noun
anti-nuclear movement
Refers to organized activism or a social movement opposing nuclear weapons or nuclear power.
彼女は学生時代から反核運動に参加している。
She has been involved in the anti-nuclear movement since her student days.
反核 is the broader 'anti-nuclear' stance or attribute, while 反核運動 specifically denotes the movement or campaign.
Compound of 反 (anti-) + 核 (nuclear) + 運動 (movement).