1983 年 18 巻 4 号 p. 345-351
Comparison of tritiated water leak rate into air and water from hydrates of calcined plaster or molecular sieve which used as fixation materials for waste storage was made. The results were as follows; (1) The leak ratio of tritiated water varied with square root of time when the specimen were in water, but it varied linearly with time when they were in air. (2) The tritiated water leak rate into air was smaller than that into water; for example, 1/100 in hydrates of calcined plaster or 1/6, 000 in molecular sieve adsorbent, comparing the time to reach at 50% of leaked tritium fraction. (3) The fixation materials which show good containment of tritiated water in water leak test were also good in air leak test. (4) The leak rate was reduced by use of the coating of adsorbent with methylmethacrylate polymer or in low humidified air. Furthermore, we discussed the difference of mechanism between leakages into water and air, and finally the amount of tritiated water leaked from a hydrates of 200 litre drum can size for extended period was estimated.