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

Dran, Sarath Ramachan

RADIOISOTOPE POWER SYSTEMS

AIR1213 (Historical)

07/06/2010

AE-7C Systems

Grooved Fuel Rings for Nuclear Thermal Rocket Engines

TBMG-354502/01/2009

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 Experiments

2007-01-309707/09/2007

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

Tani, Takashi, Tsuga, Shouichi, Tako, Yasuhiro

Dielectric Heaters for Testing Spacecraft Nuclear Reactors

TBMG-405

02/01/2006

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.

Telling the future

AERODEC03_0112/01/2003

Technology and the environment, BWBs and UAVs, and nuclear power may be the forces for the future of aerospace engineering. If one thinks of the inexorable climb of aviation and aerospace technology during the past 100 years as being spectacular, then the future is likely to bring the sort of advances that today may seem unthinkable. There are two levels of likely development. The steady evolution of what is available now in terms of materials, powerplants, electronic systems, and overall concepts is one level, which calls for expertise and application but is basically conservative, cautious, and sometimes unimaginative.

Birch, Stuart

Hydrogen and the automobile

AUTOSEP02_0509/01/2002

Though the fuel could emerge as the primary energy source for nonpolluting passenger vehicles, massive infrastructure development is needed in the U.S. to support the hydrogen economy of the future. The hydrogen economy is being touted as the answer to the transportation sector's dependence on polluting and finite fuels. An almost infinitely abundant energy source with well-understood properties, hydrogen could emerge as the primary fuel source for nonpolluting fuel-cell vehicles. The gas offers benefits from an emissions standpoint when used in conventional combustion engines as well. Hydrogen's potential is vast, but it will not be realized until fundamental infrastructure issues are addressed. The hydrogen economy will not happen until reliable, cost-effective methods are identified in three basic yet essential areas: production, distribution/delivery, and storage. Some infrastructure necessary to support the dream of a hydrogen future does exist, but it is far from being sufficient

Chinworth, Michael

Partial Radiation Insulated Diode (PRID) for Space Nuclear Power Systems

92913308/03/1992

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

Fitzpatrick, G. O., Allen, D. T., Hatch, G. L., McVey, J. B.

Preliminary Testing of a Planar Converter with Uranium Oxide Pellets in the Emitter

92913008/03/1992

Nuclear reactor thermionic space power systems incorporating thermionic fuel element generally use refractory metal emitters, which contain the nuclear fuel. The purpose of the current work is to determine the effect, If any, of the diffusion of uranium oxide fuel through chemically vapor deposited (CVD) tungsten on converter performance. The test vehicle Is a modified, planar variable-spaced research converter. The emitter, with an effective area of 1 cm2, contains four depleted uranium oxide fuel pellets, 4 mm in diameter. The converter equipped with a cesium graphite reservoir, was charged with cesium during the preliminary testing. This paper describes the preliminary testing of the converter to assess the converter performance before any significant diffusion takes place. The testing was carried out with the usual protocol. The emitter temperature was 1800 K and the collector temperature was varied from 1000 K to 1070 K. The range of interelectrode spacing was from .25 to .5 mm

Miskolczy, Gabor, Lieb, David P., Hatch, G. Laurie

Nuclear Fuels for Very High Temperature Applications

92907708/03/1992

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

Lundberg, L. B., Hobbins, R. R.

Equipment Needs to Meet the Challenge of Surface Mining of Coal and Uranium in the Decade Ahead

73044802/01/1973

This paper focuses on the 1975-1985 period in attempting to demonstrate the equipment requirements in the coal and uranium industries for that period. It has been necessary to make a number of far-reaching estimates with regard to future demand for the two commodities, as well as for strip ratios and equipment performance. However, the projections indicate the magnitude, both in terms of quantity and growth potential, of the industry needs and, as such, should provide equipment manufacturers with useful information for the future. In the coal industry, it appears that both stripping and mining equipment needs will grow at a rate of 10-12%/year in the future. This equipment will not be radically different from that used today even though some increases in size will probably occur in some equipment lines. The emphasis will be upon improvement in present generation machinery. The same may also be true in the uranium industry. Growth rates on the order of perhaps 50%/year will be

Ritchie, M. I.

Automotive Nuclear-Heat Engines and Associated High-Temperature Materials

570036

01/01/1957

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 and the Machinery Builder

56005301/01/1956

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.

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