All control to the video trolley was lost during remote photographing of components in the cyclotron. The control system and cameras on the trolley were still operational leading to the suspicion that a power cable was broken either on the trolley or the bridge festooning. Two trips into the tank were made to evaluate the problem and attempt to push the trolley out of the tank. Pushing the trolley only managed to move the trolley a few feet before jamming. A lift mechanism was used to raise the drive wheel without any success. This device was modified and used successfully to remove trolley completely from the tank.
Three trips by two persons were required to remove the trolley. There was a total dose of 0.5 mSv was received by the two persons going into the tank. An additional 0.18mSv was receive by 3 persons outside of the tank.
The trolley will not be used in the cyclotron until the problem is diagnosed and repaired. This trolley is not critical to any upcoming remote handling operations. |