152 research outputs found
The moon: An abundant source of clean and safe fusion fuel for the 21st century
It is shown how helium-3 can be obtained from the moon and how its use in fusion reactors can benefit the inhabitants of this planet. The physics and technology issues associated with the use of He-3 is addressed. A description is given of He-3 distribution on the moon and of methods which could be used to retrieve it
Analysis of the financial factors governing the profitability of lunar helium-3
Financial factors influencing the profitability of the mining and utilization of lunar helium-3 are examined. The analysis addressed the following questions: (1) which financial factors have the greatest leverage on the profitability of He-3; (2) over what range can these factors be varied to keep the He-3 option profitable; and (3) what ultimate effect could this energy source have on the price of electricity for U.S. consumers. Two complementary methods of analysis were used in the assessment: rate of return on incremental investment required and reduction revenue requirements (total cost to customers) achieved. Some of the factors addressed include energy demand, power generation costs with and without fusion, profitability for D-He(3) fusion, annual capital and operating costs, launch mass and costs, He-3 price, and government funding. Specific conclusions are made with respect to each of the companies considered: utilities, lunar mining company, and integrated energy company
Potential of derived lunar volatiles for life support
The lunar regolith contains small quantities of solar wind implanted volatile compounds that have vital, basic uses for maintaining life support systems of lunar or space settlements. Recent proposals to utilize the helium-3 isotope (He-3) derived from the lunar regolith as a fuel for fusion reactors would result in the availability of large quantities of other lunar volatile compounds. The quantities obtained would provide the annual life support replacement requirements of 1150 to 23,000 inhabitants per ton of He-3 recovered, depending on the volatile compound. Utilization of the lunar volatile compounds for life support depends on the costs, in terms of materials and energy, associated with their extraction from the lunar regolith as compared to the delivery costs of these compounds from Earth resources. Considering today's conservative estimated transportation costs (5 dollars per ton), the life support replacement requirements could be more economically supplied by recovering the lunar volatile compounds than transporting these materials from Earth resources, even before He-3 will be utilized as a fusion fuel. In addition, availability of lunar volatile compounds could have a significant cost impact on maintaining the life support systems of the space station and a Mars base
Fusion and Fast Breeder Reactors
In a two year study, a team of researchers has evolved a comparison of fast fission breeders and D-T fusion reactors, as both nuclear reactors allow, at least in principle, for an essentially unlimited supply of large amounts of energy. In this report, resources for the two reactor types are briefly reviewed, and their present status is discussed in terms of scientific, engineering, and commercial feasibility. Reference reactor systems are the German/Belgian/Dutch fast breeder prototype SNR 300, a liquid-metal fast breeder reactor, and the deuterium-tritium TOKAMAK fusion reactor concept. Radioactive inventories of reactor economies are discussed in length, with emphasis on the biological hazard potential index for comparing relative hazards on pathways (inhalation, ingestion) and injuries to the human body. The safety problem involved in normal operating losses and exposure centers around releases of tritium in fusion, and around alpha-emitters, iodine-129, and krypton in fission. Design basis accidents as well as acts of war, sabotage, and hypothetical events are dealt with under non-routine releases. Safeguards are analyzed in the non-proliferation context. Materials--a problem more severe for fusion than for fission--and the impact of radiation damage are an important chapter. Reactor strategies for commercialization are evaluated in terms of timing of related programs and their funding. Great care has been taken to appropriately introduce the problem of nuclear energy and to put the conclusions in the proper perspective
Fusion energy from the Moon for the twenty-first century
It is shown in this paper that the D-He-3 fusion fuel cycle is not only credible from a physics standpoint, but that its breakeven and ignition characteristics could be developed on roughly the same time schedule as the DT cycle. It was also shown that the extremely low fraction of power in neutrons, the lack of significant radioactivity in the reactants, and the potential for very high conversion efficiencies, can result in definite advantages for the D-He-3 cycle with respect to DT fusion and fission reactors in the twenty-first century. More specifically, the D-He-3 cycle can accomplish the following: (1) eliminate the need for deep geologic waste burial facilities and the wastes can qualify for Class A, near-surface land burial; (2) allow 'inherently safe' reactors to be built that, under the worst conceivable accident, cannot cause a civilian fatality or result in a significant (greater than 100 mrem) exposure to a member of the public; (3) reduce the radiation damage levels to a point where no scheduled replacement of reactor structural components is required, i.e., full reactor lifetimes (approximately 30 FPY) can be credibly claimed; (4) increase the reliability and availability of fusion reactors compared to DT systems because of the greatly reduced radioactivity, the low neutron damage, and the elimination of T breeding; and (5) greatly reduce the capital costs of fusion power plants (compared to DT systems) by as much as 50 percent and present the potential for a significant reduction on the COE. The concepts presented in this paper tie together two of the most ambitious high-technology endeavors of the twentieth century: the development of controlled thermonuclear fusion for civilian power applications and the utilization of outer space for the benefit of mankind on Earth
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Fusion reactor design studies
This progress report will give a detailed breakdown of the work accomplished for ARIES-III during the contract period, November 1, 1990 to October 31, 1991. The areas of effort discussed are: Neutronics; First-Wall; Shield; Safety; Systems; Startup and Shutdown; Energy Conversion; Ripple Loss; and Fuel Resources
Advanced power sources for space missions
Approaches to satisfying the power requirements of space-based Strategic Defense Initiative (SDI) missions are studied. The power requirements for non-SDI military space missions and for civil space missions of the National Aeronautics and Space Administration (NASA) are also considered. The more demanding SDI power requirements appear to encompass many, if not all, of the power requirements for those missions. Study results indicate that practical fulfillment of SDI requirements will necessitate substantial advances in the state of the art of power technology. SDI goals include the capability to operate space-based beam weapons, sometimes referred to as directed-energy weapons. Such weapons pose unprecedented power requirements, both during preparation for battle and during battle conditions. The power regimes for these two sets of applications are referred to as alert mode and burst mode, respectively. Alert-mode power requirements are presently stated to range from about 100 kW to a few megawatts for cumulative durations of about a year or more. Burst-mode power requirements are roughly estimated to range from tens to hundreds of megawatts for durations of a few hundred to a few thousand seconds. There are two likely energy sources, chemical and nuclear, for powering SDI directed-energy weapons during the alert and burst modes. The choice between chemical and nuclear space power systems depends in large part on the total duration during which power must be provided. Complete study findings, conclusions, and eight recommendations are reported
Some experimental considerations regarding ion beam simulation of neutron irradiation for mechanical property measurements
A preliminary assessment of the requirements for mechanical property data related to CTR materials is given. The status of ion simulation for mechanical property measurements is described. A damage analysis and calculations for light ions are presented along with sample size, heating and cooling, and surface considerations. (MOW
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