Month: May 2018

Novel Method of Quantifying Radioactive Cesium-Rich Microparticles (CsMPs) in the Environment from the Fukushima Daiichi Nuclear Power Plant

Japan, Nuclear, Radiation
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Novel Method of Quantifying Radioactive Cesium-Rich Microparticles (CsMPs) in the Environment from the Fukushima Daiichi Nuclear Power Plant” has been published in the journal of Environmental Science:
Highly radioactive cesium-rich microparticles (CsMPs) were released from the Fukushima Daiichi nuclear power plant (FDNPP) to the surrounding environment at an early stage of the nuclear disaster in March of 2011; however, the quantity of released CsMPs remains undetermined. Here, we report a novel method to quantify the number of CsMPs in surface soils at or around Fukushima and the fraction of radioactivity they contribute, which we call “quantification of CsMPs” (QCP) and is based on autoradiography. Here, photostimulated luminescence (PSL) is linearly correlated to the radioactivity of various microparticles, with a regression coefficient of 0.0523 becquerel/PSL/h (Bq/PSL/h). In soil collected from Nagadoro, Fukushima, Japan, CsMPs were detected in soil sieved with a 114 μm mesh. There was no overlap between the radioactivities of CsMPs and clay particles adsorbing Cs. Based on the distribution of radioactivity of CsMPs, the threshold radioactivity of CsMPs in the size fraction of <114 μm was determined to be 0.06 Bq. Based on this method, the number and radioactivity fraction of CsMPs in four surface soils collected from the vicinity of the FDNPP were determined to be 48–318 particles per gram and 8.53–31.8%, respectively. The QCP method is applicable to soils with a total radioactivity as high as ∼106 Bq/kg. This novel method is critically important and can be used to quantitatively understand the distribution and migration of the highly radioactive CsMPs in near-surface environments surrounding Fukushima.

Fukushima-Daiichi radioactive particle release was significant says new research

Japan, Nuclear, Radiation
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24 May 2018
Fukushima-Daiichi radioactive particle release was significant says new research
Scientists say there was a significant release of radioactive particles during the Fukushima-Daiichi nuclear accident.
The researchers identified the contamination using a new method and say if the particles are inhaled they could pose long-term health risks to humans.
The new method allows scientists to quickly count the number of caesium-rich micro-particles in Fukushima soils and quantify the amount of radioactivity associated with these particles.
The research, which was carried out by scientists from Kyushu University, Japan, and The University of Manchester, UK, was published in Environmental Science and Technology.
In the immediate aftermath of the Fukushima Daiichi nuclear accident, it was thought that only volatile, gaseous radionuclides, such as caesium and iodine, were released from the damaged reactors. However, in recent years it has become apparent that small radioactive particles, termed caesium-rich micro-particles, were also released. Scientists have shown that these particles are mainly made of glass, and that they contain significant amounts of radioactive caesium, as well as smaller amounts of other radioisotopes, such as uranium and technetium.
The abundance of these micro-particles in Japanese soils and sediments, and their environmental impact is poorly understood. But the particles are very small and do not dissolve easily, meaning they could pose long-term health risks to humans if inhaled.
Therefore, scientists need to understand how many of the micro-particles are present in Fukushima soils and how much of the soil radioactivity can be attributed to the particles. Until recently, these measurements have proven challenging.
The new method makes use of a technique that is readily available in most Radiochemistry Laboratories called Autoradiography. In the method, an imaging plate is placed over contaminated soil samples covered with a plastic wrap, and the radioactive decay from the soil is recorded as an image on the plate. The image from plate is then read onto a computer.
“We now need to push forward and better understand if caesium micro-particles are abundant throughout not only the exclusion zone, but also elsewhere in the Fukushima prefecture; then we can start to gauge their impact”. 
Dr Gareth Law
 
The scientists say radioactive decay from the caesium-rich micro particles can be differentiated from other forms of caesium contamination in the soil.
The scientists tested the new method on rice paddy soil samples retrieved from different locations within the Fukushima prefecture. The samples were taken close to (4 km) and far away (40 km) from the damaged nuclear reactors. The new method found caesium-rich micro-particles in all of the samples and showed that the amount of caesium associated with the micro-particles in the soil was much larger than expected.
Dr Satoshi Utsunomiya, Associate Professor at Kyushu University, Japan, and the lead author of the study says “when we first started to find caesium-rich micro-particles in Fukushima soil samples, we thought they would turn out to be relatively rare. Now, using this method, we find there are lots of caesium-rich microparticles in exclusion zone soils and also in the soils collected from outside of the exclusion zone”.
Dr Gareth Law, Senior Lecturer in Analytical Radiochemistry at the University of Manchester and an author on the paper, adds: “Our research indicates that significant amounts of caesium were released from the Fukushima Daiichi reactors in particle form.
“This particle form of caesium behaves differently to the other, more soluble forms of caesium in the environment. We now need to push forward and better understand if caesium micro-particles are abundant throughout not only the exclusion zone, but also elsewhere in the Fukushima prefecture; then we can start to gauge their impact”.
The new method can be easily used by other research teams investigating the environmental impact of the Fukushima Daiichi accident.
Dr Utsunomiya adds: “we hope that our method will allow scientists to quickly measure the abundance of caesium-rich micro-particles at other locations and estimate the amount of caesium radioactivity associated with the particles. This information can then inform cost effective, safe management and clean-up of soils contaminated by the nuclear accident”.
 
The paper, ‘Novel Method of Quantifying Radioactive Cesium-Rich Microparticles (CsMPs) in the Environment from the Fukushima Daiichi Nuclear Power Plant’ has been published in the journal of Environmental Science – DOI:10.1021/acs.est.7b06693
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Nuclear issue again takes center stage in Niigata election

Japan, Nuclear
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The three independent candidates for Niigata governor are, from left: Chikako Ikeda, Hideyo Hanazumi and Satoshi Annaka.
 
May 25, 2018
NIIGATA–The election for a new governor of Niigata Prefecture was triggered by a sex scandal, but the key issue facing voters is where the candidates stand on restarting the Kashiwazaki-Kariwa nuclear power plant, one of the world’s biggest nuclear facilities.
Campaigning officially kicked off May 24.
The outcome of the June 10 vote could have a bearing on the Abe administration’s moves to bring more nuclear plants back online.
Although the candidates are running as independents, two are supported by political parties.
In early speeches, they all outlined their position on the nuclear plant operated by Tokyo Electric Power Co., but residents are calling on them to be less cautious and state where they truly stand.
“Many people are still suffering (because of the Fukushima nuclear disaster), and there are still many people living as evacuees,” said a female resident, 66. “Some kids have even been bullied. So I really want the candidates to state clearly that Niigata doesn’t need a nuclear plant anymore.”
On the other hand, a 70-year-old female resident argued that local people “cannot flatly oppose the restart of the nuclear plant because of the impact it will have on economy.”
For this reason, she said, “I cannot easily say I am against it.”
The election is expected to come down to a battle between Hideyo Hanazumi, 60, a former vice commandant of the Japan Coast Guard, and Chikako Ikeda, 57, a former member of the prefectural assembly.
Hanazumi is supported by the ruling coalition of the Liberal Democratic Party and Komeito, while Ikeda is backed by five opposition parties.
The other candidate is Satoshi Annaka, 40, a former member of the Gosen municipal assembly.
The election was triggered by the April resignation of Ryuichi Yoneyama after he admitted to paying women for sexual favors.
Yoneyama, 50, had taken a cautious stance on restarting the Kashiwazaki-Kariwa complex.
Hanazumi declared that he would take over an investigation started by Yoneyama to understand the fundamental cause of the triple meltdown at the Fukushima No. 1 nuclear plant in 2011, and reach his decision on the issue when the investigation ends in several years.
Ikeda stressed the significance of reviewing the Fukushima nuclear disaster, stating that continuing with the investigation is “the most basic of basics.”
She said the matter must be pursued rigorously.
Ikeda added that she would make a final decision on the restart issue after careful discussions with residents and other parties.
“I will seek a zero-nuclear Niigata Prefecture,” she said.

Cattle return to graze in Fukushima village for 1st time since nuke plant meltdowns

Japan, Nuclear, Radiation
Soon to reach our tables deliciously hot!!!
 
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Farmer Takeshi Yamada lets his beef cattle graze in the village of Iitate on May 23, 2018, for the first time since the Fukushima nuclear disaster.
 
May 24, 2018
IITATE, Fukushima — Farmers began tests on having their cattle graze here on May 23 for the first time since the March 2011 triple meltdown at the Fukushima No. 1 nuclear plant.
The national government lifted the nuclear evacuation order in most parts of the village at the end of March 2017.
While about 220 farmers bred beef cattle before the nuclear disaster, just five farmers restarted their breeding after the ban was lifted. The test will last over three months, and the farmers will check the level of radiation in the cattle’s blood and conduct other checks with the aim to return to regular grazing in 2019 or later.
Farmer Takeshi Yamada, 69, who had six of his beef cows graze on the green grass, commented, “Grazing is less stressful than breeding in barns. It makes it possible to produce fresh beef.” Yamada will strive to revive the local “Iitate Beef Cattle” brand.

Air duct corrosion and holes found at seven nuclear plants

Japan, Nuclear, Radiation

n-reactors-a-20180524.jpgCorrosion is seen in a ventilation duct at the No. 3 unit of the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture. | NUCLEAR REGULATION AUTHORITY

 
Corrosion and holes have been found in ventilation ducts at 12 reactors at seven nuclear plants across the country, the Nuclear Regulation Authority said Wednesday, raising concerns that workers could be exposed to radiation in the event of an accident.
The governmental nuclear watchdog released the results of a nationwide survey it had ordered following a revelation in December 2016 that corrosion had left multiple holes in the air ducts of the No. 2 reactor at Chugoku Electric Power Co.’s Shimane plant in western Japan. That reactor was not included in the survey.
Serious corrosion was found at the No. 3 unit of the Kashiwazaki-Kariwa plant in Niigata Prefecture operated by Tokyo Electric Power Company Holdings Inc. and may have abnormally affected ventilation of the central control room, the watchdog said.
Although the No. 7 unit at the same plant has passed a test to resume operation, the NRA said it will inspect the impact of any corrosion found at the reactor. No abnormality associated with corrosion has been found at the remaining 10 units, it said.
Corrosion or holes were found in steel or galvanized steel ducts at Tohoku Electric Power Co.’s Onagawa nuclear plant, Japan Atomic Power Co.’s Tokai No. 2 nuclear plant, Tepco’s Fukushima No. 1 nuclear plant and Kashiwazaki-Kariwa nuclear plant, Chubu Electric Power Co.’s Hamaoka plant, Hokuriku Electric Power Co.’s Shiga nuclear plant and Chugoku Electric’s Shimane plant.
If an accident occurs, radioactive materials could flow into a plant’s central control room through such holes, putting workers in danger of radiation exposure.
At the No. 3 reactor at the Kashiwazaki-Kariwa plant, a crack as large as 13 centimeters in length and 5 cm in width was found. A total of nine holes and cracks have been discovered at the Nos. 3 and 7 units at the plant.
All the reactors with corrosion were boiling-water reactors, the same type used at the Fukushima No. 1 plant, which spewed a massive amount of radioactive material into the atmosphere following the March 2011 earthquake and tsunami.
No problems have been detected at pressurized-water nuclear reactors, as filtering and other measures take place near air inlets.
The holes at the No. 2 unit at the Shimane plant were discovered when insulation materials covering the ducts were removed for inspection.
The holes, the largest of which measured about 100 centimeters wide and about 30 centimeters long, are believed to have been caused by dew condensation and rainwater that seeped inside the building, as well as salt deposits on the ducts, given that the corrosion extended about 50 meters from the air inlet and spread from the inner surface of the ducts.
Chugoku Electric has decided to increase the number of inspection points at sections near fresh-air inlets and bolster anti-corrosion measures, including the installation of a dehumidifier.

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Japanese 100-yen shop slapped with fine, 2-year import ban in Taiwan

Japan, Nuclear, Radiation

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TAIPEI (Kyodo) — Taiwan authorities said Wednesday that Japanese 100-yen shop chain Daiso has been fined NT$41.64 million (US$1.38 million) for falsifying import application documents and banned from importing goods from Japan for two years.

Foreign Trade Bureau deputy chief Lee Guann-jyh told a legislative committee that the punishments have been meted out to Hiroshima-based Daiso Industries Co., which has been operating in Taiwan since 2001 and has about 60 stories here.
 
In November 2015, Daiso received a six-month import ban for having illegally imported food products from parts of Japan affected by 2011 Fukushima nuclear disaster between July 2014 and March 2015, and selling them with falsified labels of origin.
 
During that six-month period, Daiso could still import goods from Japan on a case-by-case basis after obtaining permission from the bureau.
 
But in doing so, it falsified the dates of the imported goods, altering them to predate the six-month ban period that began in November 2015. A total of 694 import application documents were fraudulent, according to the bureau.
On April 27, the company held a press conference in which it apologized to Taiwanese consumers.
 

Japan’s government weighs dumping radioactive Fukushima water into the Pacific

Japan, Nuclear, Radiation
As the cleanup of a triple meltdown following an earthquake and tsunami at the Fukushima nuclear power plant drags into its seventh year, one of the biggest continuing threats is less from airborne radioactivity than it is simple water.
 
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A waterlogged radiation and tsunami warning sign found on Fukushima beaches in 2013.
May 22, 2018
As the cleanup of a triple meltdown following an earthquake and tsunami at the Fukushima nuclear power plant drags into its seventh year, one of the biggest continuing threats is less from airborne radioactivity than it is simple water.
On March 11, 2011, the Fukushima plant was devastated by a tsunami, which over the ensuing days sent three of its six reactors into meltdown, while hydrogen explosions cast radioactive iodine, cesium and other fission by-products into the air. More than 160,000 people were forced to evacuated in the wake of the disaster, which has now become synonymous with Chernobyl.
At the time, officials began pumping millions of liters of water into the destroyed reactors to keep them cool, often dumping it from helicopters and spraying it through water cannons. In the years since, the water inundation has become less dramatic, but in the absence of any other way to keep the molten fuel cool, the flow of water continues to flow through the remains of the reactors at the rate of some 160 tons of water a day.
While much of that water undergoes purification to remove significant amounts of radiation, filters can’t cleanse the water of tritium, a radioactive isotope of hydrogen — a process likened by some scientists to separating water from water.
As a result, water contaminated with tritium is building up and space to store it at the disaster site is running out. Of the 1.13 million-ton water storage capacity that the plant has, some 1.7 million tons have been used up.
Cleanup workers have to build a new steel water tank at the rate of one every four days to contain it all, and space to build more is becoming scarce. According to Japan’s Ministry of Economy, Trade and Industry, the tanks already sprawl over an area that could accommodate 32 football fields. All of the storage, says the government, will run out by 2021.
This looming crisis has left the Japanese government and Tokyo Electric Power Company, which owns Fukushima,  pondering how to get rid of this water – a decision that is generating anxiety and scare headlines as an expert committee weighs whether or not to release the water into the Pacific Ocean.
Despite the national and worldwide case of nerves such a decision might provoke the Japanese government says it can do it without a threat to the country’s fishing industry. Tritium, after all, is a substance that naturally occurs in rivers and seabeds – even tap water. What’s problematic with the tritium at Fukushima, though, is that its levels in the Fukushima water are 10 times higher than Japanese national standards for dumping it.
Because of that, the government’s expert panel is considering several methods for the water’s disposal, including evaporating it, releasing it into the sea after electrolysis, burying it underground or injecting it deep into the geology.
But as cleanup costs continue to spiral, with some Japanese think tanks speculating the final bill could be as much as $470 billion to $660 billion,  releasing the water into the sea – after diluting it – may turn out to be the cheapest option.
It’s not the first battle against water that the cleanup effort has fought. As recently as two years ago, some 400 tons of ground water flowed into the facility daily. Tokyo Electric Power somewhat stemmed that by building an underground wall of frozen soil to staunch the seepage of radioactive water.
has managed to decrease the inflow by installing a 30-yard-long “ice wall” fence that freezing cold brine is pumped through to freeze the soil around it, reports Wired. The chilled soil is meant to create a barrier to keep additional groundwater from spilling into the radioactive area.
But this year, on the seventh anniversary of the disaster, an expert group commissioned by the Japanese government concluded that the subterranean wall is not entirely effective against the deluge, and that other methods of battling leakage have to be devised.