[Steely Tom]

Slide show asserts that at least one reactor’s fuel melted after boiling off coolant within the reactor vessel. Also asserts that the spent fuel in one of the fuel ponds melted.

[magellan]

Also asserts that the spent fuel in one of the fuel ponds melted.

I believe this would be unlikely. Reactor fuel melts at 3,000 degrees. The cladding surrounding the fuel rod melts at 2,000 degrees.

The water is the only radiation shielding for spent fuel. If the water boiled off, the rods would be exposed to the air, and therefore there would be radiation exposure.

[AndyJackson]

This is a good slide-show in the sense that it provides a credible sequence of events for the thermal/hydraulic/mechanical events in the plant.

We do not have any idea to what extent various fuel elements were damaged. So far isotopics suggest that Cs 137 and I131 were the main issues, but these are highly volatile products. The existence of longer lived fission products would be necessary to conclude that there was a significant breach of reactor containment.