NRS hands Trawsfynydd reactor buildings area to Costain
Costain's contract, awarded in October 2025, will cut both reactor buildings' height by nearly half.
Key facts
- Peak workforce on the project expected to exceed 100 Costain jobs, per NRS
- Large crawler cranes due on site later this year; two tower cranes follow in early 2027
- Crane already on site for scaffolding, hoist installation and electrical infrastructure works
- Project review completed, clearing the path to future demolition works
Nuclear Restoration Services has handed the reactor buildings area at Trawsfynydd to Costain, NRS said on October 8, allowing the reactor height reduction project to move from planning into on-site delivery.
The handover follows the award of the contract to Costain in October 2025. The project will reduce the height of both reactor buildings by nearly half. At its peak the programme is expected to create more than 100 jobs with Costain.
NRS and Costain have completed a review of the project confirming that plans and delivery arrangements are progressing as expected. Completion of the review was a step in allowing the programme to move towards future demolition works.
A crane is already on site for early activities including scaffolding, hoist installation and electrical infrastructure works. NRS said the most visible stage is expected to begin later this year, when large crawler cranes arrive. That will be followed in early 2027 by the erection of two large tower cranes inside the reactor buildings.
NRS said Trawsfynydd is one of its "lead and learn" sites, and that experience gained through the project will inform future decommissioning programmes across its estate.
