The Tennessee Valley Authority says environmental concerns and safety changes in the wake of Japan's nuclear crisis are delaying construction and operation of its $2.5 billion Watts Bar Unit 2 nuclear reactor in Tennessee.

TVA had hoped to permit, build and begin operating the reactor by the end of next year but now says the facility is 86 percent complete and may not be operational until 2013. The reactor is located about 50 miles northeast of Chattanooga, Tenn.

"Obviously we're disappointed in the slight delay, but the important thing for us is to have high safety [standards] and quality," said Ray Golden, a TVA spokesman.

A coalition of environmental groups -- including the Southern Alliance for Clear Energy and Sierra Club -- has raised concerns with the Nuclear Regulatory Commission that warm water discharges from the nuclear unit could endanger aquatic life in the Tennessee River. NRC's Atomic Safety and Licensing Board, which is reviewing TVA's permit application, has agreed to hear the groups' concerns, and Golden said the process will "likely take longer than we initially anticipated."

TVA believes the warm water discharges will have minimal environmental effects on the water body, Golden added.

Costs and construction of the Watts Bar reactor will also be affected by safety changes TVA is making in the aftermath of the March 11 earthquake and tsunami that struck Japan's Fukushima Daiichi nuclear plant, triggering hydrogen explosions, radioactive leaks and multiple evacuations.

TVA is retooling several safety features at its plants in Tennessee and Alabama, including the Watts Bar Unit 2 reactor.

Near-term changes include buying more gasoline-powered electric generators, diesel-powered water pumps and satellite phones, as well as ramping up training of personnel, Golden said. The company is also considering intermediate and long-term changes and may possibly bring in a fifth diesel generator to Watts Bar, remove older spent fuel from storage pools and harden pipes that transport water to the spent fool pools, Golden said.

Such changes could result in "millions of dollars" in expenditures for TVA, Golden said, though he added that exact costs are still unknown.

NRC's near-term task force also released its recommended safety changes last month, which TVA said it will digest and calculate into changes that need to be made and new costs (ClimateWire, July 13).

The delay comes amid a reshuffling of top brass within the federal agency. TVA said yesterday it will provide a two-month transition in the leadership for its nuclear generation development and construction group.

Ashok Bhatnagar, the group's current senior vice president, is retiring on Oct. 1. TVA's Chief Operating Officer Bill McCollum has named Mike Skaggs, currently site vice president at the Sequoyah Nuclear Plant, to replace Bhatnagar.

John Carlin, who was site vice president at Constellation's R.E. Ginna Nuclear Power Plant, will now be the new site vice president at the Sequoyah nuclear plant, TVA said.