Document: NUREG-0800
Document ID: 13fda301-b942-4542-a493-fc1e4c60019b
Document Type: srp
Title: PROCESS AND EFFLUENT RADIOLOGICAL MONITORING INSTRUMENTATION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070710438.pdf
Revision Date: 2023-06
Chapter: 11
Section ID: 11.5
CFR Part: 
CFR Title: 

Content:
rwise modify the effluent stream. Examples of this function are the termination of exhaust airflow by closure of containment ventilation or purge isolation valves and diversion of building ventilation exhaust streams from an untreated discharge path to an alternative treatment system, such as a standby gas treatment system for a boiling-water reactor (BWR) plant. Depending on plant design and onsite meteorology, such an action may be necessary to mitigate the consequences of a design-basis accident (DBA). The need for such mitigation is determined by calculating the offsite doses that would result from the DBA. In other plant designs, radiological effluent monitors are used to actuate systems to modify or terminate releases for other purposes (e.g., to terminate releases from anticipated operational occurrences to ensure that offsite doses are maintained within the limits specified in the plant technical specifications (TS) and standard radiological effluent controls (SREC)). The design and quality assurance criteria applied to the design, procurement, installation, testing, and operation of radiological effluent monitors installed in light-water-cooled nuclear power reactors should provide assurance that the monitors will perform all of their design functions. If the DBA analysis indicates that the actuation of an engineered safety feature (ESF) system is required to mitigate the consequences of a DBA and a signal from a radiological effluent monitor is necessary to actuate the ESF system, then the monitor should be designed and qualified to the design and quality assurance criteria applicable to the ESF system. Conversely, if an automatically functioning device or system is used to reduce radioactive releases to ensure that offsite doses are maintained within the limits of the plant’s TS and SREC (i.e., not for the purpose of mitigating the consequences of a DBA), then a monitor providing the actuation signal should be designed and qualified to criteria