Energy Secretary Bill Richardson ordered immediate safety improvements at the agency's Paducah, Ky., uranium plant yesterday after an internal investigation turned up dozens of weaknesses in programs designed to shield workers and the public from harmful radiation.

The reforms are intended to correct what regulators called a "lack of discipline, formality and oversight" in the plant's management of radiation risks--deficiencies that officials say left neighbors and many workers in the dark about potential environmental hazards.

Preliminary results from a month-long probe faulted the plant's federal managers and contractors for inadequate radiation monitoring and training, improper storage of radioactive waste and sales of contaminated equipment that may have contained small amounts of radioactive plutonium. At the same time, officials found no evidence that current practices were harming workers or local residents.

"There are radiation risks that should be taken very seriously," said David Michaels, the Department of Energy's assistant secretary for environment, health and safety. "We don't believe workers are in imminent danger, but we believe the program needs to be improved."

The reforms ordered by Richardson include expanded safety training for all workers and the hiring of additional inspectors to monitor adherence to safety regulations. Richardson also called for an independent review of worker safety practices by government contractors at the plant.

Agency officials also announced the retirement of the plant's site manager, Jimmie Hodges, a 30-year Energy employee. A department spokesman said Hodges' decision to leave was personal and not related to the problems at the plant.

Preliminary findings by the team of 23 Energy investigators prompted the declaration of a 24-hour "safety stand down" on Friday, a mostly symbolic act that idled about 400 Energy and contract employees for a day of refresher courses on radiation safety. Yesterday, top department officials described the shutdown as a success.

"We were able to start communicating with workers and to acknowledge the fact that we want to raise the standard at the plant," said Robert Poe, assistant manager for environment and safety in the department's Oak Ridge, Tenn., division, which oversees Paducah.

Richardson ordered the probe at the Paducah plant Aug. 8 after a Washington Post investigation highlighted radioactive contamination at the plant, including worker exposures to plutonium and other radioactive metals. Documents filed in connection with a worker lawsuit accuse the plant's former operators of failing to protect or even warn workers of radioactive hazards that contaminated dozens of buildings and eventually seeped outside the plant's fence.

The findings announced yesterday were part of an initial inquiry into current safety practices at the plant. A parallel probe is examining whether radioactive waste was dumped illegally, as well as claims of worker exposure to harmful levels of plutonium and other radioactive metals before 1990.

The panel's preliminary report concluded that radiation practices at the plant were "considerably improved from the past," and that health risks from the low-enriched uranium now produced at the facility is relatively small. But the report called for further tightening of radiation controls and improved communication about hazards that may exist both inside the plant and in surrounding neighborhoods. Among the findings:

* A plume of contaminated groundwater from the plant is spreading at a rate of about a foot a day and extends over two miles beyond the plant fence.

* Thousands of tons of contaminated scrap metal stored in outdoor junkyards are continuing to leak radioactive metals into two tributaries of the Ohio River. There are currently no plans and no funding for safely disposing of the scrap.

* A number of contaminated areas on both sides of the plant fence had not been fenced off or marked with warning signs.

* Worker training on the hazards of plutonium and other highly radioactive metals had not occurred in at least seven years and had never been formally incorporated into the plant's safety program.

The Energy report strongly criticized the agency for failing to provide proper oversight. The Oak Ridge regional office did not routinely supervise the plant unless asked to do so. The site office of 10 employees focused entirely on clean-up projects and lacked staff "in key technical areas," including worker and environmental protection, the report said.

"We should be getting information out to workers and residents in a better way than we're doing at the present," Michaels said.

CAPTION: The Paducah, Ky., plant, which produces enriched uranium for nuclear weapons and commercial power plants, is suspected of being the source of radioactive contamination.