This site is being furnished to provide you the Central and Eastern United States Seismic Source Characterization (CEUS SSC) for Nuclear Facilities report and its appendices. This website will be updated at the end of April 2012 to provide additional information including the databases used to develop the CEUS SSC model and all documentation required in the Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 assessment process.

CEUS-SSC Project Description

The Central and Eastern United States Seismic Source Characterization for Nuclear Facilities (CEUS SSC) Project was conducted from April 2008 to December 2011 to develop a new, regional seismic source model for use in conducting and reviewing probabilistic seismic hazard analyses (PSHAs) for nuclear facilities in the CEUS. PSHA is a method for assessing site-specific seismic hazard that includes getting the best estimate of ground motions and a transparent quantitative accounting of uncertainty. The results of PSHA are used in seismic design and in calculating seismic risk.

The CEUS SSC Project was funded by the Electric Powered Research Institute (EPRI), the Nuclear Regulatory Commission (NRC) and the Department of Energy (DOE), and it was conducted using the Senior Seismic Hazard Analysis Committee (SSHAC) Study Level 3 assessment process. The SSHAC process ensures consideration of the full range of knowledge and uncertainties of the larger technical community within a robust and transparent framework. The objective of the CEUS SSC project was to develop an up-to-date seismic source characterization model for the CEUS that included::

1. Evaluation of all available data, models and methods that have been proposed by the larger technical community
2. Integration of the evaluated information into a comprehensive model that captures the center, body and range of technically defensible interpretations
3. A complete quantitative and transparent accounting of uncertainties
4. Development and consideration of a new and comprehensive seismological database
5. New approaches to systematically document and evaluate all data considered during model development
6. Engagement of all stakeholders and a robust peer review

BENEFITS: Industry and government share a common need for an updated CEUS SSC Model. The commercial nuclear industry needs the new CEUS SSC Model to support more efficient PSHAs for new and operating reactors. U.S. Nuclear Regulatory Commission (NRC) reviews benefit from industry use of an up-to-date regional PSHA Model that is consistent with current NRC guidance. The U.S. Department of Energy (DOE) needs the model to support PSHAs to meet design and periodic review requirements for its current and future nuclear facilities.

Some of the specific benefits of the model are:

• Consistency: A regional source model allows for consistent input into a PSHA for sites throughout the central and eastern US

• Stability: Proper and thorough characterization of the larger technical community's knowledge and uncertainties­­—coupled with the involvement of the technical community, regulators, and oversight groups—is beneficial to the achieving the goal of maximizing regulatory stability

• Greater Longevity: Representing the center, body, and range of technically-defensible interpretations available at the time of the study (as opposed to attempting to develop a single best interpretation of data) allows the resulting model to better incorporate new information and interpretations.

• Cost and Schedule Savings: for the commercial nuclear industry and DOE to prepare PSHAs

• Advancement of Science: The CEUS SSC Project provides a large amount of new publically available data, models and methods