MANUFACTURING METHOD OF RADIOACTIVE MATERIAL CONTAINMENT VESSEL

摘要

PROBLEM TO BE SOLVED: To provide a radioactive material containment vessel requiring little labor hour for manufacturing. SOLUTION: A metal billet 202 used for hot expansion molding comprises an upper rim 202a and a lower rim 202b on both ends, and the sectional shape thereof is substantially the same as the inside sectional shape of a molding container 300. The lower rim 202b in a pressing forward side has a taper 205 so that the outer shape is minimized toward the pressing direction. The middle part of the metal billet 202 is formed so that the sectional area corresponds to the difference between the inside sectional area of the molding container 300 and the sectional area of a boring punch 400. After the metal billet 202 is inserted to the molding container 300, the billet 202 is hot expansion-molded by the boring punch 400.