IAEA inspectors who visited the site in early September and have remained there say safety backup systems are working. 

In remarks before the agency governing board on Sept. 12, Director General Rafael Mariano Grossi called the situation  “untenable” and warned of potentially catastrophic outcomes if the plant's physical integrity continued to be compromised. “The protection zone is essential to end the repeated shelling of the plant and of the off-site power infrastructure crucial for reactor cooling and other systems needed to maintain safety now that all reactors at [the plant] are in shutdown.”

Grossi said he is in discussions with relevant authorities to establishing a safety zone. 

The situation remains extremely volatile by all accounts. On Sept. 5, the plant, which is still being operated by Ukrainian staff, lost its connection to the Ukrainian power grid. The last operating reactor was used to power the plant and keep its spent fuel pools cool.

When power was restored on Sept. 11 through a 330-kV reserve line—which connects the plant to the Ukrainian network through the switchyard of a thermal power station in the nearby city of Enerhodar—operators were able to shut down the ZNPP's last nuclear reactor. 

Edwin Lyman, director of nuclear safety at the Union of Concerned Scientists, said one of the biggest risks is a potential long-term power interruption.

If power to the ZNPP is interrupted, diesel generators would be able to temporarily provide the power needed to cool the reactors and spent fuel, but resupply could be an issue. “Fuel stays hot for a very long time. It does cool down rapidly, but you still need to supply that cooling water steadily for many weeks or months afterwards.” 

The ZNPP has 20 onsite diesel generators with enough fuel for 10 days, according to the IAEA. Grossi has said that the plant has not yet had to rely on the generators. 

Steve Arndt, president of the American Nuclear Society and a former senior technical advisor for the U.S. Nuclear Regulatory Commission, says that the problem should not be the functionality of the generators, if they need to be used.

But it could be a problem if the ongoing war impacts resupply of fuel for the generators.

“The good thing from an operational and safety standpoint is that the other five [reactors] have been shut down right now for some time. As the amount of time since shutdown gets longer than the loads … you simply don’t need as much cooling,” says Arndt. 

Related Infrastructure Work Down

Related to other infrastructure related construction in Ukraine, a spokesman for Turkish contractor Onur Group, which had a presence in-country since 2004, said its regular project work remains suspended.

"We only carry out urgent emergency projects and continue to build projects with international financing, such as the construction of a new bridge in the city of Irpin, near Kyiv," he told ENR.  "The Russian army destroyed this bridge in the first weeks of the war.  We also continue to carry out construction on roads in the western regions of Ukraine on a small scale. This part of the country is now the safest in wartime."

He says company top management, mostly Turkish citizens, "stayed to work during the war and did not leave the country,"  with about 2,000 total company employees working in the firm's non-contracting businesses.

The spokesman notes that despite heavy shelling of the Zaporizhzhia nuclear power plant, the firm's newly opened 166-m-high cable-stayed bridge in the city of Zaporizhzhia, has not been hit.

Onur Group was contractor for the estimated $420-million structure, which was built to connect what had been a city of 750,000 residents and is the tallest bridge in Ukraine.