Why did Russia inform the IAEA about taking control of the territory around the Zaporizhzhia nuclear station two days before attacking it?

On March 2:

Russia has informed the International Atomic Energy Agency (IAEA) that its military forces have taken control of the territory around Ukraine’s Zaporizhzhia Nuclear Power Plant (NPP), Director General Rafael Mariano Grossi said today.

What are the legal {requirements and implications} of making this report? Did it mean that Russia was taking responsibility for security there on March 2?