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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   

There are many terrific reasons to favor the rapid development of nuclear fission technology.

It is a reliable and affordable alternative to hydrocarbon combustionIt is a technology that can use less material per unit energy output than any other power sourceIt is a technology where much of the cost comes in the form of paying decent salaries to a large number of human beingsIt is a technology where wealth distribution is not dependent on the accident of geology or the force of arms in controlling key production areasIt is an energy production technology where the waste materials are so small in volume that they can be isolated from the environmentIt is a technology that is so emission free that it can operate without limitation in a sealed environment – like a submarineIt is an important climate change mitigation too

Our current economy is built on an industrial foundation that removes about 7-10 billion tons of stored hydrocarbons from the earth’s crust every year and then oxidize that extracted material to form heat, water and CO2 – along with some other nasty side products due to various impurities in the hydrocarbons and atmosphere. The 20 billion tons or so of stable CO2 that we dump into the atmosphere is not disappearing – there are some natural removal processes that were in a rough balance before humans started aggressive dumping, but most of the mass of CO2 that we are pumping into the thin layers of atmosphere that surround the Earth is not being absorbed or used.

Published on May 1, 2012 In this dataset, the simulation from NOAA's HYSPLIT model shows a continuous release of tracer particles from 12-31 March at a rate of 100 per hour representing the Cesium-137 emitted from Fukushima Daiichi. Each change in particle color represents a decrease in radioactivity by a factor of 10. Radioactivity decreases due to removal by rainfall and gravitational settling. Decay is not a factor for Cesium in this short duration simulation compared to its 30 year long-half life. The air concentration would be computed from the particle density so it is only partially related to the color scale. The released particles are followed through the end of April using meteorological data from the 1-degree resolution NOAA global analyses. http://sos.noaa.gov/datasets/Atmosphere/fukushima.html Category Education License Standard YouTube License

Scientists in California are reporting raised levels of radioactive chemicals in the atmosphere in the weeks following the disaster at Japan's Fukushima Daiichi nuclear power plant. The measurements are the latest evidence that the reactors melted down catastrophically.

Researchers at the University of California, San Diego (UCSD), say that radioactive sulfur from the stricken power plant reached California in late March, two weeks after the crisis at Fukushima began. The sulfur is a by-product of emergency procedures taken immediately after the accident. The work is published in the Proceedings of the National Academy of Sciences.

The latest measurements seem to confirm that. For several years, Mark Thiemens, a chemist at UCSD, and his group have been measuring atmospheric levels of a radioactive isotope of sulfur, 35S, which is usually generated by cosmic rays striking argon atoms in the atmosphere. On 28 March, the team detected levels of radioactive sulfur dioxide gas (35SO2) and sulphate aerosols (35SO4-2) that were well above the natural background.

Here, based simplified, are the chemical reactions in the atmosphere, which explain how the Fukushima disaster impacted the Arctic ozone hole.   The cold winter in 2010-2011 produced dense stratospheric clouds over the Arctic, which due to the presence of water promoted chemical reactions with various gases to produce compounds that deplete ozone over the Arctic Circle.   The Arctic ozone hole, that began expanding due to the clouds, radically widened in March and April, coinciding with the Fukushima disaster.

The damaged Fukushima reactors and burning fuel rods released many, many tons of of iodine (a highly-reactive ozone-attacking agent)  and xenon, which soon transformed into xenon fluoride (produced when xenon comes under UV catalysis to combine with fluorine gas in the atmosphere).     Fluorine is abundant over the US Pacific Northwest and Canada. The jet stream carried the iodine and newly-formed XeFl compounds in a northeasterly direction, crossing into the Arctic circle and looping back down over Greenland, Scandinavia and European Russia. This exactly accounts for the oblong shape and direction of the expanded ozone hole.

From the Mainichi newspaper...   Researchers Report Unprecedented Ozone Loss In Arctic   10-3-11   TSUKUBA, Japan (Kyodo) -- The depletion of the Arctic ozone layer reached an unprecedented level in early 2011 and was "comparable to that in the Antarctic," an international research team said Sunday in the online version of the British science magazine Nature.   "For the first time, sufficient loss occurred to reasonably be described as an Arctic ozone hole," said the nine-country team, including Hideaki Nakajima of the National Institute for Environmental Studies in Tsukuba in Ibaraki Prefecture.

France's CEREA has the simulation map of ground deposition of cesium-137 from the Fukushima I Nuclear Power Plant accident on its "Fukushima" page. It not only shows Japan but also the entire northern Pacific Rim, from Russian Siberia to Alaska to the West Coast of the US to the entire US. According to the map, the US, particularly the West Coast and particularly California, may be more contaminated with radioactive cesium than the western half of Japan or Hokkaido. It looks more contaminated than South Korea or China. Canada doesn't look too well either, particularly along the border with US on the western half.

From CEREA's Fukushima page: Atmospheric dispersion of radionuclides from the Fukushima-Daichii nuclear power plant CEREA, joint laboratory École des Ponts ParisTech and EdF R&D Victor Winiarek, Marc Bocquet, Yelva Roustan, Camille Birman, Pierre Tran Map of ground deposition of caesium-137 for the Fukushima-Daichii accident. The simulation was performed with a specific version of the numerical atmospheric chemistry and transport model Polyphemus/Polair3D. The parametrisations used for the transport and physical removal of the radionuclides are described in [1,2,3,4]. The magnitude of the deposition field is uncertain and the simulated values of deposited radionuclides could be significantly different from the actual deposition. In particular, the source term remains uncertain. Therefore, these results should be seen as preliminary and they are likely to be revised as new information become available to better constrain the source term and when radionuclides data can be used to evaluate the model simulation results.

The page also has the animated simulation of cesium-137 dispersion from March 11 to April 6, 2011. If the Japanese think they are the only ones who have the radiation and radioactive fallout from the accident, they are very much mistaken, if the simulation is accurate. (Meteorological institutes and bureaus in Austria, Germany, and Norway all had similar simulation maps.) Radioactive materials spewed out of Fukushima I Nuke Plant went up and away on the jet stream, reaching the other side of the Pacific. When the fallout from explosions (March 14, 15) reached the US West Coast, it came with an unusually heavy rainfall in California.

The disaster at the Fukushima Daiichi nuclear plant in March released far more radiation than the Japanese government has claimed. So concludes a study1 that combines radioactivity data from across the globe to estimate the scale and fate of emissions from the shattered plant. The study also suggests that, contrary to government claims, pools used to store spent nuclear fuel played a significant part in the release of the long-lived environmental contaminant caesium-137, which could have been prevented by prompt action. The analysis has been posted online for open peer review by the journal Atmospheric Chemistry and Physics.

Andreas Stohl, an atmospheric scientist with the Norwegian Institute for Air Research in Kjeller, who led the research, believes that the analysis is the most comprehensive effort yet to understand how much radiation was released from Fukushima Daiichi. "It's a very valuable contribution," says Lars-Erik De Geer, an atmospheric modeller with the Swedish Defense Research Agency in Stockholm, who was not involved with the study. The reconstruction relies on data from dozens of radiation monitoring stations in Japan and around the world. Many are part of a global network to watch for tests of nuclear weapons that is run by the Comprehensive Nuclear-Test-Ban Treaty Organization in Vienna. The scientists added data from independent stations in Canada, Japan and Europe, and then combined those with large European and American caches of global meteorological data.

Stohl cautions that the resulting model is far from perfect. Measurements were scarce in the immediate aftermath of the Fukushima accident, and some monitoring posts were too contaminated by radioactivity to provide reliable data. More importantly, exactly what happened inside the reactors — a crucial part of understanding what they emitted — remains a mystery that may never be solved. "If you look at the estimates for Chernobyl, you still have a large uncertainty 25 years later," says Stohl. Nevertheless, the study provides a sweeping view of the accident. "They really took a global view and used all the data available," says De Geer.

The misinformation on thorium is highly promoted by the nuclear industry and various companies that want investment dollars for thorium reactors and fuel

One myth is that thorium is safe. Thorium-232 has a half life of 14 billion years (billions, not millions). Thorium-232 is also highly radiotoxic, with the same amount of radioactivity of uranium and thorium, thorium produces a far higher dose in the body. If someone inhaled an amount of thorium the bone surface dose is 200 times higher than if they inhaled the same amount of uranium. Thorium also requires longer spent fuel storage than uranium. With the daughter products of thorium like technetium‐99 with a half life of over 200,000 years, thorium is not safe nor a solution to spent fuel storage issues.

Another myth is that thorium reactors can run at atmospheric temperatures, in order to produce power they must be run differently and would not be at atmospheric temperatures. Many of the thorium reactors use liquid sodium fluoride in the reactor process. This material is highly toxic and has its own series of risks. The creation of thorium fuels is also not safer than creating uranium fuels. Thorium poses the same nuclear waste and toxic substance problems found in mining and fuel milling of uranium.

The Environmental Protection Agency recommends reverse osmosis water treatment to remove radioactive isotopes that emit beta-particle radiation. But iodine-131, a beta emitter, is typically present in water as a dissolved gas, and reverse osmosis is known to be ineffective at capturing gases. A combination of technologies, however, may remove most or all of the iodine-131 that finds its way into tap water, all available in consumer products for home water treatment.

When it found iodine-131 in drinking water samples from Boise, Idaho and Richland, Washington this weekend, the EPA declared: An infant would have to drink almost 7,000 liters of this water to receive a radiation dose equivalent to a day’s worth of the natural background radiation exposure we experience continuously from natural sources of radioactivity in our environment.” But not everyone accepts the government’s reassurances. Notably, Physicians for Social Responsibility has insisted there is no safe level of exposure to radionuclides, regardless of the fact that we encounter them naturally:

There is no safe level of radionuclide exposure, whether from food, water or other sources. Period,” said Jeff Patterson, DO, immediate past president of Physicians for Social Responsibility. “Exposure to radionuclides, such as iodine-131 and cesium-137, increases the incidence of cancer. For this reason, every effort must be taken to minimize the radionuclide content in food and water.” via Physicians for Social Responsibility, psr.org No matter where you stand on that debate, you might be someone who simply prefers not to ingest anything that escaped from a damaged nuclear reactor. If so, here’s what we know: Reverse Osmosis The EPA recommends reverse osmosis water treatment for most kinds of radioactive particles. Iodine-131 emits a small amount of gamma radiation but much larger amounts of beta radiation, and so is considered a beta emitter:

Japan will seek to halve the amount of radiation in residential areas around the Fukushima No. 1 nuclear plant and cut children's daily radiation dose by 60 percent over the next two years, according to an emergency decontamination policy document.

The plan is to be endorsed Friday by a government task force dealing with the nuclear crisis triggered by the March 11 earthquake and tsunami

The government under the plan will take responsibility for securing final disposal sites for contaminated soil but will stress the need for temporarily storage locally.

Soon after Japan's triple disaster, I suggested that an official cover-up of a nuclear-weapons program hidden inside the Fukushima No.1 plant was delaying the effort to contain the reactor meltdowns. Soon after the tsunami struck, the Tokyo Electric Power Company reported that only three reactors had been generating electricity on the afternoon of March 11.. (According to the initial report, these were the older GE-built reactors 1,2 and 6.). Yet overheating at five of the plant's six reactors indicated that two additional reactors had also been operating (the newer and more advanced Nos. 3 and 4, built by Toshiba and Hitachi). The only plausible purpose of such unscheduled operation is uranium enrichment toward the production of nuclear warhead

On my subsequent sojourns in Japan, other suspicious activities also pointed to a high-level cover-up, including systematic undercounts of radiation levels, inexplicable damage to thousands of imported dosimeters, armed anti-terrorism police aboard trains and inside the dead zone, the jamming of international phone calls, homing devices installed in the GPS of rented cars, and warning visits to contacts by government agents discouraging cooperation with independent investigations. These aggressive infringements on civil liberties cannot be shrugged off as an overreaction to a civil disaster but must have been invoked on grounds of national security.

One telltale sign of high-level interference was the refusal by science equipment manufacturers to sell isotope chromatography devices to non-governmental customers, even to organizations ready to pay $170,000 in cash for a single unit. These sensitive instruments can detect the presence of specific isotopes, for example cesium-137 and strontium-90. Whether uranium was being enriched at Fukushima could be determined by the ratio of isotopes from enriched weapons-grade fissile material versus residues from less concentrated fuel rods.

Using the supercomputer program called SPRINTARS, researchers at Kyushu University and Tokyo University created the simulation of how radioactive materials from Fukushima I Nuclear Power Plant may have dispersed throughout the northern hemisphere. The researcher say their simulation fit the actual measurements. It was published in the Scientific Online Letters on the Atmosphere (SOLA) under the title "A numerical simulation of global transport of atmospheric particles emitted from the Fukushima Daiichi Nuclear Power Plant" in June. You can read the paper at this link (PDF file). You can also view the animation, here, and the press release in Japanese here.

Their simulation also shows, like France's CEREA, radioactive materials from March 14/15 release reached the west coast of North America on March 18. The researchers attribute the rapid dispersion of radioactive materials from Fukushima to the unusually strong jet stream. Also, on March 14/15, there was a low pressure on the east cost of Japan, which created a strong updraft that lifted the radioactive materials to the jet stream. The relative scale is set with the density of radioactive materials at Fukushima I Nuke Plant as 1. By the time it reached North America, it was between 0.000001 and 0.00000001.

9/6 (5:26pm): We tested a topsoil sample and a dried manure sample from the Sacramento area. The manure was produced by a cow long before Fukushima and left outside to dry; it was rained on back in March and April. Both samples showed detectable levels of Cs-134 and Cs-137, with the manure showing higher levels than the soil probably because of its different chemical properties and/or lower density. In addition, a soil sample from Sonoma county was tested. This sample had been collected in late April but we had not had the chance to test it until now.

One interesting feature of the Sacramento and Sonoma soil samples is that the ratio of Cesium-137 to Cesium-134 is very large — approximately 17.6 and 5.5, respectively. All of our other soil samples until now had shown ratios of between 1 and 2. We know from our air and rainwater measurements that material from Fukushima has a cesium ratio in the range of approximately 1.0 to 1.5, meaning that there is extra Cs-137 in these two soil samples. The best explanation is that in addition to Fukushima fallout, we have also detected atmospheric nuclear weapons testing fallout in these soils. Weapons fallout contains only Cs-137 (no Cs-134) and is known to be present in older soils (pre-1963). Both of these samples come from older soils, while our samples until this point had come from newer soils. This direct comparison between Fukushima fallout and atmospheric weapons fallout in these soils shows that the fallout from Fukushima in Northern California is significantly less than the amount of Cs-137 that still remains from weapons testing, which has had nearly 50 years to disperse and decay.

I have been rereading a 1982 book by Bertrand Goldschmidt titled “The Atomic Complex: A Worldwide Political History of Nuclear Energy.”

The two self-assigned homework projects are as part of a reflective effort to understand more about how human society moved from a period of optimism based on a vision of “Atoms for Peace” to a period where someone reading the advertiser supported press would believe that sensible people would logically consider giving up the whole technology out of fear of radiation and its health consequences.One of the hopeful lessons I have learned so far is that the initial conditions of our current fight to defend and expand the safe use of atomic energy are far different from those that faced the people engaged in the earliest battles against a well organized opposition to nuclear technology development. We have a much better chance of success now than we did then – and there are several reasons why that is true.

One condition that is vastly different is the ability of nuclear professionals to have their voices heard. No longer are most people who understand nuclear energy isolated in small communities with few media outlets. In the 1970s, a large fraction of nuclear professionals were located near remotely sited national laboratories or power stations. Today, though many still work at national labs or in small market communities like Lynchburg, VA, we are all globally connected to a vast network on the Internet. We have Skype, YouTube and blogs. Some of us know that major decision makers and journalists read or listen to our words on a regular basis. We are no longer shy about responding to misinformation and unwarranted criticism.

Experts predict that the closure of nuclear plants in Germany will bring about a steady increase of gas, petroleum and coal in its thermoelectric uses, which will be reflected in the increase of 26 million tons per year of greenhouse gases, contributing to global warming.

Thermoelectric power use emits CO2, a principal greenhouse gas that, along with others, produces acid rain. All of these send thousands of tons of ash, residues from coal and heavy metals, and even concentrates amounts of radioactive material into the atmosphere. For their part, modern nuclear reactors emit almost no contaminants into the air, although they periodically emit small quantities of radioactive gases. Their residues are smaller in volume (to the order of a million times) and are better controlled than those of thermoelectric power.

Pros and Cons