Document: NUREG-0800
Document ID: b8d2b8f5-432a-4c0a-81ab-20231f7d0f28
Document Type: srp
Title: PROBABILISTIC RISK ASSESSMENT AND SEVERE ACCIDENT EVALUATION FOR
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1508/ML15089A068.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.0
CFR Part: 
CFR Title: 

Content:
he staff reviews the applicant’s implementation of the applicable expeditious actions outlined in NRC Generic Letter (GL) 88-17 (Ref. 15). 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. 17) 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. 10). 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. 18). Reviewers should also confirm the existence of an adequate means to control reactor vessel level and an adequate means to control reactor vessel temperature and pressure during shutdown in Boiling Water Reactors (BWRs). 5. The staff reviews the low power and shutdown Level 2 analysis using methods similar to the at power assessment, considering (1) an estimation of containment capacity considering the capacity of any temporary penetrations, and (2) the feasibility of operators to close containment before adverse environmental conditions prevent closure. The staff reviews the low power and shutdown internal flood and internal fire analysis using methods similar to the at power assessment, considering (1) each