At dinner Saturday night, I told a bunch of friends that I strongly suspected the backup coolant pump generators worked perfectly until the tsunami hit, and that they would have easily survived the tsunami if only the air intake stacks had been tall enough to not take in water. Today, a WSJ article suggests I was correct. From the article: "When nuclear plants lose grid power, emergency on-site generation is supposed to furnish backup power. But some diesel generators at the Fukushima Daiichi plant failed a short time later due to the damage from the tsunami that followed the earthquake." Here's the LINK to the WSJ article. (I've experienced hydraulic lock in race engines with constant flow injection a handful of times. If you try to crank the engine when a cylinder is locked up like that, you'll often bend a rod. The solution is to put the car in gear and pull it backwards several feet, which releases the pressure in the cylinder. Well - try to imagine the damage if an engine, running at speed, takes in enough liquid to experience hydraulic lock - you'd break rods, cranks and probably heads and blocks, destroying the whole engine in less than a second!) Seems pretty clear that a 50 foot tall intake stack for each generator would have prevented the whole mess!