What Happened in Japan?

Having just watched "Nuclear Nightmare: Japan In Crisis" with Paula Zahn, I must say that Paula Zahn and the Discovery Channel got it pretty much right.

The Richter 9 earthquake, and the 47 foot tsunami after it, resulted in unbelievable damage to the Fukushima nuclear plants (all six of them).

Fukushima was designed for a 7.9 earthquake and a 30 foot tsunami.

The worst result was at plant four. The spent nuclear fuel in plant 4 was safe - until the water in the pool either splashed out drained out through a crack. The fuel overheated, reacted with the steam, and created hydrogen. The hydrogen exploded on day four - at dawn on March 15. But guess what? The hydrogen was inside the partially melted nuclear fuel. The explosion sprays nuclear material into the air, causing a "radiation spike" and the majority of the radioactive material release.

Or maybe not. Plant two found a radioactive water release, which was not stopped until April 5. But this plant's containment was suspected to be damaged on March 15 - and the water release probably started as soon as the damage occurred.

Worse, and a surprise to many in the nuclear community - the plant 2 containment was probably damaged and cracked on day 1. Either the earthquake shock wave cracked the suppression pool, called a torus, or the tsunami bent the entire nuclear plant on it's foundation, which cracked the torus.

And the massive radioactive release began on day 1. Day 1, when the fuel had not had time to decay to anything anywhere near safe levels.

This is my conclusion, for whatever it is worth.

And it is the best way I know to explain how the release could be 1/10 of what Chernobyl released. (Al though I believe the release was way below that.)

We won't know for sure for six months or more, when humans can examine the plants carefully.