Document: NUREG-0800
Document ID: 74415b71-98a0-4109-9ba7-8a72a89a3d18
Document Type: srp
Title: ULTIMATE HEAT SINK
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070520.pdf
Revision Date: 2023-06
Chapter: 9
Section ID: 9.2.5
CFR Part: 
CFR Title: 

Content:
n Criterion 45 (GDC 45), as related to the design provisions to permit 32 inservice inspection of safety-related components and equipment. For ultimate heat sink designs using dams, slopes, canals, or other water-control structures, acceptance for portions of the UHS is based on meeting the guidance of Regulatory Guide 1.127, "Inspection of Water-Control Structures Associated with Nuclear Power Plants."33 5. General Design Criterion 46 (GDC 46), as related to the design provisions to permit 34 operation functional testing of safety-related systems or components. Technical Rationale The technical rationale for application of these acceptance criteria to reviewing the ultimate heat sink is discussed in the following paragraphs:35 1. Compliance with GDC 2 requires that nuclear power plant structures, systems, and components important to safety be designed to withstand the effects of natural phenomena such as earthquake, tornado, hurricane, flood, tsunami, and seiche without loss of capability to perform their intended safety functions. GDC 2 is applicable to this SRP section because the reviewer considers the ultimate heat sink's capability to withstand natural phenomena. The ultimate heat sink must be able to provide an adequate supply of cooling water to cool the reactor and its essential support systems under all credible conditions. Regulatory Guides 1.27 and 1.29 describe methods acceptable to the staff for ensuring the capability of the ultimate heat sink to withstand the effects of natural phenomena, including earthquakes. Meeting the requirements of GDC 2 provides assurance that structures, systems, and components comprised by the plant's ultimate heat sink have been designed to withstand the most severe natural phenomena likely to occur.36 DRAFT Rev. 3 - April 1996 9.2.5-6 2. Compliance with GDC 5 requires that structures, systems, and components important to safety shall not be shared by nuclear power units unless it can be shown that such sharing will not