ZR-NI ALLOYS AS CANDIDATE GETTER MATERIALS FOR TRITIUM PROCESSING

Reversible tritium getters are indispensable for the safe handling of a large amount of tritium in the fuel processing for thermonuclear fusion reactors. In Zr-Ni metallic compounds, we looked for the reversible getters showing the heat of deuteride formation around -25 kcal/mol (D2) which will be appropriate to the storage-supply-recovery of tritium. Among five metallic compounds used in this study, we found that the first plateau for ZrNi and Zr9Ni11 showed DELTA-H0 congruent-to -25 kcal/mol (D2). The second plateau for ZrNi gave DELTA-H0 = -19.2 kcal/mol (D2). This suggests that ZrNi is also applied as the source of tritium supply near one atmosphere at relatively low temperature (260-degrees-C). They were withstanding pulverization and nonflammable against air exposure. In addition, ZrNiD2.3 was reactivated quite easily with vacuum heat at 300-degrees-C even after air exposure. Those properties of ZrNi and/or Zr9Ni11, are quite promising as the reversible tritium getter in the fuel processing for thermonuclear fusion reactors.