CHATTANOOGA, Tenn. (WMOT)  --  The federal Nuclear Regulatory Commission is challenging the Tennessee Valley Authority for what it calls a “chilled work environment” at an East Tennessee nuclear power plant.

The Chattanooga Times Free Press reports TVA officials met Tuesday with the NRC to talk about reports that employees at the Watts Barr power plant in Spring City, Tennessee, don’t feel comfortable taking safety concerns to TVA management.

NASHVILLE, Tenn. (AP/WMOT) — The Sierra Club has filed a lawsuit against the Tennessee Valley Authority over a Freedom of Information Act request for documents.

The environmental organization is trying to learn more about the utility's plan to spend nearly $1 billion to reduce emissions at its coal-fired power plant in Gallatin.

Louise Gorenflo with the Tennessee chapter of the Sierra Club notes that the Gallatin plant is nearly 60 years old. She says the group believes the cost of updating its environmental controls will exceed the value of the plant.

KINGSTON, Tenn. (AP.WMOT) — Four years after a massive coal ash spill in East Tennessee, officials still aren’t sure how to complete the cleanup of the two East Tennessee riverbeds impacted by the disaster.

An estimated 500,000 cubic yards of ash remains at the bottom of the Emory and Clinch rivers following a 2008 spill at the Tennessee Valley Authority's Kingston Fossil Plant.

At a community meeting Tuesday night at Roane County High School, an official with the EPA told residents the options are to leave the submerged ash alone, dredge it up, or cap it.

MURFREESBORO, Tenn (WMOT)  --  On this sixth annual World Malaria Day, a Tennessee historian recalls the little remembered connection between the deadly disease and the Tennessee Valley Authority.

Few Americans remember that malaria was once common in the U.S., or that the TVA played a crucial role in eradicating the mosquito-borne disease.

SPRING CITY, Tenn. (AP) — The Tennessee Valley Authority cost estimate to complete Unit 2 at Watts Bar Nuclear Plant in Spring City, Tenn.,  has been revised upward to $4.5 billion.

The earlier estimate in 2007 had been $2.5 billion.

In a statement released Thursday, the federal utility blamed the increase on poor previous estimates and that reviews to support the initial estimate were not completed.