Dismantling Chornobyl NPP reactor jeopardized by Russian drone strike

The arch-shaped sheath accounted for many safety issues — from earthquakes and tornadoes to strong winds and record snowfall — but it was not designed to endure combat operations.

A Russian kamikaze drone struck the structure on Feb. 14, jeopardizing plans to dismantle the reactor and safely dispose of radioactive waste over the next five years. 

The arch — installed over the plant’s fourth reactor in 2016 — is the world’s largest movable structure. More than 45 countries and international organizations invested about $1.7 billion in its construction. A Russian drone worth $20,000 pierced a hole in the arch’s steel cladding, sparking a fire.

“We conducted many safety analyses, considering various threats,” the article quotes Eric Schmieman, a U.S. engineer who served as a senior technical adviser on the project.

“We factored in earthquakes, tornadoes, strong winds, even century snowfall — but we did not plan for combat operations.”

Although Ukrainian firefighters quickly extinguished the initial blaze, a watertight membrane inside the arch’s insulation began to smolder — a process that lasted nearly three weeks. Firefighters, equipped with climbing gear, had to drill holes in the outer shield to locate the hotspots and spray water inside the structure. The structure was meant to remain dry to prevent corrosion.

Ukrainian officials said about half of the northern shield section was damaged. Radiation levels outside the plant remain within normal limits, but it is unclear how the damaged arch will ultimately be restored.

Experts believe repairs could take years, complicating plans to dismantle the destroyed reactor. There is also a risk that the steel shell will begin to rust or that the temporary “sarcophagus” — built by Soviet engineers nearly 40 years ago and still inside the shelter — will continue to deteriorate.

“The outer shell is key for protecting against precipitation, while the inner shell is designed to contain radioactive dust,” Schmieman said. That design is critical now as cranes inside have begun dismantling the sarcophagus and the damaged reactor ahead of safe waste disposal.

Officials had planned to complete the first phase of dismantling by year’s end. 

“Unfortunately, that is no longer possible,” said Artem Siryi, chief of facility operations. 

Experts are now assessing whether the shelter can be restored at all. Workers face the task of closing a 50-square-meter opening and sealing small holes drilled during firefighting. In addition, the damaged membrane and internal structures must be repaired, and moisture levels—elevated during firefighting—must be reduced.

Experts warn that these repairs may prove impossible because workers would have to operate in an environment with high radiation levels. Moving the structure for repairs also poses major challenges.

“Full restoration of the facility is virtually impossible,” Siryi said.

“Getting it close to its original state would likely cost hundreds of millions of dollars.”