[FoRK] Why Fukushima made me stop worrying and love nuclear power

Damien Morton dmorton at bitfurnace.com
Wed Mar 23 14:35:20 PDT 2011

On Wed, Mar 23, 2011 at 4:02 PM, Stephen Williams <sdw at lig.net> wrote:

> The main worst case scenario is scaring a lot of people.  In a modern,
> practical nuclear plant, it doesn't seem possible under any scenario to
> cause more overall damage and cost to people than our currently dominant
> energy sources already do every year.

 """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.

"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

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

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