Patent GB-874223-A (GB)
Title: Improvements in or relating to apparatus for positioning an adjustable chute such asa fuel element charge chute for a nuclear reactor
Inventor: BELLINGER RONALD
IPC: G21C19/16
Filed: 1956-11-15
Abstract: 874,223. Handling nuclear fuel elements. STRACHAN & HENSHAW Ltd. Nov. 15, 1957 [Nov. 15, 1956], No. 35023/56. Class 39(4). A shoot for charging and discharging fuel element channels in a reactor core comprises an upper part and a lower part pivoted thereto, the shoot being adjusted to serve a selected channel by bodily rotating it and by moving the lower part so that the end of the latter is at a desired radial distance from the axis of the upper part. Such a shoot is disclosed in Specification 874,222. Apparatus for adjusting the shoot comprises, Fig. 1, a housing 2 mounted at the top of a reactor charge tube (not shown) by a flange 4, the housing rotatably supporting by bearings 10 a sleeve 8. Longitudinal splines (Fig. 2, not shown) on the sleeve 8, engage teeth on the shoot head 16, and the top of the sleeve has teeth 20 engaged by a worm whereby the shoot is bodily rotated by rotating the worm. A sleeve 50 mounted on the shoot head 16 at 53 so as to be rotatable thereon but held axially captive thereto has longitudinal gear teeth 60 meshing with a pinion 36 driven by a shaft 46 through gears 42, 44. A toothed bolt 62 slidable in a longitudinal groove 64 in the head 16 co-operates with a sixteen-start thread 58 on the interior of the sleeve 50 whereby operation of the shaft 46 causes vertical movement of a rod 66 coupled to the bolt 62, the rod being connected to the lower part of the shoot and hence the latter is adjusted. The passage through the apparatus may be closed by a pair of valve members 74 having threaded portions engaged by a shaft 78 whereby rotation of the shaft may cause the members to slide towards each other. According to another construction, Figs. 6, 8, the shoot (not shown) may be detached from the headbox and moved therethrough, the headbox 1 containing two double-walled sleeves 2, 3 each independently driven by an electric motor through worm gearing (Figs. 3-5, not shown). A pair of solenoids 4 within each sleeve controls a key 6 so that by energizing the solenoids the keys may be moved to respectively engage the shoot head and the sleeve rotatable thereon and effect a driving connection with the head and sleeve. Bodily rotation of the shoot is accomplished by rotating the sleeves 2 whereas adjustment of the lower part of the shoot is performed by rotation of the sleeve 3. Indicators are provided On the top of the box 1 showing the rotational, position of the shoot and also the radial extent of its lower part, these indications being transmitted for remote indication by a mag slip generator. According to a further construction (Figs. 9, 11) the headbox is intended for connection at its upper end to the underside of a charge machine and has a double-jointed gas-tight spherical coupling comprising a pair of telescopic members 101, 102, the member 102 being housed in a flange 104 which is raised by three CO 2  operated cylinders 109 to engage the charge machine. Bodily rotation of the shoot and adjustment of the shoot lower part are effected, respectively, by rotation of sleeves 115, 116, independently driven through gearing and motors as in the previously described embodiment. Each sleeve has pivoted thereon at 118 a key 117, arms on each key having rollers 119 running in an internal groove in a respective one of a pair of cages 120. The cages are vertically movable by CO 2  operated pistons 123 whereby the keys 117 may be made to engage keyways in the shoot head and the sleeve rotatable thereon. Local and remote indication is provided as in the previous embodiment. Further, as in the previous embodiment the shoot may be withdrawn from the headbox when the keys are in the disengaged position.