French nuclear research began for military purposes and then further developed for business. This article traces the history of French nuclear development from the establishment of the French Atomic Energy Commission in 1945 to the present by dividing this period into six phases. Contrary to previous studies which focus on certain periods, seventy years of French nuclear history is investigated here. It describes the transition from military to civilian use, the development of the nuclear fuel cycle including the fast breeder reactor, spent nuclear fuel reprocessing, and disposal research. Additionally, based on a historical case study of the Marcoule site, the oldest nuclear site in France, this article shows that France will rely on back-end nuclear technology to survive in the twenty-first century.