The Associated Press

COLUMBUS - A lawsuit accuses the operators of the Portsmouth Gaseous Diffusion Plant in Piketon of altering the records of workers' exposure to radiation to qualify for federal government safety bonuses.

The lawsuit was filed in 2000 in U.S. District Court under the false-claim act, but a judge unsealed it just last week, the Columbus Dispatch reported.

Plant security guard Jeff Walburn contends in the lawsuit that Lockheed Martin, Lockheed Martin Utility Services and U.S. Enrichment Corp. used false and unreliable exposure readings to receive incentive payments for operating a safe work environment.

The false-claim act allows a civilian to sue on behalf of the federal government when it overpays a supplier because of alleged fraud.

USEC and Lockheed Martin both declined to comment.

If Mr. Walburn wins, he could receive a cut of damages awarded to the U.S government.

Mr. Walburn's attorney, Steve Edwards, said he has depositions from two employees who said they altered 400 to 600 records per year.

"We have evidence in Jeff's case that his records were changed twice," Mr. Edwards said.

The plant helped produce weapons-grade uranium and handled plutonium during the Cold War.

The plant was closed last year but operations to decontaminate it are continuing.

Congress two years ago approved payments to workers exposed to radiation at the plant who have been diagnosed with cancer.

Piketon is 100 miles east of Cincinnati.