KYIV, Ukraine – Shelling once again threatened the safe operation of the Zaporizhzhia nuclear power plant, even as United Nations officials expressed cautious optimism that a permanent presence of its inspectors at the plant was helping to lower the risk of a nuclear disaster.
The plant lost the connection with its last remaining main external power line after shelling on Friday evening, forcing engineers to rely on a lower-voltage reserve line to power the cooling equipment needed to prevent meltdowns, the International Atomic Energy Agency (IAEA) said in a statement.
Nuclear power plants must sometimes rely on external power drawn from the grid to cool the reactor cores and spent fuel. If the external power lines are cut, the Zaporizhzhia plant must turn to backup diesel generators, and if those malfunction or run out of fuel, a meltdown becomes possible.
After visiting the plant, Rafael Mariano Grossi, director of the agency, told a news conference on Friday that his biggest concern regarding the physical safety of the facility itself was related to a reliable connection to external power.
That connection has been severed at least twice in recent weeks. When the main power lines and the reserve line were damaged by shelling and fires on Aug 25, there was a blackout at the plant, and diesel generators had to be relied on to prevent a disaster.
The IAEA said it was informed by Ukraine that it had happened again on Friday night after renewed shelling in the area.
Fighting has raged across southern and eastern Ukraine, and the plant lies precariously close to the front lines of some of the most intense fighting.
Grossi, who has avoided placing blame for the shelling on either the Russians or Ukrainians, said on Friday that it appeared the power supply to the plant was being deliberately targeted.
“It is clear that those who have these military aims, know very well that the way to cripple or to do more damage is not to look into the reactors which are enormously sturdy and robust,” he said.
Instead, it is being hit where it hurts – the critical power lines essential for running the plant.
Without external power, the cooling system of the plant can cease functioning, nuclear experts say. Power is needed to pump water past the nuclear core and carry heat away. Although the chain reaction in the core can be shut off quickly, the radioactive material there will continue to give off heat for a long time and can eventually damage the radioactive fuel or the reactor.
On Saturday, Grossi said the presence of the agency’s inspectors, who were able to confirm the damage to the external power line, was already proving valuable. He called it a “game-changer.”
“Our team on the ground received direct, fast and reliable information about the latest significant development affecting the plant’s external power situation, as well as the operational status of the reactors,” he said.
One of the six reactors at the plant is currently operational, the agency said, and is producing electricity both for cooling and other essential safety functions at the site and for Ukrainian households and factories.
Najmedin Meshkati, a professor of civil and environmental engineering at the University of Southern California, said the presence of monitors at the Zaporizhzhia plant was a good thing, but he warned that only time would tell if it changes the behavior of the Russian forces in control of the facility.
Beyond the radiation risks should there be an accident, it is a vital piece of infrastructure that can power 4 million Ukrainian homes and could continue to be used as leverage by Moscow. Russian forces could wait for international focus to shift and then – when Ukrainians need the power the most this winter – “pull the plug on this plant.” THE NEW YORK TIMES
