The UN's nuclear watchdog is "making progress" on inspecting several parts of the Zaporizhzhia nuclear plant in Ukraine after claims it had been mined, the head of the International Atomic Energy Agency (IAEA)  Rafael Grossi said Friday.Ukraine and Russia have accused each other of planning a provocation at the site, raising alarm over risks of a radioactive disaster at Europe's largest nuclear plant.Earlier this week, Grossi said the watchdog had requested access to the rooftops of two reactor units, as well as parts of the turbine halls and cooling systems."I think we are making progress," he said Friday in Tokyo."We have been able to complete the tours of the cooling ponds and other places,"  Grossi said, adding they had "not seen any indications of explosives or mines."He noted that IAEA officials had not yet been able to visit the facility's rooftops."I'm pretty confident that we will get this authorization," Grossi added."This is a combat zone, it's an active warzone, so sometimes it may take a day or two to get the authorizations."On Tuesday, Kyiv accused Moscow of planning "dangerous provocations" at the site, while Russia has accused Ukraine of similar plans.The Ukrainian military claimed that "external objects similar to explosive devices were placed on the outer roof of the third and fourth reactors" at the site.Fears over the plant have persisted throughout the war in Ukraine and have been exacerbated by the destruction of the Kakhovka dam — which provided cooling water for the plant.Grossi said the IAEA had contingency plans for various scenarios at the plant and "we do have a clear assessment of what emergency preparedness and response mechanisms should be in place should something occur."