Saturday, August 27, 2011

Japan's Ministry of Environment to Allow #Radioactive Ashes to Be Buried in Regular Waste Final Disposal Sites

Here we go. Radioactive Japan (or at least East Japan). Now all radioactive debris and garbage can and will be burned and buried.

The news headlines at various media outlets say "ashes that contain up to 100,000 becquerels/kg of radioactive cesium", but if you read the news carefully, as long as there are "countermeasures" to prevent the leakage of radioactive cesium into the surrounding environment, the Ministry is prepared to allow the ashes with any amount of radioactive materials to be buried in regular waste final disposal facilities.

From NHK News (8/28/2011):


Regarding the ashes after burning the disaster debris and regular household garbage contaminated with radioactive materials, the Ministry of the Environment has decided on a policy that will allow the burial of ashes that exceed 8,000 becquerels/kg of radioactive cesium, as long as there are countermeasures in place to prevent the leakage into the ground water.


The new policy was revealed during the meeting of experts affiliated with the Ministry of the Environment on August 27. So far, the Ministry's policy has been to allow the ashes with 8,000 becquerels/kg of radioactive cesium and below to be buried, but require the ashes that exceed that level to be stored temporarily while the Ministry decides on the disposal method.


Under the new policy, if radioactive cesium in the ashes exceeds 8,000 becquerels/kg but does not exceed 100,000 becquerels/kg, the ashes are allowed to be buried after they are bound with cement or put in a concrete container. If radioactive cesium exceeds 100,000 becquerels, then the ashes should be buried in the disposal facilities with a roof and/or with the concrete shield.


Radioactive cesium exceeding 8,000 becquerels/kg has been detected from the ashes from burning the regular household garbage in Kanto and Tohoku regions. The Ministry of the Environment has decided to apply the same rule as the disaster debris and allow the ashes to be buried. The municipalities will be able to bury the ashes that they have stored temporarily, but it may be difficult to obtain consent from the residents living near the disposal facilities.

The number "100,000 becquerels/kg" is significant in a sense, as the highest level of radioactive cesium found from ashes after burning the household garbage is 95,300 becquerels/kg in Fukushima Prefecture (link in Japanese). The number is high enough to clear the Fukushima garbage ashes, and it is probably high enough to clear garbage ashes from anywhere else.

Besides, as the NHK article states, even if it exceeds 100,000 becquerels/kg, all they need to do is to bury it in a disposal site with a roof or the concrete shield.

This new policy is to be applied to ashes from disaster debris and regular garbage that are radioactive. It's not mentioned in the article but the ashes and slag from the radioactive sewage sludge will be likely to be disposed under the same policy - i.e. burn and bury. (And remember the "mix and match" scheme.)

In the meantime, some garbage incinerators and sludge incinerators at waste processing plants and sewage treatment plants in cities in Kanto have become so radioactive that they have to be shut down. (More later.)

The entire country is to become the nuclear waste disposal site, because of one wrecked nuclear power plant. Talk about socializing the cost.

Another #Radioactive Rice from Chiba, 46 Becquerels/Kg

The rice has been cleared for shipping, because the level of radioactive cesium is much below the national provisional safety limit of 500 becquerels/kg which will pose no threat to health, according to the authorities in Chiba.

It's "Koshihikari" brand rice, but since it's not from Niigata the rice may be blended and sold. If it's blended, there is no requirement to state where the rice was harvested.

Caveat emptor, except the buyers don't have all information available to them to decide on their own.

From Sankei Shinbun (8/27/2011):


Chiba Prefecture announced on August 27 that 46 becquerels/kg of radioactive cesium was detected from the rice harvested in Ichikawa City. The prefectural government considers the level as "not affecting health", and has permitted the shipment of the rice as of August 27.


In Chiba Prefecture, a small amount of radioactive cesium was detected in the rice before the harvest in Shirai City. The detection of radioactive cesium in rice in Ishikawa City is the second in Chiba, the fourth in Japan. One location in Hokota City in Ibaraki Prefecture and one location in Nihonmatsu City in Fukushima Prefecture also had radioactive cesium in rice.


According to Chiba Prefecture, radioactive cesium was detected from the brown rice of Koshihikari taken on August 24 in one location in Ichikawa City. No radioactive cesium was detected in rice in Chiba City, Noda City, Narita City, Choshi City and Asahi City.


Rice can be sold and shipped in 42 municipalities in Chiba Prefecture now that the post-harvest testing has been complete and the level of radioactive cesium was below the provisional safety limit.

That's what the provisional "safety" limit is there for: to plant the idea in people's mind that anything below that limit is "safe". Clearly many producers and all of government bureaucrats from municipal level upward believe that, and excoriate consumers who still don't buy that argument (and don't buy the produce).

How Reactor 4 at Fukushima I Nuke Plant "Exploded", According to TEPCO

TEPCO is trying to explain what happened to Reactor 4 at Fukushima I Nuclear Power Plant. The explanation is that hydrogen gas along with radioactive materials from Reactor 3 flowed to the main exhaust stack, which then flowed backwards from the exhaust stack through Reactor 4's Emergency Gas Treatment System into the reactor building of Reactor 4.

To support this hypothesis, TEPCO released this diagram on August 27 press conference, which shows the surface radiation levels of the gas filters. Highest radiation is at the filter closest to the exhaust stack, lowest radiation at the filter closest to the reactor building.

The radiation seems low though, considering the amount of hydrogen it must have taken to render the building in a wreck, and therefore the amount of radioactive materials that came with the hydrogen gas must have been high. TEPCO's Matsumoto's explanation was because the gas from Reactor 3 came through the Suppression Chamber - i.e. wet vent. (Matsumoto's answer is via Ryuichi Kino's tweet; Kino is an independent journalist covering TEPCO from the day one of the crisis.)

Reactors 1 and 3 exploded with explosive sounds that were clearly heard and felt in the nearby towns. But there wasn't any such sound when Reactor 4 supposedly exploded. I say supposedly, because no one seem to know for sure exactly what happened, including TEPCO.

Cabinet Secretary Edano at that time said "explosion" of some sort at Reactor 4 on March 15, but the media report was focused on the mysterious "fire" that was spotted by a TEPCO employee who didn't bother to report to the local fire department (as he should have). The fire died down on its own, but then another fire flared up again the next day.

The initial report on the Reactor 4 incident was that one or two wall panels in the northwest corner of the reactor building were blown out, and there was some damage on the roof. It sounded minor.

Then all of a sudden we were shown the wreckage. One or two wall panels blown out? It was more like "one or two wall panels remaining".

Read my earliest post on Reactor 4, on March 15. No photo was released that day.

Here's what TEPCO has put down in the plant status report (page 16). TEPCO does say "explosion" but that's decidedly not what was reported back then:

  • At approx. 6:00am, March 15, an explosive sound was heard and the damage in the 5th floor roof of Unit 4 reactor building was confirmed. At 9:38am, the fire near the northwest part of 4th floor of Unit 4 reactor building was confirmed. At approx. 11:00am, TEPCO employees confirmed that the fire was extinguished.

  • At approx. 5:45am on March 16, a TEPCO employee discovered a fire at the northwest corner of the reactor building. TEPCO immediately reported this incident to the fire department and the local government andn proceeded with the extinction of fire. At approx. 6:15am, TEPCO employee confirmed at the site that there were no sign of fire.

It's about time we get the much better, and precise picture of what happened in the early days of the crisis, now that we've been better educated since March 11.

Reactor 3 Close-Up Photo from TEPCO

The crane was doing the dust sampling on August 24.

The crane was doing something else on August 22, when some Japanese watching the TEPCO Live Cam noticed the crane which looked like it was toppling over the reactor building. It did no such thing, it was simply folding.

Radionuclides Released into the Air from Fukushima I Nuke Plant, by NISA

as announced by Japan's Nuclear and Industrial Safety Agency (NISA) on June 6, 2011 (on page 13 of the PDF file). Click on the image below to view it in a separate window:

What's interesting about the numbers in the chart is:

1. Radioactive strontium came more from Reactor 2 and Reactor 3, 1 to 2-digit higher.

2. More plutonium came out from Reactor 2, 2-digit higher, not from Reactor 3 with MOX-fuel.

Strontium-89 (in becquerels)
Reactor 1: 8.2 x 10^13 (or 82 terabecquerels)
Reactor 2: 6.8 x 10^14 (or 680 terabecquerels)
Reactor 3: 1.2 x 10 ^15 (or 1,200 terabequerels)
Total: 2.0 x 10^15 (or 2,000 terabequerels)

Strontium-90 (in becquerels)
Reractor 1: 6.1 x 10^12 (or 6.1 terabecquerels)
Reactor 2: 4.8 x 10^13 (or 48 terabecquerels)
Reactor 3: 8.5 x 10^13 (or 85 terabecquerels)
Total: 1.4 x 10^14 (or 140 terabecquerels)

Plutonium-241 (in becquerels)
Reactor 1: 3.5 x 10^10 (or 35 billion becquerels)
Reactor 2: 1.2 x 10^12 (or 1.2 terabequerel)
Reactor 3: 1.6 x 10^10 (or 16 billion becquerels)
Total: 1.2 x 10^12 (or 1.2 terabequerel)

Neptunium-239, which decays to plutonium-239, was estimated at 7.6 x 10^13 becquerels, or 76 terabequerels, adding to 3.2 x 10^9 becquerels of plutonium-239 that came out. Again, most neptunium-239 came out of Reactor 2, whose reactor building is more or less intact and whose Suppression Chamber is said to have been damaged on March 15 morning.

In the PDF file linked above, NISA estimated 770,000 to 850,000 terabecquerels of radioactive materials have been released into the atmosphere from Fukushima I Nuke Plant (although they are now trying to lower that number), and additional 720,000 terabecquerels of radioactive materials are in the contaminated water at the plant.

(Thank you "Kyotoresident" for reminding me to put this up, which I did for my Japanese blog long time ago and forgot to do for this blog.)

Friday, August 26, 2011

#Fukushima I Nuke Plant SFPs with High Level of Radioactive Cesium

Well, so much for the Mainichi reporter who said "10 becquerels/liter" of radioactive cesium in the water spilled from the Spent Fuel Pool in Reactor 4 the other day. (It looks like he simply added 6.1 and 4.4, as you see in the chart below, and ignored the minor details like E+04...)

From TEPCO's handout for the press on August 25:

Have these numbers changed over time? If so by how much? I went to look for TEPCO's handouts in the past. In Reactor 1 SFP, the amount of radioactive cesium increased in 2 months, while in Reactor 3 SFP it has steadily decreased. In Reactor 4 SFP the amount is about the same (here's the May analysis). In Reactor 2 SFP the amount is also about the same.

Spent Fuel Pool 1:

Cesium-134: 12,000 becquerels/cubic centimeters
Cesium-137: 14,000 becquerels/cubic centimeters

Cesium-134: 23,000 becquerels/cubic centimeters
Cesium-137: 18,000 becquerels/cubic centimeters

Spent Fuel Pool 3:

Cesium-134: 140,000 becquerels/cubic centimeters
Cesium-137: 150,000 becquerels/cubic centimeters

Cesium-134: 94,000 becquerels/cubic centimeters
Cesium-137: 110,000 becquerels/cubic centimeters

Cesium-134: 87,000 becquerels/cubic centimeters
Cesium-137: 74,000 becquerels/cubic centimeter

OT: Radioactive Rice Hay Story Still Doesn't Quite Add Up for Me Personally

Quid est veritas?

The answer seems to be whatever is reported by the largest number of media outlets, mainstream and alternative. I'm just wondering aloud about my personal misgivings. (For those who insist on facts and figures only, you can stop right here, and have a nice weekend.)

The official story of radioactive rice hay is as follows:

The rice farmers left the rice hay in the fields after the harvest last fall, because the weather was supposedly not good. Too much rain, not enough time for the hay to dry.

When Fukushima I Nuclear Power Plant reactor buildings blew up, the rice hay was sitting on the ground. Then the rain and snow fell on the hay, contaminating it with radioactive materials.

The rice farmers collected the hay and sold/gave it to cattle farmers, who then fed the rice hay to their cows to improve the texture of the meat before the cows are sold to the market.

The cows were later found with radioactive cesium, and it was determined that it was from the contaminated rice hay that they ate.

Here are my problems:

If the rice hay had been sitting on the ground since August/September last year and it rained and snowed, wouldn't the rice hay pretty much rot by March this year?

The radioactive rice hay, particularly that from Miyagi Prefecture, has been shipped all over Japan. Why? Because, apparently, the rice hay from Miyagi (and Iwate) is considered high quality because the rice there is considered premium. Cattle farmers outside Miyagi purchase the Miyagi rice hay to feed their premium cows. This cattle farm in Yamagata proudly says their premium cows are fed with only quality rice hay from Miyagi and Yamagata.

Would the cattle farmers all over Japan buy the rice hay that was sitting on the ground for more than 6 months in rain and snow?

Another problem I have is that these cows start to be fed with rice hay one year before they are sold to the market. The cows that were found with radioactive cesium in July were sold and processed into meat between April and July. So they must have been eating rice hay since March - July of last year, and ate the radioactive rice hay for less than 3 months at most. Many cows were sold and processed in April, so they ate the radioactive rice hay for less than a month.

It turns out that Miyagi Prefecture is the number one producer of rice hay for cattle feed in Tohoku. Even if the rice hay producers do not roll the hay until it's ready to be shipped, I would think they keep it indoors at all times.

The government says it's the rice hay that contaminated the cows, the media outlets say so too. Producers, wholesalers and retailers of domestic beef all say so.

The cows got contaminated, and the rice hay got contaminated. But they may be the two separate events, and may not have happened the way people say it happened. Just my non-expert musings.

Democratic Party of Japan to Select New Leader, Ozawa Backs Kaieda

Prime Minister Kan finally steps down now that the renewable energy legislation has passed, the ruling party Democratic Party of Japan (DPJ) is going to hold an election to select the next party leader who will be the new prime minister of Japan.

The election is to be formally announced on August 27, and the voting will be on August 29, according to Jiji Tsushin (8/26/2011).

Jiji reports that there will be 5 candidates for the job. But it seems to boil down to two leading candidates backed by two warring factions within the DPJ.

On one side is Seiji Maeda, 49 years old former Minister of Foreign Affairs, backed by PM Kan and his faction. On the other, Banri Kaieda, 62 years old Minister of Economy, Trade and Industry, backed by the faction led by Ichiro Ozawa and ex-PM Yukio Hatoyama, both of whom like to be the "king maker".

Banri Kaieda has been an unabashed proponent of nuclear power as the Minister of Economy, Trade and Industry that oversees the nuclear industry in Japan.

5 candidates are:

  • Seiji Maehara, age 49, ex-Minister of Foreign Affairs

  • Yoshihiko Noda, age 54, Minister of Finance

  • Michihiko Kano, age 69, Minister of Agriculture, Forestry and Fisheries

  • Sumio Mabuchi, age 51, ex-Minister of Land, Infrastructure, Transport and Tourism

  • Banri Kaieda, age 62, Minister of Economy, Trade and Industry

Take your pick.

#Radioactive Rice in Chiba and Ibaraki, but Not in Fukushima

Not to the extent that may cause "chaos" as Professor Kosako predicted, but the prefectural authorities have tested the early harvest and radioactive cesium has been found in Ibaraki and Chiba.

The first to find radioactive rice was Ibaraki Prefecture, but the governor vows to fight the "baseless rumor" to promote rice from his prefecture.

From Sankei Shinbun (8/19/2011):


As the brown rice grown in Hokota City in Ibaraki Prefecture was found with radioactive cesium, Governor of Ibaraki Masaru Hashimoto answered the reporters on August 19 and said "There is no problem with safety. After the formal testing is complete by the end of August, we will persuade the consumers that there's nothing to worry about consuming Ibaraki rice", and that he will do his best to counter the "baseless rumor".


Governor Hashimoto emphasized safety by saying "It is not the level to worry, even if you eat [the rice] for one whole year". At the same time, he said "Since radioactive cesium has been detected in vegetables, I wouldn't have been surprised to see it detected in rice".


Radioactive cesium was detected in the brown rice in the preliminary testing. Total 52 becquerels/kg of radioactive cesium was found, with 23 becquerels/kg of cesium-134 and 29 becquerels/kg of cesium-137. The amount was far below the national provisional safety limit (500 becquerels/kg total radioactive cesium).

Governor Hashimoto is a former career bureaucrat and a graduate of Tokyo University.

Next to detect cesium in rice was Chiba.

From Mainichi Shinbun (8/26/2011):


Chiba Prefecture announced on August 25 that 47 becquerels/kg of radioactive cesium was found in the mochi-rice (glutinous rice) grown in Shirai City in Chiba Prefecture in the preliminary test before the harvest to survey the effect of radioactive materials from the Fukushima I Nuclear Power Plant accident. The amount of radioactive cesium was far below the national provisional safety limit (500 becquerels/kg). It is the second case of radioactive cesium detection in the country, the first one being in Hokota City in Ibaraki Prefecture.


According to the division for safe agriculture promotion in Chiba prefectural government, the brown rice taken at two locations within Shirai City on August 22 was tested. From one location, 47 becquerels/kg of radioactive cesium was detected, with cesium 134 22 becquerels/kg and cesium-137 25 becquerels/kg. The prefectural government plans to conduct the full survey on the brown rice after the harvest by the end of August, and if the rice tests under the provisional safety limit it will be allowed to be shipped.

But in Fukushima, hardly any radioactive cesium was detected in the early harvest rice.

From Yomiuri Shinbun (8/26/2011):


Fukushima Prefecture announced on August 26 the test results of the early-harvest rice harvested in a location in Nihonmatsu City, two locations in Motomiya City, and one location in Koriyama City.


From the location in Nihonmatsu City, 22 becquerels/kg of radioactive cesium was found. No radioactive cesium was detected in all the other locations. Based on the results, the prefectural government has allowed the rice harvested in these locations, except for one in Motomiya City, to be shipped. It will be the first shipment of rice from Fukushima after the Fukushima I Nuclear Power Plant accident.


According to Fukushima Prefecture, two types of early-harvest rice harvested on August 25 and 26 were tested. When the rice in the Nihonmatsu City location was milled, no radioactive materials were detected. As to the location in Motomiya City (Arai-mura), the testing was done on all rice fields. If the results show the level of radioactive cesium is less than the provisional safety limit, the rice will be allowed to be shipped.

These cities are located in "Naka-dori" (middle third) of Fukushima Prefecture where highly radioactive rice hay has been found. 500,000 becquerels/kg of cesium was found in rice hay in Koriyama City, and in Motomiya City, 57 kilometers west of Fukushima I Nuke Plant, the number was even higher at 690,000 becquerels/kg.

For your reference,

  • Fukushima's radioactive cesium detection limit, according to the prefecture: 10 becquerels/kg

  • Radioactive cesium (cesium-137) in rice in Fukushima before the accident: ND to 0.14 becquerels/kg, after milling

  • Radioactive cesium (cesium-137) in rice in Chiba before the accident: ND, after milling

  • Radioactive cesium (cesium-137) in rice in Ibaraki before the accident: ND to 0.045 becquerel/kg, after milling

    (source data for radioactive cesium in rice in Fukushima, Chiba, Ibaraki from Japan Chemical Analysis Center, from 2000 to 2009)

Contaminated Water Treatment System Stops for the Nth Time at Fukushima I Nuke Plant

Yomiuri Shinbun (3:59PM JST 8/26/2011):


TEPCO announced on August 26 that the contaminated water treatment system at Fukushima I Nuclear Power Plant stopped temporarily.


The pump that transfer the treated water from Kurion's cesium absorption system to AREVA's co-precipitation system stopped automatically at 2:21PM.


The treatment system last stopped on August 12 due to the abnormal signal from the control system. TEPCO thinks the stoppage this time is due to too much load on the pump, and is currently looking into the cause.

Thursday, August 25, 2011

#Radioactive Rice Hay From Miyagi Went Far and Wide

The government officials are slowly finding out the extent of radiation contamination all over Japan, and here are only two minor examples that I picked up today.

First, from Mainichi Shinbun Hokkaido local version (7/23/2011; sorry old news that I just found), I learned of the potentially radioactive beef from Hokkaido, which has largely escaped the radioactive plume blowing from Fukushima I Nuke Plant. The cows in Hamanaka-cho ate the rice hay from Wakuya-cho in Miyagi Prefecture that was contaminated with 1886 becquerels/kg of radioactive cesium, the level of which exceeded the national provisional safety limit for cattle feed (400 becquerels/kg). Hamanaka-cho is located on the eastern tip of Hokkaido, facing the Pacific Ocean.

Hokkaido officials are perplexed. "We never thought possible that anyone would buy rice hay from Honshu, because it's too costly." It was beyond their expectation.

The second one is the radioactive manure in Yamagata Prefecture. According to Sankei News (8/25/2011), the Yamagata prefectural government announced on August 25 that the cow manure at 7 cattle farms in the prefecture tested between 500 to 2600 becquerels/kg of radioactive cesium. All 7 farms were feeding their meat cows with rice hay from Miyagi Prefecture.

What I don't understand is why these farms even bought rice hay from Miyagi Prefecture, when their own prefectures are big producers of rice and there should be rice hay in abundance.

Well, since the leaf compost made out of radioactive dead leaves in Tochigi Prefecture can be mixed with dead leaves imported from Thailand and Bangladesh and sold all over Japan by one company, anything is possible.

#Radioactive Sludge by Children's Swimming Pool, Again, in Kawasaki City, Kanagawa

(UPDATE) According to Kanagawa Shinbun (8/26/2011), the radiation measurement of the sludge was: 1.70 microsievert/hour at 5 centimeters off the sludge, 0.42 microsievert/hour at 50 centimeters, and 0.21 microsievert/hour at 100 centimeters.)


16,500 becquerels/kg of radioactive cesium, and the park officials and the Kawasaki City government are at a loss what to do. They don't know where it came from, they don't know what to do with it.

On August 18, the sludge by the swimming pool in Hirama Park in Kawasaki City was also found with 12,400 becquerels/kg of radioactive cesium (see my post here). The air radiation level near the compost was 0.90 microsievert/hour.

From Tokyo Shinbun Kanagawa Local version (8/26/2011):


Following Hirama Park in Nakahara-ku, Inada Park in Tama-ku in Kawasaki City has also shut down the swimming pool because of the high air radiation level. Residents are surprised at the radiation contamination in their neighborhood, and the city officials are at a loss what to do.


The national safety limit for radioactive sludge is 8,000 becquerels/kg for disposal. But 16,500 becquerels/kg of radioactive cesium, more than twice the national limit, was detected in the sludge near the swimming pool entrance. The swimming pool is used by about 200 children per day during the summer break.


Some cloth and paper were found mixed in the sludge, and the Tama-ku center for roads and parks says it doesn't know where the sludge came from. Cleaning contractor who cleans the parks and the pool staff say they don't know either. It is unlikely that the sludge was from the swimming pool, according to the officials.


A citizens' group called "Peace and Smile Project Kawasaki" has been measuring the air radiation levels in Inada Park. One member says he was surprised. "My child comes to this park and use the swimming pool, so I measured several locations and found very high radiation far exceeding the normal level." He also says, "Kawasaki City is also measuring radiation, but the city is focused on locations with fallen leaves, and Inada Park was not included. I hope they measure more locations from now on."


One of the city officials who were measuring the air radiation at the site was totally at a loss. "We thought [the high radiation] was caused by fallen leaves. But it wasn't the fallen leaves. How much more should we investigate? We're confused because this is so beyond our expectation. If we expand the survey to many more locations, our regular daily work will be affected. To be honest, we would like the national government to do the survey".

The radioactive sludge at both parks were found by this volunteer group "Peace and Smile Project Kawasaki". Looking at their tweets on the Hirama Park sludge, the group has had such a struggle with the bureaucracy at the city offices and the Board of Education in Kawasaki City, who would rather not know about anything like highly radioactive sludge in the park. At one point, it seems the city was just going to have the sludge removed by a contractor and have it disposed as regular waste.

The word of the year in Japan for 2011 must be "想定外(soh-tei-gai)" - beyond expectation, unforeseen. From Kawasaki City officials to TEPCO officials to the national government ministers, it has been one big "beyond expectation" ever since March 11. (At least so they say.)

13% of Radioactive Iodine, 22% of Radioactive Cesium from Fukushima I Nuke Plant Landed in Central/Northern Japan

The rest was either blown off to the ocean or landed somewhere else in Japan.

Researchers at the National Institute of Environmental Studies (NIES) had their paper published in the electronic version of "Geophysical Research Letters" published by the American Geophysical Union on August 11, and they announced the result of their research in Japan on August 25.

The paper was submitted on June 27, and they kept quiet until the research was published. The researchers at this government institute therefore knew all along how bad the contamination was all over southern Tohoku and all of Kanto and part of Chubu.

Abstract of the paper titled "Atmospheric behavior, deposition, and budget of radioactive materials from the Fukushima Daiichi nuclear power plant in March 2011" by Yu Morino, Toshimasa Ohara,* and Masato Nishizawa, Regional Environment Research Center, National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan:

To understand the atmospheric behavior of radioactive materials emitted from theFukushima Daiichi nuclear power plant after the nuclear accident that accompanied the great Tohoku earthquake and tsunami on 11 March 2011, we simulated the transport and deposition of iodine-131 and cesium-137 using a chemical transport model. The model roughly reproduced the observed temporal and spatial variations of deposition rates over 15 Japanese prefectures (60–400 km from the plant), including Tokyo, although there were some discrepancies between the simulated and observed rates. These discrepancies were likely due to uncertainties in the simulation of emission, transport, and deposition processes in the model. A budget analysis indicated that approximately 13% of iodine-131 and 22% of cesium-137 were deposited over land in Japan, and the rest was deposited over the ocean or transported out of the model domain (700 × 700 km2). Radioactivity budgets are sensitive to temporal emission patterns. Accurate estimation of emissions to the air is important for estimation of the atmospheric behavior of radionuclides and their subsequent behavior in land water, soil, vegetation, and the ocean.

No other nuclides are discussed in the paper. But just for these two, if you look at the deposition and concentration simulation maps below, you see that at least half Fukushima Prefecture is "red", not just along the coast, which means the highest deposition of both iodine-131 and cesium-137 in high concentration. Southern Miyagi is just as bad as Fukushima , so is part of Ibaraki and Tochigi.

From their paper (page 19) - top row is the cumulative surface deposition amount of iodine-131 and cesium-137 from March 11 to 29; the bottom row is the average concentration of iodine-131 and cesium-137, again from March 11 to 29:

Now that their paper has been safely published, I wonder if these researchers will speak up (or the government will allow them to speak up) on the subject of radioactive contamination in much of Tohoku and Kanto. I doubt it, but I hope so. I wish they had spoken up much earlier, but I understand that having their paper published by a prestigious foreign academic society is very important for a scientific researcher.

(While I do understand the restriction on the researchers like not allowing them to publish the data before the paper is peer-reviewed and published, but I do wonder if the academic society or the magazine would have given them some sort of waiver. The paper was not about Chernobyl cesium deposition 25 years after people were evacuated from the area; it is about an on-going disaster where many people's lives may be at stake. Oh well.)

Wednesday, August 24, 2011

Radioactive Strontium in Firefly Squid Off Fukushima Coast, Says China

plus cesium-134 (half-life of about 2 years) and silver-110m (half life about 250 days). Strontium-90's half life is about 30 years.

From Jiji Tsushin (8/24/2011):


China's State Oceanic Administration announced on August 24 that strontium-90 was detected in the firefly squid caught off the coast of Fukushima Prefecture in the amount that was 29 times as high as the marine organisms along the coast of China. Cesium-134, which is normally never detected in the marine organisms along the coast of China, and silver-110m, a gamma-ray emitter, were also detected.


The State Oceanic Administration considers that "the western Pacific Ocean to the east and southeast of Fukushima Prefecture has been clearly affected by the nuclear plant accident" and has ordered the related agencies to strengthen the inspection of the marine products off the coast of Fukushima for radioactive materials.

On August 15, China's State Oceanic Administration announced that the evidence their survey ship had collected off the coast of Fukushima indicated a much wider contamination of the Pacific Ocean than the Japanese government had admitted so far. If the firefly squid was caught in this survey, they are talking about the Pacific Ocean 800 kilometers east of the Fukushima coast.

#Radiation in Japan: Government Believes Radiation Level Will Drop by 40% in 2 Years

even if they don't do any decontamination.

Well I guess they don't buy the argument of Russian scientists about the "ecological half life" of radioactive cesium in Chernobyl area being 62 to 420 years.

From Mainichi Shinbun (6:48PM JST 8/24/2011):


The Nuclear Disaster Countermeasures Headquarters of the Japanese government reported its plans on how to predict the future radiation levels in the area around Fukushima I Nuclear Power Plant to the Nuclear Safety Commission on August 24, and the Commission approved. According to the NSC, in the fields around the plant, the calculation shows the radiation will decrease by 40% in two years even without decontamination. The national government will determine its basic policy on decontamination of the area around the plant, and this calculation will be used as a guide.


The Countermeasures Headquarters focused on cesium-134 and cesium-134 among all the radioactive materials being detected around the plant, because they have longer-lasting effects. The calculation was based on radioactive cesium deposited in the fields from the past nuclear tests. Cesium-137, whose half life is about 30 years, would be half in 18 years considering the effect of dispersion by rain. Radioactive iodine whose half life is short and currently is not detected, and radioactive strontium which has little impact on the radiation level are not to be considered.

If they have decided to ignore strontium, it's safe to assume they have also decided to ignore plutonium or any other alpha and beta emitters. When they say radiation, it most likely means "air radiation".

Mainichi Shinbun also reports on the "Fukushima decontamination task force" set up by the national government. (Note that it's only for Fukushima Prefecture.) The key members of this task force are: the Ministry of the Environment, the cabinet office, and the Japan Atomic Energy Agency (JAEA) which is governed by the Ministry of Education and Science and the Ministry of Economy, Trade and Industry.

According to Mainichi, this powerful trio doesn't even know how to do decontamination yet. The trio is going to figure that out by experimenting in the area with relatively high radiation (e.g. Date City in Fukushima) to establish the official decontamination procedure and advise the municipalities.

Now I'm beginning to think that the regulatory agency for the nuclear industry being moved to the Ministry of the Environment was for a very good reason but not the government's stated reason of minimizing the collusion between the nuke industry and the regulators. The Ministry of the Environment has made it sound like it resents having to have the nuclear regulatory agency under the ministry. Au contraire, I think.

Here's the big chance for the minor ministry like the Ministry of the Environment to become a major player by leading the effort on decontamination, which is what the government has clearly decided to promote big time. The Ministry already has its vested interest group - the waste management industry which is going to play a very, very big role in the "cleanup" of 30 years or so worth of debris with varying degrees of radioactive contamination in Tohoku area. The Ministry has its own set of "experts" who will advise on decontamination and cleanup.

If anyone has accumulated a workable decontamination plan and method, that would be the Radioisotope Center of Tokyo University under Professor Kodama. But no, the national government has its own ideas, and the JAEA, of Monju notoriety, will be in charge.

Tuesday, August 23, 2011

#Radiation in Japan: List of Prefectures in Japan That Have Said They Will Accept Disaster Debris

35 Prefectures from Hokkaido to Kagoshima; in other words, all over Japan.

Good news for the residents of 4 cities in Ishikawa Prefecture who do not want radioactive debris burned in their neighborhood: the cities have suspended the decision to accept disaster debris because of the opposition from the residents, even though city officials are quite willing to accept debris to "help" Tohoku.

Why these officials want to "help" Tohoku by soiling their beautiful, historical cities with radioactive materials, however small, remains a mystery to me. The only answer that I can think of is what Haruki "Detarame" Madarame of the Nuclear Safety Commission said - "It's all about money, isn't it?"

For all the other cities and prefectures, residents beware. Beware of the mass media too, who is very quick to mislead by branding the residents as "selfish" and "uncaring" for refusing to burn the radioactive debris. Or firewood. Like a heap of abuse dished out to Kyoto City residents.

Glancing through the tweets of people in Japan knowledgeable about waste management, I'm beginning to realize that there is a figurative "waste management village" whose residents are made up of experts, industry people, government officials with vested, common interest in promoting waste processing facilities - just like the "nuclear power plant village" that may or may not be unraveling.

List of Prefectures and cities that will accept disaster debris:

Hokiaido 【北海道】
札幌市、函館市、根室市、標茶町、幌加内町、大空町、清里町、登別市、北十勝2町環境衛生処理組合、根室北部廃棄物処理広域連合、釧路広域連合、 愛別町外 3町塵芥処理組合、大雪清掃組合、北斗市、苫小牧市、石狩市、千歳市、十勝環境複合事務組合、平取町外2町衛生施設組合、日高中部衛生施設組合、室蘭市日鐵セメント株式会社

Akita 【秋田】

Yamagata 【山形】

Gunma 【群馬】

Saitama 【埼玉】

Tokyo 【東京】

Kanagawa 【神奈川】
横浜市、川崎市、 横須賀市、藤沢市、茅ヶ崎市、逗子市、大和市、南足柄市、箱根町、厚木市、相模原市、小田原市、泰野市伊勢原市環境衛生組合、高座清掃施設組合、足柄東部清掃組合、足柄西部清掃組合

Toyama 【富山】

Ishikawa 【石川】
金沢市、輪島市、加賀市、能登市、七尾鹿島広域圏事務組合、羽咋郡市広域圏事務組合、白山石川広域事務組合、 奥能登クリーン

Yamanashi 【山梨】

Gifu 【岐阜】

Shizuoka 【静岡】

Aichi 【愛知】

Mie 【三重】

Shiga 【滋賀】

Kyoto 【京都】

Osaka 【大阪】
岸和田市貝塚市清掃施設組合、吹田市、高槻市、枚方市、茨木市、岬町、柏羽藤環境事業組合、泉南清掃事務組合、泉佐野市田尻町清掃施設組合、東大 阪都市清 掃施設組合、箕面市、摂津市、寝屋川市、豊中市、熊取町、堺市、四條畷市交野市清掃施設組合、泉北環境整備施設組合、池田市、門真市、大阪市

Hyogo 【兵庫】
神戸市、姫路市、尼崎市、明石市、西宮市、洲本市、芦屋市、相生市、豊岡市、加古川市、宝塚市、三木市、高砂市、三田市、加西市、篠山市、養父 市、丹波 市、南あわじ市、朝来市、淡路市、播磨町、佐用町、香美町、新温泉町、揖龍保健衛生施設事務組合、中播北部行政事務組合、洲本市・南あわじ市衛生事務組 合、小野加東環境施設事務組合、くれさか環境事務組合、猪名川上流広域ごみ処理施設組合

Nara 【奈良】

Wakayama 【和歌山】

Tottori 【鳥取】

Shimane 【島根】

Okayama 【岡山】

Hiroshima 【広島】

Yamaguchi 【山口】

Tokushima 【徳島】

Kagawa 【香川】

Ehime 【愛媛】

Kochi 【高知】

Fukuoka 【福岡】

Nagasaki 【長崎】

Kumamoto 【熊本】

Oita 【大分】

Miyazaki 【宮崎】

Kagoshima 【鹿児島】

New Word to Learn for Non-Japanese Speakers: "Dango"

"Dan-goh", with the second syllable pronounced long. If you pronounce it short, it will mean "sweet rice-flour dumplings", which look like these in the photo.

So what is "dango"? It is a long-standing business practice in Japan across many, many industries but particularly heavily used in the construction industry whereby the competitors get together and arrange who will win the bid and at what price. It's a fine example of "give and take", or "I scratch your back and you'll scratch my back later". A contractor who is not to get the job this time is scheduled to get the next one, or a contractor who is to get the job promises to subcontract or form a joint venture with a competitor. No one will underbid. Industrial harmony. The winner is pre-selected, and to make up the appearance (and to make the selection committee look like it is doing the job) the bidders often craft their bids that are intentionally inferior to the bid by the pre-selected winner.

In exchange for the orderly market, it usually ends up costing the taxpayers a bit more and enriching those local government officials with strong ties to these colluding companies.

Now, Miyagi Prefecture, whose governor's idea of "recovery" is to build a memorial museum and memorial park for the March 11 disaster, has started to solicit bidding on the disaster debris cleanup jobs. With huge amount of money to be spent freely (remember, now it's the national government paying for the cleanup) to the tune of 240 billion yen (US$3.13 billion) - the largest project size for Miyagi Prefecture - the nation's construction industry got in shape quickly to do the "dango" to divvy up the money and help clean up the disaster debris, which is likely to be pretty radioactive.

Radiation? What radiation? We have the "dango" to do.

From Asahi Shinbun (5:01AM JST 8/24/2011):


Miyagi Prefecture announced on August 23 that the cleanup of disaster debris in the Ishinomaki district will be awarded to the joint venture of 9 companies headed by Kajima, one of the largest general contractors in Japan. The project cost will be about 240 billion yen [US$3.13 billion], the largest ever for the prefecture. The selection committee made of experts chose between the two joint ventures who submitted the proposals.


The prefecture was reportedly informed of a "dango" taking place, where the Kajima JV's winning the contract had been predetermined by the participants even before the proposals were submitted to the selection committee.


Miyagi Prefecture has 15 million tonnes of disaster debris, which is equal to 23 years worth of regular garbage in the prefecture.

More and much more to come. The debris cleanup, which was going nowhere at all after 5 months since the March 11 triple disaster, will be done very quickly now that the big contractors are assured of the big money. Already, also in Miyagi Prefecture, a big paper company has signed a contract with the prefectural government to burn the disaster debris for the company's thermal power generation to power the company's plant in Ishinomaki City. The excess electricity will sold to Tohoku Electric, according to Kahoku Shinpo (in Japanese; 8/23/2011).

They're going to burn the radioactive debris to generate electricity, and they will get paid for taking the debris as fuel.

And these general contractors in joint ventures will burn, bury, and burn more, with the help of junior JV partners which often include small construction firms owned and operated by the senior officials in the local municipalities, including mayors.

The other JV who supposedly lost out on this bid will surely get their job for the next round of disaster debris cleanup, because that's the whole point of "dango" - secure job for everyone, over time.

Professor Kodama of Tokyo University warned against this very "dango" in his testimony in the Diet. Ah but Japan is finally on the way to recovery. "Dango" collusion is back! Radioactive or not.

...And Condenser Pipe for Reactor 4 Spent Fuel Pool Leaks

Part of normal daily life as we've seen at Fukushima I Nuclear Power Plant.

The stainless pipe that circulates water for the condenser unit for the Spent Fuel Pool of Reactor 4 has been found leaking. The amount of radioactive materials in the water (coming out of the SFP) is very low, says TEPCO, only 10 becquerels/liter. It is a very minor drip, of one drop in 30 seconds or so, according to Mainichi Shinbun (in Japanese; 8/23/2011).

TEPCO's countermeasure is to put a bucket under the dripping pipe. The cooling operation continues uninterrupted.

TEPCO's handout for the press on August 23 is still only in Japanese. I put the green circle around the leak location:

(UPDATED) TEPCO: 3 Sieverts/Hr Radiation in SARRY Was from Sludge, Maybe, Hopefully

(UPDATE) TEPCO's Matsumoto seems to think the high radiation was caused by "a few grams of radioactive cesium", according to Mainichi Shinbun (8/23/2011).


TEPCO has a simple diagram to explain the super-hot 3 sieverts/hour radiation on the drain pipe of Toshiba's SARRY, not the main pipe that feeds contaminated water to the vessels.

It was all too clear from the press conference that TEPCO didn't even know for sure. They were guessing that's what was, which was the fluctuating water pressure during the flushing caused the float to bob up and down (see the TEPCO diagram below), which in turn caused the water with highly radioactive sludge to be sucked out into the drain pipe.

Why did TEPCO think that was the cause? Because after they blasted the drain pipe with water the radiation level got lower, so it's got to be the sludge in the pipe.

Therefore, their countermeasure is going to be to close off the valve at the vessel so that the contaminated sludge from the vessel doesn't flow out to the drain pipe. Looks like a basic design flaw to me, but who am I to say?

Here's TEPCO's explanation (handout on 8/23/2011), if you can believe it:

(UPDATED) 2 Nuclear Reactors Shut Down In Virginia Following M5.9 Earthquake

(UPDATE) According to the plant operator Dominion's press release, the external power has been restored. The release doesn't say what time it was restored. One of the diesel generator was taken offline after the generator coolant leaked, but the 5th generator at the plant took its place. There has been no leak of radioactive materials in the environment other than that during the normal operation.


From NBC Washington (2:35PM EST 8/23/2011):

A nuclear power plant located in Louisa County, the epicenter of the earthquake in Virginia, has shut down.

The North Anna Power Station, operated by Dominion Power, has two reactors. The plant declared an "unusual event" in the wake of the 5.9 magnitude quake, which is the lowest stage on the plant's emergency scale.

As a result, the plant has been shut down.

Check back with NBC Washington for more updates as they become available.


The AP reports the plant is being run off of four emergency diesel generators, which are supplying power for critical safety equipment.

(And what does the stock market do on the news? Bots go overdrive of course and ramp up the market. What else do they do? Sell gold and silver! Make sense, doesn't it? Time to buy risky assets (stocks) in times of uncertainty.)

(Oh I see. Maybe when they evacuated the exchanges they instructed the bots to just keep buying stocks no matter what...)

Monday, August 22, 2011

3 SIEVERTS/HR at SARRY in #Fukushima I Nuke Plant

SARRY, a cesium absorption system in the contaminated water treatment complex at Fukushima I Nuclear Power Plant was stopped when the extremely high radiation of 3 sieverts/hour was detected during the operation to exchange the cesium towers.

From Asahi Shinbun (9:37PM JST 8/22/2011):


TEPCO announced on August 22 that a high radiation of about 3 sieverts/hour was detected at Toshiba's SARRY which was recently introduced as part of the contaminated water treatment system at Fukushima I Nuclear Power Plant. Due to the high radiation, TEPCO could not exchange parts [cesium towers], and the water processing [using SARRY?] had to be stopped.


SARRY started the full operation on August 18. According to TEPCO, workers were exchanging the parts that absorb cesium for the first time in the morning of August 22, when they found a spot with high radiation on a pipe in the system. Unless the radiation level gets lower, the workers cannot exchange the parts. TEPCO is trying to flush out the radioactive materials in the pipe with water.

So, as with Kurion's system, Toshiba's SARRY also needs human intervention to exchange highly contaminated cesium absorption towers. Toshiba's towers supposedly have built-in lead sleeves inside the towers, but it is the pipe that's radiating 3 sieverts/hour radiation.

Oops. When it comes down to, it is the basic items like pipes, pipe fittings, hoses and pumps that give.

"Ecological Half Life" of Cesium-137 May Be 180 to 320 Years?

A Wired Magazine article dated December 15, 2009 cites a poster session presentation of the research of the Chernobyl exclusion zone at the American Geophysical Union conference in 2009, and says radioactive cesium may be remaining in the soil far longer than what the half life (30 years) suggests.

To note: it was a poster session presentation, and I'm looking to see if it has been formally published in a scientific paper since then.

From Wired Magazine (12/15/2009):

SAN FRANCISCO — Chernobyl, the worst nuclear accident in history, created an inadvertent laboratory to study the impacts of radiation — and more than twenty years later, the site still holds surprises.

Reinhabiting the large exclusion zone around the accident site may have to wait longer than expected. Radioactive cesium isn’t disappearing from the environment as quickly as predicted, according to new research presented here Monday at the meeting of the American Geophysical Union. Cesium 137’s half-life — the time it takes for half of a given amount of material to decay — is 30 years. In addition to that, cesium-137’s total ecological half-life — the time for half the cesium to disappear from the local environment through processes such as migration, weathering, and removal by organisms is also typically 30 years or less, but the amount of cesium in soil near Chernobyl isn’t decreasing nearly that fast. And scientists don’t know why.

It stands to reason that at some point the Ukrainian government would like to be able to use that land again, but the scientists have calculated that what they call cesium’s “ecological half-life” — the time for half the cesium to disappear from the local environment — is between 180 and 320 years.

“Normally you’d say that every 30 years, it’s half as bad as it was. But it’s not,” said Tim Jannik, nuclear scientist at Savannah River National Laboratory and a collaborator on the work. “It’s going to be longer before they repopulate the area.”

In 1986, after the Chernobyl accident, a series of test sites was established along paths that scientists expected the fallout to take. Soil samples were taken at different depths to gauge how the radioactive isotopes of strontium, cesium and plutonium migrated in the ground. They’ve been taking these measurements for more than 20 years, providing a unique experiment in the long-term environmental repercussions of a near worst-case nuclear accident.

In some ways, Chernobyl is easier to understand than DOE sites like Hanford, which have been contaminated by long-term processes. With Chernobyl, said Boris Faybishenko, a nuclear remediation expert at Lawrence Berkeley National Laboratory, we have a definite date at which the contamination began and a series of measurements carried out from that time to today.

“I have been involved in Chernobyl studies for many years and this particular study could be of great importance to many [Department of Energy] researchers,” said Faybishenko.

The results of this study came as a surprise. Scientists expected the ecological half-lives of radioactive isotopes to be shorter than their physical half-life as natural dispersion helped reduce the amount of material in any given soil sample. For strontium, that idea has held up. But for cesium the the opposite appears to be true.

The physical properties of cesium haven’t changed, so scientists think there must be an environmental explanation. It could be that new cesium is blowing over the soil sites from closer to the Chernobyl site. Or perhaps cesium is migrating up through the soil from deeper in the ground. Jannik hopes more research will uncover the truth.

“There are a lot of unknowns that are probably causing this phenomenon,” he said.

Beyond the societal impacts of the study, the work also emphasizes the uncertainties associated with radioactive contamination. Thankfully, Chernobyl-scale accidents have been rare, but that also means there is a paucity of places to study how radioactive contamination really behaves in the wild.

“The data from Chernobyl can be used for validating models,” said Faybishenko. “This is the most value that we can gain from it.”

Update 12/28: The second paragraph of this story was updated after discussion with Tim Jannik to more accurately reflect the idea of ecological half-life.

Image: flickr/StuckinCustoms

Citation: “Long-Term Dynamics of Radionuclides Vertical Migration in Soils of the Chernobyl Nuclear Power Plant Exclusion Zone” by Yu.A. Ivanov, V.A. Kashparov, S.E. Levchuk, Yu.V. Khomutinin, M.D. Bondarkov, A.M. Maximenko, E.B. Farfan, G.T. Jannik, and J.C. Marra. AGU 2009 poster session.

NPO in Fukui Selling Buddhist Rosaries and Bracelets Made of Rikuzen Takata Pine

whose bark was found with 1,130 becquerels/kg of radioactive cesium.

From Yomiuri Shinbun (12:59AM JST 8/23/2011):


A Sakai City, Fukui Prefecture-based NPO "Fukui Disaster Volunteer Net" has been selling the Buddhist rosaries and bracelets made out of the core of the trunk of the pine trees that was felled in the March 11 disaster in Rikuzen Takat City in Iwate Prefecture. The firewood made out of those pine trees was to be used at "Gozan no Okuribi" in Kyoto, but radioactive materials were detected [from the bark of the wood]. There was no radioactive cesium detected from the core.


Misao Higashikado of "Fukui Disaster Volunteer Net" says his organization wants to support the recovery by [commemorating the disaster] using the safe part of the wood.


One bead of the rosary/bracelet is engraved with "3.11", so that the memory of the disaster does not fade away. The NPO started to sell the rosaries/bracelets on the internet in late July. After the "Okuribi" on August 16, the NPO asked Ibaraki University to test for radiation, but there was no radioactive cesium detected from the trunk of the tree.


A Buddhist rosary sells for 3,000 yen (US$39), and a bracelet sells for 1,800 yen (US$23).


You can buy them at the website of the NPO "Fukui Disaster Volunteer Net", at

Disaster capitalism alive and well.

Oh wait, it is not really a capitalism. It's done by an NPO, non-profit organization. I should say "social entrepreneurism", then I'm totally politically correct.

(An NPO in Fukui Prefecture asking the university in Ibaraki Prefecture for testing? That's rather far, far away.)

Sunday, August 21, 2011

#Radioactive Sludge in Kindergartens in Tokamachi City, Niigata

Tokamachi City in Niigata Prefecture is located 205 kilometers west of Fukushima I Nuclear Power Plant. It's not even under the plume according to Professor Hayakawa's map.

Tokamachi is the green arrow. Fukushima I Nuke Plant is the red tag "D". (Map created at Jukurabe.)

From Yomiuri Shinbun (1:37PM JST 8/22/2011):


Tokamachi City in Niigata Prefecture announced on August 22 the result of the survey of radioactive materials in the soil in nursery schools and kindergartens in the city. 18,900 becquerels/kg of radioactive cesium was found in the sludge at the bottom of the container that collects rainwater at a public nursery school, and 27,000 becquerels/kg of radioactive cesium was found in the yard compost pile at a private kindergarten.


If the level of radioactive cesium exceeds 8,000 becquerels/kg up to 100,000 becquerels/kg, it has to be temporarily stored at a controlled processing plant. The city will consult the prefectural government as to how to dispose the sludge and the yard compost.


The samples were taken on August 12, and tested at a testing laboratory in Niigata. At both locations, the air radiation levels at 1 meter above the ground was 0.10 microsievert/hour and 0.14 microsieverts/hour, both of which were within the normal range.

More on Fukushima II (Daini): Loss of Function to Remove Residual Heat for Up to 2 Days and 23 Hours, March 11 to 14

I hardly paid any attention to Fukushima II (Daini) Nuclear Power Plant in the early days of the crisis, but I got curious reading the comment from the reader "Joe Neubarth" to the post on the eyewitness account of Fukushima II on the day of the earthquake:

"Core Damage comes from a loss of cooling. I know of no report of loss of cooling at that facility. Did they go dark when the one electrical transmission tower fell north of Fukushima during the earthquake? Did they then have a delay if the startup of Emergency Diesel Generators? If there was a delay or if they lost the EDG's totally THEN there might be a melt down, BUT I have not heard of this happening."

I didn't know either (or I totally forgot). Did they or didn't they? So I went to TEPCO's site and see what they say.

Fukushima II Nuke Plant has 4 reactors. When the earthquake hit on March 11, control rods were successfully inserted in all 4 reactors at 2:48PM. Then the tsunami hit, and at 6:33PM on March 11:

Occurrence of a Specific Incident Stipulated in Article 10 of the Act on Special Measures Concerning Nuclear Emergency Preparedness (loss of function to remove residual heat)

This happened on Reactors 1, 2, and 4, at the same time.

Then, the Residual Heat Removal System re-started one by one, on March 14:

Reactor 1: 1:24AM, March 14
Reactor 2: 7:13AM, March 14
Reactor 4: 3:42PM, March 14

So, the reactors weren't cooled for as long as 69 hours in case of Reactor 4, and 55 hours in case of Reactor 1. Is 55 hours long enough for the coolant (water) inside the Reactor Pressure Vessel to evaporate and for at least part of the fuel rods to be exposed and get damaged?

For all 4 reactors, the Reactor Coolant Filtering System came online between June 4 and July 17.

TEPCO also says the Suppression Chambers of Reactors 1, 2 and 4 suffered some event that caused the "loss of function to suppress pressure" in the morning of March 12. The function was restored on March 14 morning.

The above information is from TEPCO's status report on Fukushima II (Daini) Nuclear Power Plant as of August 21 (click to enlarge, or go to the link):

#Fukushima II (Not I) Nuke Plant Eyewitness Account on March 11

White smoke seen rising from Fukushima II Nuclear Power Plant in Tomioka-machi after the quake but BEFORE the tsunami.

It was related by people (husband and wife) who were in Kawauchi-mura, west of Tomioka-machi, quoting the unnamed acquaintance of theirs who works at the plant. They said they couldn't name the person as he is higher up in the organization.

The couple was speaking in an event organized by an independent journalist Yasumi Iwakami.