Document: NUREG-0800
Document ID: 324fd048-3706-4f47-8130-3ca734d7d820
Document Type: srp
Title: B-8
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1515/ML15159A226.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.1
CFR Part: 
CFR Title: 

Content:
d confirm that the protection system design precludes the use of components that are common to redundant channels, such as common switches for actuation, reset, mode, or test; common sensing lines; or any other features that could compromise the independence of redundant channels. Physical independence is attained by physical separation and physical barriers. Electrical independence shall include the utilization of separate power sources. The organization responsible for the review of electrical systems reviews power source requirements. Reviewers in the organization responsible for the review of I&Cs should coordinate with the electrical systems reviewers to confirm that I&C protection system power sources are adequate. Transmission of signals between independent channels should be through isolation devices. SRP BTP 7-11 provides guidance for the application and qualification of isolation devices. 4.7. Control and Protection System Interaction (IEEE Std 279-1971, Clause 4.7) Control and protection system interaction involves more than examining the electrical isolation and interconnection. The functional performance of control systems must be such that a control system cannot prevent proper action of a protection system. Clause 4.7 of IEEE Std 279-1971, with regard to isolation devices and multiple failures resulting from a credible single event, is explained by example in Clause 4.2 of IEEE Std 279-1971. The applicant’s or licensee’s analysis should confirm that the requirements for control and protection system interaction are satisfied.