What nuclear power could unlock on a 20,000-ton cruiser

What could the modern US Navy put on a class of nuclear-powered 20,000-ton cruisers?

Extensive VLS, lasers, and potentially workable railguns or coilguns, with metallurgy and projectile guidance remaining important constraints.

Nuclear generation gives a 20,000-ton cruiser the sustained electrical power and internal volume needed for demanding weapons. It addresses repeated capacitor charging, one of the central burdens in making a railgun fire usefully rather than only once in a test. Barrel lining and metallurgy would remain difficult even after the power problem was eased. Railguns can throw simple kinetic projectiles, while coilguns may be easier to develop but would need guided ammunition at long range. The power plant changes the feasible weapons mix as well as the ship's endurance.