One way of looking at the drama that has unfolded around the Fukushima Daiichi nuclear reactors is as a narrative with one central plot, and a number of sub-plots distracting the attention. The main story is well established. At 14:46 local time on 11 March, a magnitude 9 earthquake struck off Japan's north-east coast. The 11 operating nuclear power reactors in the region all "tripped" as designed