Document: NUREG-0800
Document ID: 5b4fe75c-0560-40a2-9e68-366d25bc7ea0
Document Type: srp
Title: and 7.3.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500552.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.2
CFR Part: 
CFR Title: 

Content:
ropagation between redundant channels or systems. For data communication systems that support RTS or ESFAS functions, the analysis should demonstrate that the design is consistent with the assumptions of the D-in-D&D analysis. 3.6 Standardized Safety Analysis Report The Staff's safety determination for design certification of a standardized design is based upon the material in the SAR. To the extent that design detail or other information reviewed in the course of inspections or audits is necessary for the Staff to reach a safety conclusion, that design detail or other information should be available to the Staff. The design detail may be an amendment to or reference in the SAR. 3.7 Tier 1, Tier 2, and Tier 2* Material Material identified as Tier 1 should be that information necessary to ensure that significant features of the certified design application which the Staff is relying upon to make a safety determination are captured in the DCD. Two important factors should be balanced when identifying Tier 1 material: • The safety significance of the design feature or commitment to the Staff's safety determination. • The likelihood that the design feature or commitment will have to be changed in the future. If the reviewer concludes that the details of a particular design feature or commitment are likely to change (the applicant may suggest such candidates), then it is appropriate to limit the amount of detail included in Tier 1. DAC that describe the necessary design acceptance criteria for such features should be provided in lieu of the design detail. Sufficient additional detail, however, should be specified in the SAR Tier 2 material in order for the Staff to make a final safety determination for certification. If the Staff believes these additional Tier 2 details are critical to the safety determination, they should be identified as Tier 2* material in the SER and DCD, thereby requiring prior NRC staff approval if changed. For I&C systems, Tier 1 material