Document: NUREG-0800
Document ID: f03d2c71-27a1-41fd-9362-1e62c6142e13
Document Type: srp
Title: Containment Systems and Severe Accidents (Tier 1)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070653.pdf
Revision Date: 2023-06
Chapter: 14
Section ID: 14.3.11
CFR Part: 
CFR Title: 

Content:
ents in Tier 1 must be verified by a specific ITAAC entry, unless there are specific reasons why this is not necessary. A. STANDARD ITAAC ENTRIES See Appendix D to this SRP section. B. SYSTEM SPECIFIC ITAAC ENTRIES 1. OPERATIONAL/FUNCTIONAL ASPECTS OF THE SYSTEM The design description captures the system components that are involved in accomplishing the direct safety function. Typically, the system ITAAC specify functional tests, or tests and analyses, to verify the direct safety functions for the various system operating modes. 2. CRITICAL ASSUMPTIONS FROM TRANSIENT AND ACCIDENT ANALYSES The critical assumptions from transient and accident analyses will be verified by ITAAC. Cross-references should be provided in DCD Tier 2 Section 14.3 showing how the key physical parameters from these Tier 2 analyses are captured in Tier 1. These cross- references are also called "Roadmaps". All critical parameters given in the DCD Tier 2 (mainly in chapters 6 and 15) should be identified in the roadmaps. Reviewers should ensure that the critical input parameters are included, as appropriate, in the applicable system ITAAC. The roadmaps and the specific analyses are discussed further in Appendix A to this SRP section. 3. PRA AND SEVERE ACCIDENT INSIGHTS If the results of the PRA indicate that a particular component or function of a system is risk significant, that component or function will be verified by ITAAC. PRA insights will be identified in the DCD Tier 2 and in the staff's SER. The reviewer should verify in the individual system ITAAC that the PRA insights are included in the corresponding system ITAAC as indicated in the DCD Tier 2. Roadmaps for PRA, including shutdown safety analyses, as well as severe accidents, should be included in the appropriate sections of the DCD Tier 2, with specific references to the system ITAAC where the key parameters from these analyses are verified. This is discussed further in Appendix A to this SRP section. DRAFT Rev. 0 - April 1996