Journalistic representations of a suicide pact in 1957 encapsulated wider popular assumptions on, and anxieties over, nuclear technology. Through an exploration of British nuclear culture in the late 1950s, this article suggests that knowledge of nuclear danger disrupted broader conceptions of self, nationhood and existence in British life. Building on Hecht's use of the term ‘nuclearity’, the article offers an alternative definition of the term whereby nuclearity is understood to mean the collection of assumptions held by individual citizens on the (...) dangers of nuclear technology: assumptions that were rooted firmly in context and which circulated in, and were shaped by, national discourse. The article will argue that nuclearity was an active component in the formation of British identity by the late 1950s. The article is intended as a starting point for extended reflections on the ways in which nuclearity can add to our understanding of individual experience, nuclear anxiety and Cold War culture in post-war Britain. (shrink)