generator (ASRG), a 140-W radioisotope power system. A variety of flight-like hardware, including Stirling convertors, controllers, and housings, was designed and built under the ASRG flight development project. To support future Stirling-based power system development NASA has proposals that, if funded, will allow this hardware to go on test at the NASA Glenn Research Center. While future flight hardware may not be identical to the hardware developed under the ASRG flight development project, many components will likely be similar, and system architectures may have heritage to ASRG. Thus, the importance of testing the ASRG hardware to the development of future Stirling-based power systems cannot be understated. This proposed testing will include performance testing, extended operation to establish an extensive reliability database, and characterization testing to quantify subsystem and system performance and better understand system interfaces. This paper details this proposed test program for Stirling radioisotope generator hardware at NASA Glenn. It explains the rationale behind the proposed tests and how these tests will meet the stated objectives.

  9. Environmental, health and safety assessment of decommissioning radioisotope thermoelectric generators (RTGs) in northwest Russia.

    PubMed

    Standring, W J F; Dowdall, M; Sneve, M; Selnaes, Ø G; Amundsen, I

    2007-09-01

    This paper presents findings from public health and environmental assessment work that has been conducted as part of a joint Norwegian-Russian project to decommission radioisotope thermoelectric generators (RTG) in northwest Russia. RTGs utilise heat energy from radioactive isotopes, in this case 90Sr and its daughter nuclide 90Y, to generate electricity as a power source. Different accident scenarios based on the decommissioning process for RTGs are assessed in terms of possible radiation effects to humans and the environment. Doses to humans and biota under the worst-case scenario were lower than threshold limits given in ICRP and IAEA literature. PMID:17768331

  10. Thermal vacuum life test facility for radioisotope thermoelectric generators

    SciTech Connect

    Deaton, R.L.; Goebel, C.J.; Amos, W.R.

    1990-01-01

    In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al. (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met. 4 refs., 3 figs.

  11. Analytical thermal model validation for Cassini radioisotope thermoelectric generator

    SciTech Connect

    Lin, E.I.

    1997-12-31

    The Saturn-bound Cassini spacecraft is designed to rely, without precedent, on the waste heat from its three radioisotope thermoelectric generators (RTGs) to warm the propulsion module subsystem, and the RTG end dome temperature is a key determining factor of the amount of waste heat delivered. A previously validated SINDA thermal model of the RTG was the sole guide to understanding its complex thermal behavior, but displayed large discrepancies against some initial thermal development test data. A careful revalidation effort led to significant modifications and adjustments of the model, which result in a doubling of the radiative heat transfer from the heat source support assemblies to the end domes and bring up the end dome and flange temperature predictions to within 2 C of the pertinent test data. The increased inboard end dome temperature has a considerable impact on thermal control of the spacecraft central body. The validation process offers an example of physically-driven analytical model calibration with test data from not only an electrical simulator but also a nuclear-fueled flight unit, and has established the end dome temperatures of a flight RTG where no in-flight or ground-test data existed before.

  12. Thermal vacuum life test facility for radioisotope thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Deaton, R. L.; Goebel, C. J.; Amos, W. R.

    In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG and G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al., (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met.

  13. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This paper presents recent thermal model results of the Advanced Stirling Radioisotope Generator (ASRG). The three-dimensional (3D) ASRG thermal power model was built using the Thermal Desktop(trademark) thermal analyzer. The model was correlated with ASRG engineering unit test data and ASRG flight unit predictions from Lockheed Martin's (LM's) I-deas(trademark) TMG thermal model. The auxiliary cooling system (ACS) of the ASRG is also included in the ASRG thermal model. The ACS is designed to remove waste heat from the ASRG so that it can be used to heat spacecraft components. The performance of the ACS is reported under nominal conditions and during a Venus flyby scenario. The results for the nominal case are validated with data from Lockheed Martin. Transient thermal analysis results of ASRG for a Venus flyby with a representative trajectory are also presented. In addition, model results of an ASRG mounted on a Cassini-like spacecraft with a sunshade are presented to show a way to mitigate the high temperatures of a Venus flyby. It was predicted that the sunshade can lower the temperature of the ASRG alternator by 20 C for the representative Venus flyby trajectory. The 3D model also was modified to predict generator performance after a single Advanced Stirling Convertor failure. The geometry of the Microtherm HT insulation block on the outboard side was modified to match deformation and shrinkage observed during testing of a prototypic ASRG test fixture by LM. Test conditions and test data were used to correlate the model by adjusting the thermal conductivity of the deformed insulation to match the post-heat-dump steady state temperatures. Results for these conditions showed that the performance of the still-functioning inboard ACS was unaffected.

  14. Environmental assessment of decommissioning radioisotope thermoelectric generators (RTG) in northwest Russia

    SciTech Connect

    Hosseini, A.; Standring, W.J.F.; Brown, J.E.; Dowdall, M.; Amundsen, I.B.

    2007-07-01

    This article presents some results from assessment work conducted as part of a joint Norwegian-Russian project to decommission radioisotope thermoelectric generators (RTG) in Northwest Russia. Potential worst case accident scenarios, based on the decommissioning procedures for RTGs, were assessed to study possible radiation effects to the environment. Close contact with exposed RTG sources will result in detrimental health effects. However, doses to marine biota from ingestion of radioactivity under the worst-case marine scenario studied were lower than threshold limits given in IAEA literature. (authors)

  15. Development of a Power Electronics Controller for the Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Leland, Douglas K.; Priest, Joel F.; Keiter, Douglas E.; Schreiber, Jeffrey G.

    2008-01-01

    Under a U.S. Department of Energy program for radioisotope power systems, Lockheed Martin is developing an Engineering Unit of the Advanced Stirling Radioisotope Generator (ASRG). This is an advanced version of the previously reported SRG110 generator. The ASRG uses Advanced Stirling Convertors (ASCs) developed by Sunpower Incorporated under a NASA Research Announcement contract. The ASRG makes use of a Stirling controller based on power electronics that eliminates the tuning capacitors. The power electronics controller synchronizes dual-opposed convertors and maintains a fixed frequency operating point. The controller is single-fault tolerant and uses high-frequency pulse width modulation to create the sinusoidal currents that are nearly in phase with the piston velocity, eliminating the need for large series tuning capacitors. Sunpower supports this effort through an extension of their controller development intended for other applications. Glenn Research Center (GRC) supports this effort through system dynamic modeling, analysis and test support. The ASRG design arrived at a new baseline based on a system-level trade study and extensive feedback from mission planners on the necessity of single-fault tolerance. This paper presents the baseline design with an emphasis on the power electronics controller detailed design concept that will meet space mission requirements including single fault tolerance.

  16. Advanced Subcritical Assistance Radioisotope Thermoelectric Generator: An Imperative Solution for the Future of NASA Exploration

    NASA Astrophysics Data System (ADS)

    Arias, F. J.

    A new generation of radioisotope thermoelectrical generator is proposed for very long space exploration missions. The Advanced Subcritical Assistance Radioisotope Thermoelectric Generator (ASA-RTG) amplify the power from natural decay of pu-238 by a small subcritical multiplication produced from the small neutron background generated from (α, n) reactions between the α particles from Pu-238 and beryllium, lithium or other low-Z isotope, extracting the maximum advantage and performance from the precious α disintegration, and then of the very scarce pu-238. The process is self controlled by the natural decay of Pu-238 with the progressive reduction of the power output (RTG) and additionally and simultaneously compensate by the natural decay of a neutronic poisson which increase simultaneously the subcritical multiplication resulting in a contrary effect, i.e., causing an increase in the power. ASA-RTG is not in conflict with previous RTG, and could fit within the type of Radioisotope Thermoelectric Generator developed for NASA space missions as the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and the Advanced Stirling Radioisotope Generator (ASRG).

  17. Increasing the Efficiency of the Multi-mission Radioisotope Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Holgate, Tim C.; Bennett, Russell; Hammel, Tom; Caillat, Thierry; Keyser, Steve; Sievers, Bob

    2015-06-01

    The National Aeronautics and Space Administration's Mars Science Laboratory terrestrial rover, Curiosity, has recently completed its first Martian year (687 Earth days) during which it has provided a wealth of information and insight into the red planet's atmosphere and geology. The success of this mission was made possible in part by the reliable electrical power provided by its onboard thermoelectric power source—the multi-mission radioisotope thermoelectric generator (MMRTG). In an effort to increase the output power and efficiency of these generators, a newly designed enhanced MMRTG (eMMRTG) that will utilize the more efficient skutterudite-based thermoelectric materials has been conceptualized and modeled, and is now being developed. A discussion of the motivations, modeling results and key design factors are presented and discussed.

  18. Radioisotope Thermophotovoltaic (RTPV) Generator and Its Application to the Pluto Fast Flyby Mission

    SciTech Connect

    Schock, Alfred; Mukunda, Meera; Or, Chuen T; Kumar, Vasanth; Summers, G.

    1994-01-16

    This paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator. Instead of conducting a generic study, it was decided to focus the design by directing it at a specific space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a one-year post-encounter cruise. Because of Pluto's long distance from the sun (30-50 A.U.) and the mission's large energy demand, JPL has baselined the use of a radioisotope power system for the PFF spacecraft. The chief advantage of Radioisotope Thermophotovoltaic (RTPV) power systems over current Radioisotope Thermoelectric Generators (RTGs) is their much higher conversion efficiency, which greatly reduces the mass and cost of the required radioisotope heat source. Those attributes are particularly important for the PFF mission, which - like all NASA missions under current consideration - is severely mass- and cost-limited. The paper describes the design of the radioisotope heat source, the thermophotovoltaic converter, and the heat rejection system; and presents the results of the thermal, electrical, and structural analysis and the design optimization of the integrated RTPV system. It briefly summarizes the RTPV system's current technology status, and lists a number of factors that my greatly reduce the need for long-term tests to demonstrate generator lifetime. Our analytical results show very substantial performance improvements over an RTG designed for the same mission, and suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the PFF mission but also for other future missions requiring small, long-lived, low

  19. [Radioisotope thermoelectric generators and ancillary activities]. Monthly technical progress report, 1 April--28 April 1996

    SciTech Connect

    1996-06-01

    Tehnical progress achieved during this period on radioisotope thermoelectric generators is described under the following tasks: engineering support, safety analysis, qualified unicouple fabrication, ETG fabrication/assembly/test, RTG shipping/launch support, design/review/mission applications, and project management/quality assurance/reliability.

  20. Thermal Analysis of Step 2 GPHS for Next Generation Radioisotope Power Source Missions

    NASA Astrophysics Data System (ADS)

    Pantano, David R.; Hill, Dennis H.

    2005-02-01

    The Step 2 General Purpose Heat Source (GPHS) is a slightly larger and more robust version of the heritage GPHS modules flown on previous Radioisotope Thermoelectric Generator (RTG) missions like Galileo, Ulysses, and Cassini. The Step 2 GPHS is to be used in future small radioisotope power sources, such as the Stirling Radioisotope Generator (SRG110) and the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). New features include an additional central web of Fine Weave Pierced Fabric (FWPF) graphite in the aeroshell between the two Graphite Impact Shells (GIS) to improve accidental reentry and impact survivability and an additional 0.1-inch of thickness to the aeroshell broad faces to improve ablation protection. This paper details the creation of the thermal model using Thermal Desktop and AutoCAD interfaces and provides comparisons of the model to results of previous thermal analysis models of the heritage GPHS. The results of the analysis show an anticipated decrease in total thermal gradient from the aeroshell to the iridium clads compared to the heritage results. In addition, the Step 2 thermal model is investigated under typical SRG110 boundary conditions, with cover gas and gravity environments included where applicable, to provide preliminary guidance for design of the generator. Results show that the temperatures of the components inside the GPHS remain within accepted design limits during all envisioned mission phases.

  1. Pyroshock Testing of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG)

    NASA Technical Reports Server (NTRS)

    Woerner, David; Fleurial, Jean-Pierre; Bennett, Russell; Hammel, Tom; Otting, William

    2013-01-01

    The Mars Science Laboratory (MSL) Multi-Mission Radioisotope Thermoelectric Generator, or MMRTG, was developed by the Department Of Energy to a set of requirements from multiple NASA mission concepts. Those concepts included deep space missions to the outer planets as well as missions to Mars. The synthesis of that diverse set of requirements addressed functional as well as environmental requirements.

  2. Specification for strontium-90 500-watt(e) radioisotopic thermoelectric generator

    NASA Astrophysics Data System (ADS)

    Hammel, T.; Himes, J.; Lieberman, A.; McGrew, J. W.; Owings, D.; Schumann, F.

    1983-04-01

    A conceptual design for a demonstration 500-watt(e) radioisotopic thermoelectric generator (RTG) was created. The design effort was divided into two tasks, viz., create a design specification for a capsule strenth member that utilizes a standard Strontium 90 fluoride filled WESF inner liner, and create a conceptual design for a 500-watt(e) RTG. The strength member specification was designed to survive an external pressure of 24,500 psi and meet the requirements of special form radioisotope heat sources. Therefore the capsule is if desired, licensed for domestic and international transport. The design for the RTG features a radioisotopic heat source, an array of nine capsules in a tungsten biological shield, four current technology series connected thermoelectric conversion modules, low conductivity thermal insulation, and a passive finned housing radiator for waste heat dissipation. The preliminary RTG specification formulated previous to contract award was met or exceeded.

  3. Radioisotope Thermophotovoltaic (RTPV) Generator and Its Applicability to an Illustrative Space Mission

    SciTech Connect

    Schock, A.; Mukunda, M.; Or, T.; Kumar, V.; Summers, G.

    1994-02-14

    The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the author. Instead of conducting a generic study, it was decided to focus the design effort by directing it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a post-encounter cruise lasting up to one year.

  4. Detailed mathematical models of a radioisotope thermoelectric generator.

    NASA Technical Reports Server (NTRS)

    Dewinter, F.; Raag, V.

    1972-01-01

    Two new models for the design and performance analysis of RTG's are outlined in this paper. The first model assumes a small-signal transient-type calculational sequence that permits the separation of steady-state operation of the generator from its dynamic behavior. The second model uses a numerical (finite difference) solution of the performance equations of the RTG. Both models enable the investigation of transient and steady-state performance of RTG's. Simplifying assumptions have been kept to a minimum in the new RTG models and these models enable the inclusion of generator end losses, axial temperature gradients and heat interchange between thermoelements and thermal insulation in RTG performance calculations in a self-consistent manner.

  5. Two-watt radioisotope power generators for underwater applications

    NASA Technical Reports Server (NTRS)

    Caputo, R. S.; Truscello, V. C.

    1974-01-01

    Materials and design considerations are discussed for a low-cost, reliable radio-isotope-fueled thermoelectric generator for use in an undersea application. Plutonium has been selected as fuel, and the generator has to meet design goals of 2 watts after 20 years with a direct output voltage of 6-8 volts. The pressed and sintered form of Bi2Te3 appears to be the most appropriate thermoelectric material. Both fibrous and multilayer foil insulation could be used with proper processing and quality control, but there is less risk with fibrous type insulation. Min-K 1400 is recommended with a nitrogen cover gas. The heat source recommended is a three-layer capsule using T-111 for both the liner and strength member with an outer liner of Hastelloy-C.

  6. Test and evaluation of the Navy half-watt RTG. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Rosell, F. E., Jr.; Lane, S. D.; Eggers, P. E.; Gawthrop, W. E.; Rouklove, P. G.; Truscello, V. C.

    1976-01-01

    The radioisotope thermoelectric generator (RTG) considered is to provide a continuous minimum power output of 0.5 watt at 6.0 to 8.5 volts for a minimum period of 15 years. The mechanical-electrical evaluation phase discussed involved the conduction of shock and vibration tests. The thermochemical-physical evaluation phase consisted of an analysis of the materials and the development of a thermal model. The thermoelectric evaluation phase included the accelerated testing of the thermoelectric modules.

  7. Vibration Testing of the Pluto/New Horizons Radioisotope Thermoelectric Generator

    SciTech Connect

    Charles D. Griffin

    2006-06-01

    The Radioisotopic Thermal Generator (RTG) for the Pluto/New Horizons spacecraft was subjected to a flight dynamic acceptance test to demonstrate that it would perform successfully following launch. Seven RTGs of this type had been assembled and tested at Mound, Ohio from 1984 to 1997. This paper chronicles major events in establishing a new vibration test laboratory at the Idaho National Laboratory and the nineteen days of dynamic testing.

  8. Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

    SciTech Connect

    Schock, A.; Noravian, H.; Or, C.

    1997-12-31

    This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that the generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack. The choice of the five-tube cells makes it possible to expand the BASE tube diameter without increasing the cell diameter. This is important because the eight cells mate well with the stacked GPHS modules. The OSC generator design includes a compliant heat source support and preload arrangement, to hold the heat source modules together during launch, and to maintain thermal contact conductance at the generator`s interfaces despite creep relaxation of its housing. The BOM and EOM (up to 15 years) performances of the revised generators were analyzed for two and three GPHS modules, both for fresh fuel and for aged fuel left over from a spare RTG (Radioisotope Thermoelectric Generator) fueled in 1982. The resulting power outputs were compared with JPL`s latest EOM power demand goals for the Pluto Express and Europa Orbiter missions, and with the generic goals of DOE`s Advanced Radioisotope Power System (ARPS) study. The OSC AMTEC designs yielded system

  9. Radioisotope space power generator. Annual report, October 1978-September 1979

    SciTech Connect

    Elsner, N.B.; Chin, J.; Staley, H.G.; Bass, J.C.; Morris, C.C.; Shearer, C.H.; Steeger, E.J.

    1982-03-01

    The emphasis of the Isotec Technology Program shifted from development of a Galileo generator to study of a segmented selenide element and couple technology. The goal of the FY 79 program was to determine the feasibility of fabricating segmented selenide P and N elements which exploit the high thermoelectric efficiency of (Cu,Ag)/sub 2/Se and Gd/sub 2/Se/sub 3/ materials. A preliminary evaluation of segmented element efficiencies, material compatibilities, and fabrication abilities was used to select (Cu,Ag)/sub 2/Se/Fe(Bi,Sb)/sub 2/Te/sub 3/ for the P element and Gd/sub 2/Se/sub 3//PbTe for the N element. The iron barrier between the (Cu,Ag)/sub 2/Se and (Bi,Sb)/sub 2/Te/sub 3/ prevented degradation of thermoelectric properties from copper contamination of the (Bi,Sb)/sub 2/Te/sub 3/. Fabrication processes for both elements were developed. Gd/sub 2/Se/sub 3/ was friable and difficult to fabricate crack-free. It also exhibited a phase transition from cubic to orthorhombic, which increased its susceptibility to microcracking and reduced its thermoelectric efficiency. Life testing of an all-bonded couple with unsegmented (Cu,Ag)/sub 2/Se P-type and Gd/sub 2/Se/sub 3/ N-type elements was stopped after 3300 h in a nominal 830/sup 0/C/390/sup 0/C thermal gradient. The Gd/sub 2/Se/sub 3/ leg did not show any significant degradation during the test. Examination of the hot end of the P element showed the need for a less reactive hot cap material and an improved vapor supression system. Module testing of a 1-W (Bi,Sb)/sub 2/(Se,Te)/sub 3/ generator was performed for 5000 h with no degradation in power. High-temperature Thermid 600 adhesive curing cycles were examined, 75-mW module loading tests were performed, and diagnostic examination of RTG-2A and RTG-201 was completed.

  10. Advanced Stirling Radioisotope Generator (ASRG) Thermal Power Model in MATLAB

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen, J.

    2012-01-01

    This paper presents a one-dimensional steady-state mathematical thermal power model of the ASRG. It aims to provide a guideline of understanding how the ASRG works and what can change its performance. The thermal dynamics and energy balance of the generator is explained using the thermal circuit of the ASRG. The Stirling convertor performance map is used to represent the convertor. How the convertor performance map is coupled in the thermal circuit is explained. The ASRG performance characteristics under i) different sink temperatures and ii) over the years of mission (YOM) are predicted using the one-dimensional model. Two Stirling converter control strategies, i) fixing the hot-end of temperature of the convertor by adjusting piston amplitude and ii) fixing the piston amplitude, were tested in the model. Numerical results show that the first control strategy can result in a higher system efficiency than the second control strategy when the ambient gets warmer or the general-purpose heat source (GPHS) fuel load decays over the YOM. The ASRG performance data presented in this paper doesn't pertain to the ASRG flight unit. Some data of the ASRG engineering unit (EU) and flight unit that are available in public domain are used in this paper for the purpose of numerical studies.

  11. Radioisotope Power System Pool Concept

    NASA Technical Reports Server (NTRS)

    Rusick, Jeffrey J.; Bolotin, Gary S.

    2015-01-01

    Advanced Radioisotope Power Systems (RPS) for NASA deep space science missions have historically used static thermoelectric-based designs because they are highly reliable, and their radioisotope heat sources can be passively cooled throughout the mission life cycle. Recently, a significant effort to develop a dynamic RPS, the Advanced Stirling Radioisotope Generator (ASRG), was conducted by NASA and the Department of Energy, because Stirling based designs offer energy conversion efficiencies four times higher than heritage thermoelectric designs; and the efficiency would proportionately reduce the amount of radioisotope fuel needed for the same power output. However, the long term reliability of a Stirling based design is a concern compared to thermoelectric designs, because for certain Stirling system architectures the radioisotope heat sources must be actively cooled via the dynamic operation of Stirling converters throughout the mission life cycle. To address this reliability concern, a new dynamic Stirling cycle RPS architecture is proposed called the RPS Pool Concept.

  12. Specification for strontium-90 500-watt(e) radioisotopic thermoelectric generator. Final report

    SciTech Connect

    Hammel, T.; Himes, J.; Lieberman, A.; McGrew, J.; Owings, D.; Schumann, F.

    1983-04-01

    A conceptual design for a demonstration 500-watt(e) radioisotopic thermoelectric generator has been created for the Department of Energy. The design effort was divided into two tasks, viz., create a design specification for a capsule strength member that utilizes a standard Strontium-90 fluoride-filled WESF inner liner, and create a conceptual design for a 500-watt(e) RTG. Both tasks have been accomplished. The strength-member specification was designed to survive an external pressure of 24,500 psi and meet the requirements of special-form radioisotope heat sources. Therefore the capsule can, if desired, be licensed for domestic and international transport. The design for the RTG features a radioisotopic heat source, an array of nine capsules in a tungsten biological shield, four current-technology series-connected thermoelectric-conversion modules, low-conductivity thermal insulation, and a passive finned-housing radiator for waste-heat dissipation. The preliminary RTG specification formulated previous to contract award has been met or exceeded. The power source will generate the required power for the required service period at 28 volts dc with a conversion efficiency of 8%, provided the existing in-pool capsules at WESF meet the assumed thermal-inventory requirements.

  13. A prototype on-line work procedure system for radioisotope thermoelectric generator production

    SciTech Connect

    Kiebel, G.R.

    1991-09-01

    An on-line system to manage work procedures is being developed to support radioisotope thermoelectric generator (RTG) assembly and testing in a new production facility. This system implements production work procedures as interactive electronic documents executed at the work site with no intermediate printed form. It provides good control of the creation and application of work procedures and provides active assistance to the worker in performing them and in documenting the results. An extensive prototype of this system is being evaluated to ensure that it will have all the necessary features and that it will fit the user's needs and expectations. This effort has involved the Radioisotope Power Systems Facility (RPSF) operations organization and technology transfer between Westinghouse Hanford Company (Westinghouse Hanford) and EG G Mound Applied Technologies Inc. (Mound) at the US Department of Energy (DOE) Mound Site. 1 ref.

  14. Radioisotope-based Nuclear Power Strategy for Exploration Systems Development

    SciTech Connect

    Schmidt, George R.; Houts, Michael G.

    2006-01-20

    Nuclear power will play an important role in future exploration efforts. Its benefits pertain to practically all the different timeframes associated with the Exploration Vision, from robotic investigation of potential lunar landing sites to long-duration crewed missions on the lunar surface. However, the implementation of nuclear technology must follow a logical progression in capability that meets but does not overwhelm the power requirements for the missions in each exploration timeframe. It is likely that the surface power infrastructure, particularly for early missions, will be distributed in nature. Thus, nuclear sources will have to operate in concert with other types of power and energy storage systems, and must mesh well with the power architectures envisioned for each mission phase. Most importantly, they must demonstrate a clear advantage over other non-nuclear options (e.g., solar power, fuel cells) for their particular function. This paper describes a strategy that does this in the form of three sequential system developments. It begins with use of radioisotope generators currently under development, and applies the power conversion technology developed for these units to the design of a simple, robust reactor power system. The products from these development efforts would eventually serve as the foundation for application of nuclear power systems for exploration of Mars and beyond.

  15. Radioisotope Power System Delivery, Ground Support and Nuclear Safety Implementation: Use of the Multi-Mission Radioisotope Thermoelectric Generator for the NASA's Mars Science Laboratory

    SciTech Connect

    S.G. Johnson; K.L. Lively; C.C. Dwight

    2014-07-01

    Radioisotope power systems have been used for over 50 years to enable missions in remote or hostile environments. They are a convenient means of supplying a few milliwatts up to a few hundred watts of useable, long-term electrical power. With regard to use of a radioisotope power system, the transportation, ground support and implementation of nuclear safety protocols in the field is a complex process that requires clear identification of needed technical and regulatory requirements. The appropriate care must be taken to provide high quality treatment of the item to be moved so it arrives in a condition to fulfill its missions in space. Similarly it must be transported and managed in a manner compliant with requirements for shipment and handling of special nuclear material. This presentation describes transportation, ground support operations and implementation of nuclear safety and security protocols for a radioisotope power system using recent experience involving the Multi-Mission Radioisotope Thermoelectric Generator for National Aeronautics and Space Administration’s Mars Science Laboratory, which launched in November of 2011.

  16. Better, faster, cheaper radioisotope thermoelectric generator for Pluto fast flyby mission

    NASA Astrophysics Data System (ADS)

    Darooka, Dilip K.; Vicente, Francis A.

    1995-01-01

    The authors apply the philosophy of better, faster, cheaper to the selection of a radioisotope power system. Presented are definitions of `Better' and `Faster' capable of evaluation. A cost model, based on Cassini program data, aids in defining `Cheaper'. The study assesses a number of power conversion designs. A systematic approach evaluates these power conversion alternatives. A modified and repacked Cassini—type RTG results as the best choice for mission success.

  17. NASA Glenn Research Center Support of the Advanced Stirling Radioisotope Generator Project

    NASA Technical Reports Server (NTRS)

    Wilson, Scott D.; Wong, Wayne A.

    2015-01-01

    A high-efficiency radioisotope power system was being developed for long-duration NASA space science missions. The U.S. Department of Energy (DOE) managed a flight contract with Lockheed Martin Space Systems Company to build Advanced Stirling Radioisotope Generators (ASRGs), with support from NASA Glenn Research Center. DOE initiated termination of that contract in late 2013, primarily due to budget constraints. Sunpower, Inc., held two parallel contracts to produce Advanced Stirling Convertors (ASCs), one with Lockheed Martin to produce ASC-F flight units, and one with Glenn for the production of ASC-E3 engineering unit "pathfinders" that are built to the flight design. In support of those contracts, Glenn provided testing, materials expertise, Government-furnished equipment, inspection capabilities, and related data products to Lockheed Martin and Sunpower. The technical support included material evaluations, component tests, convertor characterization, and technology transfer. Material evaluations and component tests were performed on various ASC components in order to assess potential life-limiting mechanisms and provide data for reliability models. Convertor level tests were conducted to characterize performance under operating conditions that are representative of various mission conditions. Despite termination of the ASRG flight development contract, NASA continues to recognize the importance of high-efficiency ASC power conversion for Radioisotope Power Systems (RPS) and continues investment in the technology, including the continuation of the ASC-E3 contract. This paper describes key Government support for the ASRG project and future tests to be used to provide data for ongoing reliability assessments.

  18. Work plan for the fabrication of the radioisotope thermoelectric generator transportation system package mounting

    SciTech Connect

    Satoh, J.A.

    1994-11-09

    The Radioisotope Thermoelectric Generator (RTG) has available a dedicated system for the transportation of RTG payloads. The RTG Transportation System (System 100) is comprised of four systems; the Package (System 120), the Semi-trailer (System 140), the Gas Management (System 160), and the Facility Transport (System 180). This document provides guidelines on the fabrication, technical requirements, and quality assurance of the Package Mounting (Subsystem 145), part of System 140. The description follows the Development Control Requirements of WHC-CM-6-1, EP 2.4, Rev. 3.

  19. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2010-01-01

    The Advanced Stirling Radioisotope Generator (ASRG), a high efficiency generator, is being considered for space missions. An engineering unit, the ASRG engineering unit (EU), was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently under extended operation test at the NASA Glenn Research Center (GRC) to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for the ASRG EU. This paper summarizes details of the test facility design, including the mechanical mounting, heat-rejection system, argon system, control systems, and maintenance. The effort proceeded from requirements definition through design, analysis, build, and test. Initial testing and facility performance results are discussed.

  20. Testing of the Advanced Stirling Radioisotope Generator Engineering Unit at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.

    2013-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a high-efficiency generator being developed for potential use on a Discovery 12 space mission. Lockheed Martin designed and fabricated the ASRG Engineering Unit (EU) under contract to the Department of Energy. This unit was delivered to NASA Glenn Research Center in 2008 and has been undergoing extended operation testing to generate long-term performance data for an integrated system. It has also been used for tests to characterize generator operation while varying control parameters and system inputs, both when controlled with an alternating current (AC) bus and with a digital controller. The ASRG EU currently has over 27,000 hours of operation. This paper summarizes all of the tests that have been conducted on the ASRG EU over the past 3 years and provides an overview of the test results and what was learned.

  1. Radiolabeled nanoceria probes may reduce oxidative damages and risk of cancer: a hypothesis for radioisotope-based imaging procedures.

    PubMed

    Bakht, Mohamadreza K; Hosseini, Vahid; Honarpisheh, Hamid

    2013-12-01

    Low-dose ionizing radiations are commonly utilized in medical centers for diagnostic imaging procedures. Unfortunately, the absorption of ionizing radiation generates reactive chemical species that could damage cells. In diagnostic radioisotope-based imaging procedures, the radiological exposures by gamma emitter imaging probes such as radioactive technetium ((99m)Tc) could express low risk of cancer. Recently, many studies have documented cell protective, neuro-protective, anti-inflammatory and cardio-protective properties of cerium oxide nanoparticles (nanoceria) as a result of their antioxidant and free radical scavenger properties. Since there is no safe level of ionizing radiations, then we hypothesize that radiolabeled nanoceria might be an interesting probe to reduce cancer risk and other related oxidative stresses. We also provide a synthetic scheme of nanoceria functionalization with fluorine radiolabeled ligands as an exemplary approach. In conclusion, using nanoceria to combine radioisotope-based imaging probes with antioxidant activity might open new way to protect patient against radioactive emission of radioisotopes and ionizing radiations in several radioisotope-based imaging applications, in particular for patients who need frequent imaging procedures and children who are more susceptible to radiation. PMID:24210631

  2. Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

    2009-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is being considered to power deep space missions. An engineering unit, the ASRG-EU, was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently on an extended operation test at NASA Glenn Research Center to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for testing the ASRG-EU. Details of the test facility design are discussed. The facility can operate the convertors under AC bus control or with the ASRG-EU controller. It can regulate input thermal power in either a fixed temperature or fixed power mode. An enclosure circulates cooled air around the ASRG-EU to remove heat rejected from the ASRG-EU by convection. A custom monitoring and data acquisition system supports the test. Various safety features, which allow 2417 unattended operation, are discussed.

  3. Design Considerations For A Small Scale Radioisotope Thermoelectric Generator System For European Spacecrafts

    NASA Astrophysics Data System (ADS)

    Deacon, Trevor

    2011-10-01

    Photovoltaic cells are the dominant source of primary power for the majority of current space missions particularly those in earth orbits, where adequate power can be generated using solar arrays. The use of solar arrays may not be advantageous for other missions currently being planned by Europe, for example ultra low solar flux missions to the outer planets. Radioisotope thermoelectric generators (RTGs) offer one solution to this problem. The reported developments are the result of an ESA-funded study, led by the University of Leicester with the Fraunhofer Institute and Astrium Ltd. The study investigated the design of a small-scale RTG in the 1 We to 50 We (electrical output power) range, for Mars and deep space environments, although this paper focuses mainly on the 5 We to 50 We range. This paper will review the fundamentals of thermoelectrics and cover the key design elements of a small scale multi-mission RTG system.

  4. The long-term performance degradation of a radioisotope thermoelectric generator using silicon germanium

    NASA Technical Reports Server (NTRS)

    Stapfer, G.; Truscello, V. C.

    1976-01-01

    The successful utilization of a radioisotope thermoelectric generator (RTG) as the power source for spaceflight missions requires that the performance of such an RTG be predictable throughout the mission. Several mechanisms occur within the generator which tend to degrade the performance as a function of operating time. The impact which these mechanisms have on the available output power of an RTG depends primarily on such factors as time, temperature and self-limiting effects. The relative magnitudes, rates and temperature dependency of these various degradation mechanisms have been investigated separately by coupon experiments as well as 4-couple and 18-couple module experiments. This paper discusses the different individual mechanisms and summarizes their combined influence on the performance of an RTG. Also presented as part of the RTG long-term performance characteristics is the sensitivity of the available RTG output power to variations of the individual degradation mechanisms thus identifying the areas of greatest concern for a successful long-term mission.

  5. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L.

    1992-06-01

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  6. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L.

    1992-06-01

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy`s (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE`s Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford`s MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford`s calculations assume five times the GPHS inventory of that assumed for Mound.

  7. System-Level Testing of the Advanced Stirling Radioisotope Generator Engineering Hardware

    NASA Technical Reports Server (NTRS)

    Chan, Jack; Wiser, Jack; Brown, Greg; Florin, Dominic; Oriti, Salvatore M.

    2014-01-01

    To support future NASA deep space missions, a radioisotope power system utilizing Stirling power conversion technology was under development. This development effort was performed under the joint sponsorship of the Department of Energy and NASA, until its termination at the end of 2013 due to budget constraints. The higher conversion efficiency of the Stirling cycle compared with that of the Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, Pluto New Horizons and Mars Science Laboratory) offers the advantage of a four-fold reduction in Pu-238 fuel, thereby extending its limited domestic supply. As part of closeout activities, system-level testing of flight-like Advanced Stirling Convertors (ASCs) with a flight-like ASC Controller Unit (ACU) was performed in February 2014. This hardware is the most representative of the flight design tested to date. The test fully demonstrates the following ACU and system functionality: system startup; ASC control and operation at nominal and worst-case operating conditions; power rectification; DC output power management throughout nominal and out-of-range host voltage levels; ACU fault management, and system command / telemetry via MIL-STD 1553 bus. This testing shows the viability of such a system for future deep space missions and bolsters confidence in the maturity of the flight design.

  8. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    NASA Astrophysics Data System (ADS)

    Sherrell, Dennis L.

    1993-01-01

    A shielded storage rack has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the U.S. Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which processes and stores assembled GPHS modules, prior to their installation into RTGs. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  9. Computational modeling of Radioisotope Thermoelectric Generators (RTG) for interplanetary and deep space travel

    NASA Astrophysics Data System (ADS)

    Nejat, Cyrus; Nejat, Narsis; Nejat, Najmeh

    2014-06-01

    This research project is part of Narsis Nejat Master of Science thesis project that it is done at Shiraz University. The goals of this research are to make a computer model to evaluate the thermal power, electrical power, amount of emitted/absorbed dose, and amount of emitted/absorbed dose rate for static Radioisotope Thermoelectric Generators (RTG)s that is include a comprehensive study of the types of RTG systems and in particular RTG’s fuel resulting from both natural and artificial isotopes, calculation of the permissible dose radioisotope selected from the above, and conceptual design modeling and comparison between several NASA made RTGs with the project computer model pointing out the strong and weakness points for using this model in nuclear industries for simulation. The heat is being converted to electricity by two major methods in RTGs: static conversion and dynamic conversion. The model that is created for this project is for RTGs that heat is being converted to electricity statically. The model approximates good results as being compared with SNAP-3, SNAP-19, MHW, and GPHS RTGs in terms of electrical power, efficiency, specific power, and types of the mission and amount of fuel mass that is required to accomplish the mission.

  10. Certification testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-09-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping counter is a Type B packaging currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to normal and hypothetical accident environments defined in Title 10 of the Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this packaging design. This report documents the testing portion of the design verification. Six tests were conducted on a prototype package: a water spray test, a 4-foot normal conditions drop test, a 30-foot drop test, a 40-inch puncture test, a 30-minute thermal test, and an 8-hour immersion test.

  11. External Magnetic Field Reduction Techniques for the Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.; Geng, Steven M.

    2013-01-01

    Linear alternators coupled to high efficiency Stirling engines are strong candidates for thermal-to-electric power conversion in space. However, the magnetic field emissions, both AC and DC, of these permanent magnet excited alternators can interfere with sensitive instrumentation onboard a spacecraft. Effective methods to mitigate the AC and DC electromagnetic interference (EMI) from solenoidal type linear alternators (like that used in the Advanced Stirling Convertor) have been developed for potential use in the Advanced Stirling Radioisotope Generator. The methods developed avoid the complexity and extra mass inherent in data extraction from multiple sensors or the use of shielding. This paper discusses these methods, and also provides experimental data obtained during breadboard testing of both AC and DC external magnetic field devices.

  12. A compendium of the radioisotope thermoelectric generator transportation system and recent programmatic changes

    SciTech Connect

    Becker, D.L.; McCoy, J.C.

    1996-03-01

    Because RTGs contain significant quantities of radioactive materials, usually plutonium-238 and its decay products, they must be transported in packages built in accordance with 10 CFR 71 (1994). To meet these regulatory requirements, US DOE commissioned Westinghouse Hanford Co. in 1988 to develop a Radioisotope Thermoelectric Generator Transportation System (RTGTS) that would fully comply while protecting RTGs from adverse environmental conditions during normal transport conditions (eg, mainly shock and heat). RTGTS is scheduled for completion Dec. 1996 and will be available to support NASA`s Cassini mission to Saturn in Oct. 1997. This paper provides an overview of the RTGTS project, discusses the hardware being produced, and summarizes various programmatic and management innovations required by recent changes at DOE.

  13. Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs

    SciTech Connect

    Gabriel, D. M.; Miller, G. D.; Bohne, W. A.

    1995-03-16

    The purpose of this document is to serve as the Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) programs performed at EG&G Mound Applied Technologies. As such, it identifies and describes the systems and activities in place to support the requirements contained in DOE Order 5700.6C as reflected in MD-10334, Mound Quality Policy and Responsibilities and the DOE/RPSD supplement, OSA/PQAR-1, Programmatic Quality Assurance Requirements for Space and Terrestrial Nuclear Power Systems. Unique program requirements, including additions, modifications, and exceptions to these quality requirements, are contained in the appendices of this plan. Additional appendices will be added as new programs and activities are added to Mound's HS/RTG mission assignment.

  14. The General-Purpose Heat Source Radioisotope Thermoelectric Generator: A Truly General-Purpose Space RTG

    NASA Astrophysics Data System (ADS)

    Bennett, Gary L.; Lombardo, James J.; Hemler, Richard J.; Silverman, Gil; Whitmore, C. W.; Amos, Wayne R.; Johnson, E. W.; Zocher, Roy W.; Hagan, James C.; Englehart, Richard W.

    2008-01-01

    The General-Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) was developed for the originally planned International Solar Polar Mission (ISPM). [ISPM would later, with the elimination of the NASA spacecraft, become the Ulysses mission.] At 300 We beginning-of-life (BOL) power, the GPHS-RTG was the most powerful RTG with the highest specific power (5.3 We/kg) of any space RTG. These improved performance attributes of the GPHS-RTG made it attractive for use on the Galileo mission. Subsequently, the GPHS-RTG was selected to power the Cassini spacecraft, which is currently orbiting Saturn, and the New Horizons spacecraft which is on its way to Pluto. Truly, the GPHS-RTG is a ``general-purpose'' space RTG.

  15. SNAP 19 Viking RTG flight configuration and integration testing. [Radioisotope Thermoelectric Generator

    NASA Technical Reports Server (NTRS)

    Brittain, W. M.; Christenbury, S. T.

    1974-01-01

    The Viking-75 mission environments and lander interface requirements which influence the design of the RTG (radioisotope thermoelectric generator), as well as RTG-related constraints are discussed. The baseline RTG design evolved from these considerations is presented with particular emphasis on the design features which make the Viking RTG unique. These features include a gas management system employing a separate gas reservoir to maintain the RTG hot junction and heat source temperatures within a desired range throughout the various mission phases, as well as a specially profiled housing/radiator assembly which facilitates both ground cooling of the RTGs prior to launch and thermal control of the lander after landing. Also presented is the expected RTG electrical performance when subjected to the various mission environments/requirements, such as 'power-up' operations in Mars orbit just prior to the entry, and thermal cycling on the Martian surface after landing.

  16. Advanced Stirling Radioisotope Generator Thermal Power Model in Thermal Desktop SINDA/FLUINT Analyzer

    NASA Technical Reports Server (NTRS)

    Wang, Xiao-Yen; Fabanich, William A.; Schmitz, Paul C.

    2012-01-01

    This paper presents a three-dimensional Advanced Stirling Radioisotope Generator (ASRG) thermal power model that was built using the Thermal Desktop SINDA/FLUINT thermal analyzer. The model was correlated with ASRG engineering unit (EU) test data and ASRG flight unit predictions from Lockheed Martin's Ideas TMG thermal model. ASRG performance under (1) ASC hot-end temperatures, (2) ambient temperatures, and (3) years of mission for the general purpose heat source fuel decay was predicted using this model for the flight unit. The results were compared with those reported by Lockheed Martin and showed good agreement. In addition, the model was used to study the performance of the ASRG flight unit for operations on the ground and on the surface of Titan, and the concept of using gold film to reduce thermal loss through insulation was investigated.

  17. Structural testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-06-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping container is a Type B packaging design currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to the normal and hypothetical accident environments defined in Title 10 Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this package design. This report documents the test program portion of the design verification, using several prototype packages. Four types of testing were performed: 30-foot hypothetical accident condition drop tests in three orientations, 40-inch hypothetical accident condition puncture tests in five orientations, a 21 psi external overpressure test, and a normal conditions of transport test consisting of a water spray and a 4 foot drop test. 18 refs., 104 figs., 13 tabs.

  18. RTG's for space exploration at the end of the 20th century. [radioisotope thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Chmielewski, Art

    1989-01-01

    The use of radioisotope thermoelectric generators (RTGs) as energy conversion devices for spacecraft designed for weak-sunlight environments is discussed. The two upcoming missions Galileo and Ulysses will both use general-purpose heat source RTGs. Two other missions that are planned for the mid-nineties and will carry RTGs onboard are the comet rendezvous asteroid flyby and Cassini. Another mission that might become a program start in the last decade of the 20th century is Solarprobe, which is most likely to use modular RTGs. Several other missions that are in different planning stages that are in need of RTGs to meet their power requirements are the Mars rover sample return, planetary (Mars) penetrators, microspacecraft, and the Mars Egg. All of these missions are discssed, stressing their RTG requirements.

  19. Multi-Mission Radioisotope Thermoelectric Generator Heat Exchangers for the Mars Science Laboratory Rover

    NASA Technical Reports Server (NTRS)

    Mastropietro, A. J.; Beatty, John S.; Kelly, Frank P.; Bhandari, Pradeep; Bame, David P.; Liu, Yuanming; Birux, Gajanana C.; Miller, Jennifer R.; Pauken, Michael T.; Illsley, Peter M.

    2012-01-01

    The addition of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) to the Mars Science Laboratory (MSL) Rover requires an advanced thermal control system that is able to both recover and reject the waste heat from the MMRTG as needed in order to maintain the onboard electronics at benign temperatures despite the extreme and widely varying environmental conditions experienced both on the way to Mars and on the Martian surface. Based on the previously successful Mars landed mission thermal control schemes, a mechanically pumped fluid loop (MPFL) architecture was selected as the most robust and efficient means for meeting the MSL thermal requirements. The MSL heat recovery and rejection system (HRS) is comprised of two Freon (CFC-11) MPFLs that interact closely with one another to provide comprehensive thermal management throughout all mission phases. The first loop, called the Rover HRS (RHRS), consists of a set of pumps, thermal control valves, and heat exchangers (HXs) that enables the transport of heat from the MMRTG to the rover electronics during cold conditions or from the electronics straight to the environment for immediate heat rejection during warm conditions. The second loop, called the Cruise HRS (CHRS), is thermally coupled to the RHRS during the cruise to Mars, and provides a means for dissipating the waste heat more directly from the MMRTG as well as from both the cruise stage and rover avionics by promoting circulation to the cruise stage radiators. A multifunctional structure was developed that is capable of both collecting waste heat from the MMRTG and rejecting the waste heat to the surrounding environment. It consists of a pair of honeycomb core sandwich panels with HRS tubes bonded to both sides. Two similar HX assemblies were designed to surround the MMRTG on the aft end of the rover. Heat acquisition is accomplished on the interior (MMRTG facing) surface of each HX while heat rejection is accomplished on the exterior surface of

  20. Considerations in the fabrication, assembly, and testing of radioisotopic thermo-photovoltaic (RTPV) generators for future space missions

    NASA Astrophysics Data System (ADS)

    Barklay, Chadwick D.; Miller, Roger G.; Frazier, Timothy A.

    1996-03-01

    To increase energy output with a smaller size and mass than the radioisotopic thermoelectric generators (RTGs) that were previously used on deep space missions, a radioisotopic thermophotovoltaic (RTPV) system is being developed for the ``Pluto Express'' flyby mission. To minimize cost and development time, some facilities and components currently used for RTG production can be used to produce RTPVs. Production options also include out-sourcing and use of off-the-shelf hardware. Necessary modifications to tooling, production equipment, testing and shipping methods can be achieved in a timely manner so that the RTPV will be ready well before the planned launch of ``Pluto Express.''

  1. Stirling Convertor for the Stirling Radioisotope Generator Tested as a Prelude to Transition to Flight

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2004-01-01

    The Stirling Radioisotope Generator (SRG) is currently being developed by Lockheed Martin Astronautics (Valley Forge, PA) under contract to the Department of Energy (Germantown, MD). In support of this project, the NASA Glenn Research Center has established a near-term technology effort to provide some of the critical data to ensure a successful transition to flight for what will be the first dynamic power system to be used in space. The generator will be a high-efficiency electric power source for potential use on NASA space science missions. The generator will be able to operate in the vacuum of deep space or in an atmosphere such as on the surface of Mars. High system efficiency is obtained through the use of free-piston Stirling power-conversion technology. The power output of the generator will be greater than 100 W at the beginning of life, with the slow decline in power being largely due to decay of the plutonium heat source. Previously, Glenn's supporting technology efforts focused only on the most critical technical issues.

  2. Advanced Stirling Radioisotope Generator Engineering Unit 2 (ASRG EU2) Final Assembly

    NASA Technical Reports Server (NTRS)

    Oriti, Salvatore M.

    2015-01-01

    NASA Glenn Research Center (GRC) has recently completed the assembly of a unique Stirling generator test article for laboratory experimentation. Under the Advanced Stirling Radioisotope Generator (ASRG) flight development contract, NASA GRC initiated a task to design and fabricate a flight-like generator for in-house testing. This test article was given the name ASRG Engineering Unit 2 (EU2) as it was effectively the second engineering unit to be built within the ASRG project. The intent of the test article was to duplicate Lockheed Martin's qualification unit ASRG design as much as possible to enable system-level tests not previously possible at GRC. After the cancellation of the ASRG flight development project, the decision was made to continue the EU2 build, and make use of a portion of the hardware from the flight development project. GRC and Lockheed Martin engineers collaborated to develop assembly procedures, leveraging the valuable knowledge gathered by Lockheed Martin during the ASRG development contract. The ASRG EU2 was then assembled per these procedures at GRC with Lockheed Martin engineers on site. The assembly was completed in August 2014. This paper details the components that were used for the assembly, and the assembly process itself.

  3. Mass Properties Testing and Evaluation for the Multi-Mission Radioisotope Thermoelectric Generator

    SciTech Connect

    Felicione, Frank S.

    2009-12-01

    Mass properties (MP) measurements were performed for the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), serial number (S/N) 0X730401, the power system designated for the Mars Science Laboratory (MSL) mission. Measurements were made using new mounting fixtures at the mass properties testing station in the Idaho National Laboratory (INL) Space and Security Power Systems Facility (SSPSF). The objective of making mass properties measurements was to determine the generator’s flight configured mass and center of mass or center of gravity (CG). Using an extremely accurate platform scale, the mass of the as-tested generator was determined to be 100.117 ± 0.007 lb. Weight accuracy was determined by checking the platform scale with calibrated weights immediately prior to weighing the MMRTG.a CG measurement accuracy was assessed by surrogate testing using an inert mass standard for which the CG could be readily determined analytically. Repeated testing using the mass standard enabled the basic measurement precision of the system to be quantified in terms of a physical confidence interval about the measured CG position. However, repetitious testing with the MMRTG itself was not performed in deference to the gamma and neutron radiation dose to operators and the damage potential to the flight unit from extra handling operations. Since the mass standard had been specially designed to have a total weight and CG location that closely matched the MMRTG, the uncertainties determined from its testing were assigned to the MMRTG as well. On this basis, and at the 99% confidence level, a statistical analysis found the direct, as-measured MMRTG-MSL CG to be located at 10.816 ± 0.0011 in. measured perpendicular from the plane of the lower surface of the generator’s mounting lugs (Z direction), and offset from the generator’s long axis centerline in the X and Y directions by 0.0968 ± 0.0040 in. and 0.0276 ± 0.0026 in., respectively. These uncertainties are based

  4. Over-the-road shock and vibration testing of the radioisotope thermoelectric generator transportation system

    SciTech Connect

    Becker, D.L.

    1997-05-01

    Radioisotope Thermoelectric Generators (RTG) convert heat generated by radioactive decay into electricity through the use of thermocouples. The RTGs have a long operating life, are reasonably lightweight, and require little or no maintenance, which make them particularly attractive for use in spacecraft. However, because RTGs contain significant quantities of radioactive materials, normally plutonium-238 and its decay products, they must be transported in packages built in accordance with Title 10, Code of Federal Regulations, Part 71 (10 CFR 71). To meet these regulations, a RTG Transportation System (RTGTS) that fully complies with 10 CFR 71 has been developed, which protects RTGs from adverse environmental conditions during normal conditions of transport (e.g., shock, vibration, and heat). To ensure the protection of RTGs from shock and vibration loadings during transport, extensive over-the-road testing was conducted on the RTG`S to obtain real-time recordings of accelerations of the air-ride suspension system trailer floor, packaging, and support structure. This paper provides an overview of the RTG`S, a discussion of the shock and vibration testing, and a comparison of the test results to the specified shock response spectra and power spectral density acceleration criteria.

  5. Natural Convection Cooling of the Advanced Stirling Radioisotope Generator Engineering Unit

    NASA Technical Reports Server (NTRS)

    Lewandowski, Edward J.; Hill, Dennis

    2011-01-01

    After fueling and prior to launch, the Advanced Stirling Radioisotope Generator (ASRG) will be stored for a period of time then moved to the launch pad for integration with the space probe and mounting on the launch vehicle. During this time, which could be as long as 3 years, the ASRG will operate continuously with heat rejected from the housing and fins. Typically, the generator will be cooled by forced convection using fans. During some of the ground operations, maintaining forced convection may add significant complexity, so allowing natural convection may simplify operations. A test was conducted on the ASRG Engineering Unit (EU) to quantify temperatures and operating parameters with natural convection only and determine if the EU could be safely operated in such an environment. The results show that with natural convection cooling the ASRG EU Stirling convertor pressure vessel temperatures and other parameters had significant margins while the EU was operated for several days in this configuration. Additionally, an update is provided on ASRG EU testing at NASA Glenn Research Center, where the ASRG EU has operated for over 16,000 hr and underwent extensive testing.

  6. Design, Analysis, and Optimization of a Radioisotope Thermophotovoltaic (RTPV) Generator, and its Applicability to an Illustrative Space Mission

    SciTech Connect

    Schock, Alfred; Mukunda, Meera; Or, Chuen T; Kumar, Vasanth; Summers, G.

    1994-10-01

    Paper presented at the 45th Congress of the IAF in Jerusalem, Israel, October 1994. The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the authors. To focus the design effort, it was decided to direct it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by the JPL, envisages a direct eight to nine-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a six-week post-encounter cruise.

  7. Electron-beam processing of kilogram quantities of iridium for radioisotope thermoelectric generator applications

    SciTech Connect

    Huxford, T.J.; Ohriner, E.K.

    1992-01-01

    Iridium alloys are used as fuel-cladding materials in radioisotope thermoelectric generators (RTGs). Hardware produced at the Oak Ridge National Laboratory (ORNL) has been used in Voyagers I and 2, Galilee, and Ulysses spacecraft. An integral part of the production of iridium-sheet metal involves electron-beam (EB) processing. These processes include the degassing of powder-pressed compacts followed by multiple meltings in order to purify 500-g buttons of Ir-0.3% W alloy. Starting in 1972 and continuing into 1992, our laboratory EB processing was Performed (ca. 1970) in a 60-kW (20 kV at 3 A), two-gun system. In 1991, a new 150-kW EB gun facility was installed to complement the older unit. This paper describes how the newly installed system was qualified for production of RTG developmental work is discussed that will potentially improve the existing process by utilizing the capabilities of the new EB system.

  8. Electron-beam processing of kilogram quantities of iridium for radioisotope thermoelectric generator applications

    SciTech Connect

    Huxford, T.J.; Ohriner, E.K.

    1992-12-31

    Iridium alloys are used as fuel-cladding materials in radioisotope thermoelectric generators (RTGs). Hardware produced at the Oak Ridge National Laboratory (ORNL) has been used in Voyagers I and 2, Galilee, and Ulysses spacecraft. An integral part of the production of iridium-sheet metal involves electron-beam (EB) processing. These processes include the degassing of powder-pressed compacts followed by multiple meltings in order to purify 500-g buttons of Ir-0.3% W alloy. Starting in 1972 and continuing into 1992, our laboratory EB processing was Performed (ca. 1970) in a 60-kW (20 kV at 3 A), two-gun system. In 1991, a new 150-kW EB gun facility was installed to complement the older unit. This paper describes how the newly installed system was qualified for production of RTG developmental work is discussed that will potentially improve the existing process by utilizing the capabilities of the new EB system.

  9. Operational readiness review plan for the radioisotope thermoelectric generator materials production tasks

    SciTech Connect

    Cooper, R.H.; Martin, M.M.; Riggs, C.R.; Beatty, R.L.; Ohriner, E.K.; Escher, R.N.

    1990-04-19

    In October 1989, a US shuttle lifted off from Cape Kennedy carrying the spacecraft Galileo on its mission to Jupiter. In November 1990, a second spacecraft, Ulysses, will be launched from Cape Kennedy with a mission to study the polar regions of the sun. The prime source of power for both spacecraft is a series of radioisotope thermoelectric generators (RTGs), which use plutonium oxide (plutonia) as a heat source. Several of the key components in this power system are required to ensure the safety of both the public and the environment and were manufactured at Oak Ridge National Laboratory (ORNL) in the 1980 to 1983 period. For these two missions, Martin Marietta Energy Systems, Inc. (Energy Systems), will provide an iridium-alloy component used to contain the plutonia heat source and a carbon-composite material that serves as a thermal insulator. ORNL alone will continue to fabricate the carbon-composite material. Because of the importance to DOE that Energy Systems deliver these high-quality components on time, performance of an Operational Readiness Review (ORR) of these manufacturing activities is necessary. Energy Systems Policy GP-24 entitled Operational Readiness Process'' describes the formal and comprehensive process by which appropriate Energy Systems activities are to be reviewed to ensure their readiness. This Energy System policy is aimed at reducing the risks associated with mission success and requires a management-approved readiness plan'' to be issued. This document is the readiness plan for the RTG materials production tasks. 6 refs., 11 figs., 1 tab.

  10. Operational Readiness Review Plan for the Radioisotope Thermoelectric Generator Materials Production Tasks

    DOE R&D Accomplishments Database

    Cooper, R. H.; Martin, M. M.; Riggs, C. R.; Beatty, R. L.; Ohriner, E. K.; Escher, R. N.

    1990-04-19

    In October 1989, a US shuttle lifted off from Cape Kennedy carrying the spacecraft Galileo on its mission to Jupiter. In November 1990, a second spacecraft, Ulysses, will be launched from Cape Kennedy with a mission to study the polar regions of the sun. The prime source of power for both spacecraft is a series of radioisotope thermoelectric generators (RTGs), which use plutonium oxide (plutonia) as a heat source. Several of the key components in this power system are required to ensure the safety of both the public and the environment and were manufactured at Oak Ridge National Laboratory (ORNL) in the 1980 to 1983 period. For these two missions, Martin Marietta Energy Systems, Inc. (Energy Systems), will provide an iridium alloy component used to contain the plutonia heat source and a carbon composite material that serves as a thermal insulator. ORNL alone will continue to fabricate the carbon composite material. Because of the importance to DOE that Energy Systems deliver these high quality components on time, performance of an Operational Readiness Review (ORR) of these manufacturing activities is necessary. Energy Systems Policy GP 24 entitled "Operational Readiness Process" describes the formal and comprehensive process by which appropriate Energy Systems activities are to be reviewed to ensure their readiness. This Energy System policy is aimed at reducing the risks associated with mission success and requires a management approved "readiness plan" to be issued. This document is the readiness plan for the RTG materials production tasks.

  11. Radiation Environments and Exposure Considerations for the Multi-Mission Radioisotope Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Kelly, William M.; Low, Nora M.; Zillmer, Andrew; Johnson, Gregory A.; Normand, Eugene

    2006-01-01

    The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) is the next generation (RTG) being developed by DOE to provide reliable, long-life electric power for NASA's planetary exploration programs. The MMRTG is being developed by Pratt & Whitney Rocketdyne and Teledyne Energy Systems Incorporated (TESI) for use on currently planned and projected flyby, orbital and planet landing missions. This is a significant departure from the design philosophy of the past which was to match specific mission requirements to RTG design capabilities. Undefined mission requirements provide a challenge to system designers by forcing them to put a design envelope around ``all possible missions''. These multi-mission requirements include internal and external radiation sources. Internal sources include the particles ejected by decaying Pu-238 and its daughters plus particles resulting from the interaction of these particles with other MMRTG materials. External sources include the full spectrum of charged particle radiation surrounding planets with magnetic fields and the surfaces of extraterrestrial objects not shielded by magnetic fields. The paper presents the results of investigations into the environments outlined above and the impact of radiation exposure on potential materials to be used on MMRTG and ground support personnel. Mission requirements were also reviewed to evaluate total integrated dose and to project potential shielding requirements for materials. Much of the information on mission shielding requirements was provided by NASA's Jet Propulsion Laboratory. The primary result is an ionizing radiation design curve which indicates the limits to which a particular mission can take the MMRTG in terms of ionizing radiation exposure. Estimates of personnel radiation exposure during ground handling are also provided.

  12. Radiation Environments and Exposure Considerations for the Multi-Mission Radioisotope Thermoelectric Generator

    SciTech Connect

    Kelly, William M.; Low, Nora M.; Zillmer, Andrew; Johnson, Gregory A.; Normand, Eugene

    2006-01-20

    The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) is the next generation (RTG) being developed by DOE to provide reliable, long-life electric power for NASA's planetary exploration programs. The MMRTG is being developed by Pratt and Whitney Rocketdyne and Teledyne Energy Systems Incorporated (TESI) for use on currently planned and projected flyby, orbital and planet landing missions. This is a significant departure from the design philosophy of the past which was to match specific mission requirements to RTG design capabilities. Undefined mission requirements provide a challenge to system designers by forcing them to put a design envelope around 'all possible missions'. These multi-mission requirements include internal and external radiation sources. Internal sources include the particles ejected by decaying Pu-238 and its daughters plus particles resulting from the interaction of these particles with other MMRTG materials. External sources include the full spectrum of charged particle radiation surrounding planets with magnetic fields and the surfaces of extraterrestrial objects not shielded by magnetic fields. The paper presents the results of investigations into the environments outlined above and the impact of radiation exposure on potential materials to be used on MMRTG and ground support personnel. Mission requirements were also reviewed to evaluate total integrated dose and to project potential shielding requirements for materials. Much of the information on mission shielding requirements was provided by NASA's Jet Propulsion Laboratory. The primary result is an ionizing radiation design curve which indicates the limits to which a particular mission can take the MMRTG in terms of ionizing radiation exposure. Estimates of personnel radiation exposure during ground handling are also provided.

  13. Supporting Development for the Stirling Radioisotope Generator and Advanced Stirling Technology Development at NASA GRC

    NASA Astrophysics Data System (ADS)

    Thieme, Lanny G.; Schreiber, Jeffrey G.

    2005-02-01

    A high-efficiency, 110-We (watts electric) Stirling Radioisotope Generator (SRG110) for possible use on future NASA Space Science missions is being developed by the Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). Potential mission use includes providing spacecraft onboard electric power for deep space missions and power for unmanned Mars rovers. GRC is conducting an in-house supporting technology project to assist in SRG110 development. One-, three-, and six-month heater head structural benchmark tests have been completed in support of a heater head life assessment. Testing is underway to evaluate the key epoxy bond of the permanent magnets to the linear alternator stator lamination stack. GRC has completed over 10,000 hours of extended duration testing of the Stirling convertors for the SRG110, and a three-year test of two Stirling convertors in a thermal vacuum environment will be starting shortly. GRC is also developing advanced technology for Stirling convertors, aimed at substantially improving the specific power and efficiency of the convertor and the overall generator. Sunpower, Inc. has begun the development of a lightweight Stirling convertor, under a NASA Research Announcement (NRA) award, that has the potential to double the system specific power to about 8 We/kg. GRC has performed random vibration testing of a lower-power version of this convertor to evaluate robustness for surviving launch vibrations. STC has also completed the initial design of a lightweight convertor. Status of the development of a multi-dimensional computational fluid dynamics code and high-temperature materials work on advanced superalloys, refractory metal alloys, and ceramics are also discussed.

  14. Stirling Research Laboratory Providing Independent Performance Verification of Convertors for a Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.

    2002-01-01

    The Department of Energy (DOE), Germantown, Maryland, Stirling Technology Company (STC), Kennewick, Washington, and NASA Glenn Research Center are developing a free-piston Stirling convertor for a high-efficiency Stirling Radioisotope Generator for NASA Space Science missions. This generator is being developed for multimission use, including providing electric power for unmanned Mars rovers and for deep space missions. STC is developing the 55-W Technology Demonstration Convertor (TDC) under contract to DOE. Glenn is conducting an in-house technology project to assist in developing the convertor for readiness for space qualification and mission implementation. As part of this effort, a Stirling Research Laboratory was established to test the TDC's and related technologies. A key task is providing an independent verification and validation of the TDC performance. Four TDC's are now being tested at Glenn. Acceptance testing has been completed for all convertors, and in general, performance agreed well with that achieved by STC prior to the delivery of the convertors. Performance mapping has also been completed on two of the convertors over a range of hot-end temperatures (450 to 650 C), cold-end temperatures (80 to 120 C), and piston amplitudes (5.2 to 6.2 mm). These test data are available online at http://www.grc.nasa.gov/WWW/tmsb/. The TDC's can be tested in either a horizontal orientation with dual-opposed convertors or in a vertical orientation with a single convertor. Synchronized dual-opposed pairs are used for dynamically balanced operation that results in very low levels of vibration. The Stirling Research Laboratory also supports launch environment testing of the TDC's in Glenn's Structural Dynamics Laboratory and electromagnetic interference and electromagnetic compatibility characterization and reduction efforts. In addition, the TDC's will be used for long-term endurance testing, and preparations are underway for unattended operation.

  15. Supporting Development for the Stirling Radioisotope Generator and Advanced Stirling Technology Development at NASA Glenn

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.; Schreiber, Jeffrey G.

    2005-01-01

    A high-efficiency, 110-W(sub e) (watts electric) Stirling Radioisotope Generator (SRG110) for possible use on future NASA Space Science missions is being developed by the Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). Potential mission use includes providing spacecraft onboard electric power for deep space missions and power for unmanned Mars rovers. GRC is conducting an in-house supporting technology project to assist in SRG110 development. One-, three-, and six-month heater head structural benchmark tests have been completed in support of a heater head life assessment. Testing is underway to evaluate the key epoxy bond of the permanent magnets to the linear alternator stator lamination stack. GRC has completed over 10,000 hours of extended duration testing of the Stirling convertors for the SRG110, and a three-year test of two Stirling convertors in a thermal vacuum environment will be starting shortly. GRC is also developing advanced technology for Stirling convertors, aimed at substantially improving the specific power and efficiency of the convertor and the overall generator. Sunpower, Inc. has begun the development of a lightweight Stirling convertor, under a NASA Research Announcement (NRA) award, that has the potential to double the system specific power to about 8 W(sub e) per kilogram. GRC has performed random vibration testing of a lowerpower version of this convertor to evaluate robustness for surviving launch vibrations. STC has also completed the initial design of a lightweight convertor. Status of the development of a multi-dimensional computational fluid dynamics code and high-temperature materials work on advanced superalloys, refractory metal alloys, and ceramics are also discussed.

  16. Considerations in the fabrication, assembly, and testing of radioisotopic thermo-photovoltaic (RTPV) generators for future space missions

    SciTech Connect

    Barklay, C.D.; Miller, R.G.; Frazier, T.A.

    1996-03-01

    To increase energy output with a smaller size and mass than the radioisotopic thermoelectric generators (RTGs) that were previously used on deep space missions, a radioisotopic thermophotovoltaic (RTPV) system is being developed for the {open_quote}{open_quote}Pluto Express{close_quote}{close_quote} flyby mission. To minimize cost and development time, some facilities and components currently used for RTG production can be used to produce RTPVs. Production options also include out-sourcing and use of off-the-shelf hardware. Necessary modifications to tooling, production equipment, testing and shipping methods can be achieved in a timely manner so that the RTPV will be ready well before the planned launch of {open_quote}{open_quote}Pluto Express.{close_quote}{close_quote} {copyright} {ital 1996 American Institute of Physics.}

  17. Disposition of Radioisotope Thermoelectric Generators Currently Located at the Oak Ridge National Laboratory - 12232

    SciTech Connect

    Glenn, J.; Patterson, J.; DeRoos, K.; Patterson, J.E.; Mitchell, K.G.

    2012-07-01

    Under the American Recovery and Reinvestment Act (ARRA), the U.S. Department of Energy (DOE) awarded SEC Federal Services Corporation (SEC) a 34-building demolition and disposal (D and D) project at the Oak Ridge National Laboratory (ORNL) that included the disposition of six Strontium (Sr-90) powered Radioisotope Thermoelectric Generators (RTGs) stored outside of ORNL Building 3517. Disposition of the RTGs is very complex both in terms of complying with disposal facility waste acceptance criteria (WAC) and U.S. Department of Transportation (DOT) requirements for packaging and transportation in commerce. Two of the RTGs contain elemental mercury which requires them to be Land Disposal Restrictions (LDR) compliant prior to disposal. In addition, all of the RTGs exceed the Class C waste concentration limits under Nuclear Regulatory Commission (NRC) Waste Classification Guidelines. In order to meet the LDR requirements and Nevada National Security Site (NNSS) WAC, a site specific treatability variance for mercury was submitted to the U.S. Environmental Protection Agency (EPA) to allow macro-encapsulation to be an acceptable treatment standard for elemental mercury. By identifying and confirming the design configuration of the mercury containing RTGs, the SEC team proved that the current configuration met the macro-encapsulation standard of 40 Code of Federal Regulations (CFR) 268.45. The SEC Team also worked with NNSS to demonstrate that all radioisotope considerations are compliant with the NNSS low-level waste (LLW) disposal facility performance assessment and WAC. Lastly, the SEC team determined that the GE2000 Type B cask met the necessary size, weight, and thermal loading requirements for five of the six RTGs. The sixth RTG (BUP-500) required a one-time DOT shipment exemption request due to the RTG's large size. The DOT exemption justification for the BUP-500 relies on the inherent robust construction and material make-up of the BUP- 500 RTG. DOE-ORO, SEC, and

  18. Reactor production and processing of radioisotopes for therapeutic applications in nuclear medicine

    SciTech Connect

    Knapp, F.F. Jr.; Mirzadeh, S.; Beets, A.L.

    1995-02-01

    Nuclear reactors continue to play an important role in providing radioisotopes for nuclear medicine. Many reactor-produced radioisotopes are ``neutron rich`` and decay by beta-emission and are thus of interest for therapeutic applications. This talk discusses the production and processing of a variety of reactor-produced radioisotopes of current interest, including those produced by the single neutron capture process, double neutron capture and those available from beta-decay of reactorproduced radioisotopes. Generators prepared from reactorproduced radioisotopes are of particular interest since repeated elution inexpensively provides many patient doses. The development of the alumina-based W-188/Re-188 generator system is discussed in detail.

  19. KOVEC studies of radioisotope thermoelectric generator response (In connection with possible NASA space shuttle accident explosion scenarios)

    SciTech Connect

    Walton, J.; Weston, A.; Lee, E.

    1984-06-26

    The Department of Energy (DOE) commissioned a study leading to a final report (NUS-4543, Report of the Shuttle Transportation System (STS) Explosion Working Group (EWG), June 8, 1984), concerned with PuO/sub 2/ dispersal should the NASA space shuttle explode during the proposed Galileo and ISPN launches planned for 1986. At DOE's request, LLNL furnished appendices that describe hydrocode KOVEC calculations of potential damage to the Radioisotope Thermoelectric Generators, fueled by PuO/sub 2/, should certain explosion scenarios occur. These appendices are contained in this report.

  20. Final Results for the GRC Supporting Technology Development Project for the 110-Watt Stirling Radioisotope Generator (SRG110)

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2007-01-01

    From 1999-2006, the NASA Glenn Research Center (GRC) supported the development of a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions, including deep space missions, Mars rovers, and lunar applications. Lockheed Martin (LM) was the system integrator for the SRG110, under contract to the Department of Energy (DOE). Infinia Corporation (formerly Stirling Technology Company) developed the Stirling convertor, first as a contractor to DOE and then under subcontract to LM. The SRG110 development has been redirected, and recent program changes have been made to significantly increase the specific power of the generator. System development of an Advanced Stirling Radioisotope Generator (ASRG) has now begun, using a lightweight, advanced convertor from Sunpower, Inc. This paper summarizes the results of the supporting technology effort that GRC completed for the SRG110. GRC tasks included convertor extended-duration testing in air and thermal vacuum environments, heater head life assessment, materials studies, permanent magnet aging characterization, linear alternator evaluations, structural dynamics testing, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) characterization, organic materials evaluations, reliability studies, and development of an end-to-end system dynamic model. Related efforts are now continuing in many of these areas to support ASRG development.

  1. Final Results for the GRC Supporting Technology Development Project for the 110-Watt Stirling Radioisotope Generator (SRG110)

    NASA Astrophysics Data System (ADS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2007-01-01

    From 1999-2006, the NASA Glenn Research Center (GRC) supported the development of a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions, including deep space missions. Mars rovers, and lunar applications. Lockheed Martin (LM) was the system integrator for the SRG110, under contact to the Department of Energy (DOE). Infinia Corporation (formerly Stirling Technology Company) developed the Stirling converter. First as a contractor to DOE and then under subcontract to LM. The SRG110 development has been redirected, and recent program changes have been made to significantly increase the specific power of the generator. System development of an Advanced Stirling Radioisotope Generator (ASRG) has now begun, using a lightweight, advanced converter from Sunpower, Inc. This paper summarizes the results of the supporting technology effort that GRC completed for the SRG110. GRC tasks included converter extended-duration testing in air and thermal vacuum environments, heater head life assessment, materials studies, permanent magnet aging characterization, linear alternator evaluations, structural dynamics testing, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) characterization, organic materials evaluations, reliability studies, and development of an end-to-end system dynamic model. Related efforts are now continuing in many of these areas to support ASRG development.

  2. Final Results for the GRC Supporting Technology Development Project for the 110-Watt Stirling Radioisotope Generator (SRG110)

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.; Thieme, Lanny G.

    2007-01-01

    From 1999 to 2006, the NASA Glenn Research Center (GRC) supported the development of a high-efficiency, nominal 110-We Stirling Radioisotope Generator (SRG110) for potential use on NASA missions, including deep space missions, Mars rovers, and lunar applications. Lockheed Martin (LM) was the system integrator for the SRG110, under contract to the Department of Energy (DOE). Infinia Corporation (formerly Stirling Technology Company) developed the Stirling convertor, first as a contractor to DOE and then under subcontract to LM. The SRG110 development has been redirected, and recent program changes have been made to significantly increase the specific power of the generator. System development of an Advanced Stirling Radioisotope Generator (ASRG) has now begun, using a lightweight, advanced convertor from Sunpower, Inc. This paper summarizes the results of the supporting technology effort that GRC completed for the SRG110. GRC tasks included convertor extended-duration testing in air and thermal vacuum environments, heater head life assessment, materials studies, permanent magnet aging characterization, linear alternator evaluations, structural dynamics testing, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) characterization, organic materials evaluations, reliability studies, and development of an end-to-end system dynamic model. Related efforts are now continuing in many of these areas to support ASRG development.

  3. Design, Analysis, and Optimization of a Radioisotope Thermophotovoltaic (RTPV) Generator, and its Applicability to an Illustrative Space Mission

    NASA Astrophysics Data System (ADS)

    Schock, A.; Mukunda, M.; Or, C.; Kumar, V.; Summers, G.

    1995-10-01

    The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the author. To focus the design effort, it was decided to direct it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by the Jet Propulsion Laboratory (JPL), envisages a direct eight to nine-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a six-week post-encounter cruise. Because of Pluto's long distance from the sun (30-50 A.U.) and the mission's large energy demand, JPL has baselined the use of a radioisotope power system for the PFF spacecraft. RTGs have been tentatively selected, because they have been successfully flown on many space missions, and have demonstrated exceptional reliability and durability. The only reason for exploring the applicability of the far less mature RTPV systems is their potential for much higher conversion efficiencies, which would greatly reduce the mass and cost of the required radioisotope heat source. Those attributes are particularly important for the PFF mission, which — like all NASA missions under current consideration — is severely mass- and cost-limited. The paper describes the design of an RTPV system consisting of a radioisotope heat source, a thermophotovoltaic converter, and an optimized heat rejection system; and depicts its integration with the PFF spacecraft. It then describes the optical, thermal, electrical, and structural analyses which led to that optimized design, and compares the computed performance of an RTPV system to that of an RTG designed for the same mission. Our analytical

  4. Radioisotope fueled pulsed power generation system for propulsion and electrical power for deep space missions

    NASA Astrophysics Data System (ADS)

    Howe, Troy

    Space exploration missions to the moon, Mars, and other celestial bodies have allowed for great scientific leaps to enhance our knowledge of the universe; yet the astronomical cost of these missions limits their utility to only a few select agencies. Reducing the cost of exploratory space travel will give rise to a new era of exploration, where private investors, universities, and world governments can send satellites to far off planets and gather important data. By using radioisotope power sources and thermal storage devices, a duty cycle can be introduced to extract large amounts of energy in short amounts of time, allowing for efficient space travel. The same device can also provide electrical power for subsystems such as communications, drills, lasers, or other components that can provide valuable scientific information. This project examines the use of multiple radioisotope sources combined with a thermal capacitor using Phase Change Materials (PCMs) which can collect energy over a period of time. The result of this design culminates in a variety of possible spacecraft with their own varying costs, transit times, and objectives. Among the most promising are missions to Mars which cost less than 17M, missions that can provide power to satellite constellations for decades, or missions that can deliver large, Opportunity-sized (185kg) payloads to mars for less than 53M. All made available to a much wider range of customer with commercially available satellite launches from earth. The true cost of such progress though lies in the sometimes substantial increase in transit times for these missions.

  5. Sublimation behavior of silicon nitride /Si3N4/ coated silicon germanium /SiGe/ unicouples. [for Radioisotope Thermoelectric Generators

    NASA Technical Reports Server (NTRS)

    Stapfer, G.; Truscello, V. C.

    1975-01-01

    For the Multi-Hundred Watt (MHW) Radioisotope Thermoelectric Generator (RTG), the silicon germanium unicouples are coated with silicon nitride to minimize degradation mechanisms which are directly attributable to material sublimation effects. A program is under way to determine the effective vapor suppression of this coating as a function of temperature and gas environment. The results of weight loss experiments, using Si3N4 coated hot shoes (SiMo), operating over a temperature range from 900 C to 1200 C, are analyzed and discussed. These experiments were conducted both in high vacuum and at different pressures of carbon monoxide (CO) to determine its effect on the coating. Although the results show a favorable vapor suppression at all operating temperatures, the pressure of the CO and the thickness of the coating have a decided effect on the useful lifetime of the coating.

  6. General-purpose heat source: Research and development program. Radioisotope thermoelectric generator impact tests: RTG-1 and RTG-2

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.; George, T.G.

    1996-07-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  7. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  8. Proton linac for hospital-based fast neutron therapy and radioisotope production

    SciTech Connect

    Lennox, A.J.; Hendrickson, F.R.; Swenson, D.A.; Winje, R.A.; Young, D.E.; Rush Univ., Chicago, IL; Science Applications International Corp., Princeton, NJ; Fermi National Accelerator Lab., Batavia, IL )

    1989-09-01

    Recent developments in linac technology have led to the design of a hospital-based proton linac for fast neutron therapy. The 180 microamp average current allows beam to be diverted for radioisotope production during treatments while maintaining an acceptable dose rate. During dedicated operation, dose rates greater than 280 neutron rads per minute are achievable at depth, DMAX = 1.6 cm with source to axis distance, SAD = 190 cm. Maximum machine energy is 70 MeV and several intermediate energies are available for optimizing production of isotopes for Positron Emission Tomography and other medical applications. The linac can be used to produce a horizontal or a gantry can be added to the downstream end of the linac for conventional patient positioning. The 70 MeV protons can also be used for proton therapy for ocular melanomas. 17 refs., 1 fig., 1 tab.

  9. System and method to improve the power output and longetivity of a radioisotope thermoelectric generator

    SciTech Connect

    Mowery, A.L. Jr.

    1992-12-31

    By using the helium generated by the alpha emissions of a thermoelectric generator during space travel for cooling the thermal degradation of the thermoelectric generator can be slowed. Slowing degradation allows missions to be longer with little additional expense or payload.

  10. System and method to improve the power output and longetivity of a radioisotope thermoelectric generator

    DOEpatents

    Mowery, Jr., Alfred L.

    1993-01-01

    By using the helium generated by the alpha emissions of a thermoelectric generator during space travel for cooling, the thermal degradation of the thermoelectric generator can be slowed. Slowing degradation allows missions to be longer with little additional expense or payload.

  11. Radioisotope Production for Medical and Physics Applications

    NASA Astrophysics Data System (ADS)

    Mausner, Leonard

    2012-10-01

    Radioisotopes are critical to the science and technology base of the US. Discoveries and applications made as a result of the availability of radioisotopes span widely from medicine, biology, physics, chemistry and homeland security. The clinical use of radioisotopes for medical diagnosis is the largest sector of use, with about 16 million procedures a year in the US. The use of ^99Mo/^99mTc generator and ^18F make up the majority, but ^201Tl, ^123I, ^111In, and ^67Ga are also used routinely to perform imaging of organ function. Application of radioisotopes for therapy is dominated by use of ^131I for thyroid malignancies, ^90Y for some solid tumors, and ^89Sr for bone cancer, but production of several more exotic species such as ^225Ac and ^211At are of significant current research interest. In physics ^225Ra is of interest for CP violation studies, and the actinides ^242Am, ^249Bk, and ^254Es are needed as targets for experiments to create superheavy elements. Large amounts of ^252Cf are needed as a fission source for the CARIBU experiment at ANL. The process of radioisotope production is multidisciplinary. Nuclear physics input based on nuclear reaction excitation function data is needed to choose an optimum target/projectile in order to maximize desired isotope production and minimize unwanted byproducts. Mechanical engineering is needed to address issues of target heating, induced mechanical stress and material compatibility of target and claddings. Radiochemists are involved as well since chemical separation to purify the desired final radioisotope product from the bulk target and impurities is also usually necessary. Most neutron rich species are produced at a few government and university reactors. Other radioisotopes are produced in cyclotrons in the commercial sector, university/hospital based facilities, and larger devices at the DOE labs. The landscape of US facilities, the techniques involved, and current supply challenges will be reviewed.

  12. GPHS-RTG system explosion test direct course experiment 5000. [General Purpose Heat Source-Radioisotope Thermoelectric Generator

    SciTech Connect

    Not Available

    1984-03-01

    The General Purpose Heat Source-Radioisotope Thermoelectric Generator (GPHS-RTG) has been designed and is being built to provide electrical power for spacecrafts to be launched on the Space Shuttle. The objective of the RTG System Explosion Test was to expose a mock-up of the GPHS-RTG with a simulated heat source to the overpressure and impulse representative of a potential upper magnitude explosion of the Space Shuttle. The test was designed so that the heat source module would experience an overpressure at which the survival of the fuel element cladding would be expected to be marginal. Thus, the mock-up was placed where the predicted incident overpressure would be 1300 psi. The mock-up was mounted in an orientation representative of the launch configuration on the spacecraft to be used on the NASA Galileo Mission. The incident overpressure measured was in the range of 1400 to 2100 psi. The mock-up and simulated heat source were destroyed and only very small fragments were recovered. This damage is believed to have resulted from a combination of the overpressure and impact by very high velocity fragments from the ANFO sphere. Post-test analysis indicated that extreme working of the iridium clad material occurred, indicative of intensive impulsive loading on the metal.

  13. The design of a source to simulate the gamma-ray spectrum emitted by a radioisotope thermoelectric generator

    NASA Technical Reports Server (NTRS)

    Reier, M.

    1972-01-01

    A simulated source was designed to duplicate the gamma spectrum of a uniform cylindrical 2200-watt Pu02 radioisotope thermoelectric generator containing 81% Pu-238 and 1.2 ppm Pu-236. Gamma rays from the decay of Pu-238, Am-241, Pu-239, and the 0-18(alpha,n)Ne-21 reaction were catalogued in broad energy groups. Two 46- and one 22-mc Th-228 sources provided simulation at various times in the life of the fuel capsule up to 18 years, which covers the time span of an outer planet mission. Emission from Th-228 represents the overwhelming contribution of the gamma spectrum after the first few years. The sources, in the form of 13-inch rods, were placed in a concentric hole in a cylinder of depleted uranium, which provided shielding equivalent to the self-shielding of the fuel capsule. The thickness of the U-238 cylinder (0.55cm) was determined by Monte Carlo calculations to insure that the spectrum emerging from the simulated source matched that of the fuel capsule.

  14. Epoxy Adhesives for Stator Magnet Assembly in Stirling Radioisotope Generators (SRG)

    NASA Technical Reports Server (NTRS)

    Cater, George M.

    2004-01-01

    As NASA seeks to fulfill its goals of exploration and understanding through missions planned to visit the moons of Saturn and beyond, a number of challenges arise from the idea of deep space flight. One of the first problems associated with deep space travel is electrical power production for systems on the spacecraft. Conventional methods such as solar power are not practical because efficiency decreases substantially as the craft moves away from the Sun. The criterion for power generation during deep space missions are very specific, the main points requiring high reliability, low mass, minimal vibration and a long lifespan. A Stirling generator, although fairly old in concept, is considered to be a potential solution for electrical power generation for deep space flight. A Stirling generator works on the same electromagnetic principles of a standard generator, using the linear motion of the alternator through the stationary stator which produces electric induction. The motion of the alternator, however, is produced by the heating and cooling dynamics of pressurized gases. Essentially heating one end and cooling another of a contained gas will cause a periodic expansion and compression of the gas from one side to the other, which a displacer translates into linear mechanical motion. NASA needs to confirm that the materials used in the generator will be able to withstand the rigors of space and the life expectancy of the mission. I am working on the verification of the epoxy adhesives used to bond magnets to the steel lamination stack to complete the stator; in terms of in-service performance and durability under various space environments. Understanding the proper curing conditions, high temperature properties, and degassing problems as well as production difficulties are crucial to the long term success of the generator. system and steel substrate used in the stator. To optimize the curing conditions of the epoxies, modulated differential scanning calorimetry

  15. Radioisotopic heat source

    DOEpatents

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  16. Creep properties of forged 2219 T6 aluminum alloy shell of general-purpose heat source-radioisotope thermoelectric generator

    SciTech Connect

    Hammond, J.P.

    1981-12-01

    The shell (2219 T6 aluminum forging) of the General Purpose Heat Source-Radioisotope Thermoelectric Generator was designed to retain the generator under sufficient elastic stress to secure it during space flight. A major concern was the extent to which the elastic stress would relax by creep. To determine acceptability of the shell construction material, the following proof tests simulating service were performed: 600 h of testing at 270/sup 0/C under 24.1 MPa stress followed by 10,000 h of storage at 177/sup 0/C under 55.1 MPa, both on the ground; and 10,000 h of flight in space at 270/sup 0/C under 34.4 MPa stress. Additionally, systematic creep testing was performed at 177 and 260/sup 0/C to establish creep design curves. The creep tests performed at 177/sup 0/C revealed comparatively large amounts of primary creep followed by small amounts of secondary creep. The early creep is believed to be abetted by unstable substructures that are annealed out during testing at this temperature. The creep tests performed at 270/sup 0/C showed normal primary creep followed by large amounts of secondary creep. Duplicate proof tests simulating the ground exposure conditions gave results that were in good agreement. The proof test simulating space flight at 270/sup 0/C gave 0.11% primary creep followed by 0.59% secondary creep. About 10% of the second-stage creep was caused by four or five instantaneous strains, which began at the 4500-h mark. One or two of these strain bursts, occurred in each of several other tests at 177 and 260/sup 0/C but were assessed as very moderate in magnitude. The effect is attributable to a slightly microsegregated condition remaining from the original cast structure.

  17. Supporting Development for the Stirling Radioisotope Generator and Advanced Stirling Technology Development at NASA Glenn Research Center

    NASA Technical Reports Server (NTRS)

    Thieme, Lanny G.; Schreiber, Jeffrey G.

    2005-01-01

    A high-efficiency, 110-We (watts electric) Stirling Radioisotope Generator (SRG110) for possible use on future NASA Space Science missions is being developed by the Department of Energy, Lockheed Martin, Stirling Technology Company (STC), and NASA Glenn Research Center (GRC). Potential mission use includes providing spacecraft onboard electric power for deep space missions and power for unmanned Mars rovers. GRC is conducting an in-house supporting technology project to assist in SRG110 development. One-, three-, and six-month heater head structural benchmark tests have been completed in support of a heater head life assessment. Testing is underway to evaluate the key epoxy bond of the permanent magnets to the linear alternator stator lamination stack. GRC has completed over 10,000 hours of extended duration testing of the Stirling convertors for the SRG110, and a three-year test of two Stirling convertors in a thermal vacuum environment will be starting shortly. GRC is also developing advanced technology for Stirling convertors, aimed at substantially improving the specific power and efficiency of the convertor and the overall generator. Sunpower, Inc. has begun the development of a lightweight Stirling convertor, under a NASA Research Announcement (NRA) award, that has the potential to double the system specific power to about 8 We/kg. GRC has performed random vibration testing of a lower-power version of this convertor to evaluate robustness for surviving launch vibrations. STC has also completed the initial design of a lightweight convertor. Status of the development of a multi-dimensional computational fluid dynamics code and high-temperature materials work on advanced superalloys, refractory metal alloys, and ceramics are also discussed.

  18. Radioisotope Thermoelectric Generator Transporation System licensed hardware second certification test series and package shock mount system test

    SciTech Connect

    Ferrell, P.C.; Moody, D.A.

    1995-10-01

    This paper presents a summary of two separate drop test a e performed in support of the Radioisotope Thermoelectric Generator (RTG) Transportation System (RTGTS). The first portion of this paper presents the second series of drop testing required to demonstrate that the RTG package design meets the requirements of Title 10, Code of Federal Regulations, ``Part 71`` (10 CFR 71). Results of the first test series, performed in July 1994, demonstrated that some design changes were necessary. The package design was modified to improve test performance and the design changes were incorporated into the Safety Analysis Report for Packaging (SARP). The second full-size certification test article (CTA-2) incorporated the modified design and was tested at the US Department of Energy`s (DOE) Hanford Site near Richland, Washington. With the successful completion of the test series, and pending DOE Office of Facility Safety Analysis approval of the SARP, a certificate of compliance will be issued for the RTG package allowing its use. The second portion of this paper presents the design and testing of the RTG Package Mount System. The RTG package mount was designed to protect the RTG from excessive vibration during transport, provide shock protection during on/off loading, and provide a mechanism for moving the RTG package with a forklift. Military Standard (MIL-STD) 810E, Transit Drop Procedure (DOE 1989), was used to verify that the shock limiting system limited accelerations in excess of 15 G`s at frequencies below 150 Hz. Results of the package mount drop tests indicate that an impact force of 15 G`s was not exceeded in any test from a free drop height of 457 mm (18 in.).

  19. Radioisotope Thermoelectric Generator Transportation System licensed hardware second certification test series and package shock mount system test

    NASA Astrophysics Data System (ADS)

    Ferrell, Patrick C.; Moody, Donald A.

    1996-03-01

    This paper presents a summary of two separate drop test activities that were performed in support of the Radioisotope Thermoelectric Generator (RTG) Transportation System (RTGTS). The first portion of this paper presents the second series of drop testing required to demonstrate that the RTG package design meets the requirements of Title 10, Code of Federal Regulations, ``Part 71'' (10 CFR 71). Results of the first test series, performed in July 1994, demonstrated that some design changes were necessary. The package design was modified to improve test performance and the design changes were incorporated into the Safety Analysis Report for Packaging (SARP). The second full-size certification test article (CTA-2) incorporated the modified design and was tested at the U.S. Department of Energy's (DOE) Hanford Site near Richland, Washington. With the successful completion of the test series, and pending DOE Office of Facility Safety Analysis approval of the SARP, a certificate of compliance will be issued for the RTG package allowing its use. The second portion of this paper presents the design and testing of the RTG Package Mount System. The RTG package mount was designed to protect the RTG from excessive vibration during transport, provide shock protection during on/off loading, and provide a mechanism for moving the RTG package with a forklift. Military Standard (MIL-STD) 810E, Transit Drop Procedure (DOE 1989), was used to verify that the shock limiting system limited accelerations in excess of 15 G's at frequencies below 150 Hz. Results of the package mount drop tests indicate that an impact force of 15 G's was not exceeded in any test from a free drop height of 457 mm (18 in.).

  20. Radioisotope Thermoelectric Generator Transportation System licensed hardware second certification test series and package shock mount system test

    SciTech Connect

    Ferrell, P.C.; Moody, D.A.

    1996-03-01

    This paper presents a summary of two separate drop test activities that were performed in support of the Radioisotope Thermoelectric Generator (RTG) Transportation System (RTGTS). The first portion of this paper presents the second series of drop testing required to demonstrate that the RTG package design meets the requirements of {ital Title} 10, {ital Code} {ital of} {ital Federal} {ital Regulations}, {open_quote}{open_quote}Part 71{close_quote}{close_quote} (10 CFR 71). Results of the first test series, performed in July 1994, demonstrated that some design changes were necessary. The package design was modified to improve test performance and the design changes were incorporated into the Safety Analysis Report for Packaging (SARP). The second full-size certification test article (CTA-2) incorporated the modified design and was tested at the U.S. Department of Energy{close_quote}s (DOE) Hanford Site near Richland, Washington. With the successful completion of the test series, and pending DOE Office of Facility Safety Analysis approval of the SARP, a certificate of compliance will be issued for the RTG package allowing its use. The second portion of this paper presents the design and testing of the RTG Package Mount System. The RTG package mount was designed to protect the RTG from excessive vibration during transport, provide shock protection during on/off loading, and provide a mechanism for moving the RTG package with a forklift. Military Standard (MIL-STD) 810E, {ital Transit} {ital Drop} {ital Procedure} (DOE 1989), was used to verify that the shock limiting system limited accelerations in excess of 15 G{close_quote}s at frequencies below 150 Hz. Results of the package mount drop tests indicate that an impact force of 15 G{close_quote}s was not exceeded in any test from a free drop height of 457 mm (18 in.). {copyright} {ital 1996 American Institute of Physics.}

  1. Operations of a Radioisotope-based Propulsion System Enabling CubeSat Exploration of the Outer Planets

    SciTech Connect

    Dr. Steven Howe; Nathan Jerred; Troy Howe; Adarsh Rajguru

    2014-05-01

    Exploration to the outer planets is an ongoing endeavor but in the current economical environment, cost reduction is the forefront of all concern. The success of small satellites such as CubeSats launched to Near-Earth Orbit has lead to examine their potential use to achieve cheaper science for deep space applications. However, to achieve lower cost missions; hardware, launch and operations costs must be minimized. Additionally, as we push towards smaller exploration beds with relative limited power sources, allowing for adequate communication back to Earth is imperative. Researchers at the Center for Space Nuclear Research are developing the potential of utilizing an advanced, radioisotope-based system. This system will be capable of providing both the propulsion power needed to reach the destination and the additional requirements needed to maintain communication while at location. Presented here are a basic trajectory analysis, communication link budget and concept of operations of a dual-mode (thermal and electric) radioisotope-based propulsion system, for a proposed mission to Enceladus (Saturnian icy moon) using a 6U CubeSat payload. The radioisotope system being proposed will be the integration of three sub-systems working together to achieve the overall mission. At the core of the system, stored thermal energy from radioisotope decay is transferred to a passing propellant to achieve high thrust – useful for quick orbital maneuvering. An auxiliary closed-loop Brayton cycle can be operated in parallel to the thrusting mode to provide short bursts of high power for high data-rate communications back to Earth. Additionally, a thermal photovoltaic (TPV) energy conversion system will use radiation heat losses from the core. This in turn can provide the electrical energy needed to utilize the efficiency of ion propulsion to achieve quick interplanetary transit times. The intelligent operation to handle all functions of this system under optimized conditions adds

  2. Bismuth-213 and actinium-225 -- generator performance and evolving therapeutic applications of two generator-derived alpha-emitting radioisotopes.

    PubMed

    Morgenstern, Alfred; Bruchertseifer, Frank; Apostolidis, Christos

    2012-07-01

    The alpha emitters (225)Ac and (213)Bi are promising therapeutic radionuclides for application in targeted alpha therapy of cancer and infectious diseases. Both alpha emitters are available with high specific activity from established radionuclide generators. Their favourable chemical and physical properties have led to the conduction of a large number of preclinical studies and several clinical trials, demonstrating the feasibility, safety and therapeutic efficacy of targeted alpha therapy with (225)Ac and (213)Bi. This review describes methods for the production of (225)Ac and (213)Bi and gives an overview of (225)Ac/(213)Bi radionuclide generator systems. Selected preclinical studies are highlighted and the current clinical experience with (225)Ac and (213)Bi is summarized. PMID:22642390

  3. Power from Radioisotopes, Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Corliss, William R.; Mead, Robert L.

    This 1971 revision deals with radioisotopes and their use in power generators. Early developments and applications for the Systems for Nuclear Auxiliary Power (SNAP) and Radioisotope Thermoelectric Generators (RTGs) are reviewed. Present uses in space and on earth are included. Uses in space are as power sources in various satellites and space…

  4. Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.

    2006-01-01

    Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

  5. NASA Radioisotope Power System Program - Technology and Flight Systems

    NASA Technical Reports Server (NTRS)

    Sutliff, Thomas J.; Dudzinski, Leonard A.

    2009-01-01

    NASA sometimes conducts robotic science missions to solar system destinations for which the most appropriate power source is derived from thermal-to-electrical energy conversion of nuclear decay of radioactive isotopes. Typically the use of a radioisotope power system (RPS) has been limited to medium and large-scale missions, with 26 U,S, missions having used radioisotope power since 1961. A research portfolio of ten selected technologies selected in 2003 has progressed to a point of maturity, such that one particular technology may he considered for future mission use: the Advanced Stirling Converter. The Advanced Stirling Radioisotope Generator is a new power system in development based on this Stirling cycle dynamic power conversion technology. This system may be made available for smaller, Discovery-class NASA science missions. To assess possible uses of this new capability, NASA solicited and funded nine study teams to investigate unique opportunities for exploration of potential destinations for small Discovery-class missions. The influence of the results of these studies and the ongoing development of the Advanced Stirling Radioisotope Generator system are discussed in the context of an integrated Radioisotope Power System program. Discussion of other and future technology investments and program opportunities are provided.

  6. Radioisotope electric propulsion of sciencecraft to the outer solar system and near-interstellar space

    SciTech Connect

    Noble, R.J.

    1998-08-01

    Recent results are presented in the study of radioisotope electric propulsion as a near-term technology for sending small robotic sciencecraft to the outer Solar System and near-interstellar space. Radioisotope electric propulsion (REP) systems are low-thrust, ion propulsion units based on radioisotope electric generators and ion thrusters. Powerplant specific masses are expected to be in the range of 100 to 200 kg/kW of thrust power. Planetary rendezvous missions to Pluto, fast missions to the heliopause (100 AU) with the capability to decelerate an orbiter for an extended science program and prestellar missions to the first gravitational lens focus of the Sun (550 AU) are investigated.

  7. Update to the safety program for the general-purpose heat source radioisotope thermoelectric generators for the Galileo and Ulysses missions

    NASA Technical Reports Server (NTRS)

    Bennett, Gary L.; Bradshaw, C. T.; Englehart, Richard W.; Bartram, Bart W.; Cull, Theresa A.; Zocher, Roy W.; Eck, Marshall B.; Mukunda, Meera; Brenza, Peter T.; Chan, Chris C.

    1992-01-01

    With the rescheduling of the Galileo and Ulysses launches and the use of new upper stages following the Challenger accident, the aerospace nuclear safety program for the general-purpose heat source radioisotope thermoelectric generators (GPHS-RTGs) was extended to accommodate the new mission scenarios. As in the original safety program, the objectives were to determine the response of the GPHS-RTG to the various postulated accident environments and to determine the risk (if any) associated with these postulated accidents. The extended GPHS-RTG safety program was successfully completed in sufficient time to prepare an updated Final Safety Analysis Report (FSAR) with revisions for the October 1989 launch of the Galileo spacecraft.

  8. A radioisotope based methodology for plant-fungal interactions in the rhizosphere

    SciTech Connect

    Weisenberger, A. G.; Bonito, G.; Lee, S.; McKisson, J. E.; Gryganskyi, A.; Reid, C. D.; Smith, M. F.; Vaidyanathan, G.; Welch, B.

    2013-10-01

    In plant ecophysiology research there is interest in studying the biology of the rhizosphere because of its importance in plant nutrient-interactions. The rhizosphere is the zone of soil surrounding a plant's root system where microbes (such as fungi) are influenced by the root and the roots by the microbes. We are investigating a methodology for imaging the distribution of molecular compounds of interest in the rhizosphere without disturbing the root or soil habitat. Our intention is to develop a single photon emission computed tomography (SPECT) system (PhytoSPECT) to image the bio-distribution of fungi in association with a host plant's roots. The technique we are exploring makes use of radioactive isotopes as tracers to label molecules that bind to fungal-specific compounds of interest and to image the fungi distribution in the plant and/or soil. We report on initial experiments designed to test the ability of fungal-specific compounds labeled with an iodine radioisotope that binds to chitin monomers (N-acetylglucosamine). Chitin is a compound not found in roots but in fungal cell walls. We will test the ability to label the compound with radioactive isotopes of iodine ({sup 125}I, and {sup 123}I).

  9. The Use of Redundancy to Improve Reliability of Deep Space Missions Using Stirling Radioisotope Generator Power Sources

    NASA Technical Reports Server (NTRS)

    Bolotin, Gary; Everline, Chet; Schmitz, Paul; Distefano, Sal

    2014-01-01

    This study will look at the 140 We class generator as originally envisioned for the ASRG and a larger generator that is scaled up to use four times the fuel. The results discussed below quantify the effect of the use of smaller generators and indicates that a scheme that makes use of several smaller generators enhances the system reliability and allows for more graceful degradation.

  10. Radioisotope power system options for future planetary missions

    NASA Astrophysics Data System (ADS)

    Cockfield, Robert D.

    2001-02-01

    Like previous missions to the outer planets, future spacecraft missions such as Pluto/Kuiper Express, Europa Orbiter, and Solar Probe will require radioisotope power systems for their long voyages away from the Sun. Several candidate advanced power conversion technologies have been proposed that have been proposed that have higher power conversion efficiencies than the traditional thermoelectric generators, with the potential for reduced mass and reduced quantities of nuclear fuel required. Studies conducted by Lockheed Martin under the direction of the Department of Energy have included the development of system conceptual designs utilizing Alkali Metal to Electric Conversion (AMTEC) and Stirling power conversion. Generator concepts based on these conversion technologies are compared in this paper with an alternative Small RTG, based on the General Purpose Heat Source-Radioisotope Thermoelectric Generator (GPHS-RTG). .

  11. Radioisotope Electric Propulsion (REP): A Near-Term Approach to Nuclear Propulsion

    NASA Technical Reports Server (NTRS)

    Schmidt, George R.; Manzella, David H.; Kamhawi, Hani; Kremic, Tibor; Oleson, Steven R.; Dankanich, John W.; Dudzinski, Leonard A.

    2009-01-01

    Studies over the last decade have shown radioisotope-based nuclear electric propulsion to be enhancing and, in some cases, enabling for many potential robotic science missions. Also known as radioisotope electric propulsion (REP), the technology offers the performance advantages of traditional reactor-powered electric propulsion (i.e., high specific impulse propulsion at large distances from the Sun), but with much smaller, affordable spacecraft. Future use of REP requires development of radioisotope power sources with system specific powers well above that of current systems. The US Department of Energy and NASA have developed an advanced Stirling radioisotope generator (ASRG) engineering unit, which was subjected to rigorous flight qualification-level tests in 2008, and began extended lifetime testing later that year. This advancement, along with recent work on small ion thrusters and life extension technology for Hall thrusters, could enable missions using REP sometime during the next decade.

  12. Estimates for production of radioisotopes of medical interest at Extreme Light Infrastructure - Nuclear Physics facility

    NASA Astrophysics Data System (ADS)

    Luo, Wen; Bobeica, Mariana; Gheorghe, Ioana; Filipescu, Dan M.; Niculae, Dana; Balabanski, Dimiter L.

    2016-01-01

    We report Monte Carlo simulations of the production of radioisotopes of medical interest through photoneutron reactions using the high-brilliance γ-beam of the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility. The specific activity for three benchmark radioisotopes, 99Mo/99Tc, 225Ra/225Ac and 186Re, was obtained as a function of target geometry, irradiation time and γ-beam energy. Optimized conditions for the generation of these radioisotopes of medical interest with the ELI-NP γ-beams were discussed. We estimated that a saturation specific activity of the order of 1-2 mCi/g can be achieved for thin targets with about one gram of mass considering a γ-beam flux of 10^{11} photons/s. Based on these results, we suggest that the ELI-NP facility can provide a unique possibility for the production of radioisotopes in sufficient quantities for nuclear medicine research.

  13. Radioisotope electric propulsion (REP): A near-term approach to nuclear propulsion

    NASA Astrophysics Data System (ADS)

    Schmidt, George R.; Manzella, David H.; Kamhawi, Hani; Kremic, Tibor; Oleson, Steven R.; Dankanich, John W.; Dudzinski, Leonard A.

    2010-02-01

    Studies over the last decade have shown radioisotope-based nuclear electric propulsion to be enhancing and, in some cases, enabling for many potential robotic science missions. Also known as radioisotope electric propulsion (REP), the technology offers the performance advantages of traditional reactor-powered electric propulsion (i.e., high specific impulse propulsion at large distances from the Sun), but with much smaller, affordable spacecraft. Future use of REP requires development of radioisotope power sources with system specific powers well above that of current systems. The US Department of Energy and NASA have developed an advanced Stirling radioisotope generator (ASRG) engineering unit, which was subjected to rigorous flight qualification-level tests in 2008, and began extended lifetime testing later that year. This advancement, along with recent work on small ion thrusters and life extension technology for Hall thrusters, could enable missions using REP sometime during the next decade.

  14. Simultaneous detection and removal of radioisotopes with modified alginate beads containing an azo-based probe using RGB coordinates.

    PubMed

    Jo, Ara; Jang, Geunseok; Namgung, Ho; Kim, Choongho; Kim, Daigeun; Kim, Yujun; Kim, Jongho; Lee, Taek Seung

    2015-12-30

    We prepared alginate beads that were modified with an azo-based probe molecule to monitor simultaneously the removal (by alginate) and probing (by the azo-probe molecule) of radioisotopes such as cobalt, strontium, and cesium ions. As an azo-probe molecule, Basic Orange 2 (BO2) was immobilized to the alginate bead. The BO2 in aqueous solution exhibited a slight red shift in absorption with a change in color from orange to dark orange upon addition of cobalt and strontium ions. In contrast, the color of BO2 did not change upon exposure to cesium ions. Thus, the covalently embedded BO2 in alginate beads could adsorb cobalt and strontium ions resulting in recognizable color change of the beads, which was induced by the formation of a complex between BO2 and metal ions. The color changes of the beads in the presence of metal ions were determined quantitatively using RGB color coordinate values. In addition to effectively removing metal ions, the colorimetric coordinate method provides a convenient and simple sensing technique for naked-eye metal ion detection. PMID:26188865

  15. Radioisotope electric propulsion of sciencecraft to the outer Solar System and near-interstellar space

    SciTech Connect

    Noble, R.J.

    1999-11-01

    Radioisotopes have been used successfully for more than 25 years to supply the heat for thermoelectric generators on various deep-space probes. Radioisotope electric propulsion (REP) systems have been proposed as low-thrust ion propulsion units based on radioisotope electric generators and ion thrusters. The perceived liability of radioisotope electric generators for ion propulsion is their high mass. Conventional radioisotope thermoelectric generators have a specific mass of about 200 kg/kW of electric power. Many development efforts have been undertaken with the aim of reducing the specific mass of radioisotope electric systems. Recent performance estimates suggest that specific masses of 50 kg/kW may be achievable with thermophotovoltaic and alkali metal thermal-to-electric conversion generators. Powerplants constructed from these near-term radioisotope electric generators and long-life ion thrusters will likely have specific masses in the range of 100 to 200 kg/kW of thrust power if development continues over the next decade. In earlier studies, it was concluded that flight times within the Solar System are indeed insensitive to reductions in the powerplant specific mass, and that a timely scientific program of robotic planetary rendezvous and near-interstellar space missions is enabled by primary electric propulsion once the powerplant specific mass is in the range of 100 to 200 kg/kW. Flight times can be substantially reduced by using hybrid propulsion schemes that combine chemical propulsion, gravity assist, and electric propulsion. Hybrid schemes are further explored in this article to illustrate how the performance of REP is enhanced for Pluto rendezvous, heliopause orbiter, and gravitational lens missions.

  16. Use of Historical Personnel Exposure in Facility Safety Analyses, Program Planning, and Minimizing of Personnel Exposure in Assembly and Testing of Radioisotope Thermoelectric Generators

    NASA Astrophysics Data System (ADS)

    Johnson, Ernest W.

    1994-07-01

    The minimization of personnel exposure when assembling plutonium-238-fueled heat sources/radioisotope thermoelectric generators (RTGs) is a Department of Energy (DOE) requirement per DOE Order 5480.11. In addition, DOE Orders 5480.23 and 5481.1B regarding facility safety requisites define that radiological effects on operating staff be quantitatively identified from a probabilistic standpoint. In the assembly of General Purpose Heat Source (GPHS) RTGs at the Mound Facility to support the Galileo and Ulysses Missions, personnel radiation exposure data were used to support the Building 50 Final Safety Analysis Report (FSAR) and identified facility and procedural modifications for the future Cassini Mission GPHS RTG manufacture to reduce this exposure. Similar studies were made on personnel radiological exposure data in the heat source assembly and terrestrial RTG assembly facilities in Building 38. No major procedure and facility modifications were suggested. The Building 38 FSAR was enhanced as to exposure exceedance probabilities; these were in the 10-6 per year operating person regime.

  17. The F1 Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) : a Power Subsystem Enabler for the Mars Science Laboratory (MSL) Mission

    NASA Technical Reports Server (NTRS)

    Jones, Loren; Moreno, Victor; Zimmerman, Robert

    2013-01-01

    The Mars Science Laboratory (MSL) spacecraft carrying the Curiosity rover launched from Cape Canaveral Air Force Station (CCAFS) on November 26, 2011. Following an 8.5-month cruise and after a successful Entry, Descent and Landing (EDL) phase, the Curiosity rover arrived at the surface of Mars on August 6, 2012 UTC. At the core of the Curiosity rover power subsystem is the F1 Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) supplied by the Department of Energy. Integration of the F1 MMRTG into the MSL spacecraft has provided the first opportunity to architect a power subsystem that also included a Solar Array (during the cruise phase of the mission and up to the initial stage of the EDL phase) and secondary Li-ion batteries for operation during the planned one Martian year surface phase of the mission. This paper describes the F1 MMRTG functional features as an enabler of the MSL mission and as a novel component of the MSL power subsystem architecture.

  18. Silicon Carbide Radioisotope Batteries

    NASA Technical Reports Server (NTRS)

    Rybicki, George C.

    2005-01-01

    The substantial radiation resistance and large bandgap of SiC semiconductor materials makes them an attractive candidate for application in a high efficiency, long life radioisotope battery. To evaluate their potential in this application, simulated batteries were constructed using SiC diodes and the alpha particle emitter Americium Am-241 or the beta particle emitter Promethium Pm-147. The Am-241 based battery showed high initial power output and an initial conversion efficiency of approximately 16%, but the power output decayed 52% in 500 hours due to radiation damage. In contrast the Pm-147 based battery showed a similar power output level and an initial conversion efficiency of approximately 0.6%, but no degradation was observed in 500 hours. However, the Pm-147 battery required approximately 1000 times the particle fluence as the Am-242 battery to achieve a similar power output. The advantages and disadvantages of each type of battery and suggestions for future improvements will be discussed.

  19. Metadata based mediator generation

    SciTech Connect

    Critchlow, T

    1998-03-01

    Mediators are a critical component of any data warehouse, particularly one utilizing partially materialized views; they transform data from its source format to the warehouse representation while resolving semantic and syntactic conflicts. The close relationship between mediators and databases, requires a mediator to be updated whenever an associated schema is modified. This maintenance may be a significant undertaking if a warehouse integrates several dynamic data sources. However, failure to quickly perform these updates significantly reduces the reliability of the warehouse because queries do not have access to the m current data. This may result in incorrect or misleading responses, and reduce user confidence in the warehouse. This paper describes a metadata framework, and associated software designed to automate a significant portion of the mediator generation task and thereby reduce the effort involved in adapting the schema changes. By allowing the DBA to concentrate on identifying the modifications at a high level, instead of reprogramming the mediator, turnaround time is reduced and warehouse reliability is improved.

  20. Advanced Radioisotope Power Systems Segmented Thermoelectric Research

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry

    2004-01-01

    Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

  1. Radioisotopes: Today's Applications.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Nuclear Energy Office.

    Radioisotopes are useful because of their three unique characteristics: (1) radiation emission; (2) predictable radioactive lives; and (3) the same chemical properties as the nonradioactive atoms of that element. Researchers are able to "order" a radioisotope with the right radiation, half-life, and chemical property to perform a given task with…

  2. NASA's Radioisotope Power Systems Program Status

    NASA Technical Reports Server (NTRS)

    Dudzinski, Leonard A.; Hamley, John A.; McCallum, Peter W.; Sutliff, Thomas J.; Zakrajsek, June F.

    2013-01-01

    NASA's Radioisotope Power Systems (RPS) Program began formal implementation in December 2010. The RPS Program's goal is to make available RPS for the exploration of the solar system in environments where conventional solar or chemical power generation is impractical or impossible to meet mission needs. To meet this goal, the RPS Program manages investments in RPS system development and RPS technologies. The current keystone of the RPS Program is the development of the Advanced Stirling Radioisotope Generator (ASRG). This generator will be about four times more efficient than the more traditional thermoelectric generators, while providing a similar amount of power. This paper provides the status of the RPS Program and its related projects. Opportunities for RPS generator development and targeted research into RPS component performance enhancements, as well as constraints dealing with the supply of radioisotope fuel, are also discussed in the context of the next ten years of planetary science mission plans.

  3. Rhenium Radioisotopes for Therapeutic Radiopharmaceutical Development

    SciTech Connect

    Beets, A.L.; Knapp, F.F., Jr.; Kropp, J.; Lin, W.-Y.; Pinkert, J.; Wang, S.-Y.

    1999-01-18

    The availability of therapeutic radioisotopes at reasonable costs is important for applications in nuclear medicine, oncology and interventional cardiology, Rhenium-186 (Re-186) and rhenium-1 88 (Re-188) are two reactor-produced radioisotope which are attractive for a variety of therapeutic applications, Rhenium-186 has a half-life of 90 hours and decays with emission of a &particle with a maximum energy of 1.08 MeV and a 135 keV (9Yo) gamma which permits imaging. In contrast, Re- 188 has a much shorter half-life of 16.9 hours and emits a p-particle with a much higher energy of 2.12 MeV (Em=) and a 155 keV gamma photon (15Yo) for imaging. While Re-186 is unavailable from a generator system and must be directly produced in a nuclear reactor, Re-188 can also be directly produced in a reactor with high specific activity, but is more conveniently and cost-effectively available as carrier-free sodium perrhenate by saline elution of the alumina-based tungsten-188 (W1 88)/Re-l 88 generator system [1-2]. Since a comprehensive overviewofRe-186 and Re-188 therapeutic agents is beyond the scope of this &tended Abstrac4 the goal is to provide key examples of various agents currently in clinical use and those which are being developed for important clinical applications.

  4. Photography-based image generator

    NASA Astrophysics Data System (ADS)

    Dalton, Nicholas M.; Deering, Charles S.

    1989-09-01

    A two-channel Photography Based Image Generator system was developed to drive the Helmet Mounted Laser Projector at the Naval Training System Center at Orlando, Florida. This projector is a two-channel system that displays a wide field-of-view color image with a high-resolution inset to efficiently match the pilot's visual capability. The image generator is a derivative of the LTV-developed visual system installed in the A-7E Weapon System Trainer at NAS Cecil Field. The Photography Based Image Generator is based on patented LTV technology for high resolution, multi-channel, real world visual simulation. Special provisions were developed for driving the NTSC-developed and patented Helmet Mounted Laser Projector. These include a special 1023-line raster format, an electronic image blending technique, spherical lens mapping for dome projection, a special computer interface for head/eye tracking and flight parameters, special software, and a number of data bases. Good gaze angle tracking is critical to the use of the NTSC projector in a flight simulation environment. The Photography Based Image Generator provides superior dynamic response by performing a relatively simple perspective transformation on stored, high-detail photography instead of generating this detail by "brute force" computer image generation methods. With this approach, high detail can be displayed and updated at the television field rate (60 Hz).

  5. Computer-based structure generation

    NASA Astrophysics Data System (ADS)

    Korytko, Andrey A.

    The program HOUDINI has been designed to construct all structures consistent with structural implications of spectroscopic and other properties of an unknown molecule. With the advent of HOUDINI, a new method of computer structure generation, called convergent structure generation, has been developed that addresses the limitations of earlier methods. Several features of HOUDINI are noteworthy: an integrated application of the collective substructural information; the use of parallel atom groups for a highly efficient handling of alternative substructural inferences; and a managed structure generation procedure designed to build required structural features early in the process. A number of complex structure elucidation problems were solved using the HOUDINI-based comprehensive structure elucidation system. The program performance suggests that convergent structure generation is effective in solving structure problems where much of the input to the structure generator is highly ambiguous, i.e., expressed as families of alternative substructural inferences.

  6. Radioisotopic heat source

    DOEpatents

    Sayell, E.H.

    1973-10-23

    A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

  7. Micromotor-based energy generation.

    PubMed

    Singh, Virendra V; Soto, Fernando; Kaufmann, Kevin; Wang, Joseph

    2015-06-01

    A micromotor-based strategy for energy generation, utilizing the conversion of liquid-phase hydrogen to usable hydrogen gas (H2), is described. The new motion-based H2-generation concept relies on the movement of Pt-black/Ti Janus microparticle motors in a solution of sodium borohydride (NaBH4) fuel. This is the first report of using NaBH4 for powering micromotors. The autonomous motion of these catalytic micromotors, as well as their bubble generation, leads to enhanced mixing and transport of NaBH4 towards the Pt-black catalytic surface (compared to static microparticles or films), and hence to a substantially faster rate of H2 production. The practical utility of these micromotors is illustrated by powering a hydrogen-oxygen fuel cell car by an on-board motion-based hydrogen and oxygen generation. The new micromotor approach paves the way for the development of efficient on-site energy generation for powering external devices or meeting growing demands on the energy grid. PMID:25906739

  8. Advanced radioisotope power source options for Pluto Express

    SciTech Connect

    Underwood, M.L.

    1995-12-31

    In the drive to reduce mass and cost, Pluto Express is investigating using an advanced power conversion technology in a small Radioisotope Power Source (RPS) to deliver the required mission power of 74 W(electric) at end of mission. Until this year the baseline power source under consideration has been a Radioisotope Thermoelectric Generator (RTG). This RTG would be a scaled down GPHS RTG with an inventory of 6 General Purpose Heat Sources (GPHS) and a mass of 17.8 kg. High efficiency, advanced technology conversion options are being examined to lower the power source mass and to reduce the amount of radioisotope needed. Three technologies are being considered as the advanced converter technology: the Alkali Metal Thermal-to-Electric Converter (AMTEC), Thermophotovoltaic (TPV) converters, and Stirling Engines. Conceptual designs for each of these options have been prepared. Each converter would require only 2 GPHSs to provide the mission power and would have a mass of 6.1, 7.2, and 12.4 kg for AMTEC, TPV, and Stirling Engines respectively. This paper reviews the status of each technology and the projected performance of an advanced RPS based on each technology. Based on the projected performance and spacecraft integration issues, Pluto Express would prefer to use the AMTEC based RPS. However, in addition to technical performance, selection of a power technology will be based on many other factors.

  9. Environmental assessment for radioisotope heat source fuel processing and fabrication

    SciTech Connect

    Not Available

    1991-07-01

    DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs.

  10. The flow mechanism in the Chalk based on radio-isotope analyses of groundwater in the London Basin

    USGS Publications Warehouse

    Downing, R.A.; Pearson, F.J.; Smith, D.B.

    1979-01-01

    14C analyses of groundwaters from the Chalk of the London Basin are re-interpreted and the age of the groundwater is revised. Radio-isotope analyses are used to examine the flow mechanism in the aquifer. The evidence supports the view that a network of micro-fissures and larger intergranular pores in the matrix provides a significant part of the water pumped from Chalk wells and the major fissures distribute the water to the wells. Most of the matrix is fine-grained and contains a very old water. This diffuses into the micro-fissures and larger pores and is carried to the wells by the major fissures. ?? 1979.

  11. Radioisotope Power: A Key Technology for Deep Space Exploration

    NASA Technical Reports Server (NTRS)

    Schmidt, George; Sutliff, Tom; Dudzinski, Leonard

    2008-01-01

    A Radioisotope Power System (RPS) generates power by converting the heat released from the nuclear decay of radioactive isotopes, such as Plutonium-238 (Pu-238), into electricity. First used in space by the U.S. in 1961, these devices have enabled some of the most challenging and exciting space missions in history, including the Pioneer and Voyager probes to the outer solar system; the Apollo lunar surface experiments; the Viking landers; the Ulysses polar orbital mission about the Sun; the Galileo mission to Jupiter; the Cassini mission orbiting Saturn; and the recently launched New Horizons mission to Pluto. Radioisotopes have also served as a versatile heat source for moderating equipment thermal environments on these and many other missions, including the Mars exploration rovers, Spirit and Opportunity. The key advantage of RPS is its ability to operate continuously, independent of orientation and distance relative to the Sun. Radioisotope systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, autonomous operations in the extreme conditions of space and other planetary bodies. This paper reviews the history of RPS for the U.S. space program. It also describes current development of a new Stirling cycle-based generator that will greatly expand the application of nuclear-powered missions in the future.

  12. Radioisotope Power: A Key Technology for Deep Space Explorations

    NASA Technical Reports Server (NTRS)

    Schmidt, George R.; Sutliff, Thomas J.; Duddzinski, Leonard

    2009-01-01

    A Radioisotope Power System (RPS) generates power by converting the heat released from the nuclear decay of radioactive isotopes, such as Plutonium-238 (Pu-238), into electricity. First used in space by the U.S. in 1961, these devices have enabled some of the most challenging and exciting space missions in history, including the Pioneer and Voyager probes to the outer solar system; the Apollo lunar surface experiments; the Viking landers; the Ulysses polar orbital mission about the Sun; the Galileo mission to Jupiter; the Cassini mission orbiting Saturn; and the recently launched New Horizons mission to Pluto. Radioisotopes have also served as a versatile heat source for moderating equipment thermal environments on these and many other missions, including the Mars exploration rovers, Spirit and Opportunity. The key advantage of RPS is its ability to operate continuously, independent of orientation and distance relative to the Sun. Radioisotope systems are long-lived, rugged, compact, highly reliable, and relatively insensitive to radiation and other environmental effects. As such, they are ideally suited for missions involving long-lived, autonomous operations in the extreme conditions of space and other planetary bodies. This paper reviews the history of RPS for the U.S. space program. It also describes current development of a new Stirling cycle-based generator that will greatly expand the application of nuclear-powered missions in the future.

  13. Wavelet-Based Grid Generation

    NASA Technical Reports Server (NTRS)

    Jameson, Leland

    1996-01-01

    Wavelets can provide a basis set in which the basis functions are constructed by dilating and translating a fixed function known as the mother wavelet. The mother wavelet can be seen as a high pass filter in the frequency domain. The process of dilating and expanding this high-pass filter can be seen as altering the frequency range that is 'passed' or detected. The process of translation moves this high-pass filter throughout the domain, thereby providing a mechanism to detect the frequencies or scales of information at every location. This is exactly the type of information that is needed for effective grid generation. This paper provides motivation to use wavelets for grid generation in addition to providing the final product: source code for wavelet-based grid generation.

  14. Energy Recovery Linacs for Commercial Radioisotope Production

    SciTech Connect

    Sy, Amy; Krafft, Geoffrey A.; Johnson, Rolland; Roberts, Tom; Boulware, Chase; Hollister, Jerry

    2015-09-01

    Photonuclear reactions with bremsstrahlung photon beams from electron linacs can generate radioisotopes of critical interest. An SRF Energy Recovery Linac (ERL) provides a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes in a more compact footprint and at a lower cost than those produced by conventional reactor or ion accelerator methods. Use of an ERL enables increased energy efficiency of the complex through energy recovery of the waste electron beam, high electron currents for high production yields, and reduced neutron production and shielding activation at beam dump components. Simulation studies using G4Beamline/GEANT4 and MCNP6 through MuSim, as well as other simulation codes, will design an ERL-based isotope production facility utilizing bremsstrahlung photon beams from an electron linac. Balancing the isotope production parameters versus energy recovery requirements will inform a choice of isotope production target for future experiments.

  15. Cyclotron Production of Medical Radioisotopes

    SciTech Connect

    Avila-Rodriguez, M. A.; Zarate-Morales, A.; Flores-Moreno, A.

    2010-08-04

    The cyclotron production of radioisotopes for medical applications is gaining increased significance in diagnostic molecular imaging techniques such as PET and SPECT. In this regard, radioisotope production has never been easier or more convenient until de introduction of compact medical cyclotrons in the last few decades, which allowed the use of short-lived radioisotopes in in vivo nuclear medicine studies on a routine basis. This review outlines some general considerations about the production of radioisotopes using charged particle accelerators.

  16. Planetary Protection Concerns During Pre-Launch Radioisotope Power System Final Integration Activities

    NASA Technical Reports Server (NTRS)

    Chen, Fei; McKay, Terri; Spry, James A.; Colozza, Anthony J.; DiStefano, Salvador

    2012-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a next-generation radioisotope-based power system that is currently being developed as an alternative to the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). Power sources such as these may be needed for proposed missions to solar system planets and bodies that have challenging Planetary Protection (PP) requirements (e.g. Mars, Europa, Enceladus) that may support NASA s search for life, remnants of past life, and the precursors of life. One concern is that the heat from the ASRG could potentially create a region in which liquid water may occur. As advised by the NASA Planetary Protection Officer, when deploying an ASRG to Mars, the current COSPAR/NASA PP policy should be followed for Category IVc mission. Thus, sterilization processing of the ASRG to achieve bioburden reduction would be essential to meet the Planetary Protection requirements. Due to thermal constraints and associated low temperature limits of elements of the ASRG, vapor hydrogen peroxide (VHP) was suggested as a candidate alternative sterilization process to complement dry heat microbial reduction (DHMR) for the assembled ASRG. The following proposed sterilization plan for the ASRG anticipates a mission Category IVc level of cleanliness. This plan provides a scenario in which VHP is used as the final sterilization process. Keywords: Advanced Stirling Radioisotope Generator (ASRG), Planetary Protection (PP), Vapor hydrogen peroxide (VHP) sterilization.

  17. Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m

    SciTech Connect

    2010-01-01

    Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

  18. Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m

    ScienceCinema

    None

    2013-05-28

    Accelerator Generation and Thermal Separation (AGATS) of Technetium-99m is a linear electron accelerator-based technology for producing medical imaging radioisotopes from a separation process that heats, vaporizes and condenses the desired radioisotope. You can learn more about INL's education programs at http://www.facebook.com/idahonationallaboratory.

  19. Taming Highly Charged Radioisotopes

    NASA Astrophysics Data System (ADS)

    Chowdhury, Usman; Eberhardt, Benjamin; Jang, Fuluni; Schultz, Brad; Simon, Vanessa; Delheij, Paul; Dilling, Jens; Gwinner, Gerald

    2012-10-01

    The precise and accurate mass of short-lived radioisotopes is a very important parameter in physics. Contribution to the improvement of nuclear models, metrological standard fixing and tests of the unitarity of the Caibbibo-Kobayashi-Maskawa (CKM) matrix are a few examples where the mass value plays a major role. TRIUMF's ion trap for atomic and nuclear physics (TITAN) is a unique facility of three online ion traps that enables the mass measurement of short-lived isotopes with high precision (˜10-8). At present TITAN's electron beam ion trap (EBIT) increases the charge state to increase the precision, but there is no facility to significantly reduce the energy spread introduced by the charge breeding process. The precision of the measured mass of radioisotopes is linearly dependent on the charge state while the energy spread of the charged radioisotopes affects the precision adversely. To boost the precision level of mass measurement at TITAN without loosing too many ions, a cooler Penning trap (CPET) is being developed. CPET is designed to use either positively (proton) or negatively (electron) charged particles to reduce the energy spread via sympathetic cooling. Off-line setup of CPET is complete. Details of the working principles and updates are presented

  20. NASA's Radioisotope Power Systems - Plans

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; Mccallum, Peter W.; Sandifer, Carl E., II; Sutliff, Thomas J.; Zakrajsek, June F.

    2015-01-01

    NASA's Radioisotope Power Systems (RPS) Program continues to plan and implement content to enable planetary exploration where such systems could be needed, and to prepare more advanced RPS technology for possible infusion into future power systems. The 2014-2015 period saw significant changes, and strong progress. Achievements of near-term objectives have enabled definition of a clear path forward in which payoffs from research investments and other sustaining efforts can be applied. The future implementation path is expected to yield a higher-performing thermoelectric generator design, a more isotope-fuel efficient system concept design, and a robust RPS infrastructure maintained effectively within both NASA and the Department of Energy. This paper describes recent work with an eye towards the future plans that result from these achievements.

  1. Miniature Radioisotope Thermoelectric Power Cubes

    NASA Technical Reports Server (NTRS)

    Patel, Jagdish U.; Fleurial, Jean-Pierre; Snyder, G. Jeffrey; Caillat, Thierry

    2004-01-01

    Cube-shaped thermoelectric devices energized by a particles from radioactive decay of Cm-244 have been proposed as long-lived sources of power. These power cubes are intended especially for incorporation into electronic circuits that must operate in dark, extremely cold locations (e.g., polar locations or deep underwater on Earth, or in deep interplanetary space). Unlike conventional radioisotope thermoelectric generators used heretofore as central power sources in some spacecraft, the proposed power cubes would be small enough (volumes would range between 0.1 and 0.2 cm3) to play the roles of batteries that are parts of, and dedicated to, individual electronic-circuit packages. Unlike electrochemical batteries, these power cubes would perform well at low temperatures. They would also last much longer: given that the half-life of Cm-244 is 18 years, a power cube could remain adequate as a power source for years, depending on the power demand in its particular application.

  2. Advanced Radioisotope Power Conversion Technology Research and Development

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2004-01-01

    NASA's Radioisotope Power Conversion Technology program is developing next generation power conversion technologies that will enable future missions that have requirements that cannot be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power System (RPS) technology. Performance goals of advanced radioisotope power systems include improvement over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. NASA has awarded ten contracts in the technology areas of Brayton, Stirling, Thermoelectric, and Thermophotovoltaic power conversion including five development contracts that deal with more mature technologies and five research contracts. The Advanced RPS Systems Assessment Team includes members from NASA GRC, JPL, DOE and Orbital Sciences whose function is to review the technologies being developed under the ten Radioisotope Power Conversion Technology contracts and assess their relevance to NASA's future missions. Presented is an overview of the ten radioisotope power conversion technology contracts and NASA's Advanced RPS Systems Assessment Team.

  3. NASA Radioisotope Power Conversion Technology NRA Overview

    NASA Technical Reports Server (NTRS)

    Anderson, David J.

    2005-01-01

    The focus of the National Aeronautics and Space Administration s (NASA) Radioisotope Power Systems (RPS) Development program is aimed at developing nuclear power and technologies that would improve the effectiveness of space science missions. The Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) is an important mechanism through which research and technology activities are supported in the Advanced Power Conversion Research and Technology project of the Advanced Radioisotope Power Systems Development program. The purpose of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide higher efficiencies and specific powers than existing systems. These advances would enable a factor of 2 to 4 decrease in the amount of fuel and a reduction of waste heat required to generate electrical power, and thus could result in more cost effective science missions for NASA. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100We scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, a summary of the power conversion technologies approaches being pursued, and a brief digest of first year accomplishments.

  4. NASA Radioisotope Power Conversion Technology NRA Overview

    NASA Technical Reports Server (NTRS)

    Anderson, David J.

    2005-01-01

    The focus of the National Aeronautics and Space Administration's (NASA) Radioisotope Power Systems (RPS) Development program is aimed at developing nuclear power and technologies that would improve the effectiveness of space science missions. The Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) is an important mechanism through which research and technology activities are supported in the Advanced Power Conversion Research and Technology project of the Advanced Radioisotope Power Systems Development program. The purpose of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide higher efficiencies and specific powers than existing systems. These advances would enable a factor of two to four decrease in the amount of fuel and a reduction of waste heat required to generate electrical power, and thus could result in more cost effective science missions for NASA. The RPCT NRA selected advanced RPS power conversion technology research and development proposals in the following three areas: innovative RPS power conversion research, RPS power conversion technology development in a nominal 100 W(sub e) scale; and, milliwatt/multi-watt RPS (mWRPS) power conversion research. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, a summary of the power conversion technologies approaches being pursued, and a brief digest of first year accomplishments.

  5. Work Began on Contracts for Radioisotope Power Conversion Technology Research and Development

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2005-01-01

    NASA has had a history of successful space flight missions that depended on radioisotope-fueled power systems. These Radioisotope Power Systems (RPSs) converted the heat generated from the decay of radioisotope material into useful electrical power. An RPS is most attractive in applications where photovoltaics are not optimal, such as deep-space applications where the solar flux is too low or extended applications on planets such as Mars where the day/night cycle, settling of dust, and life requirements limit the usefulness of photovoltaics. NASA s Radioisotope Power Conversion Technology (RPCT) Program is developing next-generation power-conversion technologies that will enable future missions that have requirements that cannot be met by the two RPS flight systems currently being developed by the Department of Energy for NASA: the Multi-Mission Radioisotope Thermoelectric Generator and the Stirling Radioisotope Generator (SRG).

  6. Radioisotope electric propulsion for robotic science missions to near-interstellar space

    SciTech Connect

    Noble, R.J.

    1994-10-01

    The use of radioisotope electric propulsion for sending small robotic probes on fast science missions several hundred astronomical units (AU) from the Sun is investigated. Such missions would address a large variety of solar, interstellar, galactic and cosmological science themes from unique vantage points at 100 to 600 AU, including parallax distance measurements for the entire Milky Way Galaxy, sampling of the interstellar medium and imaging of cosmological objects at the gravitational lens foci of the Sun ({ge} 550 AU). Radioisotope electric propulsion (REP) systems are low-thrust, ion propulsion units based on multi-hundred watt, radioisotope electric generators and ion thrusters. In a previous work, the flight times for rendezvous missions to the outer planets (< 30 AU) using REP were found to be less than fifteen years. However fast prestellar missions to several hundred AU are not possible unless the probe`s energy can be substantially increased in the inner Solar System so as to boost the final hyperbolic excess velocity. In this paper an economical hybrid propulsion scheme combining chemical propulsion and gravity assist in the inner Solar System and radioisotope electric propulsion in the outer Solar System is studied which enables fast prestellar missions. Total hyperbolic excess velocities of 15 AU/year and flight times to 550 AU of about 40 years are possible using REP technology that may be available in the next decade.

  7. Alternative Radioisotopes for Heat and Power Sources

    NASA Astrophysics Data System (ADS)

    Tinsley, T.; Sarsfield, M.; Rice, T.

    Production of 238Pu requires considerable facilities including a nuclear reactor and reprocessing plants that are very expensive to build and operate. Thus, a more economical alternative is very attractive to the industry. There are many alternative radioisotopes that exist but few that satisfy the criteria of performance, availability and cost to produce. Any alternative to 238Pu must exist in a chemical form that is compatible with the materials required to safely encapsulate the heat source at the high temperatures of operation and potential launch failure scenarios. The chemical form must also have suitable thermal properties to ensure maximum energy conversion efficiencies when integrated into radioisotope thermoelectric generators over the required mission durations. In addition, the radiation dose must be low enough for operators during production and not so prohibitive that excessive shielding mass is required on the space craft. This paper will focus on the preferred European alternative of 241Am, and the issues that will need to be addressed.

  8. A 5 MW TRIGA reactor design for radioisotope production

    SciTech Connect

    Veca, Anthony R.; Whittemore, William L.

    1994-07-01

    The production and preparation of commercial-scale quantities of radioisotopes has become an important activity as their medical and industrial applications continue to expand. There are currently various large multipurpose research reactors capable of producing ample quantities of radioisotopes. These facilities, however, have many competing demands placed upon them by a wide variety of researchers and scientific programs which severely limit their radioisotope production capability. A demonstrated need has developed for a simpler reactor facility dedicated to the production of radioisotopes on a commercial basis. This smaller, dedicated reactor could provide continuous fission and activation product radioisotopes to meet commercial requirements for the foreseeable future. The design of a 5 MW TRIGA reactor facility, upgradeable to 10 MW, dedicated to the production of industrial and medical radioisotopes is discussed. A TRIGA reactor designed specifically for this purpose with its demonstrated long core life and simplicity of operation would translate into increased radioisotope production. As an example, a single TRIGA could supply the entire US needs for Mo-99. The facility is based on the experience gained by General Atomics in the design, installation, and construction of over 60 other TRIGAs over the past 35 years. The unique uranium-zirconium hydride fuel makes TRIGA reactors inexpensive to build and operate, reliable in their simplicity, highly flexible due to unique passive safety, and environmentally friendly because of minimal power requirements and long-lived fuel. (author)

  9. Performance tuned radioisotope thermophotovoltaic space power system

    NASA Astrophysics Data System (ADS)

    Horne, W. E.; Morgan, M. D.; Saban, S. B.

    1998-01-01

    The trend in space exploration is to use many small, low-cost, special-purpose satellites instead of the large, high-cost, multipurpose satellites used in the past. As a result of this new trend, there is a need for lightweight, efficient, and compact radioisotope fueled electrical power generators. This paper presents an improved design for a radioisotope thermophotovoltaic (RTPV) space power system in the 10 W to 20 W class which promises up to 37.6 watts at 30.1% efficiency and 25 W/kg specific power. The RTPV power system concept has been studied and compared to radioisotope thermoelectric generators (RTG) radioisotope, Stirling generators and alkali metal thermal electric conversion (AMTEC) generators (Schock, 1995). The studies indicate that RTPV has the potential to be the lightest weight, most efficient and most reliable of the three concepts. However, in spite of the efficiency and light weight, the size of the thermal radiator required to eliminate excess heat from the PV cells and the lack of actual system operational performance data are perceived as obstacles to RTPV acceptance for space applications. Between 1994 and 1997 EDTEK optimized the key converter components for an RTPV generator under Department of Energy (DOE) funding administered via subcontracts to Orbital Sciences Corporation (OSC) and EG&G Mound Applied Technologies Laboratory (Horne, 1995). The optimized components included a resonant micromesh infrared bandpass filter, low-bandgap GaSb PV cells and cell arrays. Parametric data from these components were supplied to OSC who developed and analyzed the performance of 100 W, 20 W, and 10 W RTPV generators. These designs are described in references (Schock 1994, 1995 and 1996). Since the performance of each class of supply was roughly equivalent and simply scaled with size, this paper will consider the OSC 20 W design as a baseline. The baseline 20-W RTPV design was developed by Schock, et al of OSC and has been presented elsewhere. The

  10. A Simple Model for Radioisotope Power System Performance in the Titan Environment

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.

    Like other energy conversion devices, the performance of Radioisotope Power Systems (RPSs) for spacecraft depend on the heat transfer boundary conditions. In planetary environments, the heat transfer, and thus the RPS operating conditions and performance may be different from those in free space. In particular, we develop a simple model (based on an endoreversible heat engine with a specified heat sink) for the performance of an Advanced Stirling Radioisotope Generator (ASRG) in the dense, cold atmosphere of Titan. We find the power output of an ideal RPS in the Titan environment could be considerably superior to that in space vacuum, although an internal heat leak of the present ASRG design may somewhat compromise this improvement, resulting in an output close to, or up to 15% smaller than, predicted vacuum output. Since the model suggests significant variation due to two competing effects, performance testing in representative conditions is urgently recommended.

  11. NASA's Advanced Radioisotope Power Conversion Technology Development Status

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Sankovic, John; Wilt, David; Abelson, Robert D.; Fleurial, Jean-Pierre

    2007-01-01

    NASA's Advanced Radioisotope Power Systems (ARPS) project is developing the next generation of radioisotope power conversion technologies that will enable future missions that have requirements that cannot be met by either photovoltaic systems or by current radioisotope power systems (RPSs). Requirements of advanced RPSs include high efficiency and high specific power (watts/kilogram) in order to meet future mission requirements with less radioisotope fuel and lower mass so that these systems can meet requirements for a variety of future space applications, including continual operation surface missions, outer-planetary missions, and solar probe. These advances would enable a factor of 2 to 4 decrease in the amount of fuel required to generate electrical power. Advanced RPS development goals also include long-life, reliability, and scalability. This paper provides an update on the contractual efforts under the Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) for research and development of Stirling, thermoelectric, and thermophotovoltaic power conversion technologies. The paper summarizes the current RPCT NRA efforts with a brief description of the effort, a status and/or summary of the contractor's key accomplishments, a discussion of upcoming plans, and a discussion of relevant system-level benefits and implications. The paper also provides a general discussion of the benefits from the development of these advanced power conversion technologies and the eventual payoffs to future missions (discussing system benefits due to overall improvements in efficiency, specific power, etc.).

  12. Simulation-Based Rule Generation Considering Readability

    PubMed Central

    Yahagi, H.; Shimizu, S.; Ogata, T.; Hara, T.; Ota, J.

    2015-01-01

    Rule generation method is proposed for an aircraft control problem in an airport. Designing appropriate rules for motion coordination of taxiing aircraft in the airport is important, which is conducted by ground control. However, previous studies did not consider readability of rules, which is important because it should be operated and maintained by humans. Therefore, in this study, using the indicator of readability, we propose a method of rule generation based on parallel algorithm discovery and orchestration (PADO). By applying our proposed method to the aircraft control problem, the proposed algorithm can generate more readable and more robust rules and is found to be superior to previous methods. PMID:27347501

  13. Simulation-Based Rule Generation Considering Readability.

    PubMed

    Yahagi, H; Shimizu, S; Ogata, T; Hara, T; Ota, J

    2015-01-01

    Rule generation method is proposed for an aircraft control problem in an airport. Designing appropriate rules for motion coordination of taxiing aircraft in the airport is important, which is conducted by ground control. However, previous studies did not consider readability of rules, which is important because it should be operated and maintained by humans. Therefore, in this study, using the indicator of readability, we propose a method of rule generation based on parallel algorithm discovery and orchestration (PADO). By applying our proposed method to the aircraft control problem, the proposed algorithm can generate more readable and more robust rules and is found to be superior to previous methods. PMID:27347501

  14. Error Generation in CATS-Based Agents

    NASA Technical Reports Server (NTRS)

    Callantine, Todd

    2003-01-01

    This research presents a methodology for generating errors from a model of nominally preferred correct operator activities, given a particular operational context, and maintaining an explicit link to the erroneous contextual information to support analyses. It uses the Crew Activity Tracking System (CATS) model as the basis for error generation. This report describes how the process works, and how it may be useful for supporting agent-based system safety analyses. The report presents results obtained by applying the error-generation process and discusses implementation issues. The research is supported by the System-Wide Accident Prevention Element of the NASA Aviation Safety Program.

  15. Ontology-Based Multiple Choice Question Generation

    PubMed Central

    Al-Yahya, Maha

    2014-01-01

    With recent advancements in Semantic Web technologies, a new trend in MCQ item generation has emerged through the use of ontologies. Ontologies are knowledge representation structures that formally describe entities in a domain and their relationships, thus enabling automated inference and reasoning. Ontology-based MCQ item generation is still in its infancy, but substantial research efforts are being made in the field. However, the applicability of these models for use in an educational setting has not been thoroughly evaluated. In this paper, we present an experimental evaluation of an ontology-based MCQ item generation system known as OntoQue. The evaluation was conducted using two different domain ontologies. The findings of this study show that ontology-based MCQ generation systems produce satisfactory MCQ items to a certain extent. However, the evaluation also revealed a number of shortcomings with current ontology-based MCQ item generation systems with regard to the educational significance of an automatically constructed MCQ item, the knowledge level it addresses, and its language structure. Furthermore, for the task to be successful in producing high-quality MCQ items for learning assessments, this study suggests a novel, holistic view that incorporates learning content, learning objectives, lexical knowledge, and scenarios into a single cohesive framework. PMID:24982937

  16. Ontology-based multiple choice question generation.

    PubMed

    Al-Yahya, Maha

    2014-01-01

    With recent advancements in Semantic Web technologies, a new trend in MCQ item generation has emerged through the use of ontologies. Ontologies are knowledge representation structures that formally describe entities in a domain and their relationships, thus enabling automated inference and reasoning. Ontology-based MCQ item generation is still in its infancy, but substantial research efforts are being made in the field. However, the applicability of these models for use in an educational setting has not been thoroughly evaluated. In this paper, we present an experimental evaluation of an ontology-based MCQ item generation system known as OntoQue. The evaluation was conducted using two different domain ontologies. The findings of this study show that ontology-based MCQ generation systems produce satisfactory MCQ items to a certain extent. However, the evaluation also revealed a number of shortcomings with current ontology-based MCQ item generation systems with regard to the educational significance of an automatically constructed MCQ item, the knowledge level it addresses, and its language structure. Furthermore, for the task to be successful in producing high-quality MCQ items for learning assessments, this study suggests a novel, holistic view that incorporates learning content, learning objectives, lexical knowledge, and scenarios into a single cohesive framework. PMID:24982937

  17. Coal based electric generation comparative technologies report

    SciTech Connect

    Not Available

    1989-10-26

    Ohio Clean Fuels, Inc., (OCF) has licensed technology that involves Co-Processing (Co-Pro) poor grade (high sulfur) coal and residual oil feedstocks to produce clean liquid fuels on a commercial scale. Stone Webster is requested to perform a comparative technologies report for grassroot plants utilizing coal as a base fuel. In the case of Co-Processing technology the plant considered is the nth plant in a series of applications. This report presents the results of an economic comparison of this technology with other power generation technologies that use coal. Technologies evaluated were:Co-Processing integrated with simple cycle combustion turbine generators, (CSC); Co-Processing integrated with combined cycle combustion turbine generators, (CCC); pulverized coal-fired boiler with flue gas desulfurization and steam turbine generator, (PC) and Circulating fluidized bed boiler and steam turbine generator, (CFB). Conceptual designs were developed. Designs were based on approximately equivalent net electrical output for each technology. A base case of 310 MWe net for each technology was established. Sensitivity analyses at other net electrical output sizes varying from 220 MWe's to 1770 MWe's were also performed. 4 figs., 9 tabs.

  18. How to Handle Radioisotopes Safely.

    ERIC Educational Resources Information Center

    Sulcoski, John W.

    This booklet is one in a series of instructional aids designed for use by elementary and secondary school science teachers. The various units and forms of radioactive materials used by teachers are first considered. Then, the quantities of radioisotopes that a person may possess without a license from the Atomic Energy Commission (AEC) are…

  19. Radioisotope Thermoelectric Generators (RTGs) for Lunar Exploration

    NASA Astrophysics Data System (ADS)

    Woerner, D. F.

    2014-10-01

    A Multi-Mission RTG (MMRTG) is powering the Curiosity rover and was designed as a compact, rugged power source capable of landing on other bodies. NASA is considering development of an enhanced MMRTG and Advanced RTG. More info presented here.

  20. Design Study: Rocket Based MHD Generator

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This report addresses the technical feasibility and design of a rocket based MHD generator using a sub-scale LOx/RP rocket motor. The design study was constrained by assuming the generator must function within the performance and structural limits of an existing magnet and by assuming realistic limits on (1) the axial electric field, (2) the Hall parameter, (3) current density, and (4) heat flux (given the criteria of heat sink operation). The major results of the work are summarized as follows: (1) A Faraday type of generator with rectangular cross section is designed to operate with a combustor pressure of 300 psi. Based on a magnetic field strength of 1.5 Tesla, the electrical power output from this generator is estimated to be 54.2 KW with potassium seed (weight fraction 3.74%) and 92 KW with cesium seed (weight fraction 9.66%). The former corresponds to a enthalpy extraction ratio of 2.36% while that for the latter is 4.16%; (2) A conceptual design of the Faraday MHD channel is proposed, based on a maximum operating time of 10 to 15 seconds. This concept utilizes a phenolic back wall for inserting the electrodes and inter-electrode insulators. Copper electrode and aluminum oxide insulator are suggested for this channel; and (3) A testing configuration for the sub-scale rocket based MHD system is proposed. An estimate of performance of an ideal rocket based MHD accelerator is performed. With a current density constraint of 5 Amps/cm(exp 2) and a conductivity of 30 Siemens/m, the push power density can be 250, 431, and 750 MW/m(sup 3) when the induced voltage uB have values of 5, 10, and 15 KV/m, respectively.

  1. Radioisotope Power Systems Program: A Program Overview

    NASA Technical Reports Server (NTRS)

    Hamley, John A.

    2016-01-01

    NASA's Radioisotope Power Systems (RPS) Program continues to plan, mature research in energy conversion, and partners with the Department of Energy (DOE) to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet potential future mission needs. Recent programs responsibilities include providing investment recommendations to NASA stakeholders on emerging thermoelectric and Stirling energy conversion technologies and insight on NASA investments at DOE in readying a generator for the Mars 2020 mission. This presentation provides an overview of the RPS Program content and status and the approach used to maintain the readiness of RPS to support potential future NASA missions.

  2. Effect of Inert Cover Gas on Performance of Radioisotope Stirling Space Power System

    SciTech Connect

    Carpenter, Robert; Kumar, V; Ore, C; Schock, Alfred

    2001-01-01

    This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Company (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al. 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission.

  3. Effect of inert cover gas on performance of radioisotope Stirling space power system

    NASA Astrophysics Data System (ADS)

    Carpenter, R.; Kumar, V.; Or, C.; Schock, A.

    2001-02-01

    This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched on missions to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Company (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al., 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission. .

  4. Preparing for Harvesting Radioisotopes from FRIB

    SciTech Connect

    Peaslee, Graham F.; Lapi, Suzanne E.

    2015-02-02

    The Facility for Rare Isotope Beams (FRIB) is the next generation accelerator facility under construction at Michigan State University. FRIB will produce a wide variety of rare isotopes by a process called projectile fragmentation for a broad range of new experiments when it comes online in 2020. The accelerated rare isotope beams produced in this facility will be more intense than any current facility in the world - in many cases by more than 1000-fold. These beams will be available to the primary users of FRIB in order to do exciting new fundamental research with accelerated heavy ions. In the standard mode of operation, this will mean one radioisotope will be selected at a time for the user. However, the projectile fragmentation process also yields hundreds of other radioisotopes at these bombarding energies, and many of these rare isotopes are long-lived and could have practical applications in medicine, national security or the environment. This project developed new methods to collect these long-lived rare isotopes that are by-products of the standard FRIB operation. These isotopes are important to many areas of research, thus this project will have a broad impact in several scientific areas including medicine, environment and homeland security.

  5. Reliability Issues in Stirling Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Shah, Ashwin R.; Schreiber, Jeffrey G.

    2004-01-01

    Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive material. Reliability of an RPS that utilizes Stirling power conversion technology is important in order to ascertain long term successful performance. Owing to long life time requirement (14 years), it is difficult to perform long-term tests that encompass all the uncertainties involved in the design variables of components and subsystems comprising the RPS. The requirement for uninterrupted performance reliability and related issues are discussed, and some of the critical areas of concern are identified. An overview of the current on-going efforts to understand component life, design variables at the component and system levels, and related sources and nature of uncertainties are also discussed. Current status of the 110 watt Stirling Radioisotope Generator (SRG110) reliability efforts is described. Additionally, an approach showing the use of past experience on other successfully used power systems to develop a reliability plan for the SRG110 design is outlined.

  6. Reliability Issues in Stirling Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey; Shah, Ashwin

    2005-01-01

    Stirling power conversion is a potential candidate for use in a Radioisotope Power System (RPS) for space science missions because it offers a multifold increase in the conversion efficiency of heat to electric power and reduced requirement of radioactive material. Reliability of an RPS that utilizes Stirling power conversion technology is important in order to ascertain long term successful performance. Owing to long life time requirement (14 years), it is difficult to perform long-term tests that encompass all the uncertainties involved in the design variables of components and subsystems comprising the RPS. The requirement for uninterrupted performance reliability and related issues are discussed, and some of the critical areas of concern are identified. An overview of the current on-going efforts to understand component life, design variables at the component and system levels, and related sources and nature of uncertainties are also discussed. Current status of the 110 watt Stirling Radioisotope Generator (SRG110) reliability efforts is described. Additionally, an approach showing the use of past experience on other successfully used power systems to develop a reliability plan for the SRG110 design is outlined.

  7. Statistical filtering for NMR based structure generation

    PubMed Central

    2011-01-01

    The constitutional assignment of natural products by NMR spectroscopy is usually based on 2D NMR experiments like COSY, HSQC, and HMBC. The difficulty of a structure elucidation problem depends more on the type of the investigated molecule than on its size. Saturated compounds can usually be assigned unambiguously by hand using only COSY and 13C-HMBC data, whereas condensed heterocycles are problematic due to their lack of protons that could show interatomic connectivities. Different computer programs were developed to aid in the structural assignment process, one of them COCON. In the case of unsaturated and substituted molecules structure generators frequently will generate a very large number of possible solutions. This article presents a "statistical filter" for the reduction of the number of results. The filter works by generating 3D conformations using smi23d, a simple MD approach. All molecules for which the generation of constitutional restraints failed were eliminated from the result set. Some structural elements removed by the statistical filter were analyzed and checked against Beilstein. The automatic removal of molecules for which no MD parameter set could be created was included into WEBCOCON. The effect of this filter varies in dependence of the NMR data set used, but in no case the correct constitution was removed from the resulting set. PMID:21835037

  8. HFIR-produced medical radioisotopes

    SciTech Connect

    Mirzadeh, S.; Knapp, F.F. Jr.; Beets, A.L.; Alexander, C.W.

    1997-12-01

    We have experimentally determined the yields of a number of medical radioisotopes produced in the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR) Hydraulic Tube (HT) facility. The HT facility is located in the very high flux region in the flux trap of the reactor, providing on-line access capability while the reactor is operating. The HT facility consists of nine vertically stacked capsules centered just adjacent to the core horizontal midplane. HFIR operates at a nominal power level of 85 MW. The capabilities of the HFIR-HT facilities offer increased efficiency, greater availability, and optimization of radioisotope production, and, as a result, the conservation of rare or expensive target isotopes.

  9. Efficiency of Pm-147 direct charge radioisotope battery.

    PubMed

    Kavetskiy, A; Yakubova, G; Yousaf, S M; Bower, K; Robertson, J D; Garnov, A

    2011-05-01

    A theoretical analysis is presented here of the efficiency of direct charge radioisotope batteries based on the efficiency of the radioactive source, the system geometry, electrostatic repulsion of beta particles from the collector, the secondary electron emission, and backscattered beta particles from the collector. Efficiency of various design batteries using Pm-147 sources was experimentally measured and found to be in good agreement with calculations. The present approach can be used for predicting the efficiency for different designs of direct charge radioisotope batteries. PMID:21295487

  10. Virus-based piezoelectric energy generation

    NASA Astrophysics Data System (ADS)

    Lee, Byung Yang; Zhang, Jinxing; Zueger, Chris; Chung, Woo-Jae; Yoo, So Young; Wang, Eddie; Meyer, Joel; Ramesh, Ramamoorthy; Lee, Seung-Wuk

    2012-06-01

    Piezoelectric materials can convert mechanical energy into electrical energy, and piezoelectric devices made of a variety of inorganic materials and organic polymers have been demonstrated. However, synthesizing such materials often requires toxic starting compounds, harsh conditions and/or complex procedures. Previously, it was shown that hierarchically organized natural materials such as bones, collagen fibrils and peptide nanotubes can display piezoelectric properties. Here, we demonstrate that the piezoelectric and liquid-crystalline properties of M13 bacteriophage (phage) can be used to generate electrical energy. Using piezoresponse force microscopy, we characterize the structure-dependent piezoelectric properties of the phage at the molecular level. We then show that self-assembled thin films of phage can exhibit piezoelectric strengths of up to 7.8 pm V-1. We also demonstrate that it is possible to modulate the dipole strength of the phage, hence tuning the piezoelectric response, by genetically engineering the major coat proteins of the phage. Finally, we develop a phage-based piezoelectric generator that produces up to 6 nA of current and 400 mV of potential and use it to operate a liquid-crystal display. Because biotechnology techniques enable large-scale production of genetically modified phages, phage-based piezoelectric materials potentially offer a simple and environmentally friendly approach to piezoelectric energy generation.

  11. Investigation of Insulation Materials for Future Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power Systems (RPS) Technology Advancement Project is developing next generation high-temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  12. Investigation of Insulation Materials for Future Radioisotope Power Systems (RPS)

    NASA Technical Reports Server (NTRS)

    Cornell, Peggy A.; Hurwitz, Frances I.; Ellis, David L.; Schmitz, Paul C.

    2013-01-01

    NASA's Radioisotope Power System (RPS) Technology Advancement Project is developing next generation high temperature insulation materials that directly benefit thermal management and improve performance of RPS for future science missions. Preliminary studies on the use of multilayer insulation (MLI) for Stirling convertors used on the Advanced Stirling Radioisotope Generator (ASRG) have shown the potential benefits of MLI for space vacuum applications in reducing generator size and increasing specific power (W/kg) as compared to the baseline Microtherm HT (Microtherm, Inc.) insulation. Further studies are currently being conducted at NASA Glenn Research Center (GRC) on candidate MLI foils and aerogel composite spacers. This paper presents the method of testing of foils and spacers and experimental results to date.

  13. An Overview and Status of NASA's Radioisotope Power Conversion Technology NRA

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Wong, Wayne A.; Tuttle, Karen L.

    2005-01-01

    NASA's Advanced Radioisotope Power Systems (RPS) development program is developing next generation radioisotope power conversion technologies that will enable future missions that have requirements that can not be met by either photovoltaic systems or by current Radioisotope Power System (RPS) technology. The Advanced Power Conversion Research and Technology project of the Advanced RPS development program is funding research and technology activities through the NASA Research Announcement (NRA) 02-OSS-01, "Research Opportunities in Space Science 2002" entitled "Radioisotope Power Conversion Technology" (RPCT), August 13, 2002. The objective of the RPCT NRA is to advance the development of radioisotope power conversion technologies to provide significant improvements over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. Ten RPCT NRA contracts were awarded in 2003 in the areas of Brayton, Stirling, thermoelectric (TE), and thermophotovoltaic (TPV) power conversion technologies. This paper will provide an overview of the RPCT NRA, and a brief summary of accomplishments over the first 18 months but focusing on advancements made over the last 6 months.

  14. List of DOE radioisotope customers with summary of radioisotope shipments, FY 1985

    SciTech Connect

    Baker, D.A.

    1986-08-01

    This document describes radioisotope distribution from DOE facilities to private firms including foreign and other DOE facilities. The information is divided into five sections: (1) isotope suppliers, facility contacts, and isotopes or services supplied; (2) customers, suppliers, and isotopes purchased; (3) isotopes purchased cross-referenced with customer numbers; (4) geographic locations of radioisotope customers; and (5) radioisotope sales and transfer - FY 1985.

  15. NASA's Radioisotope Power Systems Planning and Potential Future Systems Overview

    NASA Technical Reports Server (NTRS)

    Zakrajsek, June F.; Woerner, Dave F.; Cairns-Gallimore, Dirk; Johnson, Stephen G.; Qualls, Louis

    2016-01-01

    The goal of NASA's Radioisotope Power Systems (RPS) Program is to make RPS ready and available to support the exploration of the solar system in environments where the use of conventional solar or chemical power generation is impractical or impossible to meet the needs of the missions. To meet this goal, the RPS Program, working closely with the Department of Energy, performs mission and system studies (such as the recently released Nuclear Power Assessment Study), assesses the readiness of promising technologies to infuse in future generators, assesses the sustainment of key RPS capabilities and knowledge, forecasts and tracks the Program's budgetary needs, and disseminates current information about RPS to the community of potential users. This process has been refined and used to determine the current content of the RPS Program's portfolio. This portfolio currently includes an effort to mature advanced thermoelectric technology for possible integration into an enhanced Multi-Mission Radioisotope Generator (eMMRTG), sustainment and production of the currently deployed MMRTG, and technology investments that could lead to a future Stirling Radioisotope Generator (SRG). This paper describes the program planning processes that have been used, the currently available MMRTG, and one of the potential future systems, the eMMRTG.

  16. A liquid xenon radioisotope camera.

    NASA Technical Reports Server (NTRS)

    Zaklad, H.; Derenzo, S. E.; Muller, R. A.; Smadja, G.; Smits, R. G.; Alvarez, L. W.

    1972-01-01

    A new type of gamma-ray camera is discussed that makes use of electron avalanches in liquid xenon and is currently under development. It is shown that such a radioisotope camera promises many advantages over any other existing gamma-ray cameras. Spatial resolution better than 1 mm and counting rates higher than one million C/sec are possible. An energy resolution of 11% FWHM has recently been achieved with a collimated Hg-203 source using a parallel-plate ionization chamber containing a Frisch grid.

  17. Production capabilities in US nuclear reactors for medical radioisotopes

    SciTech Connect

    Mirzadeh, S.; Callahan, A.P.; Knapp, F.F. Jr.; Schenter, R.E.

    1992-11-01

    The availability of reactor-produced radioisotopes in the United States for use in medical research and nuclear medicine has traditionally depended on facilities which are an integral part of the US national laboratories and a few reactors at universities. One exception is the reactor in Sterling Forest, New York, originally operated as part of the Cintichem (Union Carbide) system, which is currently in the process of permanent shutdown. Since there are no industry-run reactors in the US, the national laboratories and universities thus play a critical role in providing reactor-produced radioisotopes for medical research and clinical use. The goal of this survey is to provide a comprehensive summary of these production capabilities. With the temporary shutdown of the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) in November 1986, the radioisotopes required for DOE-supported radionuclide generators were made available at the Brookhaven National Laboratory (BNL) High Flux Beam Reactor (HFBR). In March 1988, however, the HFBR was temporarily shut down which forced investigators to look at other reactors for production of the radioisotopes. During this period the Missouri University Research Reactor (MURR) played an important role in providing these services. The HFIR resumed routine operation in July 1990 at 85 MW power, and the HFBR resumed operation in June 1991, at 30 MW power. At the time of the HFBR shutdown, there was no available comprehensive overview which could provide information on status of the reactors operating in the US and their capabilities for radioisotope production. The obvious need for a useful overview was thus the impetus for preparing this survey, which would provide an up-to-date summary of those reactors available in the US at both the DOE-funded national laboratories and at US universities where service irradiations are currently or expected to be conducted.

  18. A rainfall simulator based on multifractal generator

    NASA Astrophysics Data System (ADS)

    Akrour, Nawal; mallet, Cecile; barthes, Laurent; chazottes, Aymeric

    2015-04-01

    The Precipitations are due to complex meteorological phenomenon's and unlike other geophysical constituents such as water vapour concentration they present a relaxation behaviour leading to an alternation of dry and wet periods. Thus, precipitations can be described as intermittent process. The spatial and temporal variability of this phenomenon is significant and covers large scales. This high variability can cause extreme events which are difficult to observe properly because of their suddenness and their localized character. For all these reasons, the precipitations are therefore difficult to model. This study aims to adapt a one-dimensional time series model previously developed by the authors [Akrour et al., 2013, 2014] to a two-dimensional rainfall generator. The original time series model can be divided into 3 major steps : rain support generation, intra event rain rates generation using multifractal and finally calibration process. We use the same kind of methodology in the present study. Based on dataset obtained from meteorological radar of Météo France with a spatial resolution of 1 km x 1 km we present the used approach : Firstly, the extraction of rain support (rain/no rain area) allowing the retrieval of the rain support structure function (variogram) and fractal properties. This leads us to use either the rain support modelisation proposed by ScleissXXX [ref] or directly real rain support extracted from radar rain maps. Then, the generation (over rain areas) of rain rates is made thanks to a 2D multifractal Fractionnally Integrated Flux (FIF) model [ref]. This second stage is followed by a calibration/forcing step (forcing average rain rate per events) added in order to provide rain rate coherent with observed rain-rate distribution. The forcing process is based on a relation identified from the average rain rate of observed events and their surfaces. The presentation will first explain the different steps presented above, then some results

  19. Cosmogenic radioisotopes on LDEF surfaces

    NASA Technical Reports Server (NTRS)

    Gregory, J. C.; Albrecht, A.; Herzog, G.; Klein, J.; Middleton, R.

    1992-01-01

    The radioisotope Be-7 was discovered in early 1990 on the front surface, and the front surface only, of the LDEF. A working hypothesis is that the isotope, which is known to be mainly produced in the stratosphere by spallation of nitrogen and oxygen nuclei with cosmic ray protons or secondary neutrons, diffuses upward and is absorbed onto metal surfaces of spacecraft. The upward transport must be rapid, that is, its characteristic time scale is similar to, or shorter than, the 53 day half-life of the isotope. It is probably by analogy with meteoritic metal atmospheric chemistry, that the form of the Be at a few 100 km altitude is as the positive ion Be(+) which is efficiently incorporated into the ionic lattice of oxides, such as Al2O3, Cr2O3, Fe2O3, etc., naturally occurring on surfaces of Al and stainless steel. Other radioisotopes of Be, Cl, and C are also produced in the atmosphere, and a search was begun to discover these. Of interest are Be-10 and C-14 for which the production cross sections are well known. The method of analysis is accelerator mass spectrometry. Samples from LDEF clamp plates are being chemically extracted, purified, and prepared for an accelerator run.

  20. Radioisotope penogram in diagnosis of vasculogenic impotence

    SciTech Connect

    Fanous, H.N.; Jevtich, M.J.; Chen, D.C.; Edson, M.

    1982-11-01

    A radioisotope technique to estimate penile blood flow is described. The radioisotope penogram is noninvasive and gives a dynamic evaluation of the arterial supply, venous drainage, and blood flow in the corporeal bodies. The penogram is a valuable adjunct in evaluation of patients with vasculogenic impotence.

  1. Status of the NASA Stirling Radioisotope Project

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    2007-01-01

    Free-piston Stirling power conversion has been considered a candidate for radioisotope power systems for space for more than a decade. Prior to the free-piston Stirling architecture, systems were designed with kinematic Stirling engines that used linkages and rotary alternators to convert heat to electricity. These systems were able to achieve long life by lightly loading the linkages; however, the live was nonetheless limited. When the free-piston configuration was initially proposed, it was thought to be attractive due to the relatively high conversion efficiency, acceptable mass, and the potential for long life and high reliability based on wear-free operation. These features have consistently been recognized by teams that have studied technology options for radioisotope space power systems. Since free-piston Stirling power conversion was first considered for space power applications, there have been major advances in three general areas of development: hardware that has demonstrated long-life and reliability, the success achieved by Stirling cryocoolers in space, and the overall developmental maturity of the technology for both space and terrestrial applications. Based on these advances, free-piston Stirling convertors are currently being developed for space power, and for a number of terrestrial applications. They commonly operate with the power, efficiency, life, and reliability as intended, and much of the development now centers on system integration. This paper will summarize the accomplishments of free-piston Stirling power conversion technology over the past decade, review the status of development with regard to space power, and discuss the challenges that remain.

  2. A rule-based software test data generator

    NASA Technical Reports Server (NTRS)

    Deason, William H.; Brown, David B.; Chang, Kai-Hsiung; Cross, James H., II

    1991-01-01

    Rule-based software test data generation is proposed as an alternative to either path/predicate analysis or random data generation. A prototype rule-based test data generator for Ada programs is constructed and compared to a random test data generator. Four Ada procedures are used in the comparison. Approximately 2000 rule-based test cases and 100,000 randomly generated test cases are automatically generated and executed. The success of the two methods is compared using standard coverage metrics. Simple statistical tests showing that even the primitive rule-based test data generation prototype is significantly better than random data generation are performed. This result demonstrates that rule-based test data generation is feasible and shows great promise in assisting test engineers, especially when the rule base is developed further.

  3. Radioisotopes for radioimmunodetection (RAID) and radioimmunotherapy (RAIT)---current and new perspectives

    SciTech Connect

    Knapp, F.F. Jr.

    1991-01-01

    In this paper the availability and properties of radioisotopes for both radioimmunodiagnosis (RAID) and radioimmunotherapy (RAIT) are discussed. Examples are provided for radioisotopes available via direct production in nuclear reactors and accelerators or as daughters obtained from radionuclide generator systems whose parents are either reactor or accelerator produced. Important factors which must be considered for the use of a particular radioisotope include availability, the physical half-life and decay properties, and chemical versatility for protein attachment. Although both direct'' and indirect'' methods are available for attachment of radioisotopes to antibodies, this broad field of research is not reviewed in detail. Practical issues related to the availability and use of a variety of radionuclides are described. 47 refs., 5 tabs.

  4. BEST medical radioisotope production cyclotrons

    NASA Astrophysics Data System (ADS)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Gelbart, W. Z.; Johnson, Richard R.

    2013-04-01

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 μA to 1000 μA, depending on the cyclotron energy and application [1].

  5. Radioisotope scanning in osseous sarcoidosis

    SciTech Connect

    Rohatgi, P.K.

    1980-01-01

    Technetium-99m (/sup 99m/Tc)-labeled pyrophosphate or diphosphonate compounds and gallium-67 citrate (/sup 67/Ga) are two radionuclide scanning agents that are in widespread use in clinical practice. Technetium-99m pyrophosphate is used extensively for bone scanning to detect metastatic bone disease, benign bone tumors, osteomyelitis, benign hypertrophic osteoarthropathy, and Paget's disease. Only two reports describe abnormal /sup 99m/Tc/ pyrophosphate bone scans in four patients with osseous sarcoidosis. Gallium-67 scans are used primarily to localize neoplastic or inflammatory lesions anywhere in the body. In recent years /sup 67/Ga scans have also been used to detect the presence of both pulmonary and extrapulmonary sarcoidosis, but there are no reports describing abnormal uptake of gallium in patients with osseous sarcoidosis. This report describes experience with radioisotope scanning in two patients with osseous sarcoidosis.

  6. BEST medical radioisotope production cyclotrons

    SciTech Connect

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Johnson, Richard R.; Gelbart, W. Z.

    2013-04-19

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 {mu}A to 1000 {mu}A, depending on the cyclotron energy and application.

  7. Safety status of space radioisotope and reactor power sources

    NASA Technical Reports Server (NTRS)

    Bennett, Gary L.

    1990-01-01

    The current overall safety criterion for both radioisotope and reactor power sources is containment or immobilization in the case of a reentry accident. In addition, reactors are designed to remain subcritical under conditions of land impact or water immersion. A very extensive safety test and analysis program was completed on the radioisotope thermoelectric generators (RTGs) in use on the Galileo spacecraft and planned for use on the Ulysses spacecraft. The results of this work show that the RTGs will pose little or no risk for any credible accident. The SP-100 space nuclear reactor program has begun addressing its safety criteria, and the design is planned to be such as to ensure meeting the various safety criteria. Preliminary mission risk analyses on SP-100 show the expected value population dose from postulated accidents on the reference mission to be very small. It is concluded that the current US nuclear power sources are the safest flown.

  8. Radioisotope Electric Propulsion for Fast Outer Planetary Orbiters

    NASA Technical Reports Server (NTRS)

    Oleson, Steven; Benson, Scott; Gefert, Leon; Patterson, Michael; Schreiber, Jeffrey

    2002-01-01

    Recent interest in outer planetary targets by the Office of Space Science has spurred the search for technology options to enable relatively quick missions to outer planetary targets. Several options are being explored including solar electric propelled stages combined with aerocapture at the target and nuclear electric propulsion. Another option uses radioisotope powered electric thrusters to reach the outer planets. Past work looked at using this technology to provide faster flybys. A better use for this technology is for outer planet orbiters. Combined with medium class launch vehicles and a new direct trajectory these small, sub-kilowatt ion thrusters and Stirling radioisotope generators were found to allow missions as fast as 5 to 12 years for objects from Saturn to Pluto, respectively. Key to the development is light spacecraft and science payload technologies.

  9. US Department of Energy radioisotope customers with summary of radioisotope shipments, FY 1988

    SciTech Connect

    Van Houten, N.C.

    1989-06-01

    Pacific Northwest Laboratory (PNL) prepared this edition of the radioisotope customer list at the request of the Office of Health and Environmental Research (ER-73), Office of Energy Research, US Department of Energy (DOE). This is the 25th report in a series dating from 1964. This report covers DOE radioisotope sales and distribution activities by its facilities to domestic, foreign and other DOE facilities for FY 1988. The report is divided into five sections: radioisotope suppliers, facility contacts, and radioisotopes or services supplied; a list of customers, suppliers, and radioisotopes purchased; a list of radioisotopes purchased cross-referenced to customer numbers; geographic locations of radioisotope customers; and radioisotope sales and transfers -- FY 1988. Radioisotopes not previously reported in this series of reports were argon-37, arsenic-72, arsenic-73, bismuth-207, gadolinium-151, rhenium-188, rhodium-101, selenium-72, xenon-123 and zirconium-88. The total value of DOE radioisotope sales for FY 1988 was $11.1 million, an increase of 3% from FY 1987.

  10. Virus-based piezoelectric energy generator

    SciTech Connect

    2012-01-01

    Lawrence Berkeley National Laboratory scientists have developed a way to generate power using harmless viruses that convert mechanical energy into electricity. The milestone could lead to tiny devices that harvest electrical energy from the vibrations of everyday tasks. The first part of the video shows how Berkeley Lab scientists harness the piezoelectric properties of the virus to convert the force of a finger tap into electricity. The second part reveals the "viral-electric" generators in action, first by pressing only one of the generators, then by pressing two at the same time, which produces more current.