The reactor is a 40 year old GE BWR (Boiling Water Reactor).

Here is a chronological breakdown of the events at the reactor in Fukushima

The plant was immediately shut down (scrammed) when the earthquake first hit. The automatic power system worked.All external power to the station was lost when the sea water swept away the power lines.
Diesel generators started to provide backup electrical power to the plant’s backup cooling system. The backup worked.The diesel generators ceased functioning after approximately one hour due to tsunami induced damage, reportedly to their fuel supply.
An Isolation condenser was used to remove the decay heat from the shutdown reactor.
Apparently the plant then experienced a small loss of coolant from the reactor.
Reactor Core Isolation Cooling (RCIC) pumps, which operate on steam from the reactor, were used to replace reactor core water inventory, however, the battery-supplied control valves lost DC power after the prolonged use.
DC power from batteries was consumed after approximately 8 hours.
At that point, the plant experienced a complete blackout (no electric power at all).
Hours passed as primary water inventory was lost and core degradation occurred. Portable diesel generators were delivered to the plant site.
AC power was restored allowing for a different backup pumping system to replace inventory in-reactor pressure vessel (RPV).
Pressure in the containment drywell rose as wet well became hotter.
The Drywell containment was vented to outside reactor building which surrounds the containment.
Hydrogen produced from zirconium oxidation was vented from the containment into the reactor building.
Hydrogen in reactor building exploded causing it to collapse around the containment.
The containment around the reactor and RPV were reported to be intact.
The decision was made to inject seawater into the RPV to continue to the cooling process, another backup system that was designed into the plant from inception.

They are using fire pumps to get the seawater into the reactor. It would seem to me that the circulation pipe work was damaged in the earthquake/tsunami and I wonder how they circulate the sea water when it heats up.

Since they can't see into the core, they cannot confirm the state of the core. Anna: When they add seawater they add Boric acid.

They are now running out of options and the greater fear is that there will be a meltdown in the reactor which would cause a breach in the containment.

Sorry for the long dissertation but there is so much misinformation circulating on TV I thought I would try to clarify what has happened. One thing that is for sure this is a terrible tragedy and it is far fron over.

http://oilprice.com/Energy/Energy-General/Thorium-A-Cheap-Clean-and-Safe-Alternative-to-Uranium.html
Back when they started developing nuclear reactors 50 -60+ years ago they had 2 choices, uranium or thorium, they chose uranium because it can make WMD's to kill people, now we are all in this fucked up situation together because of this choice, had they gone with thorium, there would be no danger like what we are facing now. Thank the military industrial complex.
http://en.wikipedia.org/wiki/Military-industrial_complex
The good news? They stockpiled a lot of thorium, enough to run our energy needs for centuries.

Didn't see this posted yet.

http://www.abc.net.au/news/events/japan-quake-2011/beforeafter.htm

It's like the NYT post. Drag the slider over the images to see the devastation.

The second blast... looks worse than the 1st
http://www.youtube.com/user/RussiaToday

And they are reporting that there has been a third

It takes real heroes to go in there and try to clean that up

Need to be really courageous.


About the 2 first explosions, the World Health Organization said there was not much radiations that came out
from the damage nuclear reactors.
But the situation is critical... now a 3rd explosion... ... hope it is not getting worse.


But I'm more concerned about the tsunami devastation. I read a lot of people never had time to escape. Because the epicentre was very close to the Pacific coast and because of the unexpected power of the earthquake, the big wave appeared too fast. I figure there's a lot more than 10,000 deaths.

Live Japanese TV... English language...
http://www.ustream.tv/channel/nhk-world-tv

This is a NOAA map showing the tsunami's effect as it crosses the Pacific ocean, I find this stuff very interesting, must be the surfer in me.
http://www.youtube.com/watch?v=IwXj9_8wcR8

... I get it ...

Topic has been moved to General Discussion.
Marx-Man's comment above has been edited, thanks for noticing the odd thread placement.

Sorry

Thanks for this long dissertation seamusoisin.

The German experts talked about most of what you are writing here too. One thing though. That Boric Acid that needs to be mixed in with the water to get the cooling water for the inner system will not be mixed with the sea water that is pumped into the power plant by the fire pumps.

There was a question about that and the expert says that for the mix to work properly, it has to be evenly and homogiously mixed in with the water, or it can't work properly.

At the same time they explained then, that the seawater that is used now, is not going inside the heart of the power plant, it is used to keep the metal casing around the space where the rods are cooled down. So, it does not need the boric acid.

That is what I understood from the experts here in Europe on TV.

As for the contamination, they say there is different kinds of danger from that. The particles that are spread by the explosions, which can land on the skin, or on clothes can be washed off and they can be breathed in to cause cancer in future (because ones inside the body they can't be flushed out anymore) that is why the people have to be removed from such a large area.

Wind carries those particles.

But I understood that these particles are not the same as the stuff (radiation) that is measured going up and down every time. They say this radiation has a very short halftime and is gone very quickly.

It would be good to have that cleared up as well? It is this fall out after all, that the whole world is worried about most. I know that it is different from the Tsjernobyl catastrophy, because that is a totally different reactor.

Tomorrow the wind will shift in the direction of Tokyo - sofar the wind carried most of the debri into the Ocean.Pretty much in the direction where the biggest purple/red wave pattern is going on that colourful map.

Don't know what to say.
I was optimistic but now it looks like out of control.
My sister-in-law & family are at 100 km distance from the Fukushima power plant. Still yesterday night, they said everything is all right, kids going to school, everything is quiet. Maybe now the historic message from Japanese emperor will make them more worried.
How is it possible... when the world worry so much, maybe sometimes in an exaggerated way especially about their own security, Japanese can stay so calm. They are preoccupied, but there is no panic.

We had planned to go to Japan this spring. We decided in February to report it next year.
Finally it was preferable this way. But can't wait to go back.
We asked them to come here in Canada. For the moment they didn't take it seriously...

Some thoughtful artwork and perhaps some inspiring comfort of this devastating tragedy.
http://naldzgraphics.net/inspirations/inspiring-graphic-artworks-an-advocacy-for-japan/

As this situation gets worse, imagine trying to deal with it when its all destroyed like this, I was reading yesterday how 2 lead scientist had resigned from GE in protest back in the 70's when they figured out that the design of these plants were flawed, this was the exact scenario that had them concerned, they were shown the door.




What's being reported
http://www.ustream.tv/channel/nhk-world-tv