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

Question

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?

Answer 1

I have read a lot of IAEA documents. I can't recall seeing anything in them that places requirements on an invading army to report unusual conditions. Nearly all of the requirements are on the country or agency operating the reactor.

Countries that operate nuclear reactors are generally required to report anything that could affect the safe operation of their own reactors. It becomes automatic. Somebody makes a mistake in maintenance procedures that is caught by the follow-up check - report to the IAEA. The country's currency fluctuates meaning purchasing nuclear fuel may be difficult - report to the IAEA. It's too dry so the river/lake used for cooling is low - report to the IAEA. It's too wet so the lake is too high possibly making it difficult for workers to safely get to the station - report to the IAEA. The wrong surface-treatment cement sealant is delivered to the station but not used - report to the IAEA. There is labor unrest in the catering industry in the nearby town so workers may not get their cafeteria meals - report to the IAEA.

It becomes a habit.

I'm thinking that Russia is just following routine. They see a nuclear reactor. Something is happening near it. They report it to the IAEA.

Not that the IAEA is likely to be able to do anything about it. In most cases, countries have their own national standards and enforcement agencies. In Ukraine it is the State Nuclear Regulatory Inspectorate of Ukraine. This agency is, understandably, hampered by the invasion.

Answer 2

I'm guessing they were preparing the ground for the narrative that it was the Ukrainians who attacked the power plant. Which is what the Russian MoD said Friday, in fact claiming Russia had been in control of the plant since Feb 28. As AP reports:

West says Russia attacked nuke plant, Russia blames Ukraine [...]

Russia’s U.N. ambassador Vassily Nebenzia rejected claims that its military forces attacked the plant as “simply untrue” and part of “an unprecedented campaign of lies and disinformation against Russia.”

He claimed Russia took control of Enerhodar and the Zaporizhzhia on Feb. 28 and reached agreement with the plant’s management for the Russian military to guard the facility to ensure its security “to prevent the Ukrainian nationalist or other terrorist forces from taking advantage of the current situation to organize a nuclear provocation.”

According to the Russian Ministry of Defense, he said, a Russian mobile patrol in the area adjacent to the plant on Thursday night was attacked by “a Ukrainian sabotage group” with heavy small arms fire from the windows of several floors of a training complex just outside the nuclear plant “in order to provoke return fire.”

The Russians returned fire “and suppressed their fire,” he said, and “as they were leaving, the Ukrainian sabotage group set fire to the training facility.”