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
CFR Part: 
CFR Title: 

Content:
capable of functioning under the expected conditions, and is of adequate quality, which may be verified, 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. d. The indications and controls needed to support the manual operator action have the functional characteristics necessary to maintain the plant within the facility operating limits. 3.2.3 Crediting a New Diverse System The applicant may propose a new diverse system (e.g., a diverse actuation system) as a diverse means of accomplishing the same or a different function credited in the D3 assessment or of mitigating spurious operation due to CCF. In this case, the reviewer should determine whether the application demonstrates that (1) the functions performed by this diverse means suffice to maintain plant conditions within specified acceptance criteria for the associated DBE, and (2) sufficient diversity exists between the new system and the proposed DI&C system so BTP 7-19-28 Revision 8 – January 2021 that they are not vulnerable to the same postulated CCF. The reviewer should determine whether the diverse means credited and the digital design of the proposed system are vulnerable to the same CCF. Section 2.6 of NUREG/CR-6303 identifies six diversity attributes and 25 related diversity criteria that the reviewer can use to determine whether the new diverse system is adequate to mitigate the CCF. The new diverse system may be an NSR system if it is of sufficient quality to perform the necessary functions under the associated event conditions. The reviewer should consider whether the new diverse system can function under the event conditions expected and whether it is of adequate quality, which can be verified, 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