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 ΔH0≅-25 kcal/mol (D2). The second plateau for ZrNi gave ΔH0=-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 (260deg C). They were withstanding pulverization and nonflammable against air exposure. In addition, ZrNiD2.3 was reactivated quite easily with vacuum heat at 300deg 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. (orig.)