They now know that the water decon system is functioning - the rad level in sludge is ^^^

[kristopher]

Tepco plays down decontamination failure

By MONAMI YUI and TSUYOSHI INAJIMA
BLOOMBERG

Decontamination efforts at the Fukushima No. 1 plant were halted Saturday after a filter expected to remove the radioactive element cesium for several weeks exceeded capacity in just five hours. Oil and sludge in the water contained much more radiation than expected, said Junichi Matsumoto, a spokesman for the utility.

Work on a self-contained cooling system has been suspended while the company seeks a solution, Matsumoto said at a media briefing in Tokyo Sunday. The setback won't delay achievement of a stable cooling status by mid-July, he said.

"Decontamination is the key to solving the problems at the plant," said Tadashi Narabayashi, a nuclear engineering professor at Hokkaido University.

Decontamination of about 105 million liters of water in basements and trenches at Fukushima No. 1 was halted after the level of cesium in a filtering unit reached 4.7 millisieverts of radiation, Matsumoto said Saturday. The units generally need replacement at a level of 4 millisieverts, and the company had expected the unit to last about a month, he said.

"Tepco should have ...

http://search.japantimes.co.jp/cgi-bin/nn20110620n1.html

One month is about 730 hours, so the ratio of radioactivity found to the radioactivity expected could be expressed as 730:5?

[intaglio]

1. I have a couple of problems with this

The report here says

Decontamination of about 105 million liters of water in basements and trenches at Fukushima No. 1

now thats 107 tonnes of water, however most estimates put the total amount in basements, drains and ditches at 100,000 tonnes of water Japan Today. Now either there is far less water in and around Fukushima reactor 1 than there is in and around reactors 2 and 3 or the reporter has confused litres with tonnes.

Second

after the level of cesium in a filtering unit reached 4.7 millisieverts

a time factor needs to be inserted here. Is it millisieverts per day, per hour or per minute?

I actually have a big problem with sieverts as a measure anyway because it supposedly measures the amount of biologically effective radiation. It is derived from the gray (the total amount of radiation absorbed) by multiplying by a fudge weighting factor depending on the type of emission.

/Edit to add
I notice the sievert figure is only for the amount of Caesium, which makes me wonder what other elements there are in the filters and what their emissions are.

[kristopher]

2. I think the rate of input is a key element on water volume

They are having to inject 500 tons a day into the cooling streams. They need that 500 tons to come from treated water because they verge on running out of storage for new input. So perhaps the 107 tons is the amount they managed to treat in 5 hours?

As for the radiation levels, to me the key point is the degree of an obstacle it presents to their effort to avoid releasing contaminated water at the rate of 500 tons a day. With levels nearly 150X higher than expected, that seems to still be an unanswered question.

See:
http://www3.nhk.or.jp/daily/english/20_13.html

And here is what the Asahi writes. It is longer than the other articles.
That threshold was set to prevent the exposure of workers to high radiation levels, but TEPCO said a radiation level of 4.7 millisieverts per hour was measured near the intake to one series of cylinders at around 0:54 a.m. on June 18..

http://www.asahi.com/english/TKY201106180163.html

[GliderGuider]

3. There are 1000 liters of water in a tonne

So that 105 million liters is 105,000 tonnes.

[intaglio]

10. Sorry tired

[SpoonFed]

5. Agreed

It's just more of the horribly inaccurate coverage of the units and the science. I think we can only hope to assume that the "exceeded after 5 hours" part and "expected to work for weeks" is true. Maybe the whole mSv (without rate) is in there for us all to believe the activity is nothing to see here.

And yeah, why no discussion of other isotopes/filth?

[SpoonFed]

4. Wow...

were halted Saturday after a filter expected to remove the radioactive element cesium for several weeks exceeded capacity in just five hours

The local news here is running "they've installed a filter and it's working".

Oil and sludge in the water contained much more radiation than expected

I would not be surprised at this point if that truly means TEPCO's "calculations" of how much toxic, polluted water they released is off by several orders of magnitude. It ran for 5 hours; if they had expected it to run for 50 hours (two days) it would have been an error of underestimating by 10x, but since they expected it to run for weeks or say 500 hours (3 weeks) that would be an error of underestimating by 100x. That's two orders of magnitude in science speak.

The C-word on steroids? hmm.

[SpoonFed]

6. It's quotes like these that make me furious...

From the OP...

While it struggles to shut down the reactors Tepco is also preparing to compensate victims of the disaster, including 50,000 households displaced because of radiation leaks.

They're probably trying to "compensate" victims during the disaster, and by compensate I mean get them to sign some paper that says some pittance, amount of cash in the middle of the crisis is the lump sum they're gonna get from the mofos for all time. Something along the lines of, "Are you tired of sleeping on the gynasium floor? We'll give you 5K for your entire former life".

"50,000 households displaced" --- really, displaced, not wiped out, contaminated beyond return. I want people to start talking about Japan in the same terms as Chornobyl. This area around the plant is an exclusion zone, so contaminated that it's no longer fit for human life for the forseeable future. It's not an evacuation zone in an reasonable sense, it's not a temporary displacement of households.

"radiation leaks" --- really... leaks... not catastrophic explosions, massive air and water contamination with no solution in sight. It's like saying the gaping shotgun chest wound patient on the emergency room table is "leaking some blood".

[Yo_Mama]

7. It's not even oil and sludge

it's the radiation levels in the water. The latest:
http://www3.nhk.or.jp/daily/english/21_05.html

The utility said the radiation levels in the water were much higher than expected.

On Monday, TEPCO conducted tests on different absorbents and concluded that it needs to change them more frequently. It also found that the amount of contaminated water flowing through the system should be varied depending on radiation levels.

This is a really big issue. The original capacity of this filtration system was thought to be 1,200 tons a day, which would give them enough filtered water to take care of reactor injection.

At best, they are going to be able to process far less water than they had expected.

In other articles, they tried to clean the filter and found it was too radioactive to be reused. The filter was supposed to last a month.

TEPCO backed off the "oil and sludge" bit yesterday.

[Fledermaus]

8. The setback won't delay achievement of a stable cooling status by mid-July??????????

FUBAR!

[Yo_Mama]

9. Yeah, that statement is total crap.

That was when they thought it was due to sediments and other stuff they could easily prefilter out of the water intake, but no dice.