Document: NUREG-0800
Document ID: 80fe9eee-2d6e-4a7e-b7dd-ec23aab2d39f
Document Type: srp
Title: STRATEGIES AND GUIDANCE TO ADDRESS LOSS OF LARGE AREAS OF
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1211/ML121110138.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.4
CFR Part: 
CFR Title: 

Content:
ocumented engineering basis for this assumption. For example, at one site, the licensee assumed that providing 500 gpm flow for the SFP external makeup strategy was the worst case for pumping with the portable pump. The licensee had not done calculations for the other reactor and containment strategies that use the portable pump and may be more limiting. At another site, the licensee did not take into account the 50 psig pressure required to open the Target Rock safety relief valves when calculating flow for the reactor pressure vessel injection strategy. Staff Position The strategies should be described in the application in a manner consistent with guidance in Appendix D of NEI 06-12, Revision 3 and subsequently implemented in the site procedures by the licensee. When the technical bases for strategies and implementing procedures are developed, they should follow engineering practice and proper implementation of that practice. The quality of calculations and analyses performed by applicants in the development of strategies or by licensees during development of implementing procedures should be assured to a reasonable level. However, the level of quality required by 10 CFR Part 50, Appendix B, is not necessary. 9. During system walk downs by NRC inspectors at licensed power reactor sites, the inspectors noted that many licensees had not clearly labeled or tagged plant equipment, such as valves, flanged and threaded connection points, electrical circuit breakers, instruments, and instrument connection points that would be used to implement the strategies. Many licensees relied on existing tags, or if the tags were missing, they relied on the operator to use plant piping and instrumentation drawings. Some of this plant 19.4-22 Revision 0 – May 2013 equipment was not used during normal plant operation, and therefore, operators were not familiar with its location. Staff Position Applicants for COLs or operating licenses should establish measures to ensure that