Approval of American Society of Mechanical Engineers Unconditioned Code Cases

What it does

The U.S. Nuclear Regulatory Commission (NRC) is confirming the effective date of January 26, 2026, for the direct final rule that was published in the Federal Register on September 26, 2025. This direct final rule amended the regulations to incorporate by reference a regulatory guide that approved unconditioned code cases published by the American Society of Mechanical Engineers. 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.

The Nuclear Regulatory Commission's summary, as published in the Federal Register.

What changed in the regulation

1 part of Title 10 of the Code of Federal Regulations:

10 CFR 50

Wording on eCFR: the day before it took effect and from the day it took effect (first part listed).

Compared with

The Nuclear Regulatory Commission has published 34 final rules in 2026 so far, compared with 28 in all of 2025.

Counted by the Tribune from Federal Register records since Jan. 1, 2025.

Before this

2 earlier Federal Register documents under regulation identifier 3150-AL20 since Jan. 1, 2025.

• Sept. 26, 2025 Direct final rule. Approval of American Society of Mechanical Engineers Unconditioned Code Cases
• Sept. 26, 2025 Proposed rule. Approval of American Society of Mechanical Engineers Unconditioned Code Cases

What happens next and when

The effective date of January 26, 2026, for the direct final rule published September 26, 2025 (90 FR 46319), is confirmed. The incorporation by reference of certain material listed in the regulation is approved by the Director of the Federal Register as of January 26, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket NRC-2024-0163 on Regulations.gov
• Title 10 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register