Document: NUREG-0800
Document ID: ea7ce8f5-32bf-4d8c-a653-e964bff0ef48
Document Type: srp
Title: EMERGENCY CORE COOLING SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070448.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.3
CFR Part: 
CFR Title: 

Content:
amounts. Following a breach in the reactor coolant pressure boundary, reactor coolant is lost at a rate determined by several factors, including break size and RCS pressure. The emergency core cooling systems are relied upon to inject adequate cooling water into the RCS during a LOCA and to circulate the water through the core to provide for core cooling. The ECCS systems must inject cooling water at a rate sufficient to ensure that the calculated changes in core geometry will be such that the core remains amenable to cooling, and that the calculated cladding oxidation and hydrogen generation meet the specified performance criteria. Meeting the requirements of GDC 35 ensures that the ECCS, assuming a single failure, can provide core cooling under accident conditions sufficient to maintain the core in a coolable geometry and to minimize the production of hydrogen due to reaction of water with the fuel cladding. 7. GDC 36 requires that the emergency core cooling systems be designed to allow for periodic inspections of important components to ensure the integrity and capability of the 6.3-11 DRAFT Rev. 3 - April 1996 system. The ECCS system arrangements must be designed such that adequate clearances are available to conduct periodic inspections of important components. Conduct of periodic inspections is necessary to show that important components of the ECCS systems are being maintained within their design basis specifications and that no significant deterioration is occurring in the systems. Meeting the requirements of GDC 36 enhances plant safety by ensuring that important ECCS components can be inspected and will be capable of operating as designed to cool the core under accident conditions. 8. GDC 37 requires that the emergency core cooling systems be designed to allow for comprehensive periodic pressure and functional testing. The ECCS is required to undergo periodic pressure testing to verify the structural and leak-tight integrity of important components.