IAEA mandate doesn’t allow it to name forces shelling Zaporozhye, Kursk plants — official
Disclaimer: TASS is Russian government propaganda, and not a reliable news source.
According to IAEA Deputy Director-General Mikhail Chudakov, the second reason is that Rafael Grossi is a diplomat, a UN diplomat, a Western diplomat, and he will never name the culprits unless there is 100% proof