As of 9 March, the Chornobyl nuclear plant site, location of the 1986 accident, was reported to be disconnected from the grid and without a supply of external power.
IAEA director general Rafael Mariano Grossi expressed deep concern about this development as the “secure off-site power supply from the grid for all nuclear sites” was one of seven indispensable pillars of nuclear safety that he had outlined at a meeting of the IAEA’s board of governors on 2 March.
In the case of Chornobyl, however, he said the IAEA agreed with the Ukrainian regulator that its disconnection from the grid would not have a critical impact on essential safety functions at the site, where various radioactive waste management facilities are located.
Specifically the volume of cooling water in the spent fuel cooling pool is sufficient to maintain effective heat removal without a supply of electricity. The site also has emergency diesel generators and batteries.
Nevertheless, the lack of power is likely to lead to a further deterioration of operational radiation safety at the site and create additional stress for around 210 technical staff and guards who have not been able to rotate for the past two weeks, in effect living there around the clock, DG Grossi added. “From day to day, we are seeing a worsening situation at Chornobyl, especially for radiation safety, and for the staff managing the facility under extremely difficult and challenging circumstances,” he said.
In another development, he said the IAEA had lost remote data transmission from its safeguards systems installed to monitor nuclear material at Chornobyl and another Ukrainian nuclear power plant now controlled by Russian invaders, the Zaporizhzhya 6 x 1000 MW VVER (PWR) plant.
The Ukrainian nuclear regulator said eight of the country’s 15 PWRs remained operating, including two at Zaporizhzhya. The Zaporizhzhya site has four 750 kV power lines plus an additional one on standby. Two have been damaged and therefore there were now two power lines, plus the one on standby, available to the plant. The off-site power requirements can be met with one power line and, in addition, there are emergency diesels. “Nevertheless, this is another example of where the safety pillar to secure off-site power supply from the grid for all nuclear sites has been compromised,” DG Grossi said.
In addition, the Zaporizhzhya unit 6 transformer had been taken out of service and was undergoing emergency repair to fix damage inflicted by Russian shelling on ¾ March, which also set fire to the on-site training centre.
Energoatom, the Ukrainian nuclear plant operator, as of 9 March, listed the following on the Zaporizhzhya site: “50 units of heavy equipment, about 400 military men, and lots of explosives and weapons.”