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NRC introduces microreactor regulatory framework
The Nuclear Regulatory Commission has released a new licensing framework for microreactors and similar reactor designs that may provide a more suitable pathway for applicants with simpler technologies.
The proposed rule—known as Part 57—is the latest to come out of the NRC’s rules review and overhaul stemming from the ADVANCE Act and 2025 nuclear-related executive orders. It is also the latest framework developed for advanced reactor designs shifting away from light water reactor technology, such as the Part 53 rule finalized in March.
Alexis Maldonado, Christopher Perfetti
Nuclear Science and Engineering | Volume 197 | Number 8 | August 2023 | Pages 2086-2098
Technical papers from: PHYSOR 2022 | doi.org/10.1080/00295639.2022.2162782
Articles are hosted by Taylor and Francis Online.
When designing experiments for full-scale reactor systems, the Monte Carlo N-Particle® and Whisper codes can be used to create neutronic models and compare the similarity of two nuclear systems via correlation coefficients for , the effective multiplication factor. This paper applies this framework to a conceptual heat pipe yttrium-hydride-moderated microreactor system and experiments, but the method can be applied generally to any nuclear reactor design. The framework is intended as a supplement to other neutronics/thermal/multiphysics analyses and provides an objective method to measure the neutronic similarity of two systems. By analyzing the shared nuclear data uncertainty, as well as sensitivity to nuclear data over all neutron energies, highly informative experiments can be designed to aid in the development of microreactor and other advanced reactor technologies and systems.