Specifics of SMRs Development and Deployment

Abstract

It is important to understand the technology status and design specifics for efficient, economic, and safe implementation of Small Modular Reactors (SMRs) (usually, installed capacities ≤300 MW ) in the nuclear-power industry, which are today's a very "hot" topic in the nuclear el engineering worldwide. In general, there are about 108 concepts / designs of SMRs with almost all at their current stages of development / deployment being variants of current or well-known types of reactors, which can be classified as PWRs, BWRs, PHWRs, SFRs or next generation - Generation-IV reactor concepts, i.e., VHTRs, GFRs, SFRs, LFRs, MSRs, and SCWRs with some based on using heat pipes. Irrespective of technology, smaller reactors are often also labeled as “Advanced Reactors (ARs)” or Generation IV to somehow distinguish them from existing LWR technology and, hence, subject to different licensing rules, safety analyses, and approaches including new Licensing-Basis Events (LBEs). The paper discusses the implications of extensive use of such terminology as “passive safety”, natural circulation, and “inherently safe” for long-term cooling systems, and the key need to address the “licensability” of unconventional systems and arguments based on the Risk Informed Decision Making (RIDM). First four SMRs of two different types in operation are connected to subcritical-pressure Rankine steam-turbine power cycles of various options. Therefore, these and other specifics of the SMRs' designs are discussed in the paper.