Worker at Zaporizhzhia nuclear power plant warns of potential catastrophe

As Russia and Ukraine trade accusations over attacks on Europe's largest nuclear power plant, a worker there told ABC News he fears not only for the safety of his family but also the world.

"If something happens to the spent fuel storage, the consequences could be the same as Chernobyl," the worker, who spoke to ABC News on condition of anonymity, warned during an interview in the southeastern Ukrainian city of Zaporizhzhia on Tuesday.

The Ukrainian man, who is an engineer at the Zaporizhzhia nuclear power plant near the town of Enerhodar, said he plans to return to work soon out of a sense of duty to his country, despite his wife urging him to quit. He described how the Russian soldiers at the plant "are always armed and wear balaclavas."

"If they don't like the look of you, they can yell at you," he said. "I've heard that some people were beaten."

Shortly after invading neighboring Ukraine on Feb. 24, Russian troops stormed the Zaporizhzhia plant, on the banks of the Dnipro River in the country's southeast. The Ukrainian workers have been left in place to keep the plant operating, as it supplies electricity across the war-torn nation.

"If everyone leaves the station, who will work there? We need to help Ukraine," the engineer told ABC News.

However, heavy fighting around the site has fueled fears of a catastrophe, like what happened at the Chernobyl nuclear power plant in northern Ukraine over 36 years ago.

On April 26, 1986, a reactor at the Chernobyl plant, about 65 miles north of Kyiv, exploded and spewed enormous amounts of radioactive material into the atmosphere, forcing more than 100,000 people within a 1,000-square-mile radius to evacuate. It remains the world's worst nuclear accident.

Russian forces seized the now-defunct Chernobyl plant and the vast, surrounding radioactive area soon after launching the invasion but ceded control of the facility to Ukrainian troops when they withdrew from the area at the end of March.

Meanwhile, skirmishes between Russian and Ukrainian forces near the Zaporizhzhia plant caused a fire to break out at a training complex there in early March. On Aug. 5, shelling at the site resulted in several explosions near the electrical switchboard, causing a power shutdown, according to the International Atomic Energy Agency (IAEA), the nuclear watchdog of the United Nations.

Last week, IAEA Director-General Rafael Mariano Grossi warned that the situation at the Zaporizhzhia plant has deteriorated rapidly to the point of becoming "very alarming" and the agency's technical experts must be allowed to visit the area to address mounting safety concerns.

On Wednesday, in his nightly address, Ukrainian President Volodymyr Zelenskyy said Russian troops must "immediately" withdraw from the Zaporizhzhia plant and nearby areas "without any conditions."

"Any radiation incident at the Zaporizhzhia NPP can affect the countries of the European Union, Turkey, Georgia and countries from more distant regions. Everything depends solely on the direction and speed of the wind," Zelenskyy warned. "If Russia's actions cause a catastrophe, the consequences may also hit those who remain silent so far."

The Ukrainian president also accused Russia of using "the cover of the plant" to launch strikes on nearby Ukrainian-controlled territories and storing troops, weapons and equipment in its facilities. Russia has denied the allegations and accused Ukrainian forces of repeatedly firing on the site.

If shelling hits the spent fuel storage at the Zaporizhzhia plant, the engineer told ABC News "it might be like another Chernobyl," as radioactive material will leak and contaminate the environment.

"Every day, the Russians come closer and closer to the unit, shellings are closer and closer," he said. "There is no order or stability."

ABC News' Morgan Winsor contributed to this report.