COPPELION

2036. Tokyo, ravished by radioactive contamination caused by a nuclear power-plant accident, is now in lockdown. COPPELION—a special unit of Japan's Ground Self-Defense Forces' 3rd Division made up of three high school girls genetically engineered to be impervious to radioactivity—is sent in to search for survivors in Tokyo, a.k.a. "The City of Death." (Source: Kodansha USA) — Description from AniList community (anilist.co).