Examination of proliferation resistance of small modular reactor by using barrier-based fuzzy logic method

In the current global warming situation, the deplopment of small modular reactor (SMR) is obviously an effective solution for sustainable energy development. On the other hand, in the light of global public concern regarding the misuse of nuclear material and proliferation, the evaluation of proliferation resistance (PR) of a nuclear fuel cycle is clearly important. Considering SMRs are still at the conceptual design stage, an assessment of their PR value is complicated by the lack of detailed design information. Still a PR analysis can be adequately performed by using an attribute approach. In this research, the PR values for three SMRs were examined using the barrier-based fuzzy logic method. This method is based on a barrier framework, which includes 11 intrinsic proliferation barriers. This method was applied to three kinds of potential proliferators: 1) sophisticated state in an overt breakout (SSO), 2) sophisticated state in a covert breakout (SSC), and 3) unsophisticated state in a covert breakout (USC). Assessment results from this analysis were verified using a nonproliferation assessment tool (NAT) and its utility functions. To analyze the effects of potential bias issues, a sensitivity analysis of the calculated weighting factors, for each proliferation barrier, was performed. According to the PR assessment results, the reactor operation process of SMRs have higher PR values in comparison with other types of nuclear reactors. Consequently, the deployment of SMRs will not provide a potentially vulnerable target for proliferators. Based on these results, recommendations regarding the potential design options of an SMR were proposed to strengthen the PR values. The SMR safeguards enhancements suggested by this research were discussed from the perspective of minimizing the safeguards burden (i.e., number of onsite visits) on the International Atomic Energy Agency