IN the UK’s first ‘Green Great Britain Week’, two Magnox sites in north Wales have reached landmark anniversaries.

This week marks 50 years since Trawsfynydd nuclear power station officially opened on 18 October 1968, and 90 years since Maentwrog Hydro-electric station began generating carbon–free electricity on 15 October 1928.

Construction of the two unique sites were incredible feats of pioneering 20th-century engineering which, for Maentwrog, included the formation of the second largest man-made lake in Wales and its four concrete dams.

Although Trawsfynydd itself ceased generating electricity in 1991, Maentwrog’s 30 megawatt power station has supplied 4,000 gigawatts of carbon-free energy to the National Grid in the last 90 years – that’s enough to power all the homes in Wales for almost six years.

Rainwater is collected in a series of rivers, leats and streams that feed into Trawsfynydd Lake and carried by a two mile long network of tunnels and steel pipelines that snake across the countryside before surging down two high pressure pipelines at more than 4,000 gallons a second to drive the two turbines below. Just one inch of rainfall creates 24 hours of electricity generation.

Station manager Andy McAteer said: “Maentwrog has been operating since 1928 and current intentions are to operate the site to at least 2084. Our team, past and present, have all enjoyed the variety of work, in all weathers, knowing that we are only caretakers of this beautiful and well-designed site for future generations.”

It has been a great year of decommissioning progress at Trawsfynydd Site with many of the decommissioning, clean-up and hazard reduction projects coming to a successful end.

Hundreds of thousands of litres of radioactive liquid, resin and sludge have been safely retrieved, conditioned, packaged and placed in the site’s interim term storage facility. 

These intermediate level wastes accumulated during the 26 years Trawsfynydd generated low carbon electricity.

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