For the record an RTG was recovered from the seabed after a launch failure intact - and then relaunched! https://rps.nasa.gov/about-rps/safety-and-reliability/

I'm sure the same can be done for nuclear reactor fuel. Even better actually, as reactor fuel is basically just a very expensive and pure heavy metal & only slightly radioactive. Only once the reactor is first started all sorts of unstable radiation releasing elements are formed in the fuel.

So if you only start the reactor once it is in space & pack the fuel securely for launch, all should be good to go! :-)

The voyager probes from the '70s are both nuclear powered.

The difference is that a Voyager from 70's nuclear engine if it fails and explodes on launch you'll get the equivalent of Beirut explosion at worse. This one looks like Hiroshima instead. I don't think people living in nearby cities would appreciate that.

Nuclear reactors don't explode. The risk is the chemical rocket exploding and spreading the nuclear fuel. The fuel doesn't get very radioactive until the reactor is started and proper packaging can protect against that.

Nuclear reactors don't explode? I suppose then Chernobyl was just another bomb and this: (https://en.wikipedia.org/wiki/Chernobyl_disaster) is just the official cover-up, eh? </sarcasm>

It was not a nuclear explosion. If it were a nuclear explosion there wouldn't be anything left of the building and other reactors around it and capping it with a concrete and steel structure would be rather pointless.

> It was not a nuclear explosion.

The claim upthread was not “nuclear reactors don't have nuclear explosions” (which would also be overgeneralized), but “nuclear reactors don't explode”. The reactor at Chernobyl did explode. The fact that it was a steam explosion induced by energy from a nuclear chain reaction and followed by a reactor core fire does not change the fact that it was a nuclear reactor, and it did explode.

> If it were a nuclear explosion there wouldn't be anything left of the building and other reactors around it and capping it with a concrete and steel structure would be rather pointless.

You seem to be confusing “nuclear explosion” with “nuclear explosion whose yield is maximized via explosive containment, in the manner typical of deliberately engineered nuclear weapons”.

Let me be more clear: powered off nuclear reactors don't explode. You can blow them up and make a mess, but you can't have a critical excursion without first turning the reactor on, which would be very hard to do with an explosion. Even if you pulverized the fuel elements on the explosion (that's one hell of an explosion), it wouldn't be as bad as Chernobyl or Fukushima because until you start the reactor, the nastiest isotopes won't be there.

I believe a bomb is nuclear fuel surrounded by explosives in order to trigger nuclear fission through compression, which in turn will generate the nuclear explosion. Powered off nuclear reactor that sit on top of a lot of fuel, fuel that has many times the explosive power than the explosives that are surrounding the bomb core, can become an atomic bomb.

Personally I would prefer such a rocket to lift off from a secluded location way out there in the ocean, in case something goes wrong and becomes an atomic bomb instead. And I like to think that people with common sense think like me as well. Do you personally have common sense?

No? Then what was it?

Quote from said wiki: "The reactor explosion killed two of the reactor operating staff."

Yeah, I guess it wasn't an explosion </sarcasm>

And North Korea underground explosions that were detected and consequently destroyed some of their underground facilities were too nuclear explosions. You know, there is such big explosion and smaller explosions.

> No? Then what was it?

A steam explosion. That's very different from a nuclear explosion.

> And North Korea underground explosions

Those were not reactors exploding. Those were bombs, which were pretty much designed to explode and, as expected, exploded.