Ukraine Has 15 Reactors — 6 of Them at a Seized Power Plant

Energoatom, the state-owned company that operates Ukraine’s nuclear power plants, states on its own “About us” page that it operates 15 reactors across four nuclear power plants. The four sites — Zaporizhzhia, Rivne, South Ukraine, and Khmelnytskyi — have a combined installed capacity of 13,835 megawatts.

However, 6 of these 15 reactors are at the Zaporizhzhia Nuclear Power Plant, which has been under the control of Russian forces since March 2022. According to the International Atomic Energy Agency (IAEA), this plant has been shut down since September 2022. The reactors actually generating Ukraine’s electricity now are the 9 at the remaining three sites.

The Four Plants and the Breakdown of the 15 Reactors

Compiling the number of reactors from Energoatom’s page for each plant gives the following. The reactor type is known as VVER: 13 are VVER-1000 and 2 are VVER-440.

The Zaporizhzhia plant is one Energoatom describes as “the largest nuclear power plant in Ukraine and Europe,” and is said to have generated more than 1.1 trillion kilowatt-hours cumulatively since it began operating. This one site alone held 6 of the 15 reactors — 40% of the total.

Before the Full-Scale Invasion, Half of Electricity Was Nuclear

According to a report the International Energy Agency (IEA) published in September 2024, before Russia’s full-scale invasion in 2022, half of Ukraine’s electricity was generated by nuclear power. Coal-fired power followed at 23%, gas-fired power at 9%, and renewables at 11%. The same report states that the Zaporizhzhia plant’s 6,000 megawatts accounted for about a quarter of Ukraine’s electricity supply before the invasion.

The IAEA’s reactor database (PRIS) page for Ukraine also shows a nuclear share of 55% and nuclear generation of 81,126 gigawatt-hours. However, these figures are for 2021. As of September 2026, this 2021 figure was still the most recent generation and share figure shown on PRIS’s Ukraine page.

Since March 4, 2022, the Zaporizhzhia Plant Has Been Under Russian Control

The IAEA records that two nuclear facilities came under the control of Russian forces after Russia’s full-scale invasion. One was the site of the Chornobyl Nuclear Power Plant, from February 24 to March 31, 2022. The other is the Zaporizhzhia Nuclear Power Plant, which has been under the control of the Russian Federation since March 4, 2022, and remains so today. The IAEA keeps staff stationed at all five of Ukraine’s nuclear power plant sites, including Zaporizhzhia.

Even a shut-down reactor needs electricity, because the pumps that cool the fuel and the spent fuel pools must keep running. According to an IAEA announcement in September 2026, the Zaporizhzhia plant lost its connection to its one remaining external power line — the 330-kilovolt Ferosplavna-1 line — on August 20, 2026, due to military activity north of the Dnipro River. This was the 26th time it had lost external power since the full-scale invasion began, and the 10th time since June alone.

For about three weeks after that, the plant kept its 6 reactors and spent fuel pools cooled using emergency diesel generators. To conserve fuel, it reduced the number of generators running from 4 to 2 and ran the cooling pumps intermittently, the IAEA reports. Under a seventh local ceasefire brokered by the IAEA, mine clearance and repairs were carried out from September 5 to 7, and the power line was reconnected. IAEA Director General Grossi stated that fuel for the emergency generators had nearly run out, and that urgent measures, including bringing in additional fuel, were still needed.

At the same time, the IAEA explains that, because the reactors have been shut down for a long time, the decay heat that needs to be removed is far lower than for an operating reactor, and the time before fuel damage would occur if all power were lost is considerably longer. Even so, it states, such a situation must still be prevented.

Regarding the 70th IAEA General Conference held in Vienna in September, Energoatom reports that a resolution on Ukraine’s nuclear safety submitted by Canada was adopted with 63 votes in favor, calling for the withdrawal of unauthorized Russian military personnel from the Zaporizhzhia plant.

How Much Electricity Are the 9 Reactors Producing?

In an October 2025 analysis, the IEA writes that Ukraine’s electricity remains heavily dependent on “the three remaining operating nuclear power plants.” These three sites, in the west and center of the country, account for 7.7 million kilowatts, or 50% of the country’s power generation capacity, it states.

According to Energoatom’s announcement of March 18, 2026, its nuclear power plants generated 54.1 billion kilowatt-hours of electricity in 2025, 100.8% of plan. It states this was an increase over 2024.

Compared with the 2021 figure of 81,126 gigawatt-hours (81.1 billion kilowatt-hours) in PRIS, the 2025 generation is roughly two-thirds. However, the 2021 figure is a value reported to PRIS by the country, and the 2025 figure is from Energoatom’s own announcement — the sources differ. No figure confirmable in official statistics could be found for nuclear power’s share of Ukraine’s total generation since 2022. Energoatom states in its company introduction that it “meets 55% of Ukraine’s electricity demand, and 70% in autumn and winter,” but does not indicate which year this figure is for.

The war also reaches the three operating plants. In September 2026, the IAEA reported that drones had been repeatedly detected in the surveillance zones around the South Ukraine, Khmelnytskyi, and Rivne plants and the Chornobyl site. The IEA’s 2024 report points out that damage to a substation near a nuclear plant can prevent a reactor from sending electricity to the grid, or threaten the external power supply that keeps a reactor safe. Attacks on power plants and the restoration of the grid are covered in In a Country Where Power Plants Keep Being Targeted, Generating Electricity in Small, Scattered Pieces.

Where the Fuel Comes From, and the Reactors Under Construction

Energoatom’s introduction to its plants positions the South Ukraine plant as the pioneer in diversifying nuclear fuel supply. It was the first plant in the country to load fuel made by the U.S. company Westinghouse, with Unit 3 running solely on Westinghouse fuel since 2018 and Unit 2 since 2020. At the Rivne plant, the use of Westinghouse fuel began in a VVER-1000 in 2022 and in a VVER-440 as well in 2023.

There are also plans for new reactors. PRIS classifies Ukraine’s reactors as 15 “operational” (13,107 megawatts net output), 2 “under construction” (2,070 megawatts), and 4 “permanent shutdown” (3,515 megawatts). The Khmelnytskyi plant was originally planned to have 4 units, and Energoatom lists construction of new reactors there as one of the plant’s priorities. At the Rivne plant, it has announced a plan for a Unit 5 using the U.S.-designed AP1000. The completion date for either project cannot be determined from the materials for this article.

One thing to note is that the 15 reactors PRIS counts as “operational” include Zaporizhzhia’s 6. On paper, Ukraine’s reactor count remains 15, but only 9 are sending electricity to Ukraine’s grid. When looking at these figures, it is necessary to check by what standard the 15 is being counted.

The Different Ways of Counting, in Table Form

Nuclear power has remained a pillar of Ukraine’s electricity both before and after the full-scale invasion. What has changed is that 6 of the 15 reactors now sit in a place cut off from the country’s own grid.