GB836562A - Improvements in nuclear reactor fuel element handling plant - Google Patents

Abstract

836,562. Handling materials in radioactive environment. BABCOCK & WILCOX Ltd. April 18, 1957 [April 20, 1956], No. 12127/56. Class 39(4). [Also in Group XXX] Spent rod-like fuel elements are transferred from the top 3 of a concrete reactor housing 2 to a pond 90 by a helical shoot 12X or 12Y into either one of which a fuel element may be dropped from a loading machine 5. The machine 5 is movable on railway tracks 4 to the various element-collections on the top 3 and the filled machine is brought to a desired one of a pair of discharging positions corresponding to the entrances to the shoots. The lower end 12DX of the shoots lie spaced from each other in the same horizontal, or substantially horizontal plane, Fig. 2 (not shown), and each shoot terminates in a discharge chamber 13X. Frictional forces brake the descent of a fuel element so that it would come to rest within the end 12DX; however, the element is driven into the chamber 13X by water jets 48, 49 arranged in upper surface of the shoot. The elements are removed from the discharge chambers in a skip 103 on a hoist carriage 102 running on inclined tracks 101, a transporter crane 120 moving a skip from its carriage to a desired part of the pond 90. Each discharge chamber has its own hoist carriage and the arrangement is as described in Specification 808,381 (see Group XL(a)). The shoots are formed of cast iron twelve inches thick for biological protection and the helical parts are divided into sections about five feet six inches long each section having a thick lid 19. The sections are secured end to end by bolts in lugs 22 and the spaces therebetween caulked with lead and aluminium. Each section may be removed and lifted upwards within the chamber 18 without disturbing adjacent sections and to this end the junctions between adjacent sections are each supported on a single cradle 27 carried by a steel framework 25, 26, Fig. 5 (not shown). Should fuel element prematurely come to rest within the helical part of a shoot it may be dislodged by high pressure water jets provided in alternate shoot sections ; alternatively, cast iron plugs 36 may be removed and pole rods inserted in the holes 35.