Trawsfynydd site

Trawsfynydd sits within a 15 hectare site in the Snowdonia National Park – home to the UK’s first inland civil nuclear power station. Since decommissioning began in 1995, the site has delivered major achievements, including bulk asbestos removal and the demolition of both the turbine hall and administration complex.

A new era of transformation begins in 2026, as a four‑year programme gets underway to reduce the height of the two 54‑metre reactor buildings to around 25 metre. This will reshape the skyline and mark one of the most ambitious decommissioning engineering projects in Wales.

The site has also reached a historic waste‑management milestone. After two decades of meticulous and technically demanding work, almost 2,300 packages of post‑operational intermediate‑level waste have been safely retrieved, processed and placed into the site’s interim storage facility, with the final package transferred in March 2026. This achievement reflects years of expertise, collaboration and commitment to safe decommissioning across the organisation.