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.