The protective shelter built to contain radioactive material from the 1986 Chernobyl disaster can no longer block radiation after an attack by Russia.
A suspected Russian drone hit the power plant in northern Ukraine earlier this year, starting a fire in the outer cladding of the massive steel structure.
At the time, the strike sparked fears of a radioactive leak, which could cause a disaster in Ukraine and wider Europe.
The UN’s nuclear watchdog, the International Atomic Energy Agency (IAEA), has now confirmed that the structure of the shelter has degraded.
According to the IAEA, the steel shelter has lost its ‘primary safety functions’, including the ability to confine radioactive material.
But no permanent damage occured to its load-bearing structures or monitoring systems.
Rafael Grossi, director general of the IAEA, said: ‘Limited temporary repairs have been carried out on the roof.
‘But timely and comprehensive restoration remains essential to prevent further degradation and ensure long-term nuclear safety.’
The nuclear watchdog said further restoration and protective work of the structure is needed.
This includes ‘humidity control measures and an updated corrosion monitoring programme – as well as an upgrade of an integrated automatic monitoring system for the shelter object structure built on top of the reactor immediately after the accident’.
Temporary repairs to the site will be made in 2026 to ensure radioactive material is confined, the IAEA said, adding that there are plans to complete a ‘full restoration’ once the war between Russia and Ukraine ends.
Grossi said: ‘The IAEA – which has a team permanently at the site – will continue to do everything it can to support efforts to fully restore nuclear safety and security at the Chornobyl site.’
On Monday the agency began a 12-day visit to Ukraine to assess the status of electrical substations critical for nuclear safety and security, following recent military attacks targeting energy infrastructure.
More than 10 substations, which are essential to the electrical grid related to the nuclear power plants, will be assessed to review damage and repair efforts, according to the IAEA.
Grossi said: ‘These substations are essential for nuclear safety and security.
‘They are absolutely indispensable for providing the electricity all nuclear power plants need for reactor cooling and other safety systems.
‘They are also needed to distribute the electricity that they produce to households and industry.’
Previous IAEA inspections have highlighted a ‘continued degradation of the grid and increased challenges to the transmission infrastructure’.
Get in touch with our news team by emailing us at webnews@metro.co.uk.
For more stories like this, check our news page.