Method of fabricating fuel elements which are shielded and sheathed fuel elements obtained by this process

摘要

816,919. Making nuclear fuel elements; welding by pressure. ATOMIC ENERGY OF CANADA Ltd. April 1, 1957 [May 18, 1956], No. 10573/57. Classes 83 (2) and 83 (4). [Also in Group XL (a)] In making a nuclear fuel element a bar 1 of fissile fuel, e.g. uranium, enriched uranium, &c., is assembled in an aluminium sheath 2 closed at an end by an aluminium plug 3, the assembly is mounted in die means 6 supporting the sheath, and the plug and the sheath in the vicinity of the plug are heated to a temperature below the melting point of aluminium and a high pressure is exerted at least on the outer end of the plug to effect bonding of the plug and sheath. The rectangular section bar 1 and plug 3 at each end thereof are assembled with dovetail connections 4 in the sheath which has reactor mounting projections 5 and the sheath may be pressed on to the bar. The assembly is placed between die blocks 6 with the surfaces of the blocks, plug and sheath coplanar and the blocks are heated to heat the joint to approx. 500‹ F., 800-900‹ F. or approx. 1200‹ F. A ram 7 exerts a pressure of 15,000-20,000 pounds per square inch or approx. 31,000-32,000 pounds per square inch for about 15 seconds to effect bonding. It is stated to be known to employ a helium shielded arc welding electrode and aluminium filler rod to weld aluminium plugs to the ends of aluminium sheathed fuel rods.