Air Date: Week of February 18, 1994

Host Steve Curwood talks to Alexander Sich, an American nuclear engineer who recently spent eighteen months in the Chernobyl area reconstructing events following the 1986 nuclear accident there. Sich believes radiation from the damaged nuclear power plant was several times greater than levels reported by the Soviet government. On the other hand, he says his research indicates that massive nuclear meltdowns are far less likely to occur than some scientists have predicted.

Transcript

CURWOOD: Nearly seven years ago, an explosion and fire at the Chernobyl nuclear plant in the Ukraine spread a huge plume of radiation over a wide swath of Europe. The Chernobyl disaster remains the worst ever civilian nuclear accident. There's good and bad news from a new doctoral thesis just accepted by the Massachusetts Institute of Technology. On the one hand, the runaway reaction appears to have been self-limited. But there is also evidence that the Soviet government grossly understated the amount of radiation released. Dr. Alexander Sich speaks Ukranian and was the first US Nuclear engineer to get extensive access to Chernobyl. He spent 18 months in the contaminated zone reconstructing the 10-day incident and calculating the fate of the reactor's fuel.

SICH: Knowing how much was in the reactor before the accident, I was able to come up with a figure of approximately three-and-a-half times what the Soviet total release figure was. I then, by a very rough estimate, increased that to four to five times, if you include in my estimate all the radionuclides that could have been released.

CURWOOD: Let's just go over briefly what happened during the Chernobyl accident, and correct me where I'm wrong. There was an explosion and a group of fires at first, right?

SICH: Yes.

CURWOOD: And then, the reactor started to burn. It wasn't a nuclear reaction; it was a common oxidation reaction, but it started to burn.

SICH: Right. The fuel didn't burn. It was the graphite and other materials around it.

CURWOOD: But this was highly contaminated with radioactive material.

SICH: Yes. They tried to do two things. The first one was the alleged dumping of over 5,000 tons of various materials onto the core in order to smother it. The second has to do with a nitrogen purge of the core in order to cool it and drive out oxygen.

CURWOOD: And what in fact did happen?

SICH: Well, it turns out that the dumping was carried out very precisely by the very brave helicopter pilots. They were told essentially to hit the glowing red spot, which was visible from helicopters. And everyone thought that was the core. It turns out that this glowing red spot is located approximately 10 to 15 meters to the east of where the reactor shaft is and where the molten core was. What puzzles me is how the Soviet experts could not see that the core shaft was not covered, and it's quite clear from some of the stereoscopic pictures that I have.

CURWOOD: Your research and your story sounds like the accident at Chernobyl was greatly compounded by a lot of mistakes. Were these honest mistakes, or were these a function of people trying to cover up?

SICH: Um, that's very difficult to say. Initially, I think there was no intent to cover up. But I'm surprised that at Vienna they would have claimed that the core was smothered. It turns out, at least from my investigations, that the core froze by itself, solidified by itself, and stopped releasing.

CURWOOD: What are the implications of this much larger release, then, especially in terms of human and environmental health?

SICH: Well, okay. This is where I step out of my field. But iodine, radioactive iodine, which is one of the most volatile elements and also one of the most biologically hazardous ones, was released in tremendous quantities. Now, there have been noticed in Byelorussia and Ukraine, a very dramatic increase in childhood thyroid cancers. So I'm suggesting that this question should be reopened to determine whether there is a direct link between the, my findings for the increased release of iodine, and the increases of the childhood thyroids.

CURWOOD: Now what does this accident at Chernobyl tell us about the worst-case scenario, the so-called China Syndrome, the meltdown that catastrophically contaminates the earth and groundwater? Was it that bad?

SICH: No, it wasn't that bad. And in fact, that's an interesting question, because one of the positive outcomes of my research is that apparently, a China Syndrome can't happen or at least is very, very very much less likely to occur. And I'll try to lay out why that's the case. This core melted and sank to the bottom of the reactor shaft, whereupon this approximately 135 tons of fuel quickly spread out. The piping that now exists in the reactor building, along which the melted fuel ran, is from all visual indications undamaged. The concrete on the lower floors is undamaged. All you have there now is this solidified mass of highly-radioactive fuel, but little or no damage has been done to the surrounding structures.

CURWOOD: You worked inside the exclusion zone around the Chernobyl reactor for some 18 months, and you lived nearby. What was it like being there? Weren't you afraid?

SICH: No. The zone isn't - certain parts of the zone I should say aren't as contaminated or as frightful as people may believe. In fact, the little house that I was given in the town of Chernobyl isn't too bad. The background level is on the order of maybe one-and-a-half times, sometimes two times the normal background rate in Boston, for example. So it's comparable to what the background rate is in Denver, or high up in the mountains. There are certainly places in the zones that are extremely contaminated. Interestingly, old structures and trees, which made it a little bit spooky. If you would put your dosimeter up to a tree, the needle would go off the scale. Which made me wonder a little bit about the birds and other life in the zone.

CURWOOD: MIT nuclear engineer Alexander Sich spent 18 months at the Chernobyl site.