Document: NUREG-0800
Document ID: c755e557-3a72-423f-92bc-0f0270936e27
Document Type: srp
Title: RESIDUAL HEAT REMOVAL (RHR) SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1006/ML100680577.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.7
CFR Part: 
CFR Title: 

Content:
that the applicant has reviewed its RHR system design configurations to identify any piping connected to the RCS that could be subjected to temperature distributions that could result in unacceptable thermal stresses. This review should consider the potential for thermal stratification, thermal cycling, and thermal fatigue, given the RHR system configuration. The reviewer verifies that appropriate action has been taken, where such piping is identified, to ensure that the piping will not be subjected to unacceptable thermal stresses (see NRC Bulletin 88-08). This review should focus on RHR system configurations; the organization responsible for mechanical engineering reviews under SRP Section 3.9.3 reviews the stress analysis and ensures that it conforms to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code. 22. The NRC states its regulatory position with respect to minimizing the potential for an intersystem LOCA in advanced or evolutionary light-water reactors in SECY-90-016 and SECY-93-087 and their associated SRM. In keeping with that position, the reviewer will verify that, to the extent practical, the RHR system for advanced or evolutionary light- water reactors is designed to an ultimate rupture strength at least equal to the normal RCS operating pressure. All elements of the RHR system are to be considered (e.g., instrument lines, pump seals, heat exchanger tubes, valve bonnets) The licensee should provide justification for elements not designed to an ultimate rupture strength at least equal to the normal RCS operating pressure. 23. Some advanced light-water reactor (ALWR) designs make extensive use of passive systems to meet regulatory requirements. Often, they include a nonsafety-related active system for use during normal plant operation and to provide defense in depth to the safety-related passive system. The nonsafety-related active systems are the first line of defense to reduce challenges to the passive systems in the event