Document: NRC Regulatory Guide
Document ID: cfc61809-5745-460f-8a26-13c168659924
Document Type: regulatory_guide
Title: Identification and Characterization of Seismic Sources and Determination of Safe Shutdown Earthquake Ground Motion
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740084.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.165
CFR Part: 
CFR Title: 

Content:
tory Guide 1.12, Revi sion 2.1 D.23 H. Rood et al., "Safety Evaluation Report Related to the Operation of Diablo Canyon Nuclear Pow er Plant, Units I and 2," USNRC, NUREG-0675, Supplement No. 34, June 1991.3 D.24 S.M. Colman, K.L Pierce, and P.W. Birkeland, "Suggested Terminology for Quaternary Dating Methods," Quaternary Research, Volume 288, pp. 314-319, 1987. 1.165-37 1 1 APPENDIX E PROCEDURE FOR THE EVALUATION OF NEW GEOSCIENCES INFORMATION OBTAINED FROM THE SITE-SPECIFIC INVESTIGATIONS E.1 INTRODUCTION This appendix provides methods acceptable to the NRC staff for assessing the impact of new information obtained during site-specific investigations on the data base used for the probabilistic seismic hazard analysis (PSHA). Regulatory Position 4 in this guide describes, ac ceptable PSHAs that were developed by Lawrence Liv ermore National Laboratories (LLNL) and the Electric Power Research Institute (EPRI) to characterize the seismic hazard for nuclear power plants and to develop the Safe Shutdown Earthquake ground motion (SSE). The procedure to determine the SSE outlined in this guide relies primarily on either the LLNL or EPRI PSHA results for the Central and Eastern United States (CEUS). It is necessary to evaluate the geological, seismo logical, and geophysical data obtained from the site specific investigations to demonstrate that these data are consistent with the PSHA data bases of these two methodologies. If new information identified by the site-specific investigations would result in a significant increase in the hazard estimate for a site, and this new information is validated by a strong technical basis, the PSHA may have to be modified to incorporate the new technical information. Using sensitivity studies, it may also be possible to justify a lower hazard estimate with an exceptionally strong technical basis. However, it is expected that large uncertainties in estimating seismic hazard in the CEUS will continue to exist in the future, and