OREGON STATE UNIVERSITY

For now, damaged Japanese nuclear plants pose no risk to U.S.

03/14/2011

Editor’s Note: As of Friday, March 18, the situation with damaged reactors in Japan is gradually improving. Power is being installed, radiation levels are dropping and containment facilities are intact in several of the reactors. There appear to be no life threatening issues at the moment and the crisis is being managed more effectively, according to experts in the OSU Department of Nuclear Engineering and Radiation Health Physics. This situation is becoming more stabilized and the threat of additional releases of radioactive material is being reduced. Based on current atmospheric conditions, any radioactive materials released would probably travel at low levels, first toward the Aleutian Islands and Alaska, then southeast toward Canada and the West Coast of the United States. Experts in the Department of Nuclear Engineering and Radiation Health Physics at OSU say there is still no concern about health impacts beyond the immediate area in Japan. They say that even in a “worst case” scenario of more catastrophic failure of containment systems, the long distance from Japan – more than 4000 miles – along with dilution in the atmosphere and ocean, will largely eliminate any health concerns in the United States. This accident is considerably more of a concern than the Three Mile Island incident decades ago in the U.S. but still less than the Chernobyl accident in the Ukraine, still considered the most serious nuclear incident in history. Additional information will be released by OSU News and Research Communications if this evaluation changes significantly. News media representatives may feel free to contact OSU experts in the Department of Nuclear Engineering and Radiation Health Physics for the latest updates on this issue as it evolves.

 

CORVALLIS, Ore. – Although the situation with damaged nuclear reactors in Japan is still uncertain, every hour without further incidents is good news, according to nuclear energy experts at Oregon State University – and in any case, the events pose virtually no risk to people in the United States or Canada.

The nature of the incident may be similar to that of Three Mile Island in the U.S in 1979, said experts in reactor operation and radiation health physics, in which there were some minor releases of radiation but the containment system ultimately worked and minimized impacts.

No radioactive contaminants from this incident have been recorded in the U.S. and none are expected, said Kathryn Higley, professor and director of the OSU Department of Nuclear Engineering and Radiation Health Physics.

“As things look at the moment, whatever impact there is from this event will almost certainly be very local,” Higley said. “Any radioactive contaminants released will end up raining out of the atmosphere into the Pacific Ocean, where they will be diluted and absorbed, or in the near vicinity of the plants.

“We have monitoring capability here in the U.S. that is extraordinarily sensitive and could detect radiation at the level of about 1/100,000 of that produced by an ordinary X-ray, and we don’t expect to see even that,” she said. “This is not Chernobyl.”

At that more serious radioactive accident in 1986 in the Ukraine, considered the worst nuclear reactor accident in history, a great deal of heat and energy was released in explosions that sent radioactive materials high into the atmosphere and had impacts on much of Europe. The events in Japan bear little relationship to that, OSU experts say.

“There has been a hydrogen explosion and some people were hurt,” Higley said. “However, the containment vessels are still intact, made out of very thick steel and concrete, and so far there have been only minor releases of some radioactive iodine and cesium.”

According to Steven Reese, director of the Radiation Center at OSU, any radioactive elements released should follow normal atmospheric patterns and fall with rain into the Pacific Ocean. The iodine and cesium will actually combine with the salt in sea water – salt is sodium chloride - to turn into sodium iodide and cesium chloride, which are common and abundant elements and would readily dilute in the wide expanse of the Pacific Ocean.

Another immediate public concern, the OSU experts said, is the loss of electrical power in Japan at a time when than nation critically needs it. The nuclear power plants that are out of operation supply nearly 4 percent of Japan’s power production, they said, and loss of that energy capacity is a serious concern, especially during winter, as the nation struggles to care for displaced residents. Rolling blackouts will be occurring shortly and Japanese citizens are being urged to minimize electricity usage.

More details will be known about the nature of the accident with the Japanese power plants in coming days, but no scenario is likely to pose any risks to U.S. residents, the OSU experts said.