Coexistence of new metals with liquid alkali metals, (3)

Section seven deals with the coexistence of vanadium alloys for FBRs with liquid sodium. The conclusion of the study in Argonne, the experiment on a series of Vanstar alloy developed by Westinghouse, and the experimental study on V-20Nb-10Mo, V-20Nb-5Cr and V-20Nb-5Al using a small Na-loop made by Research Institute for Metallic Material Technology are reviewed. The experimental study revealed that the coexistence of vanadium alloys with liquid sodium can be determined by the degree of embrittlement due to oxygen in vanadium alloys, and that the test of tensile strength after immersion in sodium and the analysis of nonmetallic elements in vanadium alloys are effective as means of the evaluation of coexistence. Further, the experiment showed that V-20Nb-5Cr was relatively better among the compared vanadium alloys. Section eight deals with the coexistence of new metals for CTR with liquid lithium. Method of eliminating impurities in liquid lithium and method of measuring concentration are reviewed. Corrosion was compared among various metallic materials in liquid lithium. The group IV-A, V-A and VI-A metals have good and reliable corrosion resistance. The effect of oxygen on the coexistence of V, V-20Ti, Nb and Ta with liquid lithium is reviewed. The effects of O, N and C on the coexistence of new metals for CTR with liquid lithium are reviewed. Attention is drawn to the need of development for controlling and monitoring the concentration of O, C and N in liquid lithium. (Iwakiri, K.)