The Zaporizhzhya Nuclear Power Plant (ZNPP) briefly lost all off-site power on 8 August, the third such loss in a week, underscoring the fragile nuclear safety and security situation at the site amid the ongoing conflict, IAEA Director General Rafael Mariano Grossi said today.

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The plant lost connection to its only remaining off-site power line, the 330 kilovolt (kV) Ferosplavna-1 line, prompting all available emergency diesel generators to automatically start up and power the plant's vital safety systems. 

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It was the 25th complete loss of off-site power (LOOP) at the ZNPP since the start of the conflict, and the 13th since April.

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The ZNPP’s main 750 kV Dniprovska power line has remained unavailable since March, when the line was damaged. Although repairs to the Dniprovska line were successfully completed during the sixth Agency-negotiated ceasefire in June 2026, the line could not be re-energized due to extensive damage at an associated electrical substation located more than 100 kilometres north-west of the plant. Consequently, the ZNPP continues to rely on the single Ferosplavna-1 off-site line, a situation that has contributed to repeated LOOP events.  Before the military conflict, the plant had ten off-site power lines.

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“The increasing frequency of power losses at the plant is deeply concerning. A reliable connection to the electricity grid remains essential for nuclear safety and security,” Director General Grossi said.

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Later on 8 August, at around 14:30 local time, there was a brief voltage drop on the 330 kV Ferosplavna-1 line, which led to the disconnection of the interconnection line between the 330 kV Zaporizhzhya Thermal Power Plant switchyard and the main autotransformer in the 750 kV ZNPP open switchyard. The plant’s power system reportedly switched automatically, drawing electricity from the 330 kV switchyard to supply the back-up transformers. Although the IAEA team at the site did not observe the activation of emergency diesel generators, it is following up with the plant to assess the response of the plant’s systems to the grid event.

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As reported in last week’s update, due to the prolonged unavailability of the 750 kV Dniprovska line and continuing difficulties in resupplying the site’s diesel fuel stores because of military activity in the area, the ZNPP decided to increase the water levels in the spent fuel pools of all six reactor units.

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Over the past week, the IAEA team at the site has observed this measure being implemented at all six units. By raising the water levels in the spent fuel pools, the site is increasing the time available before water could begin to boil and thereby strengthening safety margins in the unlikely event of an extended LOOP event during which diesel fuel supplies were exhausted and cooling could not be maintained.

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“This is a prudent step to strengthen safety margins and prepare for unlikely but potentially critical scenarios. At the same time, it does not reduce the urgent need for reliable off-site power and full respect for the IAEA’s Five Concrete Principles for protecting the plant,” Director General Grossi said.

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The IAEA team at the ZNPP continued to hear military activity, including explosions, several times a day, often at distances that appeared to be close to the site. The plant also continued to report military activity in the nearby city of Enerhodar, where many plant staff live, as well as drone activity in and around the site.

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Elsewhere in Ukraine, nuclear sites continued to report air raid alarms and drone activity. The South Ukraine Nuclear Power Plant (SUNPP) reported air raid alarms on a near daily basis and detected two drones within its monitoring area late last week. The Chornobyl Nuclear Power Plant also reported air raid alarms on a near daily basis, with a noticeable increase over the weekend, when the site reported detecting two drones within its monitoring area.

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The IAEA also continued its comprehensive programme of assistance to Ukraine, delivering equipment to help address nuclear safety and security needs at facilities across the country.

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Recent deliveries included primary healthcare and emergency medical equipment, diagnostic devices, patient support equipment and associated consumables for the Centre of Primary Health Care in Slavutych; one ventilator for a hospital supporting the SUNPP; eight alpha detectors for SSE Ecocentre; and protective masks and gas filters for the Rivne Nuclear Power Plant.

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These deliveries were made possible with funding from Canada, the Czech Republic, Japan and Sweden.

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Text Courtesy, IAEA