Fluid-tight seal

Herein disclosed is a novel fluid-tight seal suitable for use in the gap between the inner wall of a reactor vessel and an attached suspension drum to eliminate leakage of lower temperature liquid sodium from the gap. The seal consists of a bellows one end of which is fixed to the suspension drum while the other is supported through a spring by a plate fixed to the drum so that the bellows is maintained in a pressed state between the inner wall of the vessel and the outer wall of the drum. A groove is provided over entire periphery of each ridge of the bellows and small holes are drilled through each grooved portion. A negligibly small amount of the lower temperature liquid sodium leaks through the grooves and holes, eliminating self-deposition of the liquid sodium on the bellows wall and reducing wear of the bellow ridges. (Ohno, Y.)