Method of preparing hollow type

Claim 1

A METHOD OF MAKING AMETALLIC CLAD NUCLEAR REACTOR FUEL ELEMENT COMPRISING, PROVIDING A GIVEN QUANTITIY OF NUCLEAR REACTOR FUEL MATERIAL, CONFINING SAID FUEL MATERIAL IN AN ELONGATED CYLINDRICAL TUBULAR METALLIC SHEATH HAVING AN OUTER SHEATH PORTION AN DINNER COAXIAL SHEATH PORTION DEFINING AN AXIALLY EXTENDING BORE THERETHROUGH AND A TUBULAR SPACE BETWEEN SAID PORTIONS WITH ONE END OPEN AND AN OPPOSITE END CLOSED, INSERTING A MANDREL THROUGH SAID BORE THE FULL LENGTH THEREOF AND FITTING SNUGLY THEREIN, SAID MANDREL HAVING AN ELASTIC MODULUS OF AT LEAST 5X10**3 KG./MM.2, AND A YIELD POINT OF NOT LESS THAN 5 KG./MM.2 AND HAVING A MELTING POINT LESS THAN THE MELTING POINT OF SAID INNER AND OUTER PORTIONS OF SAID METALLIC SHEATH, SUBJECTING THE TUBULAR SHEATH TO ROTARY SWAGING TO REDUCE THE OUTER DIAMETER OF SAID SHEATH AND COMPRESS SAID OUTER SHEATH PORTION RADIALLY INWARDLY WHILE PERMITTING ELONGATION THEREOF THEREBY TO COMPACT AND DENSIFY NUCLEAR REACTOR FUEL MATERIAL IN SAID SPACE WITHOUT REDUCTION OF THE DIAMETER AND SAID BORE, MELTING SAID MANDREL AND REMOVING THE MELTED MANDREL FROM SAID BORE, BEFORE BEGINNING SAID ROTARY SWAGING FILLING SAID TUBULAR SPACE WITH NUCLEAR REACTOR FUEL MATERIAL AND CONFINING IT THEREIN, REMOVING THE OPPOSITE END PORTIONS OF SAID COAXIAL SHEATH PORTIONS, AND SUBSEQUENTLY SEALING THE ENDS OF THE REMAINING METALLIC SHEATH TUBULAR SPACE FILLED WITH DENSE COMPACTED FUEL MATERIAL THEREBY SEALING SAID FUEL MATERIAL THEREIN.

Claim 2

A METHOD OF MAKING AMETALLIC CLAD NUCLEAR REACTOR FUEL ELEMENT COMPRISING, PROVIDING A GIVEN QUANTITIY OF NUCLEAR REACTOR FUEL MATERIAL, CONFINING SAID FUEL MATERIAL IN AN ELONGATED CYLINDRICAL TUBULAR METALLIC SHEATH HAVING AN OUTER SHEATH PORTION AN DINNER COAXIAL SHEATH PORTION DEFINING AN AXIALLY EXTENDING BORE THERETHROUGH AND A TUBULAR SPACE BETWEEN SAID PORTIONS WITH ONE END OPEN AND AN OPPOSITE END CLOSED, INSERTING A MANDREL THROUGH SAID BORE THE FULL LENGTH THEREOF AND FITTING SNUGLY THEREIN, SAID MANDREL HAVING AN ELASTIC MODULUS OF AT LEAST 5X10**3 KG./MM.2, AND A YIELD POINT OF NOT LESS THAN 5 KG./MM.2 AND HAVING A MELTING POINT LESS THAN THE MELTING POINT OF SAID INNER AND OUTER PORTIONS OF SAID METALLIC SHEATH, SUBJECTING THE TUBULAR SHEATH TO ROTARY SWAGING TO REDUCE THE OUTER DIAMETER OF SAID SHEATH AND COMPRESS SAID OUTER SHEATH PORTION RADIALLY INWARDLY WHILE PERMITTING ELONGATION THEREOF THEREBY TO COMPACT AND DENSIFY NUCLEAR REACTOR FUEL MATERIAL IN SAID SPACE WITHOUT REDUCTION OF THE DIAMETER AND SAID BORE, MELTING SAID MANDREL AND REMOVING THE MELTED MANDREL FROM SAID BORE, BEFORE BEGINNING SAID ROTARY SWAGING FILLING SAID TUBULAR SPACE WITH NUCLEAR REACTOR FUEL MATERIAL AND CONFINING IT THEREIN, REMOVING THE OPPOSITE END PORTIONS OF SAID COAXIAL SHEATH PORTIONS, AND SUBSEQUENTLY SEALING THE ENDS OF THE REMAINING METALLIC SHEATH TUBULAR SPACE FILLED WITH DENSE COMPACTED FUEL MATERIAL THEREBY SEALING SAID FUEL MATERIAL THEREIN.