Speaker
Takahito Maruyama
(Department of ITER Project)
Description
How to recover from failures of components in radiation environment is an important issue of the ITER remote handling systems. Recovery operations of the remote handling systems must be performed remotely due to limitation of human access. For the ITER Blanket Remote Handling system, failure modes have been analysed, and the analysis has concluded that electrical failures of actuators, which are motors and resolver position-sensors, are need to be recovered and likely to happen. Those failures will be caused by insulation deterioration by radiation and failures of electrical connectors. To make the ITER Blanket Remote handling System recoverable from those failures, we developed two recovery methods, and this paper presents them.
The first method is rescue operation using manipulators. The failed actuator can be driven by external force because it is not damaged mechanically in the considered situation. We designed a rescue tool to drive the failed actuator externally and rescue manipulators to handle it. In addition, we studied reach of the rescue manipulators and concluded that the ITER Blanket Remote Handling System can be recoverable using the rescue tool and manipulators. The second method is applicable for resolver failures: connecting another resolver (hereafter called ‘dummy resolver’) to the motor driver instead of the failed resolver. Then the driver regards positon of the dummy resolver as the current position of the motor. By controlling the driver to keep ‘the current positon’, the driver tries to keep the motor positon same as dummy resolver. Thus, the motor with the failed resolver can be driven by rotating the dummy resolver. We tested and confirmed that the motor follows rotation of the dummy resolver under load up to the rated torque by the rated rotation speed, and concluded this method is applicable to the ITER Blanket Remote Handling System.
Co-authors
Masafumi Komai
(Department of ITER Project, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Nobukazu Takeda
(Department of ITER Project, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Satoshi Kakudate
(Department of ITER Project, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Takahito Maruyama
(Department of ITER Project, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
Yuto Noguchi
(Department of ITER Project, Japan Atomic Energy Agency, Naka-shi, Ibaraki-ken, Japan)
