[lightknight]

Hmm. The problem is that self-replicating machinery, like all robots, would get a little squirrely when exposed to that much ionizing radiation. You'd basically need several humans, hiding out in a radiation-hardened shelter, to run out every 15 minutes, to reflash the machine's OS, because the radiation is going to start randomly flipping bits, and soon, the robots that were supposed to build a reactor will start building a sand castle instead. Only there's no sand.

Look how much trouble we've had with the Mars rovers: we can't even get the instructions right half the time. And it takes several hours to see if we can recover from some really stupid mistakes. And the funny part is this: I'm saying this, and I wouldn't want to be caught dead outside during a ionizing radiation spike; you'd think I'd be all for the robots handling it all.

So I think that's the first problem we need to address: we need much better radiation shielding, and faster engines (either that or status chambers, immortality, etc.).