Abstract: The lining structure of the present invention comprises lining plates each having supporting portions formed at two opposite sides of a square lining plate body via bent step portions, and covering portions formed at the remaining sides of the lining plate body; the lining plates being arranged in longitudinal and transverse directions on a surface to be lined; in the first and second lining plates that are adjacent to each other in longitudinal and transverse directions, a covering portion of one of the lining plates being superposed on a supporting portion of, and being butted against the lining plate body of, another of the lining plates, with the butted portion being joined by welding, with an adhesive, or a combination thereof.

Abstract: The invention provides a composite from which concrete featuring a sufficiently high heat resistance can be produced, as well as a high-safety sealed concrete cask having no opening (shielding defect) to offer high shielding performance that can prevent corrosion of an internal canister and release of radioactive material to the exterior. A concrete cask of the invention includes a cask body having a bottom but no lid in itself, and a lid which can open and close off a top opening of the cask body. Both the cask body and the lid are made of concrete manufactured by using a composite including Portland cement or blended cement containing Portland cement, which is mixed with water in such a manner that the content of calcium hydroxide falls in a range of 15% to 60% by mass after hardening through hydration reaction. Metallic heat-transfer fins are embedded in the cask body.

Abstract: It is an object of the present invention to obtain a containment concrete cask which has heat removal capacity maintained at the conventional level or beyond it and which prevents radiation from leaking to the outside. In a concrete cask, a shielding body composed of concrete and heat transfer fins made from metal are provided between an inner shell and an outer shell made from metal, and an accommodation portion for accommodating a radioactive substance is provided inside the inner shell. The accommodation portion has a containment structure to be insulated from the outside of the cask. In the heat transfer fins, the portions thereof at the outer shellside are provided in contact with the outer shell and the portions thereof at the inner shell side are cut so as to form a separation portion with respect to the inner shell.

Abstract: It is an object of the present invention to obtain a containment concrete cask which has heat removal capacity maintained at the conventional level or beyond it and which prevents radiation from leaking to the outside. In a concrete cask, a shielding body composed of concrete and heat transfer fins made from metal are provided between an inner shell and an outer shell made from metal, and an accommodation portion for accommodating a radioactive substance is provided inside the inner shell. The accommodation portion has a containment structure to be insulated from the outside of the cask. In the heat transfer fins, the portions thereof at the outer shellside are provided in contact with the outer shell and the portions thereof at the inner shell side are cut so as to form a separation portion with respect to the inner shell.

Abstract: The invention provides a composite from which concrete featuring a sufficiently high heat resistance can be produced, as well as a high-safety sealed concrete cask having no opening (shielding defect) to offer high shielding performance that can prevent corrosion of an internal canister and release of radioactive material to the exterior. A concrete cask of the invention includes a cask body having a bottom but no lid in itself, and a lid which can open and close off a top opening of the cask body. Both the cask body and the lid are made of concrete manufactured by using a composite including Portland cement or blended cement containing Portland cement, which is mixed with water in such a manner that the content of calcium hydroxide falls in a range of 15% to 60% by mass after hardening through hydration reaction. Metallic heat-transfer fins are embedded in the cask body.