Changing face of Magnox decommissioning

25 November 2014

The UK's shut down Bradwell nuclear power plant is sporting a new look as cladding work progresses in preparation for care and maintenance. Meanwhile, UK construction and engineering group Costain plans to develop novel ways to treat irradiated graphite from decommissioned reactors.

Revealed: Bradwell's new look (Image: Magnox Ltd)

Decommissioning of Bradwell's two 125 MWe Magnox reactors has been under way since the plant shut down in 2002 after 40 years of service. All fuel was removed from the site by 2005, and the turbine hall demolished in 2011. The remaining reactor buildings and boiler houses are to be placed in long-term passive storage to allow time for residual radioactive materials to decay before final site clearance under a strategy known as Safestor.

The buildings are being sealed in aluminium cladding to provide protection from the weather during the care-and-maintenance phase, which could last until as late as the 2070s. To date, 7377 square metres of cladding, out of a total of 28,000 square metres, has been installed.

A central building linking the two reactor buildings at Bradwell has now been demolished, separating the two buildings and enabling further progress to be made with the installation of the cladding. Cladding has now been completed on one of the four boiler houses and has been fully revealed for the first time as scaffolding has been taken down.

Bradwell site director Scott Raish described the separation of the buildings as marking the end of an era for the site. "Now the buildings are separated, the work to clad the reactors can continue and we will begin to see more of what the site will look like in care and maintenance," he said.

Graphite grant for Costain

Meanwhile, UK engineering company Costain has announced it has secured £1m ($1.6 million) of funding from the UK government to support a project to develop a "new and innovative" method to treat irradiated graphite.

The large volumes of irradiate graphite used in the moderators of the UK's gas-cooled reactors present a decommissioning challenge, although the material is stable under Safestor conditions. Costain's research project, in partnership with MDecon, Tetronics International and the Universtiy of Manchester, aims to convert the graphite to carbon dioxide gas.

According to Costain's head of research and technology Bryony Livesey, the carbon dioxide could then be "incorporated into a carbon capture and storage scheme," concentrating the majority of the radioactivity into a small residue. "This approach will reduce the volume of material to be stored by about 95%, dramatically reducing overall costs," Livesey noted.

Costain says the three-year project will begin in April 2015.

Researched and written
by World Nuclear News