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Fukushima Daiichi; photo

by tuasfait Wed May 11th, 2011 at 11:47:05 PM EST

An electric engineer recently worked at the plant, and posted a short diary at a Japanese site. One photo caught my attention.

This message is posted at the plant's shelter room, where some 1,000 workers take rest. It is from children of a Fukushima kindergarten. The message says, "Thank you for your work. Take care!!" (paraphrasing)

Workers do not have enough space to rest; they sit on corridors and staircases, stand up, view this message, and set to work, I think.

This binder contains all messages from all over the world.

Whatever collective shortcomings we are suffering, the workers are doing their best, I am sure.


Japan disaster threads:

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NHK WORLD English
Tokyo Electric Power Company says water may be leaking from breaches in the No.1 reactor at the Fukushima Daiichi nuclear plant, causing a sharp drop in the water level inside the reactor.

Tokyo Electric sent workers inside the building to adjust the water gauge of the reactor.

The utility had suspected the gauge wasn't working properly because the water level hasn't been rising despite pumping in 150 tons of water daily to cool the reactor.

On Thursday morning, it was found that the water level was more than one meter below the bottom of the fuel rods, suggesting a large volume of water is leaking into the containment vessel.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 08:03:28 AM EST
Two weeks ago I didn't think the picture can get worse, but it did...

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Thu May 12th, 2011 at 09:05:24 AM EST
[ Parent ]
When I wrote

What if only the two water level gauges failed?

...I was thinking of the water levewl gauges erring in the other direction...

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Thu May 12th, 2011 at 09:09:34 AM EST
[ Parent ]
Same here, i was thinking that logically, cracks in the gauge system would give readings that were artificially low....

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 09:17:40 AM EST
[ Parent ]
Oh, and then the question is: in what direction do the water level gauges err in the other two stricken reactors?...

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Thu May 12th, 2011 at 10:29:18 AM EST
[ Parent ]
60's vintage DP cells, could literally read anything after an earthquake and/or an explosion.
by tjbuff (timhess@adelphia.net) on Thu May 12th, 2011 at 06:29:30 PM EST
[ Parent ]
Reactor 1 fuel rods melted, sank to bottom | The Japan Times Online
There are actually no tools specially designed to check the water level inside the containment vessel, but Tepco said that it made estimates based on other factors, including the pressure level inside the containment vessel.


*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Fri May 13th, 2011 at 02:48:58 AM EST
[ Parent ]
"it was found that the water level was more than one meter below the bottom of the fuel rods"

One meter below the bottom of the fuel rods?

Isn't that well into catastrophe territory? Might they perhaps instead mean one meter below the TOP of the fuel rods?

by LondonAnalytics (Andrew Smith) on Thu May 12th, 2011 at 11:01:01 AM EST
[ Parent ]
One possibility is that whatever meltdown was going to happen has already happened and that the water level is one metre below where the bottom of the rods would have been had there been any rods left and the rods are now in the form of molten (and refrozen on contact with water) corium at the bottom of the reactor.

Another possibility is that, two months after the reactor shut down, the fuel is no longer as "hot" as it would have been otherwise. Hot fission products will have decayed and unspent fuel might not heat up enough to melt or burn the Zircon fuel rods.

If the fuel rods are indeed fully exposed, presumably they have been for long enough that whatever disaster was going to happen has already happened.

Economics is politics by other means

by Migeru (migeru at eurotrib dot com) on Thu May 12th, 2011 at 11:06:35 AM EST
[ Parent ]
Thanks Migeru.

Even fully-spent fuel-rods need a lot of cooling, don't they, for quite some time after being withdrawn from the reactor?

by LondonAnalytics (Andrew Smith) on Thu May 12th, 2011 at 11:11:37 AM EST
[ Parent ]
Don't thank me as if I really knew what I'm talking about - I'm just a former physicist and am speculating from the best information I think I have so far.

The protocol for dealing with spent fuel appears to be to cool it in water for a year in the reactor's own spent-fuel pool, after which it is cool enough to move to on-site storate by human operators.

But this does not necessarily mean that a year is needed for the fuel to cool down enough for the rods not to melt or burn. It means a year is sufficient time (or comfortbly more than sufficient time, given the "defence in depth" philosophy at play here) for the fuel rods to not emit enough gamma radiation to be unsafe to handle by human operators wearing standard protective clothing. Keeping them in water for a whole year may also use the water as a radiation shield (for beta radiation mostly), not necessarily for cooling.

Economics is politics by other means

by Migeru (migeru at eurotrib dot com) on Thu May 12th, 2011 at 11:19:39 AM EST
[ Parent ]
Japan Earthquake: nuclear plants - Page 429
Lets just get the facts straight, using this data that 200GJ of energy is required for a melt through we can then calculate using the formulas provided that the time for melt through is using Po=1380MW
0 minutes after shut down - 4hours
01 hours after shut down - 5 hours
02 days after shut down - 11 hours
30 days after shut down - 26 hours
60 days after shut down - 36 hours

It's pointed out that that is time for fuel melt rather than melt of core through the bottom

Any idiot can face a crisis - it's day to day living that wears you out.

by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 11:18:32 AM EST
[ Parent ]
I would go with water level is one metre below where the bottom of the rods would have been had there been any rods left, then.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Thu May 12th, 2011 at 11:22:09 AM EST
[ Parent ]
Nuclear fuel at Fukushima No. 1 unit melted after full exposure | Kyodo News

Tokyo Electric Power Co., the operator of the crippled Fukushima Daiichi nuclear power plant, revealed Thursday that holes had been created by melted nuclear fuel at the bottom of the No. 1 reactor's pressure vessel.

The company said it has found multiple holes adding up to several centimeters in welded piping. Earlier in the day, it said the amount of water inside the troubled reactor was unexpectedly low -- not enough to cover the nuclear fuel -- hinting that a large part of the fuel melted after being fully exposed.



Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 02:55:41 PM EST
[ Parent ]
So it was, after all, the meltdown that pierced the pressure vessel?

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Thu May 12th, 2011 at 04:02:49 PM EST
[ Parent ]
The first of what you wrote.

Tokyo Electric says temperatures at the bottom of the reactor are between 100 and 120 degrees Celsius, suggesting that the fuel has fallen and is being cooled in the water below.

The utility says it does not believe the fuel has completely melted and spilled through the bottom of the reactor. It adds that instead, the fuel appears to be being cooled inside the reactor.

But maybe these are premature conclusions: the new makeshift water level gages might have been unfit for the purpose, too.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Thu May 12th, 2011 at 12:31:16 PM EST
[ Parent ]
well no doubt TEPCO will withdraw these readings and apologise for the terrible mistake they have made in reporting this sometime tomorrow

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 12:52:40 PM EST
[ Parent ]
Probably an hour or so after Kan declares that nuclear power has been a disaster for the country, and that Japan is firmly committed to a nuclear future.
by ThatBritGuy (thatbritguy (at) googlemail.com) on Thu May 12th, 2011 at 01:07:53 PM EST
[ Parent ]
I know from practice that an awful lot of factors can give you a false reading when you attempt measurements with non-standard equipment under non-standard circumstances. Only the uncertainty here can have grave consequences...

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Thu May 12th, 2011 at 01:53:48 PM EST
[ Parent ]
Had a visitor today who used to work for a large Steel company, pre-retirement he was a specialist in ultrasonic examination of produced steel. he was talking about stress cracks in rail tracks, cracks in reactor pressure vessels and the time they were given unloaded reactor fuel tube material to test to see if it was possible for them to find a hole 15 thousandths of an inch across that had been made in the material. They explained that it would not be possible at steel production speeds of 20 feet per minute.  The Nuke people said that wouldn't be a problem as their tube speeds were measured in inches per hour.

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 02:48:47 PM EST
[ Parent ]
Reactor 1 fuel rods melted, sank to bottom | The Japan Times Online
Matsumoto also said that, considering the situation with the No. 1 reactor, the water level data from reactors 2 and 3 may not be credible.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 05:48:24 PM EST
[ Parent ]
That's a reply to this :-)

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Fri May 13th, 2011 at 02:43:11 AM EST
[ Parent ]
NHK WORLD English
Highly radioactive water was found leaking into the sea from the damaged Fukushima Daiichi nuclear plant on Wednesday. It's now been revealed that contaminated water levels in the No. 3 reactor's turbine building were already alarmingly high by Sunday.

Tokyo Electric Power Company plugged the leak with concrete after it found highly radioactive water flowing into the sea through a pit.

Radioactive cesium 620,000 times higher than the government-set safety limit was detected from the leaked water.

The contaminated water was streaming from the outlet of a pipe for electric cables.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 10:30:43 AM EST
NHK WORLD English
Tokyo Electric Power Company says the No.1 reactor at the Fukushima Daiichi nuclear power plant is believed to be in a state of "meltdown".

The utility company said on Thursday that most of the fuel rods are likely to have melted and fallen to the bottom of the reactor. Earlier in the day, it found that the coolant water in the reactor is at a level which would completely expose nuclear fuel rods if they were in their normal position.

The company believes the melted fuel has cooled down, judging from the reactor's surface temperature.

But it suspects the meltdown created a hole or holes in the bottom of the reactor causing water to leak into the containment vessel.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 08:09:58 PM EST
NHK WORLD English
A radioactive substance exceeding the state limit has been detected in pasture grass and vegetables in Tochigi and Ibaraki prefectures, neighboring Fukushima Prefecture.

3,480 becquerels of radioactive cesium were detected in one kilogram of pasture grass collected on May 5th in Nikko City, Tochigi Prefecture. The figure exceeds the state limit of 300 becquerels.

Also, at two different locations in Nasushiobara City, 3,600 becquerels and 860 becquerels of radioactive cesium respectively were detected in one kilogram of pasture grass collected on May 3rd.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 08:21:44 PM EST
Nikko city is about 150 km  south west of the plant, about 100 km due north of the centre of Tokyo. Not close to the evacuation zones

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 08:27:22 PM EST
[ Parent ]
NHK WORLD English
Tokyo Electric Power Company says an operation to transfer highly radioactive water pooled in the turbine building of the Fukushima Daiichi nuclear power plant's No.3 reactor caused contamination of the sea nearby.

Highly radioactive water was found leaking into the sea from a pit near the reactor's water intake on Wednesday.

The utility company says 1,200 becquerels of radioactive cesium 134 were detected in one cubic centimeter of sea water near the water intake on Thursday. The figure is 20,000 times the state limit. 1,200 becquerels of radioactive cesium 137, which is 13,000 times the state limit, were also detected.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Thu May 12th, 2011 at 08:28:33 PM EST
Man dies after collapsing during Fukushima plant work | Kyodo News
A worker at the crippled Fukushima Daiichi nuclear power plant died Saturday after collapsing while carrying materials as part of crisis-fighting operations, with a heart attack suspected as no radioactive materials were found on him, the operator said.
by afew (afew(a in a circle)eurotrib_dot_com) on Sat May 14th, 2011 at 02:55:48 PM EST
NHK WORLD English
he operator of the Fukushima Daiichi nuclear power plant is trying to identify where highly radioactive water from the No.1 reactor's containment vessel is flowing to, as the reactor is believed to have suffered a meltdown.

Tokyo Electric Power Company, or TEPCO, says the meltdown at the No.1 unit created holes in the reactor and damaged the containment vessel.

A large amount of highly radioactive water is believed to be leaking out, but it is not known where it is flowing.

TEPCO says the water could be flowing into the basement of the reactor building, but that workers cannot enter the site due to fear of high levels of radiation.


Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Sat May 14th, 2011 at 08:05:06 PM EST
TEPCO are now saying that reactor water failed in number one within 16 hours of the earthquake, temperatures reached 2800 degrees, and fuel slumped to the bottom where it has burned through in small ammounts. They are also saying that they are unsure of the levels in 2 and 3, so judging by their usual media relations, we'll find that 2 and 3 are melted on Wednesday. They Aare also saying that gas from 3 caused the  explosdion in 4

Any idiot can face a crisis - it's day to day living that wears you out.
by ceebs (ceebs (at) eurotrib (dot) com) on Sun May 15th, 2011 at 09:14:42 PM EST
[ Parent ]
Cryptome has posted some photos of the remains of the buildings and the conditions the workers are facing.
by ThatBritGuy (thatbritguy (at) googlemail.com) on Sun May 15th, 2011 at 10:03:38 PM EST
[ Parent ]
I wonder. On one hand, water supply in No. 1 failed for 27 hours, in No. 2 and 3 only 7 hours. On the other hand, that the No. 1 meltdown didn't end up as a total melt-through and cooling works now gives me the idea that what happened first was a lower teperature event: the fuel rods must have splintered when the casing and the cladding failed.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Mon May 16th, 2011 at 04:38:33 AM EST
[ Parent ]
Two-thirds back Kan over Hamaoka closure  Kyodo

SHIZUOKA -- Prime Minister Naoto Kan's decision to request the closure of the Hamaoka nuclear power plant was supported by 66.2 percent of the public, according to the results of a poll released Sunday.

About 47.0 percent of the respondents also backed the idea of reducing the number of reactors in the country. The weekend telephone poll said those who think Kan should resign immediately has dropped to 17.5 percent, down 6.1 points from the previous poll in April.

....

While a significant number of respondents called for a reduction in nuclear power plants, 57.9 percent approved the government's decision to limit reactor closures to Hamaoka, apparently reflecting public concern about potential power shortages.



"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Mon May 16th, 2011 at 12:42:41 AM EST
Government compiles timetable for dealing with Fukushima accident, evacuees Asahi

The government is compiling a schedule of measures to deal with the accident at the crippled Fukushima No. 1 nuclear power plant to provide evacuees as well as the international community a better idea of what to expect.

Prime Minister Naoto Kan is scheduled to attend the Group of Eight summit later this month and is expected to explain what the government is planning to do to stabilize the situation at the Fukushima plant, as well as in rebuilding areas struck by the Great East Japan Earthquake.

....

Sources said the timetable will be formally approved and announced May 17, in line with what is expected to be a revision of a work schedule by Tokyo Electric Power Co., the Fukushima plant operator, for how it plans to stabilize the situation.

TEPCO first announced the work schedule April 17, and had planned to revise it after about a month. Recent measurements at the No. 1 reactor indicating that large amounts of water are leaking from the containment vessel is but one factor that is forcing TEPCO to vastly revise its work schedule.



"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Mon May 16th, 2011 at 12:51:17 AM EST
TEPCO rethinks flooding reactor No. 1 after leakage found  Asahi

Tokyo Electric Power Co. has been forced to devise a difficult new step to cool a reactor at the stricken Fukushima No. 1 nuclear plant after its attempt to flood the pressure vessel and containment vessel with water failed. TEPCO said on May 14 that 3,000 tons of water found in the basement of the No. 1 reactor building had likely leaked from the containment vessel.

The utility had fed more than 10,000 tons of water into the reactor for cooling, hoping to flood the core vessel and outer containment vessel so that damaged fuel rods will be kept submerged, in a process called "water entombment." However, some of the water apparently leaked through pipe joints in the containment vessel.

With the failure of the operation, the utility is now considering recirculating the leaked water to try to cool the fuel rods, most of which are believed to have dropped to the bottom of the pressure vessel in a meltdown. According to TEPCO, workers discovered about 3,000 tons of water in the basement of the southeastern side of the reactor building on May 13.



"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Mon May 16th, 2011 at 12:59:19 AM EST
TEPCO: No.4 blast due to hydrogen from No.3  NHK

The operator of the crippled Fukushima Daiichi nuclear plant says the March 15th explosion at the No.4 reactor building may have been caused by hydrogen from the No. 3 reactor. Tokyo Electric Power Company has been investigating the cause of the explosion and fires.

It was initially thought that the March 15th explosion was triggered by hydrogen produced by damaged spent fuel rods in a pool inside the No.4 reactor building. But photographs of the pool taken in April show no damage to the rods.

TEPCO focused on ducts from the No.4 and neighboring No.3 reactor buildings that join into a single duct before an exhaust pipe. The company says that when it vented gas from the No.3 reactor through the duct, hydrogen may have seeped into the No.4 reactor building. Hydrogen that accumulated in the upper part of the No.4 reactor building may have caused the explosion.

The ducts from 3 and 4 are joined and hydrogen leaked from 3 to 4? Who could have known? Guess they weren't monitoring the atmosphere above #4 spent fuel pool for hydrogen. It only had the biggest and hottest fuel load on the entire site.

"It is not necessary to have hope in order to persevere."

by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Mon May 16th, 2011 at 01:09:04 AM EST
It is worth following videos of Arnie Gundersen of Fairewinds Associates. It would be interesting to see his say about this TEPCO announcement.

Gundersen argued finely that prompt criticality in the fuel pool of Unit 3 made that early explosion.

by das monde on Mon May 16th, 2011 at 04:00:38 AM EST
[ Parent ]
Guess they weren't monitoring the atmosphere above #4 spent fuel pool for hydrogen.

In addition to: not having a vent for the contingency of hydrogen accumulating there, not having a vent from the containment vessel bypassing the building, and not building the reactors completely isolated and redundant. The design faults just keep adding up.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Mon May 16th, 2011 at 04:32:49 AM EST
[ Parent ]
And Japan is not the only place where reactors of this design were built.

"It is not necessary to have hope in order to persevere."
by ARGeezer (ARGeezer a in a circle eurotrib daught com) on Mon May 16th, 2011 at 09:17:55 AM EST
[ Parent ]


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