While I realize it was likely impractical to meltdown reactors just to develop the technology to clean them up, I find the process here pretty interesting. A lot of good engineering has gone into the effort, and the engineering challenges (and risks) of post runaway reactors has gotten a lot more data.
The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the remains of the nuclear fuel which they call the "elephant foot."
I also find it interesting that the "China Syndrome"[2] speculation is pretty much completely debunked. Molten/melted fuel diffuses into the material it is melting into until it loses criticality and then freezes where ever it is. All modern reactors have a borosilicate sand pile underneath the reactor. The boron acts as a neutron absorber (poison) which stops the chain reaction once the fuel has been glassified by the silicate.
[1] It is too radioactive for that to be literally true, but it is on a floor with direct access rather than being underwater and only accessible through cracks as the Fukishima fuel is.
[2] Speculation that a blob of melted core material would just keep melting into the ground until it "got to china" (which in fact would be interrupted by getting to the earths core).
[3] EDIT: Corrected for the effects of Boron on the reaction acting as a neutron poison (absorbs neutrons) rather than a moderator (which just bounces them around)
The Chernobyl folks just entombed everything, which is a one approach, even though they can "walk up to"[1] the remains of the nuclear fuel which they call the "elephant foot."
I also find it interesting that the "China Syndrome"[2] speculation is pretty much completely debunked. Molten/melted fuel diffuses into the material it is melting into until it loses criticality and then freezes where ever it is. All modern reactors have a borosilicate sand pile underneath the reactor. The boron acts as a neutron absorber (poison) which stops the chain reaction once the fuel has been glassified by the silicate.
[1] It is too radioactive for that to be literally true, but it is on a floor with direct access rather than being underwater and only accessible through cracks as the Fukishima fuel is.
[2] Speculation that a blob of melted core material would just keep melting into the ground until it "got to china" (which in fact would be interrupted by getting to the earths core).
[3] EDIT: Corrected for the effects of Boron on the reaction acting as a neutron poison (absorbs neutrons) rather than a moderator (which just bounces them around)