ADVANCES IN SEISMIC HAZARD ASSESSMENT FOR NUCLEAR FACILITIES IN THE CENTRAL AND EASTERN UNITED STATES

摘要

The United States Nuclear Regulatory Commission (NRC) is currently sponsoring three key projects in the area of probabilistic seismic hazard analysis (PSHA) for the central and eastern United States (CEUS). These projects will provide both new guidance describing the methods to be used for PSHA model development and actual updated seismic hazard assessment input models for the CEUS. These three projects, taken together, will result in an advanced regional PSHA model for critical facilities in the CEUS. They will also provide guidance, a well-documented case study, and a significant number of useful research products, for undertaking PSHA in the US and globally, particularly in low-to-moderate seismicity regions. The first project is the nearly complete NRC Development Project for Practical Procedures for Implementing the Senior Seismic Hazard Analysis Committee (SSHAC) Guidelines and Updating Existing PSHAs. This research program will provide new implementation guidance to complement the original SSHAC guidelines (which are more formally known as NUREG/CR-6372 [1]). The new guidance will be documented in a new NUREG-series report currently in publication [2]. The NUREG provides guidance on the process used to develop Seismic Source Characterization (SSC) and Ground Motion Characterization (GMC) models. The second project, also nearly complete, is the Central and Eastern United States Seismic Source Characterization (CEUS SSC) for Nuclear Facilities Project. The CEUS SSC project will develop an advanced regional SSC model for approximately half of the United States. Lastly, the Next Generation Attenuation Relationship Development for Central and Eastern North America (NGA-East) Project will produce a suite of ground motion prediction equations that will form the basis for a new GMC model for low-to-moderate seismicity regions. Both the CEUS SSC project and the NGA-East project are being conducted as SSHAC Level 3 studies utilizing the original and new guidance.