Source: MSNBC
When Japan experienced an earthquake of magnitude 8.9 on March 11, its nuclear reactors at the Daiichi plant in Fukushima automatically shut down, as it was designed to. However, the earthquake and subsequent tsunami were more devastating than the reactors were built to withstand. Water pumps designed to cool the fuel rods in the reactor cores were supposed to be supplied with external power lines, with a back-up of diesel generators. Both of these mechanisms were wiped out by the earthquake and tsunami. Speaking on MSNBC’s Andrea Mitchell Reports, Carnegie’s James Acton explained that reactor cores as well as spent fuel rods, which are stored in water pools adjacent to the reactors, remained hot. The water in those pools must be replaced and recirculated so that it does not overheat, exposing the spent fuel and thereby releasing radiation, Acton said. He emphasizes that reactors can weather disasters that they are designed to survive. Accordingly, this crisis should prompt a reevaluation of the magnitude of earthquakes, floods, tornadoes, and other hazards reactors could face.