HANARO, an open-tank-in-pool type research reactor of 30 ㎿th power in Korea, which is different from a power plant reactor, exhausts a fission heat generated from the reactor core into the atmosphere through a secondary cooling tower instead of an e...
HANARO, an open-tank-in-pool type research reactor of 30 ㎿th power in Korea, which is different from a power plant reactor, exhausts a fission heat generated from the reactor core into the atmosphere through a secondary cooling tower instead of an electric power production from the heat. During every one month inspection of the cooling tower, a No. 4 cooling fan gear reducer of the cooling tower recoded a high unstable vibration above the limit. To find the reason, a frequency analysis was conducted. It was conformed through the results of the frequency analysis that the frequency of the high vibration was 354 ㎐ which was calculated two times rotation of the pinion gear of the gear reducer. There was a broken of the gear surface of the pinion gear transferred the rotation power. After the repair of the pinion gear, the reducer was operated normally.