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:
ss specific soil and rock characteristics as described in Regulatory Guide 1.132 (Ref. 8). 1.2 The areas of investigations may be expanded beyond those specified above in regions that include ca pable tectonic sources, relatively high seismicity, or complex geology, or in regions that have experienced a large, geologically recent earthquake. 1.3 It should be demonstrated that deformation features discovered during construction, particularly faults, do not have the potential to compromise the safety of the plant. The two-step licensing practice, which required applicants to acquire a Construction Permit (CP), and then during construction apply for an Operating License (OL), has been modified to al low for an alternative procedure. The requirements and procedures applicable to NRC's issuance of com bined licenses for nuclear power facilities are in Sub part C of 10 CFR Part 52. Applying the combined li censing procedure to a site could result in the award of a license prior to the start of construction. During the construction of nuclear power plants licensed in the past two decades, previously unknown faults were often discovered in site excavations. Before issuance of the OL, it was necessary to demonstrate that the; faults in the excavation posed no hazard to the facili ty. Under the combined license procedure, these kinds of features should be mapped and assessed as to 1.165-4 their rupture and ground motion generating potential while the excavations' walls and bases are exposed. Therefore, a commitment should be made, in docu ments (Safety Analysis Reports) supporting the li cense application, to geologically map all excava tions and to notify the NRC staff when excavations are open for inspection. 1.4 Data sufficient to clearly justify all conclu sions should be presented. Because engineering solu tions cannot always be satisfactorily demonstrated for the effects of permanent ground displacement, it is pru dent to avoid a site that has a potential for surface or