In spite of much effort to the contrary, nuclear energy and nuclear weapons are often closely related in our minds. Both appeal to the imagination, under the vocable of atomic in the early years, nuclear today. It is undeniable that the physics principle that lies behind both is the fission of the atomic nucleus, releasing large amounts of energy. Nuclear weapons soon have included the even more powerful mechanism of fusion into their designs but also for the generation of electricity fusion represents the ultimate goal of harnessing the atom. The remarkable parallel between military and civilian applications is a constant feature in the development of technology. In this article we explore the links that are made between nuclear energy and nuclear weapons by government actors and civil society. Without expressing ourselves on the nuclear power industry, we argue that in order to achieve progress in nuclear disarmament, it is necessary to decouple both.