richard, the explosion was due to hydrogen build up within the building external to the vessel which reached an explosive concentration

@tay yes, you can think of it as boiling sea water in a pot until it's dry. the next time you fill it with water to boil, it will slow down the heat exchange.

there absolutely was radiological release at TMI (three mile island)

@Dean I thought that the generation of hydrogen gas was created when the rods were showing out of the water? then on the pressure release the mass pressure (of hydrogen gas) reacts with the oxygen rich environment inside the containment building? am i mistaken?

Edano-san has said that the containment vessel is sound...

Here's how you can help with the earthquake relief efforts. You can send items to these addresses through your local neighborhood Japanese Post Office:

They really need :
1.Foods (instant foods, dietary supplements, baby foods)
2.Warm blankets (That north part of Japan is still really cold now)
...3.Cothings
4.Baby clothings, and DIAPERS!!!!

Attn: Earthquake relief supplies
Miyagi Prefectural Office
3-8-1, Honcho
Aoba-ku, Sendai city, Miyagi
980-8570, JAPAN

Attn: Earthquake relief supplies
Iwate Prefectural Office
10-1 Uchimaru Morioka city, Iwate
020-8570,JAPAN

Attn:Earthquake relief supplies
Aomori Prefectural Office
1-1-1 Nagashima, Aomori city,
Aomori, 030-8570, JAPAN

Attn:earthquake relief supplies
Fukushima Prefectural Office
2-16 Sugitsuma-cho, Fukushima City
960-8670, JAPAN

Any water will cool the fuel. Clean water is preferred but if that cannot be pumped in the seawater has to be used to keep the fuel from melting more. However, it is the boron that tells me they have had melting already because boron is only needed if the control rods did not go all the way in or the fuel is not in a physical configuration that can be controlled by the control rods such as a puddle. This is backed up by the hydrogen, cesium and iodine present. The cores have already had some melting at this point.

American Search/Rescue Teams being sent to Japan: www.usaid.gov

From what I gather, the reactor will be generating significant heat for a couple of weeks, even when nominally shut down. Dean, correct me if I'm wrong.

chris, the production of hydrogen occurs when the cladding of the fuel pellets over heat and interact with the water in a zirconium-water ignition

@dean and mike Thanks for the input guys, any thoughts on the global effects of the radiation fall-out from these reactors?

It's worth confirming the radiation levels reported to the IAEA and NISA. The last radiation Sunday night (according to Kyodo) was of 1557.5 microsievert. That's a tiny dosage, scarcely enough to cause poisoning. The only caveat I can think of is that I hope Kyodo has got it right that the unit is actually "microsievert". If it's milli- or even just normal sievert, the situation is obviously different.

john, true.. the boron is injected to act as a poison and absorb neutrons to keep from re-criticality

ty lisa

if they detect cs-137 or Ir-131 outside the plant with monitors it means that some fuel has breached and leaked out the radioisotopes

fran. depending on the magnitude or what we call SOURCE TERM of the accident. it can eventually circle the globe but typically at lower levels

Have we heard any more about the ceasium137 that was detected earlier? Have these levels increased?

@Dean. Are they doing this work from inside the plant? Or the outside

BTW, I was a nuclear plant chemist for 5 years here in the states. I'm employed in another industry now.