Document: NRC Regulatory Guide
Document ID: aa62c83d-b03d-4406-b6eb-31fc79a0c077
Document Type: regulatory_guide
Title: Development of Floor Design Response Spectra for Seismic Design of Floor-Supported Equipment or Components + HISTORY – HISTORY 05/2019 – Periodic Review of Revision 1 – Reviewed with issues considered for future consideration 03/2015 – Periodic Review of Revision 1 – Revise
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1404/ML14041a433.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.122
CFR Part: 
CFR Title: 

Content:
number ML12333A170; • Interim Staff Guidance DC/COL ISG-020, “Interim Staff Guidance on Implementation of a Probabilistic Risk Assessment-Based Seismic Margin Analysis for New Reactors,” (2010), ADAMS Accession Number ML100491233; • RG 1.200, “An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities”; and • RG 1.208, “A Performance-Based Approach to Define the Site-Specific Earthquake Ground Motion”. 2. What is the impact on internal and external stakeholders of not updating the RG for the known issues, in terms of anticipated numbers of licensing and inspection activities? Determination of floor response spectra based on improved methods is needed for both large light water reactors (LWR) and small modular reactors (SMR). In terms of licensing reviews there are no large power reactor combined license applications anticipated in the near future (next 3 to 5 years). One small modular reactors application is anticipated in the next two years. In addition, NRC received a Design Certification application from Korea Hydro and Nuclear Power (KHNP) for the design for their APR 1400, a large LWR and seismic response spectra will play an important role in the design certification review. The NRC anticipates receiving a topical report for an enhanced seismic certification of the AP1000 in a year or so. An updated version of this RG will be beneficial for new reactor design submittals, the performance of SPRAs for the four new reactors under construction prior to fuel load, and for approximately 40 operating reactor units (NTTF 2.1 Seismic) that will be conducting SPRAs in response to Fukushima requirements. 3. What is an estimate of the level of effort needed to address identified issues in terms of full-time equivalent (FTE) and contract dollars? Revision of the RG will take ~0.5 FTE of staff and contract support to update RG 1.122 with respect to developments in seismology, site response and