Explosives Bring Down Maine Yankee’s Containment Dome

Tue October 05, 2004 - Northeast Edition
Construction Equipment Guide

WISCASSET, ME (AP) With a thunderclap of explosives, Maine Yankee’s containment dome toppled to the ground Friday, Sept. 17, in one of the final steps toward completion of the nuclear power plant’s decommissioning.

Several hundred people gathered on Maine Yankee property and from other vantage points to watch as explosives were used for the first time to knock down a commercial reactor containment building.

The 150-ft. tall structure served as the most visible symbol of the 900-megawatt plant during 24 years of operation.

Dudley Leavitt Sr., who helped build the dome, looked on with a tinge of sadness. He said he thought the plant had a lot more life left in it.

“It’s a shame that they shut this down. There are plants that are older that are still in operation across the country,” said Leavitt, of Topsham, who supervised steel reinforcement of the containment building.

Approximately 1,100 lbs. of explosives were placed in holes drilled into the structure to topple the reinforced concrete dome that was designed to withstand earthquakes, tornadoes and hurricane-force winds.

Thick fog obstructed the structure an hour before its demolition but gave way before the explosives were detonated at 10:08 a.m.

As the countdown concluded, there was a brief flash followed by a concussion, then walls supporting the dome buckled and the structure collapsed in one piece on top of a pile of rubble as planned.

Onlookers burst into applause as a cloud rose from the pile and filled the air with fine dust particles.

Steve Ward, Maine’s public advocate for utility issues, had mixed emotions about what he witnessed.

Maine Yankee provided low-cost energy for years without producing greenhouse gases, Ward said, but the problem of long-term storage of the nuclear fuel assemblies has never been resolved.

Approximately 50 yds. from the spectators, the fuel assemblies were stored in 60 canisters that will remain indefinitely.

“The federal government has utterly failed to deal with the spent fuel issue. It’s like building a wonderful, livable mansion that has no septic system. It doesn’t even have an outhouse,” he said.

Ray Shadis, a nuclear power opponent who lives in neighboring Edgecomb, noted that the dome was part of the landscape for years and could be seen above the trees from homes near the plant.

“This is strictly symbolic and nothing more,” he said of the demolition, calling it just another step in the lengthy decommissioning process. “It’s the last major demolition activity.”

In advance of Friday’s blast, a steel plate lining the structure was removed and holes were cut to weaken the structure, whose steel-reinforced walls were 4.5 ft. thick at the base and 2.5 ft. thick at the top.

The explosives were not designed to reduce the dome to rubble. The idea was simply to lower the dome so it could be reached by heavy equipment that would complete the job of picking apart the structure.

Approximately 20 million lbs. of rubble from the building will be hauled by rail to a low-level radioactive waste repository in Utah.

The pressurized water reactor began operation in 1972 and survived three statewide referendums aiming to close the plant in the 1980s.

It was shut down following operational problems that escalated after the discovery of cracked steam generator tubes in 1994. Problems continued to mount in 1996 and the plant was placed on the Nuclear Regulatory Commission’s list of worst-run plants in January 1997.

Maine Yankee’s board voted to close the plant permanently in August 1997, 11 years before the plant’s license was set to expire.

Manafort Brothers Inc., of Connecticut, is leading the decommissioning and Controlled Demolition Inc., of Maryland, was hired for the job of bringing down the domed containment building.

By the time decommissioning is completed next year, it will have cost $500 million. All that will remain are a security building and the storage facility where canisters hold the highly radioactive fuel rods.

Those spent fuel assemblies will remain until the federal government follows through with its promise to build a repository for high-level radioactive waste. The earliest that is expected to happen is 2010.

AP Photo: The dome that housed the nuclear reactor at the decommissioned Maine Yankee nuclear power plant begins to drop during an implosion, Friday, Sept. 17, 2004, in Wiscasset, ME. With a thunderclap of explosives, Maine Yankee’s containment dome toppled to the ground in one of the final steps toward completion of the nuclear power plant’s decommissioning.