Breaking news from Fukushima!
02-24-2014, 11:10 AM
#41
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Couple in the fact that, especially at that time, the majority of both licensed operators *and* civilian regulators came from a background of nuclear propulsion in the US Navy, and you can see where this mindset comes from.
After the loss of the USS Thresher in 1963, the US Navy implemented a comprehensive overhaul of both design and operational safety procedures known as the SUBSAFE project. This, in complement with the fanatical devotion to safety and good design projected by Adm. Hyman Rickover (the so-called father of the nuclear navy) upon all those who served under him, have contributed to the essentially perfect operation record of US Naval nuclear propulsion, with not a single radiological accident in 65 years of naval nuclear propulsion.
In the aftermath of TMI, a similar overhaul of design and operational procedures in the US was undertaken. Rectors were retrofitted with better and more comprehensive fault-tolerant backups (defense-in-depth), safety systems were greatly improved, procedures and training were radically overhauled.
And, of course, its important to understand that despite all the hubbub, "the system" did actually work at TMI. Despite the meltdown, there was no release of core material into the environment, and the net impact on both public health and environmental safety was, by all reasonable accounts, zero.
I'm not reading this thread really, but if you guys are interested, my wife's coworkers wrote a pretty detailed book on the disaster at Fukushima.
Amazon.com: Fukushima: The Story of a Nuclear Disaster eBook: David Lochbaum, Edwin Lyman, Susan Q. Stranahan: Kindle Store
Amazon.com: Fukushima: The Story of a Nuclear Disaster eBook: David Lochbaum, Edwin Lyman, Susan Q. Stranahan: Kindle Store
The one problem with using Fukushima as an object lesson, which distances it from nuclear accidents such as Windscale, SL-1, TMI and Chernobyl, is that it was such a bizarre and unforeseeable occurrence. Yes, there are certainly elements of the plant design which, in retrospect, could have been improved. But unlike the chain of events which led to the aforementioned, the geologic events which precipitated the failure at Fukushima was such a once-in-a-century boundary event that it pretty much falls into the category of acceptable losses, in much the same way as deaths due to building collapse during the 1906 San Francisco earthquake or Hurricane Camille in 1969.
If we insist that every single thing which man creates be absolutely safe, then we will never be able to build single thing. We can, at best, have a sense of perspective. That means looking at Fuku through the lens which shows us that, even by the most pessimistic assessment, the deadliest reactor accident in the whole of human history in a modern, western-style design, harmed only a minute fraction of the people who were killed or injured more directly by the unprecedented natural disaster which caused the meltdown in the first place.
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04-07-2015, 12:34 PM
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Fukushima radiation has reached North American shores
Seaborne radiation from Japan's Fukushima nuclear disaster has reached North America.
Scientists at the Woods Hole Oceanographic Institution detected small amounts of cesium-134 and cesium-137 in a sample of seawater taken in February from a dock on Vancouver Island, British Columbia.
It's the first time radioactivity from the March 2011 triple meltdown has been identified on West Coast shores.
Woods Hole chemical oceanographer Ken Buesseler emphasized that the radiation is at very low levels that aren't expected to harm human health or the environment.
Scientists at the Woods Hole Oceanographic Institution detected small amounts of cesium-134 and cesium-137 in a sample of seawater taken in February from a dock on Vancouver Island, British Columbia.
It's the first time radioactivity from the March 2011 triple meltdown has been identified on West Coast shores.
Woods Hole chemical oceanographer Ken Buesseler emphasized that the radiation is at very low levels that aren't expected to harm human health or the environment.
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05-02-2015, 11:34 AM
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I thought we had a "JoeP Nuclear thread" other than this one, but i can't find it.
Regulators OK Fermi 3, but DTE has no plans to build it
******* hell...
Alliance to Halt Fermi 3 | Fermi 3 is a gamble we cannot afford.
Click to read more.
I'd love to some day work at the Fermi plant.
Regulators OK Fermi 3, but DTE has no plans to build it
Federal regulators have approved construction of the Fermi 3 nuclear reactor near Monroe, although it may not ever get built.
...
Fermi 3 would be an Economic Simplified Boiling-Water Reactor built by GE-Hitachi. Its design is considered a third-generation reactor with passive safety features that enable it to cool itself for a week in cases of complete power loss, such as occurred in the 2011 Fukushima facility in Japan.
...
Fermi 3 would be an Economic Simplified Boiling-Water Reactor built by GE-Hitachi. Its design is considered a third-generation reactor with passive safety features that enable it to cool itself for a week in cases of complete power loss, such as occurred in the 2011 Fukushima facility in Japan.
Alliance to Halt Fermi 3 | Fermi 3 is a gamble we cannot afford.
Click to read more.
On Sunday, April 19, 2015, we ran a booth at Veg Fest in Novi. We found out that a lot of people didn’t even know that DTE Energy is planning on building a new nuclear reactor in Michigan – but now they do. Of the more than 100 people who stopped by the booth, only two were in favor of the idea. If we can manage to reach enough people with the information, we can stop DTE’s dangerous, expensive and unneeded project.
I'd love to some day work at the Fermi plant.
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05-20-2015, 10:49 AM
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Fukushima nuclear plant ordered to upgrade from Windows XP- The Inquirer
Tokyo Electric Power Company (Tepco) has had its wrists slapped by the Board of Audit of Japan, an organisation that oversees the finances of Japan's government and its agencies, after it discovered that about 48,000 of Tepco's PCs were running XP. This is an outdated version of Windows that no longer receives security updates or technical support from Microsoft.
A report in The Japan Times said that Tepco figured it could save some dosh by delaying an upgrade from XP while it faces a multi-billion dollar clean-up and compensation bill from the 2011 crisis.
"The company decided, on its own initiative, to move up the deadline to update the software due to system security concerns," a Tepco spokesman said.
The Board of Audit warned Tepco in an audit undertaken in March, which can be found here in Japanese, not to be so stingy and to put the upgrade at the top of its to-do list to lower the risk of another nuclear disaster as a result of poor cyber security.
"Upgrading the operating system must be done as swiftly as possible, and the firm must not push it back, given the security risks," said the board.
Technical support for XP ended just over a year ago, but that doesn't mean people have stopped using it.
The latest monthly figures from Netmarketshare show that XP has a market share of 16.94 percent.
A report in The Japan Times said that Tepco figured it could save some dosh by delaying an upgrade from XP while it faces a multi-billion dollar clean-up and compensation bill from the 2011 crisis.
"The company decided, on its own initiative, to move up the deadline to update the software due to system security concerns," a Tepco spokesman said.
The Board of Audit warned Tepco in an audit undertaken in March, which can be found here in Japanese, not to be so stingy and to put the upgrade at the top of its to-do list to lower the risk of another nuclear disaster as a result of poor cyber security.
"Upgrading the operating system must be done as swiftly as possible, and the firm must not push it back, given the security risks," said the board.
Technical support for XP ended just over a year ago, but that doesn't mean people have stopped using it.
The latest monthly figures from Netmarketshare show that XP has a market share of 16.94 percent.
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09-30-2015, 09:04 PM
#46
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Came across a very interesting and informative article recently. It's from The Times, which is not generally a bastion of conservative objectivity, so that should tell you something. This should be required reading for anti-nuclear activists.
When Radiation Isn’t the Real Risk
SEPT. 21, 2015
Evacuated patients at a hospital near the Fukushima power plant after the nuclear accident in 2011. No one has been killed or sickened by the radiation, according to the International Atomic Energy Agency. But about 1,600 died of causes related to the evacuation.
This spring, four years after the nuclear accident at Fukushima, a small group of scientists met in Tokyo to evaluate the deadly aftermath.
No one has been killed or sickened by the radiation — a point confirmed last month by the International Atomic Energy Agency. Even among Fukushima workers, the number of additional cancer cases in coming years is expected to be so low as to be undetectable, a blip impossible to discern against the statistical background noise.
But about 1,600 people died from the stress of the evacuation — one that some scientists believe was not justified by the relatively moderate radiation levels at the Japanese nuclear plant.
Epidemiologists speak of “stochastic deaths,” those they predict will happen in the future because of radiation or some other risk. With no names attached to the numbers, they remain an abstraction.
But these other deaths were immediate and unequivocally real.
“The government basically panicked,” said Dr. Mohan Doss, a medical physicist who spoke at the Tokyo meeting, when I called him at his office at Fox Chase Cancer Center in Philadelphia. “When you evacuate a hospital intensive care unit, you cannot take patients to a high school and expect them to survive.”
Among other victims were residents of nursing homes. And there were the suicides. “It was the fear of radiation that ended up killing people,” he said.
Most of the fallout was swept out to sea by easterly winds, and the rest was dispersed and diluted over the land. Had the evacuees stayed home, their cumulative exposure over four years, in the most intensely radioactive locations, would have been about 70 millisieverts — roughly comparable to receiving a high-resolution whole-body diagnostic scan each year. But those hot spots were anomalies.
By Dr. Doss’s calculations, most residents would have received much less, about 4 millisieverts a year. The average annual exposure from the natural background radiation of the earth is 2.4 millisieverts.
How the added effect of the fallout would have compared with that of the evacuation depends on the validity of the “linear no-threshold model,” which assumes that any amount of radiation, no matter how small, causes some harm.
Dr. Doss is among scientists who question that supposition, one built into the world’s radiation standards. Below a certain threshold, they argue, low doses are harmless and possibly even beneficial — a long-debated phenomenon called radiation hormesis.
Recently he and two other researchers, Carol S. Marcus of Harbor-U.C.L.A. Medical Center in Los Angeles and Mark L. Miller of Sandia National Laboratories in Albuquerque, petitioned the Nuclear Regulatory Commission to revise its rules to avoid overreactions to what may be nonexistent threats.
The period for public comments is still open, and when it is over, there will be a mass of conflicting evidence to puzzle through.
A full sievert of radiation is believed to eventually cause fatal cancers in about 5 percent of the people exposed. Under the linear no-threshold model, a millisievert would impose one-one thousandth of the risk: 0.005 percent, or five deadly cancers in a population of 100,000.
About twice that many people were evacuated from a 20-kilometer area near the Fukushima reactors. By avoiding what would have been an average cumulative exposure of 16 millisieverts, the number of cancer deaths prevented was perhaps 160, or 10 percent of the total who died in the evacuation itself.
But that estimate assumes the validity of the current standards. If low levels of radiation are less harmful, then the fallout might not have caused any increase in the cancer rate.
The idea of hormesis goes further, proposing that weak radiation can actually reduce a person’s risk. Life evolved in a mildly radioactive environment, and some laboratory experiments and animal studies indicate that low exposures unleash protective antioxidants and stimulate the immune system, conceivably protecting against cancers of all kinds.
Epidemiological studies of survivors of Hiroshima and Nagasaki have been interpreted both ways — as demonstrating and refuting hormesis. But because radiation regulations assume there is no safe level, clinical trials testing low-dose therapy have been impossible to conduct.
One experiment, however, occurred inadvertently three decades ago in Taiwan after about 200 buildings housing 10,000 people were constructed from steel contaminated with radioactive cobalt. Over the years, residents were exposed to an average dose of about 10.5 millisieverts a year, more than double the estimated average for Fukushima.
Yet a study in 2006 found fewer cancer cases compared with the general public: 95, when 115 were expected.
Neither the abstract of the paper nor of a second one published two years later mention the overall decrease. (The authors speculated that the apartment dwellers may have been healthier than the population at large.) The focus instead was on weaker results suggesting a few excess leukemia and breast cancer cases — and on a parsing of the data showing an overall increased cancer risk for residents exposed before age 30.
More recently, a study of radon by a Johns Hopkins scientist suggested that people living with higher concentrations of the radioactive gas had correspondingly lower rates of lung cancer. If so, then homeowners investing in radon mitigation to meet federal safety standards may be slightly increasing their cancer risk. These and similar findings have also been disputed.
All research like this is bedeviled by “confounders” — differences between populations that must be accounted for. Some are fairly easy (older people and smokers naturally get more cancer), but there is always some statistical wiggle room. As with so many issues, what should be a scientific argument becomes rhetorical, with opposing interest groups looking at the data with just the right squint to resolve it according to their needs.
There is more here at stake than agonizing over irreversible acts, like the evacuation of Fukushima. Fear of radiation, even when diluted to homeopathic portions, compels people to forgo lifesaving diagnostic tests and radiotherapies.
We’re bad at balancing risks, we humans, and we live in a world of continual uncertainty. Trying to avoid the horrors we imagine, we risk creating ones that are real.
http://www.nytimes.com/2015/09/22/sc...risk.html?_r=0
When Radiation Isn’t the Real Risk
SEPT. 21, 2015
Evacuated patients at a hospital near the Fukushima power plant after the nuclear accident in 2011. No one has been killed or sickened by the radiation, according to the International Atomic Energy Agency. But about 1,600 died of causes related to the evacuation.
This spring, four years after the nuclear accident at Fukushima, a small group of scientists met in Tokyo to evaluate the deadly aftermath.
No one has been killed or sickened by the radiation — a point confirmed last month by the International Atomic Energy Agency. Even among Fukushima workers, the number of additional cancer cases in coming years is expected to be so low as to be undetectable, a blip impossible to discern against the statistical background noise.
But about 1,600 people died from the stress of the evacuation — one that some scientists believe was not justified by the relatively moderate radiation levels at the Japanese nuclear plant.
Epidemiologists speak of “stochastic deaths,” those they predict will happen in the future because of radiation or some other risk. With no names attached to the numbers, they remain an abstraction.
But these other deaths were immediate and unequivocally real.
“The government basically panicked,” said Dr. Mohan Doss, a medical physicist who spoke at the Tokyo meeting, when I called him at his office at Fox Chase Cancer Center in Philadelphia. “When you evacuate a hospital intensive care unit, you cannot take patients to a high school and expect them to survive.”
Among other victims were residents of nursing homes. And there were the suicides. “It was the fear of radiation that ended up killing people,” he said.
Most of the fallout was swept out to sea by easterly winds, and the rest was dispersed and diluted over the land. Had the evacuees stayed home, their cumulative exposure over four years, in the most intensely radioactive locations, would have been about 70 millisieverts — roughly comparable to receiving a high-resolution whole-body diagnostic scan each year. But those hot spots were anomalies.
By Dr. Doss’s calculations, most residents would have received much less, about 4 millisieverts a year. The average annual exposure from the natural background radiation of the earth is 2.4 millisieverts.
How the added effect of the fallout would have compared with that of the evacuation depends on the validity of the “linear no-threshold model,” which assumes that any amount of radiation, no matter how small, causes some harm.
Dr. Doss is among scientists who question that supposition, one built into the world’s radiation standards. Below a certain threshold, they argue, low doses are harmless and possibly even beneficial — a long-debated phenomenon called radiation hormesis.
Recently he and two other researchers, Carol S. Marcus of Harbor-U.C.L.A. Medical Center in Los Angeles and Mark L. Miller of Sandia National Laboratories in Albuquerque, petitioned the Nuclear Regulatory Commission to revise its rules to avoid overreactions to what may be nonexistent threats.
The period for public comments is still open, and when it is over, there will be a mass of conflicting evidence to puzzle through.
A full sievert of radiation is believed to eventually cause fatal cancers in about 5 percent of the people exposed. Under the linear no-threshold model, a millisievert would impose one-one thousandth of the risk: 0.005 percent, or five deadly cancers in a population of 100,000.
About twice that many people were evacuated from a 20-kilometer area near the Fukushima reactors. By avoiding what would have been an average cumulative exposure of 16 millisieverts, the number of cancer deaths prevented was perhaps 160, or 10 percent of the total who died in the evacuation itself.
But that estimate assumes the validity of the current standards. If low levels of radiation are less harmful, then the fallout might not have caused any increase in the cancer rate.
The idea of hormesis goes further, proposing that weak radiation can actually reduce a person’s risk. Life evolved in a mildly radioactive environment, and some laboratory experiments and animal studies indicate that low exposures unleash protective antioxidants and stimulate the immune system, conceivably protecting against cancers of all kinds.
Epidemiological studies of survivors of Hiroshima and Nagasaki have been interpreted both ways — as demonstrating and refuting hormesis. But because radiation regulations assume there is no safe level, clinical trials testing low-dose therapy have been impossible to conduct.
One experiment, however, occurred inadvertently three decades ago in Taiwan after about 200 buildings housing 10,000 people were constructed from steel contaminated with radioactive cobalt. Over the years, residents were exposed to an average dose of about 10.5 millisieverts a year, more than double the estimated average for Fukushima.
Yet a study in 2006 found fewer cancer cases compared with the general public: 95, when 115 were expected.
Neither the abstract of the paper nor of a second one published two years later mention the overall decrease. (The authors speculated that the apartment dwellers may have been healthier than the population at large.) The focus instead was on weaker results suggesting a few excess leukemia and breast cancer cases — and on a parsing of the data showing an overall increased cancer risk for residents exposed before age 30.
More recently, a study of radon by a Johns Hopkins scientist suggested that people living with higher concentrations of the radioactive gas had correspondingly lower rates of lung cancer. If so, then homeowners investing in radon mitigation to meet federal safety standards may be slightly increasing their cancer risk. These and similar findings have also been disputed.
All research like this is bedeviled by “confounders” — differences between populations that must be accounted for. Some are fairly easy (older people and smokers naturally get more cancer), but there is always some statistical wiggle room. As with so many issues, what should be a scientific argument becomes rhetorical, with opposing interest groups looking at the data with just the right squint to resolve it according to their needs.
There is more here at stake than agonizing over irreversible acts, like the evacuation of Fukushima. Fear of radiation, even when diluted to homeopathic portions, compels people to forgo lifesaving diagnostic tests and radiotherapies.
We’re bad at balancing risks, we humans, and we live in a world of continual uncertainty. Trying to avoid the horrors we imagine, we risk creating ones that are real.
http://www.nytimes.com/2015/09/22/sc...risk.html?_r=0
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02-15-2016, 10:59 PM
#47
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Objective commentary:
How is Fukushima’s cleanup going five years after its meltdown? Not so well.
By Anna Fifield February 10
A journalist wearing protective gear looks at the No. 3 reactor building at Tokyo Electric Power Co.'s tsunami-crippled Fukushima Daiichi nuclear power plant in northeastern Japan on Wednesday. (Toru Hanai/Reuters)
FUTABA, Japan — Seen from the road below, the Fukushima Daiichi nuclear power station looks much as it may have right after the catastrophic earthquake and tsunami that caused a triple meltdown here almost five years ago.
The No. 3 reactor building, which exploded in a hydrogen fireball during the disaster, remains a tangle of broken concrete and twisted metal. A smashed crane sits exactly where it was on March 11, 2011. To the side of the reactor units, a building that once housed boilers stands open to the shore, its rusted, warped tanks exposed.
The scene is a testament to the chaos that was unleashed when the tsunami engulfed these buildings, triggering the world’s worst nuclear disaster since the one at Chernobyl, in Ukraine, in 1986. Almost 16,000 people were killed along Japan’s northeastern coast in the tsunami, and 160,000 more lost their homes and livelihoods.
Tokyo Electric Power Co. (Tepco), the utility company that runs the Fukushima plant and drew fierce criticism for its handling of the disaster, says the situation has improved greatly.
A worker leaves a room with shelves lined with helmets at the plant. The Tepco utility still faces enormous challenges in connection with the disposal of contaminated water, soil and nuclear fuel debris. (Toru Hanai/Reuters)
“In the last five years, radiation levels have been reduced substantially, and we can say that the plant is stable now,” said Akira Ono, the Tepco plant superintendent.
Efforts to contain the contamination have progressed, according to Tepco, including the completion Tuesday of a subterranean “ice wall” around the plant that, once operational, is meant to freeze the ground and stop leakage. Moves to decommission the plant — a process that could take 30 or 40 years, Ono estimated — are getting underway.
People will be allowed to return to their homes in the nearby town of Naraha next month and to Tomioka, even closer to the plant, next year. For now, Tomioka and neighboring Okuma remain ghost towns, lined with convenience stores, fast-food restaurants and gambling parlors that haven’t had a customer in five years. Bicycles lean near front doors, and flowerpots sit empty on windowsills.
A sign on the road to the plant showed a radiation reading of 3.37 microsieverts per hour, at the upper end of safe. At a viewing spot overlooking the reactor buildings, it shot past 200, a level at which prolonged exposure could be dangerous. Both readings are hundreds of times lower than they were a couple of years ago.
After about 20 minutes at the viewing spot, a Tepco official bustled visiting reporters, wearing protective suits, onto a bus. “We don’t want you out here too long,” he said. Below, men continued working on the site.
But one huge question remains: What is to be done with all the radioactive material?
A worker is seen from a bus carrying members of the media near the No. 3 reactor building at the plant on Wednesday. (Toru Hanai/Reuters)
There’s the groundwater that is flowing into the reactor buildings, where it becomes contaminated. It has been treated — Tepco says it can remove 62 nuclides from the water, including strontium, which can burrow into bones and irradiate tissue. It cannot filter out tritium, a radioactive isotope of hydrogen that can be used to make nuclear bombs but is not considered especially harmful to humans.
The water initially was stored in huge bolted tanks in the aftermath of the disaster, but the tanks have leaked highly contaminated radioactive water into the sea on an alarming number of occasions.
Now Tepco is building more-secure welded tanks to hold the water, theoretically for up to 20 years. There are now about 1,000 tanks holding 750,000 tons of contaminated water, with space for 100,000 tons more. The company says it hopes to increase capacity to 950,000 tons within a year or two, as well as halve the amount of water that needs to be stored from the current 300 tons per day.
As part of those efforts, Tepco built the 1,500-yard-long ice wall around the four reactor buildings to freeze the soil and keep groundwater from getting in and becoming radioactive. Company officials hoped to have the wall working next month; on Wednesday, however, Japan’s nuclear watchdog blocked the plan, saying the risk of leakage was still too high.
The options for getting rid of the contaminated water include trying to remove the tritium from it before letting it run into the sea; evaporating it, as was done at Three Mile Island, the Pennsylvania plant that melted down in 1979; and injecting it deep into the ground, using technology similar to that used to extract shale gas. A government task force is considering which option to choose.
“These all have different advantages and disadvantages; they have different costs and different social acceptance,” said Seiichi Suzuki, manager of tank construction at the plant.
Then there’s the radioactive soil that has been collected from areas around the Fukushima Daiichi plant during cleanup efforts. More than 700 million cubic feet of soil — enough to fill 8,000 Olympic-size swimming pools — has been packed into large black plastic bags and is being stored, row upon row, in local fields.
More than 700 of the bags, which contain radioactive cesium isotopes, were swept away during floods last year, some ending up in rivers 100 miles away. The government has said that 99.8 percent of the soil can be recycled.
Finally, and most problematically, there’s the nuclear fuel from the plant itself.
The fuel that melted down remains in containment vessels in its reactors, and this part of the plant is so dangerous to humans that robots are used to work there. Getting to this fuel and removing it safely is a task that will take decades.
Asked about the decommissioning process, Tepco’s Ono said the work was about 10 percent done.
“The biggest challenge is going to be the removal of the nuclear fuel debris,” he said. “We don’t even know what state the debris is in at the moment.”
Japan does not have a nuclear waste dump, and there is vehement resistance to disposing of contaminated material on land.
As a result, one of the options the government is considering is building a nuclear waste dump under the seabed, about eight miles off the Fukushima coast. It would be connected to the land by a tunnel so it would not contravene international regulations on disposing of nuclear waste into the sea. A government study group is set to report on that proposal by the end of the summer.
Many groups, from fishermen to anti-nuclear activists, staunchly oppose the idea of burying the radioactive material at sea in such a seismically active area.
“At some point it would leak and affect the environment,” said Hideyuki Ban, co-director of the Citizens’ Nuclear Information Center. “Some say it’ll be fine, as it will be diluted in the ocean, but it’s unclear whether it will be diluted well. If it gets into fish, it could end up on someone’s table.”
Aileen Mioko Smith, executive director of Green Action, a Kyoto-based anti-nuclear group, agreed.
“The seabed is just like land. It’s not flat, but has mountains and valleys,” she said. “Japan sits on multiple tectonic plates and is earthquake-prone. It’s too easy to think, ‘If not on land, how about the seabed?’ ”
https://www.washingtonpost.com/world...b19_story.html
How is Fukushima’s cleanup going five years after its meltdown? Not so well.
By Anna Fifield February 10
A journalist wearing protective gear looks at the No. 3 reactor building at Tokyo Electric Power Co.'s tsunami-crippled Fukushima Daiichi nuclear power plant in northeastern Japan on Wednesday. (Toru Hanai/Reuters)
FUTABA, Japan — Seen from the road below, the Fukushima Daiichi nuclear power station looks much as it may have right after the catastrophic earthquake and tsunami that caused a triple meltdown here almost five years ago.
The No. 3 reactor building, which exploded in a hydrogen fireball during the disaster, remains a tangle of broken concrete and twisted metal. A smashed crane sits exactly where it was on March 11, 2011. To the side of the reactor units, a building that once housed boilers stands open to the shore, its rusted, warped tanks exposed.
The scene is a testament to the chaos that was unleashed when the tsunami engulfed these buildings, triggering the world’s worst nuclear disaster since the one at Chernobyl, in Ukraine, in 1986. Almost 16,000 people were killed along Japan’s northeastern coast in the tsunami, and 160,000 more lost their homes and livelihoods.
Tokyo Electric Power Co. (Tepco), the utility company that runs the Fukushima plant and drew fierce criticism for its handling of the disaster, says the situation has improved greatly.
A worker leaves a room with shelves lined with helmets at the plant. The Tepco utility still faces enormous challenges in connection with the disposal of contaminated water, soil and nuclear fuel debris. (Toru Hanai/Reuters)
“In the last five years, radiation levels have been reduced substantially, and we can say that the plant is stable now,” said Akira Ono, the Tepco plant superintendent.
Efforts to contain the contamination have progressed, according to Tepco, including the completion Tuesday of a subterranean “ice wall” around the plant that, once operational, is meant to freeze the ground and stop leakage. Moves to decommission the plant — a process that could take 30 or 40 years, Ono estimated — are getting underway.
People will be allowed to return to their homes in the nearby town of Naraha next month and to Tomioka, even closer to the plant, next year. For now, Tomioka and neighboring Okuma remain ghost towns, lined with convenience stores, fast-food restaurants and gambling parlors that haven’t had a customer in five years. Bicycles lean near front doors, and flowerpots sit empty on windowsills.
A sign on the road to the plant showed a radiation reading of 3.37 microsieverts per hour, at the upper end of safe. At a viewing spot overlooking the reactor buildings, it shot past 200, a level at which prolonged exposure could be dangerous. Both readings are hundreds of times lower than they were a couple of years ago.
After about 20 minutes at the viewing spot, a Tepco official bustled visiting reporters, wearing protective suits, onto a bus. “We don’t want you out here too long,” he said. Below, men continued working on the site.
But one huge question remains: What is to be done with all the radioactive material?
A worker is seen from a bus carrying members of the media near the No. 3 reactor building at the plant on Wednesday. (Toru Hanai/Reuters)
There’s the groundwater that is flowing into the reactor buildings, where it becomes contaminated. It has been treated — Tepco says it can remove 62 nuclides from the water, including strontium, which can burrow into bones and irradiate tissue. It cannot filter out tritium, a radioactive isotope of hydrogen that can be used to make nuclear bombs but is not considered especially harmful to humans.
The water initially was stored in huge bolted tanks in the aftermath of the disaster, but the tanks have leaked highly contaminated radioactive water into the sea on an alarming number of occasions.
Now Tepco is building more-secure welded tanks to hold the water, theoretically for up to 20 years. There are now about 1,000 tanks holding 750,000 tons of contaminated water, with space for 100,000 tons more. The company says it hopes to increase capacity to 950,000 tons within a year or two, as well as halve the amount of water that needs to be stored from the current 300 tons per day.
As part of those efforts, Tepco built the 1,500-yard-long ice wall around the four reactor buildings to freeze the soil and keep groundwater from getting in and becoming radioactive. Company officials hoped to have the wall working next month; on Wednesday, however, Japan’s nuclear watchdog blocked the plan, saying the risk of leakage was still too high.
The options for getting rid of the contaminated water include trying to remove the tritium from it before letting it run into the sea; evaporating it, as was done at Three Mile Island, the Pennsylvania plant that melted down in 1979; and injecting it deep into the ground, using technology similar to that used to extract shale gas. A government task force is considering which option to choose.
“These all have different advantages and disadvantages; they have different costs and different social acceptance,” said Seiichi Suzuki, manager of tank construction at the plant.
Then there’s the radioactive soil that has been collected from areas around the Fukushima Daiichi plant during cleanup efforts. More than 700 million cubic feet of soil — enough to fill 8,000 Olympic-size swimming pools — has been packed into large black plastic bags and is being stored, row upon row, in local fields.
More than 700 of the bags, which contain radioactive cesium isotopes, were swept away during floods last year, some ending up in rivers 100 miles away. The government has said that 99.8 percent of the soil can be recycled.
Finally, and most problematically, there’s the nuclear fuel from the plant itself.
The fuel that melted down remains in containment vessels in its reactors, and this part of the plant is so dangerous to humans that robots are used to work there. Getting to this fuel and removing it safely is a task that will take decades.
Asked about the decommissioning process, Tepco’s Ono said the work was about 10 percent done.
“The biggest challenge is going to be the removal of the nuclear fuel debris,” he said. “We don’t even know what state the debris is in at the moment.”
Japan does not have a nuclear waste dump, and there is vehement resistance to disposing of contaminated material on land.
As a result, one of the options the government is considering is building a nuclear waste dump under the seabed, about eight miles off the Fukushima coast. It would be connected to the land by a tunnel so it would not contravene international regulations on disposing of nuclear waste into the sea. A government study group is set to report on that proposal by the end of the summer.
Many groups, from fishermen to anti-nuclear activists, staunchly oppose the idea of burying the radioactive material at sea in such a seismically active area.
“At some point it would leak and affect the environment,” said Hideyuki Ban, co-director of the Citizens’ Nuclear Information Center. “Some say it’ll be fine, as it will be diluted in the ocean, but it’s unclear whether it will be diluted well. If it gets into fish, it could end up on someone’s table.”
Aileen Mioko Smith, executive director of Green Action, a Kyoto-based anti-nuclear group, agreed.
“The seabed is just like land. It’s not flat, but has mountains and valleys,” she said. “Japan sits on multiple tectonic plates and is earthquake-prone. It’s too easy to think, ‘If not on land, how about the seabed?’ ”
https://www.washingtonpost.com/world...b19_story.html
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03-06-2016, 11:10 AM
#48
Fukushima: Tokyo was on the brink of nuclear catastrophe, admits former prime minister - Telegraph
Japan's prime minister at the time of the 2011 earthquake and tsunami has revealed that the country came within a “paper-thin margin” of a nuclear disaster requiring the evacuation of 50 million people.
In an interview with The Telegraph to mark the fifth anniversary of the tragedy, Naoto Kan described the panic and disarray at the highest levels of the Japanese government as it fought to control multiple meltdowns at the crippled Fukushima Daiichi nuclear power station.
He said he considered evacuating the capital, Tokyo, along with all other areas within 160 miles of the plant, and declaring martial law. “The future existence of Japan as a whole was at stake,” he said. “Something on that scale, an evacuation of 50 million, it would have been like a losing a huge war.”
Mr Kan admitted he was frightened and said he got “no clear information” out of Tepco, the plant’s operator. He was “very shocked” by the performance of Nobuaki Terasaka, his own government’s key nuclear safety adviser. “We questioned him and he was unable to give clear responses,” he said.
“We asked him – do you know anything about nuclear issues? And he said no, I majored in economics.”
In an interview with The Telegraph to mark the fifth anniversary of the tragedy, Naoto Kan described the panic and disarray at the highest levels of the Japanese government as it fought to control multiple meltdowns at the crippled Fukushima Daiichi nuclear power station.
He said he considered evacuating the capital, Tokyo, along with all other areas within 160 miles of the plant, and declaring martial law. “The future existence of Japan as a whole was at stake,” he said. “Something on that scale, an evacuation of 50 million, it would have been like a losing a huge war.”
Mr Kan admitted he was frightened and said he got “no clear information” out of Tepco, the plant’s operator. He was “very shocked” by the performance of Nobuaki Terasaka, his own government’s key nuclear safety adviser. “We questioned him and he was unable to give clear responses,” he said.
“We asked him – do you know anything about nuclear issues? And he said no, I majored in economics.”
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