From The Hill:
Senate Homeland Security and Governmental Affairs Chairman Joe Lieberman (I-Conn.) said the United States should issue a moratorium on any new nuclear power projects in light of the current crises facing Japan.
“I’ve been a big supporter of nuclear power because it’s domestic, it’s ours and it’s clean,” Lieberman said in an interview with “Face the Nation.”
“We’ve had a good safety record with nuclear power plants here in the United States … I don’t want to stop the building of nuclear power plants, but I think we’ve got to kind of quietly, quickly put the brakes on until we can absorb what has happened in Japan.”
With all due respect Senator, in spite of the hysteria inducing media hyperventilating about meltdowns and another Chernobyl we have fairly good idea what happened in Japan… In short there was natural disaster of near biblical proportions (a magnitude 9 earthquake and tsunami) which caused the reactors to shut down. Said natural disaster knocked out power to primary coolant system — the electric pumps that circulate water through the reactor.
On top of that it appears the quake and/or tsunami also knocked out the backup or secondary cooling system that sprays water onto the outside of the primary containment vessel (to cool the water inside). Now, with both primary and secondary cooling systems out of action they’re down to their third and final backup — pumping sea water and boric acid directly through the core.
A couple of other points, first, with the primary and secondary cooling systems offline the water in the reactor begins to heat up and water boil, this produces stream eventually you have to relieve that steam pressure. So you vent steam. This steam contains hydrogen gas which collects under the roof of the secondary containment build until something causes it ignite and blow the roof off the joint… Which are the explosions we’ve seen in news reports.
Second, this notion that Japan is head for a Chernobyl like disaster is complete nonsense, the reactor designs and safety systems are complete different. What happened in Chernobyl simply can not happen with a Pressurized Water Reactor or Boiling Water Reactor like those used here and in Japan.
Anyway that’s the layman’s guide to the problems in Japan. For an much more detailed explanation and discussion of what’s happening see this thread over at Blackfive… Pay particular attention to this comment by Subsunk and this one by grtflmark. I’d also strongly recommend reading William Tuckers op-ed “Japan Does Not Face Another Chernobyl” in today’s Wall Street Journal.
Edit: Just to clarify things a little. To the best of my knowledge the reactors at Fukushima Daiichi are shutdown, meaning the control rods are in place shutting off the nuclear reaction.
That doesn’t mean the reactor immediately goes cold there something called “decay heat” which comes from traces of other radioactive isotopes. Once a reactor is shut down it can can take a week or more for that “decay heat” to dissipate. Throughout that process coolant — water must be kept circulating through the core to keep it from overheating.
The problem the for Japanese right now seems to be keeping enough water circulating through the reactor cores to dissipate that heat.
Related
- Nuclear Overreactors – William Saletan, Slate.com
- Why Japan’s Nuclear Meltdown Is No Chernobyl – Owen Matthews, The Daily Beast
- Japan Nuclear Fallout: How Bad Could It Get? – Josh Dzieza, The Daily Beast
- Nuclear industry vows that lessons from Japan will make reactors ‘even safer’– MSNBC.com
- Nuclear Overreactions – Wall Street Journal
- Radiation’s Effect Depends on Amount -Wall Street Journal
- Radiation falls at Japanese plant – BBC News
Additional Information
- Information on the Japanese Earthquake and Reactors in That Region – Nuclear Energy Institute
- IAEA Update on Japan Earthquake – International Atomic Energy Agency
- World Nuclear News
- Tokyo Electric Power Company Press Releases