News / Asia

US Nuclear Experts Worry About Possible Japan Reactor Meltdown

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
Mike O'Sullivan

Tens of thousands of residents near a nuclear plant in Japan were evacuated Saturday after an explosion at the plant, 240 kilometers north of Tokyo.  The reactor failure follows a devastating earthquake and tsunami that struck northeastern Japan on Friday.

Japanese officials have reassured the public, saying there is no danger of a meltdown of the reactor core. But US nuclear experts say they are worried about the possibility.

The failure at the plant in Fukushima Prefecture was caused by a power loss, and then a loss of backup power, following the massive earthquake and tsunami Friday.

A Japanese official said a buildup of hydrogen in the reactor's cooling system caused the explosion, but he said the containment structure was intact.  Radiation was released, but government officials say the levels were low and are dropping.

Watch the explosion at reactor number one in Fukushima

Saturday, residents within 20 kilometers of the plant were evacuated, while government officials said there is no danger of a melt-down and large-scale radiation release, like the one at Chernobyl, Ukraine, in 1986 that sent radioactive clouds billowing across Europe.

The four American experts and a colleague in Japan briefed reporters by telephone Saturday, and they said  they were less certain.  

Nuclear energy analyst Robert Alvarez of the Institute for Policy Studies says there are many things we do not know about the failure, including whether the containment structure is fully intact. "The information that has been made public, particularly by the Japanese nuclear safety authorities, certainly indicate that radioactive elements from the fuel itself have escaped and entered the environment.  And even if the reactor maintains its integrity, there's a possibility that things like open relief valves on the top of the reactor and things like that may still release large amounts of radioactivity," he said.

Ken Bergeron, a physicist who formerly worked for Sandia National Laboratories, says a so-called station blackout - which involves the loss of both off-site electricity and on-site backup power from diesel generators - is viewed in the nuclear industry as extremely unlikely.  But he says it happened.

"So we're in uncharted territory.  We're in the land where probability says we shouldn't be.  And we're hoping that all of the barriers to release of radioactivity will not fail," he said.

He said the first barrier, the so-called fuel cladding that covers the reactor rods, has apparently failed, which he says is shown by the release of radiation into the atmosphere.  

Crews are pumping a mixture of seawater and boron to cool the reactor, and these experts say it is essential to keep the water flowing for several days.  Analyst Alvarez called the use of seawater a "Hail Mary pass", a term from American football meaning an act of desperation.  But he said that with enough water pumped at sufficient volume and rate, the reactor can be stabilized.

Ken Bergeron said it is also crucial to restore electric power in order to pump enough water.

Ira Helfand of the group Physicians for Social Responsibility says the reactor contains huge levels of  radioactivity that cannot be allowed to escape. "The bottom line is that we just don't know what's going to happen over the next couple of days. And frankly, neither do the people who are operating these power plants.  They're very complex systems that are clearly way out of whack, and whether they're going to be able to contain the radiation inside the reactors or not, is simply not known at this point," he said.

Japanese health officials have announced they will distribute iodine tablets as a precaution.  Iodine is know to protect against radiation-induced thyroid cancer.

You May Like

US, China Have Dueling Definitions of Cybersecurity

Analysts say attribution or or proving that a particular individual or government is responsible for a hack, is a daunting task More

Snowden: I'd Go to Prison to Return to US

Former NSA contractor says he has not received a formal plea-deal offer from US officials, who consider him to be a traitor More

Goodbye Pocahontas: Photos Reveal Today's Real Native Americans

Weary of stereotypes, photographer Matika Wilbur is determined to reshape the public's perception of her people More

This forum has been closed.
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.
Russia’s Syria Involvement Raising Concerns in Europei
Luis Ramirez
October 02, 2015 4:45 PM
European nations are joining the United States in demanding that Russia stop targeting opposition groups other than the Islamic State militants as Russian warplanes continue to conduct raids in Syria. The demand came in a statement from Britain, France, Germany, Qatar, Saudi Arabia, Turkey and the United States Friday. VOA Europe correspondent Luis Ramirez reports.

Video Russia’s Syria Involvement Raising Concerns in Europe

European nations are joining the United States in demanding that Russia stop targeting opposition groups other than the Islamic State militants as Russian warplanes continue to conduct raids in Syria. The demand came in a statement from Britain, France, Germany, Qatar, Saudi Arabia, Turkey and the United States Friday. VOA Europe correspondent Luis Ramirez reports.

Video First Self-Driving Truck Debuts on European Highways

The first automated semi-trailer truck started its maiden voyage Friday, Oct. 2, on a European highway. The Daimler truck called 'Actros' is the first potentially mass-produced truck whose driver will be required only to monitor the situation, similar to the role of an airline captain while the plane is in autopilot mode. VOA’s George Putic reports.

Video Nano-tech Filter Cleans Dirty Water

Access to clean water is a problem for hundreds of millions of people around the world. Now, a scientist and chemical engineer in Tanzania (in East Africa) is working to change that by creating an innovative water filter that makes dirty water safe. VOA’s Deborah Block has the story.

Video Demand Rising for Organic Produce in Cambodia

In Cambodia, where rice has long been the main cash crop, farmers are being encouraged to turn to vegetables to satisfy the growing demand for locally produced organic farm products. Daniel de Carteret has more from Phnom Penh.

Video Migrant Influx Costs Europe, But Economy Could Benefit

The influx of hundreds of thousands of refugees and migrants is testing Europe’s ability to respond – especially in the poorer Balkan states. But some analysts argue that Europe will benefit by welcoming the huge numbers of young people – many of them well educated and willing to work. Henry Ridgwell reports from London.

Video Botanists Grow Furniture, with Pruning Shears

For something a bit out of the ordinary to furnish your home, why not consider wooden chairs, crafted by nature, with a little help from some British botanists with an eye for design. VOA’s Jessica Berman reports.

Video New Fabric Helps Fight Dust-Related Allergies

Many people around the world suffer from dust-related allergies, caused mainly by tiny mites that live in bed linen. Polish scientists report they have successfully tested a fabric that is impenetrable to the microscopic creatures. VOA’s George Putic has more.

Video Burkina Faso's Economy Deeply Affected by Political Turmoil

Political turmoil in Burkina Faso over the past year has taken a toll on the economy. The transitional government is reporting nearly $70 million in losses in the ten days that followed a short-lived coup by members of the presidential guard earlier this month. The crisis shut businesses and workers went on strike. With elections on the horizon, Emilie Iob reports on what a return to political stability can do for the country's economic recovery.

Video Fleeing Violence, Some Syrians Find Refuge in Irbil

As Syrians continue to flee their country’s unrest to seek new lives in safer places, VOA Persian Service reporter Shepol Abbassi visited Irbil, where a number Syrians have taken refuge. During the religious holidy of Eid al-Adha, the city largely shut down, as temperatures soared. Amy Katz narrates his report.

Video Nigeria’s Wecyclers Work for Reusable Future in Lagos

The streets and lagoons of Africa's largest city - Lagos, Nigeria - are often clogged with trash, almost none of which gets recycled. One company is trying to change that. Chris Stein reports for VOA from Lagos.

Video Sketch Artist Helps Catch Criminals, Gives a Face to Deceased

Police often face the problem of trying to find a crime suspect based on general descriptions that could fit hundreds of people in the vicinity of the crime. In these cases, an artist can use information from witnesses to sketch a likeness that police can show the public via newspapers and television. But, as VOA’s Greg Flakus reports from Houston, such sketches can also help bring back faces of the dead.

Video Thailand Set to Build China-like Internet Firewall

Thai authorities are planning to tighten control over the Internet, creating a single international access point so they can better monitor content. VOA Correspondent Steve Herman reports from Bangkok on what is being called Thailand’s own "Great Firewall."

Video Croatian Town’s War History Evokes Empathy for Migrants

As thousands of Afghanistan, Iraqi and Syrian migrants pass through Croatia, locals are reminded of their own experiences with war and refugees in the 1990s. VOA's Daniel Schearf reports from the town of Vukovar, where wartime scars still are visible today.

Video Long Drought Affecting California’s Sequoias

California is suffering under a historic four-year drought and scientists say even the state's famed sequoia trees are feeling the pain. The National Park Service has started detailed research to see how it can help the oldest living things on earth survive. VOA’s George Putic reports.

VOA Blogs