Magnox has dispatched the final flask of spent fuel from Wylfa Site on Anglesey for reprocessing at Sellafield in Cumbria, marking the end of de-fuelling operations at all of the UK’s first-generation nuclear reactors.

This is a major milestone for the twin-reactor site and its staff, who have removed the 87,890 fuel elements from the site — they are 43in long and would stretch for 17.5 miles if placed end to end. It means that more than 99% of the site’s radioactivity has now been removed.

Wylfa Site director Stuart Law said: “I am extremely proud of the whole team for working together to reach this important milestone in record time.

"It has not been an easy task, and the work at Wylfa is far from complete, but this is a significant landmark in the site’s journey towards care and maintenance.

"The de-fuelling process was hampered by ageing equipment for the first 18 months, which brought challenges, but the dedication and problem-solving abilities of the Wylfa team and expertise drawn from around the nuclear industry led to what is an incredible performance in completing this task.”

Wylfa Site, the last Magnox site to be built in the UK (and the biggest), operated safely from 1972 until 2015 and generated 232TWh of electricity — enough to power 1.1 million homes for 44 years.

Gwen Parry-Jones, Magnox CEO, said: “As the final Magnox site to de-fuel, this marks a significant landmark for the company as a whole in carrying out our mission to safely decommission our fleet, and it marks a new focus on the next phase for the whole company.”