The city where most staff of Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) live was left without electricity for 16 hours over the weekend after a second sub-station in the area sustained damage and was taken out of operation, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.
The IAEA team of experts stationed at the ZNPP on Saturday visited the site of the latest affected sub-station, Raduga, in the city of Enerhodar to observe damage to one of its two transformers that the plant said was caused by a drone attack the previous evening.
Coming just a few days after one of Enerhodar's other sub-stations - Luch - was destroyed, Director General Grossi said it further deepened his serious concerns about the fragility and vulnerability of Ukraine's electricity infrastructure, which is crucial also for nuclear safety and security, even though the power supplies to the ZNPP's six reactors were not affected this time.
As a result of recent days' damage to the electrical infrastructure, the IAEA was informed that Enerhodar had no electricity from around 8pm on Friday to noon on Saturday, when power was restored in the city, which is located next to the ZNPP. Sub-stations form vital parts of a country's electrical production, transmission and distribution system.
"Whoever is behind this, it must stop. Drone usage against the plant and its vicinity is becoming increasingly more frequent. This is completely unacceptable and it runs counter to the safety pillars and concrete principles which have been accepted unanimously.," Director General Grossi said.
After Wednesday's destruction of the Luch sub-station - which had provided electricity to parts of Enerhodar and other areas - the Raduga sub-station was used to supply some of the lost power to five districts of Enerhodar, before it too was damaged.
Two days after visiting Enerhodar to assess the extent of damage to the Luch sub-station, the IAEA experts yesterday saw electric components and other drone debris at the Raduga sub-station, as well as an unexploded device on the ground near the damaged transformer.
Officials at the scene said a hole in the transformer had caused a cooling oil leak that prompted the sub-station to shut down. They added that the oil spill had been covered by sand and that repairs were under way, which were completed later in the afternoon. The IAEA experts did not see any oil traces on the transformer itself. The sub-station appeared to have suffered less damage than the transformer at the Luch sub-station and there was no fire or firefighters in the area.
The ZNPP later informed the IAEA team that power for Enerhodar had been restored on Saturday afternoon by using Raduga's back-up transformer.
As was the case with the damage to the Luch sub-station, the loss of electricity from Raduga did not directly impact the two power lines that are still available for the ZNPP. The plant continues to receive the off-site electricity it needs for cooling its shutdown reactors from its last remaining 750 kilovolt (kV) main power line and the last 330 kV backup power line.
However, the failure of the Raduga sub-station affected the electrical supply to the industrial zone next to the ZNPP as well as the plant's transport unit, a pump for its tap water and some of the area's external environmental radiological monitoring stations, which stopped working briefly on Saturday morning after running out of battery, but resumed operating as expected when power was restored.
