So I decided it was a good idea to introduce Demolishers to 8t warheads... I also blew up my only rocket silo and landing pad and had to brute force Vulcanus after that.

Noticed a few things though that kind of break the balancing on Vulcanus:
1) Nukes trivialize "unlocking" new territories. All you need is to walk up to any Demolisher and use a 8t warhead to destroy it, which are relatively easy and cheap to craft on Nauvis. I get that the same can be said for the railgun but that is a tech that is unlocked way later than the mod's "Atomic Bomb" research.
How about making all warheads too heavy for the rocket (including the raw uranium / californium)?

2) The craters eventually contain water (on a planet that is one big waterless volcano).
Suggestion: Similar to vanilla's nuclear explosion mechanic, the craters should fill up with the planet's main fluid, which is: Water for Nauvis / Gleba, Lava on Vulcanus, Heavy Oil on Fulgora and Ammonia on Aquilo.

Thoughts?

To add to this, I also think balancing is a little wacky for vulcanus, but I don't think disallowing uranium transportation is a good solution. What about nuclear fuel cells, for example? You would then have to prohibit transportation of those too, because if not, you could get those on vulcanus, then recycle for uranium. But completely stopping the player from using fission power outside of Nauvis seems a little extreme, no? Same goes for personal fission reactor.

I think giving the worms a ridiculously high resistance (but not complete immunity) to explosions is a better solution, so that you can't trivially kill them with 8t warheads, but it's still feasible to use higher yield nukes on them.