The Tennessee Valley Authority will face a series of meetings with federal regulators over updated flood projections that now exceed the design limits at two of its nuclear plants.
Updates to flood modeling conducted as part of TVA's Bellefonte completion project resulted in a probable maximum flood level that exceeds the licensing assumptions at the Watts Bar plant by 4 feet and at the Sequoyah plant by 2.5 feet. A public meeting to address the discrepancy took place Monday, the Chattanooga Times Free Press reported, when officials from the Nuclear Regulatory Commission questioned TVA executives about interim flood mitigation measures at the plants. TVA increased the height of dams relevant to the plants by several feet using baskets filled with sand and crushed rock, but NRC officials noted the barriers include large gaps where they intersect roads. A TVA vice president responded that the utility's emergency planning would allow for crews to complete the barriers if extreme flood conditions appeared in the forecast. He also said the barriers could withstand the impact from a loose barge.
The NRC and TVA will continue their public discussion of flood mitigation at another meeting on Dec. 13.