WISCASSET – Maine Yankee’s most visible landmark, its 15-story reactor containment dome, is slated for demolition around Labor Day.

Explosives will be used to blow out the dome’s foundation, causing it to collapse, William Henries, Maine Yankee’s director of engineering, told the Community Advisory Panel on Decommissioning on Thursday night.

“When it hits the ground, it is going to go bang,” Henries said.

Maine Yankee will take steps to ensure that the resulting aftershock will not knock out vibration-sensitive relays at a nearby Central Maine Power switching station, Henries said.

The company plans to evacuate a nearby office building because the impact from the 20 million-pound dome could shatter windows.

The advisory panel also heard from a U.S. Department of Energy official, who provided an update on plans for storage of high-level nuclear waste.

Senior policy analyst Susan Smith said the government would like to see Yucca Mountain in Nevada begin accepting nuclear waste in 2010. But Smith was unable to provide assurances that Maine Yankee waste now stored in Wiscasset would be given priority at the site or that the Yucca Mountain facility would actually be operating in six years.

A more likely date, according to Maine Yankee Vice President and Chief Operating Officer Michael Meisner, is 2023.

The project faces financial and legal hurdles. The state of Nevada is suing the Department of Energy, claiming the site is ill-suited for such a use. And Maine Yankee is one of 65 utility companies nationwide suing the department for breach of contract over delays in accepting nuclear waste. The target date had been January 1998.

Maine Yankee, which is being joined in the legal action by Yankee Rowe and Connecticut Yankee, is seeking $160 million in damages, spokesman Eric Howes said. The so-called “Yankees suit” is scheduled to begin next month in the U.S. Court of Claims.