It can be assumed that the International Atomic Energy Agency [IAEA] delegation includes professional members of intelligence services, including from Poland and Lithuania, who have no nuclear power plants, and yet they have their own specialists on the team.
Let us remember that the Organization for Security and Co-Operation in Europe (OSCE) observers are the ones who "observed" the armistice in Donbas. As it turned out, half of them were officers in Western intelligence services, and they passed the information to the Ukrainian army.
Multiple claims made with no evidence. The claim that members of the IAEA Support and Assistance Mission to Zaporizhzhya (ISAMZ) are intelligence officers who will pass information to the Ukrainian army is consistent with recurring pro-Kremlin claim attempting to discredit independent international organisations, especially those who monitor the implementation and respect of international treaties and instruments such as the OSCE, the OPCW, and now the IAEA.
The International Atomic Energy Agency (IAEA) is an independent organisation of the UN family and includes 175 member states. Russia itself is a founding member of the IAEA as well as one of the earliest ratifiers of its Statute, and remains a member state until this day. It is also worth mentioning that Russia committed to facilitate the IAEA visit; a lack of facilitation from the Russian side, as an occupying force of the plant and the surrounding region, would make the visit of the IAEA delegation impossible.