Decommissioning milestone reached at Trawsfynydd nuclear site

Mark Mansfield

A major milestone has been reached in the decommissioning of Trawsfynydd nuclear power station after the completion of a 20-year programme to remove and safely store the site’s highest-priority radioactive waste.

The former power station in Gwynedd, the UK’s only inland nuclear power station, has now completed its Higher Activity Waste (HAW) programme, which dealt with the most hazardous radioactive material remaining on the site. The final waste package has now been transferred into long-term storage, bringing the campaign to a close.

Trawsfynydd generated electricity for almost 30 years before closing in 1991. Since then, work has focused on managing the site’s radioactive legacy and preparing it for long-term decommissioning.

The HAW programme involved retrieving, processing and packaging intermediate-level radioactive waste for secure storage, with almost 2,300 individual waste packages completed over the course of the project.

Rob Fletcher, chief executive of Nuclear Restoration Services (NRS), described the achievement as a landmark moment in the site’s history.

He said: “This is not just the end of a major programme, it is the end of an era.

“Completing this work safely and successfully has allowed Trawsfynydd to move into its next phase of delivery, reducing the height of the reactors by almost half. This will create the most noticeable change to the landscape in decades.”

Teams working on the programme developed a number of specialist techniques to recover waste from difficult-to-reach locations, including the use of robotic arms and vacuum systems to remove radioactive material from deep storage areas. Knowledge gained from the project has since been shared across the UK’s wider nuclear decommissioning programme.

Tom Williams, NRS site director at Trawsfynydd, paid tribute to the workforce involved in the project.

He said: “Bringing the HAW programme to a close is a remarkable achievement for everyone at Trawsfynydd.

“Its completion represents a key delivery milestone in our decommissioning mission; one we can look back on with pride whilst also looking forward with excitement to the start of our new major projects.”

Next phase

Attention will now turn to the next phase of decommissioning. Last year, Costain was appointed to lead a project worth up to £70 million to reduce the height of the reactor buildings from around 54 metres to 29 metres. The work is expected to take up to four years and support more than 100 jobs at its peak.

Clive Nixon, chief nuclear strategy officer at the Nuclear Decommissioning Authority, said the completion of the waste programme represented significant progress in the clean-up of Britain’s oldest nuclear sites.

He said: “This milestone demonstrates the significant progress we are making in delivering on our mission, set on behalf of government, to safely, securely and cost effectively clean up the UK’s earliest nuclear sites, prioritising the reduction of the highest hazards and risks while protecting people, communities and the environment.

“We look forward to the next phase of work, which will see the height of the reactors reduced, taking a big step towards their dismantling, as we progressively deliver on our mission to decommission the site.”