Ukraine's Zaporizhzhia NPP shuts down last reactor in face of flooding threat

Ukraine’s military reported intense fighting with Russian forces on June 10, while the country’s nuclear energy agency said it put the last operating reactor at Europe’s largest nuclear power plant into a “cold shutdown” for safety as Russia’s war on Ukraine drags on through its 16th month.

Ukraine’s General Staff said Saturday that “heavy battles” were ongoing, with 34 clashes over the previous day in the country’s industrial east. It gave no details but said Russian forces were “defending themselves” and launching air and artillery strikes in Ukraine’s southern Kherson and Zaporizhzhia regions, AP News reports.

A day earlier, Russian President Vladimir Putin expressed his view that Ukrainian troops have started a long-expected counteroffensive and were suffering “significant” losses.

At the Zaporizhzhia Nuclear Power Plant, Europe’s largest, which is occupied by Russian forces, five out of six reactors were already in a state of cold shutdown, That’s a process in which all control rods are inserted into the reactor core to stop the nuclear fission reaction and generation of heat and pressure.

Energoatom, the Ukrainian nuclear agency, said in a statement late Friday that there was “no direct threat” to the Zaporizhzhia plant due to the breach of the Kakhovka dam further down the Dnieper River, which has forced thousands of people to flee flooding and also sharply reduced water levels in a reservoir used to help cool the facility.

Energoatom said it shut down the final reactor due to that, and also because of shelling near the site that has damaged overhead lines connecting the plant to Ukraine’s energy system.

With all nuclear reactions stopped, temperatures and pressure inside reactors gradually decline, reducing the required intensity of water cooling of the radioactive fuel. This is a nuclear power plant’s safest operating mode. Energoatom employees are still working at the power plant, although it remains controlled by the Russians.

The site’s power units have not been operating since September last year. The head of the International Atomic Energy Agency is due to visit Ukraine in the coming days.

Also on Saturday morning, Ukrainian authorities reported that at least four civilians have died across the country as Russian forces launched Iranian-made Shahed drones, missiles, and artillery and mortar strikes.

Ukraine’s State Emergency Service reported that three people were killed and more than two dozen wounded overnight in an attack targeting the Black Sea port of Odesa. A spokesperson for Ukraine’s southern operational command, Natalia Humeniuk, said two children and a pregnant woman were among those wounded.