Power and protection for a future railgun cruiser

Could a railgun warship be a modern cruiser, and would it need nuclear power?

Expect a large cruiser-like platform, with a compact reactor as one possible answer to its power demands rather than a settled outcome.

A future railgun combatant is estimated at roughly cruiser-scale displacement, perhaps ten to twelve thousand tons. Power generation would be a major driver of that size. A compact Rolls-Royce-style naval reactor is raised as one possible source if conventional generation proves inadequate. Concern about nuclear-powered surface ships and the consequences of sinking would make that an engineering and political choice rather than an automatic outcome.