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

UN: 1 Million Somalis at Risk of Hunger

Group warns region is in dire need of humanitarian aid, with at least 200,000 children under age of five acutely malnourished as drought hits southern, central part of nation More

Human Rights Groups Allege Supression of Freedoms in Thailand

Thailand’s military, police have suppressed release of independent report assessing human rights in kingdom during first 100 days of latest coup More

Jennifer Lawrence Contacts FBI After Nude Photos Hacked

'Silver Linings Playbook' actress' photos were posted on image-sharing forum 4chan; Federal Bureau of Investigations is looking into matter 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.
Larger Than Life Chinese Lanterns Make Southern California Appearancei
X
Elizabeth Lee
September 02, 2014 8:57 PM
Chinese lanterns with a long history are lighting up in 21st century style at the Los Angeles County Fair in southern California. Visitors can see traditional lanterns that hang, but also lanterns in the shape of animals, iconic landmarks and many other objects, all created by artisans from a place in China known for its lanterns. Elizabeth Lee has the details from the fair in the city of Pomona.
Video

Video Larger Than Life Chinese Lanterns Make Southern California Appearance

Chinese lanterns with a long history are lighting up in 21st century style at the Los Angeles County Fair in southern California. Visitors can see traditional lanterns that hang, but also lanterns in the shape of animals, iconic landmarks and many other objects, all created by artisans from a place in China known for its lanterns. Elizabeth Lee has the details from the fair in the city of Pomona.
Video

Video Experts See Rise of ISIS as Significant Development

The Islamic State’s rise seems sudden. It caught the U.S. by surprise this summer when it captured large portions of northern Iraq and spread its wings in neighboring Syria. But many analysts contend that the group - which grew out of al-Qaida in Iraq - has been rebuilding for years. VOA's Jela de Franceschi takes a closer look at the rise of ISIS and its implications for the Middle East and beyond.
Video

Video Israel Concerned Over Syrian Rebels in Golan

Israeli officials are following with concern the recent fighting between Syrian rebels and government forces near the contested Golan Heights. Forty-four U.N. peacekeepers from Fiji have been seized by Syrian Islamist rebels and the clashes occasionally have spilled into Israel. VOA’s Scott Bobb reports from Jerusalem.
Video

Video Ukraine Schools Resume Classes, Donate to Government Forces

A new school year has started in Ukraine but thousands of children in the war-torn east are unable to attend because of ongoing clashes with pro-Russia rebels. In Ukraine's capital, patriotic education has become the norm along with donations to support injured security forces fighting to take back rebel-held areas. VOA's Daniel Schearf reports from Kyiv.
Video

Video US Detainees Want Negotiators for Freedom in North Korea

The three U.S. detainees held in North Korea were permitted to speak with foreign media Monday. The government of Kim Jong Un restricted the topics of the questions, and the interviews in Pyongyang were limited to five minutes. Each of the men asked Washington to send a representative to Pyongyang to secure his release. VOA’s Carolyn Presutti has our story.
Video

Video Turkmen From Amerli Describe Survival of IS Siege

Over the past few weeks, hundreds of Shi'ite Turkmen have fled the town of Amerli seeking refuge in the northern city of Kirkuk. Despite recent military gains after U.S. airstrikes that were coordinated with Iraqi and Kurdish forces, the situation remains dire for Amerli’s residents. Sebastian Meyer went to Kirkuk for VOA to speak to those who managed to escape.
Video

Video West Africa Ebola Vaccine Trials Possible by Early 2015

A U.S. health agency is speeding up clinical trials of a possible vaccine against the deadly Ebola virus that so far has killed more than 1,500 people in West Africa. If successful, the next step would be a larger trial in countries where the outbreak is occurring. VOA's Carol Pearson has more.
Video

Video Survivors Commemorate 70th Anniversary of Nazi Liquidation of Jewish Ghetto

When the German Nazi army occupied the Polish city of Lodz in 1939, it marked the beginning of a long nightmare for the Jewish community that once made up one third of the population. Roughly 200,000 people were forced into the Lodz Ghetto. Less than 7,000 survived. As VOA’s Kane Farabaugh reports, some survivors gathered at the Union League Club in Chicago on the 70th anniversary of the liquidation of the Lodz Ghetto to remember those who suffered at the hands of the Nazi regime.

AppleAndroid