Since public understanding of the environmental consequences of new technologies is needed for informed decision-making, it is necessary to find a more effective alternative to the massive environmental statements that have been the result of pressure from the courts and from the opponents. A simplified conceptual framework for assessing the environmental impacts of a new energy system should include the benefits to be derived from the technology, the internal and external costs to man and to society, and a comparison with other alternatives. The first step in making such an analysis for breeder reactors is to define the need for a breeder system, the desired effects of the technology, and the probability of success and timing of the developments. The heart of the assessment is the estimation of the external costs including impacts on human health, on human environment, and on the social system. The final step is that of comparing the impacts of breeders with the impacts of alternatives and putting these into perspective with other risks and environmental costs for public understanding.