Browse Topic: Nuclear fuel

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Assessment of Non-Traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear ActivitiesTBMG-273848/1/2017
The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources.
Assessment of Non-Traditional Isotopic Ratios by Mass Spectrometry for Analysis of Nuclear Activities17AERP08_106/1/2017
Technique can be used to distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Defense Threat Reduction Agency, Fort Belvoir, Virginia The objective of this work is to identify isotopic ratios suitable for analysis via mass spectrometry that distinguish between commercial nuclear reactor fuel cycles, fuel cycles for weapons grade plutonium, and products from nuclear weapons explosions. Methods will also be determined to distinguish the above from medical and industrial radionuclide sources. There are many sources for radionuclides in our environment. These include natural sources, the commercial nuclear industry, nuclear weapons, the medical industry, and other sources. Often times, the source of the radionuclide may be determined through just identification of the radionuclide. If radionuclides are produced through different sources, the identification of the source is complex. In order to ascertain a specific source for attribution, radionuclide ratios are often employed.
Fluid Harmonic AbsorberTBMG-251818/1/2016
NASA Marshall Space Flight Center’s Fluid Structure Coupling (FSC) technology is a highly efficient and passive method to control the way fluids and structures communicate and dictate the behavior of a system. This technology has the demonstrated potential to mitigate a multitude of different types of vibration issues, and can be applied anywhere internal or external fluids interact with physical structures. For example, in a multistory building, water from a rooftop tank or swimming pool could be used to mitigate seismic or wind-induced vibration by simply adding an FSC device that controls the way the building engages the water.
A Theoretical Approach of UNIT (Unified Nuclear Integral Technology) Propulsion and its Potential for Future Applications in Space Exploration2015-01-90049/1/2015
Space exploration is the present inevitable challenge for researchers. Various theoretical propulsion concepts have been evolved over the past years for space missions. Their potential remains as a key factor for the spacecraft to travel deeper into space in a shorter mission duration. The propulsion concept UNIT is an integrated nuclear propulsion technique that provides high entry, descent and landing (EDL) performance in such short duration to conquer other galaxies. This paper describes the theoretical approach of the UNIT propulsion system in detail. UNIT produces the highest energy possible by consuming nuclear fuel and possess the highest potential that opens new opportunities for space exploration. The principle is that the neutrons from the fusion are deliberately allowed to induce fission. It uses National Ignition Facility's laser beam for inertial confinement fusion followed by utilizing the power from tubular solid fuel cell. Thus, the net thrust is produced from the expansion of the combined plasma of the nuclear fusion and nuclear fission reactions through the nozzle.
Dran, Sarath Ramachan
Radioisotope System Keeps Mars Rover MovingTBMG-166146/1/2013
The instruments aboard NASA’s Mars Science Laboratory “Curiosity” rover receive their power from a radioisotope system assembled and tested at Idaho National Laboratory. The Multi- Mission Radioisotope Thermoelectric Generator is a “space battery” that can reliably power a deep space mission for many years.
Grooved Fuel Rings for Nuclear Thermal Rocket EnginesTBMG-35452/1/2009
An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants.
Improved Operation of CO 2 Separator for Preventing Increases in CO 2 Concentration of Air in the Habitation Room during Closed Habitation Experiments2007-01-30977/9/2007
The main objective of the activities of the Closed Ecology Experiment Facilities (CEEF) is to construct a mathematical model to predict the transfer of radiocarbon (14C) released from a nuclear fuel reprocessing plant in the village of Rokkasho into the local ecosystem. For this purpose, an artificial ecosystem, including crops, domestic animals, and human inhabitants, needs to be maintained in the CEEF for several months. As a preparatory study, two-week habitation experiments using the CEEF were planned in 2006. In the first habitation experiment, a CO2 separator was continuously operated with a cycle of 60-minute adsorption and 60-minute desorption periods in order to remove excess CO2 from the habitation room, and the maximum CO2 concentration of air in this room slightly exceeded 5000 ppm, which was identical to the maximum 8-hour exposure permitted for industrial settings. In the second habitation experiment, therefore, the duration of both the adsorption and desorption periods for the operation of the CO2 separator was shortened to 54 minutes in order to increase the cumulative number of adsorption periods per day. The approx. 10% increase in the cumulative number of adsorption periods per day resulted in a decrease of approx. 10% in the maximum CO2 concentration of air in the habitation room during the second habitation experiment. This result demonstrated how the improved operation of the CO2 separator contributed to maintaining the CO2 concentration of air in the habitation room below the maximum 8-hour exposure permitted for industrial settings.
Tani, Takashi, Tsuga, Shouichi, Tako, Yasuhiro
Dielectric Heaters for Testing Spacecraft Nuclear ReactorsTBMG-4052/1/2006
Like the electrical-resistance heaters used heretofore for such testing, the dielectric heaters would be inserted in the reactors in place of nuclear fuel rods. A typical heater according to the proposal would consist of a rod of lossy dielectric material sized and shaped like a fuel rod and containing an electrically conductive rod along its center line. Exploiting the dielectric loss mechanism that is usually considered a nuisance in other applications, an RF signal, typically at a frequency =50 MHz and an amplitude between 2 and 5 kV, would be applied to the central conductor to heat the dielectric material. The main advantage of the proposal is that the wiring needed for the RF dielectric heating would be simpler and easier to fabricate than is the wiring needed for resistance heating. In some applications, it might be possible to eliminate all heater wiring and, instead, beam the RF heating power into the dielectric rods from external antennas.
Estimation of Water Circulation Based on Experimental Results from Sequential Crop Cultivation, Closed Goat Breeding and Simulated Habitation Using CEEF2004-01-23497/19/2004
Closed habitation experiments are to be carried out using Closed Ecology Experiment Facilities (CEEF) from FY2005 to FY2009. The last target of duration of closed habitation is four months. Preliminary study and testing have been conducted in order to carry out the closed habitation experiments. The CEEF has three closed plantation chambers (PC-A, B and C) with artificial lighting solely having each cultivation area of 30 m2 and a closed plantation chamber (PC-F) with both natural lighting and supplemental artificial lighting having a 60-m2 cultivation area. A ‘stable’ period of sequential crop cultivation was maintained for four weeks in a trial experiment conducted in FY2003 using the Plantation Module (PM), in which rice, soybean and crops including rice sapling, soybean sapling, soybean, peanuts and safflower were cultivated in PC-A, PC-B, PC-C and PC-F, respectively. Amount of total clean water input to PM was 741 L day−1 on the average for the period. That includes 645 L day−1 of replenishing water supplied to plant cultivation beds and 96 L day−1 of humidifying water. Amounts of condensate and water in harvested biomass from the PM were 681 and 8.4 L day−1, respectively. In addition to them, 1311 L day−1 of nutrient solution in the plant cultivation beds was exchanged. The waste nutrient solution was processed through the Reverse Osmosis membrane (RO) system.1245 L day−1 of water having solute concentration of less than 5% of that of the waste nutrient solution was recovered. Both condensate sterilized through Ultra Violet ray exposure system and water processed through the RO were used for making of new nutrient solution. Amounts of water in food, drinking water and other water consumption including washing, shower and sanitary for two persons during a simulated closed habitation trial lasting five days conducted in FY2003 were 2.9, 1.0 and 112 L day−1, respectively. Amount of water in rice straw as feeding, drinking water and cage washing water for two Shiba-goats each having 25-kg body weight during closed breeding experiment conducted in FY2003 were estimated as 0.1, 5.7 and 0.4 L day−1, respectively. Using above data and estimation result, water flow in the CEEF material circulation system was estimated.
Tako, Yasuhiro, Tsuga, Shou-ichi, Arai, Ryuji, Tani, Takashi, Honda, Go, Nitta, Keiji
Matching of Gas Metabolism among Crop Community, Human and Animal in the CEEF2003-01-24527/7/2003
Rating of daily amounts of CO2 and O2 exchange of crops, animals and humans to be involved in the long-term habitation experiments using the Closed Ecology Experiment Facilities (CEEF) were carried out. Daily amounts of the CO2-absorption and O2-generation of crops including rice, soybeans and other 27 vegetables were estimated from data obtained from a sequential crop cultivation experiment conducted from August to December of FY2001. Daily amounts of O2-consumption and CO2-expiration of two female Shiba goats to be involved were estimated based on gas exchange determination conducted in FY2002. Daily amounts of CO2-expiration and O2-consumption of two persons to be involved were estimated based on correlation between respiration rate and heart rate, heart rate data during the simulated habitation in the CEEF and a tentative work schedule. In order to discuss about whole material circulation, it is necessary to accumulate more data on rates of O2-consumption and CO2-generation of the waste processors and those on performance of the Sabatier O2 recovery system, in addition to those on biological systems.
Tako, Yasuhiro, Honda, Go, Komatsubara, Osam, Shinohara, Masanori, Arai, Ryuji, Nitta, Keiji
Automated Assembly of Large Products9722326/3/1997
The continuous need for agility coupled with increasing labour costs and improvements in reliability and capability of automation has meant a renewed interest in the application of robots to many manufacturing activities. Research at the University of the West of England, Bristol has focused on the design of an integrated, modular system for the assembly of large products. The work under the ALASCA project has resulted in a number of technologies that will significantly affect assembly automation. The paper will discusses the latest results from this work and presents the experimental conclusions thus far.
Dailami, Farid, Redford, Alan
Partial Radiation Insulated Diode (PRID) for Space Nuclear Power Systems9291338/3/1992
The in-core thermionic nuclear reactor is a leading candidate for low power space systems requirements. The thermionic converters are static devices which convert heat directly to electricity in the form of high current, low voltage output power. The nuclear fuel cladding is used as the emitting electrode and is surrounded with close spacing by the collector electrode. The stability and lifetime of the system depend on the maintenance of the interelectrode gap established by the resulting coaxial geometry. Emitter distortion, therefore, can be a life-limiting factor. This is exacerbated by high emitter temperature and high fuel power density present in typical applications. In the particular case of low nuclear power level systems, the added complexity of a fast driver core section is necessary to ensure sufficient excess reactivity for power control. A modification of the present TFE provides design flexibility which allows trade-offs to be made among emitter distortion, emitter temperature and lifetime while increasing fuel-volume ratio and eliminating the driver in the low power level core design. The converter concept PRID (Partial Radiation Insulated Diode), by eliminating a portion of the interelectrode thermal radiation, allows for increased pin size and reduced fuel power density, and can lead to a more efficient and desirable longer TFE cell.
Hatch, G. L., McVey, J. B., Fitzpatrick, G. O., Allen, D. T.
10 KWe Dual-Mode Space Nuclear Power System for Military and Scientific Applications9290728/3/1992
A 10 KWe dual-mode space power system concept has been identified which is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. The direct thrust capability can provide tens of pounds of thrust at a specific impulse of around 730 seconds for maneuvers that must be performed more rapidly. The direct thrust allows the nuclear power system to move a payload from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) in less than one month using approximately half the propellant of a cryogenic chemical stage. The low mass of the power system (approximately 1000 Kg) allows it to be used with payloads launched from Atlas II and potentially Delta launch vehicles, reducing launch costs. This paper will focus on the nuclear power system design, including: the reactor with its UO2 fuel in tungsten clad, 36 thermionic heat pipe modules (THPMs) which produce electricity within the reactor and remove waste heat, radiation shielding, waste heat radiators, and reactivity control systems. The use of non-vented fuel elements for short lifetime missions (under five years) will be described. Non-vented fuel elements reduce the complexity of fuel development and qualification, allowing the system to reach flight status sooner. Methods for producing direct thrust using hydrogen propellant and the mission advantages provided by this direct thrust capability will be briefly discussed.
Malloy, John, Westerman, Kurt, Rochow, Richard, Scoles, Stephen
Nuclear Fuels for Very High Temperature Applications9290778/3/1992
The success of the development of nuclear thermal propulsion devices and thermionic space nuclear power generation systems depends on the successful utilization of nuclear fuel materials at temperatures in the range 2000 to 3500 K. Problems associated with the utilization of uranium bearing fuel materials at these very high temperatures while maintaining them in the solid state for the required operating times are addressed. The critical issues addressed include evaporation, melting, reactor neutron spectrum, high temperature chemical stability, fabrication, fission induced swelling, fission product release, high temperature creep, thermal shock resistance, and fuel density, both mass and fissile atom. Candidate fuel materials for this temperature range are based on UO2 or uranium carbides. Evaporation suppression, such as a sealed cladding, is required for either fuel base. Nuclear performance data needed for design are sparse for all candidate fuel forms in this temperature range, especially at the higher temperatures.
Lundberg, L. B., Hobbins, R. R.
SPACE-R: A Fully Testable Nuclear Space Power System with Advanced Core-Length Single Cell Thermionic Fuel Elements9292368/3/1992
The Space Power Advanced Core-Length Element Reactor (SPACE-R) System is a moderated core fueled by uranium oxide. The baseline power level is 40 kWe with a system life of 10 years. The system is launched without radioactivity and is designed to meet all U.S. and international public safety and environmental protection objectives with minimum loading of fissionable 235U and minimum proliferation potential. The key feature of the SPACER system is the core-length, single-cell thermionic fuel element (TFE). The open end of the emitter cavity permits an electrical heater to be inserted for full power operational testing of each TFE and the entire reactor assembly before the UO2 fuel is loaded. The current design is based upon technologies, materials, components, and temperatures that have been space flight proven within the U.S. SNAP reactor program, and the Soviet Topaz reactor programs.
Rhee, Hyop S., Wetch, Joseph R., Gunther, Norman G., Zheng, Cinian M., Britt, Edward J., Schmidt, Glen L.
Sealability of Spring-Energized Elastic Metal Gaskets8700042/1/1987
This paper describes the experimental results of a type of spring -energized elastic metal gaskets consisting of a helical core spring wrapped with a soft metal envelope for the application to cask seals. Tests were carried out to evaluate the seal life by means of a relaxation curve and to make clear the sealing reliability under thermal stresses by using a helium leak detector with a sensitivity of 1×10−10 - 6×10−11 torr·1/sec, resulted in satisfactory to the applications intended for the gaskets.
Nishida, Takahito
The Clinton Power Station Project7705052/1/1977
The Clinton Power Station Project is described from the planning to the construction stage, which is now in progress. The earthmoving required, particularly by the powerplant's most unique feature, a 5000 acre cooling lake, is detailed. A rationale for selecting nuclear power for this station is also presented.
Womeldorff, P. J.
Hydrogen Automotive Fuel: Production and Delivery7605682/1/1976
Today's principal and cheapest source of hydrogen in the United States, steam-reformed natural gas, does not have attractive prospects in the far-term future. Alternative procedures or processes therefore are in various phases of research and development. Hydrogen can be produced by the electrolysis of water, and production of hydrogen from coal and water is under study. Thermochemical, photochemical, and biochemical procedures are being researched as long-term routes to hydrogen. Feasibility studies indicate the possibility of long-distance transmission of hydrogen gas via pipeline. Local distribution of hydrogen fuel presents a major problem that requires investigation and development. Technically and economically, other synthetic fuels, such as liquid hydrocarbons from coal or oil shale, are favored alternative automotive fuels for the mid-term future.
Pangborn, J. B., Donakowski, T. D.
Total Energy Situation in the United States7305142/1/1973
In the past 20 years in the United States, the demand for energy has doubled, and it is expected to increase by 3.6% annually until the end of the twentieth century. This paper discusses the implications of the increased demand, and the resources needed to meet it. Nuclear power is seen as a partial answer, as is low-sulfur coal. Some untapped oil reserves are available in the United States, but oil will undoubtedly have to be imported to meet the demand. A concerted effort to conserve energy is needed to help hold imports to acceptable levels.
Oliver, David R.
Minimum-volume Gas-cooled Nuclear Heat Exchangers6103261/1/1961
Fulton, C. D., Thomson, W. B.
NUCLEAR ROCKETS FOR LIFTING MANNED STATIONS INTO SPACE6002891/1/1960
CROUCH, HOLMES F.
Automotive Nuclear-Heat Engines and Associated High-Temperature Materials5700361/1/1957
APPLICATION of nuclear energy for civilian automotive uses has possibilities, these authors say. Nuclear power for automotive applications, they feel, is technically feasible now where size and weight are not prime considerations; where size and weight are major parameters, discoveries of new materials for construction of nuclear-power reactors must be made. New materials are needed for reactor fuels, heat extractants, neutron reflectors, reactor construction materials, controls, and radiation shields which must have unique nuclear properties in addition to conventional engineering properties. This paper presents nuclear automotive propulsion devices in terms of technologies now available. The necessary radiation-shielding mass and weight requirements are presented for an ideal point-source nuclear-heat-power engine.
Schwartz, F. L, Ohlgren, H. A.
NUCLEAR POWER IN THE AIR OF TOMORROW5602721/1/1956
OHLINGER, LEE A.
Nuclear Power and the Machinery Builder5600531/1/1956
IN LIGHT of the world's continually increasing demand for electric power and the attendant decrease in economically recoverable fossil fuels, the need for nuclear powerplants becomes all the more pressing. The author briefly covers in a general way several developments in design of different reactor types. Some problems inherent in generating power from fissionable isotopes are mentioned, together with the solutions which will enable the realization of electric current generation from the “burning” of nuclear fuels. Some startling theoretical schemes are mentioned which bid fair to making the generation and transmission of electric current in the future so different from our present methods as to mark the coming of age of yesterday's and today's science fiction.
Allen, R. C.
THE POTENTIAL CONTRIBUTION OF THE AUTOMOTIVE INDUSTRY TO THE FIELD OF ATOMIC ENERGY5500111/1/1955
TAMMARO, A.
THE FUTURE OF ATOMIC ENERGY IN INDUSTRY5300261/1/1953
CISLER, WALKER L.
ATOMIC POWER And Aircraft Propulsion4901731/1/1949
AFTER outlining the fundamental physical background for the release of atomic energy, the author shows that the high concentration of energy and the high cost and relative scarcity of atomic fuels mark them for use where there is a high premium on performance, rather than on direct cost per unit of power. This makes atomic energy attractive for aircraft propulsion, where it could combine high performance with large payload and long range. Chief obstacles in design of an atomic aircraft engine are development of light-weight shielding against deadly radiations; adequate cans to retain radioactive fission products; a pile capable of operating at high temperature and high thermal stresses; and a safe, flexible control mechanism.
Kalitinsky, Andrew
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