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:
SFP, but none had actually calculated or measured the spray flow to determine if 200 gpm had reached the SFP. At one site, the licensee had assumed that a flow rate of 218 gpm from the nozzle would be adequate to assure 200 gpm had reached the SFP, but they had no basis for that judgment. Staff Position The spray flow rate of 200 gpm (400 gpm for dual unit pools) for the local spray strategy is based on SFP designs at licensed Part 50 power reactor facilities. Applicants for COLs or operating licenses should justify applying such a flow rate to their pools and also justify the assumption that the complete pool is covered. 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. Elevated spray strategies should have the same nozzle flow as the local strategy and the spray should be able to reach the intended elevation of the SFP. However, since the spraying may be done through holes in the walls or roof surrounding the SFP, it is not necessary to demonstrate that the entire SFP can be sprayed. 13. NEI 06-12, Revision 3 provides different time requirements for implementation of SFP external spray strategy depending on whether fuel is stored in a dispersed or non-dispersed condition in the pool, but does not define those conditions. Staff Position The NRC staff considers that fuel dispersal exists when permanently discharged fuel is arranged in the defined 1 x 4 pattern, i.e., one recently discharged fuel assembly surrounded by four non-recently discharged assemblies with one on each face and without recently discharged assemblies at the corners. This guidance is consistent with guidance issued to current reactor licensees on February 25, 2005. 14 Paragraph 3.2.1 in NEI 06-12, Revision 3 describes the basic assumptions for developing the extensive damage mitigation guidelines (EDMG). One assumption is that all ac and dc power