4 ms·

https://en.wikipedia.org/wiki/Corium_(nuclear_reactor) https://en.wikipedia.org/wiki/Corium_(nuclear_reactor)

• TheSpiceIsLife 10y ago
  From the link you provided: The fast erosion phase of the concrete basemat lasts for about an hour and progresses to about one meter in depth, then slows to several centimeters per hour, and stops completely when the melt cools below the decomposition temperature of concrete (about 1100 °C). Complete melt-through can occur in several days even through several meters of concrete; the corium then penetrates several meters into the underlying soil, spreads around, cools and solidifies.[3] This would seem to counter the claim that the molten core material could burn through hundreds or thousands of feet of earth.
  • ethbro 10y ago
    Isn't all of this dependant on the composition of the corium? As that's what defines how much heat is being added to itself via nuclear reactions? Per my understanding, it will always be sub-critical without correct geometry and neutron moderators. But wouldn't the precise amounts and percentages of various materials in the molten sludge vary thermal output?
    • TheSpiceIsLife 10y ago
      That's the way I read it. I find it hard to believe there are any circumstances under which a hundreds-of-megawatts to gigawatts core could remain hot enough to burn through hundreds or thousands of feet of earth.