Though it’s also worth pointing out that Sellafield is Europe’s largest nuclear site and has operated since the 40’s and suffered the disaster in 1957 when reactor design, nuclear safety and safe handling were in their infancy, and the world was just starting to explore harnessing nuclear power generation.
And also to be more relevant to the subject of the article; this is one of the reasons why fusion should be being researched, much lower chance of problems arising from waste/risk of meltdown etc.
Fusion isn’t fission, it could provide relatively cheap and clean nuclear power.