Document: NRC Regulatory Guide
Document ID: 60ac4a53-3f72-4e92-9ad2-39c736cf2135
Document Type: regulatory_guide
Title: Functional Specification for Active Valve Assemblies in Systems Important to Safety in Nuclear Power Plants
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003739979.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.148
CFR Part: 
CFR Title: 

Content:
a result of the 1972 meeting, effort on developing valve operability standards was initiated under the auspices of the American National Standards Institute Committee N45. Subsequently, this standards development responsibility was transferred to B 16 Subcom mittee H. The first of these standards to be published was ANSI N278.1-1975, "Self-Operated and Power-Operated Safety-Related Valves Functional Specification Standard." The regulatory guide endorses that standard with suggested supplemental guidance. Value Although ANSI N278.1-1975 provides requirements important for adequate definition of valve assembly applica tion and operating conditions, the standard, by itself, will not provide complete assurance of valve assembly operability. It is anticipated that the most important contributions from ANSI N278.1-1975 will be realized when subsequent standards, which are currently being developed to address such topics as valve assembly functional qualification and production testing, are in place to provide a set of require ments covering various aspects of valve assembly operability. However, endorsement of ANSI N278,-1975 as supple mented by the regulatory position of the guide will provide a uniform basis and approach for specifying the functional requirements and operability considerations for any partic ular valve assembly that has a safety-related function. The guide also emphasizes the need for a set of compre hensive requirements covering construction, operability, and inservice testing of active valve assemblies in systems important to safety. Impact The impact of this regulatory guide is expected to be rather limited because licensees are committed to a program to demonstrate valve assembly operability in accordance with Sections 3.9.3.2 and 3.9.6 of Regulatory Guide 1.70, Revision 3, "Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants." Additionally, all applicants are cognizant of NRC staff positions on valve assembly operability