Central Vermont Public Service Corp. will have to kick in about $3 million more to help with the decommissioning and decontamination of a nuclear power plant in Massachusetts.

CVPS, the state's largest utility, owns a small portion of Yankee Rowe nuclear power plant, which was shut down in 1992 due to aging and cracking problems at what at the time was the smallest and oldest commercial reactor in the country. Decommissioning started in 1993.

According to CVPS spokesman Stephen Costello, CVPS owns only 3.5 percent of the plant, and would be responsible for just under $3 million over the next five years.

"CVPS rates to retail customers are already in place and will not change until the company makes a new rate case filing before the Public Service Board, which at this time we have no specific plan to do," Costello said.

Yankee Rowe, which is owned by a consortium of New England utilities, has filed a rate case with the Federal Energy Regulatory Commission, asking for $80 million more from its owners. The company has already collected and spent about $650 million to dismantle and clean up the reactor.

A spokeswoman for the Vermont Department of Public Service, which acts as the ratepayer's advocate in such cases, said that the state had filed for intervenor status in the case out of concern for the continuing high costs of the decommissioning.

Yankee Rowe, which is located less than a mile from the town of Readsboro, Vt., is completely dismantled, but extensive ground contamination has been uncovered at the site, according to Kelley Smith, spokeswoman for Yankee Atomic, the owner of the plant.

"We've identified additional soil that needs to be excavated and removed," she said.

Smith said the company would have to remove an additional 100 million pounds of contaminated soil and truck it to various waste disposal sites, according to what the contamination is.

Smith said the company had already removed 30 million pounds.

Most of the contamination comes from PCBs, an oil-based hazardous chemical that was used to harden the paint used in the reactor's large spherical containment dome, Smith said. There is also asbestos contamination, she said, and some low-level radiological contamination.

She said the paint chips have been found in Sherman Pond on the Vermont-Massachusetts border.

Of the total of $730 million cleanup, decontamination and demolition work, she said $200 million was for the storage of the plant's high-level radioactive waste, including the design and construction of the storage facility.

The company built a concrete cask storage facility and transferred its old nuclear fuel into the casks for safekeeping until the Department of Energy opens its national nuclear waste facility.

That facility had been planned for Yucca Mountain, Nev., but in the past year has come under increasing attack by Nevada's national politicians, as well as scientists. Earlier this month, legislation was introduced in Congress to abandon Yucca Mountain and have the Department of Energy create or take over individual waste sites at each of the 103 commercial nuclear reactors in the country.

"As we all know, the future of Yucca Mountain is still unfolding," Smith said.

Yankee Atomic has sued the Department of Energy for its failure to construct the high-level waste facility, despite contracts with the nation's nuclear power companies to do so. The trial was held this year, Smith said, and a decision isn't expected until 2006.

Smith said the final cleanup, with the removal of all the contaminated soil, is expected to be completed in August. Cleanup at the site has been suspended for the winter months, she said.