radioactive decay
Technical term in physics, synonymous with 放射性崩壊 (ほうしゃせいほうかい).
See also: 放射性崩壊
Uranium eventually becomes lead through radioactive decay.
Synonym; 放射性崩壊 is more common in modern usage, while 放射壊変 is an alternative term.
Compound of 放射 (radiation) and 壊変 (disintegration).