"Atompowered" suggests a source of energy that is derived from the power of atoms. Some synonyms for atom-powered could include nuclear-powered, atomic-powered, or reactor-powered. Nuclear power is a type of power generation that harnesses energy from nuclear reactions. Atomic power is another term for nuclear power and is used to describe power plants that produce energy from nuclear reactions. Similarly, reactor-powered refers to power sources that use a reactor, such as a nuclear reactor, to generate electricity. These synonyms can be used interchangeably to describe the same thing, which is energy sourced from atoms through nuclear reactions.