Chernobyl 'Sarcophagus' That Holds in Radiation From the World's Worst Nuclear Disaster Is About to Cave in Under Its Own Weight

The vast structure that was built around the number 4 reactor at the Chernobyl Nuclear Power Plant, Ukraine, following the infamous 1986 disaster is on the verge of collapse, according to experts.

The "sarcophagus," or "Shelter Structure" as it is known, was constructed shortly after the worst nuclear disaster in history as a temporary measure to limit the radioactive contamination leaking out of the destroyed reactor.

But now the concrete and steel structure—which weighs around 8,000 tons—has degraded to such a point that there is a "very high" probability it will cave in on itself, according to officials from SSE Chernobyl NPP, the Ukrainian company that manages the plant, Brinkwire reported.

Fortunately, authorities have been planning for this eventuality. Last month, a new structure built around the sarcophagus was formally inaugurated.

Known as the New Safe Confinement or New Shelter, this 32,000-ton structure—which took around a decade to build at a cost of $2.3 billion—should keep the radiation contained for about another century.

This gives workers plenty of time to disassemble the older structure and decontaminate the materials from it. Chernobyl NPP has just awarded a contractor this task and set a completion date of 2023, the year that experts have suggested the sarcophagus would be able to survive until in the best-case scenario.

"This is the next logical step resulting from our work carried out over the latest 12 years," Serhii Kalashnyk, acting director-general for the firm, said in a statement.

"The contractor has simultaneously to disassemble Shelter and to reinforce it as the removal of every element will increase the risk of Shelter collapse, that in turn will cause the release of large amounts of radioactive material," he said.

All of the disassembled elements from the sarcophagus will be cut up, decontaminated and then put into shipping containers for transportation to a processing or disposal facility.

The disassembly contract will be funded by the Ukrainian state budget, unlike the construction of the New Safe confinement which was financed by the Chernobyl Shelter Fund (CSF)—an organization founded in 1997 that counts 28 member states as contributors.

The CSF was set up to fund the Shelter Implementation Plan—a scheme intended to make the Shelter an environmentally safe system for 100 years.

The Chernobyl disaster took place on April 26, 1986, when a failed safety test of the number 4 reactor at the power plant caused a huge explosion, releasing huge amounts of radiation into the environment. A mixture of human error and a critical design flaw have been blamed for the accident.

Construction of the New Shelter was completed in 2018, while its final commissioning tests were wrapped up in April this year.

Chernobyl, New Safe Confinement
A picture shows a monument near the New Safe Confinement (NSC) new metal dome designed and built by French consortium Novarka encasing the destroyed reactor at Chernobyl plant on July 10, 2019, in Chernobyl. SERGEI SUPINSKY/AFP/Getty Images