Thermonuclear device

Purpose: To reduce the releasing probability of tritium to the circumstances. Constitution: A cryogenic pump and a cryogenic pump containing vessel are disposed in a bell jar and pipeways communicating from the cryogenic pump containing vessel to a fuel purifying system penetrate the bell jar. In a thermonuclear reactor having thus been constituted, if the cryogenic pump containing vessel should be destructed by an accident, the bell jar forms a barrier for preventing the radioactive substance tritium from diffusion. The barrier has a triplet structure comprising the cryogenic pump containing vessel, the bell jar and the building, by which the safety can be improved more as compared with the conventional dual structure. (Yoshihara, H.)