The Collaborative International Dictionary of English v.0.48:

nuclear power \nuclear power\ n.
   1. Power derived from nuclear reactions; -- used at present
      especially of electrical power generated in atomic
      reactors, but encompassing also fusion power.

   Syn: atomic energy, atomic power, nuclear energy, nuclear
        energy.
        [WordNet 1.5]

   2. A country possessing nuclear weapons.
      [PJC]

WordNet (r) 3.0 (2006):

nuclear power
    n 1: nuclear energy regarded as a source of electricity for the
         power grid (for civilian use) [syn: atomic power,
         nuclear power]