Nuclear expert says 50/50 odds of catastrophic radiation from Japan

Nuclear expert Arnie Gundersen warns that the unfolding nuclear disaster in Japan may result in a catastrophic radiation release that will reach American shores.

Gundersen, a nuclear engineer with 39 years of experience and chief engineer with Fairewinds Associates, told the Global Post that he doesn’t have much faith in official pronouncements about the scale of the disaster.

Here are some experts:

GlobalPost: Officials have said the possibility of a large-scale radiation release is small. Do you agree?

Arnold Gundersen: I think that the probability of a large scale release is about 50-50, and I don’t call that small.

GlobalPost: Why do you think that?

Gundersen: For several reasons. One, you’ve got three reactors involved. Two, you’re already picking up radiation on aircraft carriers a hundred miles away at sea, on helicopters 60 miles to the north, and in town. So clearly, as these plants become more and more difficult to control, it becomes quite likely that a containment now will have a gross failure. And a gross failure will release enormous amounts of radiation quickly.

GlobalPost: The New York Times is reporting that radioactive releases could go on for weeks or months. How concerned should we be about that? At what point does a reactor like this becomes less menacing?

Gundersen: The chain reaction has stopped. That happened in two seconds. But the radioactive isotopes are still decaying away. They’ll decay for at least a year. So you have to release the pressure from that containment pretty much every day. With releasing the pressure will come releasing radioactive isotopes as well.

So yes, the Times is right that every plant ­ there are now three or four of them ­ will be opening up valves every day to make sure the pressure is down. And there will be releases from these plants for at least a year.

GlobalPost: How much of a health threat is that?

Gundersen: Within 90 days, the iodine health risks will disappear, because that will decay away. But the nasty isotopes ­ the cesium and strontium will remain for 30 years. And they’re volatile.

After Three Mile Island, strontium was detected 150 miles away from the reactor. That ends up in cow’s milk and doesn’t go away for 300 years. The releases from these plants will last for a year, and will contain elements that will remain in the environment for 300 years, even in the best case.

If we have a meltdown, it will be even worse than that.

Gundersen told the GlobalPost that the steel containment vessels around the reactors are only about an inch thick and are leaking, as evidenced by the presence of iodine and cesium around the plant.

I can’t understand how officials can say that the releases are low, when they don’t have any instruments that are working. Their batteries have failed, and when the batteries fail, all of the instruments stop working. So it’s hard to determine what the radiation levels are, and what the pressure levels are.

The Japanese and the nuclear industry are heavily, heavily financially invested in this. My experience is that, after Three Mile Island and after Chernobyl, everybody said there wasn’t a problem, until there was a problem. So I really don’t put much faith in official pronouncements the first week of an accident.

Gundersen said it is hard to know how far radiation has spread from the plants.

“[W]e don’t have a lot of accurate measures. There’s a U.S. aircraft carrier 100 miles away, and the workers on that aircraft carrier received in one hour the dose they would normally get in one month.”

GlobalPost: Is there any risk that the radiation would reach American shores?

Oh it will. Chernobyl reached the U.S. The question is how much radiation? There’s not a lot of data to make that determination right now.

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