Document: NUREG-0800
Document ID: d0e1f2cb-f296-449d-9f9a-85a571917a44
Document Type: srp
Title: EMERGENCY CORE COOLING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340709.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.3
CFR Part: 
CFR Title: 

Content:
er. Regarding the effects of pressure, temperature, etc., the RSB reviewer should confirm that accident conditions are specified which provide the basis for proof tests for environmental qualification of ECCS components, 6. The criteria, supporting analyses, plant design provisions, and operator actions that will be taken are reviewed to ensure that there will not be unacceptably high concentrations of boric acid in the core region (result- ing in precipitation of a solid phase) during the long-term cooling phase following a postulated LOCA. 6.3-6 Rev. 2 - April 1984 7. The ECCS design is reviewed to confirm that there are provisions for main- tenance of the long-term coolant recirculation and decay heat removal systems, e.g., pump or valve overhaul, in the post-LOCA environment (including consideration of radioactivity). 8. The availability of an adequate source of water for the ECCS is confirmed, and the source volume, location, and susceptibility to failure (e.g., freezing) are evaluated. (RSB will request ASB review as required.) In PWRs, the piping from the water source to the ECCS safety injection pumps is evaluated for conformance with RSB 6-1 (Ref. 13). 9. The ECCS flow paths are reviewed to determine the extent to which flow from the ECCS pumps is diverted as a backup feature to other safeguards equipment (e.g., RHR, containment spray). The reviewer should confirm that the remaining portion of the flow provides abundant core cooling, despite the most severe single failure that affects ECCS flow. 10. For a boiling water reactor (BWR), the reactor coolant automatic depressurization system is reviewed to confirm the capability to satisfy LOCA pressure relief functions, including consideration of a single failure. 11. The design of ECCS injection lines is reviewed to confirm that the isolation provisions at the interface with the reactor coolant system are adequate. The number and type of valves used to form the interface between low pressure portions of the