Officials at Browns Ferry Nuclear Plant, looking to save TVA ratepayers money, want to study the use of reprocessed weapons-grade plutonium as fuel in its Limestone County reactors.

The Tennessee Valley Authority is the only power company considering the plutonium-based mixed-oxide fuel, or MOX. TVA entered into an agreement with the Energy Department to study the feasibility of using the fuel at Browns Ferry and at Sequoyah Nuclear Plant, near Soddy-Daisy, Tenn.

“TVA has made no decision to use mixed-oxide fuel at any of our reactors,” TVA spokesman Ray Golden said last week.

TVA would only agree to use the material, Golden said, if MOX is “environmentally and operationally safe, licensed by the Nuclear Regulatory Commission and economically beneficial to TVA’s customers.”

A public hearing will be held Thursday on the plant’s proposal, starting at 5:30 p.m. at the Aerospace Building at Calhoun Community College. The formal hearing, which includes a presentation by the Energy Department, will begin at 6:30.

A recent U.S. Department of Energy study concluded that, with safeguards, MOX would not be more dangerous to the public than conventional fuel.

Some disagree.

The Energy Department has spent billions on an unfinished facility to convert plutonium to MOX in South Carolina, even though no nuclear plants have committed to using the fuel.

The conversion process makes MOX far more expensive to produce than the low-enriched uranium fuel Browns Ferry was designed to use. It could nonetheless benefit TVA because of federal incentives if TVA agrees to use MOX.

Golden said TVA has not negotiated an incentive contract, so the extent of the economic benefit to TVA ratepayers is unknown.

Edwin Lyman, a senior staff scientist with the Union of Concerned Scientists in Washington, D.C., said MOX would be dangerous at any plant, and especially at Browns Ferry.

“MOX fuel decreases the safety of boiling water reactors,” the type used at Browns Ferry, Lyman said. “It makes the reactors harder to control. MOX fuel, in an accident, could behave worse than uranium fuel.”

The Browns Ferry reactors are the same type used at the Fukushima Daiichi Nuclear Power Station in Japan, which suffered meltdowns last year after an earthquake-triggered tsunami. A 12-mile evacuation zone remains in effect around the Japan reactors, one of which used a form of MOX fuel. TVA has implemented several modifications to reduce the risk of a similar incident at Browns Ferry, which is 11 miles northwest of downtown Decatur.

Because MOX is a mixture of two elements — uranium and plutonium — it does not blend evenly, Lyman said.

“You tend to get clusters of plutonium forming hot spots,” Lyman said. “That increases the risk of various types of accidents. It’s more dangerous.”

Lyman said the radiation released in the event of an accident would be more toxic because of the plutonium.

He disputes an Energy Department study indicating MOX fuel would be about as safe as conventional uranium fuel.

The idea behind using MOX for fuel was to prevent nuclear proliferation, Lyman said. Two decades ago, Russia had a weak central government, and U.S. officials feared its plutonium stockpiles were vulnerable to theft by rogue states or terrorists. In treaties, the two countries agreed to reduce their surplus weapons-grade nuclear material by recycling it into forms that were less attractive to terrorists.

The preferred U.S. method for reducing its stockpile was to convert the plutonium into MOX for use in reactors.

“MOX is a cure that’s worse than the disease,” said Lyman, because transport and storage at facilities such as Browns Ferry make it more accessible to terrorists.

Referencing a Nuclear Regulatory Commission report issued Thursday, Lyman said recent problems at Browns Ferry make it especially unsuitable for MOX.

“All three Browns Ferry units are in the category of degraded performance,” Lyman said. “Unit 1 is in the worst category. It’s the only one in the country in that category.”

Public hearing

What: The Energy Department will hold a public hearing on the use of plutonium-based mixed-oxide fuel at Browns Ferry Nuclear Plant.

When: Thursday. An open house will begin at 5:30 p.m., followed by a presentation at 6:30.

Where: Aerospace Building at Calhoun Community College, 6250 U.S. 31 North in Tanner.