Document: NUREG-0800
Document ID: 164d26ee-2125-481e-9fae-fb7b05365716
Document Type: srp
Title: RESIDUAL HEAT REMOVAL (RHR) SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340635.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.7
CFR Part: 
CFR Title: 

Content:
ews the processes and systems used in the cooldown of the reactor for the entire spectrum of potential reactor coolant system pressures and temperatures during decay heat removal. 2. For PWRs, the RSB reviews the approach used to meet the functional requirements of BTP RSB 5-1 with respect to cooldown to the conditions permitting operation of the RHR system. Since an alternate approach to that normally used for cooldown may be specified, the reviewers identify all components and systems used. The CMEB has primary review responsi- bility for the review of the pertinent portions of the CVCS (SRP Section 9.3.4). The ASB, as part of its primary review responsibility for SRP Sections 10.3 and 10.4.9 reviews the atmospheric dump valves and the source for auxiliary feedwater, respectively, for conformance to BTP RSB 5-1. The RSB reviews the pressurizer relief valve and ECCS, if used. In addition, the RSB reviews the tests and supporting analysis concerning 5.4.7-2 Rev. 3 - April 1984 mixing of borated water and cooldown under natural circulation as required in BTP RSB 5-1. 3. For both PWRs and BWRs, the ASB reviews the component cooling or service water systems that transfer decay heat from the RHR system to the ultimate heat sink as part of its primary review responsibility for SRP Sections 9.2.1 and 9.2.2. 4. The RSB reviews the design and operating characteristics of the RHR system with respect to its shutdown and long-term cooling function. Where the RHR system interfaces with other systems (e.g., RCIC system, component cooling water system) the effect of these systems on the RHR system is reviewed. Overpressure protection provided by the valving between the RCS and RHR system is also reviewed. In addition, the Reactor Systems Branch will coordinate evaluations of other branches that interface with the overall review of the RHR system as follows: The Containment Systems Branch verifies that portions of the RHR system pene- trating the containment barrier are designed