Fusion reactor materials to minimize long-lived radioactive waste

Abstract

Abstract This paper examines, in relation to the norms and practices now applied in different countries, the prospects for the storage and disposal of the radioactive wastes to be expected from future fusion power plants. There is at present no regulation in Europe that defines the treatment and the allowed concentration of the possible long-lived nuclides of waste to be disposed of in shallow land burial. There are a few sites of this type, each one having different acceptability criteria. In the USA the norms applicable are those of the Code of Federal Regulation (10CFR61) which could be logically and consistently extrapolated to fusion materials. The knowledge of the acceptability index of the elements appears to be quite useful in improving the composition of fusion reactor materials, in particular for the first wall and the breeding blanket. These indices, or waste disposal ratings, have been computed either with reference to the UK site norms, which are at present the most restrictive in Europe, or with reference to be extrapolated US norms. The conclusion is relatively optimistic in the second case and less so in the first. The state of the activation cross sections is also examined and recent progress, particularly in the data needed for long-lived radioactive nuclei, is reported.