Patent GB-1206856-A (GB)
Title: Improvements in and relating to apparatus for removing lugs of nuclear fuel element cans
Inventor: NICOL JAMES MILLER
IPC: G21C19/36
Filed: 1968-07-15
Abstract: 1,206,856. Shearing. BABCOCK & WILCOX Ltd. 6 Oct., 1969 [15 July, 1968], No. 33724/68. Heading B3W. [Also in Division G6] Apparatus for shearing off lugs from a spent nuclear fuel element can, the lugs being situated at intervals along the can length and at four equi-angularly spaced positions around the can surface (Figs. 5, 6, not shown), comprises a pair of trough plates 9 into which the fuel element can is dropped in a horizontal position after being pushed up inclined guide rails 142 by means of thrust blocks 144 driven by an hydraulic cylinder actuator 148. The can is then advanced in a quick stepping motion through the guillotine unit 3 of a cutting head 1 into a trough plate 29. Since the orientation of the can in the trough plates 9 is indeterminate the can is orientated by a block 2 to ensure that the lugs lie in horizontal and vertical planes as they advance through the unit 3, this unit shearing off those lugs lying in the horizontal plane. Before the can is stepped in the return direction from the trough plate 29 to the trough plates 9, it is orientated through 90 degrees by a turning block 4 so that on passage through the unit 3 the remaining lugs are sheared off. The means for traversing the fuel element can through the cutting head 1 comprises a frame 40 running on rails 41, pillars 42, 43 at the ends of the frame having offset arms 44, 45 carrying can pushing means 46, 47. The can is advanced from left to right by the means 46 and from right to left by the means 47, this motion being derived from an hydraulic actuator coupled to the frame 41 so that the latter moves in a quick stepping action. The block 2, Figs. 13-16, comprises a passage 101 therethrough for the can, the entry 105 being of approximately square cross-section with chamfers 107 and the exit 106 being of cruciform cross-section formed by grooves 108 for receiving the can lugs, the width of these grooves tapering towards the exit end. The passage 101 has various shaped surfaces as shown whereby whatever may be the orientation of the can at the entry 105, as the can is advanced from left to right it is caused by the shaped surfaces to rotate so that the lugs lie in the horizontal and vertical planes. Fig. 14 shows the top left-hand quadrant of the block 2, the top right-hand quadrant being similar. Fig. 15 shows the bottom left-hand quadrant and Fig. 16 the bottom right-hand quadrant. The guillotine unit 3, Figs. 11, 12, comprises a lower anvil 71 having fixed cutting edges 72 and vertically movable upper cutting blades 73. A recess 74 accommodates the lower vertical lugs of the can as it passes through the unit whilst the horizontal lugs are guided by ramps 76, 77. The blades 73 are mounted in a holder 85 secured to a plate 83 movable on posts .82 by an hydraulic actuator 92. Pins 89 slidable in the holder 85 are carried by a plate 88 biased by a spring 87 in a recess 86. These pins hold the fuel element can on the anvil 71 under the pressure of the spring 87 during the shearing operation. The turning block 4, Fig. 17, comprises a rotatable member 131 having a cruciform-shaped aperture 134 receiving the vertical lugs of the can, this member being rotated through 90 degrees by an hydraulic actuator connected to the arm 135.