Jdietz

Seems more something an admin need to fix, support forum?

Getting no preview either, just a link which fails.

Can't download any of your attachments JF, and it looks like no one else can (except maybe moderators). Don't know why. Can you maybe inline them instead?

The police charged with the water cannon operation seem to have run for the hills...

Still getting 'you don't have permission' on all downloads, no idea why.

But the readings here http://www.bousai.ne.jp/eng/ seem all a bit lower again than yesterday, and most are around background level.

Good, if they're still steaming they still have water

I'm going to tune out for a bit, getting dizzy of repeats of the 'Helicopta~ Wa' fragment.

Direct radiation: not a chance (square of the distance intensity falloff)

Radioactive particles: not with this wind, can change if the wind turns, but concentrations still very low anyways.

NHK World:

Also, the water in the storage pools of reactors #5 and #6 isn't circulating and the pools are heating up about 5 degrees C per day.

Right now the temperature is around 60 degrees C, so within about 8 days it will reach 100C and start boiling off.

There is currently no fuel inside reactor #4, as it was moved to the storage pool for maintenance some time before the quake. So no need to add water or anything to that reactor, it's inert.

The storage pool though has next to the old fuel, a full set of reasonable 'fresh' fuel as well.

It may be just the wind direction, but I've noticed the two online Geiger Counters have been steadily dropping since yesterday, from 0.2 - 0.3μSv/h to 0.1 - 0.15μSv/h. Note however that at these low levels handheld meters are notoriously imprecise. The delta is real though.

Gomenasai (ごめんなさい) (I'm sorry) can almost be translated straight as Mai pen rai (ไม่เป็นไร)... not that much cultural difference in that regard.

Yeah you got it

NBK World: No significant change in radiation levels after water dump.

Spent fuel pond almost empty

Dumping water mostly missed the pool

Pool size about 2,000 tons. 1/3rd needs to be filled to submerge the fuel rods.

I'm no expert, but I can't see how it will be safe any time soon. If there was a partial melt down (#1 and #3) as reported earlier, then it would seem the meltdown continues, at least for awhile. For a meltdown to be stopped, it would seem that all the components would have to be lined up to mechanical tolerances, perhaps fractions of mm's - in order to move components (in to water reservoir, for example) as needed.

From all we've been hearing, much of the mechanical components at the reactors have been damaged.

I've posted this already but let me repeat:

A full meltdown in these kind of reactors means that the radioactive material in the rods melt, to form a puddle at the bottom of the steel containment vessel. This will further dissipate the heat of the reaction until it becomes a brittle substance you can basically break away from the bottom and remove piece by piece. Expensive cleanup, yes. Dangerous Nuclear Explosion, not really.

I'm really more worried about the storage pools. The reactors never bothered me too much.

As far as I know, the power line has been run up to the plant, but not connected to the switchboard yet due to radiation levels at the site. I'll see if I can find a reference.

Big lag in CNN's reporting. They're way behind. They are overly negative now. They need to access this thread guys.

Basically forget about being informed by any US based news station. They seem to exist solely to push their respective political stance.

Here is some interesting reading about 'pool fires'

http://brc.gov/e-mails/September10/G_Thompson_WasteConfRpt09.pdf

The accident sequences that could result in water loss from the SFP, including beyond design basis earthquakes, various types of seal failures and dropped shipping casks, and the Zircaloy cladding fire issues have been studied by the NRC staff. The results of these studies are provided in NUREG-1353, “Regulatory Analysis for the Resolution of Generic Issue 82, Beyond Design Basis Accidents in Spent-Fuel Pools”.

Although these studies conclude that most of the spent-fuel pool risk is derived from beyond design basis earthquakes, this risk is not greater than the risk from core damage accidents due to these beyond design basis earthquakes. Therefore, reducing the risk from spent-fuel pools due to events beyond the safe shutdown earthquake would still leave a comparable risk due to core damage accidents. The risk due to beyond design basis accidents in spent-fuel pools, while not negligible, is sufficiently low that the added cost involved with further risk reduction is not warranted.

If they pull this off, we're more or less out of the woods. The reactors themselves never really worried me much, as even a worst-case failure only means a very expensive site cleanup (contained melt-down).

The open storage pools are a big deal though IMHO, once they get power and circulation back to them, it will be safe.

Cleanup will be a long term operation though, I don't think anything at the Daiichi site will ever produce power again.

At this time it looks like the situation inside the reactor cores is pretty much under control. Don't forget the reaction has been stopped at the moment of the quake, and it has been cooling down ever since. With sufficient cooling this should have taken 4 to 5 days.

If they now get at least some water in the pools, this will lower the ambient radiation level enough so some work can be done around the sites.

Also they plan to finish AC power hookup today, and install new sea water pumps.

I would say, 6 days in, no *kaboom*, very low levels of radiation outside the plant, that they are doing a marvelous job all considering.

NHK showing image of police water cannot truck, saying they carry four tons of water...

Funny accurate typo though ( cannot truck )

Edit: Saved original quote so this keeps making some sense

As long as the helicopters get at least -some- water in, the radiation level at the site will drop enough to get the fire engine crews closer.

The storage pools are described as being 'twice the size of an Olympic pool, and stacked 10 high'

They normally hold 15 meters of water, so some serious refilling needed.

NHK world:

- 4 water dumps have been completed.

- 40 minutes max mission duration

- More helicopters on their way to relieve current ones

Edit: JF got it, no need for me to double up, I'll sit back and read.

NHK World: Officials have arrived and spraying water with the water cannon is imminent.

- Also a helicopter has arrived again

Well if they manage to refill the pool, the amount of direct radiation will lower significantly (they will spray water mixed with boron, inhibiting the reaction)

Right now water is boiling off at a nice clip, so I don't think it will be much worse, compared to them boiling dry and decomposing

The big issue with these pools is that they are not contained at all, except by the now non-functional outer structure.

The fuel rods are far further apart then they would be inside a reactor core, so it is very unlikely the will reach criticality, but without water they will start melting and can spread their contents over a large area.

As all these rods have been cooling down for quite a while, this will be even more slow-motion then inside the reactor cores. So as long as they occasionally get some water in the pools it won't be acute.

The water-cannon approach will be starting any moment now, let's see how that goes.