Originally Posted by
Excargodog
Easier just to do a conventional detonation in place. Let the 60% uranium flow together and reach at or near critical mass. A Chernobyl-like event 500 feet underground would leave even the unreacted enriched Uranium unrecoverable for - one hell of a long time. There have been mishaps like this on a smaller scale in Plutonium manufacture, where through accident or stupidity plutonium nitrate solutions have been allowed to form a critical shape. The cleanup is long, expensive, and the mixed reaction products cheaper to just bury for a few millennia and start over rather than even attempt a hazardous separation process. We don’t actually need their enriched Uranium if we can just see that they don’t get it for a few thousand years.
Sort of.
The likely utility of such a strike would be to bury it deep in such a manner that would require protective gear and special handling to dig it all out again. Harder for IR, but not impossible by any means, and not worth the inevitable geopolitical blowback (wouldn't go over well at home either).
Possible if the material was stored shallow enough that you could scatter it to the winds, making recovery essentially impossible. Or could do that with multiple strikes, keep digging until you get to the chewy center basically. But now you've created even more fallout, and bathing enriched U in neutron flux from a weapon would tend to warm it up a bit . Bad news for whoever is downwind.
Chernobyl is not relevant to this discussion at all.
1) Yes Chernobyl experienced a (relatively small) bomb-like event in the core (prompt super criticality). This blew the core apart and scattered the contents outside containment.
2) But the reactor core itself was already a very hot pile of isotopes (due to lengthy production operation), and more massive than any bomb core by orders of magnitude. I don't think even a big bomb that neutron-irradiated a pile of enriched U would cause that big of a mess. RBMK was (is actually) a monumentally bad design.