See Update Below
See second update
One way I misspent my youth was by working for Ralph Nader's Critical Mass Energy Project (in a very lowly role). I helped to organize the Critical Mass '78 conference, where I had a chance to meet Hazel Henderson and to hear Ted Kennedy and Rep. Leo Ryan speak. Ryan was murdered just a few months later by followers of Jim Jones, in Guyana. So I took that kind of personally. Then I helped to organize the huge march on Washington following the Three Mile Island debacle. Along the way I learned quite a lot about nuclear power and the issues surrounding it.
I haven't had much to do with energy policy since then, at least not professionally, but I haven't forgotten anything. Accordingly, the truly crappy job your corporate media are doing explaining the situation with the reactors in Japan is really frosting my pumpkin.
These are good old fashioned boiling water reactors, the same kind as TMI and the standard model back in the day. I heard an "expert" on CNN claiming that the control rods had gone in as soon as the earthquake alarm sounded, so there was no danger of a core melt down. Not even close. The control rods stop the fission chain reaction involving U-235 which is the main way the reactor produces power (i.e. heat). However, the problem comes from other, much shorter lived but therefore much more highly radioactive species that are created as a byproduct of the U-235 chain reaction. If the cooling system fails, which is what has happened, the heat produced by the decay of these isotopes builds up until the entire mass of fuel melts its way through the pressure vessel and lands on the floor of the concrete containment structure. (I use the present tense, but this has never actually happened yet. It's hypothetical.) From there, if it eats through the containment, it could hit groundwater, resulting in a steam explosion and widespread dispersal of radioactive particles, or simply migrate in groundwater or otherwise get to all kinds of places.
The Japanese engineers, having evidently lost all of their designed options to cool the cores at two reactors, are using seawater. It is not clear how they are doing this or if radioactive water is being discharged back to the ocean, but in any case, as you know, seawater is corrosive and will destroy the pumps and pipes in due course. So it seems pretty desperate.
A Chernobyl type event cannot occur with these reactors. Chernobyl was graphite moderated and the graphite caught fire, which is what produced such wide dispersal of radioactivity. It's quite unlikely that a high level of contamination will spread very far. However, these reactors are now totally destroyed. In addition to the dead loss of the power plants -- which cost billions -- clean up costs will be enormous, as is the cost of the necessary evacuation, which will likely have to be enforced for a long time.
There are many objections to large-scale use of nuclear power, but unfortunately, in my view, the politics of the issue have focused almost entirely on concerns about safety, mostly championed by NIMBY constituencies. The risk of a large scale public health catastrophe is quite low, and we accept an ongoing but 100% certain catastrophe from burning fossil fuels with seeming equanimity. However, nuclear power is not a good bet economically, because individual plants are extremely costly -- as they must be to be acceptably safe -- and when things go wrong, they can go very wrong. And, when their useful life is over, even if they get there safely, they cost a fortune to clean up.
Therefore, investors won't pay for them without government subsidies in the form of liability limits and cheap insurance, tax incentives, and dumping the cost of decommissioning and part of security onto the public, whether as ratepayers down the road, or taxpayers today. As much as we all would like a painless way out of the environmental crisis caused by our fossil fuel based economy, nuclear power ain't it.
Update: First, a bit more information. Apparently what they are doing is pouring in seawater and then venting the steam. This would obviously result in a low-level, but continuous release of radioactive particles to the atmosphere. That does appear to be what we are seeing. Although the authorities continually downplay this, it's certainly not good. So far the wind has been carrying the plume out to sea, where a U.S. navy task force encountered it, causing them to leave the area. When the wind shifts onshore, it will waft over the land.
The public health and moral issue here is complicated. The consensus belief is that there is no safe level of ionizing radiation -- we are all exposed to ionizing radiation all the time, but slightly more means a slightly higher life-long risk of cancer. On the other hand, although I don't know precisely what degree of contamination we're talking about from the current situation, for people living nearby this is probably less than the risk people experience from living near a major highway. On the other hand they didn't know about it when they decided to live there. It is troublesome that they don't seem to have a plan B. If they have to keep pumping in seawater and venting the steam, this could continue for months, until the hot isotopes cool down enough.
But, the situation could certainly get worse. They are now admitting that there have been partial core melts in at least two, and probably three reactors. If the pressure vessels are damaged, and a pressure vessel is ultimately breached, they have much bigger problems. That would mean there is no way to keep the core immersed in coolant and you'll have a mass of molten material on the floor of the containment. From there, more substantial releases of radiation would be probable. So this is a big mess.
On the subject of corporate media idiocy, I switched on CNN yesterday afternoon to get an update on the situation. Don Lemon was interviewing a doofus in a bow tie. Don said, "And here's Bill Nye, who you probably know as a science guy." Then he asked the doofus to explain what a meltdown means.
The guy said -- I can't quote exactly but the substance is guaranteed 100% accurate -- that uranium is really heavy, it's the heaviest naturally occurring element. When you get U-235 in a certain configuration (really, that's as specific as he got) it gets really hot. So it's really heavy and therefore when it melts it goes down. That was the answer of the science guy.
To reiterate, a reactor core meltdown is not caused by the uranium. Uranium -- no matter how highly enriched with U-235 -- is only very slightly radioactive. You could actually carry a piece of it around in your pocket and it would be minimally dangerous. It doesn't get hot. It is a fission chain reaction that generates heat, and that has been shut down. The heat is generated by other radioactive isotopes which contaminate the fuel as a byproduct of fission.
So the Science Guy is an ignorant idiot who hasn't the slightest idea what he is talking about. Why on earth such a fool gets such a platform is incomprehensible.
Update 2: Apparently the pressure vessel in one of the reactors is leaking. That is a very serious situation. Stay tuned.