Zaporizhzhia ‘extremely fragile’ relying on single off-site power line, IAEA warns
Europe’s largest nuclear power plant has just one remaining power line for essential nuclear safety and security functions, compared with its original 10 functional lines before the military conflict with Russia, warned Rafael Mariano Grossi, director general of the International Atomic Energy Agency.
The off-site power situation at the six-reactor Zaporizhzhia nuclear power plant in Ukraine is “extremely fragile,” Grossi said, since its last 330-kilovolt backup line has remained disconnected since the plant lost access to it on May 7. It is unclear when it will be restored.
As a result, Zaporizhzhia is entirely dependent on the last remaining 750-kV line for the external electricity required to operate the plant's nuclear safety systems and cool its nuclear fuel.
After Russia took control of Zaporizhzhia in early 2022, the plant has lost all access to off-site power eight times, but it was usually restored within a day, according to the IAEA.
Quotable: “We are actively engaged. I have been discussing with the [energy] minister, with the Ukrainian regulator, and also, of course, with the Russian side, because they are in control of the plant. The idea is to be talking to everybody when it comes to safety,” Grossi said during a press conference Tuesday during his visit to Kyiv, Ukraine.
Grossi warned that even though Zaporizhzhia has not been operating for some three years now, its reactor cores and spent nuclear fuel still require continuous cooling, for which electricity is needed to run the water pumps.
“There are only two [power lines] in operation—one 750-kV and another 330-kV—which are intermittently down because of a number of situations... attacks or interruptions, we do not know,” Grossi added in his remarks. “The repair works have been performed but what we expect is this quite unpredictable situation will continue.”
“We have to move to a more stable situation, and this, of course, depends on overall political negotiation, which will lead to less—or, ideally, no—military activity around the plant.” Grossi said. “Absent that, what we are doing [and] what everyone is doing is (trying) to avoid the worst (and) repair it as soon as possible. Try to ensure outside power supply whenever it falls down.” Grossi plans to visit Russia as part of his regular contacts with both sides to ensure nuclear safety and security during the conflict.
A closer look: In addition to the lack of off-site power backup, on May 22 the IAEA reported a drone strike at Zaporizhzhia’s training center—the third such incident so far this year. There were no casualties or major damage; however, one person died in April 2024 when a drone struck the plant’s main containment building.
Ukraine blames Russia for the strikes, but Russia has denied responsibility.
The Zaporizhzhia-based IAEA team continues to monitor and assess other aspects of nuclear safety and security at the plant. They conducted a walkdown last week to measure and confirm stable levels of cooling water in the site’s 12 sprinkler ponds and visiting its two fresh fuel storage facilities, where no nuclear safety or security issues were observed.
The IAEA team has reported hearing military activities on most days over the past week, at different distances away from the power plant, Grossi said.
At Ukraine’s three operating nuclear plants—Khmelnytskyi, Rivne and South Ukraine—three of the nine total reactors are in planned outage for refueling and maintenance.
IAEA team members at these sites also continue to hear military activities nearby. At South Ukraine, the IAEA team saw a drone being shot at by antiaircraft fire on May 23, and plant workers reported that 10 drones were observed 2.5 kilometers (about 1.55 miles) south of the site the same evening. Also on May 23, Chernobyl workers saw two drones flying just a few miles from the site. And the IAEA team at the Khmelnytskyi plant was required to shelter on-site last Monday.
