GB1064820A - Handling machine for nuclear reactors - Google Patents

Abstract

1,064,820. Fuelling and servicing reactors. ELECTRICITE DE FRANCE. Dec. 18, 1963 [Dec. 20, 1962], No. 50025/63. Heading G6C. A fuelling and servicing machine is movable by a transporter (not shown) over a reactor so that a main conduit 1 may be connected by a bellows seal 3 to a selected standpipe 2 upon the lowering of a shielding section 11a by jacks 34. Similarly, by lowering the section 11a an auxiliary conduit 18 may be connected at its lower end 15 to a tube (not shown) leading to a store for spent or new fuel elements. The lower part of the machine enclosed by shielding sections 11a ... 11e is disconnectible by bolts from the main part enclosed by sections 59a ... 59j so that should the machine fail whilst coupled to a standpipe the main part may be removed after closing a valve 35 in the conduit 1. A main pressure vessel 50a, 50b, 50c pressurized with gas at the reactor pressure has a bottom plate 51 with openings 52, 53 aligned with the conduits 18, 1. The top plate 54 of the pressure vessel has openings 55, 57 giving access to removable auxiliary pressure vessels 56, 58, respectively, this access being controlled by valves 71, 72. A main magazine 61 within the main pressure vessel is suspended by a bearing 81 from the top plate 54 and guided at the lower end in the plate 51 by a bearing 83. The magazine 61 has compartments A ... F which may be aligned with the conduit 1 and housing these components; compartment A- spent plug stringer; compartment B-control rod guide tube; compartment C-emergeney servicing canister; compartment D-charge shoot or one new control rod and one spent control rod; compartment E - new plug stringer; compartment F-fuel element guide tube, when the latter tube is lowered compartment F then serves for discharging the fuel element channels of the reactor. A magazine 62 surrounding the lower part of magazine 61 is supported by a bearing 96 on the plate 51 and has twenty-four chambers 63 which may be aligned with the conduit 18 and each receiving a removable canister for containing fuel elements. A fuel element grab 67 is movable about an eccentric vertical axis 100 by a unit 65 so that it may be aligned either with the compartment F or with a chamber 63. The pressure vessel 56 contains a main hoist 129 controlling a main grab 132, this grab lifting the charge shoot, plug stringer, control rod guide tube and seal plugs of fuel element storage facilities. An auxiliary grab 133, also in the vessel 56 and controlled by an auxiliary hoist 134, is movable transversely out of the way of the main grab 132 and serves to lift the control rods and associated gear and fuel element guide tube. The pressure vessel 58 contains a hoist 157 for controlling a grab 70 for lifting the fuel element canister. In a fuelling operation, after coupling the machine to a standpipe 2 the grabs 132, 133 are used to remove certain components from the standpipe and place them in empty compartments of the magazine 61 and to lower various components from other compartments of the magazine 61 in preparation for the transfer of the fuel elements. The fuel element grab 67 now lifts the spent fuel elements through the magazine compartment F and is moved transversely by the unit 65 to deposit the fuel elements in the canisters in chambers 63. In order to remove the spent fuel elements from the machine the latter is moved so that the conduit 18 may be coupled to a spent fuel store and the grab 70 in the vessel 58 is lowered through a fixed guide tube 64 to lower the canisters from the chambers 63 through the conduit 18. The Specification also describes the procedure for the removal of a burst fuel element and the renewal of a control rod. The machine is cooled by gas circulated under pressure by a turbo-blower. In the event of a fault in a fuel element channel of the reactor preventing discharge of that channel the auxiliary pressure vessel 56 is removed and replaced by an emergency servicing flask containing a T.V. camera and special tools. Further, the auxiliary pressure vessel 58 may be replaced by a sealed flask containing a grab in the event of a fault in the machine.