Mott MacDonald designing weather envelope at Bradwell power station, UK

Mott MacDonald is acting as the designer to Vinci Construction Limited, on behalf of Magnox Limited, for the design and build of an approx £20 million weather protection envelope at Bradwell power station in Essex, UK.

The two reactor buildings at the Bradwell site each consist of a reactor, two boiler houses and two circulator halls encompassing a 26,000m² surface area. The weather envelope will cover and protect both buildings on site.

Graham Cotton, project manager at Magnox Ltd which manages the site on behalf of the UK's Nuclear Decommissioning Authority (NDA), said: “The weather envelope is a critical milestone towards reaching care and maintenance on the site, which will see it placed into passive storage in 2015.”

The 'care and maintenance' stage of decommissioning is when the reactor buildings are placed in a passive state, known as Safestore, and are monitored and maintained until the site is completely cleared in about 65 years' time. By this time the residual radioactivity will have decreased significantly.

The design life of the weather envelope will be achieved through a weather tight cladding design and passive ventilation system to reduce condensation at the site and remove the need for maintenance activities. Passive ventilation is essential as a key goal of the project is to reduce the need for inspection and maintenance activities as well as the requirement of personnel on site. To design the most effective passive ventilation system, Mott MacDonald building services engineers are modelling the internal environment for a range of external ambient conditions.

The consultancy has also undertaken a 3D scan of the buildings and will be producing a computer aided design as built model. This will assist in assessing the capacity of the buildings to withstand environmental loads such as wind and snow.  The model will also be a key element for undertaking the design of building strengthening modifications and the weather envelope cladding system. 

Project director Tony O’Gara said: “Mott MacDonald is pleased to be working with Vinci Construction Ltd on this challenging and important project. The collaborative approach between the two organisations and the client is the key to delivering this critical piece of work successfully”


Media Enquiries:

Tom Smith
44 (0) 20 8774 2205

Christina de Burgh-Milne
44 (0) 20 8774 3639

Lee Lodge
44 (0) 20 8774 2040


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