Tag Archives: Fukushima nuclear fuel rods

Essence of Fear: Fukushima Radioactive Water Dump in Pacific Ocean

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Nearly three-fourths of South Koreans say they will eat less seafood after Japan starts releasing Fukushima radioactive wastewater into the Pacific Ocean. The price of sea salt in the country skyrocketed and government reserves were released, as panic buying ahead of the nuclear-water dump emptied out the shelves…Japan’s plan to release the water into the sea after diluting the radioactive elements to what it says are safe levels has been affirmed by the International Atomic Energy Agency (IAEA), a United Nations body. The agency’s chief, Rafael Grossi, personally delivered the final IAEA report to Japanese Prime Minister Fumio Kishida this week. The report said radionuclides would be released at a lower level than those produced by natural processes and would have a negligible impact on the environment.

But….“The field of nuclear power is contaminated with fear,” said Michael Edwards, a clinical psychiatrist in Sydney who interviewed Fukushima residents following the nuclear accident. “Psychologically, people do not really understand and trust science, and know science can be an instrument of government.”…Beijing’s Foreign Ministry has slammed the Fukushima wastewater plan, accusing Japan of treating the surrounding ocean as the country’s own “private sewer.” China has expanded restrictions on food imports from Japan, which include a ban on food products from Fukushima and nine other prefectures.

Excerpts from Dasl Yoon and Miho Inada ‘How Could I Feel Safe?’ Japan’s Dumping of Radioactive Fukushima Water Stirs Fear, Anger, WSJ, July 7, 2023

Unthinkable: What Happens When Water Floods a Nuclear Plant

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As the 9.0 magnitude earthquake hit the Japanese shore, the reactors of the Fukushima Daiichi nuclear power plant shut down automatically to control the nuclear fission. The electrical lines collapsed, but the plant responded as designed, and the earthquake itself did not cause any other problems. The tsunami it triggered, however, did.

“The reactors were robust, seismically speaking,” said Gustavo Caruso, Director of the IAEA’s Office of Safety and Security Coordination. “But they were vulnerable to the high tsunami waves.” When the flooding hit, the ‘tsunami walls’ made to protect the plant from such events were too low to prevent the sea water from entering the plant. The water’s strength destroyed some of the structures, and entered the diesel generator room — which was built lower and at a closer distance to sea level than other plants in Japan — affecting Units 1, 2 and 3. “The diesel generators are essential for maintaining the plant’s electrical supplies in emergency situations,” said Pal Vincze, Head of the Nuclear Power Engineering Section at the IAEA. “They were drowned.”

If the diesel generator is affected, special batteries can be used to generate electricity, but these have a limited capacity, and, in the case of Fukushima Daiichi, some were also flooded. “In Japan, they put up a heroic fight to get the electrical systems up and running again, but it wasn’t enough,” Vincze added.

Without functioning instrumentation and control systems, or electrical power or cooling capabilities, the overheated fuel melted, sank to the bottom of the reactors, and breached the reactor vessels, leading to three meltdowns. In addition, data logs and vital systems operated by safety parameters were also flooded, which meant that there was no way for the operator to monitor what was going on inside the reactors.

As stated in the IAEA report on the Fukushima Daiichi accident, “a major factor that contributed to the accident was the widespread assumption in Japan that its nuclear power plants were so safe that an accident of this magnitude was simply unthinkable. But…When planning, designing and constructing the plant, experts did not properly take into consideration past tsunami experiences… “It must be noted that the combination of an earthquake of this magnitude and a tsunami is extremely rare, but unfortunately this is what happened.”…

Excerpt from Laura Gil Fukushima Daiichi: The Accident, IAEA Bulletin, Mar. 2021

The Fukushima Nuclear Meltdown: Ten Years — and Counting

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A resolution to the crisis at the Fukushima Daiichi nuclear power plant remains a distant goal a decade after three of its reactors melted down. The most challenging part of the cleanup—removing molten nuclear fuel from each reactor—has yet to begin because of high radiation inside the reactor buildings, putting the targeted decommissioning of the plant by 2051 into doubt.

More than 80% of the Japanese public doesn’t feel significant progress is being made and is concerned about further accidents because of recent events. On Feb. 13, 2021 a large earthquake centered near Fukushima, an aftershock of the one 10 years ago, caused water to slosh out of a tank containing spent fuel rods, which must be kept submerged to avoid overheating. A week later, a fish caught off the coast of Fukushima was found to contain 10 times the allowed level of radioactive cesium…This incident shows how risks from the plant continue to weigh on those who live and work nearby. 

“We are still struggling with harmful rumors from the nuclear plant accident,” said Tadaaki Sawada, a spokesman for the federation of Fukushima fishery cooperatives. “How many more years will it continue?”…By several measures, the worst nuclear disaster since the Chernobyl accident in 1986 has been contained. Only around 2% of Fukushima prefecture, or state, is still a no-go area, down from 12% immediately after the disaster. An extensive decontamination process removed topsoil from areas around the plant. Still, thousands of people remain forced out of towns closest to the plant.

In 2020, plant operator Tokyo Electric Power Co., known as Tepco, and the government were close to a decision to start releasing into the sea over a million cubic meters of water from the plant, but plans were suspended amid opposition from local fishermen and concerns raised by neighboring countries. Contaminated rain and groundwater is stored in large tanks that dominate one side of the plant site. Once treated to remove most radioactive elements, the water still contains tritium, a form of hydrogen that emits a weak form of radiation. Tritium is regularly released into the sea and air from nuclear plants around the world after dilution.

Inspectors from the International Atomic Energy Agency visited the Fukushima plant in 2020 and said disposal of the treated water into the sea would be in line with international practice. “A decision on the disposition path should be taken urgently” to keep the overall decommissioning on track, the IAEA said.

The most challenging part of the cleanup—removing molten nuclear fuel from each reactor—has yet to begin…Tepco has yet to get a clear picture of the location of molten fuel in the reactors because the levels of radiation are damaging even to robots…Gov. Uchibori said that gaining an accurate grasp of the molten-fuel situation was critical to making headway. “If you look at the entire process, right now we are still around the starting point of decommissioning,” he said.

Excerpts from Alastair Gale Fukushima Nuclear Cleanup Is Just Beginning a Decade After Disaster, 

Radioactive Water Dumping and Human Rights

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In the aftermath of the Fukushima Daiichi nuclear disaster, [UN Special Rapporteurs  have] consistently raised concerns about the approaches taken by the government of Japan. UN Special Rapporteurs have been concerned that raising of “acceptable limits” of radiation exposure to urge resettlement violated the government’s human rights obligations to children.

UN Special Rapporteurs have been concerned of the possible exploitation of migrants and the poor for radioactive decontamination work. Their most recent concern is how the government used the COVID-19 crisis to dramatically accelerate its timeline for deciding whether to dump radioactive wastewater accumulating at Fukushima Daiichi in the ocean

The communities of Fukushima, so devastated by the tragic events of March 11, 2011, have expressed their concerns and opposition to the discharge of the contaminated water into their environment. It is their human right to an environment that allows for living a life in dignity, to enjoy their culture, and to not be exposed deliberately to additional radioactive contamination. Those rights should be fully respected and not be disregarded by the government in Tokyo. The discharge of nuclear waste to the ocean could damage Japan’s international relations. Neighboring countries are already concerned about the release of large volumes of radioactive tritium and other contaminants in the wastewater.

Japan has a duty under international law to prevent transboundary environmental harm. More specifically, under the London Convention, Japan has an obligation to take precaution with the respect to the dumping of waste in the ocean.

Indigenous peoples have an internationally recognized right to free, prior and informed consent. This includes the disposal of waste in their waters and actions that may contaminate their food. No matter how small the Japanese government believes this contamination will be of their water and food, there is an unquestionable obligation to consult with potentially affected indigenous peoples that it has not met…The disaster of 2011 cannot be undone. However, Japan still has an opportunity to minimize the damage…There are grave risks to the livelihoods of fishermen in Japan and also to its international reputation. Again, I urge the Japanese government to think twice about its legacy: as a true champion of human rights and the environment, or not.

Excerpts from, Baskut Tuncak [UN Rapporteur], Fukushima nuclear waste decision also a human rights issue, Kyodo News, July 8, 2020

Forever Fukushima: Cleaning Up the Huge Mess

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By the end of 2019, Japan further delayed the removal of thousands of spent fuel units that remain in cooling pools since the 2011 disaster The government and the plant operator, Tokyo Electric Power Co., are keeping a 30- to 40-year completion target.

More than 4,700 units of fuel rods remain at the three melted reactors and two others that survived the 2011 earthquake and tsunami. They pose a high risk because their storage pools are uncovered and a loss of water in case of another major disaster could cause the fuel rods to melt, releasing massive radiation. Their removal at Units 1 and 2, after repeated delays, is now postponed by up to 10 years from the initial target of 2018, with more preparation needed to reduce radiation and clear debris and other risks.

Fuel rod removal at the Unit 1 reactor pool will begin sometime in 2027-2028, after debris is cleaned up and a huge rooftop cover installed to contain radioactive dust. Fuel removal at Unit 2 pool is to begin in 2024-2026. Work at the Unit 3 reactor pool began in April 2019 and all 566 units will be removed by March 2021. TEPCO has emptied the pool at Unit 4, which was offline and only suffered building damage, and aims to have all remaining rods in reactor pools removed by 2031 for safer storage in dry casks.

TEPCO has been unable to release the 1.2 million tons of treated but still radioactive water kept in nearly 1,000 tanks at the plant, fearing public repercussions and the impact on the area’s struggling fishing and agriculture. The amount of water is growing by 170 tons daily because it is used to cool the melted fuel inside the reactors.

The Ministry of Economy, Trade and Industry recently drafted a proposal to release the water to the sea or the air, or a combination of both. TEPCO says it can only store up to 1.37 million tons, or until the summer of 2022. Time is limited because preparation is needed before any water release. TEPCO and the government say the tanks pose risks if they were to spill their contents in another major earthquake, tsunami or flood…. The water is still somewhat contaminated, but TEPCO says further treatment can remove all but radioactive tritium to levels allowed for release. Experts say tritium is not harmful to humans in small amounts and has been routinely released from nuclear plants around the world.

Removing an estimated 880 tons of molten fuel from Fukushima’s three melted reactors is the toughest and unprecedented challenge. It’s six times the amount dealt with in the aftermath of the 1979 Three Mile Island partial core melt in the United States.  Removal is to begin in 2021 at Unit 2, where robotic probes have made more progress than at Units 1 and 3. A robotic arm was developed to enter the reactor from the side to reach the melted fuel, which has largely fallen to the bottom of the primary containment vessel… The first decade through 2031 is a crucial phase that will affect future progress…

Japan has yet to develop a plan to dispose of the highly radioactive melted fuel and other debris that come out of the reactors. TEPCO will compile a plan for those after the first decade of melted fuel removal. Managing the waste will require new technologies to reduce its volume and toxicity. TEPCO and the government say they plan to build a site to store waste and debris removed from the reactors, but finding one and obtaining public consent will be difficult.

Additionally, there will be an estimated 770,000 tons of solid radioactive waste by 2030, including contaminated debris and soil, sludge from water treatment, scrapped tanks and other waste. They will be sorted, treated and compacted for safe storage under a plan to be compiled by 2028.

The government says Fukushima’s decommissioning cost is estimated at 8 trillion yen ($73 billion), though adding compensation, decontamination of surrounding areas and medium-term storage facilities would bring the total to an estimated 22 trillion yen ($200 billion). The Japan Center for Economic Research, a think tank, estimates that decommissioning alone would cost 51 trillion yen ($470 billion) if the water is not released and tritium removal technology is pursued.

More than 10,000 workers will be needed annually in coming years, about one third assigned to work related to the radioactive water. 

Excerpts from MARI YAMAGUCHI,  Japan revises Fukushima cleanup plan, delays key steps, Associated Press, Dec. 27, 2019

Melted Nuclear Fuel at Fukushima

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jA 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

Nuclear Waste at Fukushima: total amount

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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