The unveiling of the “nucleus of Cesium 137”

Head of Iran's Atomic Energy Organization Mohammad Eslami during the unveiling ceremony of the "nucleus of Cesium 137" in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)

Head of Iran's Atomic Energy Organization Mohammad Eslami looks on during the unveiling ceremony of the "nucleus of Cesium 137" in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)

The "nucleus of Cesium 137" is seen during an unveiling ceremony in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)

The "nucleus of Cesium 137" is seen during an unveiling ceremony in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)

Head of Iran's Atomic Energy Organization Mohammad Eslami looks on during a news conference in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)

Head of Iran's Atomic Energy Organization Mohammad Eslami speaks on during a news conference in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)

Head of Iran's Atomic Energy Organization Mohammad Eslami speaks on during a news conference in Tehran, Iran August 27, 2023. Majid Asgaripour/WANA (West Asia News Agency)