Good BBC article on Japanese reactor explosion ...

[eppur_se_muova]

Huge blast at Japan nuclear power plant

By Richard Black
Environment correspondent, BBC News

***
If the water stops flowing, there is a problem. The core overheats and more of the water turns to steam.

The steam generates huge pressures inside the reactor vessel - a big, sealed container - and if the largely metal core gets too hot, it will just melt, with some components perhaps catching fire.

In the worst-case scenario, the core melts through the bottom of the reactor vessel and falls onto the floor of the containment vessel - an outer sealed unit.

This is designed to prevent the molten reactor from penetrating any further. Local damage in this case will be serious, but in principle there should be no leakage of radioactive material into the outside world.

But the term "in principle" is the difficult one.
***
more: http://www.bbc.co.uk/news/world-12723092




The technical stuff is broken down into bite-size pieces. Covers all the main points (insofar as is known at present) rather well.

ETA: Reporter takes a skeptical, informed view -- not "pro" or "anti" nuclear -- a fair amount of "one the one hand ... on the other ..."

[pinto]

1. Good article / overview.

:thumbsup:

[bbinacan]

2. Thanks for the info. n/t

[hunter]

3. There's decent coverage on some of the tech sites.

I grabbed this picture off wikipedia:



http://en.wikipedia.org/wiki/Fukushima_I_Nuclear_Power_Plant

At the top of the reactor building is metal enclosure housing the service crane. This enclosure apparently filled with hydrogen and exploded, blowing the metal paneling off. You can see the panels in the video. Hydrogen will leak out of anything given the slightest opportunity.

Last I heard, the concrete and steel containment is still secure.

There's some intelligent coverage at World Nuclear News, and a good diagram of this type of reactor. Yeah, yeah, World Nuclear News, but I've pretty much given up on OMG! We're all gonna die! postings here on DU, CNN, and elsewhere. Some of the comments at the Oil Drum are hideous beyond belief... bless the DU moderators it's not so bad here.)

http://www.world-nuclear-news.org/RS_Battle_to_stabilise_earthquake_reactors_1203111.html

It can't be easy for the nuclear techs and engineers at Fukushima. I'm sure a number of them have friends and family who are not accounted for.

[applegrove]

4. Thanks for posting. I passed on this article to my brother in Japan.