Fabrication of oxide fuel elements by rotary swaging

摘要

926,136. Fuel elements. BABCOCK & WILCOX CO. May 27, 1959 [May 27, 1958], No. 18113/59. Class 39 (4). A method of making rod-shaped fuel elements of a given size and density comprises taking a tubular sheath which is shorter and thicker than the given size, filling it with powdered or granular material, e.g. UO 2 , partially compacting the filling, sealing the tube, and mechanically working the tube until it reaches the desired dimensions; the weight of filling is such that when the tube has the desired size, the filling has the desired density. The sheath may be of stainless steel br Al or Zr alloy. Fig. 3 shows a partly made fuel element. One end of a tube 2 is sealed with a thimble-shaped piece 4, welded at 8, and the tube is filled with UO 2 ; the tube is put in a vibrator during filling so that the powdered UO 2 is shaken down to a density of 7.2 gms./c.c., with the help of a tamper. A second closure 4SP1/SP is added and the tube is worked in a rotary swaging machine to reduce the diameter by one third. The ends of the tube are swaged down to give the fuel element shown in Fig. 5. After swaging the UO 2 has a density of about 9.4 gms. per cc. and is in intimate contact with the inside of the sheath.