Other than a scorched administrative building, the vast complex in southern Ukraine -- Europe's largest nuclear power plant -- appeared largely untouched by the clashes during a visit by AFP this weekend, part of a press tour organised by the Russian military.

There has been deep international concern over the situation at the plant, which has six of Ukraine's 15 reactors and can create enough energy for four million homes.

Russian forces seized the site amid fighting in early March that caused a large fire at a training facility at the plant, which sits along the Dnipro river south of the Ukrainian-held city of Zaporizhzhia.

There was no spike in radiation, but the clashes nonetheless caused deep worries, especially in the country that was the site of the world's worst nuclear accident at Chernobyl in 1986.

Rafael Grossi, the head of the UN's nuclear watchdog, the International Atomic Energy Agency, said last week that it was "extremely important" for IAEA monitors to be able to access the site, which was built in the early 1980s but modernised in recent years.

Russia insists it is taking all necessary precautions at the plant, where its troops now patrol in the shadows of its enormous and heavily reinforced red-domed reactors.

- 'Everything is good!' -

"The Zaporizhzhia NPP is operating normally, in compliance with all nuclear, radiation and environmental safety standards," Valery Vasilyev, a major general with Russia's Nuclear, Biological and Chemical Protection Troops, told journalists at the site.

The facade of the training centre that caught fire remains blackened and its windows were blown out, but no other signs of damage at the plant were visible.

Soldiers on patrol or positioned behind sandbags showed no sign of concern and wore no protective equipment against radiation.

"Everything here is good!" Andrey Shevchik, the new pro-Russian mayor of Energodar, the city of around 50,000 people built in the 1970s to serve local power plants, told journalists at the site.

"Residents and workers of the nuclear power plant are completely safe," he said.

"All comfortable conditions are being created for them to work, to generate energy, and to keep the nuclear power plant safe."

Shevchik said the plant was "ready to sell electricity to Europe", before driving off in a gleaming SUV painted with Russian flags.

He also said residents who had fled were returning to the city, though there was no way to verify the claim.

It is unclear how exactly the plant is now operating, though Ukrainian workers continue to work on site under Russian supervision.

AFP was unable to meet any of the Ukrainian staff at the plant or to speak to residents in Energodar.