The Tennessee Valley Authority said its Watts Bar-2 nuclear reactor will be offline until summer.
The 1,200-MW reactor went online in October 2016, but experienced pump problems that prompted a shut down in March. The TVA plant had more service interruptions and employee complaints to the Nuclear Regulatory Commission than any other U.S. nuke last year, according to the Times Free Press.
Unit-1 at Watts Bar was also out of service in March, but for refueling, and the reactor has now returned to service.
Watts Bar-2 is the newest nuclear reactor in the U.S. nuclear fleet. Construction was halted because of low power demand in 1980s when the unit was about half completed. Since then unit 2 was completed at a cost of $4.7 billion.
Watts Bar-2 was the first nuclear plant to be completed in the U.S. in three decades, but safety concerns have mired operations.
In a March 2016 letter to TVA, the NRC warned of a "chilled work environment" after reports that employees were afraid of raising safety concerns. An independent follow-up on that report from last month concluded that safety problems persist, including the lack of clear, objective criteria for evaluating how NRC standards are met.
The consultancy that wrote the follow-up report now says that TVA leaders attempted to manage the results of earlier safety reports to downplay problems. TVA told the Knoxville News Sentinel last month it is taking corrective actions and that "no significant safety issues" exist at Watts Bar.
The utility also emphasized last week that the pump problem prompting this shutdown does not have "any safety consequences to the public or the plant."
Two other new nuclear plants are now in construction — Georgia Power’s Vogtle project and SCANA’s V.C. Summer project. But scheduling delays and cost overruns at those projects have pushed development contractor Westinghouse Electric into bankruptcy, jeopardizing the completion of the reactors.
Just last week Thomas Fanning, CEO of Southern Co., Georgia Power’s corporate parent, said a $3.7 billion guarantee from Toshiba, Westinghouse’s parent, would be necessary to complete the project.