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What is actually going to take place at the Fukushima No. 1 Nuclear Power Plant, where word is that the four reactors that were crippled in the Great East Japan Earthquake and tsunami will eventually be decommissioned? The Ministry of Economy, Trade and Industry's Nuclear and Industrial Safety Agency (NISA) defines "decommissioning" as the process of removing spent fuel from reactors and dismantling all facilities. Ultimately, the site of a decommissioned reactor is meant to be reverted into a vacant lot.

In 1996, the then Japan Atomic Energy Research Institute (JAERI) -- now the Japan Atomic Energy Agency (JAEA) -- finished decommissioning its Japan Power Demonstration Reactor. The decommissioning process of the Tokai Nuclear Power Plant in the Ibaraki Prefecture village of Tokai began in 1998 and is set to end in fiscal 2020, while the No. 1 and No. 2 nuclear reactors at the Hamaoka Nuclear Power Plant in the Shizuoka Prefecture city of Omaezaki are slated for decommissioning by fiscal 2036. Around the world, only around 15 nuclear reactors have thus far been dismantled.

The standard decommissioning process entails six major steps: 1. Remove spent fuel rods, 2. Remove radioactive materials that have become affixed to reactor pipes and containers, 3. Wait for radiation levels to go down with time, 4. Dismantle reactors and other internal vessels and pipes, 5. Dismantle the reactor buildings, and 6. Make the site into a vacant lot.

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:

An experiment to test the power of sunflowers to absorb toxic radiation has failed to prove effective near the site of the nuclear disaster at Fukushima, Japan.  The Asahi Shimbun reports that the sunflowers removed only .05 percent of the radioactive cesium in the ground, while the  removal of just over an inch (3 centimeters) of topsoil along with grass removed up to 97 percent of the radioactive cesium. It was hoped that sunflowers would concentrate radioactive waste and could then be removed more easily than the wholesale “scraping” of soil and compost that it seems will  be required. In the meantime scientists are studying ways to decontaminate the forests near the nuclear accident site. According to the Japan Times, the prefecture (county) where the plant is located is 70% forested, and efforts to date have focused on decontaminating urban areas. Removing the contaminated soil and other material from the forest requires such extreme removal methods that the forest’s ecosystem will be seriously damaged.

Whether the radiation is removed by scraping soil or removing plant matter, the radioactive waste still needs to be safely stored. The government has not yet selected a permanent storage site for the tons of soil and debris that needs to be sequestered. Anti-Nuclear Protests Hit Tokyo

The Japanese public’s trust in nuclear power is clearly ebbing, as tens of thousands of citizens took to the streets of Tokyo today (Monday) to protest nuclear power. Police estimated the crowd at 20,000 (while organizers claimed more) as protesters carried signs saying “Sayonara Nuclear Power” to urge the government to eliminate nuclear power from the nation’s energy grid.  Nuclear accounted for 30 percent of Japan’s energy use prior to the Fukushima incident. There have been energy shortages as 30 of the country’s 54 reactors have been taken off line to enable inspections. Large businesses have been asked to take measures to conserve energy, such as adjusting thermostats, varying schedules around peak demand and cutting back on overtime. It has been six months since three of the Fukushima nuclear plant’s six reactors experienced meltdowns following a catastrophic earthquake and tsunami. Surrounding air, soil and water was contaminated and 100,000 residents were forced to evacuate.

NGO "FoE Japan (Friends of Earth Japan) did its own survey of radiation contamination in Watari District in Fukushima City with the help from Professor Tomoya Yamauchi of Kobe University. Watari District has high radiation levels throughout the district, but the national government has so far refused to designate anywhere in the district as "evacuation recommended" area.If the government designate an area as such, the government has to pay for the relocation cost. As the result, the designation in other cities like Date City has been very arbitrary and spotty, rendering the whole exercise worthless. Often, the residents are simply moved to the other parts of the same city with slightly lower radiation.

Judging from Professor Yamauchi's air radiation survey (in Japanese), this particular location looks like the one that had 23 microsieverts/hour radiation at 1 centimeter off the surface of the dirt in the roadside drain. Professor Yamauchi hypothesized that radioactive cesium from surrounding mountains and forests washes down the drain after the rain, and naturally gets concentrated in the dirt.

In my communication with Professor Yamauchi, I asked if the decontamination as currently practiced in Fukushima works at all, given the non-result in Watari District which he surveyed. He said the spot decontamination like removing the dirt and sludge is useless as radioactive materials simply come from somewhere else, so the district-wide decontamination including the surrounding mountains would be necessary to "decontaminate" in the true sense of the word - to remove radioactive materials, not reduce.

While readings of radiation in the air have returned to pre-3/11 levels in most areas of Japan — not including areas close to the plant and the so-called hot spots — the contamination of soil, which affects the food chain, could pose a long-term health risk, experts say. Iodine-131, cesium-134 and cesium-137 were released in large quantities by the nuclear plant, and if they are accumulated in the body, they could cause cancer.

Kunikazu Noguchi, lecturer at Nihon University and an often-quoted expert on radiological protection, assures that consumers need not worry too much about any produce on the market, because at present, radiation levels in most vegetables, meat, dairy and other foods, even those from Fukushima Prefecture, are far below the government's safety limits and often undetectable. But for consumers concerned about the few incidents of tainted food slipping through the government checks (such as the beef from cattle that had been fed with tainted straw in Fukushima, which was shipped nationwide in July), or families with small children, Noguchi suggests a simple way to minimize their radiation exposure through food: rinse it.

rinsing the food well before cooking, preferably with hot water, and/or boiling or stewing it, a large portion of radioactive elements can be removed. In his book, published in Japanese in mid-July, "Hoshano Osen kara Kazoku wo Mamoru Tabekata no Anzen Manyuaru" ("The Safety Manual for Protecting Your Family From Radiation Contamination"), Noguchi offers tips on how to prepare food, item by item, so consumers can reduce their radiation intake at home.

TEPCO announced on September 9 that 6 workers entered the reactor building of Reactor 3 at Fukushima I Nuclear Power Plant, and installed a water gauge to measure the amount of contaminated water in the basement. According to the company, the radiation exposure of the 6 workers was between 0.33 to 5.26 millisieverts. The measurement using the water gauge is set to start on or after September 12.

... TEPCO also disclosed the plan to start removing the debris from the upper floors of Reactors 3 and 4. The work will start in Reactor 3 on September 10, and it will start in Reactor 4 within this month. Upper floors of Reactors 3 and 4 are littered with damaged ceiling panels and exterior wall panels, and it is hoped that the spread of radioactive materials will be suppressed by removing the debris.

Removing the debris will stir up the radioactive materials instead of suppressing them, won't it? Not to mention exposing the workers to an inadvertent 10-plus sieverts/hour super hot spot, as it happened near the exhaust stack between Reactors 1 and 2?From the tweets by the worker at Fukushima I Nuke Plant, it is evident that TEPCO is fast running out of money (to spend on the accident, apparently not on its retiring executives) and carbon-based workers to do further work. The worker also tweeted a week or so ago that the construction people were active, already clearing debris in Reactor 4.

A roadmap toward decommissioning of the damaged Fukushima Daiichi nuclear power plant indicates that the removal of melted nuclear fuel rods at the plant may begin in 10 years. NHK has obtained the mid- and long-term roadmap which was presented when officials from the operator of the Fukushima plant, government officials in charge of nuclear safety, and manufacturers of nuclear reactors met last week. The draft roadmap drawn up by the government's Nuclear Safety Commission and Tokyo Electric Power Company says they tentatively set a target date to begin removing fuel rods that melted and fell to the bottom of the reactor. The work is considered to be the most important phase in the decommissioning process. The roadmap indicates that removal will start in 2021 if technology essential for the work has been developed before that. The timeline is believed to have been set based on measures taken following the 1979 Three Mile Island accident in the United States. But unlike the US case, as reactor containment vessels were damaged at the Fukushima complex, they need to be fixed and filled with water. The roadmap shows that reactor buildings could be finally demolished and cleared away after the removal of melted fuel rods is completed, and that it will possibly take dozens of years.

Radioactive materials from the damaged Fukushima No. 1 nuclear plant reached the Kanto region mainly via two routes, but they largely skirted the heavily populated areas of Tokyo and Kanagawa Prefecture, an expert said. Relatively high levels of radioactive cesium were detected in soil in northern Gunma and Tochigi prefectures and southern Ibaraki Prefecture after the Fukushima No. 1 nuclear power plant was damaged by the March 11 Great East Japan Earthquake and tsunami. But contamination was limited in Tokyo and Kanagawa Prefecture, where 22 million people live. Hiromi Yamazawa, a professor of environmental radiology at Nagoya University, said the first radioactive plume moved through Ibaraki Prefecture and turned northward to Gunma Prefecture between late March 14 and the afternoon of March 15.

Large amounts of radioactive materials were released during that period partly because the core of the No. 2 reactor at the Fukushima No. 1 plant was exposed. "The soil was likely contaminated after the plume fell to the ground with rain or snow," Yamazawa said, adding that western Saitama Prefecture and western Tokyo may have been also contaminated. Rain fell in Fukushima, Tochigi and Gunma prefectures from the night of March 15 to the early morning of March 16, according to the Meteorological Agency. The second plume moved off Ibaraki Prefecture and passed through Chiba Prefecture between the night of March 21 and the early morning of March 22, when rain fell in a wide area of the Kanto region, according to Yamazawa's estimates.

He said the plume may have created radiation hot spots in coastal and southern areas of Ibaraki Prefecture as well as around Kashiwa, Chiba Prefecture. Yamazawa said the plume continued to move southward, without approaching Tokyo or Kanagawa Prefecture, probably because winds flowed toward a low-pressure system south of the Boso Peninsula. "It rained slightly because the low-pressure system was not strong," said Takehiko Mikami, a professor of climatology at Teikyo University. "Contamination in central Tokyo might have been more serious if (the plume) had approached more inland areas." According to calculations by The Asahi Shimbun, about 13,000 square kilometers, or about 3 percent of Japan's land area, including about 8,000 square kilometers in Fukushima Prefecture, have annual exposure levels of 1 millisievert or more.

The turbine hall at the shut down Bradwell nuclear power plant in Essex, UK, is being demolished as part of the plant's decommissioning. The hall is the largest single building on the site. Meanwhile, an innovative process is being used to clean the site's used fuel pool.   The Bradwell site hosts two 125 MWe Magnox gas-cooled reactors, which operated between 1962 and 2002.

The turbine hall - about the size of a football pitch and some 15 metres tall - was originally constructed in the 1950s and used to house the plant's nine turbine generators.

Work has already been carried out to strip off the metal sheeting covering the building to reveal its main structure. Ancillary buildings on the Bradwell site - including the auxiliary turbine hall, the main control room, the water treatment plant and the battery room - have already been demolished.   Over 100 tonnes of dangerous asbestos has been removed from the hall, while more than 6000 tonnes of metal has been removed and sent for recycling.

Contaminated soil a concern at Los Alamos lab, Reuters, July 11, 2011: [...] crews at the Los Alamos National Laboratory have begun removing contaminated soil from nearby canyons out of a concern that flash flooding could wash toxins into the Rio Grande [that supplies drinking water for Santa Fe and many other communities] officials said on Monday. [...] The soil in the canyons above Los Alamos National Laboratory, the linchpin of American’s nuclear weapons industry, contains materials with trace amounts of radiation [...] Over the weekend, about 1,200 cubic yards of contaminated soil was removed primarily from two canyons — Los Alamos and Pajarito — that run through lab property, [ Fred deSousa, spokesman for the lab's environmental control division] said.

An Assessment of Los Alamos National Laboratory Waste Disposal Inventory, Radioactive Waste Management Associates, November 2009:

Since the beginning of its operations LANL has disposed of millions of gallons of radioactive and hazardous waste throughout the laboratory grounds and in the canyons that surround the laboratory. [...]

expected to take more than 30 years to decommission crippled reactors at the Fukushima No. 1 Nuclear Power Plant, and workers tasked with the difficult mission would have to venture into "uncharted territory" filled with hundreds of metric tons of highly radioactive nuclear fuel,

After the expert committee of the Japan Atomic Energy Commission (JAEC) compiled a report on procedures to decommission the No. 1 to 4 reactors at the Fukushima No. 1 Nuclear Power Plant on Dec. 7, the actual work is expected to move into high gear after the turn of the year. As in the case of the 1979 Three Mile Island accident, the workers would try to remove melted nuclear fuel after shielding radiation with water, a technique called a "water tomb." But the work would have to be done in a "territory where humans have not stepped into before," said a senior official of Tokyo Electric Power Co. (TEPCO), the operator of the troubled Fukushima nuclear power station. The work is so difficult that it is expected to take more than 30 years to finish decommissioning the reactors.

Up to about 5,000 millisieverts per hour of radiation -- lethal levels -- have been detected in the reactor building of the No. 1 reactor.

according to Sankei Shinbun, who has been unabashedly pro-nuclear energy and in favor of dispersing radioactive materials throughout Japan via the disaster debris to share in the "pain".The paper has an article about the meeting between the Ministry of the Education officials and the heads of the municipalities within the 20-kilometer radius "no entry zone" where the heads of the municipalities received the information from the Ministry about their lot - whether they can return after the decontamination work by the national government or not.

But that isn't the interesting part of the article.At the end of the article, there is a separate section that the newspaper writes about what "decontamination" is, according to the Ministry of the Education:

Decontamination: "It is like a cleaning job of stubborn dirt or stains" (Ministry of the Environment senior officials). Basically, it relies on manpower, using hand tools like shovels and scrubbing-brushes. According to the guideline published at the end of last year by the Ministry of the Environment, what can be easily removed, such as dead leaves, is to be removed by hand. The roofs are to be washed down by high-pressure washers, and the concrete surface such as the entrance of a house is to be scrubbed by scrubbing-brushes and deck brushes. As for the grassland and the soil where radioactive materials have penetrated, the surface is to be removed using shovels or diggers. Workers must pay attention not to get exposed to radioactivity by wearing the protective gear.

Radioactive fallout from the crippled Fukushima No. 1 nuclear plant has caused widespread fear, prompting the government in August to adopt basic targets for decontamination efforts in and around Fukushima Prefecture.

But the government's plan falls short and efforts should focus in particular on residential areas with more aggressive decontamination measures and goals, including reducing current radiation levels by 90 percent, two radiation experts said when interviewed by The Japan Times. "I really doubt their seriousness (about decontamination)," said radiation expert Tomoya Yamauchi, a professor at the Graduate School of Maritime Sciences at Kobe University.

Areas with radiation exposure readings representing more than 20 millisieverts per year have been declared no-go zones, and the government has shifted the focus of its decontamination plan to areas with radiation readings, based on an annual accumulative amount, of between 20 millisieverts and more than 1 millisievert, with the goal of reducing the contamination by 50 to 60 percent over two years. Decontamination efforts by humans, however, are expected to only yield a reduction of 10 to 20 percent. Nature, including the impact of rain, wind and the normal degradation of the radioactivity of cesium-134, whose half-life is roughly two years, is assumed to do the rest, thus reaching the best-case scenario of cutting the contamination by 60 percent.

A nuclear power plant that was shut down after an earthquake struck central Virginia Tuesday had seismographs removed in 1990s due to budget cuts. U.S. nuclear officials said that the North Anna Power Station, which has two nuclear reactors, had lost offsite power and was using diesel generators to maintain cooling operations after an 5.9 earthquake hit the region.

Japan faces the prospect of removing and disposing 29 million cubic metres of soil contaminated by the world's worst nuclear crisis in 25 years from an area nearly the size of Tokyo, the environment ministry said in the first official estimate of the scope and size of the cleanup. Six months after the March 11 earthquake and tsunami triggered reactor meltdowns, explosions and radiation leaks at Fukushima Daiichi nuclear power plant on Japan's northeast coast, the size of the task of cleaning up is only now becoming clear. Contaminated zones where radiation levels need to be brought down could top 2,400 square km (930 square miles), sprawling over Fukushima and four nearby prefectures, the ministry said in a report released on Tuesday.

If a 5 cm (2-inch) layer of surface soil, likely to contain cesium, is scraped off affected areas, grass and fallen leaves are removed from forests, and dirt and leaves are removed from gutters, it would amount to nearly 29 million cubic metres of radioactive waste, the document showed. This would be is enough to fill 23 baseball stadiums with a capacity of 55,000 spectators, and the government must decide where to temporarily store such waste and how to dispose of it permanently.

Japan has banned people from entering within a 20 km (12 mile) radius of the plant, located about 240 km (150 miles) northeast of Tokyo and owned by Tokyo Electric Power Co . Some 80,000 people were forced to evacuate. The government aims to halve radiation over two years in places contaminated by the crisis, relying on both the natural drop in radiation as time passes and by human efforts.

Gemma Reguera at Michigan State University leads a team that found the normal digestive processes of a common type of bacteria – known as Geobacter – can reduce levels of uranium waste. She spoke with EarthSky:

geobacter

She said these bacteria don’t make radioactive material less radioactive. But they do immobilize it by converting it into a solid that’s more easily contained – so we can remove it and store it safely. Her group found that, when Geobacter come into contact with free-floating uranium – uranium dissolved in water, let’s say – the bacteria zap the uranium with small blasts of electricity. They do this naturally, as part of their digestive processes. This electricity causes the uranium to mineralize – in other words, they turn the uranium into something like a rock. Radioactive material is much less potent in this solid form, Reguera said, and easier to remove from the environment. She said:

Iitate is located 45km (28 miles) from the Fukushima Dai-ichi nuclear power plant hit by a tsunami on March 11th this year. In the mountains above the town, the forests are turning the colour of autumn. But their beauty is deceptive. Every time a gust of wind blows, Mr Sato says it shakes invisible particles of radioactive caesium off the trees and showers them over the village. Radiation levels in the hills are so high that villagers dare not go near them. Mr Sato cannot bury his father’s bones, which he keeps in an urn in his abandoned farmhouse, because of the dangers of going up the hill to the graveyard.

Iitate had the misfortune to be caught by a wind that carried radioactive particles (including plutonium) much farther than anybody initially expected after the nuclear disaster. Almost all the 6,000 residents have been evacuated, albeit belatedly, because it took the government months to decide that some villages outside a 30km radius of the plant warranted special attention. Now it offers an extreme example of how difficult it will be to recover from the disaster.

That is mainly because of the enormous spread of radiation. Recently the government said it needed to clear about 2,419 square kilometres of contaminated soil—an area larger than greater Tokyo—that received an annual radiation dose of at least five millisieverts, or over 0.5 microsieverts an hour. That covered an area far beyond the official 30km restriction zone (see map). Besides pressure- hosing urban areas, this would involve removing about 5cm of topsoil from local farms as well as all the dead leaves in caesium-laden forests.