This article examines the responses of Welsh poets, writing in both English and Welsh, to nuclear power in the period after the Chernobyl disaster of April 1986. Fall-out from Chernobyl contaminated upland areas of North Wales adjacent to the country's two nuclear power stations, Trawsfynydd and Wylfa, prompting a backlash against the nuclear industry. Welsh poets played key roles in the anti-nuclear movement during the 1980s and 1990s, writing poems that respond both to the Chernobyl disaster and to nuclear threats closer to home. Furthermore, we trace the long aftermath of Chernobyl in the poetry of R.S. Thomas and Robert Minhinnick, which is frequently contaminated with the imagery and vocabulary of nuclear disaster.