Power restored to ZNPP

The Zaporizhia NPP (ZNPP) is again receiving external power after a month-long outage, following repairs carried out under the protection of a local ceasefire negotiated by the International Atomic Energy Agency (IAEA) and observed by its teams on the ground.

“Today is a rare, good day for nuclear safety and security in Ukraine and beyond, although the overall situation of course remains highly precarious,” said IAEA Director General Rafael Grossi. “After exactly one month without any off-site power, the Zaporizhzhya Nuclear Power Plant is once again receiving the external electricity it needs to cool its six reactors and spent fuel.”

He added: “Since the plant was disconnected from its last off-site power line on 23 September, we have been working intensively with the Russian Federation and Ukraine to create the necessary security conditions for repairs to be carried out on both sides of the frontline. Despite the war, they both agreed that it was vital to restore off-site power and cooperated constructively with us to make that happen,” he said.

In the reconnection process followed by an IAEA team on the ground and from the ZNPP’s electrical control room, the newly repaired 750 kilovolt (kV) Dneprovskaya power line was energised by the Ukrainian grid operator at and the ZNPP 750kV switchyard was fully powered two minutes later. The ZNPP then began gradually restoring power to its six reactor units and the remainder of the site.

After off-site power was restored to the whole ZNPP site, the last of the emergency diesel generators that had supplied back-up power for 30 days was turned off. This ended the tenth and by far the longest complete loss of off-site power suffered by the plant during the conflict.

“What was once virtually unimaginable – a nuclear power plant regularly losing off-site power – has unfortunately become a common occurrence during this devastating war. However, this was the most challenging loss of power event we have experienced so far. I would especially like to extend my thanks to the technicians – on both sides of the frontline – who have been working hard in recent days to restore power in very difficult circumstances,” Grossi said.

Work is now underway repair the 330 kV Ferosplavna-1 back-up line which has been offline since May. Work on both lines followed the establishment of temporary ceasefire zones on opposite sides of the Dnipro River. As both zones are in an active combat area, de-mining specialists conducted extensive clearance work before the repairs could begin.

The IAEA team based at the ZNPP monitored the work at the damaged section of the Dniprovska line, where technicians replaced several broken cables before re-attaching them to the transmission towers. A damaged metal support arm of one transmission tower was also replaced, and new insulators were installed in several towers.

The IAEA is continuing to coordinate with both sides to pave the way for further repairs of the Ferosplavna-1 line, where additional damage outside the ceasefire zone was identified. The IAEA was informed that two broken transmission cables were found 1.8 km from the electrical switchyard of the Zaporizhia Thermal Power Plant, located near the ZNPP.

Before the conflict, the ZNPP had access to ten power lines. In recent years, that was reduced to two. Although the plant’s six reactors have not produced electricity for more than three years and have been shut down, they still require power to run their cooling pumps and for other nuclear safety and security equipment. Over the past month, the plant has relied on emergency diesel generators for the electricity it needs.

ZNPP confirmed that power supply to the plant had been resumed. “The Zaporizhia Nuclear Power Plant has resumed electricity supply for the plant’s own needs. The Dneprovskaya high-voltage power transmission line has been put back into operation after repairs,” the statement said.

“The previous 30 days, during which ZNPP operated solely on backup diesel generators in the absence of external power supply, were an unprecedented event in the history of global nuclear energy. No other nuclear power plant in the world has ever been in such conditions for such a long period” the statement said.

ZNPP Communications Director Yevgeniya Yashina, noted that, since this is not the first time the plant had lost power during the conflict, the actions of the personnel were clear and well-rehearsed, and the fuel supply plans had been developed in advance.

“In general, we were ready for this development, but of course, it was still unpleasant… The plant is now operating normally, and we are finally receiving electricity from outside. We turned off the diesel generators, which we had been using. All the plant’s units are functioning properly, and the staff is working according to their schedule. Everything is fine at the plant.”

The radiation situation at the plant site is normal after reconnection of the high-voltage power line. This was reported by the Don Interregional Territorial Department for Nuclear Radiation Safety Supervision of Russian nuclear regulator Rostekhnadzor.

The Russian Foreign Ministry said that Ukraine has given security guarantee, which were necessary to restore external power supply to the plant. The ministry stressed that the agreements were reached after “long and difficult consultations”.

According to military and diplomatic sources widely cited by Russian media, the Ukrainian leadership gave direct security guarantees, effectively acknowledging that it cannot control the risks associated with shelling near the nuclear facility. The sources speculated that this may mean an end to Ukrainian attacks on ZNPP. According to diplomatic sources, Russia intends to use the guarantees it has received to carry out restoration work and reconnect the plant to a stable power supply. The Foreign Ministry has emphasised that the safety of the ZNPP staff and facilities will remain an absolute priority.