The explosion that ripped through the Chornobyl #4 reactor core ignited an extremely hot graphite fire that burned for six days, lifting a lot of the radioactivity high into the atmosphere, where it drifted around the globe. That spared the local population much in the same way that the winds are blowing much of Fukushima’s radiation out into the ocean where it can dilute to relative safety. In a nuclear disaster everything depends on which way the wind is blowing.
On Chornobyl’s sixth day, the graphite fire was mostly put out and radiation dropped to less than 20 percent of the first day. But then the core melt began. Radiation spiked and started including radioactive isotopes like ruthenium and zirconium that pointed to extremely high temperatures inside. For four days, the radioactive releases got bigger and bigger, reaching more than half of what came out in the initial explosion. Then, on the fifth day it stopped. To this day, no one knows why.
Without the lift from the graphite fire, the radioactive isotopes released during the core melt period were closer to the ground. You can see the gentle shifts in the southerly wind from the footprint of stronitum-90 on the radiation maps. This is probably what is happening in Fukushima — it is more like a burning stick of incense than an explosion. But it has been going for more than two weeks, in at least three reactors and one damaged fuel pond, with no end in sight.
If the Viennese weathermen are right in their estimates, and the radiation releases in Fukushima have been consistent since then, then the Japanese disaster may have already exceeded Chornobyl and, if it hasn’t, probably will before it is over. Of course, the radiation releases mostly likely have been very inconsistent, uneven and patchy. So, I would hesitate to predict with any certainty.
Fortunately, and unlike the stupid, secretive USSR; Japan evacuated the local population in a timely way so the health impact of Fukushima’s radiation has hopefully been minimized. But I suspect that the human impact may still be grave because many of those evacuees won’t be able to return to their homes. This will be especially difficult for the elderly.
For their sake, I hope that I am completely wrong.
Mary Mycio is the author of Wormwood Forest: A Natural History of Chernobyl and president of Kipling Global Media, providing international media development consulting services.. Her blogs can be found at Open Salon.
