Tag Archives: Fukushima nuclear disaster

The Burial: nuclear waste of Fukushima

piles of radioactive waste from Fukushima, image from japan times.

The Japanese government on November 17, 2017 began the disposal of low-level radioactive waste generated by the 2011 Fukushima nuclear disaster, more than six years after the crisis triggered by the devastating earthquake and tsunami.

A disposal site in Fukushima Prefecture accepted the first shipment of the waste, which contains radioactive cesium exceeding 8,000 becquerels and up to 100,000 becquerels per kilogram, and includes rice straw, sludge and ash from waste incineration.

The Environment Ministry is in charge of the disposal of the waste, amounting to about 200,000 tons in 11 prefectures across the country as of the end of September 2017, Most of the waste, 170,000 tons, is in the prefecture hosting the crippled Fukushima Daiichi nuclear power plant.

Under the ministry’s policy, the waste is to be disposed of in each prefecture. However, Fukushima is the only prefecture where its disposal has started, while the other prefectures have met with opposition from local residents. In Fukushima, it will take six years to finish bringing the waste that has been stored in the prefecture into the disposal site, the ministry said.

Excerpt from NationalDisposal of low-level radioactive waste from Fukushima nuclear disaster begins, Japan Times, Nov. 18, 2017

How to Flirt with Disaster and Pay: the class actions of Fukushima refugees

image with wikipedia

Negligence by the Japanese government and Tokyo Electric Power Co. caused the triple meltdowns at the Fukushima Daiichi nuclear power plant, a court ruled on October 10, 2017 in the biggest class-action suit related to the March 2011 accident.

The Fukushima District Court ordered the government and Tepco to pay a total of Yen 498 million ($4.4 million) plus delinquency charges to 2,907 people who fled the radiation that was released into the air and water after a tsunami flooded the power plant, knocking out the power to the vital cooling system. It was the second time a court found the government responsible for failing to prepare adequately for the likelihood of a large tsunami wave hitting the plant.

If Japan’s government had ordered Tepco to make sure the plant was ready to withstand a tsunami wave of 15.7 meters (51.5 feet), Tepco would have made sure critical instruments were waterproof, Tuesday’s ruling said.”The accident, triggered by total loss of power, could have been avoided, ” Judge Hideki Kanazawa said.

The compensation represents a small fraction of the damages the residents had sought. They also wanted compensation for every month that radiation levels stay above normal, but the court rejected that claim. Still, with some 30 class-action lawsuits so far brought by more than 10,000 affected residents. The October 11, 2017 ruling is a sign additional compensation costs could weigh on both the government and Tepco for years to come.  Tepco has so far paid more than Yen7.6 trillion ($67 billion) in compensation to residents affected by the accident, and has been struggling to clean up the reactors — a daunting technological task that could take decades.

As of September 2017, nearly 55,000 Fukushima residents are registered as evacuees, meaning they can’t return home and haven’t settled permanently elsewhere.

The plaintiffs argued the government and Tepco failed to give adequate attention to studies that said a major tsunami could occur in the area of the plant. One 2002 study by the government’s Earthquake Research Promotion Unit said there was a 20% chance of a magnitude 8 tsunami-triggering earthquake in the area off Fukushima within 30 years. Another study by Tepco’s senior safety engineer in 2007 found there was about a 10% chance that a tsunami could breach Fukushima Daiichi’s defenses within 50 years.

The defendants said the scientific basis for such predictions was unclear, and even if the calculations were correct, the chance was too low to require immediate steps in response. The government said it wasn’t until after the accident that it gained the ability to force Tepco to take anti-flooding measures. Both argued the compensation already being paid to displaced people was adequate.

On March 11, 2011, a tsunami triggered by an earthquake flooded the Fukushima Daiichi plant, knocking out auxiliary power sources that were supposed to keep the reactors’ cooling systems running. Three reactors melted down.

Excerpts from Redress Ordered In Fukushima Case, Wall Street Journal, Oct. 11, 2017

Robots to the Rescue: Fukushima Japan

jorange on equipment probably melted nuclear fuel

A robot operating deep inside a failed reactor at the stricken Fukushima nuclear plant north of Tokyo has revealed what appears to be stalactites of melted nuclear fuel, the plant’s operator has said.
The discovery is considered a key development in the decommissioning process of the plant, which suffered a catastrophic meltdown in 2011 after a huge tsunami swamped the facility.
Operating remotely within submerged parts of the Fukushima Daiichi plant’s Unit 3 reactor, the robot sent back 16 hours worth of images of massive, lava-like fuel deposits on the floor of the pedestal, a part of the reactor that sits underneath and supports the core….

The discovery is key to determining how to further advance the cleanup of the plant, a process that is expected to take decades.  “This was the first time that we could confirm the status inside the pedestal,” TEPCO spokesperson Maki Murayama said. “This is a big step towards the decommission process.”..

Having entered the stricken Pressure Containment Vessel (PCV) through a pipe designed to prevent the escape of radioactive gas, the robot descended into the cooling water which accumulated following the accident.
The device was equipped with thrusters to navigate through the water, and featured front and rear cameras.  The small “radiation-hardened, screw-driven” submersible robot was designed to fit through the narrow, 14-centimeter (5.5-inch) diameter entrance of the pipe, according to the Tokyo-based International Research Institute for Nuclear Decommissioning (IRID), which developed the device alongside technology company Toshiba.

As the robot navigates through the ruined reactor, melted equipment and the fuel deposits can be seen.

The mission was launched after previous photographic inspection of the Unit 3 reactor suggested that, “during the accident, fuel assemblies melted from the excess heat, dropping from their original position down to the pedestal area,” according to a statement released by TEPCO.

Excerpt from Euan McKirdy and Yoko Wakatsuki, Fukushima robot reveals first sign of melted fuel in submerged reactor, CNN, July 24, 2017

Not for the Fainthearted: total nuclear waste at Fukushima

Rubble Japan earthquake. image from wikipedia

Each form of waste at the Fukushima Daiichi Nuclear Power Station, where three reactors melted down after an earthquake and a tsunami on March 11, 2011, presents its own challenges.

400 Tons of Contaminated Water Per Day
The Tokyo Electric Power Company is pumping water nonstop through the three reactors to cool melted fuel that remains too hot and radioactive to remove. About 400 tons of water pass through the reactors every day, including groundwater that seeps in. The water picks up radiation in the reactors and then is diverted into a decontamination facility.  But the decontamination filters cannot remove all the radioactive material. So for now, all this water is being stored in 1,000 gray, blue and white tanks on the grounds. The tanks already hold 962,000 tons of contaminated water, and Tokyo Electric is installing more tanks. It is also trying to slow the flow of groundwater through the reactors by building an underground ice wall.

Within a few years, though, and no one is sure exactly when, the plant may run out of room to store the contaminated water. “We cannot continue to build tanks forever,” said Shigenori Hata, an official at the Ministry of Economy, Trade and Industry.  The authorities are debating whether it might be acceptable, given the relatively low radioactive levels in the water, to dilute the contaminated water and then dump it into the ocean. But local fishermen are vehemently opposed. Many people still do not trust Tokyo Electric because of its bungled response to the disaster, the worst nuclear accident since Chernobyl.

3,519 Containers of Radioactive Sludge
The process of decontaminating the water leaves radioactive sludge trapped in filters, which are being held in thousands of containers of different sizes.Tokyo Electric says it cannot quantify the amount of radioactive sludge being generated. But it says it is experimenting with what to do with it, including mixing it with cement or iron. Then it will have to decide how to store it.

64,700 Cubic Meters of Discarded Protective Clothing
The estimated 6,000 cleanup workers at the site put on new protective gear every day. These hazmat suits, face masks, rubber gloves and shoe coverings are thrown out at the end of each shift. The clothing is compressed and stored in 1,000 steel boxes stacked around the site.To date, more than 64,700 cubic meters of gear has been discarded, the equivalent of 17 million one-gallon containers. Tokyo Electric says it will eventually incinerate all this contaminated clothing to reduce the space needed to store it.

Branches and Logs From 220 Acres of Deforested Land
The plant’s grounds were once dotted with trees, and a portion was even designated as a bird sanctuary. But workers have cleared about 220 acres of trees since the meltdown spewed radiation over them.Now, piles of branches and tree trunks are stacked all over the site. Officials say there are about 80,000 cubic meters of this waste, and all of it will have to be incinerated and stored someday.

200,400 Cubic Meters of Radioactive Rubble
Explosions during the meltdown filled the reactors with rubble. Workers and robots are slowly and carefully trying to remove this tangled mass of crushed concrete, pipes, hoses and metal.  Tokyo Electric estimates that more than 200,400 cubic meters of rubble — all of it radioactive — have been removed so far and stored in custom-made steel boxes. That is the equivalent of about 3,000 standard 40-foot shipping containers.

3.5 Billion Gallons of Soil

Thousands of plastic garbage bags sit in neat rows in the fields and abandoned towns surrounding the Fukushima plant. They contain soil that was scraped from land that was exposed to radiation in the days after the accident.  Japan’s Ministry of the Environment estimates that it has bagged 3.5 billion gallons of soil, and plans to collect much more. It will eventually incinerate some of the soil, but that will only reduce the volume of the radioactive waste, not eliminate it.  The ministry has already begun building a massive, interim storage facility in Fukushima prefecture and negotiating with 2,360 landowners for the thousands of acres needed to complete it. And that is not even a long-term solution: The government says that after 30 years it will need another site — or sites — to store radioactive waste.

1,573 Nuclear Fuel Rods
The ultimate goal of the cleanup is to cool and, if possible, remove the uranium and plutonium fuel that was inside the three reactors at the time of the disaster.  Hundreds of spent fuel rods are in cooling pools inside the reactors, and the company hopes to have cleared away enough rubble to begin removing them next year. The much bigger challenge will be removing the fuel that was in use in the reactor core at the time of the meltdown.

The condition and location of this molten fuel debris are still largely unknown. In one reactor where a robot was sent in January, much of the melted fuel is believed to have burned through the bottom of the inner reactor vessel and burrowed into the thick concrete foundation of the containment structure.  The plan is to completely seal the containment vessels, fill them with water and use robots to find and remove the molten fuel debris. But the rubble, the lethal levels of radiation and the risk of letting radiation escape make this an exceedingly difficult task.

In January 2017, the robot sent into one of the reactors discovered radiation levels high enough to kill a person in less than a minute. Another had to be abandoned last month after debris blocked its path and radiation disabled it.

Tokyo Electric hopes to begin removing fuel debris from the reactor cores in 2021. The entire effort could take decades. Some say the radioactive material may prove impossible to remove safely and have suggested leaving it and entombing Fukushima under a concrete and steel sarcophagus like the one used at Chernobyl.

But the Japanese government and Tokyo Electric say they are committed to removing all the waste and cleaning the site, estimated at a cost of $188.6 billion.

Excerpts from MOTOKO RICH, Struggling With Japan’s Nuclear Waste, Six Years After Disaster, Mar. 11, 2017

The Devil’s Scenario for the End of Tokyo: Fukushima

Spent fuel pool at nuclear plant ....before an accident.  Image from wikipedia

By late March 2011… after tsunami struck the Fukushima Daiichi plant—it was far from obvious that the accident was under control and the worst was over. Chief Cabinet Secretary Yukio Edano feared that radioactive material releases from the Fukushima Daiichi plant and its sister plant (Fukushima Daini) located some 12 km south could threaten the entire population
of eastern Japan: “That was the devil’s scenario that was on my mind. Common sense
dictated that, if that came to pass, then it was the end of Tokyo.”

Prime Minister Naoto Kan asked Dr. Shunsuke Kondo, then-chairman of the Japanese Atomic Energy Commission, to prepare a report on worst-case scenarios from the accidenta .  Dr. Kondo led a 3-day study involving other Japanese experts and submitted his report (Kondo, 2011) to the prime minister on March 25, 2011. The existence of the report was initially kept secret because of the frightening nature of the scenarios it described. An article in the Japan Times quoted a senior government official as saying, “The content [of the report] was
so shocking that we decided to treat it as if it didn’t exist.” …
One of the scenarios involved a self-sustaining zirconium cladding fire in the Unit 4 spent fuel pool. Radioactive material releases from the fire were estimated to cause extensive contamination of a 50- to 70-km region around the Fukushima Daiichi plant with hotspots significant enough to require evacuations up to 110 km from the plant. Voluntary evacuations were envisioned out to 200 km because of elevated dose levels. If release from other spent fuel pools occurred, then contamination could extend as far as Tokyo,…There was particular concern that the zirconium cladding fire could produce enough heat to melt the stored fuel, allowing it to flow to the bottom of the pool, melt through the pool liner and concrete
bottom, and flow into the reactor building.

Lessons Learned from the Fukushima Daiichi Accident for Spent Fuel Storage: The U.S. nuclear industry and its regulator should give additional attention to improving the ability of plant operators to measure real-time conditions in spent fuel pools and maintain adequate cooling of stored spent fuel during severe accidents and terrorist attacks. These improvements should include hardened and redundant physical surveillance systems (e.g., cameras), radiation monitors, pool temperature monitors, pool water-level monitors, and means to deliver pool makeup water or sprays even when physical access to the pools is limited by facility damage or high radiation levels….

[At nuclear power plants there must be…adequate separation of plant safety and  security systems so that security systems can continue to function independently if safety systems are damaged. In particular, security systems need to have independent, redundant, and protected power sources…

Excerpts from Lessons Learned from the Fukushima Accident for Improving
Safety and Security of U.S. Nuclear Plants: Phase 2, US National Academies, 2016

Radioactive Boars and Malware, Nuclear Power Plants Germany

Wild Boar, image from wikipedia

A computer virus has been found in a nuclear power plant in Bavaria…The virus was found in Block B of the nuclear reactor at Gundremmingen in western Bavaria, a statement released by the power plant said.  The malware is well known to IT specialists and it attempts to create a connection to the internet without the user of the computer choosing to do so, the statement added…[T]he virus posed no danger to the public as all the computers which are responsible for controlling the plant are disconnected from one another and not connected to the internet. The virus is also not capable of manipulating the functions of the power plant, the statement claims. State authorities have been informed about the issues and specialists from the energy firm RWE are examining the computer system to asses how it became infected with the virus..

Germans are very sensitive to the dangers of nuclear technology,.. As recent as 2010, officials found traces of radioactivity connected to the 1986 Chernobyl catastrophe in German wildlife, like wild boar.,,,Shortly after the Fukushima meltdown in 2011, Chancellor Angela Merkel announced that the country would phase out nuclear power by 2021….

Several newspapers reported that the terrorists behind the Paris attacks had the plans for a German nuclear facility, a claim later denied by German intelligence. Then, days later, it was found that inspectors responsible for carrying out safety checks at two nuclear plants had submitted fake reports.

Excerpts from Computer Virus in Bavarian Nuclear Plant, http://www.thelocal.de/, Apr. 26, 2016

Nothing Outlasts the Fukushima Disaster: it keeps going and going….

energizer

As Prime Minister Shinzo Abe moves to reopen Japanese nuclear plants that were all shut after the disaster on March 11, 2011, a distrustful public is pushing back. A court on March 9, 2016ordered Kansai Electric Power Co. to halt two of the four reactors that have been restarted, saying the utility had failed to show the public they were safe. The utility called the ruling “unacceptable” and said it would appeal….However, near the ruined Fukushima reactors……Growing swaths of land are covered with black bags full of slightly radioactive soil.

The hardest parts of the cleanup haven’t even begun. Tepco, as Tokyo Electric is known, has yet to draw up plans for removing highly radioactive nuclear fuel that melted through steel containment vessels and now sits at the bottom of three Fukushima reactors.The company estimates that the nearly $20 billion job of decommissioning the plant could take another three or four decades. That is not counting damages and cleanup costs expected to reach some $100 billion or more, including about $50 billion paid to evacuees. Legal wrangling over the disaster continues. In February 2016, three former Tepco executives were charged with professional negligence.

Tepco also is working to reduce a total 400 tons of rain and groundwater that breach the plant’s defenses daily, becoming contaminated and requiring treatment and storage. But a wall of frozen earth meant to reduce the flow has run into resistance from regulators.On large parts of the site, workers can now walk around without full-face shields or hazmat suits, using simple surgical masks for protection.Fukushima was once a prized post for elite engineers and technicians in Japan’s nuclear heyday. Now, unskilled laborers make up the bulk of a workforce of about 6,000 workers, down from a peak of 7,450 in 2014. “There’s a constant stream of people who can’t find work elsewhere,” said Hiroyuki Watanabe, a Communist city councilman in Iwaki, about 30 miles away. “They drift and collect in Fukushima.”…

Looking ahead, the biggest issue remains the reactors. No one knows exactly where the molten nuclear debris sits or how to clean it. Humans couldn’t survive a journey inside the containment vessels, so Tepco hopes to use robots guided by computer simulations and video images. But two attempts had to be abandoned after the robots got tripped up on rubble.“The nature of debris may depend on when the nuclear fuel and concrete reacted,” said Pascal Piluso, an official of France’s Alternative Energies and Atomic Energy Commission. “We are talking about extremely varied and complex debris.”….A government panel recently questioned Tepco’s ability to tackle the daunting task of decommissioning while seeking profit for its shareholders. The disaster nearly pushed the company to bankruptcy, prompting the government to buoy it with ¥1 trillion ($9 billion  (really????) in public money and pledge government grants and guarantees to help Tepco compensate victims.”…

Excerpts  from Fukushima Still Rattles Japan, Five Years After Nuclear Disaster, Wall Street Journal, Mar. 8, 2016