Toward developing a novel combined Licensing & Safety approach for advanced nuclear reactors based on the international maritime and nuclear safety framework. Case study of the CMSR Power Barge

The Compact Molten Salt Reactor (CMSR), being developed by Seaborg Technologies, is a SMR and as per its name is characterized by a core in which the fuel is in a molten state dissolved in fluoride salts. The CMSR is integrated into a floating non-self-propelled barge (covering the milestone phase to decommissioning lifecycle). Molten salt reactors such as the CMSR cannot melt down and offer significant advances and advantages compared to solid fuel LWRs. Most of the technology neutral IAEA safety guidelines were developed based on LWRs. Furthermore, the SMR characteristics of the CMSR combined with its transportability in maritime environment represent new licensing opportunities based on the International Maritime Organization (IMO) framework. In the absence of a consistent and harmonized framework to enable international licensing and safety considerations for SMRs and specifically for the CMSR combining SMR, maritime, innovative nuclear design and existing nuclear safety approaches, Seaborg is taking a proactive step toward proposing a novel combined licensing & safety approach. The Seaborg approach is based on the issuance of an International Licensing & Safety Case covering both the Seaborg safety approach and the Seaborg licensing approach. The Seaborg safety approach integrates in a systematic and traceable manner international and relevant recognized national guidelines. Requirements are redefined when relevant to the CMSR to provide a basis combining deterministic and probabilistic approach through a deliberative process justifying a risk informed performance-based approach to safety. The Seaborg licensing approach with the involvement of international stakeholders and recognized IMO framework addresses an important number of IAEA recommended functions and processes traditionally associated with the licensee and host state authorities. This approach covers the development of IAEA milestones and up to and including decommissioning aspects. The added benefits of the Seaborg licensing approach are to lessen the burden on licensee and host state authorities, and providing a predictable licensing path for all stakeholders. Furthermore, this is facilitated by the reduced site-specific considerations of the CMSR and its transportability, SMR serial and standardized production aspects increasing efficiency, safety and lessons learned, shipyard-fuelled improving safeguards, harmonized integration of operating experiences, experienced supply chain, etc. While lessening the burden on the licensee and host state authorities, by means of digital transparency and traceability and the Seaborg licensing process itself, licensee and host state authorities retain an overview and required capabilities to understand and intervene for all matters related to safety throughout the whole lifecycle of the CMSR when necessary and relevant. The development of the combined Seaborg Licensing and Safety approach is an opportunity for the development of SMRs. It provides a systematic safety & licensing roadmap applicable to other SMRs particularly micro and mobile reactors. Additionaly, it provides a basis for discussion and recommendations for the improvement of the existing IAEA and IMO frameworks to facilitate future SMRs development including consideration by the international community of non-safety relevant provisions or absence thereof, strengthen safety, and increase international cooperation for the peaceful use of nuclear energy tailored to SMRs and associated non-traditional use and actors. (author)