Tag Archives: Chernobyl

$2 Trillion Gamble: congested nuclear pools

This image captures the spread of radioactivity from a hypothetical fire in a high-density spent-fuel pool at the Peach Bottom Nuclear Power Plant in Pennsylvania. Based on the guidance from the U.S. Environmental Protection Agency and the experience from the Chernobyl and Fukushima accidents, populations in the red and orange areas would have to be relocated for many years, and many in the yellow area would relocate voluntarily. In this scenario, which is based on real weather patterns that occurred in July 2015, four major cities would be contaminated (New York City, Philadelphia, Baltimore and Washington, D.C.), resulting in the displacement of millions of people. (Photo from http://wws.princeton.edu/news-and-events/news/item/us-nuclear-regulators-greatly-underestimate-potential-nuclear-disaster).

The U.S. Nuclear Regulatory Commission (NRC) relied on faulty analysis to justify its refusal to adopt a critical measure for protecting Americans from the occurrence of a catastrophic nuclear-waste fire at any one of dozens of reactor sites around the country, according to an article in the May 26,  2017 issue of Science magazine. Fallout from such a fire could be considerably larger than the radioactive emissions from the 2011 Fukushima accident in Japan. Published by researchers from Princeton University and the Union of Concerned Scientists, the article argues that NRC inaction leaves the public at high risk from fires in spent-nuclear-fuel cooling pools at reactor sites. The pools—water-filled basins that store and cool used radioactive fuel rods—are so densely packed with nuclear waste that a fire could release enough radioactive material to contaminate an area twice the size of New Jersey. On average, radioactivity from such an accident could force approximately 8 million people to relocate and result in $2 trillion in damages….”The NRC has been pressured by the nuclear industry, directly and through Congress, to low-ball the potential consequences of a fire because of concerns that increased costs could result in shutting down more nuclear power plants,” said paper co-author Frank von Hippel, a senior research physicist at Princeton’s Program on Science and Global Security (SGS), based at the Woodrow Wilson School of Public and International Affairs. “Unfortunately, if there is no public outcry about this dangerous situation, the NRC will continue to bend to the industry’s wishes.”

Spent-fuel pools were brought into the spotlight following the March 2011 nuclear disaster in Fukushima, Japan…..”The Fukushima accident could have been a hundred times worse had there been a loss of the water covering the spent fuel in pools associated with each reactor,” von Hippel said. “That almost happened at Fukushima in Unit 4.”

In the aftermath of the Fukushima disaster, the NRC considered proposals for new safety requirements at U.S. plants. One was a measure prohibiting plant owners from densely packing spent-fuel pools, requiring them to expedite transfer of all spent fuel that has cooled in pools for at least five years to dry storage casks, which are inherently safer. Densely packed pools are highly vulnerable to catching fire and releasing huge amounts of radioactive material into the atmosphere.

The NRC analysis found that a fire in a spent-fuel pool at an average nuclear reactor site would cause $125 billion in damages, while expedited transfer of spent fuel to dry casks could reduce radioactive releases from pool fires by 99 percent. However, the agency decided the possibility of such a fire is so unlikely that it could not justify requiring plant owners to pay the estimated cost of $50 million per pool.

The NRC cost-benefit analysis assumed there would be no consequences from radioactive contamination beyond 50 miles from a fire. It also assumed that all contaminated areas could be effectively cleaned up within a year. Both of these assumptions are inconsistent with experience after the Chernobyl and Fukushima accidents.

In two previous articles, von Hippel and Schoeppner released figures that correct for these and other errors and omissions. They found that millions of residents in surrounding communities would have to relocate for years, resulting in total damages of $2 trillion—nearly 20 times the NRC’s result. Considering the nuclear industry is only legally liable for $13.6 billion, thanks to the Price Anderson Act of 1957, U.S. taxpayers would have to cover the remaining costs.

The authors point out that if the NRC does not take action to reduce this danger, Congress has the authority to fix the problem. Moreover, the authors suggest that states that provide subsidies to uneconomical nuclear reactors within their borders could also play a constructive role by making those subsidies available only for plants that agreed to carry out expedited transfer of spent fuel…

The paper, “Nuclear safety regulation in the post-Fukushima era,” was published May 26 in Science. For more information, see von Hippel and Schoeppner’s previous papers, “Reducing the Danger from Fires in Spent Fuel Pools” and “Economic Losses From a Fire in a Dense-Packed U.S. Spent Fuel Pool,” which were published in Science & Global Security in 2016 and 2017 respectively. The Science article builds upon the findings of a Congressionally-mandated review by the National Academy of Sciences, on which von Hippel served.

Excerpts from US nuclear regulators greatly underestimate potential for nuclear disaster, researchers say, Princeton University Woodrow Wilson  News, May 25,, 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

Chernobyl Nuclear Accident from 1986 to 2016

Chernobyl containment. . image from EBRD

A workforce of around 2,500 people is finishing a massive steel enclosure that will cover Chernobyl’s reactor 4, where the radioactive innards of the nuclear plant are encased in a concrete sarcophagus hastily built after the disaster.  If all goes to plan, the new structure—an arch more than 350 feet high and 500 feet long—will be slid into place late next year over the damaged reactor and its nuclear fuel, creating a leak-tight barrier designed to contain radioactive substances for at least the next 100 years.

The project, known as the New Safe Confinement,  is a feat of engineering.  [see also the Chernobyl Gallery] It will take two or three days to slide the 36,000-ton structure into place. The arch, which looks something like a dirigible hangar, is large enough to cover a dozen football fields. “You could put Wembley Stadium underneath here, with all the car parks,” said David Driscoll, the chief safety officer for the French consortium running the construction site.

Three decades ago, an army of workers scrambled to build a concrete sarcophagus around Chernobyl Reactor 4, which released a radioactive plume after a reactor fire and explosion on April 26, 1986.  At least 30 people died as an immediate result of the accident, which contaminated parts of Ukraine, Belarus and Russia and sent radioactive dust and debris over Europe. Pripyat, the company town of 50,000, was completely evacuated.

Emergency workers and evacuees received doses of radiation significantly above natural background levels, according to the World Health Organization. Researchers acknowledge high levels of thyroid cancer among people who were children at the time of the accident, from exposure to radioactive iodine…

Nicolas Caille, project director for Novarka, the consortium of Vinci SA and Bouygues SA, the French contractors running the project, said about 1,000 people work on a typical shift at the construction site, keeping to a schedule of 15 days in and 15 out….

A new facility to safely and securely store spent nuclear rods is being built at the nuclear power complex. The Interim Spent Fuel Storage Facility, or ISF2, is intended to store spent fuel rods for a minium of 100 years…..The Liquid Radioactive Waste Treatment Plant in Chernobyl…retrieves highly active liquids from their current tanks, processes them into a solid state and moves them to containers for long-term storage. …

Wildlife has flourished in the forest [surrounding Chernobyl], which is largely off limits to humans. Officials say species such as lynx, wild boar, wolves, elk, bear and European bison have rebounded.

Excerpts from Nathan Hodge, 30 Years After Chernobyl Disaster, an Arch Rises to Seal Melted Reactor, Wall Street Journal, Apr. 25, 2016

Germans to Decontaminate Ukraine, Nuclear Waste

image from http://www.dmt-group.com/en/services/engineering/nuclear-waste-disposal.html

A consortium of four German companies has been awarded a contract to improve infrastructure for managing radioactive waste, the rehabilitation of contaminated areas and the decommissioning of nuclear power plants in Ukraine.  The consortium – comprising Brenk Systemplanung, DMT, Plejades and TÜV Nord EnSys – was awarded the contract for the project, which is within the framework of the European Union-funded Instrument for Nuclear Safety Cooperation (INSC). The INSC is designed to support non-EU countries in improving nuclear safety. The contract will run for an initial two-year period and have a maximum budget of €1.5 million ($1.6 million).

According to the tender notice, the main objectives of the contract are to support the Ukrainian State Corporation ‘Radon’ in establishing an emergency response system for “radiation incidents involving unauthorized radioactive materials that are not related to nuclear power plant operation”. It also calls for the establishment of integrated, automated monitoring systems for radiation and environmental protection at Radon facilities, as well as the remediation of radioactive waste storage sites resulting from the Chernobyl nuclear power plant accident and situated outside the exclusion zone.

In a statement yesterday, DMT said it will jointly lead with TÜV Nord EnSys Hannover the assessment of some 50 radioactive waste storage sites.

Excerpts from German consortium awarded Ukrainian waste contract, World Nuclear News, Mar. 2, 2016

Who dares? population resettlement at Fukushima

Micrograph of thyroid cancer. image from wikipedia

By the time Fukushima prefecture finishes the task of decontaminating houses and farmland around the Dai-ichi plant, it will have spent an estimated $50 billion on the work.  Some argue it would have been wiser to have spent the money on resettling former residents elsewhere. Already many of the 80,000 or so people displaced from the areas around the plant have begun new lives. Those moving back are mainly elderly. Local officials expect that half of the evacuees, especially those with children who are more vulnerable to radiation, may never return.

Fear of radiation, and distrust of data from the government and from the Tokyo Electric Power Company (TEPCO), the Dai-ichi operator, on the risk it poses, are the biggest reasons. On October 20th, 2015 it was announced that a worker who had helped to contain the accident had developed cancer linked to the meltdown. It was the first such diagnosis, but a recent medical study found a huge leap in cases of thyroid cancer among children and adolescents in Fukushima prefecture since the catastrophe.

Public faith in Japan’s institutions suffered a severe blow as a result of the government’s bungled response to the accident in 2011. So when officials of Tamura city wanted to open the Miyakoji district in 2013, residents resisted and demanded more decontamination work.

A year after the lifting of the evacuation order on his village, Yuko Endo, the mayor of Kawauchi, says distrust is so widespread that he doubts his community will return even near to its former size. But he has visited the area around Chernobyl in Ukraine, the site of the world’s worst nuclear disaster 29 years ago. He says the sight there of abandoned villages resembling graveyards has stiffened his resolve to rebuild. Those who have now returned are still deeply sceptical about the assurances they receive. Many ask why, for instance, if the soil is safe, they must take their locally grown produce to be checked for radiation.

There is a particular ray of hope in Naraha—more of one than is evident in Miyakoji and Kawauchi. The town will benefit from jobs related to the decommissioning of the nearby nuclear plants, including Dai-ni, which got through the earthquake and tsunami relatively unscathed. Another of Naraha’s immediate projects is to erect new streetlights. It will be helped by dollops of government aid. Mr Matsumoto, the mayor, talks of luring people back by making his town much more attractive than it was before. But for now, many streetlights do not even work. It is dark at night and the atmosphere is eerie.

Nuclear Power in Japan: Back to the Nuclear zone, Economist, Oct. 24, 2015, at 39

Nuclear Accidents of the Future: the preparations


Three major atomic accidents [Three Mile Island US 1979, Chernobyl USSR 1986, Fukushima Japan 2011] in 35 years are forcing the world’s nuclear industry to stop imagining it can prevent more catastrophes and to focus instead on how to contain them.  As countries such as China and India embrace atomic power even after the Fukushima reactor meltdowns in 2011 caused mass evacuations because of radiation fallout, scientists warn the next nuclear accident is waiting to happen and could be in a country with little experience to deal with it.

“The cold truth is that, no matter what you do on the technological improvements side, accidents will occur — somewhere, someplace,” said Joonhong Ahn, a professor at the Department of Nuclear Engineering of University of California, Berkeley. The consequences of radiation release, contamination and evacuation of people is “clear and obvious,” Ahn said. That means governments and citizens should be prepared, not just nuclear utilities, he said.

While atomic power has fallen from favor in some western European countries since the Fukushima accident — Germany, for example, is shutting all of its nuclear plants — it’s gaining more traction in Asia as an alternative to coal. China has 28 reactors under construction, while Russia, India, and South Korea are building 21 more, according to the World Nuclear Association. Of the 176 reactors planned, 86 are in nations that had no nuclear plants 20 years ago, WNA data show…

The problem is that the causes of the three events followed no pattern, and the inability to immediately contain them escalated the episodes into global disasters with huge economic, environmental and political consequences. Even if no deaths have yet been officially linked to Fukushima radiation, for example, cleanup costs have soared to an estimated $196 billion and could take more than four decades to complete.

If nuclear is to remain a part of the world’s energy supply, the industry must come up with solutions to make sure contamination — and all other consequences — do not spread beyond station grounds, Gregory Jaczko, ex-chairman of the U.S. Nuclear Regulatory Commission, said in an interview in Tokyo….

Since the introduction of nuclear stations in the 1950s, the industry has focused safety efforts on design and planning. Research and innovation has looked at back-up systems, passive technology that would react even if no human operator did, and strengthened materials used in construction of atomic stations….

The official toll from the reactor explosion at Chernobyl was put at 31 deaths. Radiation clean-up work, however, involved about 600,000 people, while 200,000 locals had to be relocated.  The accident contaminated 150,000 kilometers of land and according to the last Soviet leader Mikhail Gorbachev it was a factor in bringing about the collapse of the Soviet Union in 1991.

In Japan, the meltdown of three Fukushima reactors helped unseat premier Naoto Kan and forced the evacuation of about 160,000 people, destroying local fishing, farming and tourism industries along the way. It also brought tens of thousands of anti-nuclear protesters out onto the streets in the country’s biggest demonstrations since the 1960s. Tokyo Electric Power Co., the plant operator and once the world’s biggest non-state power producer, would have been bankrupted by the Fukushima accident but for billions of dollars in government aid…

Building a plant that would contain an accident within the facility boils down to cold cash, he said.  The review calls for new reactor designs to make a major release of radioactive fallout outside the station site “practically impossible,” the IAEA said. The standard would be “crucial for public acceptance and for the sustainability of nuclear energy.” Specialists on the review met for the first time in March and no conclusions are yet available, IAEA spokesman Greg Webb said by e-mail.

The problem with an engineering solution, an ever better reactor design or grander safety systems, is that based on the premise that all technology is fallible those defense systems can also fail, Berkley’s Ahn said.  “This is an endless cycle,” Ahn said. “Whatever is your technology, however it is developed, we always have residual risk.”  When the next nuclear accident occurs the world needs to have better knowledge of how to limit the spread of radiation and do the clean-up, including removing radiation from the soil, water and having an efficient evacuation drill for the population in danger zones, Ahn said. We also need more understanding of the impact of low-dose radiation on organisms, he said.  “This is about recovery from an accident, not preventing an accident,” Ahn said. “It’s completely different. And I think this concept is very necessary for the future of nuclear utilization.”

Excerpts from Yuriy Humber, World Needs to Get Ready for the Next Nuclear Plant Accident, Bloomberg, Apr. 4, 2014

Contaminated Soil, the challenge of cleaning up in Japan


A nuclear decontamination law will go into full effect Sunday Jan. 1, 2012), setting the stage for full-fledged efforts to clean up buildings, soil and waste contaminated with radioactive materials in areas affected by the nuclear crisis at the Fukushima Daiichi power plant in Fukushima Prefecture.  The central government will be responsible for the cleanup efforts in a no-go zone around the crippled plant and other evacuation areas in the seaside prefecture also heavily hit by the March 11 earthquake and tsunami.  Under the law, which was partially enacted in August, decontamination plans will be formulated by 102 municipalities in eight prefectures where radiation doses are expected to exceed 1 millisievert a year on top of natural background radiation and that from medical treatment.  The cleanup cost in the areas will be shouldered by the central government. The eight prefectures are Iwate, Miyagi, Fukushima, Ibaraki, Tochigi, Gunma, Saitama and Chiba.

The Environment Ministry is set to launch an office in the city of Fukushima on Sunday to push decontamination work within Fukushima Prefecture, with plans to start in late January the cleanup of infrastructure such as roads and water supply inside the no-go zone and elsewhere.  Full-fledged cleanup work is likely to start at the end of March, ministry officials said.  The ministry hopes to halve annual radiation doses for ordinary people and reduce those for children by 60 percent by the end of August 2013.

Under the law, the state will dispose of ashes from incinerated waste and sludge if they are found to contain more than 8,000 becquerels of radioactive cesium per kilogram.  It will still be necessary to find either space in the affected areas to temporarily keep contaminated soil and waste or landfills for disposal. The central government has recently asked municipalities in the Futaba district in Fukushima Prefecture to host a temporary storage facility for a massive amount of contaminated soil to be removed within the prefecture.  In the prefectures except Fukushima, contaminated waste is to be buried in landfills with plastic liners, but whether local communities will give a nod to the disposal remains to be seen.

Nuclear decontamination law to go into full force Sunday, Mainichi Daily News, Japan, December 31, 2011

Fukushima Decontamination: lengthy and costly

Japan faces the daunting task of decontaminating large areas of land around the Fukushima Daiichi nuclear complex, which is still leaking low levels of radiation nearly six months after an earthquake and tsunami triggered a nuclear meltdown.  In a meeting with local officials on Saturday, the government estimated it could take more than 20 years before residents could safely return to areas with current radiation readings of 200 millisieverts per year, and a decade for areas at 100 millisieverts per year.  The estimates, which merely confirm what many experts have been saying for months, are based on the natural decline of radiation over time and do not account for the impact of decontamination steps such as removing affected soil….The Japanese government unveiled guidelines this week with the aim of halving radiation in problem areas in two years, but for spots with very high readings it could take much longer to reach safe levels….Japan has banned people from entering within 20 km (12 miles) of the Fukushima plant, located 240 km northeast of Tokyo. Around 80,000 people have been evacuated since the March 11 quake and tsunami and many are living in shelters or temporary homes.

The government’s announcement follows the release of data this week showing radiation readings in 35 spots in the evacuation zone above the 20 millisieverts per year level deemed safe by the government. The highest reading was 508 millisieverts in the town of Okuma, about 3 km from the nuclear plant.  Kan, who resigned on Friday [Aug. 26, 2011] as leader of the ruling Democratic Party of Japan amid intense criticism of his handling of the nuclear crisis, also told Sato that the government planned to build a temporary storage facility in Fukushima for radioactive waste.

The accident at the Fukushima plant is likely to have released about 15 percent of the radiation released at Chernobyl in 1986, Japan’s Nuclear and Industrial Safety Agency has estimated.But that is still more than seven times the amount of radiation produced by Three Mile Island accident in the United States in 1979, and experts have estimated Japan’s decontamination efforts could cost as much as 10 trillion yen ($130 billion).

Osamu Tsukimori and Nathan Layne, Reuters, Aug. 27, 2011

Where it Never Died: Nuclear Power in Russia, Urkraine and Belarus

Twenty-five years after the Chernobyl disaster, Eastern Europe is still clinging to nuclear power. The anti-nuclear movement is essentially non-existent, but experts say ‘green’ energy is still a viable alternative. Don’t panic, it’s really not so bad! This is a sentiment that has been repeated by leading politicians in Russia, Belarus and Ukraine since the start of the crisis at the Fukushima nuclear power plant in Japan. They view this neither as a second Chernobyl, nor as a reason to consider ending the use of nuclear power. In the eyes of Russian President Dmitry Medvedev, for example, nuclear power is “absolutely safe.”

In fact, the Kremlin is planning to more than double the number of nuclear power plants in Russia from the current 10 by 2020. There were even plans to build a nuclear power plant in the Pacific Ocean. However, analysts say that since last month’s powerful earthquake and tsunami, that idea is being revisited and the project may well be cancelled.

Belarus and Ukraine also see nuclear power as the way forward. Ukraine has four nuclear plants and there are plans for a Russian firm to build two more reactors at one of them. The Russian energy firm Rosatom is to begin construction of the first nuclear plant in Belarus in the autumn. Belarusian officials signed the contract on March 15, just days after the nuclear disaster in Japan.  Tobias Münchmeyer, a nuclear expert at Greenpeace in Berlin, believes the difference between Western and Russian nuclear power plants in terms of safety is “much less” than widely believed. According to Münchmeyer, most power plants in Eastern Europe are no less safe than their Western counterparts. But 11 Russian reactors, of the same type involved in the Chernobyl disaster, are an exception. These, Münchmeyer regards as “particularly dangerous.”….

Russian and Ukrainian politicians have repeatedly claimed that there is no alternative to nuclear power. But Münchmeyer disagrees, arguing that Moscow could do away with the use of nuclear power relatively quickly, as it currently accounts for just 17 percent of the electricity produced in Russia. This could be replaced, he said, with power generated by renewable sources or gas.  The situation in Ukraine is quite different. The four nuclear plants there account for 48 percent of the electricity produced in the country. But at the same time, the country produces an excess of power and exports what it doesn’t use itself….

For Russia, Ukraine and Belarus the future is nuclear, Deutsche Welle, Apr. 23, 2011

Official: Fukushima = Chernobyl

Japan raised the crisis level at its crippled nuclear plant Tuesday to a severity on par with the 1986 Chernobyl disaster, citing high overall radiation leaks that have contaminated the air, tap water, vegetables and seawater.  Japanese nuclear regulators said they raised the rating from 5 to 7 — the highest level on an international scale of nuclear accidents overseen by the International Atomic Energy Agency — after new assessments of radiation leaks from the Fukushima Dai-ichi plant since it was disabled by the March 11 tsunami.  The new ranking signifies a “major accident” that includes widespread effects on the environment and health, according to the Vienna-based IAEA. But Japanese officials played down any health effects and stressed that the harm caused by Chernobyl still far outweighs that caused by the Fukushima plant.  The revision came a day after the government added five communities to a list of places people should leave to avoid long-term radiation exposure. A 12-mile (20-kilometer) radius already had been cleared around the plant.  The news was received with chagrin by residents in Iitate, one of the five communities, where high levels of radiation have been detected in the soil. The village of 6,200 people is about 40 kilometers from the Fukushima plant.  “It’s very shocking to me,” said Miyuki Ichisawa, 52, who runs a coffee shop in Iitate. “Now the government is officially telling us this accident is at the same level of Chernobyl.”

Japanese officials said the leaks from the Fukushima plant so far amount to a tenth of the radiation emitted in the Chernobyl disaster, but said they eventually could exceed Chernobyl’s emissions if the crisis continues.  “This reconfirms that this is an extremely major disaster. We are very sorry to the public, people living near the nuclear complex and the international community for causing such a serious accident,” said Chief Cabinet Secretary Yukio Edano…If the leaks continue, the amount of radioactivity released in Fukushima could eventually exceed the amount emitted by Chernobyl, a possibility that Naoki Tsunoda, a TEPCO spokesman, said the company considers “extremely low.”

Excerpt, Yuri Kageyama And Ryan Nakashima, Japan ups nuke crisis severity to match Chernobyl, Associated Press, April 12, 2011