Production of fusion reactor fuel tritium and its chemistry

In D-T nuclear fusion reactors, the feasibility of which seems to be the highest, the isotopes of hydrogen, deuterium and tritium, are used as the fuel. Deuterium exists in large quantity in seawater, therefore its resource does not become a problem, and the techniques of supply have been established. But tritium is a radioactive isotope, and does not exist in nature. It is necessary to produce tritium in a large quantity in order to use it as fuel. The production of tritium was started in USA, USSR and France in 1950s, and it is estimated that more than 0.4 EBq (107 Ci) of tritium has already been produced yearly. In Japan Atomic Energy Research Institute, the research on tritium production was started about 10 years ago as a part of the research on fusion reactor development. Recently, the production test at 3.7 TBq (100 Ci) level has been completed, and the test on 37 TBq scale is in progress. The confimation of process and safety evaluation by gradually increasing tritium quantity, the safe handling techniques to prevent the leak of tritium and the chemistry of tritium are the important subject. The research in JAERI is reported. (Kako, I.)