Document: NUREG-0800
Document ID: f4b8f0c1-9a14-46be-88c9-a6cb74d64dff
Document Type: srp
Title: Rev. 4 — June 1997
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500499.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
t Systems Branch (SPLB) review power source requirements. HICB reviewers should coordinate with these branch requirements to confirm that I&C safety system power sources are adequate.) Transmission of signals between independent channels should be through isolation devices. BTP HICB-11 provides guidance for the application and qualification of isolation devices. Annex G of IEEE Std 7-4.3.2, as discussed in SRP Section 7.1.II, describes an acceptable means for providing communications independence. The review of communications independence should include confirmation that the routing of signals related to safety maintains (1) proper channeling through the communication systems, and (2) proper data isolation between redundant channels. Where data communication exists between different portions of a safety system, the analysis should confirm that a logical or software malfunction in one portion cannot affect the safety functions of the redundant portion(s). If a digital computer system used in a safety system is connected to a digital computer system used in a non-safety system, the review should confirm that a logical or software malfunction of the non-safety system cannot affect the functions of the safety system. 12. Section 5.7 — Capability for Test and Calibration Guidance on periodic testing of the protection system is provided in Reg. Guide 1.22, "Periodic Testing of Protection System Actuation Functions," and in Reg. Guide 1.118, "Periodic Testing of Electric Power and Protection Systems," which endorses IEEE Std 338, "Standard Criteria for the Periodic Surveillance Testing of Nuclear Power Generating Station Safety Systems." The extent of test and calibration capability provided bears heavily on whether the design meets the single-failure criterion. Any failure that is not detectable must be considered concurrently with any random postulated, detectable, single failure. Periodic testing should duplicate, as closely as practical, the overall performance