NRC issues risk-based change guide for nuclear plant operators

The Nuclear Regulatory Commission, or NRC, issued Regulatory Guide 1.261 on June 11, 2026. It says staff will accept a technology-inclusive, risk-informed change evaluation process for changes to a facility described in updated final safety analysis reports.

That matters because nuclear plants do not change on paper alone. When operators upgrade equipment, revise procedures or make other modifications, they need a federal way to judge whether the change still fits the plant’s safety basis. In plain English, the guide gives them a recognized method for taking risk into account before they make that call.

A safer shorthand for change

Subject to the clarifications in Section C, the guide endorses Nuclear Energy Institute 22-05, Revision 0, also called Technology-Inclusive Risk-Informed Change Evaluation, or TIRICE. The NRC says that methodology is an acceptable alternative to using the criteria in 10 CFR 50.59, the existing rule for changes, tests and experiments.

The agency is drawing that line because some plants licensed under newer, more technology-inclusive frameworks rely more heavily on probabilistic risk assessment than the older parts 50 and 52 structure. That means the familiar change test may not fit those plants neatly. This guide is the NRC’s way of saying a different, risk-informed route can work.

What operators gain

The guide is not a blanket command. The NRC says licensees generally are not required to comply with Regulatory Guide 1.261. Instead, it gives plant owners, engineers and reviewers a shared federal reference point for deciding whether a proposed change can be handled through a technology-inclusive review.

For operators, the practical value is clarity. The guide spells out an acceptable approach for evaluating changes to facilities described in updated final safety analysis reports, which can help align internal reviews, outside technical work and NRC expectations when a facility wants to modernize without drifting outside its approved safety basis.