Document: NUREG-0800
Document ID: bcc615f1-3f65-4757-994f-88cc8fe800d5
Document Type: srp
Title: should still be met.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070473.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.5.1
CFR Part: 
CFR Title: 

Content:
of concentrations encountered. b. System Operation The time and method of system initiation, including chemical addition, is reviewed to confirm that the acceptance criteria of subsection II are met. Automatic initiation of spray is reviewed under SRP Section 6.2.2. The system operation should be continuous until the fission product removal objectives of the system are met. The reviewer should confirm that all requirements listed in the acceptance criteria, particularly those concerning spray coverage and sump solution pH, are met during the recirculation phase. Switchover from the injection mode to the recirculation mode following initiation to the spray system operation must be automatic to prevent damage to the spray pumps through loss of suction. c. Spray Distribution and Containment Mixing The number and 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 essentially 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 6.5.2-9 DRAFT Rev. 3 - April 1996 containment 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 considered a single, well-mixed space if the spray covers regions comprising at least 90% of the containment building space and if a ventilation system is available for