Federal regulators today slapped the Tennessee Valley Authority with a $145,000 fine for submitting inaccurate information about the reliability of power service to the last new nuclear reactor licensed in America.

The U.S. Nuclear Regulatory Commission said an inspection this summer at the Watts Bar Nuclear Power Plant near Spring City, Tennessee concluded that TVA repeatedly submitted incomplete and inaccurate information to regulators about the adequacy of an off-site electric power system.

NRC announced the penalty today against TVA after the utility officials admitted they inaccurately reported for at least five years from 2010 to 2015 that two common service station transformers could be counted on as qualified sources of off-site power to be used for accident mitigation. An NRC inspection team identified that the transformers lacked enough capacity to provide power to safety-related equipment at Watts Bar in certain accident scenarios.

The NRC judged TVA's failure to be at the lowest level for violations that result in penalties.

TVA spokesman Jim Hopson said the federal utility has since taken corrective actions to resolve the problem and he said the violation did not affect public safety or operations since the off-site power was never required.

The inadequate power service would have been a problem only if plant systems were aligned in an alternative configuration, Hopson said.

"TVA has completed an updated safety analysis and is providing the accurate and complete documentation to the NRC, which confirmed the original issue did not create any negative consequences," Hopson said in a statement after the NRC issued its penalty notice. "The violation did not result in any negative consequences, and TVA has since instituted corrective actions to prevent a recurrence of the violation."

TVA began building Watts Bar in 1973 but didn't complete construction and begin operation of the unit 1 reactor until 1996. The unit 2 reactor was not completed until 2015. 

The second reactor at Watts Bar is the last U.S. commercial nuclear unit to go into power service, although Southern Co. is building two more nuclear reactors at its Plant Vogtle in Georgia.

In 2013, the NRC fined TVA $70,000 for not adequately verifying the quality of safety equipment installed at the Unit 2 reactor at Watts Bar and in 2017 the NRC said TVA had violated a 2009 order by stifling or ignoring some employee comments and concerns at Watts Bar. TVA is still under heightened regulatory review because of NRC concerns about the way whistle blower and other complaints are handled at TVA.

Hopson said TVA is committed to complying with all regulations and safety requirements at Watts Bar and its other operating nuclear facilities at Sequoyah near Soddy-Daisy, Tennessee and Browns Ferry near Athens, Alabama.

"TVA is committed to the safe operation of all its nuclear units, including maintaining the highest level of public safety and having redundant plant safety systems at all times," he said.