Radiation Levels Surge Outside Two Nuclear Plants in Japan

Hydrogen is a by-product of the reactor operations - bled or burnt routinely.....for some reason the damaged systems precluded the venting of the containment (or operator errors) and H2 built up in containment. Igniters are fitted in containment for such an accident - but no power. KABOOM...


The Japanese government's chief spokesman, Yukio Edano, said the concrete building housing the plant's number one reactor had collapsed but the metal reactor container inside was not damaged. H2 in containment blew after igniters lost all power. Containment gone - real issue is the condition of the vessel housing the core......after the blast (rupture of seals between head and vessel with an uncovered core leads to the "China Syndrome" scenario (kidding)). Engineers worry over basemat integrity.......hope it was properly "worried".

This accident scenario has been extensively reviewed for decades (scale models built) and all us smart engineers thought we had it covered ..........GE design.

Thanks for sharing the expertise and knowledge on this.

Yes, thanks for the great info. To me it seems that it is not good to have the roof missing. I also read that that power plant is not as new as the other ones but they did have it to code.

Define "to Code"......

Be aware the "roof" is a facade - under the roof is the containment and IN the containment is the vessel with the core.

http://news.bbcimg.co.uk/media/images/5 ... 04x171.gif

file:///Volumes/ZIP250/PICTURE%20FILES/bwr.gif

You know what, I am not sure on this because I heard it at 3 in the morning on CNN. All I know is the one that is having the worst problems is the 'older' one. (40 years old) According to what I have seen and read, Japan has very stringent rules and regulations and that one is probably not state of the art but according to the Television they still were making sure it had redundant safety features. The problem is that all of them failed, because this was so catastrophic.

http://www.washingtonpost.com/wp-dyn/co ... 01879.html

Either way this makes it very difficult to help with recovery. I am sure people are afraid to go there and help.

"Domres said that he, like nearly everyone here, was in the dark about exactly what had happened and added that he wouldn't be driving too far north until he finds out. "It is certainly not advisable right now," he said.

If winds shift and serious leakage has occurred, he warned, "a cloud will approach this area loaded with radioactive material." On Saturday, Japanese police sealed off major roads leading north, and trains were not running to the area.

Fear of radiation added another layer of alarm Saturday as aftershocks continued. "It's freaky," he said. "Japan is extremely safety-conscious and would have cleared us out" if the risk of contamination were serious.

"Unless it is too late," he added wryly.

Domres, the surgeon, said he had traveled to Haiti twice after the earthquake there in January 2010.."

ALL the regulations will not preclude marginal design and poor decisions. The diesels of course should have been "high and dry"....a loss of all power is the death nell for a commercial nuclear plant. "outside" power is essential to keep water flowing over a core to remove decay heat. Decay heat melts cores.

The way commercial folks think is focused on $$$$$ - and marginal designs are rationalized based on low probabilities of accidents. - NOW, these reactors are at sea level openly exposed to earthquakes and tsunamis - well known - why even build there ?? It was risky.......but low probability........always the commercial argument.