that will pass. With Starship you can deliver reactor into orbit in a "safe box" such that if anything happens with the rocket during launch and acceleration the box with the reactor will fall without breaking apart. And you don't need it for the whole reactor, only for the nuclear fuel.

You don't need anything at all. A reactor that has never been turned on is not radioactive. The only protection you need is to simply not start the reactor until it's on a planetary escape orbit, one that does not return.