Atomic Energy Agency Director Rafael Grossi said on Tuesday that systems that allow remote monitoring of nuclear material at the Chernobyl nuclear plant near Kyiv, which is currently under Russian control, have stopped sending data to the agency.
Grossi added in a statement that the remote transmission of data from the safeguards monitoring systems installed at the Chernobyl nuclear power plant was interrupted.
Safeguards is a term used by the International Atomic Energy Agency to describe the technical measures it applies to nuclear materials and activities, with the aim of deterring the spread of nuclear weapons through early detection of any misuse of these materials.
More than 200 Ukrainian technicians and guards are still stuck at the site and have been working for 13 consecutive days under Russian surveillance.
The International Atomic Energy Agency asked Russia to allow these employees to work in rotation, to rest and to work for a specified number of hours, considering these conditions necessary to ensure the safety of the site.
Grossi warned of the difficult and stressful situation in which Chernobyl nuclear power plant workers find themselves and the potential risks this poses to nuclear security.
With the transmission of remote data interrupted and the Ukrainian authority only able to contact the nuclear facility by e-mail, Grossi reiterated his offer to pay a visit to the site or elsewhere to obtain from all parties a "commitment on safety and security" at Ukraine's nuclear power plants .
On the first day of its invasion of Ukraine on February 24, Russia took control of Chernobyl, which in 1986 witnessed the worst nuclear accident in human history.
Last Friday, the Russian military announced that it had taken control of the Zaporozhye nuclear power plant in southeastern Ukraine.
Kyiv accused the Russian forces of bombing the station with artillery, which caused a fire in it, while Moscow denies any connection with the fire.
Zaporizhia is the largest nuclear power plant in Europe. Its reactors entered service between 1984 and 1995. It is of a modern design compared to Chernobyl, which was built in 1970 and was the first nuclear power plant in Ukraine.