Mitsubishi Heavy Industries Limited

Etsuryo Kita

Kenichi Matsunaga

Koichi Ue

Shizuo Inoue

Kazuo Murakami

Takashi Shige

Ganji Abe

Tsuneo Mandai

Koji Enami

Genji Abe

Seiichi Wakayama

A primary lid is set in a top opening of a vessel body that contains radioactive substance, and closes the top opening. The peripheral edge portion of the primary lid is welded to the inner peripheral surface of the vessel body. As the primary lid is welded, steam in the vessel body is discharged to the outside through a discharge hole in the primary lid, and a shield gas is filled into or run through a space in the outer peripheral portion of the primary lid, so as to prevent the steam from flowing into the welding portion.

Closed vessel for radioactive substance, seal-welding method for closed vessel, and exhaust system used for seal-welding method

A canister containing spent fuel assemblies is contained in a body of a transportation cask. A top opening of a vessel body of the canister is closed by a lid welded to the vessel body. A ring-shaped elastic tube is provided between the inner surface of the upper end portion of the body and the outer surface of the upper end portion of the vessel body. The tube seals the gap between these surfaces to prevent a fluid from getting into the gap between the surfaces through the top opening of the body. An inspection space for the insertion of a tester for detecting the welding state of the lid is defined between the inner surface of the upper end portion of the body and the outer surface of the upper end portion of the vessel body.

Transportation vessel for radioactive substance and method of loading closed vessel

Growing community of inventors

Kobe, Japan

Etsuryo Kita