Method for sealing a metallic cask for shipping and/or long-term storage of radioactive materials, and cask closed using the method

摘要

In a method for sealing a metallic cask (1) for shipping and/or long-term storage of radioactive materials which has a metallic sealing cover (4), in which the sealing cover is welded to the cask, the aim is to construct the welded joint without a separate thermal source for heating the joining surfaces at the cask and sealing cover to the melting temperature. According to the invention, the sealing cover (4) is welded to the cask (1) by the thermometallic reaction of a powder (P) which is introduced into a melting space bounded at least partially by the cover and cask and containing at least one metal oxide and a reducing agent. It is preferred to use a separate melting mould (6) for the smelting after the sealing cover has been mounted. It is also expedient for the welding seam boundary surfaces (1a, 4a) of the cask to enclose at the base of the welding seam an angle of alpha /= 45 DEG with respect to a plane (E) perpendicular to the direction of the longitudinal extent of the cask, which essentially excludes the adhesion of slag particles to the joint surfaces. The application also relates to a cask which is sealed using the method according to the invention. IMAGE