Westinghouse Electric Corporation

John W Kaufmann

Leonard P Hornak

Kenneth J Swidwa

Bruce M Cook

David H Ditto

Charles E Meyer

Refueling apparatus for a nuclear reactor including a bridge and a trolley. The bridge is moveable in tracks along the containment of the pit in which the reactor is immersed in water and the trolley moveable in tracks on the bridge at right angles to the tracks on the bridge. The trolley carries a mast assembly for engaging, raising, and lowering a nuclear-reactor component assembly involved in the refueling. The mast includes an elongated member for engaging control-rod and thimble plug assembly and a gripper for raising fuel assemblies. The elongated member is moveable upwardly or downwardly. A TV camera and a light source and reflector are mounted on the gripper assembly at the lower end of the mast assembly. The source and reflector illuminate a selected part of the fuel assembly which is to be transferred and the camera is directed to this part so as to pick up an image of this part. The cooperative TV-receiver monitor on the console on the trolley is provided with cross hairs. The mast assembly is set by aligning the cross hairs with images of the heads of selected bolts on the image of the reactor component assembly.

Television alignment of mast assembly in refueling of nuclear reactor

Refueling apparatus for a nuclear reactor including a bridge and a trolley movable at right angles to each other over a pit. The trolley carries a mast assembly for engaging, raising, lowering reactor component assemblies. The mast assembly carries electric cables and compressed air hoses from electric and air driven components on the mast and is rotatable relative to the trolley. The cables and hoses are passed from the mast assembly through a flexible cable tray which is oriented with its cable-carrying slot vertically in the configuration generally of an S. The cable tray is connected to the mast at one of its ends, is partly wound around the mast from that end and departs from the mast a predetermined distance at the opposite end. The tray remains fixed at the opposite end as it is wound on or unwound from the mast, so that the cables and hoses as they pass from the opposite end to electrical and air terminals as the trolley remains anchored at the opposite end. The winch and the reels for cables and hoses are mounted on the rotatable mast. On rotation of the mast, these reels with the parts that they carry and the air hose are carried along by the rotation. The fouling of the cables or hoses by the conductors is precluded.

Refueling of nuclear reactor

Refueling apparatus for a nuclear reactor including a bridge and a trolley. The bridge is moveable in tracks along the containment of the pit in which the reactor is immersed in water and the trolley moveable in tracks on the bridge at right angles to the tracks on the bridge. The trolley carries a mast assembly for engaging, raising, lowering a nuclear-reactor component assembly involved in refueling. The mast includes an elongated member for engaging control-rod and thimble plug assembly and a gripper for raising fuel assemblies. The elongated member is moveable upwardly or downwardly. The bridge, trolley and mast assembly each has a pulse generator which produces pulses in accordance with the movement of each. The number of pulses produced when the bridge, trolley or elongated member move to a position at a predetermined distance from a reference position is a measure of the new position of each. The mast assembly can be positioned over the reactor at positions whose location can be set in terms of number of pulses as coordinates of a Cartesian coordinate system. The axes of the coordinate system are parallel to the directions of motion of the bridge and trolley. The elongated member likewise can be positioned vertically at a height whose location can be set by a coordinate measured by its number of pulses. As the bridge, trolley or elongated member move, limit switches are actuated by each at a predetermined position in its track. The signal produced by actuation of each switch yields a reading of the position of the bridge, trolley or elongated member at the instant of actuation and this is compared with a computer entry of the position which the vehicle in question should occupy. The computer is programmed to make a compensating correction in the position of the vehicle or elongated member.

A control system for a nuclear reactor is disclosed. A control rod strategy computer provides for dynamic control of core power distribution in both radial and axial directions and forms the basis for a partial trip capability. Several microprocessor-based computation centers are combined together in a data-sharing network which processors determine local power density, determine the instantaneous differential and integral reactivity worth of each group of control rods, determine and effectuate partial trip for immediate power reduction, determine and provide for uniform core burnup, and effectuate core reactivity changes by directing the movement of groups of four control rods from zero to one hundred percent of travel while minimizing power distribution factors throughout the core. The power control circuitry to move the groups of control rods are bus arranged such that the power circuitry is shared among the groups of control rods. In this manner, the power to the control rod drive mechanisms is controlled and bus arranged for distribution to these drive mechanisms. This arrangement allows separate housings or cabinets for each holding circuit for each group of control rods and one housing or cabinet for the moving circuit for all of the groups of control rods.

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Murrysville, PA, United States of America

John W Kaufmann