STUDY ON A NEW ARRANGEMENT FOR THE AIR CLEANUP SYSTEM TO RECOVER TRITIUM

目前，负责从室内空气中紧急回收氚的空气净化系统的标准安排是一个带加热器的催化氧化床，然后是一个带冷却器的吸收床。这种安排的一个缺点是加热器或冷却器的故障可能导致回收氚的能力丧失。催化吸附床布置的另一个缺点是，氚化水在工作气氛中经过大量水蒸气稀释后，必须以高去污系数回收。本文提出了一种新型的空气净化系统布置方案，该方案由贵金属催化剂床和不带设备的吸附床组成。根据计算，当采用新布置时，释放到室内空气中的氚大部分通过氧化、吸附和同位素交换反应在催化剂床上回收。放置在催化剂床之前的吸附床对工艺气体进行除湿，使催化剂床中氚的氧化反应不受室内水蒸气的阻碍。在一个小型模型反应堆室内进行的实验中，新的布置可以从室内空气中回收氚，并达到预期的性能。

At present, the standard arrangement of the air cleanup system responsible for emergency tritium recovery from room air is a catalytic oxidation bed with a heater followed by an absorption bed with a cooler. One disadvantage of this arrangement is that trouble with the heater or the cooler could result in a loss of capacity to recover tritium. Another disadvantage of the catalyst-adsorption bed arrangement is that tritiated water must be recovered with a high decontamination factor after dilution with a large amount of water vapor in the working atmosphere.The performance of a new arrangement for the air cleanup system, which consists of a precious metal catalyst bed preceded by an adsorption bed without equipment , is proposed in this research project. According to calculations, most of the tritium released to the room air is recovered in the catalyst bed through oxidation, adsorption, and isotope exchange reaction when the new arrangement is applied. The adsorption bed placed before the catalyst bed dehumidifies the process gas to such a degree that the oxidation reaction of tritium in the catalyst bed is not hindered by water vapor in room.The new arrangement could recover tritium from the room air with the expected performance in the experiment using an small scale model reactor room.