Tag Archives: Fukushima nuclear disaster

A Never-Ending Disaster: radioactive water at Fukushima

A Greenpeace report details how plans to discharge over 1 million tonnes of highly contaminated water into the Pacific Ocean was proposed by a Japanese government task force.  According to Greenpeace.

“The decision not to develop water processing technology that could remove radioactive tritium was motivated by short term cost cutting not protection of the Pacific ocean environment or the health and livelihoods of communities along the Fukushima coast,” said Kazue Suzuki, Energy Campaigner at Greenpeace Japan. “  The report concludes that the water crisis remains unresolved, and will be for the foreseeable future. The only viable option to protect the environment and the communities along the Fukushima coast being long term storage for the contaminated water.

The discharge option for water containing high levels of radioactive tritium was recommended as least cost by the Government’s Tritiated Water Task Force and promoted by Japan’s Nuclear Regulation Authority (NRA). The Task Force concluded in 2016 that “sea discharge would cost 3.4 billion yen (US$30 million) and take seven years and four months to complete. It concluded that this was cheapest and quickest of the five methods.” However, technical proposals for removing tritium were submitted to the same Government Task Force by multiple nuclear companies with estimated costs ranging from US$2-US$20 billion to US$50-US$180 billion depending on the technology used. These were dismissed as not viable but without detailed technical consideration.

TEPCO has claimed since 2013 that its ALPS technology would reduce radioactivity levels “to lower than the permissible level for discharge.” However, in September 2018 TEPCO admitted that the processing of over 800,000 tons of contaminated water in 1000 storage tanks, including strontium, had failed to remove radioactivity to below regulatory limits, including for strontium-90, a bone seeking radionuclide that causes cancer. TEPCO knew of the failure of the technology from 2013. The Greenpeace report details technical problems with the ALPS system.

The Fukushima Daiichi site, due its location, is subject to massive groundwater contamination which TEPCO has also failed to stop. Each week an additional 2-4000 tonnes of contaminated water is added to the storage tanks.

Excerpts from Technical failures increase risk of contaminated Fukushima water discharge into Pacific, Greenpeace Press Release,  Jan. 22, 2019

Devil’s Idea for Tokyo’s End: Fukushima

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

Dismantling Nuclear Reactors at Fukushima

In the aftermath of the Fukushima nuclear disaster in 2011, Naraha decided to oppose nuclear energy and call for the closure of the Fukushima No. 2 nuclear power plant that it co-hosts on the coast of the prefecture.  Since the 1970s, the town has been home to the No. 2 plant, which first went into service in 1982.  For decades, Naraha has received central government grants and subsidies for hosting the No. 2 plant, as well as tax revenues from TEPCO and its affiliates operating in the town.The plant also employed 860 people, many of them from Naraha and its surrounding communities.

Naraha had a population of about 8,000 before the Great East Japan Earthquake and tsunami caused the triple meltdown at TEPCO’s Fukushima No. 1 nuclear plant in March 2011. The crippled plant is located within 20 kilometers from Nahara.  The quake and tsunami also created a scare at the No. 2 plant by leaving the facility with only a limited power supply from external sources and emergency diesel generators to cool the reactors. But the plant brought the situation under control.

After long remaining silent about the fate of the No. 2 plant, TEPCO decided to retire all of its four reactors, which were approaching their legal operating limit of 40 years. If the power company wanted to continue operations at the plant, it would have to spend hundreds of billions of yen on upgrades to meet the more stringent safety standards that were set after the accident at the No. 1 plant…

Although Naraha and Tomioka officials share concerns about their municipalities’ financial futures, they see a silver lining in the situation at the Fukushima No. 1 nuclear plant.  Both towns have served as front-line bases for workers involved in decommissioning of the stricken plant.  About 5,000 workers a day who are involved in the decommissioning effort provide steady business for convenience stores and other shops in the two towns. Business hotels, dorms and apartment buildings have been built in the towns and neighboring communities to accommodate the workers. Work to dismantle the No. 1 plant is expected to take decades to complete. Local officials said the closure of the No. 2 plant could bring about a similar economic boon. “Decommissioning can become a major industry,” Naraha Mayor Matsumoto said.

Excerpts from  Nuclear plant closure brings hope, despair to Fukushima town
THE ASAHI SHIMBUN, October 18, 2018

The Burial: nuclear waste of Fukushima

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

The Class Actions of Fukushima Fefugees

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

Melted Nuclear Fuel at Fukushima

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

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