Considerations For Proliferation Resistance And Physical Protection Of Small Modular Reactors

Global interest in small modular reactors (SMRs) has been increasing due to their ability to meet the needs of a wider range of users and applications. In addition to exhibit advanced design and safety features, SMRs also provide flexibility in terms of location of deployment since they may serve regions that are more difficult to support with other clean energy systems, like large nuclear power plants. These can be off-grid areas difficult to access, remote islands, or sparsely populated regions with small electric grids and limited infrastructure. This is the case of some nuclear embarking countries. Furthermore, deployment of several small modular reactors on one site and the mode of shipment of fully assembled reactors, may have an impact on the proliferation resistance and physical protection (PR&PP) of SMRs and their associated fuel cycles. These deployment schemes must be also carefully examined against the required higher enrichment or reduced core power density. Most of the marine-based SMRs and microreactors adopt long life reactor core with the purpose to achieve long refueling periods; this may also increase proliferation resistance. The paper will emphasize certain design features and characteristics that can have impact on PR & PP of SMRs. Some designs adopt a containment system shared by multiple modules installed underground. These may enhance PR&PP yet complicate safeguards inspection. Hence, focus will be put on understanding the implication of such design features on PR&PP, with possible consideration of the safeguards-by-design (SBD) approach. The overall scope of the SBD is wide, and it is mainly an approach whereby early consideration of international safeguards is included in the design process of a nuclear facility, allowing informed design choices that are the optimum confluence of economic, operational, safety and security factors, in addition to international safeguards. These specific aspects relevant to SMRs will be discussed.