Nuclear Threat Remains After Japan Quake

There’s been more trouble at Japan’s stricken Fukushima nuclear power plant. With cooling systems down, fuel rods have been exposed at the facility’s Unit 2 reactor, and there was an explosion at Unit 3.

While not ideal these explosions keep the threat of a total nuclear meltdown to a minimum. And that’s the best Japanese officials can do after last Friday’s monster earthquake and tsunami.

Japan has about 50 nuclear power plants scattered throughout Honshu island. The 8.9 earthquake that struck on March 11 was centered offshore from the north portion of the island. Sendai city was one of the hardest hit areas. That town is near the Fukushima nuclear power plant, where a loss of power and access to freshwater has crippled operations there.

All power plants automatically shutdown when there is an earthquake in Japan. It’s a precaution to prevent a nuclear disaster. But several plants failed to cool down properly after the big earthquake and tsunami. An explosion forced a 12-mile evacuation and scared residents around the world on Saturday. Then another blast at a different unit at the same power plant on Monday raised concern again.

Japanese officials explained that they are being forced to push seawater into the reactor to cool the nuclear fuel rods. The corrosive saltwater destroys the power plant, costing about $1 billion. But if successful it prevents a much greater threat–a total nuclear meltdown.

The two blasts occurred when hydrogen inside the reactor core built up enough heat and pressure which needed to be released. Venting that heat along with a small amount of radioactive cesium particles caused the cement structure housing the containment units to explode. But the containment units, inside which sit the nuclear reactor cores, appear to be intact. This greatly reduces the threat of radiation escaping the facility and causing more damage.

160 people are being treated for low level exposure to radiation while some media over the weekend reported that iodine tablets were being distributed as a precaution.

When situations like this arise, scientists begin looking at all possible scenarios. One such outcome is a meltdown of the nuclear core, which causes a critical nuclear event, including emission of radioactive material. If that were to happen the release could threaten a lot more people.

Nuclear experts and atmospheric scientists in the U.S. started speculating as soon as explosions at nuclear power plants were broadcast over the weekend.

Dan Jaffe, an atmospheric chemist at the University of Washington says it is very unlikely that the amount of radiation released in Japan would make it to the west coast of the United States.

A few scientists in Seattle have documented pollution crossing the Pacific Ocean and reaching the west coast. In 1998, Dr. Jaffee noted that atmospheric ozone from China was able to travel to the U.S. under the right conditions in about a week. That surge of pollution was enough to push ozone levels in the Northwest past limits set by the Environmental Protection Agency.

Dr. Jaffe says, “If the nuclear incidents turn into a major meltdown and release radiation, and depending on wind patterns, it could be transported in about seven days.”

But that’s a big if.

Japan is perhaps the nation best equipped to handle a triple-whammy threat of earthquake, tsunami and nuclear accident. Even though this is being described as the most devastating event since World War II and the most threatening earthquake and tsunami in 1,200 years, Japanese officials are trying to prevent the worst case scenario by sacrificing nuclear power plants in order to spare the rods in the reactors and prevent a bigger disaster.

Dr. Jaffe says that he and his team have established an atmospheric observatory on Mt. Bachelor in the mountains of Oregon. While the sensors are designed to monitor pollution traveling from Asia, he says in the event of a major radiation release he would try to get some detectors added to the observatory to track the path of the radiation.