NRC Continues to Take Action on Flooding Issues

Flooding is one of many natural hazards that U.S. nuclear power plants must withstand in order to safely shut down and protect the public. Well before last year’s accident at Fukushima, the NRC was hard at work ensuring U.S. plants have robust flood protection measures in place, and now we’re focused on having the plants update their flooding analyses.

We’ve devoted significant efforts at two sites – Oconee in South Carolina and Fort Calhoun in Nebraska – to oversee those sites’ work in addressing flooding issues noted by our resident inspectors at the sites. The Fort Calhoun improvements paid off last summer, when the plant safely rode out severe flooding along the Missouri River.

The effort at Oconee, focused on dams upstream of the plant, has been underway for several years. Today, all the information available to the NRC leaves us satisfied that the plant’s owner, Duke, has put appropriate temporary flood-related features in place to ensure the public’s safety in case of flooding at Oconee. We’re monitoring additional work Duke has under way to further enhance Oconee’s permanent flood protection.

The experience at those two plants, however, led us to take a broader look at upstream dams to see if anything else needed to be done. That work was largely completed when Fukushima occurred, and the upstream dam analysis played a role in the NRC requiring every U.S. plant to perform a comprehensive reanalysis of all potential flooding sources. The screening analysis did not evaluate the changes at Oconee or Fort Calhoun; instead it answered the question of whether there were possible improvements at other plants.

The NRC has to keep some of that upstream dam information out of public view for several reasons. For one thing, we must coordinate the use of dam-specific information with our federal partners at the Army Corps of Engineers, the Federal Energy Regulatory Commission and the Department of Homeland Security. Other plant-specific information in the analysis also falls into security categories that are withheld from public release.

Two NRC staffers, one of whom worked on the analysis, have offered their opinions that more information should have been made available. They submitted their concerns to the NRC’s independent Inspector General, which is one method the staff has to formally disagree with an agency decision. While the IG does its work, the NRC can only comment on the analysis currently available on our website.

Scott Burnell
Public Affairs Officer