Document: NUREG-0800
Document ID: 757b676a-0f71-4094-8677-ca3a50743281
Document Type: srp
Title: Revision 7 – August 2016
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1601/ML16019A344.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
stem,) even if the annunciation did not occur on initial test or startup. Failures of the automated protection system stemming from a software CCF can cause spurious actuations. The plant design basis addresses the effects of certain software CCF-caused spurious actuations. The overall defense in depth strategy of a plant should prevent or mitigate the effects of credible spurious actuations caused by a software CCF that have the potential to place a plant in a configuration that is not bounded by the plant’s design basis. The effects of some credible postulated spurious actuations caused by a software CCF in the automated protection system may not be evaluated in design basis accident analyses. In these cases, an analysis should be performed to determine whether these postulated spurious actuations could result in a plant response that results in conditions that do not fall within those established as bounding for plant design. Further, the analysis should identify whether adequate coping strategies, whether for prevention or mitigation, exist for these postulated spurious actuations (e.g., emergency, normal, and diverse equipment and systems, controls, displays, procedures and the reactor operations team). If existing coping strategies are not effective for responding to the credible postulated spurious actuations that result in plant conditions falling outside those established as bounding for plant design, the licensee should develop additional coping strategies. 1.9 Design Attributes to Eliminate Consideration of CCF Many system design and testing attributes, procedures, and practices can contribute to significantly reducing the probability of CCF. However, there are two design attributes, either of which is sufficient to eliminate consideration of software based or software logic based CCF: Diversity or Testability (1) Diversity – If sufficient diversity exists in the protection system, then the potential for CCF within the channels can be considered to be