By Pavel Polityuk KYIV, Jan 23 (Reuters) - In the midst of extreme cold weather, Russia has intensified its attacks on Ukraine's energy system, which relies almost entirely on electricity produced by
Impact of Russian Attacks on Ukraine's Nuclear Power Infrastructure
Consequences of Attacks on Nuclear Power Substations
By Pavel Polityuk
Importance of Nuclear Power in Ukraine
KYIV, Jan 23 (Reuters) - In the midst of extreme cold weather, Russia has intensified its attacks on Ukraine's energy system, which relies almost entirely on electricity produced by nuclear power plants and has already lost half of its generating capacity.
Current State of Energy Generation
WHAT NUCLEAR POWER PLANTS MEAN FOR UKRAINE
Risks of Targeting Substations
President Volodymyr Zelenskiy has said that Russia intends to deprive Ukraine of this energy by planning to hit substations that supply nuclear power to consumers, plunging the country into a complete blackout.
Historical Context of Nuclear Incidents
Ukraine currently operates three nuclear power plants with a total capacity of 7.7 gigawatts. The fourth plant, Europe's largest, Zaporizhzhia NPP, is occupied by Russia and not operating.
The current generation deficit is about 10 gigawatts, which is only partially compensated for by imports, meaning authorities must implement large-scale rolling blackouts during which entire regions are left without power for hours.
One industry source, who asked not to be identified due to the sensitivity of the subject, said nuclear generation was now providing up to 80% of the power consumed in Ukraine, which has virtually no other generating capacity left intact.
With most of Ukraine's thermal power generation knocked out by Russian air strikes, the removal of the nuclear power stations would cause cities' infrastructure to collapse, the industry source said.
Zelenskiy previously said that domestic generation and imports cover only about 60% of demand.
Economy Minister Oleksiy Sobolev said at this week's World Economic Forum in Davos that Russian shelling since October 2025 has damaged 8.5 gigawatts of generating capacity in Ukraine, including thermal and hydroelectric power plants.
SUBSTATIONS AS KEY ELEMENT OF POWER SYSTEM
Nuclear power units are useless without powerful substations that can deliver the generated electricity to high-voltage grids and then, through smaller substations, to consumers.
Oleksandr Kharchenko, director of the influential independent Energy Research Centre in Kyiv, said that 10 key substations transported more than half the electricity consumed by Ukraine from nuclear power plants.
Some of the substations are located directly next to the nuclear power plants, while others are dozens or even hundreds of kilometres (miles) away.
HAVE SUBSTATIONS ALREADY BEEN ATTACKED?
Rafael Grossi, the head of the International Atomic Energy Agency, said this week that key Ukrainian power substations had already been "affected" by the latest Russian missile salvoes.
Kharchenko said that so far there had been no strikes on substations at nuclear power plants, but during the almost four years of war, Russia has attacked substations located far from power units at least 60 times.
The attacks target rare powerful transformers but protective measures have been put in place around them, and as a result of the strikes, only auxiliary equipment has been damaged.
Usually, such damage takes only a couple of days to repair and to return the substation to operation, Kharchenko said.
Still, the industry source said that nuclear power plants have been forced to reduce the output from nuclear reactors many times due to such attacks.
DANGERS OF ATTACKING SUBSTATIONS NEAR NUCLEAR PLANTS
Analysts and energy experts say the consequences of a missile strike on substations located near nuclear reactors are unpredictable as an explosion - even if it did not damage a reactor itself - could damage the system of piping that contains radioactive water, as well as other nuclear equipment.
Some substations are located just a few hundred metres (yards) from reactors, and hitting them could have unpredictable consequences.
An industry source noted that the reactor buildings were constructed of thick concrete and would not be easily penetrated by a drone's warhead, although a fire could damage other vulnerable objects of the power station. And they would not withstand a hit by a ballistic missile, the source said.
Ukraine already experienced a nuclear disaster when, in 1986, a power unit at the Chornobyl nuclear power plant exploded, rendering tens of thousands of hectares of land uninhabitable just 80 kilometres (50 miles) from Kyiv.
Kharchenko said that Russian missiles aimed at substations could simply hit the reactor or damage other key equipment - mainly kilometres of pipelines carrying radioactive water, turbine equipment or control systems at the nuclear power plant.
(Reporting by Pavel Polityuk; editing by Daniel Flynn and Mark Heinrich)
