atomic age; nuclear age
Refers to the historical period marked by the development and use of nuclear energy and weapons.
The dawn of the atomic age was the dropping of atomic bombs on Hiroshima and Nagasaki.
In the nuclear age, energy policy is a crucial issue.
原子力 means 'atomic energy' or 'nuclear power' itself, while 原子力時代 refers to the era characterized by it.
核時代 is a synonym also meaning 'nuclear age', but 原子力時代 is more common in Japanese.
Compound of 原子力 (げんしりょく, 'atomic energy') and 時代 (じだい, 'era').