Document: NUREG-0800
Document ID: 4926757d-c89a-498c-a8cb-918908ab5496
Document Type: srp
Title: of the SAR should provide this information.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350467.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7.3
CFR Part: 
CFR Title: 

Content:
m components are conservatively designed to operate over the range of service conditions. 7. Section 4.6, Channel Independence - Guidance for evaluation of channel independence is provided in IEEE Std 384 as supplemented by RG 1.75. The applicant should confirm that the protection system design precludes the use of componentstthat are common to redundant channels, such as actuation, reset, mode, and test switches; common sensing lines; or any other features which could compromise the independence of redundant channels. Electrical independence shall include the utilization of separate power sources. Physical independence is attained by physical separation and-physical barriers. 8. Section 4.7, Control and Protection System Interaction - Control and pro- tection 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. This section of IEEE Std 279, with regard to isolation devices and multiple failures resulting from a credible single event, is explained by example in the document. The applicant's analysis 7.1-24 Rev. 0 - July 1981 should confirm that the requirements for control and protection system interaction are satisfied. See Section 4.2 above. 9. Section 4.8, Derivation of System Inputs - This requirement is self- explanatory. A protection system'that requires loss of flow protection would normally derive its signal from flow sensors. A design might use an indirect parameter such as a pressure signal or pump speed. However, the applicant should verify that any indirect parameter would be valid for all events. Even a directly measured variable should be reviewed and'its response to postulated events compared with.the credit taken for the parameter in the events for which it provides protection. 10. Section 4.9, Capability for Sensor Checks - The most common method used to. verify the