Chernobyl’s decrepit “sarcophagus” is on the brink of collapse. 

In the months following the Chernobyl Nuclear Power Plant in 1986, Soviet authorities built a temporary shelter over the reactor number 4 building in the desperate hopes of confining its tons upon tons of radioactive corium, uranium, plutonium, and highly contaminated dust. 

Now, it’s feared the crumbling inner structure is finally on its last legs and has a “very high” possibility of collapse. While the old sarcophagus is encased inside another modern steel structure, known as the Chernobyl New Safe Confinement, the possibility of collapse would make the process of dismantling the plant even more complicated.

"The structures of [the] shelter, built more than 30 years ago, are simply supported and are kept on the supporting blocks only due to the force of gravity," the company that manages the Chernobyl plant site said in a statement.

"The removal of every element will increase the risk of shelter collapse that in turn will cause the release of large amounts of radioactive materials inside the inner space of New Safe Confinement arch."

Measuring 275 meters (900 feet) wide and 108 meters (354 feet) tall, the new 36,000-tonne super-structure (image above) was slid into place in November 2016, providing protection for the final phases of decommissioning, which kicked off in July 2019. Much of this work is done using remotely operated cranes that are able to dismantle the ruins for processing, decontamination, or disposal. In doing this, workers have discovered that the old "sarcophagus" could collapse with any move, running the risk of spraying radioactive contamination around the containment structure. Fortunately, this new structure means the wider risk to public health is low.

The meltdown and explosion at Chernobyl was the worst nuclear disaster in history, spewing a cloud of radioactive material that drifted into other parts of the then-USSR. The World Health Organization estimates that the total radioactivity from Chernobyl was 200 times that of the combined releases from the atomic bombs dropped on Hiroshima and Nagasaki, according to The Lancet.

The disaster is estimated to have cost some $235 billion in damages, with the New Safe Confinement alone coming with a price tag of over $2.3 billion. However, the total economic cost is hard to gauge. 

The number of people killed as a result of the disaster remains disputed. Although a report by the UN-backed Chernobyl Forum in 2005 argued that fewer than 50 people had died as a result of exposure to radiation, that figure has been heavily contested. One study, published in the International Journal of Cancer in 2006 estimates a total of 16,000 deaths across Europe.