News / Asia

IAEA: No Indication of Nuclear Reactor Meltdown in Japan

Fukushima Daiichi power plant's Unit 1 is seen in Okumamachi, Fukushima prefecture, Japan, Friday, March 11, 2011
Fukushima Daiichi power plant's Unit 1 is seen in Okumamachi, Fukushima prefecture, Japan, Friday, March 11, 2011

The head of the International Atomic Energy Agency, or IAEA, said Monday in Vienna that despite problems at two nuclear power plants in Japan stemming from last week's earthquake and tsunami, there is no indication of a reactor meltdown.  But the fluid situation and fears of a possible meltdown are raising concerns.

IAEA Director General Yukiya Amano sought to calm fears about the release of radioactive gas into the air, following two explosions at the Fukushima nuclear power plant, some 200 kilometers north of Tokyo. "Despite the hydrogen explosions, reactors vessels and containment vessels stayed in tact.  As a result, the release of radioactivity was limited," he said.

Amano described the many layers of protection at the Japanese plant. "The nuclear reactors BWR [i.e., boiling water reactor] have multiple safety measures. The nuclear core is contained in reactor vessels that are made of higher [grade] steel.  Then the reactor's vessel is contained in a primary containment vessel that is made of concrete," he said.

Japan expert Daniel Aldrich of Purdue University in the U.S. state of Indiana says the situation at the stricken plant is not as serious as the 1986 nuclear power accident at Chernobyl in what is now Ukraine. "This is a smaller scale meltdown, where the fuel rods themselves have not been cooled down by water or normally by other cooling fluids.  So in this case, it means the fuel gets so hot, the rods themselves melt.  And if uncontrolled, this could build into a larger meltdown.  So right now, to our knowledge, this is only a partial meltdown," he said.

But nuclear engineer David Lochbaum with the Union of Concerned Scientists cautions that it is difficult to detect a meltdown.  "There's not an annunciator; there's not an alarm window or a computer print out that says, 'I've experienced a core meltdown.'"

A partial core meltdown occurs when nuclear fuel is not cooled for several hours and begins to melt.  A full nuclear meltdown occurs when the fuel in the core melts and falls to the bottom of the reactor's containment vessel.  If the heat ruptures the vessel, it could result a large and violent release of radiation with serious health effects.

Expert Daniel Aldrich says that so far, the release of radiation at the Fukushima plant has been similar to the 1979 accident at Three Mile Island in the United States rather than the Chernobyl disaster, the worst nuclear accident in history.

"Well we know from Chernobyl, it was a tremendously large, full meltdown, we had there in Russia.  It's possible for radioactivity to travel literally thousands of miles in the atmosphere.  From Three Mile Island though, which I think is a better to comparison to what's going on now, the maximum distance we think it traveled was just a few miles.  In fact, Three Mile Island never had provable health effects on local residents there," he said.

But physicist Edwin Lyman with the Union of Concerned Scientists says the radiation exposure levels of three U.S. helicopters crews flying far from the Fukushima plant, should be cause for concern.  "I think it's not a surprise that there would be a propagation of some fission products as far as 100 miles [from the plant], but what  is surprising is the extent of the dose rate that I heard was attributed to the airman, which seems to be a little bit higher than I would have been expected at this point," he said.

About 200,000 people have been evacuated from areas around Fukushima and other troubled nuclear power stations.  About 600 people still in homes near the Fukushima plant have been advised to remain indoors.

You May Like

Scotland Vote Raises Questions of International Law

Experts say self-determination, as defined and protected by international law, confined narrowly to independence movements in process of de-colonization More

Video Whaling Summit Votes to Uphold Ban on Japan Whale Hunt

Conservationists hail ruling as a victory, but Tokyo says it will submit revised plans for a whale hunt in 2015 More

Annual Military Exercise Takes on New Meaning for Ukraine Troops

Troops from 15 nations participating in annual event, 'Rapid Trident' in western Ukraine More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Russian Economy Reeling After New Western Sanctionsi
X
September 18, 2014 2:28 AM
A new wave of Western sanctions is hitting Russia’s economy hard. State-owned energy firms continue to bleed profits and Russia’s national currency plunged to a new low this week after the U.S. and the European Union announced new sanctions to punish Russia's aggressive stance in eastern Ukraine. But as Mil Arcega reports, the sanctions could also prove costly for European and American companies.
Video

Video Russian Economy Reeling After New Western Sanctions

A new wave of Western sanctions is hitting Russia’s economy hard. State-owned energy firms continue to bleed profits and Russia’s national currency plunged to a new low this week after the U.S. and the European Union announced new sanctions to punish Russia's aggressive stance in eastern Ukraine. But as Mil Arcega reports, the sanctions could also prove costly for European and American companies.
Video

Video Belgian Researchers Discover Way to Block Cancer Metastasis

Cancer remains one of the deadliest diseases, despite many new methods to combat it. Modern medicine has treatments to prevent the growth of primary tumor cells. But most cancer deaths are caused by metastasis, the stage when primary tumor cells change and move to other parts of the body. A team of Belgian scientists says it has found a way to prevent that process. Zlatica Hoke has more.
Video

Video Mogadishu's Flood of Foreign Workers Leaves Somalis Out of Work

Unemployment and conflict has forced many young Somalians out of the country in search of a better life. But a newfound stability in the once-lawless nation has created hope — and jobs — which, some say, are too often being filled by foreigners. Abdulaziz Billow reports from Mogadishu.
Video

Video A Dinosaur Fit for Land and Water

Residents and tourists in Washington D.C. can now examine a life-size replica of an unusual dinosaur that lived almost a hundred million years ago in northern Africa. Scientists say studying the behemoth named Spinosaurus helps them better understand how some prehistoric animals adapted to life on land and in water. The Spinosaurus replica is on display at the National Geographic museum. VOA’s George Putic has more.
Video

Video Iraqi Kurdistan Church Helps Christian Children Cope find shelter in churches in the Kurdish capital, Irbil

In the past six weeks, tens of thousands of Iraqi Christians have been forced to flee their homes by Islamic State militants and find shelter in churches in the Kurdish capital, Irbil. Despite U.S. airstrikes in the region, the prospect of people returning home is still very low and concerns are starting to grow over the impact this is having on the displaced youth. Sebastian Meyer reports from Irbil on how one church is coping.
Video

Video NASA Picks Boeing, SpaceX to Carry Astronauts Into Space

The U.S. space agency, NASA, has chosen Boeing and SpaceX companies to build the next generation of spacecraft that will carry U.S. astronauts to the International Space Station by the year 2017. The deal with private industry enables NASA to end its dependence on Russia to send space crews into low Earth orbit and back. Zlatica Hoke has more.
Video

Video Future of Ukrainian Former President's Estate Uncertain

More than six months after Ukraine's former President Viktor Yanukovych fled revolution to Russia, authorities have yet to gain control of his palatial estate. Protesters occupy the grounds and opened it to tourists but they are also refusing to turn it over to the state. VOA's Daniel Schearf reports from Mezhigirya, just north of Kyiv.
Video

Video China Muslims Work to Change Perceptions After Knife Attacks

China says its has sentenced three men to death and one woman to life in prison for a deadly knife attack in March that left more than 30 dead and 140 injured. Beijing says Muslim militants from China's restive western region of Xinjiang carried out the attacks. Now, more than six months after the incident, residents in the city are still coping with the aftermath. VOA's Bill Ide has more from Kunming.


Carnage and mayhem are part of daily life in northern Nigeria, the result of a terror campaign by the Islamist group Boko Haram. Fears are growing that Nigeria’s government may not know how to counter it, and may be making things worse. More

AppleAndroid