In the light of the crisis at the Fukushima-Daiichi plant, nuclear regulators worldwide are reassessing the resilience of reactors to natural hazards.
Many reactors in Asia, in particular, are in zones prone to earthquakes, as shown below. Roll over the icons to find out more about each current reactor site.
Source: Global Seismic Hazard Assessment Program/GFZ/US Geological Survey/World Nuclear Association
The map shows earthquakes of magnitude 7.0 and above listed in the US Geological Survey’s catalog, from 1973 to present, plus an assessment of seismic hazards from a United Nations-backed project that completed its work in 1999. Seismologists are now working on an updated assessment, called the Global Earthquake Model, which should be available from late 2013.
However, some researchers argue that seismic hazard mapping, which relies on knowledge of past earthquakes and an assessment of the risks posed by known faults, is at best a flawed science. The Japanese megaquake is just one of several in recent years to have exceeded the magnitude predicted for the regions in which they occurred, critics point out.
One encouraging sign is that shaking from the 2011 magnitude 9.0 quake did not itself seriously damage Japan’s nuclear reactors — it was the tsunami that trigged the Fukushima crisis. Still, unexpectedly large earthquakes could cause problems for some facilities.