Document: NUREG-0800
Document ID: 3571c656-1693-466b-a77d-6c05b7eed41e
Document Type: srp
Title: REACTOR SYSTEMS - INSPECTIONS, TESTS, ANALYSES, AND
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070660623.pdf
Revision Date: 2023-06
Chapter: 14
Section ID: 14.3.4
CFR Part: 
CFR Title: 

Content:
of 10 CFR 52.80(a), as it relates to ITAAC (for combined licenses) provides reasonable assurance that the SSCs in this area of review have been constructed and will be operated in conformity with the combined license, the provisions of the Atomic Energy Act, and the NRC’s regulations. 3. Tier 1 should be reviewed for treatment of design information proportional to the safety significance of the SSC for that system. SSCs involving the reactor and core-cooling systems, such as the overpressure protection system, may be classified or judged to be important to safety and thus should be included in Tier 1. 4. NRC rules and regulations, generic correspondence, PRA insights, and operating experiences provide important sources for identifying significant design and features for inclusion in Tier 1. 5. Those active systems classified as non-safety systems are potentially the first line of defense to reduce challenges to the passive systems in the event of transients or plant upsets. While the passive systems are designed to perform their safety functions independently of operator action or off-site support for 72 hours after an event, these non-safety or active systems are capable of supplying water to the passive systems or directly performing core and containment heat removal functions and, therefore, should be considered as Tier 1. RTNSS evaluations provide a systematic determination of non-safety systems’ impact that should be included in Tier 1. 6. The Commission provides applicable guidance for selected policy and technical issues related to a particular design that should be used by the reviewer. Examples of such guidance are contained in SECY-93-087. 7. Where a COL applicant references a certified standard design, the ITAAC, as contained in the standard certified design, must apply to those portions of the design that are covered by the design certification rule, as contained in the appendices to 10 CFR 52 (e.g., Appendix A for the ABWR, Appendix B for the