Mr. Grossi and his delegation are expected to arrive at the site in the morning and leave in the afternoon, according to the Tass agency citing an official of the Russian operator Rosenergoatom.

This is Grossi's second visit to Zaporizhzhia, Europe's largest nuclear power plant, since the conflict began in February 2022.

Arriving in Ukraine earlier this week, the IAEA chief will have to cross the front line to enter Russian-controlled facilities.

The IAEA has had a team of experts inside the plant since September 2022. Mr. Grossi has been consulting for several months with Kiev and Moscow to set up a protection zone around the site, which has been regularly hit by strikes and repeatedly affected by power cuts.

Ukraine, for its part, believes that only a withdrawal of the Russian army and personnel from the plant would guarantee nuclear safety. As for Russia, it accuses Kiev of wanting to take back the site by force.

IAEA Director Rafael Grossi (center) inspects the damage to the Zaporizhzhia nuclear power plant in Ukraine during his previous visit on September 1, 2022 © Fredrik DAHL/International Atomic Energy Agency (IAEA)/AFP/Archives

On 22 March, Mr Grossi warned that the plant was in a "precarious state". According to the IAEA, the "last emergency power line", damaged since March 1, remains "disconnected and under repair". As a last resort, it ensures nuclear safety and security in Zaporojjia, in particular by cooling its reactors.

"Playing with fire"

The plant depends on electricity supplied by a single 750 kV main external line, and any damage (on that line) will result in the total loss of all offsite power to the plant, according to the IAEA.

On March 9, the gigantic power plant was cut off from the Ukrainian power grid for 11 hours after a Russian strike. Emergency diesel generators had been switched on to ensure minimal power to safety systems, according to Ukrainian operator Energoatom, which had warned of the risk of a nuclear accident.

IAEA Director Rafael Grossi (L) and Ukrainian President Volodymyr Zelensky on March 27, 2023 in Dnipro, Ukraine © Handout / UKRAINIAN PRESIDENTIAL PRESS SERVICE/AFP

"We are playing with fire," warned Mr. Grossi.

The head of EU diplomacy Josep Borell said that "Russia is endangering the security of the entire European continent, including Russia."

Electricity is essential to run the pumps that circulate water. Because it is necessary to constantly cool the fuel of the reactor cores as well as that placed in the storage pools, to avoid a meltdown accident and radioactive releases into the environment, in a scenario identical to that of Fukushima in Japan after the tsunami of March 2011.

Rafael Grossi and Ukrainian President Volodymyr Zelensky had already visited together on Monday a hydroelectric station in the Zaporizhzhia region, responsible for supplying power to the nuclear power plant.

The Ukrainian army recorded 18 Russian air raids, three missile strikes and 50 multiple rocket attacks for the day on Tuesday, the General Staff said Wednesday morning.

Russia has also revived the rhetoric of threats against Sweden and Finland, candidates for NATO membership, with a diplomat saying these countries would become "legitimate targets".

"After the accession of Finland and Sweden, the total length of the borders between Russia and NATO will almost double," Ambassador Viktor Tatarintsev said in a text posted on the website of the Russian mission in Sweden.

Ukrainian army fires at Russian positions near Bakhmut, March 20, 2023 © Aris Messinis / AFP/Archives

"If it still seems to anyone that this will somehow improve Europe's security, rest assured that the new members of the hostile bloc will become a legitimate target for Russian retaliatory measures, including those of a military nature," the diplomat warned.

The candidacies of Finland and Sweden, which are turning the page on decades of neutrality and then out of military alliances, are a direct consequence of the Russian invasion of Ukraine.

© 2023 AFP