No: 14-032 May 9, 2014

CONTACT: Scott Burnell, 301-415-8200 

NRC Prioritizes Detailed Earthquake Risk Analysis

For Central and Eastern U.S. Reactors

The Nuclear Regulatory Commission, following up on work underway when the Fukushima 

accident highlighted the importance of seismic issues in the nuclear arena, has set a priority list for 21 

of 59 nuclear power plant sites in the central and eastern United States to conduct in-depth analyses of 

the plants’ updated earthquake risk.

The agency has reviewed updated earthquake hazard information for the 59 operating reactor 

sites and one unfinished reactor site east of the Rocky Mountains. The sites submitted this information 

in March as part of the NRC’s implementation of lessons learned from the 2011 Fukushima nuclear 

accident. The submittals showed the plants, which have substantial safety margin above their designs’ 

anticipated hazards, are safe for continued operation while more work is done. Should this additional 

analysis indicate more immediate actions are necessary, the NRC will ensure the plants respond 

appropriately.

“We’ve examined this information to see how a plant’s new quake hazard compares to the 

ground movement that the plant’s original design process considered,” said Eric Leeds, director of the 

NRC’s Office of Nuclear Reactor Regulation. “We’re closely following the industry’s response and 

we’re confident the plants are safe to continue operating. If a plant’s new hazard exceeds the original 

design, the plant has to do a detailed analysis to determine any changes in accident risk from a quake.

Plants must also do shorter-term work to see if they should enhance key safety equipment.”

With limited technical expertise available to the industry to complete this effort, the NRC 

prioritized the follow-on work. The priority list is based on several factors that deal with how a site’s 

quake hazard transmits energy at frequencies that can affect a plant’s structures, pipes, pumps and 

related safety systems. A large change between a plant’s original and new hazards at those frequencies 

was a key consideration in determining a plant’s priority. Strong overall ground motions at those 

frequencies also influenced a plant’s priority, as can information from earlier risk evaluations.

The NRC requires these sites to submit their detailed risk analysis by June 30, 2017:

Callaway – Fulton, Mo.; Cook – Bridgman, Mich.; Indian Point – Buchanan, N.Y; North Anna 

– Louisa, Va.; Oconee – Seneca, S.C.; Peach Bottom – Delta, Pa.; Pilgrim – Plymouth, Mass.; 

Robinson – Hartsville, S.C.; Vogtle – Waynesboro, Ga.; Watts Bar – Spring City, Tenn.
Page | 2

The NRC requires these sites to submit their detailed risk analysis by Dec. 31, 2019:

Beaver Valley – Shippingport, Pa.; Browns Ferry – Athens, Ala.; Catawba – York, S.C.; 

Dresden – Morris, Ill.; Fermi – Newport, Mich.; Hatch – Baxley, Ga.; LaSalle – Marseilles, Ill.; Oyster 

Creek – Forked River, N.J.; Palisades – Covert, Mich.; Summer – Jenkinsville, S.C.; Sequoyah –

Soddy-Daisy, Tenn.

These 21 plants have until December 2014 to complete an “expedited approach” review to 

evaluate and reinforce key core cooling equipment to ensure plants could safely shutdown if an 

earthquake in fact were to occur at the higher seismic ground motion. If these reviews show the need to 

enhance that equipment, the work must be complete by December 2016.

The NRC is still deciding whether another 23 sites, including the Bellefonte unfinished reactor 

site in Alabama, require the detailed risk evaluation. The NRC has determined these sites must submit 

the expedited approach assessment by December 2014. If the NRC concludes these sites need the indepth risk analysis they must submit it by Dec. 31, 2020. The remaining 16 central and eastern U.S. 

sites have shown their original design accounts for the new hazard and need no further analysis; three 

of those sites have told the NRC they will provide an expedited approach assessment. The NRC will 

continue to evaluate the plants’ hazard information while risk analyses are underway.

The full list of central and eastern U.S. plants is included in the NRC’s letter to the 60 sites, 

which is available on the agency’s website. The Columbia (Benton County, Wash.), Diablo Canyon 

(Avila Beach, Calif.) and Palo Verde (Wintersburg, Ariz.) sites must submit their new hazard estimates 

in March 2015. The NRC will use the same process to determine which of these sites require additional 

risk analysis. The NRC’s blog has more information on the seismic re-evaluation process.