This is going to be a ‘rough’ posting. I’m just tossing here some things that don’t need to be buried in the comments of the Quake posting (and you don’t need to sit through 20 graphics loading either).
The diagram of the GE Mark I reactor in Japan:
First off, an explosion happened at the Japanese Fukushima nuclear plant.
UPDATE: We’re up to two explosions, and a third reactor may be having issues.
To me, it
looks looked like it was a pump building behind the “big cubes” that I think contains the nuclear core and containment dome. Both CNN and Fox have had video of the explosion and they clearly show that the “tall towers” are between the camera and the “Cubes” and something behind that blows up. (UPDATE: Clearly now with better video we can see that the top of the outside building, the ‘weather shell’, of the reactor building itself, has blown off in what was most likely a hydrogen explosion. Not a very big deal really, but dramatic.)
Some video (all that’s available at the moment):
From RT, at about 1:40 you can see the layout of the site fairly well:
Here, you can see the explosion at about 47 seconds:
In comments on the Japan Quake thread:
Now I am a graduate of the Naval Nuclear Power Program and from everything I have heard on the news this is a meltdown in progress. Yes I know they still couch it as “possible” but that is the same thing they did for TMI and that was a meltdown in progress and was able to be stopped partially thru.
Now on to the video, the roof didn’t collapse from what I saw: it blew off. You can see the pressure wave lifting it off IMHO, then you get the dust cloud from the walls collapsing inward.
Now on that whole “the US is bringing in emergency coolant” reports from earlier was total PR. The problem was you need to circulate the coolant through the core and since the emergency generators were all DEAD that means the pumps don’t run. When the pumps don’t run, you can’t cool the reactor (unless it has an emergency passive system, but even that is short term see TMI). The problem wasn’t the lack of coolant, it was that the coolant was heating up past the flash point to steam and when that happens the pressure increases, thus starting to expose the core, thus generating more heat and the cycle continues. So that increased pressure could cause the explosion.
I believe those plants are BWR’s (boiling water reactors). It’s not necessary to circulate water (which is the coolant) just necessary to get some in the core. For them to not be able to do that implies severe damage inside the plant. I have been an operator at both PWR’s and BWR’s. Typically you have steam, diesel and electric driven feed pumps (at least in the US, Japan may not have the same requirements). As long as you have water and a way to get it in then keeping the core cool is easy…just vent the steam. BWR’s have a large ring called the torus filled partially with water and the steam from the reactor will get vented and quenched there.
It appears the steam line may be sheared so the steam driven auxFW pump isn’t working and maybe the quake threw the diesel off its mounts. The electric of course still needs electricity. Worst case scenario was we could always tie fire engines in and fill the drywell (containment which houses the core)
NNPS class 8304…
In this picture, the part to the right with all the pumps and turbines is what I think blew up.
a) This is going to be a major mess.
b) Nukes are going to have a very hard time for a couple of years.
c) Companies in the nuclear business are going to ‘have issues’ for a while.
d) It’s a good idea to have an emergency kit that includes iodine tablets and gas masks. Mine does.