CHATTANOOGA, Tenn. (AP) -- The National Regulatory Commission is increasing oversight of two East Tennessee nuclear plants because of flood-related violations.
The Watts Bar and Sequoyah nuclear plants are operated by the Tennessee Valley Authority. The NRC held a conference with TVA officials in April to discuss the risk significance of preliminary inspection findings in the flood protection area.
The commission determined that the Watts Bar staff would have been unable to implement some of their flood mitigation procedures within the time specified in those procedures.
In the case of the Sequoyah plant, the NRC said TVA did not establish adequate flood protection for the potential failure of upstream dams.
The commission plans follow-up inspections to see what corrections the plants have made.
In March, the NRC ordered U.S. nuclear power plants to upgrade ventilation systems at 31 reactors with designs similar to those that melted down two years ago in Japan.
The filters are required in Japan and much of Europe, but U.S. utilities say they are unnecessary and expensive.
The order requires U.S. operators to upgrade vents to ensure they remain operable even during severe accidents, such as the March 2011 earthquake and tsunami that crippled Japan's Fukushima Dai-ichi nuclear plant. The tsunami sent three of the plant's reactors into meltdown in the world's worst nuclear crisis in a quarter-century.