PORTLAND (AP) – The site of the former Maine Yankee atomic power plant holds 600 metric tons of nuclear waste sealed in 64 concrete and steel casks that are designed to last for decades.

But now there are concerns that more of the highly radioactive waste could be diverted to the Wiscasset site if legislation in Washington passes.

The Bush administration proposal seeks to reprocess waste so that less is stored permanently at a proposed dump at Yucca Mountain in Nevada, the designated federal storage site that was supposed to open in 1998.

Legislation that awaits a Senate vote also envisions temporary storage at sites across the country because Yucca Mountain is years behind schedule to open.

Some critics don’t want a program they say would divert resources and support for Yucca Mountain, which is limited by law to accepting 70,000 metric tons of waste.

Others, including Maine lawmakers, municipal officials and advocacy groups, are concerned that the Maine Yankee site could become a dumping site for New England’s waste.

“I think it could lead to a situation where Maine might be stuck holding the bag here,” said Edwin Lyman, a senior scientist at the Union of Concerned Scientists.

Lyman’s group is part of a coalition effort that includes Physicians for Social Responsibility and the Sierra Club that is urging Maine Sens. Olympia Snowe and Susan Collins to oppose the program in a spending bill.

While neither of the Republican senators has said how she will vote on the bill awaiting action in the Senate, each opposes storing nuclear waste at Maine Yankee for the 25 years that the legislation allows.

“Having led the charge to defeat the potential placement of a second national nuclear repository in Maine in the 1980s, I will unequivocally oppose any legislation that could open up the state of Maine to either a nuclear fuel reprocessing site or an interim storage facility,” Snowe said.

Collins said she would “vigorously oppose any effort to store outside waste in Maine.”

“I will also continue to push the federal government to ensure that the waste that we have currently is removed from Maine in a safe and secure manner,” she added.

With completion of the Yucca Mountain storage site delayed, a provision in the federal legislation allows the U.S. energy secretary to take title to closed plants such as Maine Yankee and take responsibility for the storage of high-level nuclear waste until it can be moved.

Another provision calls on the energy secretary to designate a consolidation site for waste within any state with a reactor for 25 years.

“The state has no power to stop this,” said Lyman of the Union of Concerned Scientists. “Maine, in particular, might be seen as a good candidate for this by proponents as a New England regional facility.”

U.S. Rep Tom Allen, D-Maine, said he too is concerned about the provision.

“It’ll adversely affect Yucca Mountain and that will mean that we’ll have nuclear waste in Maine for years, if not decades, longer,” he said.

Wiscasset Town Manager Andrew Gilmore said the town has no interest in increasing storage at Maine Yankee or hosting a reprocessing center, adding, “We would adamantly oppose it.”

AP-ES-07-16-06 1500EDT