Worried About Radiation Leaks At Chernobyl, Ukraine Asks Russia To Stop Firing And Authorize Repair Units

Chernobyl nuclear power plant. (Wikimedia Commons/DAVID HOLT)

JAKARTA - Ukraine said there was a danger of a radiation leak at the Chernobyl nuclear power plant after power was cut to the plant on Wednesday, but the United Nations nuclear watchdog saw "no critical impact on safety".

State-owned nuclear company Energoatom said high-voltage power lines had been damaged during fighting between Ukrainian and Russian troops occupying the defunct plant and had been cut off from the national power grid.

It said 'radioactive substances' could eventually be released, threatening other parts of Ukraine and Europe if there was no power to cool spent nuclear fuel stored at the plant that suffered the world's worst nuclear accident in 1986.

Foreign Minister Dmytro Kuleba said a backup diesel generator could power the generator in just 48 hours.

"After that, the cooling system of the spent nuclear fuel storage facility will stop, making radiation leaks imminent," he said on Twitter.

"I call on the international community to urgently demand that Russia stop fire and allow repair units to restore power supplies."

Separately, the International Atomic Energy Agency (IAEA) said on Twitter it was important to ensure a key safety pillar for electricity supply is not interrupted. However, in this case, the IAEA does not see a critical impact on safety.

The IAEA warned on Tuesday that the nuclear materials monitoring system at the radioactive waste facility at Chernobyl had stopped transmitting data.

The Chernobyl plant, which is still radioactive, is located about 100 km (62 miles) from Kyiv. Its fourth reactor exploded in April 1986 during a failed safety test, sending a cloud of radiation over much of Europe.

A nuclear expert with knowledge of generating systems said there was reason to be concerned about the situation, and the key question was how quickly electricity could be restored.

"A power cut to a nuclear facility is potentially very dangerous," said the expert, who declined to be named because he is not authorized to speak publicly about the situation.

"Power outages can cause water in storage facilities to evaporate and spent fuel rods exposed. They can eventually melt and that can cause significant radiation releases," he said.