Counts as any event which results in unsafe levels of radiation leaking from the plant. Can clarify definitions in comments.
@JamesRomeril IAEA has been present on site as recently as this week. So probably from them.
@LachlanMunro This definition seems to at odds with the qualifer "disaster" in the title - some minor theoretically dangerous release is hardly a disaster
@ThomasTwenhoven to clarify, levels somewhere that require people to evacuate or vacate an area, not including plant employees working at the plant.
ISW: "Ukrainian Main Military Intelligence Directorate (GUR) Head Kyrylo Budanov warned on June 23 that Russia has finished preparations for an attack on the Zaporizhzhia Nuclear Power Plant (ZNPP)."
"Budanov stated that Russian forces have mined the ZNPP’s cooling pond and have moved vehicles loaded with explosives to four of the six ZNPP power units."