Friday, March 11, 2011

Japan Earthquake - Reactor to vent radioactive steam

Article

This is following the classic scenario for a loss of coolant accident (LOCA).  The pressure is now above design within containment.  They are keeping it there for a reason, and cannot hold it any longer.  Lots of iodine isotope coming out, folks.

In Canada, with the Candu plant, we have a vacuum building for such a purpose.  The steam would be sucked into this massive building, and condensed (turned back into water) by a dousing system.  The radioactive water would go out into the lake instead of the atmosphere.

Looks like they are waiting for a favourable wind.

9 comments:

Harold Asmis said...

-generators knocked out by tsunami
-pressure still rising
-only 8 hours of battery

Normally, we never credit batteries to operate the coolant pumps. The emergency core coolant is in a big tower that is supposed to be earthquake rugged. Seems like a flaky operation here.

Harold Asmis said...

Talking to a nuclear person, we surmise that this is a very old BWR, with something like 8 other units. We can't imagine why they can't just fire up one of the other units for electricity.

Harbles said...

Perhaps it's Xenon poisoning which builds up if power goes below 60% which makes controlling reactivity difficult. Also with no grid power and gennies washed away by Tsunami (what were they thinking there?)getting the pumps going is difficult.
I heard that the USAF was delivering 'some coolant' to the plant, maybe they meant a portable generator?

Harbles said...

Some news stories say 1.5 times 'normal ' radioactivity around plant others say 1000 times. Any radioactivity is too much (especially in particulate form). If they don't get cooling pumps going soon it will be very bad I fear. You could sling one of these under a Chinook. Is 400 KVA enough to drive the pumps and would the voltage be compatible? Who knows. I'm staying tuned though.

http://goo.gl/maps/wCYY http://goo.gl/maps/wCY

Harold Asmis said...

Very conflicting reports. They say they have emerg. cooling, so I think they are still trying to save the reactor. I think there once was a plan for Pickering for firetrucks to hook up and pump for the uber-emerg.

Anonymous said...

Lots o reporting of reporting.
Little real info
Here's something of a source, if you believe it!
http://www.tepco.co.jp/en/press/corp-com/release/index-e.html

Peter of the vibrating lines..

Harold Asmis said...

That's cute. Looks like the gov't has ordered them to start direct injection. One employee was hit by high radiation.

Anonymous said...

They're going to flood one with sea water
Peter

Harold Asmis said...

In a typical Japanese manner, I think they left core cooling too late. They struggled too much with standard cooling despite a LOCA. It took the gov't to order direct injection. Once you write off the reactor, you can use any ditch water you find.