Costain to prepare Trawsfynydd for Safestore

08 March 2013

Costain will reinforce the reactor buildings of the Trawsfynydd nuclear power plant under decommissioning as part of its second contract from Magnox for work at ten UK sites being prepared to enter care and maintenance.

Trawsfynydd (Magnox) 460x284
Trawsfynydd (Image: Magnox)

The project is worth some £2.7 million ($4.0 million) and involves reinforcing the upper structure of the Trawsfynydd reactor buildings to make them safe before they are reduced in height at a later date. The project includes improving the integrity of the structures with specially designed steel sections attached to the internal surfaces of the reactor buildings. At a height of almost 52 metres, the job includes the careful design and provision of scaffolding and access platforms, putting in place intricate lifting plans - all with due consideration to the possible presence of asbestos.

Costain's operations director for nuclear process Chris Scott commented, "Safety is paramount on this project. Not only are we working at a considerable height, but we also need to improve the integrity of the structure by pinning steel bars to the inside of the walls and bracing the concrete structure. The building has been partially eroded by the elements and we have to ensure that the strengthening project provides the integrity the building needs to get them safely through to the next phase of decommissioning."

The 392 MWe Trawsfynydd plant began operation in 1965 and was retired in 1991. Since then all the fuel has been removed from the twin reactors. In around 2016, the plant will be placed in a passive state, known as Safestore, and will be monitored and maintained until the site is completely cleared around 2070, by which time the residual radioactivity will have decreased significantly.

In September 2012, Costain and Balfour Beatty were awarded a framework contract worth £288 million ($430 million) for construction work at ten Magnox sites in the UK. Between them, the companies will deliver design, construction and maintenance of permanent buildings and structures, infrastructure maintenance and extension work incorporating construction and civil engineering structures and ground work projects.

Costain was one of six companies to be awarded a framework contract by Magnox in 2011 to provide waste retrieval, processing and filling services at eight of their nuclear power plant sites as part of a joint venture with Amec and Jacobs Engineering Group.

Researched and written
by World Nuclear News