NEW SEISMIC MODEL WILL REFINE HAZARD ANALYSIS

AT U.S. NUCLEAR PLANTS

The Electric Power Research Institute (EPRI), the U.S. Department of Energy (DOE), 

and the U.S. Nuclear Regulatory Commission (NRC) released a new seismic study today that 

will help U.S. nuclear facilities in the central and eastern United States reassess seismic hazards. 

The Central and Eastern United States Seismic Source Characterization for Nuclear Facilities

model and report is the culmination of a 4-year effort among the participating organizations and 

replaces previous seismic source models used by industry and government since the late 1980s.

The NRC is requesting U.S. nuclear power plants to re-evaluate seismic hazards using 

this information as well as other guidance. This work is part of the agency’s implementation of 

lessons learned from events at the Fukushima Daiichi nuclear power plant following the March 

2011 earthquake and tsunami in Japan. The new seismic model will be used by nuclear power 

plants in the central and eastern United States for these re-evaluations, in addition to being used 

for licensing of new nuclear facilities.

The project gathered and analyzed an expanded data set – including historical earthquake 

and geological data for the entire study region from 1568 through 2008 – using a rigorous, peerreviewed assessment process. National and international experts from industry, government, 

academia, and various research organizations were engaged to develop the model.

The model can be used to calculate the likelihood of various levels of earthquake-caused 

ground motions. Calculations with the new model are expected to result in a higher likelihood of 

a given ground motion compared to calculations done using previous models. These calculations, 

however, are not equivalent to a nuclear power plant’s overall risk. Plant operators must combine 

the information from the new model with a plant’s design and safety features to determine sitespecific risks.

As part of the project, the new seismic model was compared to previous models by 

calculating seismic hazards at seven test sites. The sample calculations indicate that the largest 

predicted ground motions could occur in the vicinity of repeated large magnitude earthquake 

sources, such as New Madrid, Mo., and Charleston, S.C.

The report and model are available at http://www.ceus-ssc.com. 

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NRC NEWS

U.S. NUCLEAR REGULATORY COMMISSION

Office of Public Affairs Telephone: 301/415-8200

Washington, D.C. 20555-0001

E-mail: opa.resource@nrc.gov Site: www.nrc.gov

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No. 12-010 January 31, 2012
The Electric Power Research Institute, Inc. conducts research and development relating 

to the generation, delivery and use of electricity for the benefit of the public. An independent, 

nonprofit organization, EPRI brings together its scientists and engineers as well as experts from 

academia and industry to help address challenges in electricity, including reliability, efficiency, 

health, safety and the environment. EPRI's members represent more than 90 percent of the 

electricity generated and delivered in the United States, and international participation extends to 

40 countries. EPRI's principal offices and laboratories are located in Palo Alto, Calif.; Charlotte, 

N.C.; Knoxville, Tenn.; and Lenox, Mass.

The mission of the U.S. Department of Energy is to ensure America’s security and 

prosperity by addressing its energy, environmental and nuclear challenges through 

transformative science and technology solutions.

The U.S. Nuclear Regulatory Commission was created as an independent agency by 

Congress in 1974 to ensure the safe use of radioactive materials for beneficial civilian purposes 

while protecting people and the environment. The NRC regulates commercial nuclear power 

plants and other uses of nuclear materials, such as in nuclear medicine, through licensing, 

inspection and enforcement of its requirements.

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