Technology readiness assessment of Small Modular Reactor (SMR) designs

• We make a technology readiness assessment on LWR-based SMRs.
• SMRs' main approaches to enhanced safety, economy and operability are identified.
• The maturity of SMRs' key systems and components is analyzed.
• The higher integration of primary system is the biggest challenge in SMR development.

Small Modular Reactor (SMR) is an emerging energy technology that meets the demand of safety, efficiency and sustainability. This paper reviews the representative SMR designs. Comparisons are made between each current SMR and its originating design, obtaining a summarization of the development course and the innovation features of each SMR version. To get a comprehensive understanding of SMR, this paper suggests a bidirectional assessment method. In the longitudinal direction, assessments focus on technology evolution, especially SMR's approaches to safety and its responses to Fukushima accident. In the transversal direction, a breakdown of SMR leads to the detailed assessment of its systems and equipments, thus identifying the maturity and inadequacy of a certain SMR design. Based on empirical analysis, this paper suggests an approximate ten year effort be needed for the leading light water reactor (LWR) based SMR to solidify the final form and operate under the full range of commissioning conditions.