Document: NUREG-0800
Document ID: dd4f84a9-8976-44c4-b631-d7c0254f4efc
Document Type: srp
Title: PROBABILISTIC RISK ASSESSMENT AND SEVERE ACCIDENT EVALUATION FOR
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1416/ML14161A594.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.0
CFR Part: 
CFR Title: 

Content:
wn PRA may no longer be valid. It is the COL applicant’s responsibility to confirm the assumptions made at the DC stage, and if done properly should capture any significant differences. 2. The staff reviews the applicant’s assumptions related to equipment availability and compares them to TS requirements. Risk-significant equipment should be evaluated with respect to 10 CFR 50.36(c)(2)(ii)(D) to determine whether additional TS requirements are needed. The staff may also review the results of sensitivity studies performed to demonstrate the risk benefit of equipment that is controlled only by voluntary administrative controls (e.g., maintenance rule implementation). 3. The staff reviews the applicant’s implementation of the applicable expeditious actions outlined in NRC Generic Letter (GL) 88-17 (Ref. 14). The staff needs to ensure that the applicant is meeting the expeditious actions consistent with the guidance for meeting the guidelines in GL 88-17 which are described in detail in Enclosures 1 and 2 of the GL. Deviation from GL 88-17 guidance could lead to configurations where cold leg penetrations are permitted to be open in Pressurized Water Reactors (PWRs) without the appropriate steam generator (SG) manway open or when nozzle dams are installed in the wrong order. Such configurations may invalidate PRA results. Staff may review NRC Information Notice (IN) 88-36 (Ref. 15) to understand the risks associated with these configurations. The staff also reviews the licensee’s ability to close containment as described in GL 88-17. 4. The staff reviews the applicant’s implementation of industry guidance for safety during outages provided in NUMARC-91-06 (Ref. 17). In particular, the staff should assure that, if the applicant plans to use freeze seals, the potential for loss-of-coolant accidents due to failed freeze seals has been considered in the PRA. The potential for such accidents is discussed in NRC IN 91-41 (Ref. 28). Reviewers should also confirm the