Document: NUREG-0800
Document ID: 49dad160-99d7-4356-a70a-18bb6f08d141
Document Type: srp
Title: SEISMIC CLASSIFICATION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1422/ML14227A643.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.2.1
CFR Part: 
CFR Title: 

Content:
stic risk assessment (PRA) can be utilized to supplement and enhance the deterministic approach in order to identify these nonsafety-related SSCs that are credited in the PRA. Where industry consensus standards for seismic classification are consistent with NRC regulations, they may be acceptable for licensing purposes. 10. Various approaches, such as the regulatory treatment of nonsafety systems (RTNSS) process, may be considered to designate appropriate seismic requirements, including industry consensus standards and regulatory guidance. The RTNSS process is described in detail in an NRC memorandum from Dennis M. Crutchfield entitled “Consolidation of SECY-94-084 and SE CY-95-132,” dated July 24, 1995 (ADAMS Accession No. ML003708048), which consolidates approved policy positions from the two subject Commission papers and their associated Staff Requirements Memoranda. The RTNSS process is generally applied to passive designs and is considered for advanced reactors on a case by case basis. The designer will impose design requirements and classifications for these SSCs commensurate with their risk significance. For example, in SECY-96-128 and its associated SRM, it was decided that certain RTNSS SSCs for passive advanced light-water reactors (ALWRs) (RTNSS B) need not be safety-related or subject to dynamic qualification, but their anchorage did need to be designed for seismic events and their equipment enclosed in a seismically designed structure. Depending on the particular safety function, other design classifications and criteria may be considered for nonsafety-related SSCs. As part of the 3.2.1-11 Draft Revision 3 – August 2015 PRA, the seismic margins analysis may also be considered in determining which SSC are credited for seismic events and the degree to which they are to be designed for seismic events. IV. EVALUATION FINDINGS The reviewer verifies that the applicant has provided sufficient information and that the review and calculations (if