Several nuclear energy newcomer countries have become interested in small modular reactors (SMRs) as a nuclear energy source to meet growing electricity demand, given the heightened concerns about greenhouse gas emissions. While SMR technology lowers the threshold for newcomer countries, it can generate new uncertainties about future nuclear proliferation risks. Therefore, this study seeks to determine whether future SMR nuclear trade will contribute to nuclear proliferation, and how the risks can be mitigated. This research uses the Bayesian network (BN) approach in conjunction with surveys of experts to assess nuclear proliferation risks when newcomer countries deploy SMRs. In this study, we perform a comprehensive assessment of the general nuclear energy newcomer country in terms of non-proliferation infrastructure, the country’s economic and commercial electric grid capacity, the unique characteristics of SMRs, enrichment and spent nuclear fuel management plans. By modeling the risks for future SMR deployment and clarifying the solutions, the findings of this research will provide recommendations for policymakers in the United States and abroad seeking to promote peaceful nuclear cooperation while reducing nuclear proliferation risks.