Document: NUREG-0800
Document ID: 50ab8154-2a3c-4c0f-8ce4-06ac83096e5c
Document Type: srp
Title: ULTIMATE HEAT SINK
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550048.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.2.5
CFR Part: 
CFR Title: 

Content:
addresses the requirements of GDC 45 regarding the inspection of cooling water systems will be considered acceptable if the design of the UHS permits inservice inspection of safety-related components and equipment. 5. Cooling Water System Testing. Information that addresses the requirements of GDC 46 regarding the testing of cooling water systems will be considered acceptable if the UHS is designed for testing of safety-related systems or components for structural integrity and leak-tightness, operability, performance of active components, and the capability of the system to function as intended under accident conditions. Technical Rationale The technical rationale for application of these acceptance criteria to the areas of review addressed by this SRP section is discussed in the following paragraphs: 1. GDC 2 requires that nuclear power plant SSCs important to safety be designed to withstand the effects of natural phenomena like earthquake, tornado, hurricane, flood, tsunami, and seiche without loss of capability to perform intended safety functions. GDC 2 applies to this SRP section because the reviewer considers UHS capability to withstand natural phenomena. The UHS must be able to provide an adequate supply of cooling water to cool the reactor and its essential support systems under all plausible conditions. RG 1.27 describes methods acceptable to the staff for ensuring UHS capability to withstand the effects of natural phenomena, including earthquakes. GDC 2 requirements provide assurance that SSCs comprised by the plant’s ultimate heat sink have been designed to withstand the most severe natural phenomena likely to occur. 2. GDC 5 requires that SSCs important to safety not be shared by nuclear power units unless such sharing can be shown not to impair their capability to perform intended safety functions. RG 1.27 describes staff positions on UHS design for sharing of SSCs. GDC 5 applies to any multi-unit facility in which a UHS portion is shared by two or