Washington’s Blog 
May 24, 2011
Bloomberg reported  last week:
A radiation alarm went off at Tokyo Electric Power Co.’s Fukushima nuclear power plant before the tsunami hit on March 11, suggesting that contrary to earlier assumptions the reactors were damaged by the earthquake that spawned the wall of water.
A monitoring post on the perimeter of the plant about 1.5 kilometers (1 mile) from the No. 1 reactor went off at 3:29 p.m., minutes before the station was overwhelmed by the tsunami that knocked out backup power that kept reactor cooling systems running, according to documents supplied by the company. The monitor was set to go off at high levels of radiation, an official said.
Nuclear expert Arnie Gundersen just confirmed that some of the Japanese nuclear reactors were severely damaged even before the tsunami hit.
Specifically, Gundersen reports that the containment vessel at Fukushima 1 started leaking and melting down before the tsunami hit. Similarly, Gundersen notes that the fuel pool at reactor 4 cracked and started leaking after the earthquake and before the water hit.
Remember that Japanese seismologists had warned for years  that Japan’s reactors were extremely vulnerable to earthquakes, with one top seismologist noting:
It’s like a kamikaze terrorist wrapped in bombs just waiting to explode.
Gundersen also points out that Florida’s nuclear reactors are vulnerable to tidal surges from hurricanes, and California’s reactors vulnerable to tidal surges caused by earthquakes.
And he notes that the attempt to release pressure at Fukushima failed 3 out of 3 times: 100% failure rate.
Gundersen notes that this shows that the entire design of these old-fashioned nuclear reactors is a failure.
Finally, Gundersen says – I’ve repeatedly noted  – that conditions are in many ways even more precarious in the U.S. than in Japan.