[Enthalpy]

Hi!

Several sites at Fukushima contain fissile fuel which, if things turn even worse than now, may completely melt, separate from dried borated water, and concentrate in some hole, in which case Tepco doesn't exclude a more polluting criticality accident (= a slow chain reaction), including at reactor #3 which is loaded with the more reactive plutonium and uranium (Mox).

I figured out somehow that some bed of pebbles could be brought in and under the reactors and ponds, so molten fuel would be less dense, and possibly the neutrons be absorbed... Not necessarily realistic, but anyway, it would need a dense refractory compound that stays solid and in place when liquid uranium oxide flows on it.

This leaves little choice, but tantalum compounds meet these two criteria, for instance the metal, the carbide, the nitride and the boride, an efficient absorber of slow neutrons. Tantalum is available in quantity in Japan.

Your opinion please? Is this any sensible? Thanks!