Prestressed concrete containment structures can withstand the highest pressures resulting from the worst accident conditions postulated for liquid-metal fast breeder reactor plants. However, in addition to pressure loads, other potential hazards exist, such as internally generated missiles, hydrogen deflagration, and sodium fire. The latter is potentially the most critical because of the high temperatures that are involved. Preliminary indications are that with a reasonable research effort focused on experiments, appropriate constitutive models, and innovative design concepts, it would be shown that this threat could also be contained. The research is proposed because there is a good possibility that prestressed concrete could withstand in a completely passive mode all of the accident scenarios that are currently being postulated. If this could be shown in a definitive sense, the social and economic benefits would be very significant.