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:
in digital safety systems should be considered whether the systems are to be used in new plants or for upgrades in existing plants. The main difference is that new NPPs predominantly will use digital technology, whereas currently operating plants may introduce digital upgrades in a phased approach. Therefore, Point 4 applies to new plants and to existing plants installing digital equipment in the RTS or ESF. 3.7 Effects of Spurious Actuation Caused by CCF In cases in which a credible postulated spurious actuation(s) caused by a software CCF is not evaluated in design basis accident analyses, an analysis should be performed to determine whether such a postulated spurious actuation results in a plant response that falls outside the values or ranges of values chosen for controlling parameters as reference bounds for design. Further, the analysis should identify whether coping strategies exist for these postulated spurious actuations and consider the adequacy of such strategies. An applicant or licensee should confirm that a coping strategy has been identified to address the effects from credible spurious actuations caused by a CCF that have the potential to place the plant in a configuration that is not bounded by the plant design basis accident analyses. BTP 7-19-18 Revision 7 – August 2016 3.8 Diversity Types NUREG/CR-6303 provides a method for determining uncompensated CCF in safety system designs. Section 2.6, “Diversity,” of NUREG/CR-6303 defines six diversity attributes and 25 related diversity criteria. When NUREG/CR-6303 was published (December 1994,) computer-based digital systems were assumed to comprise the next generation of safety systems. Proposed safety system designs, however, include digital systems that are not computer-based, such as programmable logic devices, field programmable gate arrays, and application-specific integrated circuits. These digital devices and components use software to develop the logic that later resides within the