The Nuclear Regulatory Commission has approved flood protection changes at the three-unit Oconee Nuclear Station. An NRC statement said modifications at the Duke Energy plant near Seneca include new or enhanced flood walls and moving some power lines and equipment to less flood-prone locations.
NRC staff in 2008 requested information from Duke about external flooding, including the potential failure of the Jocassee Dam about 12 miles upstream from the plant. Duke implemented interim compensatory measures, which were inspected by the NRC in 2010. Duke submitted a flood analysis and the NRC issued a confirmatory action letter documenting the company’s commitments.
In 2012, following the Fukushima Dai-ichi accident, the NRC issued another letter requesting more information on flooding. Duke submitted flood hazard re-evaluation reports to the NRC in 2013 and 2015.
In April, Duke informed the NRC that the flooding modifications were complete, and a subsequent inspection led the NRC to determine that the company had satisfied the commitments in the 2010 letter, the statement said.
“The completion of the commitments in the confirmatory action letter gives the NRC confidence that the Oconee plant is adequately protected from external floods, including scenarios involving the failure of the dam,” NRC Region II Administrator Cathy Haney said.
Haney said the years it took to resolve the flooding issues at Oconee were necessary to ensure that the best analyses were used, that information from the accident in Japan was incorporated and that the plant modifications met all requirements.