Windscale in Cumbria suffered serious damage in a fire in 1977. The incident was hushed up although many suffered from the outcome with cancer resulting in death of many. A Wikipedia article states: "the Windscale fire of 10 October 1957 was the worst nuclear accident" in the U.K. It has been estimated there have been 100 to 240 cancer facilities in the long term, with people still suffering it's effects now in 2023. It is etsimated it will take 100 years to clear up "the mess" at a cost of £260 billion.
A number of eminent people gave evidence at the Windscale Public Inquiry, 1977 who had become convinced of the dangers of pursuing a nuclear future and re-opening Windscale. They included Arthur Scargill, President of the National Union of Mineworkers (Yorkshire Area) and Chairman of Energy 2000, Sir Kelvin Spencer, Ministry of Power Chief Scientist (1954-1959), Colin Sweet, expert in the economics of nuclear power, Lesley Grainger, National Coal Board Member, Gordon Thompson, expert on the potential fallout from nuclear accidents
and Sister Rosalie Bertell, expert on leukaemia caused by nuclear radiation.
All gave evidence against nuclear power.
Concerned scientists have given an acoount of accidents which have occurred in nuclear power plans globally: https://www.ucsusa.org/resources/brief-history-nuclear-accidents-worldwide