The International Atomic Energy Agency has reported that Ukraine’s operating nuclear power plants reduced electricity production yesterday morning as a precautionary measure following widespread military activities across the country that reportedly targeted its energy infrastructure.

The European Union has selected a Westinghouse-led consortium to develop and deliver “a secure, fully European nuclear fuel supply” for Russian-designed VVER reactors in the EU and Ukraine, the U.S.-based firm announced last week.

In what it is calling a “major expansion” of its efforts to prevent a severe nuclear accident befalling Ukraine, the International Atomic Energy Agency yesterday announced that it is deploying teams of nuclear security and safety experts this week to the beleaguered nation’s nuclear power plants and the Chernobyl site. (The agency has already stationed a team of experts at Ukraine’s largest nuclear facility, the six-unit Zaporizhzhia plant, which has been under Russian military occupation since last March.)

The war in Ukraine notwithstanding, Westinghouse Electric Company has stepped up its partnership with Energoatom, Ukraine’s state-owned nuclear utility, signing agreements last week to supply all of the nuclear fuel for the country’s operating reactor fleet and to collaborate on the construction of nine AP1000 units for Ukraine, rather than the five earlier envisioned.

The director general of the International Atomic Energy Agency, Rafael Mariano Grossi, led a mission to Ukraine’s Chernobyl nuclear plant this week to address ongoing radiological safety concerns at the shuttered site following five weeks (February 24–March 31) of Russian military occupation.

Ukraine’s nuclear operator, Energoatom, announced yesterday that the Russian military has withdrawn from the Chernobyl plant and surrounding area. “According to the staff of the Chernobyl nuclear power plant, there are now no outsiders on-site,” Energoatom stated in an online post. Russian forces took control of Chernobyl on February 24, day one of the invasion.

In a separate post, the company said that the Russians had formally agreed to return the responsibility for Chernobyl to Ukraine. It shared a scan of a document, with the heading “Act of acceptance and transfer of protection of the Chernobyl nuclear plant,” purportedly signed by a representative of Russia’s National Guard, a representative of Rosatom, Russia’s state atomic energy corporation, and a Chernobyl plant shift manager.

International Atomic Energy Agency director general Rafael Mariano Grossi said on Wednesday that he remains “gravely concerned” about Ukraine’s nuclear sites amid the ongoing Russian invasion and stressed the urgency of reaching an agreement on a framework that would enable his agency to provide technical assistance to ensure the safe and secure operation of those facilities.

The events of the past 12 days are unprecedented and nerve-wracking for the nuclear community. Never before has a nuclear power plant been in a full-scale war zone until the Russian invasion of Ukraine started on February 24. The world watched nervously as Russian troops and heavy equipment rolled through the Chernobyl site and then a week later attacked the Zaporizhzhia nuclear power plant. Russian forces are now less than 50 kilometers from the South Ukraine nuclear power plant.

Denying a Russian claim of control of the Zaporizhzhia nuclear power plant, Energoatom earlier today declared that “Russian propaganda media reports that the invaders allegedly took control of the Zaporizhzhia NPP are a cynical fake.” According to Energoatom, all four of its nuclear power plants are under the control of Ukraine and are operating normally with enhanced defenses.

Russian forces invaded Ukraine today in what news sources are calling the largest military attack of one state against another on the European continent since World War II. These developing events follow an extraordinary meeting of the NATO-Ukraine Commission in Brussels on February 22, when NATO secretary general Jens Stoltenberg said that Russia’s recent actions constituted “serious escalation” of tensions in the region and that Russia had shifted from covert attempts to destabilize Ukraine to overt military action. Well before this juncture was reached, news outlets had questioned the readiness of Ukraine’s nuclear power fleet to operate safely in a country at war and ensure energy security, while Energoatom, which operates all of Ukraine’s nuclear power reactors, has issued assurances of safety and security.