The Chernobyl disaster of 1986 had international repercussions, as nuclear fallout, and accompanying fear, traversed well beyond the borders of the Soviet Union. In Britain, raised radioactivity levels caused some upland regions, such as north-west Wales, to become subject to restrictions on the sale of livestock, which created upheaval for the agricultural community, leading to an uncharacteristic outburst of protest from farmers who were unhappy with the government's response to the crisis. Concurrently, nuclear sceptics in Wales attempted to politicise the tragedy in the Ukraine to underline the dangers of nuclear power, dovetailing the accident with the looming perils of Wales's domestic nuclear industry. In exploring these issues, this paper contributes to a growing body of work on ‘British nuclear cultures’, moving away from its generally urban focus by examining a Welsh rural case study. This approach also circumvents the well-trodden historiographical narrative surrounding the politics of nuclear warfare by highlighting debates arising from civil nuclear power. Crucially, the work demonstrates how looking at the modern Welsh past through the prism of a transnational nuclear event such as the Chernobyl catastrophe shows that the history of twentieth-century Wales is enriched by moving beyond the stereotypically ‘Welsh’ industrial shibboleths of the south Wales coalfield and the slate mines of north Wales.