NANO Nuclear Endorses NRC’s Part 53 Rule Effective April 29 for KRONOS MMR Licensing
NRC’s Part 53 final rule, effective April 29, 2026, establishes a risk-informed, performance-based optional licensing pathway aimed at advanced reactor designs like NANO Nuclear’s KRONOS MMR microreactor. The NRC’s proposed Part 57 framework would support standardized, factory-built, multi-site deployments with reduced emergency planning and accelerated licensing timelines.
1. NRC Finalizes Part 53 Rule
The NRC’s new Part 53 rule becomes effective April 29, 2026, offering an optional, risk-informed, performance-based licensing pathway. This framework complements existing Part 50 and 52 processes by aligning with inherent safety features of advanced reactors and promising more flexible, predictable licensing for designs such as the KRONOS MMR.
2. Proposed Part 57 Microreactor Framework
The proposed Part 57 rule targets microreactors, introducing combined construction and operating licenses, recognition of factory fabrication, standardized design approvals, reduced emergency planning and alternative siting. These measures aim to streamline repeatable, fleet-scale deployment of systems like the KRONOS MMR.
3. Applicability to NANO’s KRONOS MMR Deployment
NANO Nuclear is evaluating Part 53 and 57 for future commercial projects, while its initial KRONOS MMR deployment at the University of Illinois Urbana-Champaign will proceed under Part 50. The company expects new frameworks to enhance efficiencies for subsequent standardized, multi-unit rollouts.
4. Ongoing Industry Engagement
NANO Nuclear is actively reviewing both frameworks and collaborating with the Nuclear Energy Institute and other stakeholders. Leadership believes these rules will support scalable commercialization of its microreactor technologies by emphasizing modularity, inherent safety and reduced regulatory hurdles.