Believing in Breeding: The Transformations of a Nuclear Utopia

Since the 1930s, nuclear specialists have been driven by an idea based on a neutron equation: by converting uranium 238 into plutonium in suitable nuclear reactors, the available resource would be multiplied by 100. This idea, opening the way to a horizon of abundance and material equilibrium, has come to be known as fuel “breeding”. Although it motivated numerous technical and scientific programs, the vast majority of these have since been halted. How can we explain the longevity of the idea of breeding, despite the épreuves it has endured? This article is organized around the hypothesis that breeding is a technical utopia, and examines the different forms that belief in this utopia has taken within expert communities in France since the 1970s. Breeding certainly appears as the culmination of humanity’s energy history, in a context where collective choices are structured by the knowledge of technicians - what we call the “major mode” of utopia. But it also appears as an idea in the process of finding material translations - where technical utopia becomes the object of testing, discussion and postponement. Finally, it survives by taking the form of an insurance technology in the event of a supply crisis, whose availability must be maintained - what we refer to as the “minor mode” of utopia.