Energia i regulacje · 13/05/2005

Proposed Generic Communication; Clarification of Post-Fire Safe-Shutdown Circuit Regulatory Requirements

The U.S. Nuclear Regulatory Commission (NRC) is proposing to issue a regulatory information summary (RIS) to clarify regulatory requirement issues associated with post-fire safe-shutdown circuit analyses and protection, particularly the requirements of Title 10 of the Code of Federal Regulations, Part 50 (10 CFR 50), Appendix R, which have been interpreted by licensees in a manner that is not consistent with regulatory expectations. The industry and NRC regional inspectors have requested clarification of regulatory expectations with respect to post-fire safe-shutdown circuits. In addition, clarification of these requirements will assist licensees in evaluating the transition to a risk-informed, performance-based fire protection program. Three terms are to be addressed in this RIS: "any-and-all" (with respect to spurious actuations), "associated circuits," and "emergency control station." Clarification of the term "one-at-a- time" (with respect to spurious actuations) will be provided in a separate generic communication. For each term addressed, this RIS identifies the applicable NRC regulatory requirement, provides the regulatory expectation with respect to the requirement, and spe