[justa-hairyape]

Oops. Forgot to address your specific questions. At Fukushima water has been run into the corium for over a year. Actually the water is falling out the hole in the RPV bottom and flowing to the upper crust areas of the corium bore holes in the concrete. The very fine corium debris could theoretically be generated when the still semi-liquid semi-solid corium enters additional water under ground. That could be sent into the atmosphere via gaseous steam venting. Someone once online stated that corium has an added property of being able to spontaneously generate dust. Have not looked into that specifically, and that was stated on an anti-nuke site. A quick search just found nothing on that topic.

[GOPJ]

Thanks - glad you came back to question...

:)