Document: NUREG-0800
Document ID: bb823f40-ee8a-48c3-b347-aa5265dc04e4
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0704/ML070460345.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
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 # ML070460345. NUREG-0800 U.S. NUCLEAR REGULATORY COMMISSION STANDARD REVIEW PLAN BRANCH TECHNICAL POSITION 7-1 GUIDANCE ON ISOLATION OF LOW-PRESSURE SYSTEMS FROM THE HIGH-PRESSURE REACTOR COOLANT SYSTEM REVIEW RESPONSIBILITIES Primary - Organization responsible for the review of instrumentation and controls Secondary - None A. Background During normal and emergency conditions, it is necessary to keep low-pressure systems that are connected to the high-pressure reactor coolant system properly isolated in order to avoid either damage by overpressurization or the loss of integrity of the low-pressure system and possible radioactive releases. The residual heat removal system used for cold shutdown conditions when in service becomes an extension of the reactor coolant pressure boundary. General Design Criterion 15 requires that reactor coolant system and associated auxiliary, control, and protection systems shall be designed with sufficient margin to ensure that the design conditions of the reactor coolant pressure boundary are not exceeded during any condition of normal operation, including anticipated operational occurrences. There have been loss of decay heat removal during nonpower operation incidents and they have been a concern for years. NRC issued Generic Letters (GL) 87-12 and GL 88-17 for licensees to perform a systems analysis to avoid these problems. There have been a number of recommendations for accomplishing this aim. Until a more definitive guide is published, the criteria in Part B, below, provide