[en] A survey is presented of nuclear safety in the US and in France and of IAEA activities in this area. The two countries have been selected because the US ranks first in the world in the number of nuclear power plants and installed nuclear capacity (ca 1/3 of total world installed nuclear capacity) and France because of the proportion of electric power generated by nuclear power plants (70%) which ranks in the world first in this respect. It also ranks first in the dynamics of its nuclear program. The study only deals with civilian light water reactors and emphasis is put on the safety of the primary coolant circuit, mainly the reactor core. The four-part study discusses the content and aims of research. IAEA program and activities, safety research in the US and in France. Research of the external fuel cycle is not included. (author). 14 refs