I found a more reliable source for the cost of naval nuclear reactors: the Congressional Budget Office [1]. They investigated what it would cost to switch some surface ships from conventional to nuclear power. The main result:
"CBO estimated that the acquisition-cost premium for a nuclear ship would be about $1.1 billion per destroyer, $0.8 billion per LSD(X), and $0.9 billion per LH(X)".
In particular for the last class LH(X) (helicopter carriers, similar to the Wasp class), the reactors would be two A1B used in the Gerald Ford class of aircraft carriers, which generate about 700 MW.
"CBO estimated that the acquisition-cost premium for a nuclear ship would be about $1.1 billion per destroyer, $0.8 billion per LSD(X), and $0.9 billion per LH(X)".
In particular for the last class LH(X) (helicopter carriers, similar to the Wasp class), the reactors would be two A1B used in the Gerald Ford class of aircraft carriers, which generate about 700 MW.
[1] https://www.cbo.gov/sites/default/files/112th-congress-2011-...