Document: NRC Regulatory Guide
Document ID: 4d46a966-d280-43da-9b03-8b0abe7b29ce
Document Type: regulatory_guide
Title: Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2120/ML21204A065.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.183
CFR Part: 
CFR Title: 

Content:
of record (e.g., ASME B31.1, “Power Piping”) and if the peak spectral acceleration of the ground motion response spectrum based on the licensee’s most recent site-specific probabilistic seismic hazard is less than 0.4g, the justification should include (1) discussion of seismic capacity and margin present in the relevant SSCs, including the condenser, based on their design code(s) of record, (2) insights from plant-specific seismic assessment performed as part of the Individual Plant Examination for External Events for relevant SSCs, (3) a walkdown of a sample of the relevant SSCs, including the condenser, performed by knowledgeable licensee staff to verify that they have been constructed as designed, and (4) confirmatory calculations for a sample of piping supports to verify that they provide acceptable flexibility at terminal ends of piping and major branch connections. The extent of the selected samples should be justified based on the plant-specific seismic hazard and quality assurance applied to design and fabrication. Details of the walkdown(s), including qualification of licensee staff performing them, should be retained in archival documentation. (3) If the SSCs in the alternate pathway have not been subjected to dynamic seismic analysis to a code of record (e.g., ASME B31.1, “Power Piping”) and if the peak spectral Note: The revised seismic analysis of the alternative drain pathway presented below is intended to be used with the aerosol deposition models in Regulatory Position A-5.6. Note: The revised seismic analysis of the alternative drain pathway presented below is intended to be used with the aerosol deposition models in Regulatory Position A-5.6. DG-1389, Appendix A, Page A-9 acceleration of the ground motion response spectrum based on the licensee’s most recent site-specific probabilistic seismic hazard is greater than 0.4g, the justification should include (1) discussion of seismic capacity and margin present in relevant SSCs, including