Russian drone strikes near a nuclear power plant in western Ukraine this week have revived anxiety among Ukrainian officials and civilians over one of the most oppressive hardships of the war: a winter assault on their nation’s energy grid.
The strikes on Wednesday, which landed near the Khmelnytsky nuclear facility, drew an angry response from President Volodymyr Zelensky of Ukraine, who said it was “highly likely” that the power plant was the target. They also prompted another warning from the head of the United Nations nuclear watchdog agency about the precarious nuclear safety situation in Ukraine.
Mr. Zelensky vowed on Wednesday night that Ukraine would hit back at targets inside Russia if Moscow tried once again to plunge his nation into cold and darkness.
“This year we will not only defend ourselves but also respond,” he said.
Unlike a year ago, Kyiv now has a growing fleet of long-range drones and has demonstrated an ability to hit military targets deep inside Russia.
Still, Ukraine remains vastly outgunned when it comes to long-range strike capabilities, and Ukrainian and Western officials have warned that it is likely that the Kremlin is stockpiling missiles to renew its assault on the energy grid as winter begins to bite.
The first Russian strikes specifically aimed at Ukrainian energy infrastructure in six months were reported on Sept. 21, when the Ukrainian air force said it shot down 36 of 43 cruise missiles aimed at targets around the country. The attacks led to partial blackouts in the Rivne, Zhytomyr, Kyiv, Dnipropetrovsk and Kharkiv regions, Ukraine’s state energy operator, Ukrenergo, said in a statement.
Since then, there have been few reported strikes involving Russian missiles — a period of quiet that is in itself unnerving.
“This may indicate a preparatory period for the enemy,” Natalia Humeniuk, a spokeswoman for the Ukrainian southern command said.
A year ago, Russia destroyed roughly 61 percent of Ukraine’s electricity generation capacity, while also targeting its water supply and internet access. Many civilians resorted to candles to light homes and bathed using buckets. The absence of cellphone power and elevators in apartments that stopped working proved an additional challenge.
The attacks brought months of hardship for millions of Ukrainians. One couple, Andriy Veles and Tetiana Zubko, both 28, relied on the support and kindness of friends and neighbors last winter as they raised twin baby girls.
“The problem is not the blackouts,” Mr. Vales said. “The problem is no water, no heating, no cellular.” The couple, who live on the fifth floor of an apartment block in the capital, Kyiv, said the elevator broke, running water stopped and they resorted to using candles, a gas stove, a large power bank and cans to store water. This winter they would be better prepared, Ms. Zubko said.
Ukrainian energy providers also say they are better prepared to withstand a Russian onslaught this time. In particular, they said that many damaged facilities had been repaired, new equipment had been readied to provide spare capacity in case of attack and defenses had been built around electricity substations and other pieces of critical infrastructure.
“We have learned our lessons from last winter,” said Maxim Timchenko, the chief executive of DTEK, Ukraine’s largest private energy company.
The Kyiv School of Economics estimated in early September that the cost of direct damage to Ukraine’s energy infrastructure was more than $8.8 billion so far.
The campaign failed in large part because of the heroic work of utility workers to make urgent repairs even while under threat, as well as Ukraine’s ability to draw power from neighboring countries in Europe and the outpouring of support from the country’s allies.
Volodymyr Kudrytskyi, the head of Ukrenergo, said that the winter war was in many ways a battle between engineers.
“The Russians are trying to figure out how to inflict as much damage as possible, what elements of the grid should be taken down,” he said in an interview earlier this month. “We are trying to figure out how to bring back lights to businesses and households as quickly as possible.”
Last winter, the Russian attacks were aimed at weakening the nation’s resolve and undermining the nation’s capacity to support its war effort. They also threatened to render cities that are home to millions of people uninhabitable, prompting another wave of refugees flooding into Europe.
The darkest hours came in November, after a Russian missile barrage knocked all the country’s nuclear power plants offline at the same time.
The ferocity of the Russian strikes — which often featured waves of more than 100 missiles and drones in a single attack — prompted Ukraine’s allies to speed up delivery of the air defense systems that the government in Kyiv had wanted since the first days of the war.
Petro Kotin, the head of Ukraine’s nuclear energy utility, Energoatom, said that the defenses around the country’s nuclear facilities were constantly being improved.
“This is a task for our military and their special anti-drone equipment,” he told journalists during a tour of the Khmelnytsky plant in September.
It is one of three working nuclear power plants under the government’s control, which together provide roughly half of the nation’s power.
Rafael Mariano Grossi, the head of the U.N.’s International Atomic Energy Agency, said that it had experts at the Khmelnytsky plant when air raid alarms sounded at 1:26 a.m. Wednesday, followed by two loud explosions.
One drone was shot down about three miles from the plant and another about 12 miles away, the agency reported.
They were part of a swarm of 11 drones that targeted the area, Ukrainian officials said. While they were all shot down, at least 20 people were injured and scores of homes and business were damaged by falling debris, Ukrainian officials said.
Yuriy Ihnat, a spokesman for Ukraine’s air force, said it was impossible to say for sure if the nuclear power plant was the main target of the attack since the drones were shot down. However, he said, Russia targeted the power lines linking nuclear power plants to the grid last year and it was likely they would employ a similar strategy this year.
“It is clear that Russia may focus attacks exactly where it did last year, so every assistance package, every system that is provided to Ukraine, even if it is an older one” is essential, Mr. Ihnat said.
There was no direct impact from this week’s drone attack at the plant and the blasts did not affect its operations or its connection to the national electricity grid, the U.N. agency reported.
The shock waves damaged the windows of several buildings at the site, including the passageway to the reactor buildings and the training center, the agency reported. Two of the plant’s 11 off-site radiation monitoring stations were briefly knocked offline.
“The fact that numerous windows at the site were destroyed shows just how close it was,” Mr. Grossi said. “Next time, we may not be so fortunate.”
Yurii Shyvala contributed reporting