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

How to Safeguard Your Mobile Privacy

As the digital world becomes more mobile, so too do concerns about eroding privacy and increased hacking More

'Desert Dancer' Chronicles Iranian Underground Dance Troupe

Film by Richard Raymond is based on true story of Afshin Ghaffarian and his friends More

Obesity Poses Complex Problem

Professor warns of obesity’s worldwide health impact 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.
Rolling Thunder Run Reveals Changed Attitudes Towards Vietnam Wari
X
Katherine Gypson
May 25, 2015 1:32 AM
For many US war veterans, the Memorial Day holiday is an opportunity to look back at a divisive conflict in the nation’s history and to remember those who did not make it home.
Video

Video Rolling Thunder Run Reveals Changed Attitudes Towards Vietnam War

For many US war veterans, the Memorial Day holiday is an opportunity to look back at a divisive conflict in the nation’s history and to remember those who did not make it home.
Video

Video Female American Soldiers: Healing Through Filmmaking

According to the United States Defense Department, there are more than 200-thousand women serving in the U.S. Armed Forces.  Like their male counterparts, females have experiences that can be very traumatic.  VOA's Bernard Shusman tells us about a program that is helping some American women in the military heal through filmmaking.
Video

Video Iowa Family's Sacrifice Shaped US Military Service for Generations

Few places in America have experienced war like Waterloo. This small town in the Midwest state of Iowa became famous during World War II not for what it accomplished, but what it lost. As VOA’s Kane Farabaugh reports, the legacy of one family’s sacrifice is still a reminder today of the real cost of war for all families on the homefront.
Video

Video On Film: How Dance Defies Iran's Political Oppression

'Desert Dancer' by filmmaker Richard Raymond is based on the true story of a group of young Iranians, who form an underground dance troupe in the Islamic Republic of Iran. This is the latest in a genre of films that focus on dance as a form of freedom of expression against political oppression and social injustice. VOA’s Penelope Poulou has more.
Video

Video Turkey's Ruling Party Trying to Lure Voters in Opposition Stronghold

Turkey’s AK (Justice and Development) Party is seeking a fourth successive general election victory, with the goal of securing two-thirds of the seats in Parliament to rewrite the constitution and change the country's parliamentary system into a presidential one. To achieve that, the party will need to win seats in opposition strongholds like the western city of Izmir. Dorian Jones reports.
Video

Video Millions Flock to Ethiopia Polls

Millions of Ethiopians cast their votes Sunday in the first national election since the 2012 death of longtime leader Meles Zenawi. Mr. Meles' party, the Ethiopian People's Revolutionary Democratic Front, is almost certain of victory again. VOA's Anita Powell reports from Addis Ababa.
Video

Video Scientists Testing Space Propulsion by Light

Can the sun - the heart of our solar system - power a spacecraft to the edge of our solar system? The answer may come from a just-launched small satellite designed to test the efficiency of solar sail propulsion. Once deployed, its large sail will catch the so-called solar wind and slowly reach what scientists hope to be substantial speed. VOA’s George Putic reports.
Video

Video FIFA Trains Somali Referees

As stability returns to the once lawless nation of Somalia, the world football governing body, FIFA, is helping to rebuild the country’s sport sector by training referees as well as its young footballers. Abdulaziz Billow has more from Mogadishu.
Video

Video With US Child Obesity Rates on the Rise, Program Promotes Health Eating

In its fifth year, FoodCorps puts more than 180 young Americans into 500 schools across the United States, where they focus on teaching students about nutrition, engaging them with hands-on activities, and improving their access to healthy foods whether in the cafeteria or the greater community. Aru Pande has more.
Video

Video Virginia Neighborhood Draws People to Nostalgic Main Street

In the U.S., people used to grow up in small towns with a main street lined by family-owned shops and restaurants. Today, however, many main streets are worn down and empty because shoppers have been lured away by shopping malls. But in the Del Ray neighborhood of Alexandria, Virginia, main street is thriving. VOA’s Deborah Block reports it has a nostalgic feel with its small restaurants and unique stores.

VOA Blogs