But lab officials said the radiation doses were quite small and the exposed workers were unharmed.

The accident did not involve the reactor itself, lab officials said.

But lab officials acknowledge that their mismanagement and mixed messages have jeopardized the public trust.

Although many people have called, it has been difficult to get qualified patients, said one lab official who spoke on the condition of anonymity.

When an environmental inspection first found the problems, lab officials said they were taking corrective steps.

But lab officials have also said that former and current landfills on its property were sources of contaminated plumes.

In past statements, lab officials traced the contamination from past disposal practices.

But lab officials say there is a strong reluctance in the Energy Department to shifting gears.

"They brought in a female dancer and watched her perform," said Mona Rowe, a lab official.

"It simply was chaos," said one lab official.