SAXTON -- Radioactive dirt found at the former Saxton Nuclear Experimental Plant in Bedford County will add about six months' time and $6 million to the cleanup of the site, officials said.

The 168-acre site owned by Penelec operated from 1962 to 1972 as a training facility for nuclear plant workers who would go on to run full-sized plants, including Three Mile Island near Harrisburg.

Cleanup experts believe the dirt, most contaminated with radiation just above levels that normally occur in nature, may have been moved accidentally by workers in the 1970s who were burying fly ash and other waste from an adjoining coal-fired plant.

"How the contamination got there, we don't know," Rodger Grundland, a retired Penn State physicist who is working at an independent inspector at the site, said yesterday. "People may have been a little more careless then about mixing the soils."

Although the Nuclear Regulatory Commission has been decommissioning the site for years, concerted efforts to clean it up began about nine years ago and the price has increased from an initial estimate of $22 million as the cleanup has dragged on.

Spent fuels were shipped to Savannah, Ga., for disposal in 1997, and the plant's reactor and 27-ton steam generator were moved out in 1998. The dome housing the 60-ton reactor was cut apart and sent to an approved nuclear waste site earlier this year.

Just last fall, the cleanup price tag had grown to $63 million and earlier this year that jumped to $70 million, with a projection that the NRC would let Saxton Nuclear out of its operating permit -- which means the site is completely cleaned up -- by year's end.

But now the price tag, borne by parent First Energy Corp., is $76 million and work will last through at least June.

The suspect soil is being removed, tested and those portions found radioactive will be shipped to Duratek Co. in Oak Ridge, Tenn. A small amount of dirt tested at that site had a high level of radiation that required it be sent to Envirocare, a nuclear waste facility in Utah, Grundland said.

The cleanup costs are not being passed on to First Energy customers, the company said.