The facility handled plutonium but was unaware that a major accident could happen.
As the facts surrounding the June 6 incident where five workers were exposed to radioactive materials following an accident at a nuclear research facility in Ibaraki Prefecture continue to emerge, it has become clear that the facility’s stance concerning safety management has been simply too soft — especially considering that it handles materials used for nuclear fuel.
The accident in question happened at around 11:15 a.m. on June 6 at the Japan Atomic Energy Agency (JAEA)’s Oarai Research & Development Center in the coastal town of Oarai in Ibaraki Prefecture. Uranium oxide and plutonium oxide powder that had been stored in double-wrapped plastic bags inside a sealed stainless steel container were accidentally released across the research laboratory after the bags suddenly burst, thereby exposing all five workers nearby to the radioactive compounds. Prior to the leak, one of the workers — a man in his 50s — was opening the container for inspection.
The check was carried out at an unsealed work station referred to as the “hood.” The radioactive materials had been stored at a pressure level lower than the surrounding area, in an attempt to prevent them from leaking. However, this proved to be ineffective. The compounds flew across the room, in powder form, immediately after the bags burst open.
In addition to the hood, there is also a “glove box” inside the facility, which can be used to handle dangerous materials. However, the facility has no specific rules determining which work station should be used for which purpose, and it has become normal practice at the site for workers to handle sealed nuclear materials — such as those kept inside containers — at the hood work station.
Apparently, during the check of the stainless steel container at the Oarai facility, there was no intention of opening the plastic bags, and therefore, it was judged that, “There was no danger of being exposed to radiation.”
However, the contents of the stainless steel container had not been checked once in 26 years. Commenting on this issue, an executive from the Nuclear Regulation Authority (NRA) has criticized the JAEA, stating, “How could they even be sure that the contents were kept sealed?” Meanwhile, an executive from the JAEA has said, “It was not anticipated that the plastic bags would burst. It seems that working at the hood work station may have been inappropriate.”
In addition, it has become clear that the five workers were not wearing full-face masks at the time of the accident. Instead, they were wearing masks that only covered their noses and mouths. Also, despite the fact there was a surveillance camera in the room, no footage was recorded, and no one was video monitoring the situation at the time of the accident.
Furthermore, an official from the NRA points out that, “It seems the facility was unaware that a major accident could happen.”
https://mainichi.jp/english/articles/20170613/p2a/00m/0na/016000c
June 13, 2017
Posted by dunrenard |
Japan | Oarai Research & Development, plutonium |
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In January 2017, the Chiba Prefectural Board of Education was notified that radiation above the national standard level was measured at the Kashiwa city central gymnasium.
Following that report the Chiba Prefectural Board of Education conducted an investigation in Kashiwa city from late April to the middle of May 2017.
A radiation level exceeding the national standard of 0.23 microsievert per hour was detected on the premises of five schools in Kashiwa City, The radiation measured at 1 meter above ground level ranged from 0.24 to 0.72 microsievert.
At Kashiwa High School, Higashi Tsukuba High School and Middle School, Kashiwa Chuo High School, Kashiwanami High School and Kusanami Takayanagi High School, at places where usually no one enters: near a pool, at the back of a bicycle parking lot, etc..
The prefectural Board of Education decided to cordon those hot spots, to prohibit the entry and to decontaminate those places by soil removal.
They are also planning to conduct a radiation levels survey to the schools outside of Kashiwa city.
http://www3.nhk.or.jp/news/html/20170612/k10011015111000.html
Kashiwa city, 47.1km from Tokyo
June 12, 2017
Posted by dunrenard |
Japan | Chiba Prefecture, Fukushima Radiation, Hotspots, Kashiwa City |
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Increase in Cancer Risk for Japanese Workers Accidentally Exposed to Plutonium http://allthingsnuclear.org/elyman/cancer-risk-for-japanese-exposed-to-plutonium#.WTxxNdgMNK8.twitter, ED LYMAN, SENIOR SCIENTIST | JUNE 9, 2017,
We wish to express our sympathy for the victims of this accident.
This incident is a reminder of the extremely hazardous nature of these materials, especially when they are inhaled, and illustrates why they require such stringent procedures when they are stored and processed.
According to the earliest reports, it was estimated that one worker had inhaled 22,000 becquerels (Bq) of plutonium-239, and 220 Bq of americium-241. (One becquerel of a radioactive substance undergoes one radioactive decay per second.) The others inhaled between 2,200 and 14,000 Bq of plutonium-239 and quantities of americium-241 similar to that of the first worker.
More recent reports have stated that the amount of plutonium inhaled by the most highly exposed worker is now estimated to be 360,000 Bq, and that the 22,000 Bq measurement in the lungs was made 10 hours after the event occurred. Apparently, the plutonium that remains in the body decreases rapidly during the first hours after exposure, as a fraction of the quantity initially inhaled is expelled through respiration. But there are large uncertainties.
The mass equivalent of 360,000 Bq of Pu-239 is about 150 micrograms. It is commonly heard that plutonium is so radiotoxic that inhaling only one microgram will cause cancer with essentially one hundred percent certainty. This is not far off the mark for certain isotopes of plutonium, like Pu-238, but Pu-239 decays more slowly, so it is less toxic per gram. The actual level of harm also depends on a number of other factors. Estimating the health impacts of these exposures in the absence of more information is tricky, because those impacts depend on the exact composition of the radioactive materials, their chemical forms, and the sizes of the particles that were inhaled. Smaller particles become more deeply lodged in the lungs and are harder to clear by coughing. And more soluble compounds will dissolve more readily in the bloodstream and be transported from the lungs to other organs, resulting in exposure of more of the body to radiation. However, it is possible to make a rough estimate.
Using Department of Energy data, the inhalation of 360,000 Bq of Pu-239 would result in a whole-body radiation dose to an average adult over a 50-year period between 580 rem and nearly 4300 rem, depending on the solubility of the compounds inhaled. The material was most likely an oxide, which is relatively insoluble, corresponding to the lower bound of the estimate. But without further information on the material form, the best estimate would be around 1800 rem.
What is the health impact of such a dose? For isotopes such as plutonium-239 or americium-241, which emit relatively large, heavy charged particles known as alpha particles, there is a high likelihood that a dose of around 1000 rem will cause a fatal cancer. This is well below the radiation dose that the most highly exposed worker will receive over a 50-year period. This shows how costly a mistake can be when working with plutonium.
The workers are receiving chelation therapy to try to remove some plutonium from their bloodstream. However, the effectiveness of this therapy is limited at best, especially for insoluble forms, like oxides, that tend to be retained in the lungs.
The workers were exposed when they opened up an old storage can that held materials related to production of fuel from fast reactors. The plutonium facilities at Tokai-mura have been used to produce plutonium-uranium mixed-oxide (MOX) fuel for experimental test reactors, including the Joyo fast reactor, as well as the now-shutdown Monju fast reactor. Americium-241 was present as the result of the decay of the isotope plutonium-241.
I had the opportunity to tour some of these facilities about twenty years ago. MOX fuel fabrication at these facilities was primarily done in gloveboxes through manual means, and we were able to stand next to gloveboxes containing MOX pellets. The gloveboxes represented the only barrier between us and the plutonium they contained. In light of the incident this week, that is a sobering memory.
June 12, 2017
Posted by Christina Macpherson |
- plutonium, health, Japan, radiation, Reference |
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Takahama’s problematic restart http://www.japantimes.co.jp/opinion/2016/02/10/editorials/takahamas-problematic-restart/#.WTy9t5KGPGh, FEB 10, 2016 The No. 3 reactor of Kansai Electric Power Co.’s Takahama nuclear power plant in Fukui Prefecture, which was restarted in late January, is expected to start commercial operations in late February. Its No. 4 reactor is also set to be restarted around the same time. Although the Takahama Municipal Government and Fukui Prefecture gave their consent to the restart, there are serious concerns, including those expressed by nearby municipalities and their residents.
Following the restart of the No. 1 and No. 2 reactors at Kyushu Electric Power Co.’s Sendai nuclear power plant in Kagoshima Prefecture, Takahama unit 3 is the third reactor to come back online under the safety regulations introduced by the Nuclear Regulation Authority following the shutdown of the nation’s nuclear plants in the wake of the March 2011 disaster at Tokyo Electric Power Co.’s Fukushima No. 1 plant. But it is the first to run on mixed oxide (MOX) fuel, which contains not only uranium but also plutonium extracted from spent nuclear fuel. The No. 4 reactor at Takahama will also use MOX fuel.
Japan has accumulated 48 tons of plutonium — enough to make an estimated 6,000 nuclear bombs — as a result of the government’s nuclear fuel cycle policy, which aims to reprocess spent fuel to extract uranium and plutonium to be used again as fuel. The Takahama restart may help the government show its resolve to cut its plutonium stockpile to address U.S. concerns over nuclear proliferation. But the restart will pose a problem in the not-too-distant future. The spent fuel storage facilities for reactors 3 and 4 are expected to become filled in seven or eight years after they are reactivated. Spent uranium fuel from nuclear power plants is to be sent to a fuel reprocessing facility in Rokkasho, Aomori Prefecture, still on a trial run, but the plant cannot reprocess used MOX fuel — meaning that there will be no place to store overflowing spent fuel from the Takahama reactors. Although Kansai Electric aims to choose a site for a medium-term storage facility outside Fukui by around 2020, no prefectures seem willing to host it.
In the wake of the 2011 Fukushima disaster, local governments within 30 km of a nuclear power plant are now required to devise plans to evacuate their residents in the event of a major accident. In the case of Takahama, nearly 180,000 residents in 12 municipalities in Fukui, Kyoto and Shiga prefectures live in the 30-km zone. Part of the city of Maizuru, Kyoto Prefecture, is within 5 km of the Takahama plant. Despite this, Kansai Electric stuck to the position that to restart the reactors it only needs consent from the host town of Takahama and Fukui Prefecture, and it ignored calls from Kyoto and Shiga prefectures and many other municipalities within the 30-km zone that it should also gain their consent. The same situation happened when Kyushu Electric Power Co. pushed to restart the Sendai reactors. The power companies should address the concerns harbored by municipalities and residents that do not host plants but lie close enough to be affected by a nuclear disaster.
Despite the requirement for compiling evacuation plans, no evacuation drills with local residents have been carried out in the municipalities around Takahama and many residents have received no instructions on where they should evacuate to in the event of a severe accident. Maizuru, for example, won’t release a new evacuation plan for its residents until March. While there are plans to evacuate some Fukui residents to Hyogo, Kyoto and Tokushima prefectures, many municipalities are not ready to receive them. In addition, evacuations may not proceed as planned in extreme weather conditions such as heavy snow or when roads are congested. The Fukushima disaster also exposed the evacuation difficulties faced by inpatients at hospitals and elderly people in nursing care facilities. And as there are few access roads to the Takahama facility, the evacuation of plant workers and dispatch of emergency teams may be hindered. The Takahama facility is among 14 nuclear power plants concentrated by Wakasa Bay in Fukui Prefecture. If a major disaster hits the plants simultaneously, the area will be highly vulnerable.
In December, the Fukui District Court quashed an injunction issued by the same court in April against restarting the Takahama reactors, paving the way for Kansai Electric to put them back online. Although the ruling upheld the NRA’s new safety standards for restarting reactors as rational and endorsed the authority’s decision that the Takahama reactors met the standards, both Kansai Electric and the NRA should not forget that the ruling also stated that the NRA’s decision does not rule out the possibility of a severe accident and that high-level efforts for safety must be constantly maintained because there is no such thing as absolute safety. Since it is believed that controlling a reactor that burns MOX fuel is more difficult than one that uses uranium, Kansai Electric cannot be too cautious in operating the Takahama plant.
June 12, 2017
Posted by Christina Macpherson |
Japan, safety |
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Hitachi scrambles to divest UK nuclear risks after Toshiba fiasco.
Nikkei Asian Review 9th June 2017 Hitachi will curtail its financial risk in the construction of two nuclear power plants in the U.K. by divesting itself of the local subsidiary that will build and operate them, the Japanese conglomerate announced Thursday.
The news came at an event held here to draw partners to invest in Horizon Nuclear Power, which Hitachi acquired in 2012 as a wholly owned subsidiary. If Hitachi fails to do so before construction starts in 2019, forcing it to bear practically all the financial risk of the project, it will suspend its plans for the 2 trillion yen ($18.1 billion) project.
Hitachi is proceeding cautiously with its own nuclear energy business studying Toshiba’s troubles in the U.S. with Westinghouse Electric. Hitachi now is appealing to energy companies and others to invest in Horizon so it can turn the company into an unconsolidated subsidiary and is prepared to reduce its stake to as low as zero. Operation of the power plants would be entrusted to Horizon. http://asia.nikkei.com/Business/Companies/Hitachi-scrambles-to-divest-UK-nuclear-risks-after-Toshiba-fiasco
June 12, 2017
Posted by Christina Macpherson |
business and costs, Japan, UK |
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The operator of a nuclear research facility north of Tokyo has detected contaminants scattered in the same room in which workers were exposed to radioactive substances from a nuclear fuel container.
Five workers were inspecting the container at the facility in Ibaraki Prefecture on Tuesday. A bag inside the canister suddenly burst, expelling radioactive powder.
The operator, Japan Atomic Energy Agency, says it has detected radioactive substances from 14 sections of the room’s floor. It says measurements reached a maximum of 55 becquerels per square centimeter.
Photos taken a day after the accident show black flecks scattered on the floor. The agency says they could be plutonium and uranium.
After the accident, the 5 workers were kept in the contaminated room for 3 hours. Agency officials said they did not anticipate an incident of this kind, and needed time to set up a tent outside the room to decontaminate the workers.
The agency earlier said one of the workers had 22,000 becquerels of radioactive substances in his lungs. This level of exposure can cause major damage to health. But it now says the actual figure could be lower. Officials say the testing device may have also measured contaminants on the surface of the man’s body.
The worker has been transferred to the National Institute of Radiological Sciences. The officials say plutonium was not detected in an initial test there.
https://www3.nhk.or.jp/nhkworld/en/news/20170610_04/
June 11, 2017
Posted by dunrenard |
Japan | Exposure, Oarai Research & Development, plutonium, Workers |
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According to news reports, five workers were accidentally exposed to high levels of radiation at the Oarai nuclear research and development center in Tokai-mura, Japan on June 6th. The Japan Atomic Energy Agency, the operator of the facility, reported that five workers inhaled plutonium and americium that was released from a storage container that the workers had opened. The radioactive materials were contained in two plastic bags, but they had apparently ripped.
We wish to express our sympathy for the victims of this accident.
This incident is a reminder of the extremely hazardous nature of these materials, especially when they are inhaled, and illustrates why they require such stringent procedures when they are stored and processed.
According to the earliest reports, it was estimated that one worker had inhaled 22,000 becquerels (Bq) of plutonium-239, and 220 Bq of americium-241. (One becquerel of a radioactive substance undergoes one radioactive decay per second.) The others inhaled between 2,200 and 14,000 Bq of plutonium-239 and quantities of americium-241 similar to that of the first worker.
More recent reports have stated that the amount of plutonium inhaled by the most highly exposed worker is now estimated to be 360,000 Bq, and that the 22,000 Bq measurement in the lungs was made 10 hours after the event occurred. Apparently, the plutonium that remains in the body decreases rapidly during the first hours after exposure, as a fraction of the quantity initially inhaled is expelled through respiration. But there are large uncertainties.
The mass equivalent of 360,000 Bq of Pu-239 is about 150 micrograms. It is commonly heard that plutonium is so radiotoxic that inhaling only one microgram will cause cancer with essentially one hundred percent certainty. This is not far off the mark for certain isotopes of plutonium, like Pu-238, but Pu-239 decays more slowly, so it is less toxic per gram. The actual level of harm also depends on a number of other factors. Estimating the health impacts of these exposures in the absence of more information is tricky, because those impacts depend on the exact composition of the radioactive materials, their chemical forms, and the sizes of the particles that were inhaled. Smaller particles become more deeply lodged in the lungs and are harder to clear by coughing. And more soluble compounds will dissolve more readily in the bloodstream and be transported from the lungs to other organs, resulting in exposure of more of the body to radiation. However, it is possible to make a rough estimate.
Using Department of Energy data, the inhalation of 360,000 Bq of Pu-239 would result in a whole-body radiation dose to an average adult over a 50-year period between 580 rem and nearly 4300 rem, depending on the solubility of the compounds inhaled. The material was most likely an oxide, which is relatively insoluble, corresponding to the lower bound of the estimate. But without further information on the material form, the best estimate would be around 1800 rem.
What is the health impact of such a dose? For isotopes such as plutonium-239 or americium-241, which emit relatively large, heavy charged particles known as alpha particles, there is a high likelihood that a dose of around 1000 rem will cause a fatal cancer. This is well below the radiation dose that the most highly exposed worker will receive over a 50-year period. This shows how costly a mistake can be when working with plutonium.
The workers are receiving chelation therapy to try to remove some plutonium from their bloodstream. However, the effectiveness of this therapy is limited at best, especially for insoluble forms, like oxides, that tend to be retained in the lungs.
The workers were exposed when they opened up an old storage can that held materials related to production of fuel from fast reactors. The plutonium facilities at Tokai-mura have been used to produce plutonium-uranium mixed-oxide (MOX) fuel for experimental test reactors, including the Joyo fast reactor, as well as the now-shutdown Monju fast reactor. Americium-241 was present as the result of the decay of the isotope plutonium-241.
I had the opportunity to tour some of these facilities about twenty years ago. MOX fuel fabrication at these facilities was primarily done in gloveboxes through manual means, and we were able to stand next to gloveboxes containing MOX pellets. The gloveboxes represented the only barrier between us and the plutonium they contained. In light of the incident this week, that is a sobering memory.
http://allthingsnuclear.org/elyman/cancer-risk-for-japanese-exposed-to-plutonium#.WTxxfxv-nM0.facebook
June 11, 2017
Posted by dunrenard |
Japan | Exposure, Oarai Research & Development, plutonium, Workers |
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The Oarai Research & Development Center in Ibaraki Prefecture is shown on Wednesday. The facility is overseen by the Japan Atomic Energy Agency.
The five workers exposed to airborne plutonium at the Oarai Research & Development Center in Ibaraki Prefecture were quarantined for about three hours in the room where the accident occurred, a Japan Atomic Energy Agency official said Friday.
Although this action was taken to prevent the plutonium and other radioactive contaminants from spreading to other parts of the nuclear research facility, it probably worsened their internal exposure as they breathed the tainted air.
Internal radiation exposure has been confirmed in four of the five men.
Education and science minister Hirokazu Matsuno said at a news conference Friday that a specially appointed team in the ministry would question JAEA President Toshio Kodama about Tuesday’s accident in the coastal town of Oarai.
The accident occurred inside an analysis room at the facility’s fuel research building around 11:15 a.m. Tuesday when a worker in his 50s opened a sealed metal container that had a plastic container of plutonium and uranium powder samples inside that was double-bagged in plastic. At some point, the bag ruptured, ejecting powder into the air.
JAEA says the tainted floor of the room is giving off 55 becquerels of radiation per square centimeter in the area in front of the apparatus — believed to be a fume hood — in which the container was placed before it was opened. The acceptable level is 4 becquerels, according to the Nuclear Regulation Authority.
The workers waited in the room for 3½ hours after reporting the accident. It was only at 2:44 p.m. that they started being checked for radioactive contamination, JAEA said.
When the accident occurred, the men were wearing masks that covered their noses and mouths, but the checks revealed radioactive material was in the nostrils of each one of them.
Subsequent lung checks showed that the man in his 50s had 22,000 becquerels worth of plutonium-239 in his system, compared with 5,600 to 14,000 becquerels in three of the other four. Four of the five were thus diagnosed with internal radiation exposure.
The metal container, which had not been opened once since it was sealed in 1991, was being checked on the instructions of the NRA. Experts evaluating the accident say it is possible that helium had accumulated in the bag over the years, raising the pressure in the container.
The NRA, the government’s nuclear watchdog, plans to look into the accident, including the manner in which the workers wore their masks.
The metal container in question had never been opened since it was sealed in 1991. The workers were checking the container based on an instruction from the nuclear watchdog. Experts have pointed to the possibility that helium gas had built up inside the bag over the years, raising the pressure inside the container.
http://www.japantimes.co.jp/news/2017/06/09/national/nuclear-workers-quarantined-plutonium-tainted-room-3-hours-accident-jaea/#.WTuQXDekLrf
June 11, 2017
Posted by dunrenard |
Japan | Exposure, Oarai Research & Development, plutonium |
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The technology to fully decontaminate a contaminated land has not yet been invented. Despite of all their efforts and hopes, those farmers’ struggle is just beginning and will last for ages…
Farmers in Fukushima are struggling to revive their livelihoods. The 2011 nuclear accident and subsequent evacuation devastated farms — the area’s main source of jobs.
Some areas, like the village of Iitate, have lifted most of their evacuation orders. But getting back to normal is taking some time.
More than 200 farmers used to raise cows in this region. But 2 months after authorities lifted their evacuation order, few farmers have tried to return to raising animals.
Six cows were released into a paddy field to graze. It’s a step to revive the farm work that was widely seen in Iitate village.
One farmer is using his cows as an experiment that could bring hope to others.
After the animals eat these fields for 2 months, they’ll have their blood tested to check if they have been influenced in any way by radioactive material.
“It’s finally starting. For those who are worried or not confident about resuming cattle raising, I hope what I’m doing will encourage them,” says the farmer, Takeshi Yamada.
Before the accident, farmers in Iitate used to cultivate some 2,300 hectares of land. But this year, only 20 are being used to grow rice and buckwheat.
Some 60 farmers plan to resume farming this year — a small fraction of the previous total.
A major concern behind the slow uptake is the uncertainty farmers have about being able to sell their produce. Surface soil in the area was removed to help decontaminate the ground, but doing that also lowered its fertility.
Another challenge according to farmers is weakened community bonds.
“We used to work together. We were ready to take on whatever tasks we had. But it’s been 6 years, and the motivation to work is low. Nobody now says ‘let’s work together,'” says farmer Koichi Aoki.
To counter their plight, farmers are doing small things.
They formed a group of volunteers to remove weeds. They’re planting flower seeds to beautify the land and keep weeds from coming back. And there’s an even bigger benefit.
“We’ve been protecting our farmland. We want to keep it from turning to wasteland. And by working together, we’ll be able to form human bonds again. That’s our main goal,” says farmer Masuo Nagasho.
It will take time, but people here are hopeful these small steps are just the beginning.
https://www3.nhk.or.jp/nhkworld/en/news/editors/3/fukushimafarmersstruggle/
June 11, 2017
Posted by dunrenard |
Japan | Contamination, Farmers, Fukushima |
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Experts probing the cause of the plutonium-inhalation accident involving five employees at a fuel research facility in Ibaraki Prefecture are trying to determine whether failures in safety equipment or procedures allowed the deadly powder to escape its container.
The accident might have been caused by the long-term buildup of helium emitted by the plutonium, one expert says.
The accident took place at around 11:15 a.m. Tuesday when five men from the Plutonium Fuel Research Facility at Oarai Research & Development Center were taking stock of a radioactive substance in an old storage container. This process usually involves placing the container into a special machine that adjusts the air pressure to prevent the material inside from being blown into the air.
Masked, gloved and donning other protective gear, a worker in his 50s along with a coworker standing by, removed the sealing bolts of a stainless steel container and opened the lid only to see a black powder burst forth.
“The plastic bags were thick and we did not expect them to burst,” said an official at Japan Atomic Energy Agency, the facility’s operator. “I have no idea why (the plutonium powder) flew out of the container,” another said.
The powdery substance had originally been encased in a plastic container double-wrapped in plastic. It was then placed inside a stainless steel container sealed with six bolts. The container had not been opened since 1991, and held about 300 grams of uranium oxide and plutonium oxide that had been used in past experiments, JAEA officials said.
“The container may have been filled with helium (which can be emitted by plutonium) from extended storage, and that may have increased the pressure inside it,” according to Kazuya Idemitsu, an expert on nuclear fuel engineering and a professor at the Graduate School of Engineering at Kyushu University.
Although masks were covering the workers’ noses and mouths, radioactive material was detected inside the noses of three of the exposed employees.
The agency said Wednesday that internal radiation exposure was detected in four of the five workers and that a fifth is suspected as well.
Up to 22,000 becquerels of plutonium were detected in the lungs of the worker in his 50s who opened the lid. Based on that figure, the agency estimates his body has likely has 360,000 becquerels of material inside it overall, they said Thursday.
Under current labor standards, that translates into 1.2 sieverts over a year, and perhaps a 12 sieverts over 50 years, the officials said.
The government allows designated nuclear workers to be exposed to a maximum of 0.05 sievert per year, or 0.1 sievert over five years.
“This is an unusually high amount of radiation. We must carefully look into whether the workers took proper steps,” Nobuhiko Ban, an expert on radiological protection and a member of the Nuclear Regulation Authority, said at an NRA meeting Wednesday.
Plutonium decay can continuously damage cells in the body so it is imperative to make sure workers don’t inhale it, Ban acknowledged.
The main threat from internal plutonium exposure this is bone cancer.
“There are very limited cases of treatment for internal exposure to plutonium in Japan,” Kazuhiko Maekawa, an expert on the subject, said.Gen Suzuki, an expert on radiation epidemiology and professor at the International University of Health and Welfare, said the amount of radiation in their bodies can vary based on the size and character of each particle of plutonium.
March 1997: Radioactive material leaks after a fire and explosion at the Ibaraki branch of now-defunct Power Reactor and Nuclear Fuel Development Corp., later absorbed by Japan Atomic Energy Agency. Thirty-seven employees were exposed.
September 1999: A self-sustaining chain reaction is triggered by the use of mixing buckets at uranium processing firm JCO Co. in the village of Tokai, Ibaraki Prefecture. The accident eventually kills two of three employees, after tainting more than 600 residents.
June 2006: A suspected case of plutonium inhalation occurs at Japan Nuclear Fuel’s reprocessing plant in the village of Rokkasho, Aomori Prefecture, but a check for internal exposure turns out negative.
July 2008: A worker at Global Nuclear Fuel Japan Co. is exposed to uranium in Yokosuka, Kanagawa Prefecture, followed by the exposure of four workers to a uranium-tainted liquid a month later.
March 2011: Three workers stepped in to a puddle during the meltdown crisis at the Fukushima No. 1 power plant, exposing two to high radiation.
May 2013: Thirty-four researchers at JAEA’s Japan Proton Accelerator Research Complex (J-PARC) in Tokai are exposed to an exotic soup of isotopes during an experiment.
http://www.japantimes.co.jp/news/2017/06/08/national/ibaraki-plutonium-exposures-baffle-japanese-nuclear-experts/#.WTuQ9jekLrd
June 11, 2017
Posted by dunrenard |
Japan | Exposure, Ibaraki Prefecture, Oarai Research & Development, plutonium, Workers |
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Question: “Why on earth would anyone do this?”
Answer:”I guess it’s better than sitting unprotected in barrels on the school grounds for years until the national govt got around to classifying the sludge as radioactive waste. And burying it on school grounds has a precedent in Fukushima that everyone seems to think is OK. Why would Yokohama be treated any differently? (Please read in sarcastic tone of voice.)
https://mobile.twitter.com/kanakodo5
https://sites.google.com/site/kanakodo5/home
Special credits to Jack Hiro and Beverly Findley-Kaneko for this information and comments.
June 11, 2017
Posted by dunrenard |
Japan | Burial, Radioactive waste, Schools |
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Japan Minister Denies Government Considering New Nuclear Plants https://www.usnews.com/news/world/articles/2017-06-08/japan-to-consider-building-new-nuclear-plants-nikkei TOKYO (Reuters) 8 June 17 – Japan’s trade minister on Friday denied a media report and said the government is not considering building new nuclear plants or replacing existing reactors.
The Nikkei business daily reported earlier that Japan’s trade ministry would launch a panel as early as this month to revise the country’s energy plan and consider building new nuclear plants or replacing existing plants in the future.
The government will keep its current plan, set up in 2014, to reduce its reliance on nuclear energy, according to the Nikkei report, but also says that keeping nuclear power at a minimal share of the overall energy mix would require the construction of new reactors.
“At this point, we are not thinking of new construction or replacement at all,” Trade Minister Hiroshige Seko told reporters, dismissing the report as groundless.
Seko said the government is discussing the schedule for the revision of its basic energy plan, normally done every three to four years. No details for consideration have been set, he said.
If the government called for a policy that included building new reactors, such a move would face strong public resistance following Japan’s 2011 Fukushima nuclear disaster, the world’s worst nuclear calamity since Chernobyl in 1986.
A target by the industry ministry for nuclear to provide about a fifth of the country’s electricity in 2030 provoked widespread criticism when it was finalised in 2015.
(Reporting by Ami Miyazaki; Writing by Osamu Tsukimori; Editing by Tom Hogue)
June 10, 2017
Posted by Christina Macpherson |
Japan, politics |
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OARAI, Ibaraki — A nuclear research facility here has come under scrutiny after workers were exposed to radiation while checking radioactive materials that had remained in storage for 26 years.
One of the workers exposed to radiation in the accident at the Oarai Research & Development Center of the Japan Atomic Energy Agency (JAEA) on June 6, identified as a male in his 50s, was found with up to 22,000 becquerels of plutonium-239 in his lungs, raising fears he could develop cancer or suffer other health problems.
According to the JAEA, the total level of radioactive materials that entered the man’s blood, bones, organs and other parts of his body was estimated at 360,000 becquerels, based on the amount detected in his lungs.
Problems with safety management at the agency had already been pointed out, and focus is likely to turn toward whether the work at the time of the accident was appropriate.
The agency said that when the worker opened the bolted lid of a steel container during a check, the plastic bag inside ruptured, scattering dust containing uranium and plutonium. Two other workers were next to the worker at the time, assisting in the check.
The some 300 grams of dust was produced when fuel was created for the onsite Joyo experimental fast reactor, which first reached criticality in 1977. It had been placed in a polyethylene container, enclosed in two plastic bags, and then placed in a steel container, where it had been stored since 1991. There were no records to show that the container had been opened before, officials said.
The latest check was being conducted after the Nuclear Regulation Authority had pointed out problems with the management of fuel at another JAEA facility. The JAEA had planned to check 21 steel containers containing uranium and plutonium dust. The accident on June 6 occurred during a check of the first of these containers.
Why did the plastic bag rupture? Kazuya Idemitsu, a professor in the Laboratory of Energy Materials Science at Kyushu University, commented, “Over time, the atomic nuclei of uranium, plutonium and other such substances break down, releasing helium nuclei (alpha rays). When stored over a long time, helium gas would build up, and it’s possible that the pressure inside the container rose, resulting in the rupture.”
Sources close to the JAEA also acknowledged this possibility, with one commenting, “It may not have been a good idea to use a polyethylene container, which had a possibility of rupturing, for storage over a long period.”
On June 7, the Ibaraki prefectural and Oarai municipal governments conducted an on-site inspection of the Oarai Research & Development Center under a nuclear safety agreement. Seventeen officials viewed the inside of the analysis room where the accident occurred through a monitor, and examined the concentration of radioactive materials in expelled air.
Masaaki Kondo, a safety coordinator at the prefectural nuclear power safety division, commented, “We confirmed that the damage did not spread.” The Mito Labor Standards Inspection Office and prefectural police are investigating the cause of the accident and whether the work that led to it was appropriate.
https://mainichi.jp/english/articles/20170608/p2a/00m/0na/018000c
June 9, 2017
Posted by dunrenard |
Japan | Exposure, Ibaraki Prefecture, Oarai Research & Development, radiation, Workers |
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Reactor manufacturers falter, from Toshiba to Areva
Indian Prime Minister Narendra Modi, left, and Japanese counterpart Shinzo Abe reached a final agreement on the nuclear cooperation pact last November.
Japan’s push to increase exports of nuclear technology has been cooled by Toshiba’s Westinghouse problems, undercutting a pillar of Prime Minister Shinzo Abe’s economic growth strategy just as a pact with India comes into effect.
The Diet’s upper house approved a nuclear cooperation deal with India on Wednesday. India plans to boost its nuclear power production capabilities tenfold as economic growth fuels energy demand.
India and Japan began negotiations in 2010, reaching an agreement in November when Indian Prime Minister Narendra Modi visited Abe. Japan will revise related directives for its Nuclear Regulation Authority. India already greenlighted the pact, which takes effect once both countries notify each other of such approval. This could happen as early as July.
India has 22 nuclear plants in operation and five under construction, the International Atomic Energy Agency says. The country plans to source one-quarter of its energy from nuclear power by 2050.
“Population and economic growth will further strain energy supply and demand,” said Satoshi Shimizu of the Japan Research Institute. “There is a lot of room for Japan to export nuclear power.”
But Japan’s export efforts have not gone according to plan. In June 2016, the U.S. and India reached a basic agreement on a deal commissioning Toshiba’s American subsidiary Westinghouse Electric to build six nuclear reactors. Japan had rushed to finalize the pact with India since Toshiba would be involved in supplying parts, but Westinghouse’s bankruptcy protection filing in March has thrown the conglomerate into crisis.
More global headwinds buffet the industry. Severe delays in the construction of nuclear power facilities by France’s Areva have ballooned losses, with the French government now leading the company’s reorganization. Vietnam canceled nuclear energy plans in November due to financial reasons and local opposition.
“Conditions have changed due to Toshiba and other issues,” said Takeo Kitsukawa, a professor at Tokyo University of Science. “The first issue is how to get [nuclear reactor] manufacturers back on their feet.”
A separate document indicates that Japan will cease cooperation should India break a 2008 pledge, made by its foreign minister at the time, to suspend nuclear tests. India has maintained its moratorium on nuclear testing since 1998.
Japan’s opposition Democratic Party disapproves of the India deal because the provision halting cooperation is not included in the agreement itself, and thus may offer insufficient legal guarantees limiting nuclear technology exports to peaceful uses. Opposition parties also worry that India is not a member of the Treaty on the Non-Proliferation of Nuclear Weapons.
http://s.nikkei.com/2sEJqcu
June 9, 2017
Posted by dunrenard |
Japan | India, Nuclear Exports |
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‘No one has inhaled this much plutonium’: 5 staff exposed to radiation in Japan lab accident
Japanese authorities are unsure about the medical prognosis for five staffers who inhaled toxic plutonium after mishandling it at the Oarai Research and Development Center outside Tokyo.
“As far as I can remember, no one has inhaled plutonium at this level,” said Ishikawa Keiji, a security official at the Japan Atomic Energy Agency (JAEA) which oversees the lab, cited by the Jiji Press news agency.
The accident occurred at 11:15am on Tuesday in the analysis room of the facility dedicated to researching improved nuclear fuel for its fast reactors.
One of the five men opened a metallic cylinder where the fuel, a mixture of uranium and plutonium, is stored before and after experiments. In the process, the double plastic wrapping inside which the radioactive material is kept ripped, and the toxic substance burst into the air.
Shunichi Tanaka, chairman of the Nuclear Regulation Authority (NRA), which has frequently criticized the JAEA for the conditions at its facilities, said “workplace complacency” was possibly to blame.
The NRA said the workers had never experienced a similar plastic rip before, and as a result, did not feel the need to complete their research in a tightly sealed environment.
The researcher responsible for opening the box, described as a man in his 50s, had 22,000 becquerels of plutonium-239 detected in his lungs, and the other four between 2,200 and 14,000 becquerels.
Officials said the five staff have not yet complained of health problems with one assuring that “the amount is not enough to cause acute radiation damage,” according to the Japanese newspaper The Asahi Shimbun.
The longer-term predictions were less definitive, however.
“Detection of 22,000 becquerels is a situation that cannot be easily brushed aside. It is no small amount, although it may not be life-threatening,” said Nobuhiko Ban, an NRA radiological protection specialist, quoted by The Asahi Shimbun.
The five have been injected with a substance that speeds up the discharge of radioactive materials and remain under observation at the National Institutes for Quantum and Radiological Science and Technology.
The NRA has previously said that JEAA was “unfit” to operate an accident-plagued prototype reactor at Monju and has also faced accusations of poor handling of radioactive materials at another site.
But a use for Japan’s large plutonium stockpile must be found, and there are currently plans for utilizing MOX fuel – a mixture of plutonium and uranium, such as that involved in the latest accident – to power conventional reactors instead of the low-enriched uranium that they were designed for.
https://www.rt.com/news/391283-japan-nuclear-accident-plutonium/
‘No one has inhaled this much plutonium’: 5 staff exposed to radiation in Japan lab accident
Japanese authorities are unsure about the medical prognosis for five staffers who inhaled toxic plutonium after mishandling it at the Oarai Research and Development Center outside Tokyo.
“As far as I can remember, no one has inhaled plutonium at this level,” said Ishikawa Keiji, a security official at the Japan Atomic Energy Agency (JAEA) which oversees the lab, cited by the Jiji Press news agency.
The accident occurred at 11:15am on Tuesday in the analysis room of the facility dedicated to researching improved nuclear fuel for its fast reactors.
One of the five men opened a metallic cylinder where the fuel, a mixture of uranium and plutonium, is stored before and after experiments. In the process, the double plastic wrapping inside which the radioactive material is kept ripped, and the toxic substance burst into the air.
Shunichi Tanaka, chairman of the Nuclear Regulation Authority (NRA), which has frequently criticized the JAEA for the conditions at its facilities, said “workplace complacency” was possibly to blame.
The NRA said the workers had never experienced a similar plastic rip before, and as a result, did not feel the need to complete their research in a tightly sealed environment.
The researcher responsible for opening the box, described as a man in his 50s, had 22,000 becquerels of plutonium-239 detected in his lungs, and the other four between 2,200 and 14,000 becquerels.
Officials said the five staff have not yet complained of health problems with one assuring that “the amount is not enough to cause acute radiation damage,” according to the Japanese newspaper The Asahi Shimbun.
The longer-term predictions were less definitive, however.
“Detection of 22,000 becquerels is a situation that cannot be easily brushed aside. It is no small amount, although it may not be life-threatening,” said Nobuhiko Ban, an NRA radiological protection specialist, quoted by The Asahi Shimbun.
The five have been injected with a substance that speeds up the discharge of radioactive materials and remain under observation at the National Institutes for Quantum and Radiological Science and Technology.
The NRA has previously said that JEAA was “unfit” to operate an accident-plagued prototype reactor at Monju and has also faced accusations of poor handling of radioactive materials at another site.
But a use for Japan’s large plutonium stockpile must be found, and there are currently plans for utilizing MOX fuel – a mixture of plutonium and uranium, such as that involved in the latest accident – to power conventional reactors instead of the low-enriched uranium that they were designed for.
https://www.rt.com/news/391283-japan-nuclear-accident-plutonium/
High level of radiation found in lungs of nuclear facility worker
OARAI, Ibaraki — A worker at a research and development (R&D) center here has been found to have a high level of radioactive material — up to 22,000 becquerels — in his lungs following exposure to radiation, the center said on June 7.
The discovery came after five workers at the Oarai Research & Development Center, which belongs to the Japan Atomic Energy Agency, were exposed to radioactive materials on June 6.
Radioactive materials are difficult to expunge from the human body, and it is thought that the level of internal exposure in this case will be 1.2 sieverts in one year, and 12 sieverts over 50 years.
The five workers have been taken to the National Institutes of Radiological Sciences in Chiba Prefecture, where they are undergoing examinations.
At a Nuclear Regulation Authority (NRA) meeting on June 7, a committee member said the workers’ situation is “not mild.”
According to organizations such as the NRA, one of the five workers was found to have up to 22,000 becquerels of plutonium-239 and 220 becquerels of americium-241 in his lungs. Two other workers were discovered to have 12 becquerels and 130 becquerels of americium-241 in their lungs, respectively. All five workers were administered medicine designed to reduce the radiation dose of the internal exposure.
The five workers were all wearing protective clothing and face masks at the time of the radiation exposure, the R&D center said. It is currently being investigated whether or not there were any problems at the time the incident happened.
Plutonium and americium are both harmful to human bodies as they emit alpha rays.
http://mainichi.jp/english/articles/20170607/p2a/00m/0na/018000c
Four workers exposed to radioactive materials at Ibaraki nuclear facility
Four workers suffered internal radiation exposure due to inhalation of a large amount of plutonium during an inspection at a nuclear research facility in Ibaraki Prefecture on Tuesday, the operator of the facility said Wednesday.
In the wake of what appears to be an unprecedented internal radiation exposure accident, the state’s nuclear safety regulator and local labor authorities inspected the scene to see if there were any flaws in safety management.
The accident occurred at the fuel research building of the Japan Atomic Energy Agency’s Oarai Research & Development Center when a bag covering a container for nuclear fuel materials, including powder samples of plutonium and uranium, tore during inspection on Tuesday.
Up to 22,000 becquerels of plutonium 239 were detected in the lungs of a male worker in his 50s. Up to 14,000 becquerels of radioactive materials were found in the three other workers, officials of the Japan Atomic Energy Agency said.
The Nuclear Regulation Authority said the worker with the higher reading has been exposed to an extreme amount of radiation and the situation is considered grave.
While none of the workers have complained of health problems so far, an official with the facility’s operator said it “cannot rule out the possibility of future health effects.”
The agency assumes that the amount of radiation exposure of the male worker in his 50s translates to up to 12 sieverts over 50 years, well above the legal limit set for workers who deal with radiation.
For its part, the labor office said that it estimates the man with the highest exposure to radiation has exceeded the annual limit of radiation exposure, which is 50 millisieverts a year and 100 millisieverts in five years.
Plutonium is known to emit alpha rays over a long period, damaging surrounding organs and tissues. If it is deposited into the lungs, it could increase the risk of developing cancer
The five workers have been transported to the National Institute of Radiological Sciences and given medication to help discharge radioactive materials from their bodies.
“I saw such a (high) figure for the first time,” said Makoto Akashi, a senior official at the National Institutes for Quantum and Radiological Science and Technology, referring to the reading of 22,000 becquerels. The institute oversees the National Institute of Radiological Sciences.
“It is very clear from a scientific viewpoint that the internal exposure to radiation would increase the risk of cancer (for the workers),” Akashi said.
“I have never heard of such a large amount as a reading for internal exposure to radiation,” Shunichi Tanaka, who heads the NRA, told a separate news conference.
The workers wore masks but could have inhaled radioactive material from the small gaps between the masks and their faces.
Kunikazu Noguchi, an expert on radiological protection and associate professor at Nihon University, said it is hard to conclude the impact of the 22,000 becquerels, as the actual amount of radioactive substances he inhaled is still unknown.
“It is possible, however, that the worker could have been exposed to more radioactive materials than the legally allowable maximum limit,” Noguchi said. He said it is necessary to get to the bottom of the incident, especially whether workers followed guidelines, as it is hard to imagine a plastic bag containing nuclear substances could tear in such a facility as the Oarai center.
http://www.japantimes.co.jp/news/2017/06/07/national/five-workers-exposed-radioactive-materials-ibaraki-nuclear-facility/#.WTkK8zekLrc
Worker at Ibaraki facility has up to 22,000 becquerels of plutonium in lungs
TOKYO – Five workers have suffered internal radiation exposure, with one found with up to 22,000 becquerels of plutonium in his lungs, following an inspection accident at a nuclear research facility in Ibaraki Prefecture on Tuesday, the operator of the facility said Wednesday.
In one of the worst accidents involving internal radiation exposure in Japan, up to 5,600 to 14,000 becquerels of plutonium 239 have been detected from the other three workers, the Japan Atomic Energy Agency said.
The accident occurred at the fuel research building of the agency’s Oarai Research & Development Center when a bag covering a container for nuclear fuel materials, including powder samples of plutonium and uranium, tore during inspection.
A labor standards inspection office in Ibaraki conducted an inspection Tuesday and Wednesday at the building, while the Nuclear Regulation Authority, the nuclear safety watchdog, also dispatched an inspector to the scene to check whether there were any violations of safety regulations.
The agency estimates that the amount of radiation exposure of the man with the highest level translates to up to 12 sieverts over 50 years.
The labor office believes that the man in his 50s has exceeded the annual limit of radiation exposure of 0.1 sievert in five years set for those who handle radioactive materials.
Plutonium is known to emit alpha rays for a long period, damaging surrounding organs and tissues. If it is deposited into the lungs, it could increase the risk of developing cancer.
The Japan Atomic Energy Agency has said the operation by the workers was carried out as usual.
Nuclear Regulation Authority Chairman Shunichi Tanaka said of the incident at a press conference, “Perhaps (the workers) have become too accustomed to plutonium. I urge careful handling.”
“As (a level for) internal radiation exposure it’s an amount unheard of,” he said.
“We shouldn’t downplay the situation,” said NRA Commissioner Nobuhiko Ban, a specialist in radiological protection.
While none of the workers has complained of health problems so far, an official of the facility operator said it “cannot rule out the possibility of future health effects.”
The five workers have been transported to the National Institute of Radiological Sciences and given medication to facilitate the discharge of radioactive materials from their bodies.
Since radioactive materials were found on hands and faces of four of the five workers, they have been decontaminated, said an official of the National Institutes for Quantum and Radiological Science and Technology, an umbrella organization of the National Institute of Radiological Sciences.
The workers wore masks to cover their mouths and noses but could have inhaled the radioactive materials from the small gaps between the masks and their faces.
The Japan Atomic Energy Agency has previously come under criticism for lacking safety awareness, following revelations of a massive number of equipment inspection failures at its Monju prototype fast-breeder nuclear reactor in Fukui Prefecture.
The Japanese government decided to decommission Monju last year after it has barely operated over the past two decades despite its envisioned key role in the country’s nuclear fuel recycling policy.
https://japantoday.com/category/national/5-workers-suffer-radiation-exposure-one-with-up-to-22-000-becquerels-of-plutonium-in-his-lungs#.WTh8DhaVAOw.facebook
June 9, 2017
Posted by dunrenard |
Japan | Exposure, Ibaraki Prefecture, Oarai Research & Development, plutonium, radiation, Workers |
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