Meltdown Likely Under Way At Japan Nuclear Reactor

[jfchandler]

BTW, the NISA people are saying the 600 to 800 radiation numbers Edano used and quoted in the AP excerpt below were not correct... Apparently he meant to be saying microsievert...

The level of radiation at the plant surged to 1,000 millisieverts early Wednesday before coming down to 800-600 millisieverts. Still, that was far more than the average

Edited March 16, 2011 by jfchandler

[jfchandler]

Warning broadcast of the potential for another strong earthquake... interrupting NISA news conference...

[jfchandler]

Good point.. The time stamp of this news report was 7:30 am ish... prior to the worker evacuation order...

The Agency says it can adjust the water levels by using the No.6 reactor's generator, which wasn't damaged by the tsunami. Workers are currently pumping water into the No.5 and No.6 reactors.

Wednesday, March 16, 2011 07:34 +0900 (JST)

conflicting reports, for sure. How can workers pump water in to #5 and #6 if there are no workers on site?

[jfchandler]

From NHK

TEPCO releases photo of No.4 reactor

Tokyo Electric Power Company has released a photograph of the No.4 reactor building at the Fukushima Daiichi nuclear power plant where fires were reported on Tuesday and Wednesday.

It shows that a large portion of the building's outer wall has collapsed.

The company produced the photo at a news conference on Wednesday.

The photo, shot the day before from the northwestern side of the reactor, shows that a large portion of the building's outer wall has collapsed. There is an 8-meter hole on the 4th floor, and the interior is visible.

Another 8-meter square hole was also confirmed on the outer wall of the building. Both appeared after an explosion early on Tuesday.

An ensuing fire near the 4th floor reportedly later went out on its own.

Flames were also found spewing from the building early Wednesday, but the utility company said they were no longer visible half-an-hour later.

Wednesday, March 16, 2011 11:57 +0900 (JST)

Edited March 16, 2011 by jfchandler

[brahmburgers]

Beware, the Ides of March

[Shurup]

Workers evacuated - now what? With no one trying to keep it under control the situation can get out of hands very fast and get very bad. Someone has to make a sacriface and keep trying ignoring the high radiation levels. If not workers NOW, it will be same workers LATER + a whole Japan + other countries that would get high rad exposure if it blow up.

I really hope the evacuation is a temporary measure but they have to get in and keep trying and I do feel sorry for them.

[jfchandler]

Here's the detail of the brief post earlier today on the Japanese govt. raising the permitted level of radiation exposure for workers at the Fukushima plant... 250 milli-sievert is a quite high exposure level...

NHK:

Gov't ups permissible radiation level

The Japanese government has revised upward the permissible level of radiation exposure for workers at the troubled Fukushima Daiichi nuclear power plant.

The health and labor ministry says that it raised the limit by a factor of 2.5, to 250 millisieverts, in cases of emergency.

The measure was adopted to secure enough time for workers at the power plant to engage in operations such as cooling down of the reactors.

Radiation above 250 millisieverts is said to cause health problems such as a temporary reduction in the number of white blood cells.

The health and labor ministry says it reached the decision after consulting with experts on the possible effects on workers.

The ministry explains that the measure was necessary to prevent a nuclear disaster. It says the international radiation limit is set at 500 millisieverts. It adds that medical experts have no clear knowledge about whether radiation of 250 millisieverts or lower will cause health damage.

Wednesday, March 16, 2011 09:56 +0900 (JST)

[midas]

this lady claims the spent nuclear fuel rods could be even more dangerous than the exploded reactors

http://www.youtube.com/watch?v=RiXIODVlfXk

[jfchandler]

The impression I got from monitoring the NISA press conference was that the evacuation was temporary...at least until if and when the radiation levels on site fall back...

The data they gave, and we posted above, was readings at the plant's gate boundary... And those had fallen back somewhat..

But at least in the televised news conference, they didn't mention the radiation levels directly at the reactors themselves...which of course would be higher.

Workers evacuated - now what? With no one trying to keep it under control the situation can get out of hands very fast and get very bad. Someone has to make a sacriface and keep trying ignoring the high radiation levels. If not workers NOW, it will be same workers LATER + a whole Japan + other countries that would get high rad exposure if it blow up.

I really hope the evacuation is a temporary measure but they have to get in and keep trying and I do feel sorry for them.

[bkkjames]

The impression I got from monitoring the NISA press conference was that the evacuation was temporary...at least until if and when the radiation levels on site fall back...

The data they gave, and we posted above, was readings at the plant's gate boundary... And those had fallen back somewhat..

But at least in the televised news conference, they didn't mention the radiation levels directly at the reactors themselves...which of course would be higher.

Workers evacuated - now what? With no one trying to keep it under control the situation can get out of hands very fast and get very bad. Someone has to make a sacriface and keep trying ignoring the high radiation levels. If not workers NOW, it will be same workers LATER + a whole Japan + other countries that would get high rad exposure if it blow up.

I really hope the evacuation is a temporary measure but they have to get in and keep trying and I do feel sorry for them.

Well the impression I get is that even if temporary it's game over. Now is the time to cut the face-saving media statements and let the people know the truth.

[jfchandler]

It seems a slow, downward spiral at Daiichi... nothing yet suggesting otherwise..

Are you guys just about ready to say complete failure mode is unavoidable or imminent?

[jfchandler]

The video feeds of the NHK broadcast via CNN and NHK's web site seem to have died for the moment...

Another feed in English is available here:

http://live.nicovideo.jp/watch/lv43386411

[bkkjames]

photo from reactor 4

http://www.yomiuri.c...-OYT9I00485.htm

[jfchandler]

NHK showing and reporting another strong EQ as of 12:52 pm Japan time/ 10:52 Thai time...magnitude 5-6....east area of Chiba...

Saying shouldn't be a tsunami issue...

Edited March 16, 2011 by jfchandler

[jfchandler]

NHK:

Radioactivity forecast system down

A computer system that forecasts the spread of radioactivity has not been working due to malfunctioning monitoring posts around a troubled nuclear power plant in quake-hit Fukushima Prefecture.

The Nuclear and Industrial Safety Agency says it does not know when the system will be back in operation.

The system, called SPEEDI, predicts how radioactive substances will spread in case of radiation leakage from nuclear power plants, based on measurements taken at various locations, prevailing winds and other weather conditions.

SPEEDI data are intended to be used to draw up evacuation plans for residents around power plants in case of accidents.

The system is monitored at government offices, including the industry ministry and the Nuclear and Industrial Safety Agency in Tokyo.

Friday's earthquake caused power outages around the troubled Fukushima Daiichi nuclear power plant.

The agency says it cannot expect the SPEEDI system to function fully, since many monitoring posts are not operating due to power outages.

Wednesday, March 16, 2011 10:25 +0900 (JST)

[jfchandler]

Reuters reporting just now:

Workers ordered to leave the quake-damaged Fukushima Daiichi nuclear plant were allowed back in after radiation levels fell.

Also 2nd confirming Reuters report:

Japan nuclear agency: Evacuation order of plant workers lifted at 0230 GMT after radiation falls.

Edited March 16, 2011 by jfchandler

[jfchandler]

JFC note - interestingly, the NISA officials in their televised news conference didn't mention the 10 mSv figure at 10:40 am... They used a 10:30 am reading and then skipped to 10:45 am... See broader readings in prior post above.

Radiation briefly topped 10 millisievert at Fukushima plant

TOKYO, March 16, Kyodo News

The radiation level at the quake-hit Fukushima No.1 [Daiichi] nuclear power plant reached 10 millisievert per hour at one point Wednesday morning, possibly due to the damage at its No.2 reactor the day before, the government's nuclear safety agency said.

The maximum level was measured at the plant's front gate at 10:40 a.m. It fell to 6.4 millisievert at 10:45 a.m. and to 2.3 millisievert at 10:54 a.m. but rose again to about 3.4 millisievert as of 11:00 a.m., the Nuclear and Industrial Safety Agency said.

Edited March 16, 2011 by jfchandler

[bkkjames]

interesting fall-out (interactive) mapping http://www.zamg.ac.at/aktuell/index.php?seite=1&artikel=ZAMG_2011-03-15GMT08:26

scroll down - it's in German I believe but the graphic is self explanatory

[bkkjames]

More on the big worry of the spent fuel ponds: some pretty scary scenarios in the comments section below the main story.

The pools "contain very large concentrations of radioactivity, can catch fire, and are in much more vulnerable buildings," he warns. If the pools lose their inflow of circulating cooling water, the water in the pools will evaporate. If the level of water drops to five or six feet above the spent fuel, Alvarez calculates, the release of radioactivity "could be life-threatening near the reactor building." Since the total amount of long-lived radioactivity in the pool is at least five times that in the reactor core, a catastrophic release would mean "all bets are off," he says.

Of particular concern: cesium-137 in the pool, at levels Alvarez estimates at 20 million to 50 million curies. The 1986 Chernobyl accident released about 40 percent of the reactor core's 6 million curies. In a 1997 report for the Nuclear Regulatory Commission, scientists at Brookhaven National Laboratory estimated that a severe pool fire—made possible by the loss of cooling water—could leave about 188 square miles uninhabitable and cause up to 28,000 cancer deaths.

Read more: http://www.businessi...3#ixzz1GjY3dAfy

this one is a good but frightening read - http://www.dcbureau.org/201103141303/Natural-Resources-News-Service/fission-criticality-in-cooling-ponds-threaten-explosion-at-fukushima.html

Edited March 16, 2011 by bkkjames

[jfchandler]

And I thought I was the bearer of bad news here.... James beats me by a mile...

[jfchandler]

NRC recognizes appropriateness of Japan's 20-km evacuation order

WASHINGTON, March 16, Kyodo News

The U.S. Nuclear Regulatory Commission said Tuesday it recognizes the appropriateness of Japan's order for residents within a 20-kilometer radius of the Fukushima No. 1 nuclear plant to evacuate following the continuing accidents there induced by the catastrophic earthquake.

The NRC said the order is almost identical to an evacuation order which the U.S. government would issue to its citizens in the event that people were exposed to radiation of above 10 millisievert in a nuclear accident.

The amounts of radiation detected in the areas around the Fukushima plant are much lower than this threshold, the federal agency added.

U.S. Ambassador to Japan John Roos also said in his statement issued Wednesday that U.S. nuclear experts back the measures taken by Japanese technicians.

''After a careful analysis of data, radiation levels and damage assessments of all units at Fukushima, our experts are in agreement with the response and measures taken by Japanese technicians, including their recommended 20 km radius for evacuation and additional shelter-in-place recommendations out to 30 km,'' he said.

''Today, our hearts remain with our Japanese friends,'' he added.

Edited March 16, 2011 by jfchandler

[Lopburi99]

Plenty of bad news to go around JFC....

Seems like dam_n near everything possible which could go wrong did - from the quake to the tsunami to the power outage to the...to the..

It's almost 1am in Michigan...going to bed...thanks guys, and prayers for the Japanese people.

Jeez, I just read bkkjames last post. Now I'm really bummed out...

Edited March 16, 2011 by Lopburi99

[bkkjames]

And I thought I was the bearer of bad news here.... James beats me by a mile...

sorry but this stands out from that second link:

Both United States and Japanese governments have for decades allowed re-racking of the pools to reduce the originally-designed minimum safe distance between the assemblies so that more rods can be stored in each pool. Utilities complained they were running out of storage space on site at the reactors. The problem is if the spent fuel gets too close, they will produce a fission reaction and explode with a force much larger than any fission bomb given the total amount of fuel on the site. All the fuel in all the reactors and all the storage pools at this site (1760 tons of Uranium per slide #4) would be consumed in such a mega-explosion. In comparison, Fat Man and Little Boy weapons dropped on Hiroshima and Nagasaki contained less than a hundred pounds each of fissile material.

[bkkjames]

REUTERS Radiation level in Ibaraki, north of Tokyo, at 300 times normal-Kyodo; Japan govt advice: Ibaraki reading well below hazardous level 8 minutes ago via web Retweeted by 6 people

http://twitter.com/l...881910634033152

Kyodo News: Radiation measured in Ibaraki (North of Tokyo) reached 15.8 microsievert, (300x normal level)

Edited March 16, 2011 by bkkjames

[jfchandler]

NHK reporting the worker evacuation this morning from the reactors lasted about one hour...until the onsite radiation levels declined.

[Alphonso]

NHK:

Radioactivity forecast system down

A computer system that forecasts the spread of radioactivity has not been working due to malfunctioning monitoring posts around a troubled nuclear power plant in quake-hit Fukushima Prefecture.

The Nuclear and Industrial Safety Agency says it does not know when the system will be back in operation.

The system, called SPEEDI, predicts how radioactive substances will spread in case of radiation leakage from nuclear power plants, based on measurements taken at various locations, prevailing winds and other weather conditions.

SPEEDI data are intended to be used to draw up evacuation plans for residents around power plants in case of accidents.

The system is monitored at government offices, including the industry ministry and the Nuclear and Industrial Safety Agency in Tokyo.

Friday's earthquake caused power outages around the troubled Fukushima Daiichi nuclear power plant.

The agency says it cannot expect the SPEEDI system to function fully, since many monitoring posts are not operating due to power outages.

Wednesday, March 16, 2011 10:25 +0900 (JST)

Haven't seen levels for Fukushima but for Ibaraki

Disaster Prevention and Nuclear Safety Network for Nuclear Environment
Real time radiation data collected via SPEEDI
2011/03/16 12:10

Ibaraki

Space Dose Rate List(nGy/h)
Ishigami        810
Toyooka         516
Funaishikawa    231
Yokobori        366
Oshinobe        391
Muramatsu       361
Mawatari        421
Onuki           356
Hiroura         494
Tsukuriya       377
Araji           297
Hitachinaka     575
Ajigaura        388
Ishikawa        284
Horiguchi       1240
Kuji            813
Isobe           485
Kadobe          703
Sugaya          283
Oba             215
Ebisawa         268
Sawa            845
Yanagisawa      364
Motokomezaki    Under servey
Nukada          360
Kounosu         420
Godai           468
Onuma           526
Mayumi          391
Uridura         198
Nemoto          262
Kume            151
Isohama         289
Tasaki          Under servey
Momiyama        614
Yatabe          237
Yoshizawa       238
Kamitoda        197
Tokushuku       185 

And for overall showing maximums where available.

The site seems overwhelmed so I won't add a link here.

[jfchandler]

James, let's keep the figures in some context...

The average annual radiation exposure from natural sources alone is about 2 MILLI-sievert...which is 2000 MICROsievert...

So, you can take whatever the HOURLY exposure readings are from nearby towns, and consider them in that context.

1 MILLI-sievert = 1000 MICROsievert

The hourly figures are elevated off site at the present time. But at those MICROsievert levels, that only becomes a significant problem if they remain that way...

Or to put in another way for the math challenged like me, the annual normal radiation exposure from natural sources would be about 2000 MICRO-sievert.

REUTERS Radiation level in Ibaraki, north of Tokyo, at 300 times normal-Kyodo; Japan govt advice: Ibaraki reading well below hazardous level

Kyodo News: Radiation measured in Ibaraki (North of Tokyo) reached 15.8 microsievert, (300x normal level)

Edited March 16, 2011 by jfchandler

[Jdietz]

Speedi radiation levels are reported in nGy/h (nanoGray per hour), to confuse matters even more

1 Gray = 1 Sievert. 1000 nGy = 1 μSv

Highest level I saw on that post was Horiguchi, 1240 nGy/h. So in units we are now used to that is equivalent to 1.24μSv/h or 0.001mSv/h, just a little elevated over background radiation.

[jfchandler]

Thanks for that translation, Jd... I had seen the same measurement reference, and had no idea what it meant... Didn't have time to looking or ask...

Meanwhile, since it seems this is getting to be more of an issue, maybe someone here knows the answer:

For radiation workers, such as those at Fukushima, what's the best kind of protection suits they can wear?

Can they wear something that would totally shield them from radiation exposure and inhalation?

Or, is the best available suiting something that only reduces the ambient radiation levels... if so, to what extent?

[Jdietz]

The suits contain their environment, so prevent you from taking in radioactive isotopes avoiding long-term exposure.

They are somewhat effective stopping some forms of radiation, but unless they are very heavily leaded and unwieldy don't count on them doing much in that respect.