Tag Archives: Fukushima Dai-ichi nuclear-power plant

Fukushima in 2018: Radioactive Mud

Radioactive cesium from the crippled Fukushima No. 1 nuclear power plant continued to flow into Tokyo Bay for five years after the disaster unfolded in March 2011, according to a researcher.  Hideo Yamazaki, a former professor of environmental analysis at Kindai University, led the study on hazardous materials that spewed from the nuclear plant after it was hit by the Great East Japan Earthquake and tsunami on March 11, 2011.

Five months after disaster caused the triple meltdown at the plant, Yamazaki detected 20,100 becquerels of cesium per square meter in mud collected at the mouth of the Kyu-Edogawa river, which empties into Tokyo Bay.  In July 2016, the study team detected a maximum 104,000 becquerels of cesium per square meter from mud collected in the same area of the bay, Yamazaki said.

He said cesium released in the early stages of the Fukushima disaster remained on the ground upstream of the river, such as in Chiba Prefecture. The radioactive substances were eventually washed into the river and carried to Tokyo Bay, where they accumulated in the mud, he said.

On a per kilogram basis, the maximum level of radioactivity of cesium detected in mud that was dried in the July 2016 study was 350 becquerels.  The government says soil with 8,000 becquerels or lower of radioactive cesium per kilogram can be used in road construction and other purposes.  The amount of radioactive cesium in fish in Tokyo remains lower than 100 becquerels per kilogram, the national safety standard for consumption.

Excerpts from  NOBUTARO KAJI,  Cesium from Fukushima flowed to Tokyo Bay for 5 years, June 7, 2018

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

Radioactive Beaches: Fukushima at 2017

Kotohiki Beach, Japan. image from wikipedia

Six years after the Fukushima nuclear reactor disaster in Japan, radioactive material is leaching into the Pacific Ocean from an unexpected place. Some of the highest levels of radioactive cesium-137, a major by-product of nuclear power generation, are now found in the somewhat salty groundwater beneath sand beaches tens of kilometers away, a new study shows.

Scientists tested for radioactivity at eight different beaches within 100 kilometers of the plant, which experienced three reactor meltdowns when an earthquake and tsunami on March 11, 2011, knocked out its power. Oceans, rivers and fresh groundwater sources are typically monitored for radioactivity following a nuclear accident, but several years following the disaster, those weren’t the most contaminated water sources. Instead, brackish groundwater underneath the beaches has accumulated the second highest levels of the radioactive element (surpassed only by the groundwater directly beneath the reactor).

In the wake of the 2011 accident, seawater tainted with high levels of cesium-137 probably traveled along the coast and lapped against these beaches, proposes study coauthor Virginie Sanial, who did the work while at Woods Hole Oceanographic Institution in Massachusetts. Some cesium stuck to the sand and, over time, percolated down to the brackish groundwater beneath. Now, the radioactive material is steadily making its way back into the ocean. The groundwater is releasing the cesium into the coastal ocean at a rate that’s on par with the leakage of cesium into the ocean from the reactor site itself, Sanial’s team estimates.

Excerpts from Radioactive material from Fukushima disaster turns up in a surprising place, Science News, Oct. 2, 2017

See also Unexpected source of Fukushima-derived radiocesium to the coastal ocean of Japan

Throwing Money at Nuclear Waste

Japan seeks final resting place for highly radioactive nuclear waste
…[W]ith a number of Japan’s nuclear reactors closed down for good in the wake of the Fukushima accident, the need for a permanent storage site is more pressing than ever.

The disaster, in which a 13-meter tsunami triggered by an off-shore earthquake crippled four reactors at the plant and caused massive amounts of radioactivity to escape into the atmosphere, also underlined just how seismically unstable the Japanese archipelago is and the need for the repository to be completely safe for 100,000 years.

“They have been trying to get this plan of the ground for years and one thing they tried was to offer money to any town or village that agreed to even undergo a survey to see if their location was suitable,” she said.  “There were a number of mayors who accepted the proposal because they wanted the money – even though they had no intention of ever agreeing to host the storage site – but the backlash from their constituents was fast and it was furious,” Smith added.  “In every case, those mayors reversed their decisions and the government has got nowhere,” she said. “But I fear that means that sooner or later they are just going to make a decision on a site and order the community to accept it.”

The security requirements of the facility will be exacting, the government has stated, and the site will need to be at least 300 meters beneath the surface in a part of the country that is not subject to seismic activity from active faults or volcanoes. It must also be safe from the effects of erosion and away from oil and coal fields. Another consideration is access and sites within 20 km of the coast are preferred.

The facility will need to be able to hold 25,000 canisters of vitrified high-level waste, while more waste will be produced as the nation’s nuclear reactors are slowly brought back online after being mothballed since 2011 for extensive assessments of their safety and ability to withstand a natural disaster on the same scale as the magnitude-9 earthquake that struck Fukushima.

When it is released, the government’s list is likely to include places in Tohoku and Hokkaido as among the most suitable sites, because both are relatively less populated than central areas of the country and are in need of revitalization efforts. Parts of Tohoku close to the Fukushima plant may eventually be chosen because they are still heavily contaminated with radiation from the accident.

Excerpts from Japan seeks final resting place for highly radioactive nuclear waste, Deutsche Welle, May 4, 2017

When the End is not Near: Fukushima 2017

 black lumps on wire-mesh grating found at Fukushima, Jan 30, 2017

Hopes have been raised for a breakthrough in the decommissioning of the wrecked Fukushima Daiichi nuclear plant after its operator said it may have discovered melted fuel beneath a reactor, almost six years after the plant suffered a triple meltdown.  Tokyo Electric Power (Tepco) said on January 30, 2017 that a remote camera appeared to have found the debris beneath the badly damaged No 2 reactor, where radiation levels remain dangerously high. Locating the fuel is the first step towards removing it.  If Tepco can confirm that the black mass comprises melted fuel, it would represent a significant breakthrough in a recovery effort that has been hit by mishaps, the buildup of huge quantities of contaminated water, and soaring costs….Using a remotely controlled camera attached to the end of a 10.5-metre-long telescopic arm, Tepco technicians located black lumps on wire-mesh grating just below the reactor’s pressure vessel, local media reported.

The company plans to send a scorpion-like robot equipped with cameras, radiation measuring equipment and a temperature gauge into the No 2 reactor containment vessel….Three previous attempts to use robots to locate melted fuel inside the same reactor ended in failure when the devices were rendered useless by radiation.

The delicate, potentially dangerous task of decommissioning the plant has barely begun, however.Japanese media said that plans to remove spent fuel from the No 3 reactor building had been delayed, while decommissioning the entire plant was expected to take at least 40 years.  In December 2016, the government said the estimated cost of decommissioning the plant and decontaminating the surrounding area, as well as paying compensation and storing radioactive waste, had risen to 21.5 trillion yen ($187bn), nearly double an estimate released in 2013.

Excerpts Possible nuclear fuel find raises hopes of Fukushima plant breakthrough, Guardian, Jan. 30, 2017

Cleaning Radioactive Water

tritium. Image from wikipedia

Russia’s nuclear energy giant Rosatom’s subsidiary RosRAO has created a prototype water decontamination plant for use at Tokyo Electric Power Co. Holdings’ Fukushima Daiichi nuclear power station — the site of Japan’s largest nuclear disaster in March 2011. The scrubbing facility, unveiled in June 2014, is capable of removing tritium, or radioactive hydrogen, from nuclear-tainted water, something beyond the capabilities of the Fukushima plant’s current cleanup equipment. Distillation and electrolysis isolate and concentrate the isotope, which is then locked away in titanium. Experiments under conditions similar to those on the ground reportedly show the technology cutting wastewater’s radioactive material content to one-6,000th the initial level, making it safe for human consumption or release into the ocean.

Duplicating the facility near the Fukushima site and running it for the five years necessary to process 800,000 cu. meters of contaminated water would cost around $700 million in all. Companies in Japan and the U.S. are at work on their own facilities for tritium disposal, but the Russian plan’s cost and technological capability make it fully competitive, according to the project’s chief.

Rosatom has made other overtures to Japan. Executives from a mining and chemical unit have visited several times this year for talks with Japanese nuclear companies, aiming to cooperate on decommissioning the Fukushima plant and upgrading a reprocessing plant in Aomori Prefecture for spent nuclear fuel. Russia has amassed a wealth of expertise dealing with damaged nuclear reactors in the wake of the Chernobyl disaster, and would like Japan to draw on that knowledge, the subsidiary’s chief executive said.

Revving up nuclear technology exports is essential to re-energizing Russia’s domestic industry and breaking free of dependence on the resource sector, Moscow has decided. The nuclear business, along with the space industry, is one of the few tech-intensive sectors where the country is internationally competitive. President Vladimir Putin has leaned more heavily on leaders in Europe and emerging countries in recent years to agree to deals with Russia’s nuclear companies.

In Japan, the public has grown wary of nuclear energy since the accident, leaving demand for new plants in the country at next to nil. Yet Japan has more than 10 reactors slated for decommissioning, creating a market worth up to 1 trillion yen ($9.42 billion) by some calculations. Russia aims to use cooperation on the Fukushima plant to crack the broader market and grow its influence, a source at a French nuclear energy company said…

But Japanese Prime Minister Shinzo Abe nevertheless visited Russia in May 2016 for top-level talks despite U.S. objections, eager to make progress on territorial disputes over islands north of Hokkaido. Preparation is underway for another summit in the far-eastern city of Vladivostok in September 2016, as well as a visit by Putin to Japan before the year is out.
Excerpts from TAKAYUKI TANAKA, Japan nuclear cleanup next target in Russian economic offensive, Nikkei Asian Review, July 24, 2016

Leaking Radioactive Water into the Ocean