A rocket explosion is unlikely to pulverize solid nuclear fuel or vitrified nuclear waste. It would most likely fall, intact or in large pieces, into the ocean which is a pretty good place for it anyway. If it blows up over Florida that's worse, but the worst case scenario is that it reenters earth's atmosphere at near-orbital speeds over a populated area and burns/breaks up. Then you have a situation like Kosmos 954, where the radioactive material is spread over a large area and is consequently much harder to clean up.
The biggest issue for the nuclear waste disposal idea is that it doesn't make any economic sense. It's better to dump it into the ocean, or down a mineshaft, or even just to let it sit in storage near the power plant for decades. But with nuclear fuel for rovers, satellites or rockets the rewards could outweigh the risks, and so this is sometimes done.
> The General Purpose Heat Sources (GPHS) inside the
MMRTG is designed specifically to prevent such an occurrence. The fuel inside each GPHS is surrounded by
several layers of protective materials, including the type
of tough material used in the nose cones of missiles
designed to survive fiery conditions during re-entry into
Earth’s atmosphere. In addition, the radioisotope fuel
is manufactured in a ceramic form (similar to the mate-
rial in a coffee mug) that resists being broken into fine
pieces, reducing the chance that hazardous material
could become airborne or ingested.
> The biggest issue for the nuclear waste disposal idea is that it doesn't make any economic sense.
No the biggest issue is that its a stupid idea in the first place. Nuclear waste is fine and perfectly reasonable to handle here on earth with close to zero chance of actual danger.
The biggest issue for the nuclear waste disposal idea is that it doesn't make any economic sense. It's better to dump it into the ocean, or down a mineshaft, or even just to let it sit in storage near the power plant for decades. But with nuclear fuel for rovers, satellites or rockets the rewards could outweigh the risks, and so this is sometimes done.
Here's a NASA doc that goes over the risks of launching plutonium into space for their Mars rovers. To summarize, it's not really a big deal: https://rps.nasa.gov/resources/81/mars-2020-launch-nuclear-s...
> The General Purpose Heat Sources (GPHS) inside the MMRTG is designed specifically to prevent such an occurrence. The fuel inside each GPHS is surrounded by several layers of protective materials, including the type of tough material used in the nose cones of missiles designed to survive fiery conditions during re-entry into Earth’s atmosphere. In addition, the radioisotope fuel is manufactured in a ceramic form (similar to the mate- rial in a coffee mug) that resists being broken into fine pieces, reducing the chance that hazardous material could become airborne or ingested.