Japan earthquake shuts nuclear facilities

However, as yet there has been no reported leakage of radiation from any of the reactors and at this stage experts are not predicting any major discharge that would be hazardous to human health.

According to the International Atomic Energy Agency (IAEA) the Fukushima Daiichi, Fukushima Daini, Tokai and Onagawa nuclear power stations all automatically shut down soon after the 8.8 magnitude quake hit at 2.45pm local time. A fire broke out in the turbine building of the Onagawa plant while the Fukushima Daiichi plant reported problems with its cooling system.

Nuclear power plants have a series of strategically-placed sensors that detect peak ground acceleration (PGA) — which describes surface movement at particular places, rather than the cruder measure of the magnitude of the earthquake itself. Over a certain PGA threshold the sensors will trigger an automatic shutdown of the reactors.

‘Although this earthquake was massive, it was some way off-shore and the levels of shaking on land should not have been as high as in 2007, where the earthquake was smaller in magnitude but directly below the nuclear plant itself,’ said Julian Bommer, Professor of earthquake risk assessment at Imperial College London.