Document: NUREG-0800
Document ID: 919b8fa0-8b11-41bd-9694-2c62120b843b
Document Type: srp
Title: Revision 7 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0636/ML063600403.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6
CFR Part: 
CFR Title: 

Content:
tainment Wetwell Sprays The wetwell spray system, including the electrical instrumentation and controls, should meet the standards appropriate to engineered safety features; i.e., quality, redundancy, testability, and other appropriate criteria. The wetwell spray should be automatically actuated 10 minutes following a LOCA signal and an indication of pressurization of the wetwell. In addition, the instrumentation and 6.2.1.1.C-15 Revision 7 - March 2007 control systems provided to actuate the wetwell spray should be actuated by diverse parameters. If the existing wetwell spray system is to be used to improve the bypass capability, the consequences of actuation of the wetwell spray system on ECCS function and long-term pool cooling considerations should be evaluated to show that minimum ECCS and pool cooling requirements are met. b. Transient Bypass Capability Analyses Transient analyses should be provided to establish the capability for a small break. A normal plant shutdown time of 6 hours should be assumed. The results and bases for the analyses should be provided including the following: the pressure history in the drywell and the wetwell; identification and quantification of the static heat sinks and the condensing heat transfer coefficient; spray capacity, efficiency, coverage, start time and temperature history; identification and quantification of heat sources. 2. Leakage Tests and Surveillance Requirements a. High-Pressure Leak Test A single preoperational high-pressure leakage test should be performed on each (Mark II and Mark III) unit. The purpose of this test is to detect leakage in the drywell to suppression chamber vent piping, penetrations, downcomers, vacuum breakers, floor seals, vent seals, and the diaphragm. This test should be performed at approximately the peak drywell to wetwell differential pressure following the high-pressure structural test of the diaphragm. b. Low-Pressure Leak Tests A post-operational low pressure leakage test should be