United States Nuclear Regulatory Commission - Protecting People and the Environment

Evaluations of NRC Seismic-Structural Regulations and Regulatory Guidance, and Simulation-Evaluation Tools for Applicability to Small Modular Reactors (SMRs) (NUREG/CR-7193)

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Publication Information

Manuscript Completed: February 2013
Date Published: March 2015

Prepared by:
Robert J. Budnitz, Dismitrios Konstantinidis*

Earth Sciences Division
Lawrence Berkeley National Laboratory
University of California, Berkeley, CA 94720

Zhiguang Zhou**

Pacific Earthquake Engineering Research Center
University of California, Berkeley, CA 94720

*Now at Department of Civil Engineering
McMaster University, Hamilton, Ontario, ON L8S 4L7, Canada

**Now at College of Civil Engineering
Tongji University, Shanghai, 200092 China

Thomas J. Herrity, NRC Technical Monitor

Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington DC 20555-0001

Availability Notice


This report consists of two different evaluations sponsored by the U.S. Nuclear Regulatory Commission (NRC) and performed by Lawrence Berkeley National Laboratory. The first evaluation covers NRC regulatory guidance in the seismic-structural area. The second evaluation covers several seismic-structural simulation tools used in NRC regulatory applications. Each evaluation examines the appropriateness of the regulatory guidance (provided in regulations, guidance, review plans, etc.), or of the simulation tool for its applicability to small modular reactors (SMRs). The objective of each evaluation is to address the following: The bulk of NRC’s regulatory work on nuclear power reactor safety has been concentrated for decades on large light-water reactors (LWRs). While the regulations are technology neutral, many of the agency’s positions have evolved with large LWRs as the sole technology of interest. Also, the technical analysis tools (computer codes) used in reactor safety guidance, either by the NRC itself or by its licensees and applicants, including structural analysis tools as well as those used to determine ground motion and to analyze soil structure interaction (SSI) effects, have been used to analyze large LWRs. This report examined whether regulatory guidance, or the analysis tools currently used in the seismic-structural area, could benefit from modification to better address small modular reactors (SMRs). It concluded that most documents reviewed do not need any modifications and are acceptable as currently written.

Recommendations for modifications are presented as appropriate. Also, it concluded that the software packages reviewed should yield acceptable results when applied to an SMR. The report can be used to inform the NRC’s efforts to update regulatory guidance in support of licensing reviews of SMR applications.

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