Nonproliferation improvements and challenges presented by small modular reactors

• This paper examines how SMRs challenge and improve the existing nonproliferation regime.
• Discusses technical aspects of SMR designs in the context of proliferation concerns.
• Offers a number of recommendations to help alleviate proliferation concerns that may arise due to SMR design features.

Small modular reactors (SMRs) may provide an energy option that will not emit greenhouse gases. From a commercial point-of-view, SMRs will be suitable to serve smaller energy markets with less developed infrastructure, to replace existing old nuclear and coal power plants, and to provide process heat in various industrial applications. In this paper, we examine how SMRs might challenge and improve the existing nonproliferation regime. To motivate our discussion, we first present the opinions gathered from an international group of nuclear experts at an SMR workshop. Next, various aspects of SMR designs such as: fissile material inventory, core-life, refueling, burnup, digital instrumentation and controls, underground designs, sealed designs, enrichment, breeders, excess reactivity, fuel element size, coolant opacity, and sea-based nuclear plants are discussed in the context of proliferation concerns. In doing this, we have used publicly available design information about a number of SMR designs (B&W mPower, SVBR-100, KLT-40S, Toshiba 4S, and General Atomics EM2). Finally, a number of recommendations are offered to help alleviate proliferation concerns that may arise due to SMR design features.