NRC Closes Public Comment Period on Fusion Regulatory Framework — Final Rule Targeted Fall 2026

The U.S. Nuclear Regulatory Commission's 90-day public comment period on its proposed 'Regulatory Framework for Fusion Machines' closed approximately May 27, 2026, with Axios reporting on May 22 that fusion energy is 'poised for simpler U.S. review.' The proposed rule (Federal Register, February 26, 2026; Docket ID NRC-2024-0199) would formally classify fusion reactors under Part 30 — the byproduct material regulations — a significantly simpler licensing pathway than the Part 50/52 framework historically applied to fission reactors. A final rule is targeted as early as fall 2026. The framework codifies what physicists have long argued: fusion machines cannot sustain runaway chain reactions and do not produce long-lived high-level nuclear waste, making fission-derived licensing requirements scientifically inappropriate. If finalized, the rule would allow fusion companies like Commonwealth Fusion Systems and Helion Energy to license commercial plants on timescales of years rather than decades, removing one of the most-cited structural barriers to the commercial fusion timeline. The proposed framework has been informed by 40+ years of tokamak and inertial fusion research, input from the DOE, Fusion Industry Association, and the 43+ private fusion companies now operating globally. For CFS, which filed the first fusion grid interconnection application with PJM on April 28, a clear federal licensing pathway is critical for finalizing power purchase agreements and project financing for its ARC commercial plant in Virginia.