Document: NUREG-0800
Document ID: 915a95d4-8764-4981-952d-5a4327fad655
Document Type: srp
Title: B-4
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:
Draft Revision 6 – August 2015 • Unambiguity - The information provided for the design basis items, taken alone and in combination, should have one and only one interpretation. • Verifiability - The information provided for the design basis items should be stated or provided in such a way as to facilitate the establishment of verification criteria, and the performance of analyses and reviews of the various protection systems. In addition to these characteristics, the following should be noted about the parts of IEEE Std 279-1971, Clause 3. Clause 3(1) of IEEE Std 279-1971 requires in part the identification of conditions that require protective action. This information should be consistent with the analysis provided in Chapter 15 of the SAR. SRP Branch Technical Position (BTP) 7-4 provides specific guidance on the failures and malfunctions that should be considered in identification of design basis events for systems that initiate and control auxiliary feedwater systems. SRP BTP 7-5 provides specific guidance on the reactivity control malfunctions that should be considered in the identification of conditions requiring protective action. The malfunctions assumed should be consistent with the control system failure modes described in Section 7.7 of the SAR and the reactivity control interlock functions described in Section 7.6 of the SAR. Clause 3(2) of IEEE Std 279-1971 requires in part the identification of variables that are monitored in order to provide protective action. The tables in Sections 7.2 and 7.3 of the SAR should provide this information. Clause 3(3) of IEEE Std 279-1971 requires in part the identification of the minimum number and location of sensors for those variables in Clause 3(2) of IEEE Std 279-1971 that have a spatial dependence. The applicant’s or licensee’s analysis should demonstrate that the number and location of sensors are adequate. Subsection 4.2 below discusses the consideration of the single failure criterion in the