Document: NUREG-0800
Document ID: eb117be6-f688-40f6-97a8-c91b8e9f8e74
Document Type: srp
Title: CONTAINMENT HEAT REMOVAL SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070457.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.2
CFR Part: 
CFR Title: 

Content:
imum expected temperature of the pumped fluid and with atmospheric pressure in the containment. For clarification, the analyses should be based on the assumption that DRAFT Rev. 5 - April 1996 6.2.2-8 the containment pressure equals the vapor pressure of the sump water. This ensures that credit is not taken for containment pressurization during the transient. a. CSBThe SCSB assuresensures that calculations of the available NPSH are 60 61 based on transient values of the suction head and the friction head. b. The CSBSCSB reviews information provided by the applicant to identify and 62 justify the conservatism applied in determining the water level in the containment and the friction losses in the recirculation system suction piping. For example, the uncertainty in determining the free volume in the lower part of the containment that may be occupied by water, and the quantity of water that may be trapped by the reactor cavity and the refueling canal, should be factored into the calculation of the suction head. 4. The CSBSCSB reviews analyses of the available NPSH for subatmospheric 63 containments for the period prior to termination of the injection phase of containment spray to determine that containment pressure and sump water temperature transients have been conservatively used in the NPSH calculations. a. The CSBSCSB reviews information provided by the applicant to identify and 64 justify the conservatism in the analysis of the containment atmosphere pressure and sump water temperature transients. b. The CSBSCSB also reviews the conservatism used in determining the water 65 level in the containment and the friction losses in the recirculation system piping. 5. The CSBSCSB compares the NPSH requirements for the containment heat removal 66 system pumps to the minimum calculated NPSH available to the pumps to assureensure67 that a positive margin is maintained. The CSBSCSB also reviews the pre-operational 68 test programs, and periodic inservice inspection and test