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Instead of dietary fiber and calories, a retailer in Tokyo is displaying levels of radioactive cesium found in its fruits and vegetables, to alleviate any concerns about radioactive materials on produce. Along with the price, the outlet, run by Cataloghouse Ltd. in Tokyo's Shinbashi district, displays the cesium level found in the fruit or vegetable. If the radiation detection device installed in the outlet detects radioactive iodine or cesium in any produce, the figure is displayed next to the produce. The device can detect radiation levels of at least 10 becquerels per kilogram.

Kunihiko Takeda, a professor of engineering at Chubu University, said displaying the level is good for both the consumer and the retailer. "Just saying 'it's safe' will only create a sense of distrust," Takeda said. "If there is a display, consumers can purchase items even from Fukushima (Prefecture) after they are convinced. That would also be for the benefit of producers." A 37-year-old housewife who purchased grapes that were detected to have 22 becquerels of cesium said, "I am more assured because they conduct testing and display the results."

The outlet has a special corner where it sells produce from Fukushima Prefecture. The area features 22 fruits and vegetables produced by J-Rap Inc., a group of farmers in Fukushima, and sells rice produced by the group from before the March 11 Great East Japan Earthquake. Because consumers began avoiding vegetables grown in Fukushima Prefecture after radiation fallout from the accident at the Fukushima No. 1 nuclear plant, store officials decided to help the group by selling produce while displaying the radiation levels. Customers are provided with a list of radiation level standards established by various nations. The list includes the figures for the Ukraine, which has established standards much stricter than those in Japan following the Chernobyl accident in 1986. For example, while the radiation levels for fruits and vegetables in Japan are 500 becquerels per kilogram, in the Ukraine the levels are 40 becquerels for vegetables and 70 becquerels for fruits.

“Fortunately, due to the maintenance outage and the survival of one diesel generator, it seems that unit 5 reactor cores as well as spent fuel ponds have not suffered major fuel damage,” says the study. Though, Reactor No. 5 is mentioned again several pages later: “Total a posteriori [experienced levels] 133Xe emissions are 16.7 EBq, one third more than the a priori value [predicted levels] of 12.6 EBq (which is equal to the estimated inventory) and 2.5 times the estimated Chernobyl source term of 6.5 EBq.

If there was only 12.6 EBq of xenon-133 inventory that could be emitted from reactors 1-3 and spent fuel pool No. 4 — yet 16.7 EBq was experienced — where did the extra xenon come from, according to the study? “There is the possibility of additional releases from unit 5.” Another possibility is that recriticality has occurred in one of the reactor units. The study says the a priori emissions could have been overestimated, but discounts the notion that the initial 12.6 EBq figure so poorly underestimated the amount of xenon in Reactors 1-3 and SFP 4, “It is unlikely that the 133Xe inventories of the reactor units 1–3 were one third higher than estimated.”

ABSTRACT: ACPD – Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition SOURCE: Discussion Paper See also: Report: Fukushima Reactors No. 5, 6 now in crisis — Cesium outside release points up 1,000% in recent days — Local says Hitachi engineers coming to help (VIDEO)

On location report from Minami Soma – Strontium continues to be detected – “Too early for evacuees to be returning home.” Nationally declared “emergency evacuation preparedness zones” have been simultaneously lifted, however excessive risks may remain. Lab results from a radioactive contamination survey commissioned by Minami Soma City Council yield shocking results. - Desipite the lifting of the “emergency evacuation preparedness zone” designation, the perception is that contamination questions linger. - 59,000 people lived within the 20-30km “emergency evacuation preparedness zone”, 28,000 have relocated. Citizens view the lifting of the designation as good news, but unease persists.

From a local council perspective, the sooner evacuees return to start rebuilding the better. - Citizens infuriated with fuzzy official statements regarding severity of contamination, particularly when they have to consider the safety of their own kids. - Local government testing reveals strontium contamination, further complicating the situation. 17 spots around Minami Soma were tested, and four locations showed 33 – 1,113 Bq/kg of strontium contamination, including 100 Bq/kg from an area previously covered by the recently lifted evacuation advisory zone. - Regarding the possibility of internal exposure, Strontium is much more serious than cesium. As explained by a researcher from the Japanese Atomic Energy Institute, biological half life of cesium is 100 days vs 50 years for Strontium, which mimics calcium in the body.

It’s reasonable to expect that where there is cesium, there is also strontium, however it takes much longer to run tests for strontium and there are very few labs equipped to run the tests. - On the same day that the evacuation advisory zone was lifted, MEXT (Ministry of Education, Culture, Sports, Science and Technology) finally released results of strontium testing carried out around the plant. - Of the samples, collected since June, Futuba (inside the 20km zone) was the highest, at 5,700 Bq/m2 (note the change in unit from kg to square meters). Of particular concern were results from within the lifted evacuation advisory zone: Minami Soma (three locations: 600, 260, 160 bq/m2), Tamura (610 Bq/m2), Kawauchi (380、130、39 Bq/m2) and Hirono (220、150、120、76、61 Bq/m2). - Plutonium also detected for the first time outside the plant, however official attitude is to ignore the results, as ‘compared to cesium the quantities are minuscule, therefore the focus will remain on cesium’.

TOKYO — Nuclear workers at the crippled Fukushima power plant raced to inject boric acid into the plant’s No. 2 reactor early Wednesday after telltale radioactive elements were detected there, and the plant’s owner admitted for the first time that fuel deep inside three stricken plants was probably continuing to experience bursts of fission.

The unexpected bursts — something akin to flare-ups after a major fire — are extremely unlikely to presage a large-scale nuclear reaction with the resulting large-scale production of heat and radiation. But they threaten to increase the amount of dangerous radioactive elements leaking from the complex and complicate cleanup efforts, raising startling questions about how much remains uncertain at the plant, the site of the world’s worst nuclear disaster since Chernobyl. The Japanese government has said that it aims to bring the reactors to a stable state known as a “cold shutdown” by the end of the year.

On Wednesday, the plant’s operator, the Tokyo Electric Power Company, said that measurements of gas from inside Reactor No. 2 indicated the presence of radioactive xenon and other substances that could be the byproduct of nuclear fission. The presence of xenon 135 in particular, which has a half-life of just nine hours, seemed to indicate that fission took place very recently.

Radioactive Wolves, the first episode of the 30th season of PBS’s Nature, documents current conditions in the area that was forcibly evacuated following the uncontrolled radioactive material releases caused when the operators at the Chernobyl nuclear power station conducted a poorly planned experiment and blew up their power plant.In the absence of human beings, the remaining creatures seem to be doing just fine. I believe that is because it is hard to teach animals to be afraid of radiation; they do not watch many scary movies or news programs featuring breathless commentators interviewing publicity seeking “experts” whose main claim to fame is a lack of actual nuclear plant operating experience. Even long-lived creatures like catfish and eagles show few signs that they are constantly eating contaminated food from an area that has been officially declared to be unfit for habitation.

It should be difficult for a thinking person to watch this show without asking some of the following questions: If radiation is so dangerous, why doesn’t it seem to affect other mammals? If radiation is so dangerous, why do the plants and animals look so normal and healthy? Is there any logical reason to be more fearful of radiation than other risks? If radiation is not as dangerous as some people claim, why were so many people forced to leave their homes and livelihoods? Who benefits by working so hard to make people afraid of radiation and nuclear energy? A long time ago, I read a lengthy technical article that provided the details of the events leading up to the explosion. It was difficult to imagine how any trained operator could keep moving down the path that was taken without calling a halt to the evolution to ask hard questions and demand adequate responses.

By the end of the article, I was more than a little suspicious that the politically appointed person driving the actions actually wanted to damage the plant. At the time I could not understand why anyone would do such a thing. That was before I realize how financially rewarding it can be for the establishment hydrocarbon industry to put nuclear energy into a negative light and before I understood just how important selling oil and gas to Europe was to the Soviet Union and how important that activity remains for Russia.I have read a few articles recently about efforts in Belarus to resettle parts of the evacuated areas, but information about the progress of those efforts is difficult to find. In the post Fukushima world, it is important to learn as much as we can about the measured long-term effect of radioactive materials released into the environment. Reactor accidents are events worth avoiding, but it is becoming more evident that the actual results are within the limits of the risk that is routinely accepted in many other industries.If that is true, more people should become comfortable with the prospects of using nuclear energy to benefit mankind and to make life more comfortable and prosperous for us all. The reality seems to be that nuclear accidents are not only rare events, but the consequences that result from a rare, but possible, failure are acceptable.

A. Stohl1, P. Seibert2, G. Wotawa3, D. Arnold2,4, J. F. Burkhart1, S. Eckhardt1, C. Tapia5, A. Vargas4, and T. J. Yasunari61NILU – Norwegian Institute for Air Research, Kjeller, Norway2Institute of Meteorology, University of Natural Resources and Life Sciences, Vienna, Austria3Central Institute for Meteorology and Geodynamics, Vienna, Austria4Institute of Energy Technologies (INTE), Technical University of Catalonia (UPC), Barcelona, Spain5Department of Physics and Nucelar Engineering (FEN),Technical University of Catalonia (UPC), Barcelona, Spain6Universities Space Research Association, Goddard Earth Sciences and Technology and Research, Columbia, MD 21044, USAAbstract. On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant (FD-NPP) developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions of two isotopes, the noble gas xenon-133 (133Xe) and the aerosol-bound caesium-137 (137Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site.

This first guess was subsequently improved by inverse modeling, which combined the first guess with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 16.7 (uncertainty range 13.4–20.0) EBq, which is the largest radioactive noble gas release in history not associated with nuclear bomb testing. There is strong evidence that the first strong 133Xe release started very early, possibly immediately after the earthquake and the emergency shutdown on 11 March at 06:00 UTC. The entire noble gas inventory of reactor units 1–3 was set free into the atmosphere between 11 and 15 March 2011. For 137Cs, the inversion results give a total emission of 35.8 (23.3–50.1) PBq, or about 42% of the estimated Chernobyl emission. Our results indicate that 137Cs emissions peaked on 14–15 March but were generally high from 12 until 19 March, when they suddenly dropped by orders of magnitude exactly when spraying of water on the spent-fuel pool of unit 4 started. This indicates that emissions were not only coming from the damaged reactor cores, but also from the spent-fuel pool of unit 4 and confirms that the spraying was an effective countermeasure. We also explore the main dispersion and deposition patterns of the radioactive cloud, both regionally for Japan as well as for the entire Northern Hemisphere. While at first sight it seemed fortunate that westerly winds prevailed most of the time during the accident, a different picture emerges from our detailed analysis

Exactly during and following the period of the strongest 137Cs emissions on 14 and 15 March as well as after another period with strong emissions on 19 March, the radioactive plume was advected over Eastern Honshu Island, where precipitation deposited a large fraction of 137Cs on land surfaces. The plume was also dispersed quickly over the entire Northern Hemisphere, first reaching North America on 15 March and Europe on 22 March. In general, simulated and observed concentrations of 133Xe and 137Cs both at Japanese as well as at remote sites were in good quantitative agreement with each other. Altogether, we estimate that 6.4 TBq of 137Cs, or 19% of the total fallout until 20 April, were deposited over Japanese land areas, while most of the rest fell over the North Pacific Ocean. Only 0.7 TBq, or 2% of the total fallout were deposited on land areas other than Japan.Discussion Paper (PDF, 6457 KB)   Supplement (13 KB)   Interactive Discussion (Open, 0 Comments)   Manuscript under review for ACP   

The world's largest nuclear energy producer, the United States, Tuesday aired its first detailed public examination of whether stronger safety standards are needed in light of Japan's Fukushima Daiichi nuclear disaster.Although the U.S. Nuclear Regulatory Commission (NRC) task force concluded that the sequence of events that caused Japan's crisis was unlikely to recur in the United States, the panel has urged a new focus on preparing for the unexpected.(Related: "How is Japan's Nuclear Disaster Different?)Especially at issue is how to deal with "beyond design-basis" risks, events considered too unlikely to be factored in when the plants were being designed. The U.S. task force recommended that a framework of "extended design-basis" requirements be established for the 104 reactors in the United States. This is especially important, task force member Gary Holahan said, in light of the fact that "many of the older plants might have less robust seismic, flooding, and other features."

Part of the concept of the framework is for the NRC to articulate” expected safety requirements, and to test all plants, no matter their age or design, against that same standard, said Holahan, deputy director of NRC's office of new reactors.The post-Fukushima inspection reports that NRC ordered for all U.S. nuclear power plants provide a window into risks that the task force says the agency should address.

For instance, in their April visit to the oldest U.S. nuclear power plant, Exelon's Oyster Creek, near Toms River, New Jersey, close to the shore, the inspectors noted that if power were lost, emergency venting procedures "could result in hydrogen accumulation in the reactor building." Such a build-up is believed to have caused the explosions at Fukushima Daiichi, which, like Oyster Creek, had boiling water reactors with Mark 1 containment systems. Among the NRC task force's recommendations is that reliable hardened vent designs be required in such reactors. (Fukushima and most of the 31 U.S. boiling water reactors have hardened vent designs; the task force is urging steps to make them more reliable.)Here's a look at some of the other post-Fukushima concerns raised by inspectors at the ten oldest U.S. nuclear power plants.

The destroyed Fukushima nuclear plant in Japan was responsible for the biggest discharge of radioactive material into the ocean in history, a study from a French institute said. The radioactive cesium that flowed into the ocean from the Fukushima Dai-Ichi nuclear plant was 20 times the amount estimated by its owner, Tokyo Electric Power Co., according to the study by the Institute for Radiological Protection and Nuclear Safety, which is funded by the French government. It’s the second report released in a week calling into question estimates from Japan’s government and the operator of the plant that was damaged in the March earthquake and tsunami. Tokyo Electric’s Fukushima station may have emitted more than double the company’s estimate of atmospheric release at the height of the worst civil atomic crisis since Chernobyl in 1986. End Extract http://mobile.bloomberg.com/news/2011-10-31/fukushima-plant-released-record-amount-of-radiation-into-ocean?category=%2Fnews%2Fmostread%2F