Japan's worst case scenario
Dr. Michael Allen, an expert on nuclear reactor meltdowns, talks about some of the worst case scenarios in Japan (Hat Tip: Instapundit). The worst of the worst could come if Japan can't come up with a way to sufficiently cool down the reactor fuel cores. That has reportedly become increasingly difficult with workers evacuating the sites -- at least temporarily -- because of high radiation fields.I've heard a lot of reports of Japan using helicopters to get water into the reactors and cool their cores. What I don't understand is why they're not using the water-tanker planes that were used for the Haifa forest fire here a few months ago.
"These things play out over a long period of time, longer than people would think," Allen said. "You have an earthquake that lasts maybe a minute, a tsunami that lasts maybe 15 minutes. But these things could go on for months. You could lose all six of the reactors."
If workers are unable to get additional cooling water into the reactor vessel, the molten fuel core will collapse into the water in bottom of the vessel. Eventually the heat from the decaying fuel would boil away the water that's left, leaving the core sitting on the vessel's lower head made of steel.
Should that happen, "It'll melt through it like butter," Allen said.
That, in turn, would cause a "high-pressure melt injection" into the water-filled concrete cavity below the reactor. Because the concrete would likely be unheated, the reaction created by the sudden injection of the reactor's ultra-hot content would be immense, he said.
"It'll be like somebody dropped a bomb, and there'll be a big cloud of very, very radioactive material above the ground," Allen said, noting that it would contain uranium and plutonium, as well as the fission products.
Should these events happen, the best outcome would be if the winds are blowing east and push the radioactive plume over the Pacific Ocean, he said. "It (the radioactivity) will fall out in the ocean and everything will be fine," he said.
The worst case, Allen said, would be if winds pushed a radioactive cloud south toward Tokyo and Japan's highly populated cities. If that were to happen, he said, the consequences would likely be greater than the 1986 accident at Chernobyl, where an entire area of Ukraine had to be evacuated because of the radioactive conditions that increased the risk of developing cancer.
Should these events happen, the best outcome would be if the winds are blowing east and push the radioactive plume over the Pacific Ocean, he said. "It (the radioactivity) will fall out in the ocean and everything will be fine," he said.
The worst case, Allen said, would be if winds pushed a radioactive cloud south toward Tokyo and Japan's highly populated cities. If that were to happen, he said, the consequences would likely be greater than the 1986 accident at Chernobyl, where an entire area of Ukraine had to be evacuated because of the radioactive conditions that increased the risk of developing cancer.
Labels: earthquake, Fukushima nuclear power plant, Japan, nuclear meltdown, tsunami
posted by Carl in Jerusalem @ 12:45 PM
3 Comments:
"What I don't understand is why they're not using the water-tanker planes that were used for the Haifa forest fire here a few months ago."
Neither I ................
What I don't understand is why they're not using the water-tanker planes that were used for the Haifa forest fire here a few months ago.
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Planes don't hover. Helicopters do. This is not a forest fire, spread out over a wide area. The water needs to be efficiently dropped onto the reactor buildings.
It's way over the top to say or even hint on the possibility of any core meltdowns into the environment. Here's an article by William Tucker in the Wall St. Journal, "Japan Does Not Face Another Chernobyl".
An excerpt" "...The core of a nuclear reactor operates at about 550 degrees Fahrenheit, well below the temperature of a coal furnace and only slightly hotter than a kitchen oven. If anything unusual occurs, the control rods immediately drop, shutting off the nuclear reaction. You can't have a "runaway reactor," nor can a reactor explode like a nuclear bomb. A commercial reactor is to a bomb what Vaseline is to napalm. Although both are made from petroleum jelly, only one of them has potentially explosive material."
He goes on. There's no getting around these facts: the temperature of the uncooled fuel rods is around 550 degrees F. Unlike those at Chernobyl, ALL Western reactors have containment shells, a solid piece of steel 4" to 8" thick surrounding the entire reactor. The melting point of steel is around 2,000 degrees F. So, in absolute worst case, the melted fuel rods would be completely contained within the containment shells of those reactors. (Which BTW, are all GE designs.)
One absolutely safe prediction is that whatever the outcome, the Tokyo Electric Co., the owner of all those reactors, and GE, the designer-manufacturer are going to fact massive litigation. They're going to need regiments of lawyers.
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