noun
nuclear fission reaction
Technical term used in physics and nuclear engineering. Refers specifically to a reaction in which an atomic nucleus splits into smaller parts, releasing energy.
原子力発電所では核分裂反応を利用して電気を作っている。
Nuclear power plants generate electricity using nuclear fission reactions.
核融合反応 (nuclear fusion reaction) is the opposite process, where atomic nuclei combine. 核分裂反応 is fission, splitting nuclei.
Compound of 核 (nucleus), 分裂 (splitting), and 反応 (reaction). A straightforward technical term with no obscure historical derivation.