The battery and the military context
Nuclear accidents - Windscale (United Kingdom)

The ministerial decision to build British atomic bombs was taken in January 1947, despite the post-war policy of austerity, and revealed to Parliament in May 1948. Time was of the essence, with the USSR having detonated its first atomic bomb in September 1949.

A process and site had to be chosen to produce weapons-grade plutonium.

The site chosen was that of a former munitions factory, in a then sparsely populated area of Cumberland on the Irish Sea, called Sellafield, but renamed Windscale.