MANILA, Philippines—It’s a big ocean between northeastern Japan and the Philippines or the United States and thousands of kilometers from the crippled nuclear power plant to much of Asia.
That means there’s little chance—at least for now—that radiation from the shattered reactors in Japan could pose a serious threat to the wider world, according to scientists.
They said the amount of radioactivity emitted by the facility was relatively minor and should dissipate quickly over the Pacific Ocean.
“Every mile of ocean it crosses, the more it disperses,” said Peter Caracappa, a radiation safety officer and clinical assistant professor of nuclear engineering at Rensselaer Polytechnic Institute in Troy, New York.
Corazon Bernido, deputy director of the Philippine Nuclear Research Institute (PNRI), also said the amount of radioactivity diminished with distance.
Bernido likened it to dropping ink into water. “It’s the same with radioactivity. When it becomes diluted and disperses, it reaches normal levels,” she said.
Asked if the worst-case scenario happened in Japan and the wind direction headed toward the Philippines, she said the effect would not be catastrophic.
“If the wind will reach us, the dispersion will dilute [radioactivity] and I don’t think it will be that bad,” she said.
Sticks to buildings
The areas to be affected will depend on which way the wind is going, she added.
So far, the radiation released in Japan has not reached high altitudes, said Kathryn Higley, director of the Oregon State University Department of Nuclear Engineering and Radiation Health Physics.
“In addition, radioactive material is sticky. It has a static charge,” she said, so it will stick to the sides of buildings, and “rain is going to knock it down.”
As a precaution, the World Meteorological Organization has activated specialized weather centers to monitor the situation. Those centers, in Beijing, Tokyo and Obninsk, Russia, will track any contaminants.
Director Cesario Pagdilao of the Philippine Council for Aquatic and Marine Research and Development said there was no reason to worry that marine life would be affected by radiation.
Pagdilao said radiation from the Fukushima Dai-ichi nuclear plant was in the atmosphere and if it would hit water, it would be diluted.
Chernobyl scenario
Bernido said the Dai-ichi nuclear plant was unlikely to deteriorate into something like what happened to Chernobyl, the nuclear plant in the Ukraine that exploded and spread radioactive clouds in 1986.
“It will never be like the Chernobyl accident because the design [of the plant] is different. Chernobyl had no containment, but this has many layers to prevent the spread of radiation,” Bernido told reporters.
US experts earlier voiced concerns that Japan could experience a Chernobyl-like disaster. The Dai-ichi nuclear plant was badly affected by the 9-magnitude earthquake and ensuing tsunami that hit Japan on March 11.
The PNRI, in its bulletin issued Wednesday, said that despite the fire that hit the nuclear power plant’s spent fuel storage facility and another explosion at a third reactor, there was no threat to the Philippines, which is about 3,000 kilometers from Japan.
No immediate threat
“Any significant effect is limited only within the power station boundary and immediate vicinity,” it said. “The DOST-PNRI emphasizes that there remains no immediate threat to the Philippines.”
As of 9 a.m. on Wednesday, the radiation level in the country was 89 to 120 nanoSievert per hour.
The general public can be safely exposed to up to one milliSievert (mSv) per year, while workers in the nuclear industry can receive within safe limits of up to 20 times the amount. This is on top of the background radiation that people get from the environment.
X-ray scan
An X-ray scan’s radiation level is 0.2 mSv, according to Bernido. But she said exposure to 250 mSv had no obvious effect.
The PNRI said that the radiation level at the Dai-ichi plant’s main gate was 0.6 mSv.
Secretary Mario Montejo of the Department of Science and Technology said that what would be a cause of worry was if a total meltdown occurred and if the spent fuel pools lost water.
But Montejo said the situation was far from happening.
He said the PNRI bulletin noted that the vessels of the No. 1, No. 2 and No. 3 reactors and the containments vessels for No. 1 and No. 3 reactors in the Fukushima Dai-ichi plant remained intact.
Containment unit intact
While the suppression chamber of the No. 2 reactor was damaged, the rest of the containment unit was intact, he said.
Bernido said that one of the layers of the Dai-ichi plant was ceramic and could melt only at very high temperatures. There is also a Zircaloy layer that would only melt at 1,000 degrees Celsius. There is also a steel vessel that is four to eight inches thick, and another concrete container.
The PNRI said there were no indications that spent fuel assemblies in the storage ponds of all units had been exposed. The condition of the cooling systems in three reactors, Nos. 1, 2 and 3, while “not normal” was under control, it added.
Wind direction
The PNRI also said that based on wind direction, any radiation from the plant was moving toward the east and away from the Philippines.
“This would mean that winds which may carry any radioactive materials from the affected nuclear plant will not affect any part of the Philippines. The same wind patterns are predicted for the next three days,” it said.
Precautions taken
Vicente Malano, a deputy director of the Philippine Atmospheric, Geophysical and Astronomical Services Administration, said the chance that the wind direction would change was remote, based on historical data.
Experts say that in terms of public health, the Japanese have already taken precautions that should prevent the accident from becoming another Chernobyl, even if additional radiation is released.
The Japanese government has evacuated people closest to the plant, told others to stay indoors and distributed the drug potassium iodide to protect the thyroid gland from radioactive iodine.
The great tragedy of Chernobyl was an epidemic of thyroid cancer among people exposed to the radiation as children—more than 6,000 cases so far, with more expected for many years to come. There is no reason for it to be repeated in Japan.
Milk
The epidemic in Chernobyl was preventable and would probably not have happened if people had been told to stop drinking locally produced milk, which was by far the most important source of radiation. Cows ate grass contaminated by fallout from the reactors and secreted radioactive iodine in their milk. Reports from Leila B. Salaverria, Associated Press and New York Times News Service