Document: NUREG-0800
Document ID: 7b4fb774-803a-419c-bdec-3b31c351a3fe
Document Type: srp
Title: REACTOR COOLANT PRESSURE BOUNDARY LEAKAGE DETECTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0706/ML070610277.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.2.5
CFR Part: 
CFR Title: 

Content:
irborne particulate radioactivity monitoring system remains functional when subjected to a safe shutdown earthquake. 5. The reviewer verifies whether all leakage detection systems have readouts in the control room and alarms. Direct reading systems, like sumps, normally indicate liters per minute (L/m) (gpm). Indirect reading systems, like the airborne particulate radioactivity monitoring system, indicate counts per minute. The reviewer determines whether control room operators have a chart or graph that permits rapid conversion of count rate into L/m (gpm), whether conversion procedures account for the isotope monitored and the activity of the primary coolant, and whether the plant maintains a running record of background leakage to factor its effect out from any sudden increases in leak indication, which may be "unidentified" leakage and to accordingly initiate prompt action. If monitoring is computerized, backup procedures should be available to the operator. 6. The reviewer verifies whether the detection system sensitivity and response are acceptable over the entire range of expected plant operating conditions monitored. The reviewer verifies whether the instrumentation and methodology for determining leak rates are adequate. 7. The reviewer determines whether the radiation monitoring systems have built-in radioactive sources (the FSAR refers to this feature as a "check source") for operability testing and calibration during operation. The reviewer determines whether there are provisions for testing and calibrating the sump level detection system, a method for calibrating the air cooler condensate flow system wherever radiation monitors are used, and a method for calibrating them to RCPB leakage. The frequency of testing and calibration should be justified. The reviewer also determines whether periodic testing of the floor drainage system checks for blockage and ensures operability. For review of a DC application, the reviewer should follow the above procedures