Unique Safety Features and Licensing Requirements of Small Modular Reactors

Small modular reactors (SMR) cover a wide range of concepts: from smaller cousins of classical light water reactors to advanced types using molten salts. While offering the promise of standardized designs and the prospect of economies of scale and scope in manufacturing and licensing their unique safety features require an initial, one-off effort to demonstrate safety to regulators and investors.

On the one hand, smaller and compacter designs mean less components, but on the other hand, it is closer proximity of essential ones and a denser system integration. Hence, new, dedicated experimental facilities are necessary to evaluate safety properties and transient behavior and to validate simulation codes.

New fuel types like higher enrichment up to 20% w/o U235 or new fuel materials like molten salts or tri-structured isotropic particles require new and dedicated safety standards as well as in-depth safety demonstrations. Therefore, a broad range of activities are ongoing worldwide to bring these concepts to fruition.

Modern simulation tools ranging from full core Monte Carlo calculations to sophisticated computational fluid dynamics applications offer the opportunity to determine safety margins and predict system performance with hitherto unmatched accuracy. Nevertheless, licensing requires code validation and high quality codes together with modern experimental facilities offer the opportunity to set new standards in reactor performance predictability.

The objective of this Research Topic, therefore, is to cover the broad spectrum of development and research activities for SMRs in a dedicated journal section and to highlight their unique operaton and safety features.

Additionally, contributions from regulators or their technical support organizations highlighting the unique regulatory challenges are invited. Also, perspectives from potential investors and end-users of SMRs addressing their decision maker needs are welcome.

For this Research Topic, we would like to collect papers on the following, but not limited to:
- Transient analyses demonstrating the unique safety profile of SMRs
- Dedicated experiments and benchmarks to validate simulation codes for SMRs
- Safety analysis of nuclear fuel design for SMRs
- Advanced fuel properties for SMRs and experimental demonstration of safety
- High performance computing simulations dedicated to SMR reactor performance
- Unique regulatory challenges to license SMRs within existing rules and regulations
- Investors' perspective on requirements for SMR deployment

Topic Editor Dr. Cesare Frepoli is the founder of FPoliSolutions LLC. Topic Editor Dr. Dong-Yuan Sheng receives partial financial support from Westinghouse LLC. The other Topic Editors declare no competing interests with regard to the Research Topic subject.