Maanshan 2 shutdown during Taiwan quake

11 January 2007

A series of earthquakes, including one of magnitude 7.1 shook Taiwan on 26 December. One of the island's six power reactors was shut down due to the vibrations.

The epicentre of the seismic activity was 10 km under the seabed, off the island's southern tip. Maanshan 2, a 951 MWe pressurized water reactor in the far south was manually shut down by operators when high vibration alarms sounded on coolant pumps and turbine generators. Maanshan 1 operated normally during and after the accident as did the boiling water reactor units at Chinshan and Kuosheng.

Taiwan's Atomic Energy Council told NucNet that ground acceleration near Maanshan was 0.17 g while the Maanshan reactor units were equipped with systems to safely shut down the reactors up to 0.2 g. Initial inspections showed no damage, but company spokemen said Maanshan 2 would be inspected in detail before electricity generation would resume, and that would probably happen today.

In addition to two deaths, some building collapses and fires, Taiwan suffered suspension of operation at an oil refinery and a silicon wafer factory as well as damage to undersea telecommunication cables.

On 21 September 1999, a magnitude 7.3 earthquake in the centre of Taiwan caused three reactors at Chinshan and Kuosheng in the north of the island to shut down automatically. They were cleared to restart two days later. A fourth reactor there was being refuelled. The two reactors at Maanshan continued operating, but reduced power later due to damage to electricity distribution facilities.

Further information


Atomic Energy Council

WNA's Nuclear power plants and earthquakes information paper