Diaphragm floor seal bellows for nuclear reactor containers

Purpose: To elongate the life of seal bellows by welding, in combination, horizontally extensible metal bellows and vertically extensible metal bellows to the diaphragm floor separating the dry well and the pressure suppression chamber in bwr type reactors. Constitution: First metal bellows of an U-shaped section whose both ends are bent outwardly is welded to the mounting bed attached to the container. Second metal bellows whose one end extends linearly and the other end is bent at its top are welded to the welding stand on the diaphragm floor steel plate. Since the welding bed is attached to the entire circumference of the steel plate, complete seal can be attained by the above two metal seals. The two metal seals can absorb the contraction and extension both in vertical and horizontal directions thus absorbing heat expansion in any direction. The use of the metal bellows can elongate the life of the seal and improve the reliability. (Moriyama, K.)