KYIV, Aug 29 - A U.N. nuclear watchdog team set off on an urgent mission Monday to safeguard the Russian-occupied Zaporizhzhia atomic power plant at the heart of fighting in Ukraine, a long-awaited trip the world hopes will help avoid a radioactive catastrophe.

The stakes couldn’t be higher for the International Atomic Energy Agency experts who will visit the plant in a country where the 1986 Chernobyl disaster spewed radiation throughout the region, shocking the world and intensifying a global push away from nuclear energy.

“Without an exaggeration, this mission will be the hardest in the history of IAEA,” Foreign Minister Dmytro Kuleba said, The Associated Press reported.

Underscoring the urgency, Ukraine and Russia again accused each other of shelling the wider region around the nuclear power plant, Europe’s largest, which was briefly knocked offline last week. The dangers are so high that officials have begun handing out anti-radiation iodine tablets to nearby residents.

To avoid a disaster, IAEA Director-General Rafael Grossi has sought access for months to the Zaporizhzhia plant, which Russian forces have occupied since the early days of the six-month-old war. Ukrainian nuclear workers have been operating the plant.

“The day has come,” Grossi tweeted Monday, adding that the Vienna-based IAEA’s “Support and Assistance Mission ... is now on its way.”

Ukraine’s Foreign Ministry spokesman said the team, which Grossi heads, was scheduled to arrive in Kyiv on Monday. In April, Grossi had headed an IAEA mission to Chernobyl, which Russian forces occupied earlier in the war.

The IAEA said that its team will “undertake urgent safeguards activities,” assess damage, determine the functionality of the plant’s safety and security systems and evaluate the control room staff’s working conditions.

Ukraine’s nuclear energy agency, Energoatom, warned Monday of Russian attempts to cover up their military use of the plant.

“The occupiers, preparing for the arrival of the IAEA mission, increased pressure on the personnel ... to prevent them from disclosing evidence of the occupiers’ crimes at the plant and its use as a military base,” Energoatom said, adding that four plant workers were wounded in Russian shelling of the city where they live.

Ukraine accused Russia of new rocket and artillery strikes at or near the plant, intensifying fears that the fighting could cause a massive radiation leak. So far, radiation levels at the facility, which has six reactors, have been reported to be normal.

Ukraine has alleged that Russia is essentially holding the plant hostage, storing weapons there and launching attacks from around it, while Moscow accuses Ukraine of recklessly firing on the facility.

World leaders have called on the Russians to demilitarize the plant.
Satellite images provided by Maxar Technologies on Monday showed armored personnel carriers on a road near the reactors, damage to a building’s roof also near the reactors, and brush fires burning nearby.

Ukraine reported more Russian shelling in Nikopol, across the Dnieper River from the nuclear power plant, with one person killed and five wounded. Relentless shelling has hit the city for weeks. In Enerhodar, a few kilometers from the plant, the city’s Ukrainian mayor, Dmytro Orlov, blamed Russian shelling for wounding at least 10 residents.

Kuleba, Ukraine’s foreign minister, said in Stockholm that he expects the IAEA mission to produce “a clear statement of facts, of violation of all nuclear, of nuclear safety protocols.” He added, “We know that Russia is putting not only Ukraine, but also the entire world at threat at the risk of nuclear accident.”

In Moscow, Kremlin spokesman Dmitry Peskov said Russia will ensure the IAEA mission’s security, and he called on other countries to “raise pressure on the Ukrainian side to force it to stop threatening the European continent by shelling the territory of the Zaporizhzhia nuclear power plant and surrounding areas.” (ap/ez)