Loss of Off-site power for ZNPP

8/25/2022

Ukraine has informed the International Atomic Energy Agency (IAEA) that the country’s Zaporizhzhya Nuclear Power Plant (ZNPP) today temporarily lost connection to its last remaining operational 750 kilovolt (kV) external power line, Director General Rafael Mariano Grossi said, further underlining the urgent need for an IAEA expert mission to travel to the facility.

Ukraine told the IAEA that the ZNPP, Europe’s largest nuclear power plant, at least twice lost connection to the power line during the day but that it was currently up again. It said the ZNPP remained connected to a 330 kV line from the nearby thermal power facility that can provide back-up electricity if needed.

Ukraine also informed the IAEA that as a result of the cuts in the 750 kV power line, the ZNPP’s two operating reactor units were disconnected from the electricity grid and their emergency protection systems were triggered, while all safety systems remained operational, the Director General said. All six units remained disconnected from the grid also after the power line was restored, Ukraine said.

There was no information immediately available on the direct cause of the power cuts. The six-reactor ZNPP normally has four external power lines, but three of them were lost earlier during the conflict. The IAEA remains in close contact with Ukraine and will provide updated information as soon as it becomes available.

A secure off-site power supply from the grid is essential for ensuring nuclear safety. This requirement is among the seven indispensable nuclear safety and security pillars that the Director General outlined at the beginning of the conflict. In the case of a loss of external power, the ZNPP – like other nuclear power plants around the world – still has diesel generators available to provide back-up power.

https://www.iaea.org/newscenter/pressreleases/update-94-iaea…

This is a dangerous situation.

Jaak

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8/27/2022 NYT

KYIV, Ukraine — Ukraine’s largest nuclear power plant came under renewed shelling on Saturday as fraught negotiations to allow for a team of scientists from the International Atomic Energy Agency to visit the facility took on added urgency.

The United Nation’s nuclear watchdog has assembled a team of experts to visit the Zaporizhzhia Nuclear Power Plant in southeastern Ukraine — Europe’s largest nuclear power station — as early as next week.

A list of the team’s members seen by The New York Times includes the nuclear agency’s chief, Rafael Mariano Grossi of Argentina, and 13 other experts from mostly neutral countries. Neither the United States nor Britain, countries that Russia scorns as unfairly biased because of their strong support for Ukraine, is represented.

https://www.nytimes.com/live/2022/08/27/world/ukraine-russia…

Jaak