Japan's nuclear disaster

it's far worse than 3 Mile Island, but not anywhere as bad as Chernobyl. that hydrogen explosion at Daitchi 2 (?) puts us in a wholly unexplored commercial reactor technology region.

in the great scheme of things, they have wrecked reactors inside of containment buildings.  from what i've read, they expect the cores in one or two of the reactors to be partly melted.  the reactors are set up to work with a certain fuel arrrangement geometry that maximizes heat given off to the water that is passing through it to boil the water.  when that geometry has been changed to a multiton lump of playdoh, the reaction gets very hot and stays hot.  it will have to be actively cooled a long time.

3 mile island had a release of gas.  Chernobyl caught fire and spewed particulates around the world.  fortunately, most of the stuff was heavy and dropped locally.  the japanese reactors are leaking cooling water with entrained fission products.  currently, the most notable one is Iodine 131 which has a very short life of 8 days.  the other products given off are the longer lived cesium (which acts like sodium in the environment) strontium (which acts like calcium) and another longer lived isotope of iodine that have half lives measure in the 20-50 year range.  we all saw those radioisotopes when we were all living under atmospheric a bomb and h bomb tests.  we got by.

this is not something to be taken lightly, but its not the end of the world.  its a wakeup call that it is time to keep a wary eye on all boiling water reactors.  its also time to get off our duffs and start building the latest nearly failsafe generation 3 reactors, or else we'll be forced to go to more coal and gas as the older reactors are being retired.

Of course, this is a serious situation with radiation from the accident now being detected in the United States.

It reminds me of the anti-nuclear poster from the 60's....

Bump! 

I'd really like to get a better handle on what the world is facing from this. How far will it spread? What, exactly is going on inside the reactor?  What is the worse case scenario....which would appear is what we are facing? Any physicists, engineers, or lay people who have a better understanding of this?