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Green GB Week sees Magnox’s double platinum jubilee

In the first ‘Green GB Week’ to celebrate clean growth, 2 Magnox sites in North Wales have reached landmark anniversaries.

This was published under the 2016 to 2019 May Conservative government
Constructing Maentwrog Dam (1926)

Constructing Maentwrog Dam (1926)

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

Construction of both sites were incredible feats of pioneering 20th century engineering which, for Maentwrog, included the formation of the second largest man-made lake in Wales with the construction of its 4 concrete dams.

Maentwrog hydropower station: 90 years of sustainable generation

Trawsfynydd stopped generating electricity in 1991 but Maentwrog’s 30 megawatt power station has continued to generate carbon-free electricity, supplying around 4,000 gigawatts of to the National Grid over the last 90 years which is enough to power all the homes in Wales for 6 years.

Rainwater is collected from across the Snowdonia National Park through a network of rivers, leats and streams that feed into Trawsfynydd Lake. The water surges down 2 high pressure pipelines, at more than 4,000 gallons per second, to drive 2 turbines generating electricity. Just one inch of rainfall creates 24 hours of electricity generation.

Maentwrog Dam (present day)

Maentwrog Dam (present day)

Station Manager, Andy McAteer, commented:

Maentwrog has been operating since 1928 and will carry on harnessing this carbon-free energy source long into the future. We’ve got a close-knit team that has a unique opportunity to work on the site, knowing that we are only stewards of this beautiful and well-designed site looking after it for future generations.

Maentwrog’s younger cousin, Trawsfynydd Site, has had a successful year of decommissioning progress with many of the clean-up and hazard reduction projects coming to a successful end:

  • hundreds of thousands of litres of radioactive waste have been safely retrieved, packaged and placed in the site’s interim term storage facility
  • 3,300m2 of concrete walls and floors in the site’s former cooling ponds complex has been decontaminated
  • over 1km of pipework has been removed
  • several redundant buildings have been demolished
  • 12,000kgs of a radioactive waste material known as ‘fuel element debris’ – created when the site was generating electricity - has been recovered and placed in safe storage

Trawsfynydd and Maentwrog sites are owned by the government’s Nuclear Decommissioning Authority (NDA), the organisation responsible for cleaning up 17 sites dating back to the earliest days of the nuclear industry.

Trawsfynydd: 50 years since it opened

Nuclear Energy Minister Richard Harrington:

For 90 years Wales has been pioneering the UK’s move to a greener, cleaner economy producing low-carbon electricity and during our first ever Green GB Week it’s encouraging to see how the UK’s Nuclear Decommissioning Authority is also leading the world in decommissioning by cleaning up the UK’s legacy nuclear sites in Wales.

The NDA’s Director of Nuclear Operations, Alan Cumming, said:

Our sites were built by pioneers of the nuclear industry. These sites were ‘world’s firsts’ when they were built and they made a remarkable contribution to this country throughout the 20th century.

Today, the UK is at the leading edge of nuclear decommissioning as we safely pioneer approaches to cleaning up the legacy from the earliest days of the nuclear industry, while delivering value for the UK taxpayer.

Updates to this page

Published 17 October 2018
Last updated 19 October 2018 + show all updates
  1. Added YouTube videos

  2. Added links to the YouTube video material

  3. First published.