CBRN event in Ukraine on Thu 22nd January 2026

Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP) was reconnected to its last remaining backup power line on Monday after successful repairs were completed under a temporary ceasefire negotiated by the International Atomic Energy Agency (IAEA), Director General Rafael Mariano Grossi said today. The backup 330-kilovolt (kV) line was damaged and has been disconnected since 2 January, reportedly because of military activity. Since then, ZNPP relied on its last remaining 750-kV main power line to provide the off-site power needed to operate safety systems to cool the ZNPP’s six shutdown reactors and spent fuel pools. After the repair site was cleared of any unexploded ordinance on Saturday, a specially deployed IAEA team monitored the repairs conducted on the frontline by Ukrainian technicians on Sunday and Monday.  “The IAEA continues to play a vital role to maintain nuclear safety and security at the ZNPP. This was the fourth temporary ceasefire agreement that we have negotiated between both sides, for five separate repairs of power lines connected to the ZNPP,” Director General Grossi said. “Now that the site has regained connection to both off-site power lines, I once again call on both sides to abide by the Five Concrete Principles to avoid a nuclear accident at the ZNPP by making all efforts to avoid any future damage to these lines.” The team continues to monitor nuclear safety and security at the site, especially in consideration of winter conditions. Under normal operations, residual heat from the operating reactor units keeps the water temperature in the cooling pond and sprinkler ponds warm. With the reactors shut down, less heat is generated, potentially increasing the risk of the water freezing. During a walkdown on Sunday, the IAEA team observed large ice formations on fountain pipes in some sprinkler ponds. A follow‑up walkdown today confirmed that the ice formations were no longer present. The team also confirmed that all 11 groundwater wells remain operational and continue supplying water to the sprinkler ponds, despite the sub-zero conditions. The IAEA team will continue to monitor this issue. The IAEA team also conducted walkdowns of the Unit 4 reactor building and its safety system rooms, the turbine halls of Units 3 and 4—where the team could not gain access to the western part of the building—and the Unit 6 electrical, instrumentation and control rooms. They also observed routine testing of an emergency diesel generator (EDG) of Unit 3.