TEPCO finds sign of fresh nuclear fission at Fukushima reactor
TOKYO (Kyodo) — Tokyo Electric Power Co. said Wednesday that it has detected signs of a recent nuclear fission in the No. 2 reactor at the crippled Fukushima Daiichi power plant, but ruled out the possibility that a major criticality accident had occurred.
The plant operator injected early Wednesday water containing boric acid to control a possible nuclear reaction at the reactor, where nuclear fuel is believed to have melted when the cooling system failed following the devastating March 11 earthquake and tsunami. The company said the reactor’s temperature and pressure were stable.
As for the possibility of criticality, in which nuclear fuel sustains a fission chain reaction, the utility’s spokesman said such a phenomenon may have happened “temporarily or partially,” but he does not think enough energy has been generated to raise the reactor’s temperature and pressure.
The latest incident suggests that the plant’s seemingly stable situation could be fragile, even almost eight months after the crisis erupted. The world’s worst nuclear crisis in 25 years resulted in the meltdown of nuclear fuel in the Nos. 1 to 3 reactors at the Fukushima complex.
It may also affect the government and TEPCO’s plans to achieve a state of cold shutdown by the end of the year, although TEPCO spokesman Junichi Matsumoto said his company does not expect a major impact on the progress so far.
Possible evidence of a recent nuclear fission was found when gas was extracted from the No. 2 reactor’s primary containment vessel to check the radiation level on Tuesday.
TEPCO said it has found two types of radioactive xenon that are typically generated by nuclear fission and have relatively short so-called half-lives.
The two are xenon-133 and xenon-135, and as their radioactivity is reduced to about half in about five days and nine hours, respectively, their existence suggests that a nuclear fission took place recently, according to Matsumoto.
But TEPCO added that it needs confirmation and has asked the Japan Atomic Energy Agency for further analysis.
Even if the substances are confirmed, TEPCO believes that their density levels are quite low.
Water injection to keep the No. 2 reactor cool is continuing, and the government’s Nuclear and Industrial Safety Agency said the overall situation is “stable.”
(Mainichi Japan) November 2, 2011
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Interesting comment by Mochizuki over at Fukushima-Diary.com:
Breaking news “fission restarted at reactor 2″
Xenon133 and 135 are measured at reactor 2. Xenon is daughter of Uranium 235,half life time is 5.2 days(Xenon133),and 9 hours (Xenon135).
It proves the nuclear fuel is fissioning at reactor 2 still.
Tepco has starting injecting boric-acid solution into the (broken) reactor.
At reactor 2,Tepco finally started analyzing air filter of the container vessel on10/28/2011. As the result, they detected xenon 133 and 135. It may have been fissioning since months ago.
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By ENENEWS STAFF
Press Conference: Nuclear fission may also be happening in Reactors No. 1 and 3 — Curium mentioned… MORE
Nov. 1 — “Xenon was detected in the order of 10^-5 (ten to the power of minus 5) per cubic centimeter, says TEPCO’s Matsumoto in the press conference that is on-going right now in Japan,” reports EX-SKF, “It is significant enough to conclude it is not from March.”
“Matsumoto does think a localized, small-scale, and/or temporary nuclear fission may have occurred in Reactor 2,” the article continues.
Some possibilities put forth by TEPCO to explain the detection of xenon-133 and -135 include:
- “Neutrons that exist inside the reactor hitting uranium or plutonium”
- “Curium-244, -242, causing ‘spontaneous fission’”
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TEPCO: Radiation levels unchanged
TEPCO says the radiation reading taken on Wednesday near the No.2 reactor at the Fukushima Daiichi nuclear plant was basically unchanged from the day before.
The utility says the reading, taken at a monitoring post about 500 meters northwest of the reactor, stood at 293 microsieverts per hour at 9 AM, up only one microsievert from 24 hours earlier.
It says the radiation level near the compound’s west gate, about one kilometer from the No.2 reactor, was also unchanged at 11.2 microsieverts per hour, and that no neutron radiation was detected.
Readings at 8 other monitoring posts on Wednesday were also the same as Tuesday.
Wednesday, November 02, 2011 11:41 +0900 (JST)
Nuclear accident response plan revised
Japan’s Nuclear Safety Commission has decided to expand the areas that should take extensive nuclear accident safety measures.
The decision on Tuesday is a response to the accident at the Fukushima Daiichi nuclear power plant in March.
The new plan expands the areas to implement protective measures for nuclear accidents to a 30-kilometer radius around nuclear plants. Currently, they are limited to a 8 to 10-kilometer radius.
It also designates areas within about 5 kilometers of nuclear plants as precautionary zones, where residents must evacuate immediately in the event of a nuclear accident.
The plan reflects guidelines set by the International Atomic Energy Agency.
The NSC’s working group also noted the government should undertake anti-radiation exposure measures for residents within a 50- kilometer radius. These measures would include the distribution of iodine tablets to prevent radiation poisoning of the thyroid gland.
The number of municipalities needing protective measures will increase threefold.
Tuesday, November 01, 2011 19:04 +0900 (JST)
Um, may I ask a question? Why does this article not mention internal exposure?
Cesium in pollen not viewed as health risk
The Forestry Agency believes cedar pollen next spring contaminated by cesium fallout from the Fukushima No. 1 nuclear plant will be well below the legal safety limit.
The exposure from inhaling cesium-contaminated cedar pollen circulating from Fukushima Prefecture will have a maximum radiation reading of 0.000132 microsievert per hour, the agency said, based on a recent calculation of fallout affecting cedar needles and leaves.
In June, the education and science ministry studied cedar leaves in the town of Kawamata, located about 45 km from the Fukushima No. 1 nuclear plant, and determined the cesium-134 and -137 levels ranged from 54,300 to 177,600 becquerels per kilogram.
The Forestry Agency used those results to estimate the radiation exposure from pollen grains. If the level of contamination was 177,600 becquerels per kilogram and the concentration of pollen grains — a gauge of pollen density that shows how many grains are floating in 1 cu. meter of air — was 2,207, the exposure would be equal to 0.000132 microsievert per hour.
On average, the concentration of pollen grains is 89 in the Kanto region, but the calculation used 2,207, the highest figure recorded in the region in the past eight years.
The legal radiation exposure limit is 1 millisievert per year. If someone is exposed to 0.12 microsievert per hour for 24 hours over 365 days, it would equal about 1.05 millisieverts per year.
However, the entire mechanism of radiation transfer through cedar pollen remains a mystery.
Yoshihisa Matsumoto, an associate professor at the Tokyo Institute of Technology and a radiation expert, said he is unaware of any research regarding the transfer of radioactive materials on cedar leaves to pollen.
But he said it would be hard to imagine that the contamination level would be higher when the cesium is transferred to pollen.
Because the male cedar flower, which has pollen grains, becomes mature around this season, the agency will conduct tests on how cesium transfers to pollen from this month to January.
Fukushima has about 185,000 hectares of cedar forests.
Hiroki Matsumoto, an official at the agency, said cedar pollen is so light it can fly hundreds of kilometers, meaning it can reach densely populated Tokyo and surrounding areas.
He said cedar pollen that reaches Tokyo usually is carried by wind from the east, which means generally from Gunma, Saitama, Yamanashi and Shizuoka prefectures. But weather conditions could bring pollen from Fukushima, he added.
Matsumoto of the Tokyo Institute of Technology said even if the pollen is contaminated, people can use regular pollen-preventive tools to protect themselves.
Right. And I can fly.
8 years old girl has 2,915 Bq of Cesium
Fukushima local government made an innocent girl a radioactive material.
Minamisoma local government has finally published the result of WBC for 2,884 elementary and junior high school students.
They announced ONLY 274 of them had cesium-137, but the results about cesium-134 is concealed.
According to their trustworthy report, only 9 students had more than 20 Bq/kg, but data about cesium-134 is concealed.
The worst case was the 8 years old girl. She had:
- Cesium-134: 1,192 Bq
- Cesium-137: 1,723 Bq
- Total: 2,915 Bq
No wonder they did not check other radioactive material, such as strontium or plutonium.
Genkai nuclear reactor restarts after 1 month hiatus
SAGA (Kyodo) — Kyushu Electric Power Co. resumed operation of a nuclear reactor at its Genkai power plant late Tuesday that came to a halt as a result of human error nearly a month ago, after securing approval from local municipal leaders, company officials said.
The Fukuoka-based utility reactivated the No. 4 reactor at the plant in the town of Genkai, Saga Prefecture, at around 11 p.m. Tuesday, despite opposition among some local residents, with an eye to resuming power generation Wednesday afternoon.
It is the first time since the start of the nuclear crisis at the Fukushima Daiichi power plant in March that a utility has reactivated a nuclear reactor that went offline due to a technical problem.
The Animal Tragedy In Fukushima
November 1st, 2011
When people were told to being evacuation as Fukushima Daiichi melted down they were told by officials to leave their pets at home, they would be allowed to return in a few days.
It has been over 200 days.
This has turned out to be one of the more heartbreaking lies of the disaster. Believing the government officials, many in Fukushima left their pets at home. Once people evacuated the evacuation zone was closed and never reopened. People didn’t leave pets behind out of neglect or carelessness, their mistake was believing what they were told. This was compounded by the fact that most shelters would not allow pets. Pet owners had the additional stress and guilt of beloved family members being left behind to an unknown fate.
The government’s response was to do nothing. Many groups including veterinarians, have urged the government to simply allow animal rescue groups into the evacuation zone, even this was rejected. In response the government has cracked down even harder on people going into the evacuation zone by blocking roads and arresting any animal rescue volunteers they find in the zone. For over half a year now people have been risking their own safety to go into the zone to rescue animals and drop food and water for those still there. Many have been rescued, some on the verge of death, some with severe injuries and now litters of puppies and kittens are being found in the zone.
Many animals have died of starvation, others of injuries or disease gone untreated now that the humans have all fled. The tragic death going on in the evacuation zone is horrible, the videos that document what is being found are hard to watch. Now with winter approaching rescuers are finding even more urgency to their work. Roads will become impassible, they will no longer be able to drop food and water until spring. All they have asked for is to be allowed into the zone unhindered to do the work the Japanese government won’t bother to. In response the government leaked stories to the media of “animals turning wild” in an attempt to persuade the public to write them off. The reality is these animals are still the same domesticated pets they were before the disaster only now they are scared, traumatized and slowly starving to death.
There is an amazing network of rescuers, shelters, veterinarians and brave individuals going into the zone, they just need the government to cooperate.
What can people do? There are a number of ways you can help.
The Hachiko Coalition has been working tirelessly to coordinate with those trying to rescue the animals left in the zone. They have an action list of Japanese officials you can email to urge them to do the humane thing and allow rescuers into the zone unhindered to conduct rescues before winter arrives.
The group has started a visual petition where people from all over the world have sent in photos of their pets with their urging to the Japanese government written out. Hachiko Coalition is gathering these and forwarding them every day to government officials.
“We have a system in place, one by one, as I post, I am emailing, faxing, then couriering to the ministries and local governments”
The visual petition is ongoing, you can see the photos as they post on Facebook here. You can join the visual petition by taking a photo of your pet(s) with a sign urging the government to let the rescuers do their jobs and save the animals left in the 20km zone and send it to email@example.com.
You can also sign the petition at http://www.savefukushimaanimals.com/
Donations for some of the daring animal rescuers can be done through Chip-in for Charles Harmison and Yoshiko Wada. The two have made multiple trips into the zone and saved hundreds of animals.