[en] The imperceptible character of nuclear radiation on the human senses and their harmful effects on living beings and the environment is emphasised. This is based on a review of published works about the concepts of energy and ecology. The potential hazards of a possible nuclear accident and the damage it would cause to a community as well as the problem of radioactive waste disposal are raised. The conclusions and recommendations of the Brazilian Physics Society's Report on Nuclear Pollution are endorsed. The general guidelines of Brazilian Legislation are presented. The legal aspects of nuclear reactor licensing in West Germany, the United Kingdom, France and Brazil are shown from the point of view of the applicable legal system, the licensing bodies, the general frame and scope, public participation, technical safety bodies, as well as the inspection procedures. The concepts of absolute and objective civil responsibility for nuclear damage are reviewed. The judicial principle of equity is considered in view of the exceptional character of the nuclear risk. The main aspects of the international Conventions of Paris, Brussels and Viena on civil ability of nuclear damage are presented. Some philosphical and judicial questions are discussed emphasising the instrumentality of the law control and effective protection. The final suggestion is the exchange of ideas with a view to obtain the maximum safety in the operation of nuclear installations. (author)