System features of fast sodium reactors in a two-component structure of nuclear power generating

Abstract

The stepwise conversion of Russian nuclear power industry to a two-component nuclear energy system (NES) with thermal and fast reactors in a single closed NFC allows a number of deferred system problems of modern power industry to be solved, such as accumulation of spent fuel from thermal reactors and spent fuel repatriated from foreign Russian-designed NPPs; inefficient use of highly limited raw uranium inventories; recycling of minor actinides and other long-lived high-level waste accumulated in the course of thermal reactors’ operation. The paper examines the fundamental capabilities of two-component NES, which appear due to the availability of commercial fast neutron sodium reactors. Due to the synergistic development of thermal and fast reactors, it is expected to achieve an economic effect associated with introduction of new fuel services in the nuclear energy system, such as production of plutonium and improvement of its isotopic composition for thermal reactors, transmutation of “external” minor actinides, production of isotopes for various purposes, production of hydrogen, etc. The expansion of Russia’s export opportunities is also being considered, it can be done through fuel supply for both power units built in compliance with Russian technologies and foreign power units with MOX fuel. In this approach, it is important to analyze the economy of the whole system, where fast reactors, due to their inherent surplus of neutrons, perform the functions required to the entire NES, rather than to analyze the technical and economic indicators of individual reactors. The article makes a preliminary technical and economic assessment of such system functions provided by fast sodium reactors. It is shown that fast and thermal reactors operating together in a two-component nuclear energy system, with the same electrical power and similar technical and economic indicators, can significantly reduce the necessary infrastructure costs and/or generate additional income, thereby reducing the specific levelized cost of electricity production.