Document: NUREG-0800
Document ID: 96afb1d6-6ce9-41e4-b4ec-1fc7747bc0b2
Document Type: srp
Title: Revision 8 – January 2021
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML2033/ML20339A647.pdf
Revision Date: 2023-05
Chapter: 7
Section ID: 7
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CFR Title: 

Content:
ified, for example, based on the alternative treatment requirements developed for implementation of 10 CFR 50.69, or on the ATWS quality assurance guidance in GL 85-06. Prioritization If a new diverse system is implemented, the reviewer should verify that the signals to actuate components coming from the different systems are appropriately prioritized to maintain the overall defense-in-depth strategy. If the proposed DI&C system and the new diverse system share resources (e.g., priority modules), the reviewer should consider whether the proposed DI&C system has priority in the use of shared resources in regard to its safety and protection functions, so that safety and protection functions are always carried out first. DI&C-ISG-04 provides guidance on prioritization of control and protection systems sharing components. (In some cases, certain components may have more than one safe state; the reviewer should consider whether the priority scheme describes all safe states.) Acceptance Criteria If the following acceptance criteria are met, the reviewer should conclude that the use of a new diverse system is acceptable: a. If NSR equipment is used in the diverse system, the equipment is of sufficient quality to perform the necessary function(s) during the associated event conditions. Sufficient quality can be achieved, for example, through application of the alternative treatment requirements developed for implementation of 10 CFR 50.69 or the ATWS quality assurance guidance set forth in GL 85-06. b. Sufficient diversity exists between the diverse system and the proposed system, so that they are not vulnerable to the same postulated CCF. c. The equipment credited has functional capabilities sufficient to maintain the plant within the acceptance criteria defined in the FSAR or the LAR for the limiting events applicable to the proposed system or component. d. Common resources shared by proposed system(s), other systems, and manual operator actions are controlled by