GB1273977A - Nuclear reactor charge/discharge arrangement - Google Patents

Abstract

1,273,977. Fuelling reactors. BRITISH NUCLEAR DESIGN & CONSTRUCTION Ltd. 17 June, 1969 [4 July, 1968], No. 31972/68. Heading G6C. A reactor comprises a core formed of vertical columns made of moderator blocks, coolant fluid flowing through channels in the blocks in which fuel elements are supported. The columns are arranged in juxta-posed groups on, e.g., a triangular lattice and each group is associated with a centrally-disposed standpipe. In a fuelling arrangement for such a reactor an entire column is transferred through the associated standpipe. As shown in the drawing the columns are of hexagonal cross-section (Fig. 1, not shown) and each group comprises a centre column 1, receiving a control rod, surrounded by six columns 3 receiving fuel elements. Fig. 2 shows a standpipe 7 (from which a closure plug has been removed) and a fuelling device has been lowered through the standpipe so that a locating peg 29 seats in a channel 2 in the centre column 1. The fuelling device comprises a support tube 9 which may receive a guide tube 11, the latter having a hexagonal cross-section and being of such length as to accommodate an entire column. Links 12 connect the tubes 9, 11 and the tube 11 may be moved through an opening 28 in the side of the tube 9 to the displaced position, shown, in which it is aligned with a column 3. The particular column 3 is selected by rotating the device. Lateral displacement of the tube 11 is controlled by a link 26 connected to an actuator rod 27 movable in a guide 25 fixed to the tube 9. This lateral displacement is arrested by the chamfered lower end 19 of the tube 11 engaging the upper ends of those columns immediately adjacent the selected column and this engagement causes the adjacent columns to be urged away from the selected column to facilitate its removal. The fuelling device also includes a cable 13 extending from a winding drum (not shown) over pulleys 14, 15 to a plate-like member 16 slidable within the tube 11, the member 16 carrying a probe 17 having at its bottom end a latching device 21. The lower end of the probe 17 is guided by a plate-like member 18 slidable in the tube 11. The probe 17 is lowered by the cable 13 through a central channel 6 in the selected column 3 and the device 21 is operated to engage the lower end of the column. The cable is rewound and the column 3 is raised into the tube 11, this action lifting the member 18 against the member 16. The tube 11 is withdrawn into the tube 9 and the fuelling device is lifted through the standpipe 7. Holes 22, 23, 24 permit flow of the coolant fluid during the fuelling operation.