Approval of American Society of Mechanical Engineers Unconditioned Code Cases

Document 2025-18769 is a Final Rule published by the Nuclear Regulatory Commission in the Federal Register on September 26, 2025, with an effective date of January 26, 2026. The U.S. Nuclear Regulatory Commission (NRC) is amending its regulations to incorporate by reference a regulatory guide that approves unconditioned code cases published by the American Society of Mechanical Engineers (ASME). This action allows nuclear power plant applicants and licensees to use the code cases as voluntary alternatives to engineering standards for nuclear power plant components. These standards are set forth in the ASME Boiler and Pressure Vessel Code and ASME Operation and Maintenance of Nuclear Power Plants, which are currently incorporated by reference into the NRC's regulations. View the original at https://www.federalregister.gov/documents/2025/09/26/2025-18769/approval-of-american-society-of-mechanical-engineers-unconditioned-code-cases.

No. Document 2025-18769 is not classified as economically significant under Executive Order 12866. Economically significant rules require OIRA review and are estimated to have impacts of $100 million or more per year.