The International Atomic Energy Agency warned that more fighting near the site could run "the very real risk" after Russia was accused of shelling Europe's largest nuclear power plant in southernUkraine.
Russia fired rockets at the Zaporizhzhia nuclear plant and the nearby town of Enerhodar on Saturday night, as Russian forces appeared to strike near the site's dry storage facility.
The power authority said that detecting and responding to any radiation leak from the spent fuel storage was currently impossible.
A power plant employee was hospitalized with injuries.
Ukrainian President Volodymyr Zelensky suggested on Sunday that the international community should impose sanctions on the Russian nuclear industry.
Russia blamed Ukrainian forces for the shelling of the Zaporizhzhia site on Friday.
The attacks on the nuclear power plant could have potentially catastrophic consequences and pose a threat to the environment and public health beyond Ukraine, according to the general director of the IAEA. The U.S. embassy in Ukraine called it a war crime when the Russian military took over Zaporizhzhia in March. According to Ukraine, the power plant's six reactor remained undamaged, but an NPR analysis found the shelling came close to damaging the reactor. The Institute for the Study of War said last week that Russian forces may be using the plant to play on Western fears of a nuclear disaster in Ukraine.
Grossi said that military action jeopardizes the safety and security of the Zaporizhzya nuclear power plant.