Russia’s military occupation of Ukraine’s partially destroyed Chernobyl nuclear power plant is putting "in jeopardy" international efforts to make the site safe, says the agency that managed funding of the $2.8-billion program to shield its damaged reactor.

The March 11 warning by the European Bank for Reconstruction and Development followed s March 10 announcement by the International Atomic Energy Agency that Ukrainian authorities had lost communications with the plant one day after all external power supplies to the site were severed. The agency raised a similar warning related to communications with Ukraine's still functioning Zaporizhizhia power plant, its largest, which Russian troops have occupied since earlier this month, said a March 10 Reuters report.

IAEA is "concerned about the sudden interruption of such data flows to the [the global agency's] Vienna headquarters from the two sites, where large amounts of nuclear material are present in the form of spent or fresh nuclear fuel and other types of nuclear material," it said in a March 10 statement.

The warnings come as damage costs to Ukraine's infrastructure, buildings and other physical assets from Russian attacks now is estimated to be $100 billion, its top government economic adviser Oleg Ustenko said during an online event on March 10 sponsored by the Peterson Institute for International Economics.

He said some funding for reconstruction could come from Russia's financial assets that are frozen globally by Western nation sanctions, including those of wealthy Russian oligarchs.

Power Failure

Ukrainian power regulators had notified the international nuclear power agency that both of the Chernobyl site’s power lines had been damaged. Agency officials are seeking confirmation of reports that power had been restored, according to director general Rafael Mariano Grossi.

To maintain safety of the highly radioactive reactor's remains following the massive explosion there in 1986, the bank highlights the need to maintain monitoring and control systems as well as uninterrupted power, and calls for resumption of normal shift rotations and supplies to the “depleted” workforce.

“Any military action on site is extremely dangerous for the old spent fuel storage facility,” the bank adds.

The fourth reactor at the inactive plant was covered in late 2016 by a 108-m-tall, 162-m-long steelwork vault that spans 257 m. It was built by the Novarka joint venture of Paris-based VINCI Construction Grands Projets and Bouygues Travaux Publics, under a turnkey contract signed in 2007.

Until completion of the vault, the highly radioactive reactor's remains were contained by a “sarcophagus” made with 400,000 tons of concrete and 7,000 tons of steelwork.

Soviet engineers began designing the sarcophagus within three weeks of the accident and a heroic labor force completed the structure that November. At least 50 of the workers later died from radiation illnesses, according to a study by U.N. agencies.