Ukraine has informed the International Atomic Energy Agency (IAEA) that there has been no leak of radioactive material from the country's Zaporizhzhia Nuclear Power Plant (NPP) seized by Russia, the UN atomic agency said Friday.

In a statement published on the IAEA website, director-general Rafael Mariano Grossi said regular staff continues to operate the nuclear power plant.

Located in the city of Enerhodar in southeastern Ukraine, Zaporizhzhia is the largest nuclear power plant in Europe and the ninth-largest in the world. Under normal conditions, it produces one-fifth of the electricity of Ukraine, which relies heavily on nuclear energy from 15 power plants across the country. 

Ukraine's nuclear regulator informed the IAEA that a projectile hit a training building in the vicinity of one of the plant's reactor units last night, causing a localized fire that was later extinguished, the statement said.

Two people were reportedly injured in the incident.

Fortunately, the safety systems of the plant's six reactors had not been affected. There has been no release of radioactive material, the statement said, adding that radiation monitoring systems at the site are fully functional.

Situation remains challenging

However, the operator has reported that the situation remains very challenging. Therefore, it has not yet been possible to access the whole site to assess that all safety systems are fully functional, the IAEA said.

Of the plant's six reactor units, Unit 1 has been shut down for maintenance, Units 2 and 3 have undergone a controlled shut down, Unit 4 is operating at 60 percent power, and Units 5 and 6 are being held "in reserve" in low power mode.

The IAEA Incident and Emergency Centre (IEC) has been put in full response mode due to the events at the Zaporizhzhia NPP, Grossi said. The IEC will be manned around the clock to continuously receive, assess and release information about developments.

The director-general said he remained gravely concerned about the situation at Ukraine’s largest nuclear power plant. The main priority was to ensure the safety and security of the plant, its power supply and the people who operate it, he said. 

"I'm extremely concerned about the situation at the Zaporizhzhia NPP and what happened there during the night. Firing shells in the area of a nuclear power plant violates the fundamental principle that the physical integrity of nuclear facilities must be maintained and kept safe at all time," he said. 

Keeping the normal function of the reactors' cooling system and preventing fuel meltdowns are crucial for not repeating the Chernobyl catastrophe in 1986.

"If there will be an explosion, it will the end to all of us, the end of Europe, the evacuation of Europe," Ukrainian President Volodymyr Zelenskyy said in an appeal to the European Union (EU) in a video.