International concern about Russia capturing nuclear power plant sites, including the defunct Chernobyl — site of the world's worst nuclear disaster in 1986 — has been mounting since the Russian-Ukrainian war began last month.
Chernobyl, which is around 100 kilometres north of Kyiv near the Belarus border, was seized by Russian forces on the first day of the invasion.
Yesterday, the United Nations' nuclear watchdog said it had lost all communications with the Chernobyl site, along with Zaporizhzhia — the largest nuclear power plant in Europe.
It comes after power to the Chernobyl plant was cut earlier in the week.
These developments have prompted meetings between the International Atomic Energy Agency (IAEA) and Ukrainian and Russian authorities.
Here's what we know.
What's the current situation?
Since a botched safety test in the fourth reactor of the plant in 1986, the remaining activities around the plant have focused on safety — namely nuclear waste management and storage.
It also became a tourist attraction decades later, but was shut down for tourists about a week before the Russian invasion of Ukraine began.
Yesterday Ukraine informed the IAEA that it had lost all communications with the Chernobyl plant — a day after the site lost all external power supplies.
There have been reports from Russia that power has been restored to the site, but the IAEA is yet to confirm those.
The loss of power to the site was of particular concern to Ukraine's Deputy Prime Minister Iryna Vereschuk, who feared the loss of power could lead to radiation leaks.
But the IAEA said the loss of power did not represent a critical impact to safety because the site had emergency power supplies in the way of diesel generators and batteries.
IAEA Director General Rafael Grossi however did say that the lack of power would likely lead to "a further deterioration of operational radiation safety" and create additional stress for the 210 technical experts and guards who have been living at the site since it was taken under Russian control.
The Ukrainian regulator said the staff had access to food and water, and a limited amount of medicine, while the IAEA said they were facing "psychological pressure and moral exhaustion".
How worried should we be?
Although Chernobyl no longer generates nuclear power, it constantly feeds information to the regulator to ensure the site's radiation is monitored, there is adequate ventilation, and the site is generally safe.
Before communications were lost from the site the information received by the Ukrainian regulator showed both of the power lines to the site had been damaged and had been disconnected from the grid.
Again, the IAEA said the site's disconnection from the electricity grid would not have a critical impact on the site, particularly where several radioactive waste management facilities are, because there is enough water to keep the site cool even without a supply of electricity.
But the loss of communication means the Ukrainian regulator cannot provide updated information about the site to the IAEA — however the regulator has been able to confirm that there has been no damage to the structure and systems at the site.
The IAEA is also concerned about the impact the lack of communication is having for staff who are at the site.
The Director General said operational staff have been faced with "deteriorating and exhausting conditions" and have been unable to rotate since February 24.
Mr Grossi said this was compromising a vital safety pillar which states that "operating staff must be able to fulfil their safety and security duties and have the capacity to make decisions free of undue pressure".
The site had previously been able to communicate with the regulator by email, which has since ceased.
Where to from here?
The IAEA is preparing to present ideas to both the Russian and Ukrainian authorities on how to ensure the safety of nuclear facilities in Ukraine as Russia's invasion continues.
Yesterday Mr Grossi met separately with both Russia and Ukraine's foreign ministers after their meeting in Turkey.
Speaking after the meetings, he said he was optimistic the two countries could come to a resolution about managing the nuclear sites.
“I am quite encouraged on one important thing — Ukraine and the Russian Federation want to work with us and agreed to work with us,” Grossi said.
“We have to move fast.”
