Radiation leak investigated at Three Mile Island

A view of the Three Mile Island nuclear power plant from Goldsboro, Pennsylvania, March 22, 1999.

WASHINGTON (Reuters) - Federal officials are investigating a radiation leak at Three Mile Island, scene of the worst U.S. nuclear power accident, but said on Sunday there was no threat to public health or safety.

Investigators were trying to determine the cause of radiological contamination inside the nuclear facility's containment building on Saturday afternoon.

About 150 people were working in a TMI containment building when the contamination was detected and some were exposed to low levels of radiation, a Nuclear Regulatory Commission spokesman said.

"Based on the information that was provided to us by the company, the level of the dose they received was a small fraction of the NRC's regulatory limit," spokeswoman Diane Screnci said in a telephone interview.

The NRC sent a radiation specialist and a regional manager to the site on Sunday to review the company's assessment. "There was no impact on public health and safety," Screnci said.

Three Mile Island operator, Exelon, said no contamination was found outside the containment building.

One employee was found to have received 16 millirem of exposure and other workers were exposed to lower levels, Exelon said. The annual occupational dose limit for nuclear workers at Exelon nuclear plants is 2,000 millirem, the company said.

The containment building has been shut down since October 26 for refueling and maintenance, Exelon said in a statement.

The plant near the Pennsylvania state capital of Harrisburg created worldwide headlines in 1979 when one of its units partially melted down. The accident made Three Mile Island synonymous with the dangers of nuclear power and helped slow expansion of the U.S. nuclear industry.

Exelon the biggest nuclear power operator in the United States, did not own Three Mile Island at the time.

(Reporting by JoAnne Allen; editing by Doina Chiacu)