I believe that complex systems fail in simple ways.
The power went out. A simple thing taking out a rather complex set of devices designed exclusively to provide simple power to maintain each piece of the complex system..
Most systemic failures require three things to simultaneously occur. This one seems to be...
1. Earthquake
2. Power goes down
3. Backup pump systems run out of battery power
Simple, not complex.
Even simpler, ...not just one quake, but a series of over 24 quakes within 24 hrs all over 6.0. 30 such quakes within a week and 3 of them over 7.0, with a 10m tsunami thrown in for grins and giggles.
I suspect the place has numerous problems and likely that even if a nuke sub sat adjacent the site, they might still not be able to get power to the circuits requiring the power.
I wonder many conduits and duct banks have been severed in the plant just from seismic activity. If Japan shifted 8 ft, just imagine how much displacement is likely to have happened within the confines of the plants.
By looking at the quake websites, the entire region off the coast in a 100mi radius appears unstable.
8.9-magnitude earthquakes and tsunamis are profoundly disruptive events so it is easy to understand how this failure came about.
A more interesting example might involve autonomous, interconnected systems that magnify the effect of a few minor screwups:
http://en.wikipedia.org/wiki/Northeast_Blackout_of_2003#Findings
One wouldn’t normally expect a couple of untrimmed trees in the middle of nowhere to take out power to the entire eastern U.S.
A chain is only as strong as its weakest link.
Tsunami took out the backup systems, not the earthquake. Flooded the whole area where these plants are located. It was a one-two punch.
Tsunami took out the backup systems, not the earthquake. Flooded the whole area where these plants are located. It was a one-two punch.