I imagine step one is to launch from the coast heading out over the ocean. If Starship is fully operational by then it would be the obvious choice and depending

I imagine step one is to launch from the coast heading out over the ocean. If Starship is fully operational by then it would be the obvious choice and depending on the reactor design there might be enough weight capacity to build in some extra shielding. I also wonder if the fuel can be shipped separate from the reactor.