AP / Wideworld Preparation for tower demolition at congested site took two years.

Within a few minutes of each other on Sept. 29, two pairs of cooling towers at the world’s first nu­clear powerplant disappeared from Sellafield’s skyline on the English coast. Their controlled explosions had been two years in the making.

Demolishing the 91.1-meter-tall towers for Calder Hall generating station’s four gas-cooled reactors was the most visible part of a program to remove hundreds of buildings at the 4-sq-kilometer nuclear site, and clean up after 60 years’ military and civil nuclear activity.

Toppling the towers went as planned, says Andy Scargill, decommissioning and clean-up superintendent for operator British Nuclear Group. “We had to go through a lot of steps to make sure the regulator was happy,” says Scargill. Of more than 200 towers demolished in the U.K., none was sited within 40 m of a nuclear fuel-handling plant.

BNG’s tower team, headed by Dyan Foss, probed in detail a range of risks, such as debris spread, projectiles and vibrations. Despite a dearth of recorded information, BNG produced “a complete historical evaluation of cooling towers and historic demolition methods, hazards and controls,” says Foss.

The final demolition procedure went as first planned, with one significant modification. As well as blasting 60% of towers’ supports, Controlled Demolition Inc., Phoenix, Md., detonated a vertical slot in each shell to aid its fracture.

BNG is spending around $1 billion a year cleaning up and demolishing facilities as Sellafield’s life nears its end next decade. Demolition and clean-up ac­count for a fifth of that budget. Handling 75 proj­ects, Scargill manages some 800 Sellafield and subcontractor staff. Among the projects is demolition of a 125-m-tall chimney, contaminated by a reactor fire.

Phasing out Sellafield is uniquely complicated, says Scargill. U.S. facilities may be bigger, “but this is the only site in the world that has one of everything and sometimes two or three,” he says, including weapons manufacturing facilities, powerplants, vitrification plants and waste storage. And working around operational plants adds complexity.

Within a few minutes of each other, two pairs of cooling towers at the world’s first nuclear powerplant disappeared from Sellafield’s skyline, on the English coast on Sept. 29. Their controlled explosions had been two years in the waiting.

Demolishing the 91.1-m-tall towers for Calder Hall generating station’s four gas-cooled reactors was the most visible part of a program to remove hundreds of buildings at the 4-sq-km nuclear site, and clean up after 60 years’ military and civil nuclear activity.

Toppling the towers went as planned, says Andy Scargill, operator British Nuclear Group’s Sellafield decommissioning and clean-up superintendent. “We had to go through a lot of steps to make sure the regulator was happy,” says Scargill. Of more than 200 towers demolished in the U.K., none was sited within 40 m of a nuclear fuel-handling plant.

BNG’s tower team, headed by Dyan Foss, probed in detail a range of risks, such as debris spread, projectiles and vibrations. Despite a dearth of recorded information, BNG produced “a complete historical evaluation of cooling towers and historic demolition methods, hazards and controls,” says Foss.

The final demolition procedure was as first planned, with one significant modification. As well as blasting 60% of towers’ supports, Controlled Demolition Inc., Phoenix, Md., detonated a vertical slot in each shell to aid its fracture.

BNG is spending around $1 billion a year cleaning up and demolishing facilities as Sellafield’s life nears its end next decade. Demolition and clean-up account for a fifth of that budget. Handling 75 projects, Scargill manages some 800 Sellafield and subcontractor staff. Among the  projects is demolition of a 125-m-tall chimney, contaminated by a reactor fire.

Phasing out Sellafield is uniquely complicated, says Scargill. U.S. facilities may be bigger, “but this is the only site in the world that has one of everything and sometimes two or three,” he says, including weapons manufacturing facilities, powerplants, vitrification plants and waste storage. And working around operational plants adds complexity.

On top of all that, BNG faces a shake-up at the top. The Nuclear Decommissioning Authority has ended initial negotiations with four consortiums bidding to manage Sellafield. It aims to award a contract next summer. The winner will field a small team to manage 8,000 staff undertaking $2.4 billion of work a year, including operational.

One of the team’s tasks will be to change Sellafield’s culture from that of  a production plant to a project, says NDA's program director Mark Dixon. The culture may now not be right, but “the technical ability is all there,” he says.