Reactor Cores for Small-Sized Nuclear Power Plants (SNPP) and Floating Power Units (FPU)

Abstract

The Russian Federation, acting through ROSATOM, is rapidly developing small and medium-sized nuclear power industry on the basis of Small Modular Reactors (SMR). This segment of power industry is primarily aimed at supplying electric power to remote (including northern and island) territories, as well as areas with decentralized power supply. At present, the Russian Federation operates the floating power unit Akademik Lomonosov with KLT-40S reactor plants and 14–14 cores, and a series of multi-purpose nuclear-powered icebreakers (MNI) with RITM-200 reactor plants and 14–15-1 cores. The designs of the above-stated cores were taken as a basis for the development of the AS-14–15 core of the RITM-200N reactor plant for an SNPP and of the 14–17 core of the RITM-200S reactor plant for an upgraded floating power unit (UFPU), which was completed in 2022. Each type of the reactor cores has a number of specific features defined by the requirements for reliability (lifetime, stored energy, load following capability, etc.) and safety. The scope of work performed to justify the design performance capability and the lifetime characteristics includes: extensive calculations using verified and certified computational codes, comprehensive development work at the OKBM’s test facilities, as well as years long irradiation tests carried out in the reactors of nuclear icebreakers and in the nuclear research reactor loop-type facilities with subsequent post-irradiation examinations. The basic design development of the reactor cores for the FPU with RITM-400M reactor plant (the Arctic version) and for the optimized floating power unit (OFPU) with RITM-200M reactor plant (the Tropical version) is currently underway. The outlined reactor cores have a reserve for a wide variety of characteristics and functional applications.