Document: NUREG-0800
Document ID: 0270f2da-6b35-430d-b965-99a995adea26
Document Type: srp
Title: (Ref. 3).
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350476.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
The review guidance includes references to the guide- lines in regulatory guides and industry codes and standards where applicable. An audit review of the safe shutdown systems should be made to confirm that the systems conform to the guidelines to support the conclusions of conformance to the regulations. The review confirms that the systems required for safe shutdown include the required redundancy; meet the single failure criterion; provide the required capacity and reliability to perform intended safety functions on demand; provide the capability to function during and after design basis events such as earthquakes and anticipated operational occurrences; provide the capability to operate with onsite electric power available (assuming offsite power is not available) and with offsite electric power available (assuming onsite power is not available); and provide the capability to be tested during reactor operation. A major portion of the systems required for safe shutdown are also used as engineered safety features systems, as discussed in SRP Section 7.3. Therefore, the review under this SRP section includes those aspects of ESF systems which are unique to safe shutdown in addition to those systems required for safe shut- down which are not classified as ESF systems. The review is coordinated with RSB and ASB to confirm the acceptability of the redundancy and independence of systems required for safe shutdown. The descriptive information, including the electrical one-line diagrams aid P&IDs (CP and OL) and electrical schematics (OL), should be reviewed to verify that the necessary redundancy is provided. This should include instrumentation channels used to sense vital parameters such as temperature, pressure, water level, etc.; the associated logic and actuated devices; and the motive and control power sources. Conformance with the single failure criterion is verified by review of the same information as for redundancy. The guidance provided by IEEE Std 379 and