Abstract: A sealable metal multipurpose canister for confining irradiated nuclear fuel assemblies and a sealing means therefor. The canister includes a tubular or cylindrical body having a vertical major axis and vertical wall, a lower end closed by a welded base and an open and sealable upper end having a vertical inner wall section including a transverse shoulder extending over at least a portion of the vertical inner wall. The sealing means includes a first solid metal sealing disk supported by the transverse shoulder and having a peripheral portion cooperating sealingly with the vertical inner wall, a second solid metal sealing disk resting on and above the first sealing disk and having a peripheral portion cooperating sealingly with the vertical inner wall and a gripping means located inside the upper end above the second sealing disk, and acting on the first and second sealing disks to create a leaktight seal.