The same plutonium-laced material that contaminated a Kentucky uranium plant may have passed through as many as nine other sites during the Cold War, sometimes in a concentrated form that would have posed potentially higher risks to workers, senior Energy Department officials said yesterday.

"The days of secrecy and hiding information are over," David Michaels, assistant secretary for environment, safety and health, testified in the first congressional committee hearing on worker safety at the Paducah Gaseous Diffusion Plant.

Michaels, a leader of a two-month investigation of worker safety at Paducah, pledged a thorough review of health risks at all facilities where workers may have handled contaminated, recycled uranium in the 1950s, '60s and '70s. He acknowledged that the government does not yet know what happened to some of the material or whether it posed serious threats.

"We are committed to getting accurate information," Michaels said.

Members of the House Commerce oversight and investigations subcommittee questioned government officials, contractors and workers for nearly six hours about allegations of contamination and cover-up at Paducah, one of three U.S. plants built to produce enriched uranium for nuclear weapons and power plants. Republicans and Democrats expressed outrage at workers' stories of plant conditions, and several pledged to seek compensation and cleanup from those responsible.

"We owe it to the Paducah community to cut through the culture of silence and deceit," said Rep. Thomas J. Bliley Jr. (R-Va.).

Current and former contractors at Paducah insisted they had complied with government regulations on radiation safety.

"To the best of our knowledge the corporation did not mislead workers or DOE as to the state of worker safety, environmental protection or any other matter," said John Jay Hummer, director of environment, safety and health at Lockheed Martin Corp., which ran the plant from 1984 until May.

Workers who presented graphic accounts of contamination and alleged illegal dumping at the plant said they fear that answers are coming too late.

"Many of my good friends are dead, or dying," said Garland "Bud" Jenkins, a worker who had to have his esophagus removed after three decades at the plant. "I always wonder whether plant conditions caused their sicknesses and deaths."

Energy Department officials said the recycled fuel blamed for the contamination was produced at four facilities: the Hanford nuclear reservation in Richland, Wash.; the Savannah River Site in Barnwell, S.C.; the Idaho National Engineering Laboratory in eastern Idaho; and the West Valley Demonstration Project site near Buffalo. A key mission of the department's probe, they said, is tracking where and how the recycled material was used.

Michaels said a preliminary probe shows that the material was handled to varying degrees in at least 13 facilities in 10 locations. The sites include the four production centers; the Paducah plant and its sister uranium plants at Portsmouth, Ohio, and Oak Ridge, Tenn.; the department's uranium foundry at Fernald, Ohio; and two smaller facilities at Weldon Spring, Mo., and Ashtabula, Ohio.

Department records showed unusually high levels of plutonium in some waste shipments from Paducah, suggesting the plant's processes concentrated the cancer-causing metal in ways that could have increased the risk to workers. Containers of ash sent from Paducah to Fernald contained levels of plutonium that were 100 times higher, on average, than the government has reported for recycled uranium. In one case the level was 700 times higher.

CAPTION: Testifying before a House Commerce subcommittee are, from left, David Michaels, assistant energy secretary; Richard D. Green of the Environmental Protection Agency; and Malcolm Knapp of the Nuclear Regulatory Commission.