The Fukushima nuclear power plant was opened to journalists for the first time; See below for numerous links to related stories.
There appears to be very high levels of radiation at Fukushima plant reactor #3, and at either reactors 1 and 3, or both, nuclear fission may have been occurring in the melted down remains. Ideally, once a plant is turned off, i.e., control rods inserted etc. etc., the state of "criticality" is stopped and there is no more fission, or at least, only a small background level. But, if a nuclear power plant's core melts down, nuclear material can re-accumulate in some uncontrolled manner in the wreckage beneath the plant or in lower areas of a reactor containment vessel, and critical mass can be re-attained. This apparently has been detected over the last few weeks at Fukushima. This is evident from the presence of Xenon-135, a product of nuclear fission with a half life of just over 9 hours.
However, TEPCO appears to be making adjustments to the definition of the term "criticality" so this problem is expected to go away soon. (You will remember that some time ago when it became apparent that TEPCO would be unable to effect a true "cold shutdown" of the melted down reactors, the definition of "cold shutdown" was changed. Now, there is discussion of the meaning of the term "criticality.") Also, TEPCO reassures us that the detection of the products of "spontaneous fission" is not really a new phenomenon. Rather, they just started to be able to detect this accidental nuclear process. It has presumably been going on all along (which could go a long way to explaining why it has been impossible to obtain a "cold shutdown" of the reactors without having to resort to redefining "cold").
Of increasing concern is the amount of evidence that people, including some school children, nuclear plant workers, and others have been found to have internal exposure, meaning particles of nuclear material were breathed in or ingested. In a possibly related move, the upper limits of contamination for food is being lowered significantly. One rescue worker who was found to have been internally exposed has died and some are suggesting that there is a link.
One report indicates that about 79 percent of the fallout from Fukushima ended up in the ocean, 19% has been deposited on the land in Japan, about 2% on other land surfaces mainly in Asia and North America. The report indicates that about twice as much Cesium 137 was released at Fukushima than had bee previously reported. Another report indicates that measurable amounts of Iodine-131 have been found in several European countries, of uncertain origin.
Speaking of contamination, have a look at this discussion of bird brains and radiation at Chernobyl.
Robotic exoskeletons are being developed to help the workers work harder - there are ~3,000 people working there every day. It is interesting to observe over these months since the meltdowns how many procedures and technologies are being invented and deployed for the very first time, as though the nuclear power industry actually, really, truly believed that nothing could ever go wrong. Had the possibility of a major disaster such as this been considered earlier, not only would TEPCO and others have been more prepared, but also, the costs may have been manged better.
Speaking of cost, there is talk of recalculating the cost of nuclear energy - internalizing waste costs and accident costs when planning plants. Interesting idea, and utterly surprising that this has never occurred to anyone before. It turns out that nuclear energy is fairly expensive. Floridians are upset over two or three billion dollars of state funds being used to upgrade a nuclear power plant plant; TEPCO has asked for and will get a trillion yen. It adds up.
The Japanese Genkai reactor has restarted, and this is the first restart of a nuke plant shut down for technical problems in Japan since the massive Fukushima meltdown. The technical problem was caused by a screw-up that was, in turn, caused by using a faulty operation manual. Perhaps the instructions were written originally in English and translated poorly into Japanese. In any event, it is telling that a) Nuclear industry lies and cheats to get a major plant that should not have been built constructed where it should not be; b) plant melts down causing worst nuclear power disaster ever; c) Other plants start to resume operations d) within weeks, another plant is shut down because of a bad photocopy job in a manual.
Oh yes, of course we can trust the Nuclear Power Industry to get it right.
NHK asked plant operators if they'd been cyber attacked and many said yes, but that they had not been compromised. And of course, the would never lie. Later it was reported that sensitive data was leaked through these attacks, including design plans, etc.
And now, it is time for Ana's Feed of all the latest Fukushima and other Nuclear Power related news:
2,600 Bq/Liter Tritium in Water Being Sprayed in the Plant Compound -EX-SKF, Oct. 27
- On October 24, TEPCO quietly released the analysis of the water being sprayed in the plant compound, supposedly for fire and dust suppression.
- The water comes from the basements of Reactors 5 and 6, and is treated, apparently, by the system that uses reverse osmosis. TEPCO assures us the water is safer than the seawater cleared for ocean bathing, though it does exceed the WHO standard.
- One notable nuclide that does remain after the RO treatment is tritium (H3). From TEPCO's handout for the press (10/24/2011):
80 to 120 Microsieverts/Hr Bush in Koriyama City, Fukushima -EX-SKF, Oct. 27
- It's been over 7 months since the Fukushima I Nuclear Power Plant accident started, and it does look like natural concentration of radioactive materials may be happening in eastern Japan.
- 57.5 microsieverts/hour radiation from the soil in the city-owned land in Kashiwa City, Chiba sounded extraordinarily high when first reported, but maybe not so.
- Fukushima Chuo Television (FCT) reported that the radiation level near the ground in a bush right by the railroad station was found to be 80 to 120 microsieverts/hour in Koriyama City, Fukushima Prefecture.
To Flee or Not to Flee, That Was the Question -All Things Nuclear, Oct. 27
- During an event sponsored by the American Association for the Advancement of Science on Monday, October 24, Dr. Gregory Jaczko, Chairman of the Nuclear Regulatory Commission (NRC), defended his March 16 decision to recommend the evacuation of American citizens out to 50 miles from the stricken Fukushima-Daiichi nuclear plant in Japan. It was not the first and likely not the last time the Chairman will have to defend his decision.
- I wont use the luxury of hindsight to judge whether his decision was right or wrong. But it did greatly lessen a years-old concern Ive had regarding the NRCs decision-making process.In fall of 2001, the NRC staff drafted an order that would require the Davis-Besse nuclear plant to shut down by the end of the year for safety inspections. Figure 1 shows one of the slides used by the NRC staff when briefing NRC senior managers about the need for the safety inspections. The NRC staff concluded: There is not reasonable assurance of adequate protection of public health and safety.
Panel lowers limit of radiation in food -Japan Times, Oct. 28
- Health minister Yoko Komiyama announced Friday that the government will lower the allowable amount of radiation in food products from 5 millisieverts per year to 1, but some experts are puzzled.
- Permanent limits for various categories of food will be set based on recommendations submitted Thursday by the government's food panel.
- The current limit of 500 becquerels per kilogram of radiation for meat, fish and vegetables is also expected to be lowered by about one-fifth in April.
- Citing findings from various studies, the food safety panel concluded Thursday that a cumulative dose of 100 millisieverts or more throughout one's lifetime poses significant health risks.
Kashiwa govt wants help with hotspot -Mainichi News, Oct. 28
- The Kashiwa municipal government said last Friday that radiation of 57.5 microsieverts per hour had been detected about 30 centimeters below the surface of the plot of land. Its subsequent examination of soil at the location detected radioactive cesium of up to 276,000 becquerels per kilogram.
- Airborne radiation of 2 microsieverts per hour was recorded one meter above the ground–the same level detected in Iitatemura, Fukushima Prefecture, which was designated part of the expanded evacuation zone after the beginning of the crisis at the Fukushima No. 1 nuclear power plant.
- On Sunday, the Education, Culture, Sports, Science and Technology Ministry said Kashiwa's hotspot was likely caused by the Fukushima crisis.
- "It's difficult to find a company to decontaminate [the site] given the extremely high level of radiation," a city government official said. "The situation is more than we can handle as a local government."
Kansai Electric submits stress test results -NHK, Oct. 28
- A Kansai Electric official, Masanori Kataoka, visited the government's Nuclear and Industrial Safety Agency on Friday to deliver the test results on its No.3 reactor at Ohi nuclear plant in Fukui Prefecture.
- The utility says a reactor maker's simulation showed that the reactor could withstand an earthquake 1.8 times the intensity and a tsunami 4 times the height of the estimated maximums for the area.
Financial fallout from Fukushima disaster embittering victims -Irish Times, Oct. 28
- IN AUTUMN last year, Katsuzo Shoji (75) was quietly farming rice, vegetables and a small herd of cattle in the picturesque village of Iitate. Today, he lives in a two-room temporary house 35km (22 miles) away with his wife Fumi (73).
- His herd has been slaughtered, his farm abandoned to weeds. He is unlikely to earn a working income again, let alone return alive to the home that has been in his family since the 1880s.
- Shojis story is just one of at least 80,000 from the irradiated prefecture of Fukushima, home to the disabled Daiichi nuclear power plant, which has been leaking radiation since the March 11th earthquake and tsunami knocked out its cooling system.
Japanese group develops handheld decontaminator -NHK, Oct. 28
- The machine was created by researchers from the Wakasa Wan Energy Research Center in Fukui Prefecture, central Japan.
- The device uses laser beams moving at a high speed to scrape off radioactive substances attached to the surface of pipes and other objects at nuclear power plants. The dust is then collected inside the machine.
- The researchers say that, since only the surface is scraped off, the machine generates one thousand times less radioactive waste than conventional methods.
- The device is about 30 centimeters high and wide, and 40 centimeters long. The team says it is the world's first portable radiation decontaminator.
Fuel retrieval at Fukushima to start in 10 years -NHK, Oct. 28
- The report says decommissioning will start with repairing the containment vessels of the No.1 to No.3 reactors, where meltdowns occurred.
- The vessels will then be filled with water to block radiation released from the melted fuel.
- The commission also plans to start moving spent fuel rods from pools at the No.1 to No.4 reactors to another pool in the plant within 3 years. This will take place after the reactors achieve a state of cold shutdown.
- The report projects that the decommissioning will take more than 30 years to complete.
TEPCO to request 12 bil. dollars in public aid -NHK, Oct. 28
- Sources say TEPCO is expected to incur nearly 580 billion yen, or about 7.6 billion dollars, in net losses for the business year through next March.
- The major reasons they cite are sharp rises in fuels costs for thermal power generation and the expenses associated with the accident at the Fukushima Daiichi nuclear power plant.
- The firm plans to ask for around 11.8 billion dollars in assistance from a government-backed institution to help pay compensation to people and businesses affected by the nuclear accident.
Is Nuclear Energy a Fuel with a Future? -HuffPost, Oct. 28
- Nuclear advocates argue that it is a low-carbon alternative to fossil fuels that can provide more baseload power than renewables. Opponents respond that even if you resolve daunting radioactive waste, environmental risk and security issues, exorbitant construction costs remain. Studies by the California Energy Commission (PDF) and Mark Cooper (PDF), Senior Fellow at Yale University's Institute for Energy and the Environment, have shown that the costs of building future nuclear capacity are even higher.
- Despite buzz about a "nuclear renaissance," the industry has had trouble attracting private investment, and relies almost exclusively on government subsidies and support. By contrast, the private renewables market has soared over the last several years, with the UN Environment Programme reporting that global investments in green energy topped $211 billion in 2010, up 32 percent from 2009, and a staggering 540 percent since 2004.
Fukushima women peacefully protest nuclear -youtube, Oct. 28
TEPCO seeks 1 tril. yen for N-compensation -Yomiuri, Oct. 29
- Tokyo Electric Power Co. filed an application Friday with a government-backed body for about 1 trillion yen in funds to finance compensation payments in connection with the nuclear crisis at the utility's Fukushima No. 1 power plant.
- TEPCO and the Nuclear Damage Liability Facilitation Fund, which was jointly established in September by the government and power utilities with nuclear reactors, on the same day finalized the company's emergency business plan.
Stress test shows Oi reactor tough enough -Yomiuri, Oct. 29
- KEPCO became the first utility to submit results of a stress test to the government since the tests became mandatory for all reactors in July in the wake of the crisis at the Fukushima No. 1 nuclear power plant operated by Tokyo Electric Power Co.
- According to KEPCO's report, the Oi No. 3 reactor can withstand an earthquake with 1,260 Gal, 1.8 times larger than the assumed 700 Gal. A Gal is a unit of acceleration of gravity.
- The reactor and its pipes can withstand a tsunami 11.4 meters high, comfortably exceeding the assumed height of 2.85 meters, the report said.
- Even if all alternate current power sources are lost, it will be possible to keep cooling the reactor core for 16 days.
- Emergency safety measures carried out on the agency's orders after the Fukushima No. 1 plant accident increased the reactor's ability to stand up to serious disasters, it said.
80 volunteers help scrub radiation -Japan Times, Oct. 29
- Around 80 volunteers from across the country gathered Saturday in the city of Fukushima to begin decontaminating areas affected by radioactive materials emitted by the Fukushima No. 1 nuclear plant.
- The municipal government distributed gloves, masks and dosimeters to the volunteers before the cleanup work, which includes weeding and picking up fallen leaves, got under way.
- Fukushima has secured the services of around 240 volunteers, who will carry out decontamination work every weekend in highly contaminated areas in the city.
Ocean Absorbed 79 Percent Of Fukushima Fallout -Forbes, Oct. 29
- About 19 percent of airborne fallout from the Fukushima nuclear disaster was deposited in Japan, and only about 2 percent made it to other land areas in Asia and North America, according to a study published this week by the European Geosciences Union. The bulk was absorbed by the Pacific Ocean.
- Opponents of nuclear energy have seized on the European study because it describes the total release at Fukushima as massive. It finds that twice as much cesium 137 was released at Fukushima than originally reported.
Excessive cesium detected in greenhouse-grown mushrooms in Fukushima -Mainichi News, Oct. 30
- The prefectural government has asked the city of Soma and dealers to stop shipment of the mushrooms, and a local agricultural cooperative has begun recalling them after they were found to contain 850 becquerels of cesium per kilogram, exceeding the 500-becquerel limit set by the state.
- The farm in question has grown the mushrooms on beds made of a mixture of woodchips and nutrients, and the woodchips used in them are suspected to have been contaminated with the radioactive substance, according to the local government. The mushroom beds were sold by the Soma agricultural cooperative.
- The farm has shipped 1,070 100-gram packages of shiitake mushrooms since Monday, and they are believed to have been sold at nine supermarkets in the prefecture from Tuesday. No other shiitake mushrooms produced by the farm have entered the market, it said.
Radioactive soil to be disposed of 30 yrs after interim storage -Mainichi News, Oct. 30
- The Japanese government said Saturday it will seek the final disposal of soil and other waste contaminated with radioactive substances emitted from the crippled Fukushima Daiichi nuclear power plant within 30 years after they are collected in a storage facility in Fukushima Prefecture.
- What the government calls an "interim" storage facility should be in use within around three years, with an estimated storage capacity of 15 million to 28 million cubic meters and a total site area of about 3 to 5 square kilometers.
- According to the basic idea, decontamination activities are expected to start in full-swing from January and local governments are asked to place removed soil and other contaminated substances at temporary storage spaces for around three years until the storage facility is prepared.
Can nuclear power be part of the solution? -AlJazeera, Oct. 30
- As the unfolding nuclear disaster in Japan has shown, the costs of cleanup after a nuclear meltdown are borne in large part by national governments and taxpayers rather than by industry. Paying for cleanup is just one of many hidden costs of nuclear energy that make judging the value of nuclear power difficult. Many countries, including the United States, are rushing to build a new generation of nuclear power plants to reduce carbon emissions.
- However, the disaster in Japan should force us to take into account the full costs of nuclear power (and other energy sources). Here we propose that all forms of energy incorporate their full costs (including climate impacts, the risk of accidents, and the safe disposal of waste) so that their true value to society can be revealed and better decisions made.
Locals get their say on nuclear power plan -Republican Eagle, Oct. 30
- Local leaders joined people from around the region and country Friday to voice their thoughts on the future of nuclear energy in America.
- Gathered in Minneapolis, legislators, city and tribal leaders, corporate representatives and others shared their reactions to a draft report from the presidents Blue Ribbon Commission on Americas Nuclear Future outlining suggestions for nuclear waste management.
- Prairie Island Indian Community and Red Wing officials had the chance to offer perspectives as nearby and host communities to the Prairie Island nuclear plant.
An official drinks water from Fukushima plant -NHK, Oct. 31
- A senior government official drank a glass of water from the Fukushima Daiichi nuclear plant on Monday in an apparent effort to demonstrate its safety.
- On October 7th, Tokyo Electric Power Company began spraying about 70 tons of purified water over the compound at its Fukushima nuclear plant every day. The utility uses the water after removing radioactive substances and salt from the contaminated water that has accumulated in the basements of the Numbers 5 and 6 reactor buildings.
- When asked if he could wipe away public concern about the water, Sonoda said he drank the water because he was asked to, but he does not think his act can ensure the water's safety.
Fukushima officials leave for Chernobyl -NHK, Oct. 31
- A delegation from Fukushima Prefecture is en route to 2 former Soviet republics to investigate how they have dealt with lingering radiation from the 1986 Chernobyl nuclear accident.
- Fukushima University organized the 8-day trip to Ukraine and Belarus. More than 30 medical experts and municipal officials are participating, including Yuko Endo, the mayor of Kawauchi, a village near the disabled Fukushima Daiichi nuclear power plant.
Local Fukushima residents seek compensation for decontamination gear, costs -Mainichi News, Oct. 31
- Residents battling radioactive contamination in and around their houses, who purchased high-pressure water sprayers, are seeking compensation for their independent decontamination campaigns.
- The residents are frustrated because such water sprayers bought by individuals are not covered by a compensation scheme carried out by Tokyo Electric Power Co. (TEPCO), the operator of the crippled Fukushima No. 1 Nuclear Power Plant. Furthermore, the central government stipulated in late September that the state will shoulder decontamination costs when local governments conduct such decontamination work.
- But the residents reacted angrily to the government policy, saying, "It is natural for individual expenditures for decontamination work to be compensated in light of the cause" of radioactive contamination. Municipalities concerned are joining the residents in asking the central government to change its policy.
Bidders receive documentation in multibillion tender to build 2 more Czech nuclear reactors -Washington Post, Oct. 31
- The move is part of an energy plan to dramatically increase the countrys nuclear power production which could also sour relations with some of the countrys neighbours, especially Germany that has decided to shelve its nuclear plans following Japans nuclear disaster earlier this year.
- Austria has said it will try to stop the Czechs since the plant is near its border.
- Three bidders U.S.-based Westinghouse Electric Co., a subsidiary of Japans Toshiba Corp., Frances state-owned nuclear engineering giant Areva SA and a consortium led by Russias Atomstroyexport are competing.
Vietnam, Japan nuclear project intact despite Fukushima -Reuters, Oct. 31
- Japan and Vietnam on Monday reaffirmed their plan to build a nuclear power plant in the Southeast Asian country using Japanese technology, even as Tokyo still struggles to put the world's worst nuclear accident in 25 years under control.
FirstEnergy Finds More Cracks at Davis-Besse Nuclear Power Plant -Bloomberg, Oct. 31
- FirstEnergy Corp. said an investigation of damage to the concrete outer shell of its Davis-Besse nuclear power plant unearthed additional hairline cracks.
- The sub-surface cracks on the shield building dont affect the facilitys structure integrity or safety, Akron, Ohio-based FirstEnergy said in a letter to investors today. The company said the 913-megawatt reactor, shut since Oct. 1, will resume producing power in late November.
- FirstEnergy shut the plant to install a new reactor vessel head three years earlier than previously planned. The U.S. Nuclear Regulatory Commission in 2005 imposed a $5.45 million fine, its largest ever, for FirstEnergys failure to discover corrosion had eaten a hole in a prior vessel head.
A Giant New Plutonium Complex at Los Alamos -HuffPost, Oct. 31
- …or, "How to spend $6 billion, create 600 jobs, and prop up the most unproductive sector of the military industrial complex for another generation."
- Despite President Obama's campaign rhetoric of a world without nuclear weapons, despite the recent catastrophe at Japan's Fukushima complex, and despite the new START nuclear arms control treaty between the U.S. and Russia last February, it seems the desire among our leaders for nuclear power and nuclear weaponry remains as strong today as it was at the height of the Cold War. What's just as disturbing, though, is the disregard our government shows for any input from its citizenry – pro or con.
Special Report on the Nuclear Accident at the Fukushima Daiichi Nuclear Power Station -Institute of Nuclear Power Operations, Nov.
China Doubles Down on Nuclear Power -IEEE, Nov.
- Beijing has launched an aggressive plan to decarbonize China's economy by pushing nuclear and renewable energy to 15 percent of energy consumption by 2020, up from 9.5 percent last year. Nuclear generating capacity would rise to over 80 gigawatts from the 11.3 GW currently in place. As a result, analysts expect China to meet its environmental goal for 2020: to reduce carbon emissions per yuan of economic output by 40 percent compared with 2005 levels.
- To meet its nuclear numbers, China has embarked on the world's biggest reactor building program. Beijing has standardized its nuclear juggernaut around two pressurized water reactor designs: the Chinese/French CPR-1000, designed in the 1990s, and Westinghouse Electric's AP1000, designed in the 2000s. The country is turning both types out at high speed. According to the World Nuclear Association, 14 reactors were operating as of September, and 26 more were under construction. China's Ministry of Environmental Protection has said that 100 reactors may be feeding the grid by 2020. "They are not just building nuclear power plants. They are building an entire industry," says Chi-Jen Yang, a technology policy expert at Duke University's Center on Global Change.
- Nevertheless, the Fukushima disaster has highlighted the risks of the nation's aggressive nuclear build-out. In Fukushima's wake Chinese leaders put new reactor projects on hold while they reviewed the safety of existing ones. Officials concerned by a potential shortfall of trained reactor operators and inspectors suggested trimming China's 2020 goal for more than 80 GW nuclear capacity by 10 GW or so. Experts also worry that corrupt management of the build-out could affect the safety of China's reactors. As Yang puts it: "If everything is done well, the risks should be low. But we don't know if everything is done correctly."
24 Hours at Fukushima -IEEE, Nov.
- Millions of people had to die on highways, for example, before governments forced auto companies to get serious about safety in the 1980s. But with nuclear power, learning by disaster has never really been an option. Or so it seemed, until officials found themselves grappling with the world's third major accident at a nuclear plant. On 11 March, a tidal wave set in motion a sequence of events that led to meltdowns in three reactors at the Fukushima Dai-ichi power station, 250 kilometers northeast of Tokyo.
- Unlike the Three Mile Island accident in 1979 and Chernobyl in 1986, the chain of failures that led to disaster at Fukushima was caused by an extreme event. It was precisely the kind of occurrence that nuclear-plant designers strive to anticipate in their blueprints and emergency-response officials try to envision in their plans. The struggle to control the stricken plant, with its remarkable heroism, improvisational genius, and heartbreaking failure, will keep the experts busy for years to come. And in the end the calamity will undoubtedly improve nuclear plant design.
- True, the antinuclear forces will find plenty in the Fukushima saga to bolster their arguments. The interlocked and cascading chain of mishaps seems to be a textbook validation of the "normal accidents" hypothesis developed by Charles Perrow after Three Mile Island. Perrow, a Yale University sociologist, identified the nuclear power plant as the canonical tightly coupled system, in which the occasional catastrophic failure is inevitable.
Ammonia Leak Reported At San Onofre Nuclear Power Plant -CBS L.A., Nov. 1
- Southern California Edison has contained an ammonia leak at the San Onofre nuclear power plant in San Diego County.
- Orange County Sheriffs officials say that the leak was detected at about 3:10 p.m. Tuesday, prompting officials to issue an alert.
- The leak occurred in a steam system used to drive the stations turbines, SCE said.
- SCE reported that the approximately 30 gallons of leaked ammonia is being collected in a basin underneath the tank that was designed for that purpose.
1.7 Millisievert External Radiation in One Month for 3rd Grader in Fukushima City: "Will Not Affect Health" Says City Official -EX-SKF, Nov. 1
- Fukushima City announced the result of the readings of the glass badges worn by children and pregnant women in the city for the month of September, and the highest reading was 1.7 millisievert external radiation exposure in one month for a 3rd-grader in an elementary school. Her two brothers were also found with high radiation reading off their badges.
- The city says, "That level of radiation does not affect health".
Reactor in Japan Restarts, a First Since the Tsunami -NYT, Nov. 1
- A nuclear reactor in western Japan began starting back up on Tuesday after a months hiatus, the first reactor in the country closed for any reason to win approval from a local government to resume operations since the Fukushima nuclear disaster.
- The reactor at the Genkai plant was started up around 11 p.m. local time and was set to reach 100 percent generating capacity on Wednesday, Kyushu Electric said. But the reactors run will be brief: the same reactor must be stopped in mid-December for routine maintenance.
Schoolgirl in Fukushima exposed to high level of radiation in September -Mainichi News, Nov. 2
- A young girl was found to have been exposed to 1.7 millisieverts of radiation in September due to the ongoing nuclear crisis at the Fukushima No. 1 nuclear power plant, city authorities have revealed.
- The Fukushima Municipal Government announced on Nov. 1 that a third-year elementary school girl in the city was exposed to the high level of radiation in September alone, with her three brothers also having been exposed to 1.4 to 1.6 millisieverts of radiation in the same month. Their residence was located close to a highly-radioactive spot, and the family has since moved outside Fukushima Prefecture.
- The city has collected the individual dosimeters from 36,478 residents for analysis and found that 99 percent of them had been exposed to no more than 0.3 millisieverts of radiation in September. Apart from the four children, no other residents in the area were found to have been exposed to over 1 millisievert of radiation.
Cesium in pollen not viewed as health risk -Japan Times, Nov. 2
- 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.
Tepco Detects Nuclear Fission at Fukushima Station -Bloomberg, Nov. 2
- Tokyo Electric Power Co. detected signs of nuclear fission at its crippled Fukushima atomic power plant, raising the risk of increased radiation emissions. No increase in radiation was found at the site and the situation is under control, officials said.
- The company, known as Tepco, began spraying boric acid on the No. 2 reactor at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it may have found xenon, which is associated with nuclear fission, while examining gases taken from the reactor, according to an e-mailed statement today.
- Given the signs, its certain that fission is occurring, Junichi Matsumoto, a general manager at Tepco who regularly talks to the media, told reporters in Tokyo today. Theres been no large-scale or sustained criticality and no increase in radiation, he said.
Xenon suggests possible nuclear fission -NHK, Nov. 2
- Professor Koji Okamoto of the University of Tokyo Graduate School says substances from melted fuel that could undergo fission are probably scattered around, but are unlikely to react.
- He says, however, that neutrons from radioactive materials could react with the uranium fuel and other substances.
- The professor also referred to a plan by the government and TEPCO to achieve a state of cold shutdown by the end of the year. He says that if fission reactions are not under control, it would not be a cold shutdown.
- Okamoto says TEPCO must locate the melted fuel inside and outside the reactor in order to prevent further reactions.
TEPCO: Reactor may have gone critical -NHK, Nov. 2
- The utility says it has not found any significant change in temperature and pressure of the reactor, and that large-scale criticality did not occur.
- TEPCO says the reactor's cooling process is continuing and that the firm expects to achieve cold shutdown at the plant this year as planned. But the utility also says it wants to take a close look at the situation of the plant's No.1 and 3 reactors.
Reactor 2 CV Gas Analysis on November 2: Slight Increase in Xe-131m, Xe-135, 100-Fold Increase in Krypton-85 from November 1 -EX-SKF, Nov. 2
- From TEPCO's handout for the press (11/2/2011), from November 1 to November 2:
TEPCO: Radiation levels unchanged -NHK, Nov. 2
- 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.
- Readings at 8 other monitoring posts on Wednesday were also the same as Tuesday.
Temperature, pressure unchanged in No.2 reactor -NHK, Nov. 2
- The company says the temperature at the bottom of the reactor was 76 degrees Celsius as of 5 AM on Wednesday. That was down 1.4 degrees from 24 hours earlier.
- The reactor's pressure gauge registered 0.007 megapascals at 5 AM on Wednesday, down one part per thousand from the same time on Tuesday.
Fears of Fission Rise at Stricken Japanese Plant -NYT, Nov. 2
- Nuclear workers at the crippled Fukushima power plant raced to inject boric acid into the plants No. 2 reactor early Wednesday after telltale radioactive elements were detected there, and the plants owner admitted for the first time that fuel deep inside three stricken reactors 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.
Radioactive materials detected in Tokyo Bay -NHK, Nov. 2
- Waste water discharged into Tokyo Bay from a cement plant has been found to contain radioactive cesium at much higher levels than the government-set limit for disposal.
- The plant in Chiba Prefecture, east of Tokyo, uses ash from incinerators in the prefecture to produce cement.
- The Chiba government says the plant operator checked waste water discharged from the plant into Tokyo Bay once in September and once in October.
- It found radioactive cesium at levels of 1,103 becquerels per kilogram, and 1,054 becquerels per kilogram respectively.
- The levels are 14 to 15 times higher than the limit set by the country's Nuclear Safety Commission.
Nuclear safety body used inspection criteria drafted by nuclear fuel firm -Mainichi News, Nov. 2
- The only legally mandated, independent nuclear industry inspection body in Japan copied nuclear fuel inspection criteria directly from documents provided by the company making the fuel, the Mainichi has discovered.
- The documents, obtained by the Mainichi through repeated official information requests, show that the Japan Nuclear Energy Safety Organization (JNES) copied an inspection manual verbatim from materials it ordered Global Nuclear Fuel Japan Co. to create. Global Nuclear Fuel is one of the firms subject to JNES checks.
- Except for the cover and first page, the JNES manual and the Global Nuclear Fuel document were identical, even down to the page format and font.
Subsidizing nuclear plants in Florida runs counter to capitalism -St. Petersburg Times, Nov. 2
- It's time to drink the Tallahassee Kool-Aid.
- That's the only way we can possibly understand how our state leadership claiming to be big fans of the free market system can bless a state law that lets power companies like Progress Energy and Florida Power & Light make their customers pre-pay the costs of billion-dollar projects that may or may not ever happen.
- Last month, the automatons at the Florida Public Service Commission approved rules requiring customers of our two largest electric utilities to pay $282 million next year to upgrade nuclear plants and build new ones, even if such projects never happen.
- Of that $282 million, $86 million will be paid by Progress Energy Florida customers. The charge will help pay some of the early costs for two proposed Levy County nuclear units and for adding capacity to an existing nuclear plant at Crystal River. This is the same plant Progress Energy broke two years ago trying a do-it-yourself repair. Cost to fix? $2.5 billion.
Rachel Maddow reports on an assortment of energy-related scandals, including a litany of alarming headlines from the nuclear industry -MSNBC, Nov. 3
NRC: No functional damage caused by earthquake at North Anna nuclear reactor -WTVR, Nov. 2
- More than 300 people attended the Nuclear Regulatory Commission's (NRC) public meeting about the North Anna nuclear power station Tuesday night in Louisa County.
- The commission shared its assessment of the nuclear power plant, which has been shut down after it was rocked by a powerful earthquake in August.
- The review found cracks caused by the 5.8-magnitude quake, which was greater than what the reactors were built to withstand. But the NRC said that it found no functional damage that would prevent the plant from safely restarting.
- Some residents disagreed with the findings and said they were "concerned the NRC and Dominion will put profits over safety."
- NRC officials said they will likely issue a final recommendation next week which will allow the reactors to be restarted.
Minor criticality suspected at Fukushima plant's No. 2 reactor -Yomiuri, Nov. 3
- Xenon 133 and xenon 135 are radioactive substances generated when nuclear fission reactions take place.
- The substances were found Tuesday in gas from the reactor containment vessel, Junichi Matsumoto, acting director of TEPCO's Nuclear Power and Plant Siting Division, said at a press conference.
- Xenon 133 has a half-life of about five days, while xenon 135's is about nine hours. Because the two substances have very short half-lives, a small-scale fission reaction is likely to have taken place within the reactor, he said.
- "As the reactor's cooling is progressing, this finding will not have a major impact on the situation," Matsumoto said.
Minister reprimands NISA chief for tardy reporting of xenon detection at Fukushima plant -Mainichi News, Nov. 3
- The head of Japan's Nuclear and Industrial Safety Agency (NISA) was issued a stern reprimand on Nov. 2 for tardiness in delivering news to the government that the No. 2 reactor at the crippled Fukushima No. 1 nuclear plant may have briefly reached criticality.
- Chief Cabinet Secretary Osamu Fujimura revealed at a news conference the same day that Minister of Economy, Trade and Industry Yukio Edano had reprimanded NISA chief Hiroyuki Fukano for failing to report the incident to both himself and the Prime Minister's Office until almost a day after it occurred.
TEPCO retracts criticality call -NHK, Nov. 3
- The Tokyo Electric Power Company, or TEPCO, said on Thursday that the small amount of xenon-135 it detected in gas taken from the reactor's containment vessel was the result of the spontaneous nuclear fission of radioactive curium-242 and -244. The two substances are contained in nuclear fuel.
- The amount of xenon-135 detected almost matched the amount that would have been produced if the radioactive curium in the fuel had undergone spontaneous fission.
- TEPCO says a criticality event would have resulted in higher levels of xenon concentration.
Shortcomings in nuclear safety assessment found -NHK, Nov. 3
- The organization in charge of assessing the safety of Japan's nuclear plants has admitted it allowed nuclear fuel rods to pass quality checks using a faulty manual.
- The manual was borrowed from the Japanese manufacturer of the rods.
- The Japan Nuclear Energy Safety Organization conducted the checks in 2008 on 4 sets of fuel rods for reactors.
- The government-backed organization says it approved 3 of the 4 sets even though the manual said the rods were 3 to 5 centimeters shorter than the actual length of 4 meters.
- It says the examiners failed to notice the mistakes as they did not closely check the manual beforehand.
Faker of Nuclear Reactor Records Gets Probation -ABC News, Nov. 3
- An electrician charged with falsifying inspection records at an unfinished nuclear reactor in Tennessee was sentenced Thursday to two years of probation and community service after he apologized for causing any nuclear fears.
- "I would like to apologize to all the residents who now sleep less securely as a result of my actions," Matthew Correll told U.S. District Judge Curtis L. Collier. "I wish I could explain to them they have nothing to fear from nuclear plants in their backyards."
- Correll, 31, was charged with falsifying reports while working in August 2010 at the Watts Bar Unit 2 reactor, the only site in the nation where a commercial reactor is now under construction.
- Prosecutors said he lied about measuring the diameter of cables designed to provide electric power to operate equipment, including safety systems, in the reactor containment structure at the plant in Spring City between Knoxville and Chattanooga.
- A court filing shows Correll was part of a crew working in an area where an asbestos suit and respirator had to be worn and temperatures exceeded 100 degrees. The filing said the records were falsified on the spur of the moment when Correll was told to "hurry up and get it done."
Building a Nuclear Power Plant on a Fault Still Not a Great Idea -Mother Jones, Nov. 3
- When the East Coast was rocked by an earthquake this summer, there was a momentary bout of concern about a Virginia nuclear power plant that sat right on the fault line. The 5.8 quake was stronger than what the North Anna plant was designed to withstand, and the reactors had to be shut down. The Nuclear Regulatory Commission is still in the process of deciding whether they should be turned back on.
- The watchdogs at the Project on Government Oversight are asking NRC Chairman Gregory Jaczko to release records related to the plant before a decision about reopening it is made. The group has requested records from plant owner Dominion, but were told that a lot of those records are sealed and housed at the University of Virginia's library. POGO included with itsb letter a 34-year-old memo from the Department of Justice that indicates that the plant's original owners knew that they were building it on a fault line as far back as 1970, but hid that from regulators at the time.
- The memo, from May 1977, was the conclusion of an investigation into whether criminal charges should be brought against VEPCO for concealing this info. It notes that the plant's original owner, Virginia Electric Power Company, along with engineering contractors the company hired, tried to cover up the fact that a fault had been found under the site in 1970. The company had already invested $730 million in the plant, and didn't want the plant's ability to get a license to operate compromised. From the memo:
Municipalities increasingly unwilling to accept quake debris -Mainichi News, Nov. 3
- The number of municipalities that have accepted or are considering whether to accept debris from areas ravaged in the March 11 disaster stands at 54, although 572 expressed willingness to do so in April, the Environment Ministry said Wednesday.
- The debris to be disposed of is from Iwate and Miyagi prefectures, with Fukushima Prefecture excluded, but the growing reluctance among the municipalities apparently reflects their concerns that the debris may contain radioactive materials from the crippled Fukushima Daiichi nuclear power plant.
- It estimates that the debris from Iwate and Miyagi totals around 20.5 million tons. The debris has been collected and stored at multiple temporary storage sites. The debris from Fukushima Prefecture, home to the Fukushima complex, is in principle to be disposed of within the prefecture.
- On Wednesday, workers began transporting 30 tons of debris to Tokyo by rail from the Pacific coastal city of Miyako, Iwate. The first train carrying the debris will arrive in Tokyo on Thursday.
Science far from conclusive on low-level radiation risks -Japan Times, Nov. 3
- The March 11 nuclear accident at the Fukushima No. 1 plant has transformed what used to be a long-standing academic debate into an urgent issue for millions of ordinary people: Will long-term exposure to low-level radiation cause any health problems?
- Experts have long been at odds over whether low-level radiation doses of less than 100 millisieverts are damaging.
- Following are questions and answers on the effect of low-level radiation on human health:
Restarted Genkai unit produces power -Japan Times, Nov. 3
- If all runs smoothly, the plant's No. 4 reactor is expected to be back to normal operation Friday, despite opposition from local residents.
- It was the first time since the start of the nuclear crisis at the Fukushima No. 1 power plant in March that a utility has restarted a reactor that went offline due to a technical problem.
- The reactor shut down automatically Oct. 4 due to an abnormality in its steam condenser that emerged after repairs were carried out using a faulty manual.
70 percent in Japan want end to nuclear power -NHK, Nov. 4
- 24 percent of respondents said all nuclear power plants should be shut down and 42 percent said the number should be reduced.
- 23 percent said the existing facilities should be maintained and 2 percent said they want more nuclear plants.
- 49 percent of respondents said they are very afraid of another nuclear accident and 37 percent are worried to a certain extent.
Shareholders to seek money from TEPCO managers -NHK, Nov. 4
- Tokyo Electric Power Company shareholders are poised to launch court procedures and demand that the utility's current and former management return more than 14 billion dollars to the firm.
- About 30 shareholders plan to file a class-action lawsuit against roughly 60 executives who worked at TEPCO over the past 2 decades.
- The investors say they will take legal action if the company refuses to demand that the executives return the large sum of money.
Japan Starts Bailout of Tepco After Fukushima Disaster Causes More Losses -Bloomberg, Nov. 4
- Tokyo Electric Power Co. won approval for a 900 billion yen ($11.5 billion) bailout from the government after the Fukushima nuclear catastrophe to avert bankruptcy and start paying compensation for the crisis.
- Trade and Industry Minister Yukio Edano approved the support after the company known as Tepco committed to cutting 7,400 jobs and 2.5 trillion yen in costs. The utility forecast an annual loss of 600 billion yen, its second since the March earthquake and tsunami wrecked its Fukushima nuclear plant.
Govt to study ways to confirm lack of criticality -NHK, Nov. 4
- Hosono said xenon was detected not because of new developments, but due to detailed radiation monitoring by the Tokyo Electric Power Company.
- He also said he supports the utility's view that xenon was produced through spontaneous fission, not sustained fission, or criticality.
- Hosono said a precondition for putting the plant's reactors into a cold shutdown is ensuring that the accident will no longer escalate. He added that an absence of criticality is one way to achieve such a state.
Find out true reactor conditions -Japan Times, Nov. 4
- Although more than seven months have passed since the start of the nuclear fiasco, clearly the reactor has not yet been stabilized. Tepco's plan to achieve "cold shutdown" of the Nos. 1, 2 and 3 reactors by the end of this year may face difficulty.
- The fact that Tepco cannot deny the possibility of criticality irrespective of its scale is a grave situation. The conditions are similar in the Nos. 1, 2 and 3 reactors. It is thought that nuclear fuel in them melted and has collected in the bottom of both the pressure and containment vessels.
- Tepco should make serious efforts to accurately grasp the conditions of nuclear fuel inside the reactors.
Radioactivity in Fukushima children's urine -NHK, Nov. 5
- A medical consulting firm in Tokyo says radioactive material has been detected in the urine of 104 children in Fukushima Prefecture, the site of the troubled Fukushima Daiichi nuclear power plant.
- RHC JAPAN collected urine from children aged 6 or younger in Minamisoma City to check for possible internal exposure.
- Those checks were done at the request of parents of preschool children. Tests being carried out by local governments only cover elementary school students and older.
- Of 1,500 samples that have been analyzed so far, 7 percent contain radioactive cesium.
Fukushima: Far From Any Stable Shutdown -The Big Picture, Nov. 5
Cleaning up Japans nuclear mess: The twilight zone -The Economist, Nov. 5
- IT IS another world beyond the roadblocks stopping unauthorised traffic from entering the 20km (12.5-mile) exclusion zone around the Fukushima Dai-ichi nuclear power plant. The few people inside are dressed in ghostly white protective suits. Town after town was abandoned after March 11th, and spiders have strung webs across the doorways. An old ladys russet wig lies in the road, lost perhaps as she took flight after the earthquake, tsunami and nuclear disaster. Outside the Night Friend nightclub in Tomioka, 9km from the nuclear plant, this correspondent was confronted by an ostrich with a feral glint.
- Journalists are supposedly barred from the exclusion zone, though sympathetic evacuees, many furious with the authorities about their state of limbo, help provide access. Some of the 89,000 displaced residents have been given one-day permits to go home and each collect a box of valuables. To an outsider, the size and recent prosperity of the abandoned communities is striking. As well as the rice paddies, now overrun with goldenrod, are large businesses and well-built schools for hundreds of children.
- Patrol cars stop passing vehicles. The police are particularly vigilant in preventing unauthorised people getting near the stricken plant, owned by Tokyo Electric Power (Tepco), Japans biggest utility. The air of secrecy is compounded when you try to approach workers involved in the nightmarish task of stabilising the nuclear plant. Many are not salaried Tepco staff but low-paid contract workers lodging in Iwaki, just south of the exclusion zone.
Tepco Finds Dangerous Level of Radiation at Fukushima Station -Bloomberg, Nov. 6
- Tokyo Electric Power Co. found a dangerous level of radiation at its wrecked Fukushima nuclear plant, eight months after the March 11 earthquake and tsunami that caused the worst atomic crisis in 25 years.
- Workers at the company usually called Tepco detected 620 millisieverts of radiation an hour on the first floor of Reactor 3 on Nov. 3, the highest level found in that unit, it said.
Video of Packbot Cleaning Reactor 3's 1st Floor in Extremely High Radiation -EX-SKF, Nov. 6
- Utterly meaningless endeavor as far as I am concerned. What good would cleaning the gas in the Containment Vessel do, when just outside the CV you measure 620 millisieverts/hr radiation? Something more deadlier than xenon and krypton is outside the CV, and the company is willing to risk both non-carbon based worker (Packbot) and carbon-based co-workers in order to keep up the appearance that everything is under control at the plant.
- Nonetheless, here's the effort by Packbot on November 2, when it removed the junk out of the way, as released by TEPCO on November 5. Actually, TEPCO used 3 Packbots on November 2 and 3 for the work, according to Jiji Tsushin (11/5/2011):
Documents show heavy Entergy lobbying on Vt. nuke -CBS News, Nov. 6
- Entergy Corp. heavily lobbied multiple federal agencies last spring as it unsuccessfully pleaded with them to join its lawsuit against the state of Vermont's efforts to close the Vermont Yankee nuclear plant, internal Nuclear Regulatory Commission documents show.
- The emails, letters and other documents, obtained from the NRC by The Associated Press after a Freedom of Information Act request, also show NRC Chairman Gregory Jaczko being coached by the agency's lawyers to scale back remarks he had been making saying the agency was unlikely to intervene in the Entergy lawsuit.
- And they indicate the NRC's five commissioners at least planned to meet with Entergy representatives in early June, something they told a U.S. Senate committee later that month they decided not to do, citing the agency's involvement in the lawsuit.
India Kudankulam nuclear plant 'safe' - APJ Abdul Kalam -BBC, Nov. 6
- Speaking on a visit to the Kudankulam plant, he said it was equipped with "sophisticated safety features and there is no need to panic".
- Work at the plant has been halted following protests by local villagers.
- "We need to know about the waste issues, the overall fresh-water issues. There are so many other issues that have been left unanswered until now," SP Udhayakumar of People's Movement against Nuclear Energy said.
TEPCO begins removing cesium from spent fuel pool -NHK, Nov. 6
- Tokyo Electric Power Company installed a device to remove cesium inside the cooling water of the spent fuel pool at the No.2 reactor. The device became operational on Sunday.
- The concentration of radioactive cesium remains high in the cooling water of the spent fuel pools following meltdowns at the No. 1, 2, and 3 reactors.
- TEPCO has been removing radioactive material from the reactors' cooling water since July, but the No.2 reactor became the first where the procedure took place in the spent fuel pool.
- There are fears that the metal pipes and walls of the spent fuel pools will erode, as seawater was used after the accident to cool down the spent fuel pools of the No. 2, 3 and 4 reactors. TEPCO has already begun removing salt from the water in the pool at the No.4 reactor, and plans to do the same at the pool of the No.2 reactor.
TEPCO to review criteria for determining 'criticality' -Mainichi News, Nov. 7
- Tokyo Electric Power Co. said Sunday it will review its criteria for determining a self-sustaining nuclear chain reaction, known as criticality, in the wake of recent confusion over a case of "spontaneous" fission, which occurs at a constant rate.
Smaller increase in children's weight in Fukushima -NHK, Nov. 7
- A survey shows that some children in Fukushima Prefecture have smaller average weight gains this year compared to the year before. A pediatrician says the results indicate the negative effects of the nuclear plant accident in March.
- Doctor Shintaro Kikuchi tracked the weights of 245 children aged from 4 to 6 in 2 kindergartens in Koriyama City, Fukushima Prefecture. The results show an average weight increase of 0.81 kilograms over the past year through June. The increase for children in the same age group the previous year was 3.1 kilograms.
Low radiation areas should be used as bases for restoration work for Fukushima: expert -Mainichi News, Nov. 7
- Areas that are contaminated with relatively low radiation from the Fukushima No. 1 Nuclear Power Plant should be used as bases for prolonged work to restore the disaster-hit prefecture, a leading radiation expert says.
- "Work to decontaminate and improve infrastructure (in Fukushima) should be carried out first in low radiation areas as bases," said Tatsuhiko Kodama, head of the Radioisotope Center at the University of Tokyo. After obtaining permission from local municipalities in the evacuation zone within 20 kilometers from the crippled Fukushima nuclear power station, Kodama, accompanied by journalists, measured radiation levels of areas in the region on Nov. 5. There were areas that measured less than 1 millisievert per year (0.23 microsieverts per hour) – the lowest level of radiation which requires the central government to conduct decontamination work.
Nuclear power companies subject to cyber attacks -NHK, Nov. 7
- NHK asked 10 electric power companies that manage nuclear power plants if they have experienced attacks on their computer networks in the past year.
- Tokyo Electric Power Company, Hokkaido Electric Power Company and Tohoku Electric Power Company said they had received targeted cyber attacks through emails disguised as business communications from government offices.
- TEPCO says, however, that it has no evidence of an information leak.
- Five other utilities reported that their computers were hit by viruses delivered through email, but they also said they have had no data leakage.
Robot suits tested for Fukushima nuclear plant -NHK, Nov. 7
- The device has sensors that move the brace based on nerve signals from the human brain.
- The venture has now reinforced the robot suit's materials to strengthen its lifting power so that it can be used at the Fukushima nuclear plant.
- University of Tsukuba Professor Yoshiyuki Sankai says the robot suits will enable workers to do many more types of work and stay longer inside the reactor buildings. He says it may be possible to put the nuclear plant under control earlier if the device is used.
Plutonium's unusual interactions with clay may minimize leakage of nuclear waste -Nuclear Power Daily, Nov. 7
- As a first line of defense, steel barrels buried deep underground are designed to keep dangerous plutonium waste from seeping into the soil and surrounding bedrock, and, eventually, contaminating the groundwater. But after several thousand years, those barrels will naturally begin to disintegrate due to corrosion. A team of scientists at Argonne National Lab (ANL) in Argonne, Ill., has determined what may happen to this toxic waste once its container disappears.
- Plutonium, with its half-life of 24 thousand years, is notoriously difficult to work with, and the result is that very little is known about the element's chemistry. Few labs around the world are equipped to handle its high radioactivity and toxicity, and its extremely complicated behavior around water makes modeling plutonium systems a formidable task.
- Plutonium's extraordinary chemistry in water also means scientists cannot directly equate it with similar elements to tell them how plutonium will behave in the environment. Other ions tend to stick to the surface of clay as individual atoms. Plutonium, on the other hand, bunches into nanometer-sized clusters in water, and almost nothing is known about how these clusters interact with clay surfaces.
- "This is a field that is only just emerging," Schmidt says.
Japan study factors accident risk into nuclear power cost estimates -Reuters, Nov. 8
- The cost of generating nuclear power in Japan would rise by up to 1.6 yen per kilowatt hour if the risk of a serious nuclear accident like the one in Fukushima is factored in, a government panel of experts estimated, providing a key element for the government to decide on its post-Fukushima energy policy.
- Lawmakers and officials are working to come up with a new energy policy after the Fukushima radiation crisis made it difficult, if not impossible, to build more reactors in the world's third-biggest generator of nuclear power.
- In 2004, a government panel's assessment of the cost of hydro, fossil fuel and nuclear power generation had concluded atomic power at 5 to 6 yen per kwh would be the cheapest energy option most of the time. The assessment reflected the 40-year operation cost of a model reactor but did not factor in the risk of a serious accident or the cost for recycling waste nuclear fuel.
Fukushima health concerns -Japan Times Editorial, Nov. 8
- It is of great concern that little has been disclosed regarding the conditions of the workers at the Fukushima No. 1 nuclear power plant. Tepco and the central government should disseminate information on the actual working conditions of these people, even if such information seems repetitious and includes what they regard as minor incidents. People are forgetful. They need to be informed. Such information will help raise people's awareness about the issue of radiation and its impact on health.
- It must not be forgotten that exposure to radiation has long-term effects on human health. In the Hiroshima and Nagasaki atomic bombings, the number of leukemia cases started to increase among bombing survivors two years after the bombs were dropped. In the case of the 1986 Chernobyl accident, thyroid cancer began to appear among children several years after the disaster happened. Particular attention should be paid to the health of children.
Tokyo city starts radiation tests on food in shops -Terra Daily, Nov. 8
- It is rare that authorities check on products at the point of sale and the the inspection includes processed food as well as fresh produce.
- The metropolitan government is measuring radiation on vegetables and other fresh food to complement pre-shipment tests at places of production.
- "We are conducting tests on the food residents are actually buying at supermarkets and other retail stores," an official in charge of the food monitoring said, adding some Tokyo residents had requested the tests.
- The city plans to conduct tests on 20-30 items a week, he said.
Japan Invents a Cyborg Suit to Clean Up Fukushima -Atlantic Wire, Nov. 8
- We'll be the first to say it: HAL looks awesome. Described both as a "wearable robot" and "the world's first cyborg-type robot," the model pictured to right gives you a rough idea of the suits main features. The Control Unit more or less serves as the machine's brain, while the various battery-fueled Power Units are the engines. The Bio-Electric Signal Sensors actually attach to the wearer's skin to pick up on "faint biosignals" that pulse through our skin and enable HAL to predict the wearer's next move. We're not sure how well it works, but if you painted it blue and strapped a cannon on the right arm, it would look just like Mega Man. See the comparison?
Seventeen workers exposed to radiation at Idaho lab -Reuters, Nov. 8
- Seventeen workers were exposed to low-level radiation from plutonium on Tuesday at a U.S. Energy Department nuclear research lab in Idaho, but there was no risk to the public, the government said.
- The accident at the Idaho National Laboratory occurred inside a facility used for remotely handling, processing and examining spent nuclear fuel, radioactive waste and other irradiated materials, the lab said in a series of statements.
- The so-called Materials and Fuels Complex is located near the edge of the sprawling 890-square-mile laboratory site in the high desert in eastern Idaho about 38 miles from the city of Idaho Falls.
Radiation cleanup plan falls short -Japan Times, Nov. 9
- 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.
- The experts said the government's goal of human effort achieving a 10 to 20 percent reduction is not ambitious enough.
- Tanaka meanwhile pointed out that the government has not even floated a plan for decontaminating the no-go zones where the radiation exceeds 20 millisieverts per year areas where there isn't even a timetable for when evacuees will be able to return.
Residents sue over Tsuruga reactors -Japan Times, Nov. 9
- A group of about 40 people sued Japan Atomic Power Co. on Tuesday seeking a provisional court order not to restart two reactors at its Tsuruga nuclear power plant on the Sea of Japan in Fukui Prefecture.
- In the suit filed with the Otsu District Court, the plaintiffs argue that Lake Biwa, Japan's biggest lake and source of water for the Kansai region centering on Osaka, could be contaminated and residents could be endangered if a nuclear accident occurs at the plant.
- Currently the plant's two reactors, one with output capacity of 357,000 kw and the other with capacity of 1.16 million kw, are shut down for regular checkups.-
- The plaintiffs, mainly residents of Shiga Prefecture just south of Fukui Prefecture, insist that the Tsuruga plant was built on a site with a fault below it, leaving it susceptible to a severe accident.
1 in 4 residents of towns around Fukushima plant don't want to return -Kyodo, Nov. 9
Govt to bring view on low-level radiation impact -NHK, Nov. 10
- The government held its first meeting of a 9-member expert team to study the radiation impact on Wednesday evening, attended by Goshi Hosono, the minister in charge of the nuclear crisis.
- The panelists agreed to formulate a view as early as the beginning of December on the impact on human health of radiation levels of 20 millisieverts per year. That's the exposure limit used by the Japanese government to specify the evacuation zone around the stricken Fukushima Daiichi nuclear plant.
- The panelists also agreed to hear opinions from experts who are critical of the government's policies, as well as from specialists overseas.
Is Post-Fukushima Japan Safe for Tourists? -TIME, Nov. 10
- The government hasn't helped make the case that Japan is indeed safe to visit again. In October there was an outcry in the media after residents in and around Tokyo conducted their own independent radiation tests and found several areas of contamination. This flew in the face of repeated assurances from the government that radiation from Fukushima had not spread 150 miles (240 km) south to the capital and didn't pose a risk to residents. A comprehensive decontamination program will finally be implemented in northeastern Japan when a new cleanup law takes effect on Jan. 1. Still, it could take years to collect and store the tons of contaminated soil in the region.
- Equally worrisome is food safety. Japan has yet to establish a centralized system for detecting radiation in food products, leaving the job to local authorities and the farmers themselves. Foods like spinach, mushrooms, tea, bamboo shoots, milk and plums as far as 220 miles (350 km) from Fukushima have been contaminated with iodine and radioactive cesium, which can damage cells and lead to an increased risk of cancer. Seafood is also a major concern. In July, the waters near the Fukushima reactors were found to contain 30 times the allowable safety level of cesium-134. On Monday, however, a government official tried to prove that water collected from the basement of the crippled reactors was now safe by drinking a glass of it live on Japanese television.
- Many hotels and tour companies are now offering special deals to try to drum up business. One ski company, SkiJapan.com, says it's giving away free nights at hotels to attract customers this winter. Traditional inns are also running promotions. The Kashiwaya Ryokan in Gunma prefecture northwest of Tokyo is offering rooms at half price to foreigners on the condition they post impressions of their stay on TripAdvisor and Facebook. And the Japan Tourism Agency announced in October a proposal to offer free round-trip airfare to 10,000 foreign residents next year, pending budgetary approval.
What's the Fallout for Dogs Near Fukushima? -PBS, Nov. 10
- At the tail end of Miles O'Brien's latest NewsHour report on radiation in Japan, a golden dog with a thick red collar trots into the street of the abandoned town, Katsurao, and weaves along the center divider.
- Miles asks, off camera: "Do we have anything to feed him?"
- The piece, which airs tonight, reports on the group Safecast, which has measured, mapped and crowdsourced data on radiation levels in locations throughout Japan, particularly in the hot spots near the Fukushima Daiichi nuclear plant.
- The dog was one of several scrawny, undernourished dogs and cats they encountered, most likely abandoned by their owners during rapid evacuation. (The crew did, incidentally, have food in their supply for the dog - sweet buns with bean paste and sushi.)
- "These were not feral cats and dogs," Jardin said. "It's obvious they were part of someone's family. As you feel empathy for these abandoned creatures, you start to feel the scope of the disruption and abandonment and complete destruction of the social fabric in Japan. The Japanese are very, very sweet to their pets."
- As long as the animals are appropriately cleaned and quarantined, they should be ultimately safe to handle and adopt, said Timothy Mousseau, a professor of biological sciences at the University of South Carolina, who has extensively studied animals – mostly birds and insects – exposed to radiation.
- Mousseau's research has found significant genetic damage and breakages in chromosomes among animals exposed to radiation in and around Chernobyl. Developmental abnormalities, tumors, and species decline and extinction have also been attributed to radiation exposure in the area.
TEPCO: hydrogen from reactor caused blast -NHK, Nov. 10
- The operator of the Fukushima Daiichi nuclear plant says the explosion of the facility's Number 4 reactor on March 15th was caused by a backflow of hydrogen from an adjacent building.
- The blast was initially thought to have been caused by hydrogen created when spent fuel stored in a pool at the reactor building was damaged by the devastating March 11th quake.
- TEPCO workers who entered the building on Tuesday to determine the cause found that the 5th floor was more severely damaged than the 4th, where a pool of spent fuel is located, and that the fuel was intact.
- The workers also confirmed that an air conditioning duct on the floor was severely damaged.
- TEPCO says the hydrogen likely flowed into the reactor through the duct connected to the plant's Number 3 reactor when workers released pressurized air from it to prevent a hydrogen blast.
- The firm says the explosion very likely occurred after the density of hydrogen in the duct increased.
- A hydrogen blast took place at the Number 3 building a day before the explosion at the Number 4 building.
Tepco told to revise Fukushima road map -Japan Times, Nov. 10
- The government on Wednesday ordered Tokyo Electric Power Co. to create by the end of the year a new schedule for scrapping the crippled nuclear reactors at the crisis-hit Fukushima No. 1 power complex, as the plant nears a cold shutdown.
- It also ordered the utility to start removing the plant's spent nuclear fuel within two years a year earlier than the initial plan so that workers can focus on tackling the more difficult task of extracting melted fuel from the reactors as early as possible, nuclear disaster minister Goshi Hosono said.
- Although the work is expected to place an additional financial burden on the beleaguered company, Hosono and industry minister Yukio Edano both stressed the government would make sure the company's financial condition does not delay progress toward scrapping the plant, although they did not elaborate.
MHI N-plant data compromised / Infected server leaked plant designs during recent cyber-attacks -Yomiuri, Nov. 10
- Sensitive design and other information on nuclear power plants was leaked during cyber-attacks that targeted major defense contractor Mitsubishi Heavy Industries Ltd., it has been learned.
- According to informed sources, there are signs that data was transmitted outside the company's computer network from two servers infected by a virus during the attacks. Data from noninfected servers that had been covertly shifted to the infected computers also might have been leaked, the sources said.
- Most of the leaked information involved design plans for nuclear plants and other equipment, leading some observers to believe the attacks were targeting civilian intellectual property.
- The Economy, Trade and Industry Ministry is trying to pinpoint the source of and motive for the attacks that infected 83 servers and computers at MHI.
Fukushima: They Knew -Greg Palast for Free Press, Nov. 10
- I've seen a lot of sick stuff in my career, but this was sick on a new level.
- Here was the handwritten log kept by a senior engineer at the nuclear power plant:
- Wiesel was very upset. He seemed very nervous. Very agitated. . . . In fact, the plant was riddled with problems that, no way on earth, could stand an earth- quake. The team of engineers sent in to inspect found that most of these components could "completely and utterly fail" during an earthquake.
- "Utterly fail during an earthquake." And here in Japan was the quake and here is the utter failure.
Hacking geigers: Safecast crowdsources radiation data in Japan after Fukushima disaster -BoingBoing, Nov. 10
- On PBS NewsHour tonight, a report I helped the program's science correspondent Miles O'Brien produce about the challenge people in Japan face of finding and sharing reliable data about radiation contamination, after the disaster at the Fukushima Daiichi nuclear plant.
- Embedded above, a conversation between Miles and NewsHour host Hari Sreenivasan about our report, which focuses on a grassroots group called Safecast that measures, maps, and publishes data on radiation contamination levels throughout the country.
Workers Exposed to Plutonium Oxide During Decommissioning of Idaho Nuclear Reactor -FOXNEWS, Nov. 10
- Initial body scans on 16 employees potentially exposed to radioactive materials were completed Tuesday night, Idaho National Laboratory (INL) announced, with further follow-up lung scans conducted Wednesday on three workers.
- At least two of those workers inhaled plutonium oxide at the Zero Power Physics Reactor, a facility located 38 miles from Idaho Falls that has been closed down since 1992, the Idaho Statesman reported.
- The workers were packaging the material for transport to a Department of Energy facility in Nevada.
- Plutonium oxide exposure externally is not a threat, the Statesman reported, but once in the bloodstream it can reach body organs where it can lodge for decades and continue to expose surrounding tissue to radiation and increase the risk of cancer.
Gov't to reduce radiation dose for children by 60% in 2 yrs -Kyodo, Nov. 11
An American Look at Fukushima, Minute by Minute -NYT, Nov. 11
- One lesson involves the nature of radiation protection for plant workers in an emergency. Two operators received more than 60 rem (0.6 Sv), far above the level at which changes in blood chemistry can be observed and almost at the level where symptoms like nausea and vomiting begin.
- But most of the dose came not from walking around in places where radiation was present it was internal, meaning it was from particles inhaled or swallowed by the workers. Radioactive material that is lodged in the body will deliver a dose for an extended period.
- Radiation doses were high by American standards. The Japanese government set an emergency limit of 10 rem (0.1 Sv). By comparison, nearly all American plant workers get less than two rem (0.02 Sv) a year, and the upper limit in this country is five rem (0.05 Sv).
- But by the end of March, approximately 100 workers had received doses greater than 10 rem, the chronology said.
A Visit to Fukushima Begins -NYT, Nov. 11
- Eight months after the Fukushima Daiichi nuclear power station was crippled by an earthquake and tsunami, the Japanese government is opening the compound and surrounding area to the media for the first time. On Friday, officials took a group of reporters, including Martin Fackler of The New York Times, on a tour of J-Village, a former sports center near the plant that is now being used to house workers laboring to bring the plants reactors under control. On Saturday, the reporters will tour the plant itself.
A Tour of Fukushima's Worker Village -Atlantic Wire, Nov. 11
- For the first month in the eight months since an earthquake and tsunami hit the Fukushima nuclear power station, the Japanese government has opened the once very contaminated area to media. To showcase its progress, the government only let four foreign media outlets inside, including Martin Fackler for The New York Times, who details his observations for their Lede blog. Today, journalists were taken through J-Village, the sports complex next to the plant, which has been converted into a contamination area. Tomorrow, they will go into the actual plant. Here are some of Fackler's observations paired with photos by the AP's David Guttenfelder, who was the tour's pool photographer.
Report Gives New Details of Chaos at Stricken Plant -NYT, Nov. 11
- Fukushima Daiichi Unit 1 was stuck in darkness, and everyone on site feared that the reactor core was damaged. It was the day after a huge earthquake and a towering tsunami devastated the plant, and the workers for Tokyo Electric Power Company knew they were the only hope for halting an unfolding nuclear disaster.
- Another power company tried to help. It rushed a mobile electrical generator to the site to power the crucial water pumps that cool the reactor. But connecting it required pulling a thick electrical cable across about 650 feet of ground strewn with debris from the tsunami and made more treacherous by open holes left when manhole covers were washed away.
- The cable, four inches in diameter, weighed approximately one ton, and 40 workers were needed to maneuver it into position. Their urgent efforts were interrupted by aftershocks and alarms about possible new tsunamis.
- By 3:30 in the afternoon, the workers had managed what many consider a heroic feat: they had hooked up the cable. Six minutes later, a hydrogen explosion ripped through the reactor building, showering the area with radioactive debris and damaging the cable, rendering it useless.
Fasano wants Progress to explain botched nuclear plant job -tampabay.com, Nov. 12
- State Sen. Mike Fasano wants Progress Energy to explain to lawmakers and the public what went wrong at the broken Crystal River nuclear plant.
- Fasano, R-New Port Richey, said that with customers potentially on the hook for $670 million in repairs to the plant, the public has a right to understand what caused the utility's nuclear plant to break.
- If the plant can be repaired, it is expected to cost more than $2.5 billion to repair, making it one of the costliest nuclear incidents in U.S. history.
- "I have asked the chairman of the utilities committee to have Progress Energy come before the committee to answer questions, to answer a lot of questions," said Fasano, who is a member of the utilities committee. "I also think it's time for the governor to speak up."
Japan Fukushima Reactor: Eight Months After Nuclear Disaster, Plant Remains In Shambles -HuffPost, Nov. 12
- Two reactor buildings once painted in a cheery sky blue loom over the Fukushima Dai-ichi nuclear power plant. Their roofs are blasted away, their crumbled concrete walls reduced to steel frames.
- In their shadow, plumbers, electricians and truck drivers, sometimes numbering in the thousands, go dutifully about their work, all clad from head to toe in white hazmat suits. Their job cleaning up the worst nuclear disaster since Chernobyl will take decades to complete.
- Reporters, also in radiation suits, visited the ravaged facility Saturday for the first time since Japan's worst tsunami in centuries swamped the plant March 11, causing reactor explosions and meltdowns and turning hundreds of square miles (kilometers) of countryside into a no man's land.
- Eight months later, the plant remains a shambles. Mangled trucks, flipped over by the power of the wave, still clutter its access roads. Rubble remains strewn where it fell. Pools of water cover parts of the once immaculate campus.
Eyewitness report - inside the wreckage of Japan's Fukushima nuclear reactor -Telegraph, Nov. 12
- I was one of around three dozen journalists put onto two buses. We were given protective suits, double gloves, a double layer of clear plastic booties over shoes, hair cover, respirator mask and a radiation detector.
- And then we began our drive to the plant.
- First, we passed through the police check point. Through the bus window, I saw the empty towns of Naraha, Tomioka and Okuma pass by. There were abandoned homes. A plant store with its greenery still on display outside, but withered and dead.
Press tours stricken Fukushima nuclear plant - Washington Post Video, Nov. 12
A Rescue Squad Member Died from Renal Failure 3 Months After He Was Found with Internal Radiation Exposure -EX-SKF, Nov. 12
- A woman in a public forum asked a question to the two panelists: Why did my friend die?
- The event was held in Sapporo City on November 6, 2011.
- Her friend was a member of the special rescue unit of the Fire Department (probably in Osaka) who was sent numerous times to the disaster-affected areas in Fukushima and Iwate for the rescue effort. In July, he was found with internal radiation exposure, but he had to continue working. His employer kept sending him and his colleagues to the disaster area even after the internal radiation exposure was found in them.
- She says that they got sick and they had to quit. But that was after they were berated by their superior as "unpatriotic". Her friend died in 3 months after having been found with internal radiation exposure.
- Good lord.
?Radioactive dust over Sweden - Stockholm News, Nov. 12
- Low concentrations of the isotope Iodine-131 has been detected in the atmosphere ?in several European countries, the Norwegian public broadcaster NRK reports.
- ?We are a little concerned, because there must be a source somewhere, says an official of the IAEA.
Abnormal radioactivity also in Hungary, no risk seen -Space Daily, Nov. 12
- "In Hungary, a higher-than-usual concentration of iodine-131 particles was registered in Budapest and Miskolc (in the northeast)," Geza Safrany, the head of the national research institute for radiology OSSKI, said in a statement.
- He added that the increase was very slight and did not pose any health risk.
- What lay behind this elevated radioactivity is still unclear, he also said.
- On Friday, the UN atomic watchdog in Vienna said it had received information from Czech authorities that "very low levels of iodine-131" had been detected in recent days in the air in the Czech Republic and in other countries.
- Poland, Slovakia and Austria quickly confirmed they too had detected abnormal levels in the last few weeks.
No KANUPP linkage to Radioactivity in Europe, PAEC clarifies -Associated Press of Pakistan, Nov. 13
- The release of Iodine-131 is not possible unless there is a nuclear fuel failure, while the incident at KANUPP involved leakage of heavy water which contains tritium and not Iodine-131, said the official.
- Higher radiation levels were detected in Poland and Ukraine even before October 19 when the KANUPP incident had not even taken place. It may be added that even if there was a leakage from KANUPP, it could not have traveled to Europe without leaving any trace in the surroundings.
Fukushima No. 1 stable: plant chief -Japan Times, Nov. 13
- Making his first public appearance since the nuclear accident at the Fukushima No. 1 power plant in March, the facility's general manager, Masao Yoshida, apologized for failing to prevent the triple meltdowns but emphasized that conditions at the plant have "definitely been stabilized."
- Yoshida met reporters at the wrecked power station as Tokyo Electric Power Co., the plant's operator, allowed reporters to visit the facility for the first time since the March 11 earthquake and tsunami triggered the nuclear crisis.
- "The first thing I would like to do is to apologize to the people of Fukushima and in the whole of Japan for causing them great trouble," Yoshida said.
- Yoshida has led the workers trying to contain the Fukushima No. 1 plant's stricken reactors since the first day of the nuclear crisis. He confessed that he almost gave up on several occasions, and in the first days of the disaster he even feared he could die from excessive radiation exposure.
- "Several times during the first week of the crisis, I thought I would soon die," Yoshida said.
TEPCO says conditions for nuclear plant workers improving -Japan Today, Nov. 13
- Work inside the facility, which a government panel this month announced will likely take 30 years or more to safely decommissioned, continues to be extremely risky.
- But officials with the Tokyo Electric Power Co (TEPCO) say the plant has now stabilized enough to allow up to 3,300 workers onto the facility each day. Over the past several months, they have restored its cooling systems to keep the reactors at a fairly low and constant temperature, repaired damaged buildings and machinery and conducted decontamination tasks.
- We are doing all we can to bring this crisis to an end, said TEPCO spokesman Yoshimi Hitosugi. He said TEPCO had determined that the situation at the plant had improved enough for it to open the J-Village staging area on Friday and allow representatives of the Japanese and international media into the plant itself on Saturday.
Antinuclear-plant protesters rally in Fukuoka -Japan Times, Nov. 14
- A series of large antinuclear rallies took place in Fukuoka on Sunday with the organizer saying more than 15,000 people, including from South Korea, took part calling for dismantlement of all nuclear power plants in Japan.
- Yukinobu Aoyagi, a leading member of the events, told a gathering in a park in the southwestern city, "We'll work together so as not to see our soil contaminated with radiation."
Taking thyroid tests to the children in Fukushima -NHK, Nov. 14
- Medical personnel visited a health center and a nursery school in Kawamata Town on Monday and conducted ultrasound scans on about 240 children. The town is about 47 kilometers from the Fukushima Daiichi nuclear plant.
- The tests, which began last month, were initially available only at a medical university in Fukushima City.
- The results of the tests will be mailed out in about a month.
- The Fukushima children will undergo thyroid checks every two years until they turn 20, and once every five years after that.
Power plant chief details Fukushima nuclear disaster -Mainichi News, Nov. 14
- Question: This is the first time that you are speaking in front of the press corps. First of all, what do you want to say to the Japanese public?
- Answer: I want to apologize from the bottom of my heart for the trouble and inconvenience that the power plant I am in charge of caused. We have received letters of support from all over Japan and around the world, and it's a great encouragement in particular to receive assuring words from the people of Fukushima Prefecture.
- Q. What was the toughest situation you found yourself in throughout the crisis?
- A. Naturally, it was the first week from March 11. I had no idea what was going to happen next, and we did everything imaginable. To put it in an extremely frank manner, we thought several times that we were going to die.
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I have a cousin who was a chemistry professor and did a follow-up study on Three Mile Island. His conclusion was that nuclear energy production can be safe but that you can't trust the private companies to do this. All the news we're hearing seems to confirm the second part of his conclusion.
Same was true of the Three Mile Island aftermath. That was another seat-of-the-pants operation.
I would trust private corporation as long as the executives and board members lived within 300 meters of the plant and at least half of them had to be there at all times for the plant to be operating.
No, wait, that probably wouldn't work...
The xenon in reactor #2 was detected because the Fukushima workers managed to connect up a line to sample and analyze that reactor's atmosphere. The levels were extremely low, and eventually attributed to spontaneous fission of californium - one of the heavy-element actinides generated by neutron absobtion during reactor operation.
This concept was proved out by adding boron to the injected water, to soak up neutrons. The xenon rate stayed unchanged.
"Critical" means that the neutrons from each neutron-caused fission cause an average of one more fission. Spontaneous fission is (of course) not neutron-caused.
"Critical mass" doesn't really apply to power stations. It's more like "critical configuration", with fuel rods and moderator (water) both needing to be present in a suitable layout. Then you can get neutrons of the right speed without having too many absorbed elsewhere.
Joffan, yes, that is more or less what we report in the feed.
I don't fully buy it, as had it been expected it would not have been surprising, and frankly, I don't trust those on the scene any more. No reason I should.
Update on the I-131 in Europe.
Hungary isotope lab likely radioactive source: IAEA
The Hungarian institute, which produces radioisotopes for healthcare, research and industry, said earlier on Thursday that it had suspended production.
Greg, right, I see that you have some mention of the spontaneous fission explanation. Californium is correct, curium (NHK) was a mistranslation or misinterpretation somewhere along the line.
Actually I'm going to backtrack on my preivous post. Curium probably is correct and it was my misinterpretation.
@Joffan: Thanks for the update on the I-131 in Europe. I'll just note that the report you link to includes "DOUBT".
Ana, np, I'll just note that the DOUBT is from the director of the institute concerned...