Hitachi, Ltd.

Hitachi-ge Nuclear Energy, Ltd.

Kunihiko Iwama

Yutaka Kometani

Yoshiaki Ichikawa

Tomiharu Yoshida

Yuji Hosoda

Kenji Tsuchita

Makoto Senoh

Akira Koizumi

Yutaka Arai

Ryoji Azumaishi

Fuel exchange apparatus

An automatic refueling apparatus has a travel carriage, a traverse carriage and a fuel assembly grappling apparatus composed of a grapple, an extension pipe and a hoist. The automatic refueling apparatus also includes a system for controlling automatic fuel transferring operations, in which a calculation unit and a control unit are provided. After the positions of a start point and a target terminal point of a fuel assembly transfer are input through an input device, the calculation unit determines the shortest route from the start point to the terminal point in a preset fuel transferring permitted region, and the control unit generates driving command signals for moving the fuel assembly grappling apparatus along the obtained shortest route through a simultaneous control along X, Y, Z (Z: an elevation direction vertical to a X-Y horizontal plane of the grapple) and .theta. (a rotation direction in a X-Y horizontal plane of the grapple) axes.

Automatic refueling apparatus

An automatic nuclear fuel assembly replacing apparatus has a bridge and a trolley movable in X and Y axis directions, respectively. Mounted on the trolley is a nuclear fuel grapple movable in a Z axis direction and rotatable about the Z axis. A television camera mounting unit is also mounted on the trolley and movable in the Z axis direction. A control system of the apparatus moves the bridge and the trolley so that the center of an underwater television camera supported by the camera mounting unit is centered to a desired target position. Then, calculations are performed on the deviations of the position of the thus positioned camera and a target fuel assembly in the X and Y axis directions and about the Z axis, respectively. The thus calculated results are corrected by a deviation between the fuel grapple and the camera, whereby the position of the fuel grapple is finally controlled to be in alignment with the position of the target fuel assembly in the X and Y axis directions and about the Z axis.

Apparatus for automatically replacing nuclear fuel assemblies

A method and an apparatus for controlling a reactor refuelling machine including a plurality of grippers comprised of a plurality of telescopic bars which are telescopically actuatable independently of each other and at least one gripping member mounted to each telescopic bar. A decision is made as to whether the movement of a particular gripper in the Z direction is constrained by a status of the movement of a different gripper. The parallel operation is performed when the movement of the particular gripper in the Z direction is not constrained and when constrained, the particular gripper is placed in condition for waiting.

Method and apparatus for controlling refuelling machine of reactor

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Hitachinaka, Japan

Kunihiko Iwama