He Chernobyl accident released so much radiation that some areas they remain uninhabitable almost four decades later. In fact, the plant continues to house materials capable of remaining dangerous for thousands of years. Therefore, keeping them under control is one of the greatest engineering challenges ever faced in Europe.
A challenge that a drone has put to the test.
It was to last a century. The story we tell it a few months ago. The gigantic steel arch built over Chernobyl reactor 4 was conceived as a definitive solution to contain the worst nuclear accident in history for at least a hundred years, a colossal structure designed to isolate the ancient “sarcophagus” and buy humanity time.
More than 100 meters high and capable of housing entire monuments inside, this system had to resist extreme conditions and allow the safe decommissioning of the reactor, encapsulating hundreds of tons of radioactive material that remain active decades after the disaster.
The impact that changed everything. But everything changed in February 2025when a drone attack in the middle of the night pierced that shell seemingly invulnerable, opening a breach in the structure and exposing a system that was never designed to operate in a war environment.
Although there were no immediate leaks or casualties, the damage compromised critical functionsespecially ventilation that controls humidity and prevents corrosion, introducing a silent but growing risk that could degrade the structure in a few years.
What is still hidden under the steel. Under the damaged arch remains an environment extremely unstable: remains of the reactor, tons of nuclear fuel and melts of highly radioactive materials that continue to react slowly.
The old “sarcophagus,” hastily built in 1986, was never structurally reliableand is actually completely dependent on the new cover to maintain the insulation. In other words, if that balance fails, the risk is not immediate, but potentially devastating, with the possibility of release radioactive dust that the wind could disperse throughout Europe.
A “reform” as expensive as it is complex. System restore will not be neither quick nor easysince it involves working in conditions of high radiation, with strict limitations on time and exposure for operators.
Temporary solutions barely contain the most urgent damage, while full restoration will require rebuilding highly specialized internal layers within a structure designed as a technical “sandwich”. We are talking about an estimated cost that exceeds 500 million of euros, a figure that reflects both the technical complexity and the hostile environment in which repairs must be carried out.
The war enters Europe’s greatest nuclear risk. If you like, the incident it is not isolatedbut part of a context in which nuclear infrastructure have become exposed elements within an active conflict.
Paradoxically, the Chernobyl exclusion zone that we had to protect from any danger has been the scene of military operationstroop movements and constant overflights of missiles and drones, which multiplies the risk of new impacts, whether accidental or intentional. In that scenario, even a technical failure or trajectory error could trigger consequences continental in scope.
A reminder of what never ended. They remembered in a special from the Financial Times this week that, decades after the accident, Chernobyl remains the same latent threat, one that requires constant vigilance and international cooperation, and the drone impact has revealed the fragility of the systems designed to contain it.
The infrastructure that was to definitively close the disastrous episode of 1986 now faces a new type of risk, thus demonstrating that nuclear safety depends not only on engineering, but also of geopolitical stabilitya (and common sense).
In that delicate balance, each crack is not just a structural failure, but a warning about the limits of our ability to control the consequences of our own creations.
Image | EBRD
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