Radiation damage, at high temperatures.

The successful development of nuclear power reactors that are economically competitive with other sources of energy has led us to believe that more economical reactors will be developed. But, in developing the next generation of reactors, a new set of problems must be overcome. One of the most important of these is that of the embrittlement of the structural materials at high temperatures as a result of the intense neutron fields in these advanced systems. The radiation-induced embrittlement at high temperatures is probably associated with helium produced in the materials due to (n,alpha) reactions with the metal, and in some alloys radiation-induced precipitation of compounds within the alloy may also play a role. We believe that the most serious longterm problem is the generation of helium. Our current understanding of the mechanism by which this radiation damage is produced has allowed us to effect some improvement in the behavior of conventionally produced structural alloys, through minor modifications of the normal working and annealing processes used in their manufacture. However, we may find that new alloys will have to be developed to withstand the service conditions in future nuclear power reactors.