Document: NUREG-0800
Document ID: c8f36c26-ea0c-4666-a961-26a96c5ac239
Document Type: srp
Title: Revision 3 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070710452.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
lear Regulatory Commission, Washington, DC 20555, Attention: Reproduction and Distribution Services Section, or by fax to (301) 415-2289; or by email to DISTRIBUTION@nrc.gov. Electronic copies of this section are available through the NRC's public Web site at http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/, or in the NRC's Agencywide Documents Access and Management System (ADAMS), at http://www.nrc.gov/reading-rm/adams.html, under Accession # ML070710452. NUREG-0800 U.S. NUCLEAR REGULATORY COMMISSION STANDARD REVIEW PLAN BRANCH TECHNICAL POSITION (BTP) 8-4 APPLICATION OF THE SINGLE FAILURE CRITERION TO MANUALLY CONTROLLED ELECTRICALLY OPERATED VALVES REVIEW RESPONSIBILITIES Primary - Organization responsible for electrical engineering Secondary - None A. BACKGROUND When a single failure in an electrical system can result in a loss of capability to perform a safety function, the effect on plant safety must be evaluated. This is necessary regardless of whether the loss of safety function is caused by a component failing to perform a requisite mechanical motion or by a component performing an undesirable mechanical motion. This position establishes the acceptability of disconnecting power to electrical components of a fluid system as one means of designing against a single failure that might cause an undesirable component action. These provisions are based on the assumption that the component is then equivalent to a similar component that is not designed for electrical operation (e.g., a valve that can be opened or closed only by direct manual operation). These provisions also assume that no single failure can both restore power to the electrical system and cause mechanical motion of the components served by the electrical system. The validity of these assumptions should be verified when applying this position. BTP 8-4-2 Revision 3 - March 2007 B. BRANCH TECHNICAL POSITION 1. Failures of components in electrical systems, including valves and other