The Ukrainian troops, upon shelling the Zaporozhye nuclear power plant, tore through the roof of the special building where the fuel for the nuclear reactor is stored, breaking it as a result of the aggression, according to Vladimir Rogov, a member of the main council of the Zaporozhye region military-civil administration. 

"The roof of the special building No. 1 of the Zaporizhzhia NPP has been broken as a result of a strike by [Ukrainian President Volodymyr] Zelenskyy's militants. Fresh fuel for the ZNPP reactors is stored in this building," Rogov wrote. 

The physical damages sustained on the facilities will be assessed by the IAEA mission upon arrival, where they will also determine the operability of the main and backup security and safety systems, according to the organization's statement. 

IAEA Director General Rafael Grossi said on Monday that the IAEA mission is already heading to the ZNPP and will be arriving on site this week. 

"Once reaching Zaporizhzhya later this week, ISAMZ will assess the physical damage to the facilities, determine the functionality of the main and backup safety and security systems, and evaluate the working conditions of the control room staff. At the same time, the mission will undertake urgent safeguards activities to verify that nuclear material is used only for peaceful purposes," the statement says.

Washington, on its part, believes that a controlled shutdown of the Zaporozhye nuclear power plant (ZNPP) reactors will be the most secure option in the short term, according to White House National Security Coordinator for Strategic Communications John Kirby. 

"We continue to believe that a controlled shutdown of the Zaporizhzhia nuclear reactors would be the safest and least risky option in the near term," Kirby said.

On Monday, the Ukrainian Foreign Ministry said that a group of IAEA experts headed by Grossi are going on a mission to ZNPP, arriving later in Kiev in the day.

Read more: Ukrainian forces take revenge on Zaporozhye, shell cities: Official