Document: NUREG-0800
Document ID: fa6f6a6f-6b58-4b9d-bff6-146879b1bdbf
Document Type: srp
Title: REACTOR COOLANT PRESSURE BOUNDARY LEAKAGE DETECTION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340605.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.2.5
CFR Part: 
CFR Title: 

Content:
em leakage in the affected system and provides adequate monitoring capability so the limits assumed in the accident analyses are not exceeded. Intersystem leak detection methods include radioactivity, pressure, temperature, flow and pressure relief valve actuation indications, and the water inven- tory balance method. Table I shows some of the systems that require intersystem leakage monitoring. 4. The reviewer verifies that the leakage detection systems will remain functional for all seismic events not requiring a shut down and that the airborne particulate radioactivity monitoring system (APM) remains functional when subjected to the safe shutdown earthquake (SSE). 5. The reviewer verifies that all of the leakage detection systems have readouts in the control room and are provided with alarms. Direct reading systems, such as sumps, will normally indicate in gpm. The indirect reading systems, such as the APM, will indicate in counts per minute. The reviewer determines that control room operators will have a chart or graph that permits rapid conversion of count rate into gpm, that conversion procedures take into account the isotope being monitored and the activity of the primary coolant, and that the plant will maintain a running record of background leakage, so that its effect may be factored out from any sudden increases in leak indication, which may be "unidentified" leakage and require prompt action. If monitoring is computerized, backup procedures should be available to the operator. 5.2.5-3 Rev. 1 - July 1981 6. The reviewer verifies that the sensitivity and response of the detection system is acceptable over the entire range of expected plant operating conditions of which it is monitoring. The reviewer ve.ri- fies that the instrumentation and methodology used to determine leak rates are adequate. 7. The reviewer determines that the radiation monitoring systems have a radioactive source built into the system (the SAR refers to this feature as a "check source")