Document: NUREG-0800
Document ID: 5cb19e99-a561-4571-92e5-2933a6181985
Document Type: srp
Title: CONTAINMENT SPRAY AS A FISSION'PRODUCT CLEANUP SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340761.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.5.2
CFR Part: 
CFR Title: 

Content:
d layout of the spray headers used to distribute the spray flow in the containment space are reviewed. The reviewer verifies that the layout of the headers ensures coverage of essent- ially the entire horizontal cross-section of the containment building with spray, under minimum spray flow conditions. The effect of the post-accident high temperature and pressure conditions in the con- tainment atmosphere on the spray droplet trajectories should be taken into account in determining the area covered by the spray. The layout of the containment building is reviewed to determine if any areas of the containment free space are not sprayed. The mixing rate attributed to natural convection between the sprayed and unsprayed regions of the containment building, provided that adequate flow exists between these regions, is assumed to be two turnovers of the unsprayed region(s) per hour, unless other rates are justified by the applicant. The containment building atmosphere may be consid- ered a single, well-mixed space if the spray covers regions compris- ing at least 90% of the containment building space and if a ventila- tion system is available for adequate mixing of any unsprayed compartmrnts. d. Spray Nozzles The design of the spray nozzles is reviewed to confirm that the spray nozzles are not subject to clogging from debris entering the recircu- lation system through the containment sump screens. 6.5.2-7 Rev. 2 - December 1988 e. Containment Sump Mixing The mixing of the spray water containing any chemical additive and| water without additive (such as spilling ECCS coolant) in the con- tainment sump is reviewed. The areas of the containment building that are exposed to the spray but are without direct drains to the recirculation sump (such as the refueling cavity) are considered. The reviewer confirms that the required sump solution concentrations are achieved within the appropriate time intervals. The pH of the sump solution should be reviewed in regard to iodine