nuclear power 
noun
1 [mass noun] Electric or motive power generated by a nuclear reactor.The Austrians have voted not to generate electricity from nuclear power stations....
- We seem to be uneasy about the generation of electricity by nuclear power, although it is far less polluting than fossil fuels.
- The main example I chose was the use of nuclear power for electricity generation.
2A country that has nuclear weapons: the confrontation between the two nuclear powers worsened...
- The phrase ‘nuclear cricket’ was used to describe the test series between India and Pakistan in 1999, the year both nations became nuclear powers.
- The five original nuclear powers have suspended production of fissionable material for weapons but a treaty on this has been blocked by India and Pakistan.
- Five nuclear powers dominate the UN's security council, which authorises military action against other countries.