Your guess is as good as mine. But if you have watched Russ TV, they aren't afraid of saying the most ridiculous things.

Though according to the article: Renat Karchaa, an adviser to the head of Rosenergoatom, which operates Russia’s nuclear network, said Ukraine planned to drop ammunition laced with nuclear waste transported from another of the country’s five nuclear stations on the plant.

“Under cover of darkness overnight on 5 July the Ukrainian military will try to attack the Zaporizhzhia station using long-range precision equipment and kamikaze attack drones,” Russian news agencies quoted Karchaa as telling Russian television. He offered no evidence in support of the allegation."