A study of surface pretreatment of tritium-getter alloy for enhancement of insensitiveness to impurities

一些zirconium-alloy获取器预计将用于核聚变反应堆的燃料循环中的氚分离、净化和储存。We have been investigated particle beds of Zr， ZrCo， ZrNi and Zr D22-D2Fe which can recover the tritium concentration in gas streams lower than the maximum permissible level for the radioisotope in Japan。However， once tritium-getters contact with any of the gaseous impurities such as Oy D22 Yy D2，Hy D22 Yy D2O and CO， they lose most of their hydrogen capacities。基于我们先前关于在闲置床上大规模转移过程的实验研究，以及新的表面预处理技术，这些技术被测试以保持高吸收能力的增强不敏感性。The three surface pretreatment techniques are （1） alkali pretreatment， （2） pd depositing （3） Cu depositing。在1998年，我们比较地研究了对Zry-D22-D2 Fe getter的表面处理，并且在alkali Pre处理后的氢化速率提高了大约10次，比非处理的getter更快。它在房间温度下发现了一种预先处理过的Zr-D2 Fe颗粒，但不能吸收比检测限制少的三分之一。在1999年，甲基和氚水蒸汽被Zr打碎（Mn Yy D20.5 Yy D2 Fe Yy D20.5 Yy D2）Yy D22 Yy D2床被实验调查。Methane at higher than 650 D1 D1C and water vapor at 350 D1 D1C were successfully cracked by the Zr（Mn D20. 5 D2 Fe D20. 5 D2）D22 D2 bed。在目前的研究中获得的结果已在聚变核技术国际研讨会上提出，以及在氢能方面也曾被报道为国际期刊。

Some zirconium-alloy getters are expected to be used for tritium separation, purification and storage in a fuel cycle of a nuclear fusion reactor. We have been investigated particle beds of Zr, ZrCo, ZrNi and ZrィイD22ィエD2Fe which can recover the tritium concentration in gas streams lower than the maximum permissible level for the radioisotope in Japan. However, once tritium-getters contact with any of the gaseous impurities such as OィイD22ィエD2, HィイD22ィエD2O and CO, they lose most of their hydrogen capacities. Based on our previous experimental studies on mass-transfer processes in alloy beds, new surface pretreatment techniques in order to enhance insensitiveness to impurities were tested with their keeping the high absorption capacity. The three surface pretreatment techniques are (1) alkali pretreatment, (2) pd depositing (3) Cu depositing. In 1998 we comparatively investigated the surface pretreatment to the ZrィイD22ィエD2Fe getter, and its hydrogenating rate after the alkali pretreatment was enhanced about ten times faster than that of the non-treated getter. It was found that pretreated ZrィイD22ィエD2Fe particles under the room temperature can absorb tritium less than the detection limit. In 1999, methane and tritium water vapor cracking by a Zr(MnィイD20.5ィエD2FeィイD20.5ィエD2)ィイD22ィエD2 bed was experimentally investigated. Methane at higher than 650ィイD1゜ィエD1C and water vapor at 350ィイD1゜ィエD1C were successfully cracked by the Zr(MnィイD20.5ィエD2FeィイD20.5ィエD2)ィイD22ィエD2 bed. Results obtained in the present study have been presented at the international symposium of the fusion nuclear technology and that of the hydrogen energy and have been also reported to international journals.