ANALYSIS OF V-CR-TI ALLOYS IN TERMS OF ACTIVATION OF IMPURITIES

Vanadium alloys offer many advantages including reduced neutron activa tion. However, activation of V-Cr-Ti alloys is controlled by impuritie s. This study analyzes four impurity levels for the alloy V-4Cr-4Ti. T he first Is an existing commercial heat of the alloy and the others ar e based on impurity levels attainable by three processes. One process uses a dedicated production plant: another uses a chemical recrystalli zation process, and the remaining one uses state-of-the-art laboratory purification. It was assumed that the alloys were irradiated as first wall and blanket structures in a fusion reactor operating for four fu ll power years at a wall loading of 5 MW y/m(2). It was found that the two purest alloys and, with special selection, the three purest alloy s will meet the criteria for shallow land burial after a cooling time of 50 years. However, none of the alloys were found to meet the criter ia for hands-on reprocessing after a cooling time of 100 years. (C) 19 98 Published by Elsevier Science B.V. All rights reserved.