What Britain would need to build a nuclear carrier or cruiser

How long would the UK take to field a nuclear carrier or nuclear cruiser, and what industry would it need?

Around a decade under normal conditions, chiefly because a nuclear-qualified surface yard and a full industrial programme would need to be established; an urgent national project might be faster.

Britain already has submarine-reactor expertise, Rolls-Royce knowledge, and work on small modular reactors that could inform a surface plant. The missing piece is a surface-ship yard certified and organized to build and support nuclear vessels. Under ordinary conditions a nuclear carrier or cruiser is estimated at roughly a decade from decision to commissioning. A national-priority programme might compress that to about six years, but only through exceptional effort and compromise. The critical path is therefore industrial certification and ship integration rather than discovering reactor physics from scratch.