Prior to Russia’s invasion of Ukraine, the direct targeting of nuclear power plants (NPP) was largely unimaginable in armed conflict. International humanitarian law (IHL) requires their protection, but since February 2022, Russia has directly targeted nuclear facilities, including the nonoperational Chornobyl NPP and the operational Zaporizhzhia NPP. This Article documents how NPPs in Ukraine have come under direct attack, been occupied, and used for military purposes. It highlights the challenges owing to (1) the complexity of NPP infrastructure and (2) the growing presence of international actors who have not had to engage previously in the protection of NPPs; and explores policy measures that might strengthen IHL and provide accountability mechanisms.