Subcritical cascade liquid-salt reactor as an element of the fuel cycle

Abstract

Large-scale development of nuclear power is pointless if there is no long-term future for it and if it cannot meet the requirements that are predicted for the future. There is still no serious competitor for nuclear power in the long-term future, besides thermonuclear power, which must still prove to be economical and efficient, not only in the variant of purely thermonuclear power but also in a hybrid variant with subcritical blankets. This has not yet been demonstrated, and the possibility of nuclear power, whose realizability and cost-effectiveness have already been proven, must be analyzed seriously.In order to be realized on large scales in the long-term future nuclear power must meet the following requirements: it must be cost-effective, the necessary resources must be available, it must produce an excess of energy, it must be safe, and it must be ecologically acceptable. The first three requirements can be met by using a two-component structure consisting of solid-fuel thermal and fast reactors. In this structure natural resources (uranium and/or thorium) can be used much more efficiently, the production of uranium can be decreased, and therefore the amount of radon entering the biosphere can be decreased. The ways to achieve the required level of expanded production of fuel, to increase safety, and to decrease capital costs for both types of reactors are now well known, and only time and the means are required for implementing them. By the time society realizes the need for developing nuclear power, the technology for a two-component structure will actually be ready, though much will still have to be done in order to optimize nuclear power as well as the structure of the industry, including enterprises in the nuclear fuel cycle.Difficulties could arise with public acceptance of the level of the ecological effect. This will in many ways be determined by the quantity of radionuclides both in the fuel cycle (uranium, plutonium) and in the burial sites (Np, Am, Cm, other actinides, and fission products) as well as globally disseminated radionuclides (14C, T, 85Kr). 'It is now already possible to show that the risk from short-lived radionuclides (for example, 131I) as well as radionuclides of the type 9~ and 137Cs can be lowered to an acceptable level by meeting the required safety standards for nuclear power plants, burial sites, and enterprises in the fuel cycle. Ways to decrease carbon, tritium, and krypton emissions into the atmosphere are now known. The acceptability of such a risk can be demonstrated in practice or indirectly (for example, by showing that different barriers remain functional for hundreds and thousands of years). However, it is difficult to prove and impossible to demonstrate the reliability of the burial of long-lived actimdes and fission products for millions of years.Undoubtedly, the search for ways to bury relial~ly radioactive wastes must continue, but the possibility of using actinides to produce energy (rather than storing them), i.e., of closing the fuel cycle not only with respec...

Cascade subcritical liquid-salt reactor for burning transplutonium actinides

“…It has been suggested that the principle of cascade multiplication of neutrons in two-section blankets be used to decrease the power requirements of the driving accelerator [6,7].…”