Move over Chernobyl, Fukushima is now officially the worst nuclear power disaster in history — CounterPunch

” The radiation dispersed into the environment by the three reactor meltdowns at Fukushima-Daiichi in Japan has exceeded that of the April 26, 1986 Chernobyl catastrophe, so we may stop calling it the “second worst” nuclear power disaster in history. Total atmospheric releases from Fukushima are estimated to be between 5.6 and 8.1 times that of Chernobyl, according to the 2013 World Nuclear Industry Status Report. Professor Komei Hosokawa, who wrote the report’s Fukushima section, told London’s Channel 4 News then, “Almost every day new things happen, and there is no sign that they will control the situation in the next few months or years.”

Tokyo Electric Power Co. has estimated that about 900 peta-becquerels have spewed from Fukushima, and the updated 2016 TORCH Report estimates that Chernobyl dispersed 110 peta-becquerels. (A Becquerel is one atomic disintegration per second. The “peta-becquerel” is a quadrillion, or a thousand trillion Becquerels.)

Chernobyl’s reactor No. 4 in Ukraine suffered several explosions, blew apart and burned for 40 days, sending clouds of radioactive materials high into the atmosphere, and spreading fallout across the whole of the Northern Hemisphere — depositing cesium-137 in Minnesota’s milk.

The likelihood of similar or worse reactor disasters was estimated by James Asselstine of the Nuclear Regulatory Commission (NRC), who testified to Congress in 1986: “We can expect to see a core meltdown accident within the next 20 years, and it … could result in off-site releases of radiation … as large as or larger than the releases … at Chernobyl. Fukushima-Daiichi came 25 years later.

Contamination of soil, vegetation and water is so widespread in Japan that evacuating all the at-risk populations could collapse the economy, much as Chernobyl did to the former Soviet Union. For this reason, the Japanese government standard for decontaminating soil there is far less stringent than the standard used in Ukraine after Chernobyl.

Fukushima’s Cesium-137 Release Tops Chernobyl’s

The Korea Atomic Energy Research (KAER) Institute outside of Seoul reported in July 2014 that Fukushima-Daiichi’s three reactor meltdowns may have emitted two to four times as much cesium-137 as the reactor catastrophe at Chernobyl.

To determine its estimate of the cesium-137 that was released into the environment from Fukushima, the Cesium-137 release fraction (4% to the atmosphere, 16% to the ocean) was multiplied by the cesium-137 inventory in the uranium fuel inside the three melted reactors (760 to 820 quadrillion Becquerel, or Bq), with these results:

Ocean release of cesium-137 from Fukushima (the worst ever recorded): 121.6 to 131.2 quadrillion Becquerel (16% x 760 to 820 quadrillion Bq). Atmospheric release of Cesium-137 from Fukushima: 30.4 to 32.8 quadrillion Becquerel (4% x 760 to 820 quadrillion Bq).

Total release of Cesium-137 to the environment from Fukushima: 152 to 164 quadrillion Becquerel. Total release of Cesium-137 into the environment from Chernobyl: between 70 and 110 quadrillion Bq.

The Fukushima-Daiichi reactors’ estimated inventory of 760 to 820 quadrillion Bq (petabecquerels) of Cesium-137 used by the KAER Institute is significantly lower than the US Department of Energy’s estimate of 1,300 quadrillion Bq. It is possible the Korean institute’s estimates of radioactive releases are low.

In Chernobyl, 30 years after its explosions and fire, what the Wall St. Journal last year called “the $2.45 billion shelter implementation plan” was finally completed in November 2016. A huge metal cover was moved into place over the wreckage of the reactor and its crumbling, hastily erected cement tomb. The giant new cover is 350 feet high, and engineers say it should last 100 years — far short of the 250,000-year radiation hazard underneath.

The first cover was going to work for a century too, but by 1996 was riddled with cracks and in danger of collapsing. Designers went to work then engineering a cover-for-the-cover, and after 20 years of work, the smoking radioactive waste monstrosity of Chernobyl has a new “tin chapeau.” But with extreme weather, tornadoes, earth tremors, corrosion and radiation-induced embrittlement it could need replacing about 2,500 times. ”

by John LaForge, CounterPunch

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Clearing the radioactive rubble heap that was Fukushima Daiichi, 7 years on — Scientific American

” Seven years after one of the largest earthquakes on record unleashed a massive tsunami and triggered a meltdown at Japan’s Fukushima Daiichi nuclear power plant, officials say they are at last getting a handle on the mammoth task of cleaning the site before it is ultimately dismantled. But the process is still expected to be a long, expensive slog, requiring as-yet untried feats of engineering—and not all the details have yet been worked out.

When the disaster knocked out off- and on-site power supplies on March 11, 2011, three of the cooling systems for the plant’s four reactor units were disabled. This caused the nuclear fuel inside to overheat, leading to a meltdown and hydrogen explosions that spewed out radiation. The plant’s operator, Tokyo Electric Power Co. (TEPCO), responded by cooling the reactors with water, which continues today. Meanwhile thousands of people living in the surrounding area were evacuated and Japan’s other nuclear plants were temporarily shut down.

In the years since the disaster and the immediate effort to stanch the release of radioactive material, officials have been working out how to decontaminate the site without unleashing more radiation into the environment. It will take a complex engineering effort to deal with thousands of fuel rods, along with the mangled debris of the reactors and the water used to cool them. Despite setbacks, that effort is now moving forward in earnest, officials say. “We are still conducting studies on the location of the molten fuel, but despite this we have made the judgment that the units are stable,” says Naohiro Masuda, TEPCO’s chief decommissioning officer for Daiichi.

Completely cleaning up and taking apart the plant could take a generation or more, and comes with a hefty price tag. In 2016 the government increased its cost estimate to about $75.7 billion, part of the overall Fukushima disaster price tag of $202.5 billion. The Japan Center for Economic Research, a private think tank, said the cleanup costs could mount to some $470 billion to $660 billion, however.

Under a government roadmap, TEPCO hopes to finish the job in 30 to 40 years. But some experts say even that could be an underestimate. “In general, estimates of work involving decontamination and disposal of nuclear materials are underestimated by decades,” says Rod Ewing, a professor of nuclear security and geological sciences at Stanford University. “I think that we have to expect that the job will extend beyond the estimated time.”

The considerable time and expense are due to the cleanup being a veritable hydra that involves unprecedented engineering. TEPCO and its many contractors will be focusing on several battlefronts.

Water is being deliberately circulated through each reactor every day to cool the fuel within—but the plant lies on a slope, and water from precipitation keeps flowing into the buildings as well. Workers built an elaborate scrubbing system that removes cesium, strontium and dozens of other radioactive particles from the water; some of it is recirculated into the reactors, and some goes into row upon row of giant tanks at the site. There’s about one million tons of water kept in 1,000 tanks and the volume grows by 100 tons a day, down from 400 tons four years ago.

To keep more water from seeping into the ground and being tainted, more than 90 percent of the site has been paved. A series of drains and underground barriers—including a $325-million* supposedly impermeable “wall” of frozen soil—was also constructed to keep water from flowing into the reactors and the ocean. These have not worked as well as expected, though, especially during typhoons when precipitation spikes, so groundwater continues to be contaminated.

Despite the fact contaminated water was dumped into the sea after the disaster, studies by Japanese and foreign labs have shown radioactive cesium in fish caught in the region has fallen and is now within Japan’s food safety limits. TEPCO will not say when it will decide what to do with all the stored water, because dumping it in the ocean again would invite censure at home and abroad—but there are worries that another powerful quake could cause it to slosh out of the tanks.

Fuel Mop-up

A second major issue at Fukushima is how to handle the fuel¾the melted uranium cores as well as spent and unused fuel rods stored at the reactors. Using robotic probes and 3-D imaging with muons (a type of subatomic particle), workers have found pebbly deposits and debris at various areas inside the primary containment vessels in the three of the plant’s reactor units. These highly radioactive remains are thought to be melted fuel as well as supporting structures. TEPCO has not yet worked out how it can remove the remains, but it wants to start the job in 2021. There are few precedents for the task. Lake Barrett—director of the Three Mile Island nuclear plant during its decommissioning after a partial meltdown at the Middletown, Pa., facility in 1979—says TEPCO will use robots to remotely dig out the melted fuel and store it in canisters on-site before shipping to its final disposal spot. “This is similar to what we did at Three Mile Island, just much larger and with much more sophisticated engineering because their damage is greater than ours was,” Barrett says. “So although the work is technically much more challenging than ours was, Japan has excellent technological capabilities, and worldwide robotic technology has advanced tremendously in the last 30-plus years.”

Shaun Burnie, senior nuclear specialist with Greenpeace Germany, doubts the ambitious cleanup effort can be completed in the time cited, and questions whether the radioactivity can be completely contained. Until TEPCO can verify the conditions of the molten fuel, he says, “there can be no confirmation of what impact and damage the material has had” on the various components of the reactors—and therefore how radiation might leak into the environment in the future.

Although the utility managed to safely remove all 1,533 fuel bundles from the plant’s unit No. 4 reactor by December 2014, it still has to do the same for the hundreds of rods stored at the other three units. This involves clearing rubble, installing shields, dismantling the building roofs, and setting up platforms and special rooftop equipment to remove the rods. Last month a 55-ton dome roof was installed on unit No. 3 to facilitate the safe removal of the 533 fuel bundles that remain in a storage pool there. Whereas removal should begin at No. 3 sometime before April 2019, the fuel at units No. 1 and 2 will not be ready for transfer before 2023, according to TEPCO. And just where all the fuel and other radioactive solid debris on the site will be stored or disposed of long-term has yet to be decided; last month the site’s ninth solid waste storage building, with a capacity of about 61,000 cubic meters, went into operation.

As for what the site itself might look like decades from now, cleanup officials refuse to say. But they are quick to differentiate it from the sarcophagus-style containment of the 1986 Chernobyl catastrophe in the Soviet Union, in what is now Ukraine. Whereas the Chernobyl plant is sealed off and the surrounding area remains off-limits except for brief visits—leaving behind several ghost towns—Japanese officials want as many areas as possible around the Daiichi site to eventually be habitable again.

“To accelerate reconstruction and rebuilding of Fukushima as a region, and the lives of locals, the key is to reduce the mid- and long-term risk,” says Satoru Toyomoto, director for international issues at the Ministry of Economy, Trade and Industry’s Nuclear Accident Response Office. “In that regard, keeping debris on the premises without approval is not an option.” ”

by Tim Hornyak, Scientific American

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Fleeing from Fukushima: a nuclear evacuation reality check — Beyond Nuclear International

” (The following is an excerpt from a longer article on the subject of evacuations after severe nuclear accidents. While this section focuses on Fukushima, there are lessons here for all nuclear sites and the likely failure of “on paper” evacuation plans.)

If another severe nuclear accident, such as Windscale (in 1957), Chernobyl (1986) or Fukushima (2011) were to occur, then the most important response, in terms of preventing future cancer epidemics, is evacuation. The other main responses are shelter and stable iodine prophylaxis. Adverse health effects would primarily depend on wind direction and on the nature of the accident.  This article looks primarily at the Fukushima evacuation and its after-effects.

When the Fukushima-Daiichi, Japan nuclear disaster began on March 11, 2011, evacuations were not immediate and some were hampered by the destructive after-effects of the Tsunami and earthquake that precipitated the nuclear crisis.

Once people were evacuated, little, if any, consideration seems to have been given to how long such evacuations would last. For example, the large majority of the 160,000 people who left or were evacuated from Fukushima Prefecture are still living outside the Prefecture. Many are living in makeshift shelters such as shipping containers or prefabricated houses.

At present, the Japanese Government is attempting to force evacuees (by withdrawing state compensation) to return to less contaminated areas, with little success. Currently, seven years after the accident, an area of about 1,000 square kilometers is still subject to evacuation and no entry orders. This compares with the area of 2,700 square kilometers still evacuated and subject to no or restricted entry at Chernobyl, almost 32 years after the accident.

Experience of the Fukushima Evacuation

In 2015 and 2016, I visited Fukushima Prefecture in Japan with international study teams. These study tours were informative as they revealed information about the evacuations that differed from official accounts by TEPCO and the Japanese Government. From many discussions with local mayors, councillors, local health groups and small community groups, the following information was revealed.

The most common figure cited for evacuees is 160,000, of which 80,000 were evacuated by the authorities and the rest left to evacuate on their own, often on foot, cycles and carts. It took about two weeks to evacuate all parts of the initial 20 km (later 30 km) radius evacuation areas around the Fukushima reactors.

The main reason for the delays was that many roads in the Prefecture were jammed with gridlocks which sometimes lasted 24 hours a day, for several days on end on some roads. These traffic jams were partly due to the poor existing road infrastructure and partly due to many road accidents. These jams were of such severity that safety crews for the Fukushima nuclear station had to be moved in and out mostly by helicopter. All public transport by trains and buses ceased. Mobile telephone networks and the internet crashed due to massive demand.

Thousands of people either refused to leave their homelands or returned later. Older farmers often refused to leave their animals behind or be moved from their ancestral lands. In at least a dozen recorded cases, older farmers slaughtered their cow herds rather than leave them behind (dairy cows need to be milked daily): they then committed suicide themselves in several instances.

According to Hachiya et al (2014), the disaster adversely affected the telecommunications system, water supplies, and electricity supplies including radiation monitoring systems. The local hospital system was dysfunctional; hospitals designated as radiation-emergency facilities were unable to operate because of damage from the earthquake and tsunami, and some were located within designated evacuation zones. Emergency personnel, including fire department personnel, were often asked to leave the area.

At hospitals, evacuations were sometimes carried out hurriedly with the unfortunate result that patients died due to intravenous drips being ripped out, medicaments being left behind, the absence of doctors and nurses who had left, and ambulance road accidents. Many hastily-allocated reception centres (often primary schools) were either unable or ill-equipped to deal with seriously ill patients.

Much confusion resulted when school children were being bussed home, while their parents were trying to reach schools to collect their children. Government officials, doctors, nurses, care workers, police, firepersons, ambulance drivers, emergency crews, teachers, and others faced the dilemma of whether to stay at their posts or return to look after their families. In the event, many emergency crews refused to enter evacuation zones for fear of radiation exposure.

Stable iodine was not issued to most people. Official evacuation plans were either non-existent or inadequate and, in the event, next to useless. In many cases, local mayors took the lead and ordered and supervised evacuations in their villages without waiting for orders or in defiance of them. Apparently, the higher up the administrative level, the greater the levels of indecision and lack of responsibility.

In the years after the accident, the longer-lasting effects of the evacuations have become apparent. These include family separations, marital break-ups, widespread depression, and further suicides. These are discussed in a recent publication (Morimatsu et al, 2017) which relates the sad, often eloquent, stories of the Fukushima people. They differ sharply from the accounts disseminated by TEPCO.

Deaths from evacuations at Fukushima

Official Japanese Government data reveal that nearly 2,000 people died from the effects of evacuations necessary to avoid high radiation exposures from the Fukushima disaster, including from suicides.

The uprooting to unfamiliar areas, cutting of family ties, loss of social support networks, disruption, exhaustion, poor physical conditions and disorientation resulted in many people, in particular older people, apparently losing their will to live.

The evacuations also resulted in increased levels of illnesses among evacuees such as hypertension, diabetes mellitus and dyslipidaemia, psychiatric and mental health problems, polycythaemia — a slow growing blood cancer — cardiovascular disease, liver dysfunction, and severe psychological distress.

Increased suicide rates occurred among younger and older people following the Fukushima evacuations, but the trends are unclear. A 2014 Japanese Cabinet Office report stated that, between March 2011 and July 2014, 56 suicides in Fukushima Prefecture were linked to the nuclear accident.

Should evacuations be ordered?

The above account should not be taken as arguments against evacuations as they constitute an important dose-saving and life-saving strategy during emergencies. Instead, the toll from evacuations should be considered part of the overall toll from nuclear accidents.

In future, deaths from evacuation-related ill-heath and suicides should be included in assessments of the fatality numbers from nuclear disasters.

For example, although about 2,000 deaths occurred during and immediately after the evacuations, it can be calculated from UNSCEAR (2013) collective dose estimates that about 5,000 fatal cancers will arise from the radiation exposures at Fukushima, i.e. taking into account the evacuations. Many more fatal cancers would have occurred if the evacuations had not beeCn carried out.

There is an acute planning dilemma here: if evacuations are carried out (even with good planning) then illnesses and deaths will undoubtedly occur. But if they are not carried out, even more people could die. In such situations, it is necessary to identify the real cause of the problem. And here it is the existence of nuclear power plants near large population centres. In such cases, consideration should be given to the early closure of the nuclear power plants, and switching to safer means of electricity generation.

Conclusions

The experiences of Japanese evacuees after Fukushima are distressing to read. Their experiences were terrible, so much so that it requires Governments of large cities with nearby nuclear power plants to reconsider their own situations and to address the question…. what would happen if radioactive fallout heavily contaminated large areas of their city and required millions of residents to leave for long periods of time, for example several decades?

And how long would evacuations need to continue…. weeks, months, years, or decades? The time length of evacuations is usually avoided in the evacuation plans seen so far. In reality, the answer would depend on cesium-137 concentrations in surface soils. The time period could be decades, as the half-life of the principal radionuclide, Cs-137, is 30 years. This raises the possibility of large cities becoming uninhabited ‘ghost’ towns like Tomioka, Okuma, Namie, Futaba, etc in Japan and Pripyat in Ukraine.

This bleak reality is hard to accept or even comprehend. However it is a matter that some governments need to address after Fukushima. It is unsurprising therefore, that after Fukushima, several major European states including Germany and Switzerland have decided to phase out their nuclear reactors. ”

by Dr. Ian Fairlie, Beyond Nuclear International

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Six years after Fukushima, robots finally find reactors’ melted uranium fuel — The New York Times

” FUKUSHIMA DAIICHI NUCLEAR POWER PLANT, Japan — Four engineers hunched before a bank of monitors, one holding what looked like a game controller. They had spent a month training for what they were about to do: pilot a small robot into the contaminated heart of the ruined Fukushima nuclear plant.

Earlier robots had failed, getting caught on debris or suffering circuit malfunctions from excess radiation. But the newer version, called the Mini-Manbo, or “little sunfish,” was made of radiation-hardened materials with a sensor to help it avoid dangerous hot spots in the plant’s flooded reactor buildings.

The size of a shoe box, the Manbo used tiny propellers to hover and glide through water in a manner similar to an aerial drone.

After three days of carefully navigating through a shattered reactor building, the Manbo finally reached the heavily damaged Unit 3 reactor. There, the robot beamed back video of a gaping hole at the bottom of the reactor and, on the floor beneath it, clumps of what looked like solidified lava: the first images ever taken of the plant’s melted uranium fuel.

The discovery in July at Unit 3, and similar successes this year in locating the fuel of the plant’s other two ruined reactors, mark what Japanese officials hope will prove to be a turning point in the worst atomic disaster since Chernobyl.

The fate of the fuel had been one of the most enduring mysteries of the catastrophe, which occurred on March 11, 2011, when an earthquake and 50-foot tsunami knocked out vital cooling systems here at the plant.

Left to overheat, three of the six reactors melted down. Their uranium fuel rods liquefied like candle wax, dripping to the bottom of the reactor vessels in a molten mass hot enough to burn through the steel walls and even penetrate the concrete floors below.

No one knew for sure exactly how far those molten fuel cores had traveled before desperate plant workers — later celebrated as the “Fukushima Fifty” — were able to cool them again by pumping water into the reactor buildings. With radiation levels so high, the fate of the fuel remained unknown.

As officials became more confident about managing the disaster, they began a search for the missing fuel. Scientists and engineers built radiation-resistant robots like the Manbo and a device like a huge X-ray machine that uses exotic space particles called muons to see the reactors’ innards.

Now that engineers say they have found the fuel, officials of the government and the utility that runs the plant hope to sway public opinion. Six and a half years after the accident spewed radiation over northern Japan, and at one point seemed to endanger Tokyo, the officials hope to persuade a skeptical world that the plant has moved out of post-disaster crisis mode and into something much less threatening: cleanup.

“Until now, we didn’t know exactly where the fuel was, or what it looked like,” said Takahiro Kimoto, a general manager in the nuclear power division of the plant’s operator, Tokyo Electric Power Co., or Tepco. “Now that we have seen it, we can make plans to retrieve it.”

Tepco is keen to portray the plant as one big industrial cleanup site. About 7,000 people work here, building new water storage tanks, moving radioactive debris to a new disposal site, and erecting enormous scaffoldings over reactor buildings torn apart by the huge hydrogen explosions that occurred during the accident.

Access to the plant is easier than it was just a year ago, when visitors still had to change into special protective clothing. These days, workers and visitors can move about all but the most dangerous areas in street clothes.

A Tepco guide explained this was because the central plant grounds had been deforested and paved over, sealing in contaminated soil.

During a recent visit, the mood within the plant was noticeably more relaxed, though movements were still tightly controlled and everyone was required to wear radiation-measuring badges. Inside a “resting building,” workers ate in a large cafeteria and bought snacks in a convenience store.

At the plant’s entrance, a sign warned: “Games like Pokemon GO are forbidden within the facility.”

“We have finished the debris cleanup and gotten the plant under control,” said the guide, Daisuke Hirose, a spokesman for Tepco’s subsidiary in charge of decommissioning the plant. “Now, we are finally preparing for decommissioning.”

In September, the prime minister’s office set a target date of 2021 — the 10th anniversary of the disaster — for the next significant stage, when workers begin extracting the melted fuel from at least one of the three destroyed reactors, though they have yet to choose which one.

The government admits that cleaning up the plant will take at least another three to four decades and tens of billions of dollars. A $100 million research center has been built nearby to help scientists and engineers develop a new generation of robots to enter the reactor buildings and scoop up the melted fuel.

At Chernobyl, the Soviets simply entombed the charred reactor in concrete after the deadly 1986 accident. But Japan has pledged to dismantle the Fukushima plant and decontaminate the surrounding countryside, which was home to about 160,000 people who were evacuated after accident.

Many of them have been allowed to return as the rural towns around the plant have been decontaminated. But without at least starting a cleanup of the plant itself, officials admit they will find it difficult to convince the public that the accident is truly over.

They also hope that beginning the cleanup will help them win the public’s consent to restart Japan’s undamaged nuclear plants, most of which remain shut down since the disaster.

Tepco and the government are treading cautiously to avoid further mishaps that could raise doubts that the plant is under control.

“They are being very methodical — too slow, some would say — in making a careful effort to avoid any missteps or nasty surprises,” said David Lochbaum, director of the nuclear safety project at the Union of Concerned Scientists, who was a co-author of a book on the disaster.

“They want to regain trust. They have learned that trust can be lost much quicker than it can be recovered.”

To show the course followed by the Manbo, Tepco’s Mr. Hirose guided me inside the building containing the undamaged Unit 5 reactor, which is structurally the same as two of the destroyed reactors.

Mr. Hirose pointed toward the spot on a narrow access ramp where two robots, including one that looked like a scorpion, got tangled in February by debris inside the ruined Unit 2.

Before engineers could free the scorpion, its monitoring screen faded to black as its electronic components were overcome by radiation, which Tepco said reached levels of 70 sieverts per hour. (A dose of one sievert is enough to cause radiation sickness in a human.)

Mr. Hirose then led me underneath the reactor, onto what is called the pedestal.

The bottom of the reactor looked like a collection of huge bolts — the access points for control rods used to speed up and slow down the nuclear reaction inside a healthy reactor. The pedestal was just a metal grating, with the building’s concrete floor visible below.

“The overheated fuel would have dropped from here, and melted through the grating around here,” Mr. Hirose said, as we squatted to avoid banging our heads on the reactor bottom. The entire area around the reactor was dark, and cluttered with pipes and machinery.

To avoid getting entangled, the Manbo took three days to travel some 20 feet to the bottom of Unit 3.

To examine the other two reactors, engineers built a “snake” robot that could thread its way through wreckage, and the imaging device using muons, which can pass through most matter. The muon device has produced crude, ghostly images of the reactors’ interiors.

Extracting the melted fuel will present its own set of technical challenges, and risks.

Engineers are developing the new radiation-resistant robots at the Naraha Remote Technology Development Center. It includes a hangar-sized building to hold full-scale mock-ups of the plant and a virtual-reality room that simulates the interiors of the reactor buildings, including locations of known debris.

“I’ve been a robotic engineer for 30 years, and we’ve never faced anything as hard as this,” said Shinji Kawatsuma, director of research and development at the center. “This is a divine mission for Japan’s robot engineers.” “

by Martin Fackler, The New York Times

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Increases in perinatal mortality in prefectures contaminated by the Fukushima nuclear power plant accident in Japan — U.S. National Library of Medicine

This is a spatially stratified longitudinal study.

” Abstract

Descriptive observational studies showed upward jumps in secular European perinatal mortality trends after Chernobyl. The question arises whether the Fukushima nuclear power plant accident entailed similar phenomena in Japan. For 47 prefectures representing 15.2 million births from 2001 to 2014, the Japanese government provides monthly statistics on 69,171 cases of perinatal death of the fetus or the newborn after 22 weeks of pregnancy to 7 days after birth. Employing change-point methodology for detecting alterations in longitudinal data, we analyzed time trends in perinatal mortality in the Japanese prefectures stratified by exposure to estimate and test potential increases in perinatal death proportions after Fukushima possibly associated with the earthquake, the tsunami, or the estimated radiation exposure. Areas with moderate to high levels of radiation were compared with less exposed and unaffected areas, as were highly contaminated areas hit versus untroubled by the earthquake and the tsunami. Ten months after the earthquake and tsunami and the subsequent nuclear accident, perinatal mortality in 6 severely contaminated prefectures jumped up from January 2012 onward: jump odds ratio 1.156; 95% confidence interval (1.061, 1.259), P-value 0.0009. There were slight increases in areas with moderate levels of contamination and no increases in the rest of Japan. In severely contaminated areas, the increases of perinatal mortality 10 months after Fukushima were essentially independent of the numbers of dead and missing due to the earthquake and the tsunami. Perinatal mortality in areas contaminated with radioactive substances started to increase 10 months after the nuclear accident relative to the prevailing and stable secular downward trend. These results are consistent with findings in Europe after Chernobyl. Since observational studies as the one presented here may suggest but cannot prove causality because of unknown and uncontrolled factors or confounders, intensified research in various scientific disciplines is urgently needed to better qualify and quantify the association of natural and artificial environmental radiation with detrimental genetic health effects at the population level. ”

by Hagen Heinrich Scherb, Dr rer nat Dipl-Math, Kuniyoshi Mori, MD, and Keiji Hayashi, MD

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Fukushima Daiichi decay heat and corium status report — SimplyInfo

Read SimplyInfo’s fantastic summary of all of the studies regarding the movement and behavior of the melted corium in Fukushima Daiichi’s reactors 1, 2, and 3 along with an analysis that provides an estimate of where the melted fuel may be located.

by Dean Wilkie, nuclear engineer
edited by Nancy Foust

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