The minor actinides are transuranic elements (except plutonium), formed during operation of nuclear reactor. Despite of the fact that total volume of their generation is low, many minor actinides are alpha-emitters with very long half-life (hundreds, thousands, and even millions of years), which makes them one of the most hazardous components of processed nuclear fuel in the long term.
“Currently, burial of nuclear waste is not the best or cheap technology. Therefore, the idea of such reactor is that by molten salts we can partially dissolve waste, i. e. by adding there fuel components, plutonium, for instance, or to use decay and transmutation of the minor actinides, for supporting a neutron reaction. By doing this during certain time, but not long, we support controlled rate of transmutation of the minor actinides. At the end of the day, we will have substantial reduction of highly active waste volume”, – he noted.
Such reactor will factually be a metallurgical furnace, whereby reactions of radiation interaction will take place, fitted with a heat exchanger and an add-on salt purification module, which is intended for recycling of the minor actinides. Due to this module, a portion of the highly active waste will be removed and some portion of the salts will go back to the reactor.
Now the pilot samples are being studied. In the future, by late 2030-ies – early 2040-ies we might construct already a large industrial reactor, capable of providing the transmutation of no less than 250 kg of minor actinides per year. Concurrently, heat rating of such reactor might reach around 1 GW.
Creation of the molten salt reactor will require a fundamental change of the current regulatory framework, usage of new structural materials and application of high-tech robotics, since the very processes, running in the reactor, are harsh and hazardous.
“At the end, we will still have remaining some quantity of highly active waste, but it will be one order less than now. Those countries, which already possess the processed nuclear fuel, can with the aid of this technology, substantially reduce the waste volumes. The balance of activity will stay, but in very low volume, therefore waste burial will be noticeably less capital intensive”, – noted A. Dub.
