GB1074282A - Improvements relating to charging machines for nuclear reactors - Google Patents

Abstract

1,074,282. Fuelling reactors. FAIREY ENGINEERING Ltd. June 8, 1964 [March 12, 1963], No. 9794/63. Heading G6C. A charge machine 15 movable on a reactor surface 10 to align its charge axis 16 with a selected standpipe includes the features of the machine disclosed in Specification 972,734 and comprises an annular carriage 20 supported by a number of parallel wheels 21 individually driven by motors 26, the carriage being connected through a ring bearing 30 to a pressure vessel 32 containing the charge machinery. The wheels 21 are mounted in yoke frames 22 pivoted at one end 23 to the carriage 20 and are vertically retractible by hydraulic jacks 25 connected to the other ends of the frames. When the jacks 25 are extended the base 35 of the vessel 32 is held clear of the surface 10 whereas when the jacks are retracted the wheels 21 leave the surface 10 and the machine 15 is supported by the base. Relative rotation between the carriage 20 and the vessel 32 is performed by a motor unit 33 on the carriage driving a gear ring 34 on the vessel. The machine may be inched on the surface 10 by disconnecting the wheel drive motors 26 and lowering an inching foot 36 by a twin hydraulic jack 38 connected at its upper end to the carriage 20, the inching motion being imparted by a horizontal jack 40 pivotally connected at one end 41 to the foot and at the other end to a bracket 42 mounted on the carriage, the axis of the jack 40 being perpendicular to the rotational axes of the wheels 21. The mouths of the standpipies are located at the intersections of two sets of parallel grooves 18 and 19 formed at right-angles to one another in the surface 10, Fig. 5, and to facilitate alignment of the charge axis 16 with a selected standpipe, e.g. standpipe 13B, the surface is viewed by one or more T.V. cameras carried by the carriage 20 and producing a picture at a control station 50A or 50B. The control stations are located at diametrically opposite positions on the carriage 20 and are used alternatively depending on the direction of the machine movement, each station having a seat 52A or 52B, a T.V. monitor screen 51A or 51B and a control panel 53A or 53B. As shown, there are five T.V. cameras comprising two outward sighting diametrically opposed cameras W, X adjustable in elevation in a vertical plane perpendicular to the rotational axes of the wheels 21; two inward sighting cameras Y, Z disposed at right-angles to one another and viewing the surface 10 in the vicinity of the axis 16, and a camera V viewing an angular scale 57 of degrees on the pressure vessel 32 to indicate the relative rotational positions of the carriage 20 and the vessel. In order to align the axis 16 with the standpipe 13B the operator uses the control station 50B nearest to the standpipe and switches on the camera W, the wheels 21 are retracted and the carriage 20 is rotated until the wheels point in the direction of the standpipe, the latter being judged by eye until it can be observed by the camera, a flattened elliptical image W<SP>1</SP> of the standpipe being displayed on the screen 51B as shown in Fig. 11. The image is central with respect to a graticule 60 in the camera lens system and thereby indicating that the wheels 21 are pointing towards the standpipe 13B. The wheels are lowered and the machine is driven towards the standpipe, the camera Z being switched on. As shown, as the standpipe image Z<SP>1</SP> appears on the screen, Fig. 12, the motors 26 are stopped and the inching foot 36 is used to centralize the image Z<SP>1</SP> with respect to the camera graticule 61. The image Z<SP>1</SP> lies to the left or right of the graticule 60 depending on the deviation of the machine in its movement towards the standpipe. The camera V is switched on to read the scale 57, the wheels 21 are retracted and the carriage 20 is rotated precisely through 90 degrees by using the scale. The cameras Y, Z are switched on and give images Y<SP>1</SP>, Z<SP>1</SP> displaced relatively to the graticules 61, 60, Fig. 15, the wheels 21 are lowered and the inching foot 36 is used to bring the images to the Fig. 18 position in which the axis 16 is aligned with the standpipe. If desired, the carriage 20 may be orientated relatively to the floor 10 by using the camera X or W to sight the groove 18 extending through the standpipe location and centralizing this groove on the camera graticule.