What would happen if Zaporizhzhia nuclear power plant were to explode?
Russia’s attack on the Zaporizhzhia nuclear power plant has raised the specter of the reactors potentially being damaged leading to meltdown.
Russian president Vladimir Putin has told his military chiefs to put the nation’s strategic deterrence on high alert, including its nuclear arsenal. However, there is a potentially even greater risk of a nuclear catastrophe on the ground in Ukraine as that country's nuclear power plants are seized by the invading forces.
Ukraine has 15 active nuclear reactors spread across the country and four decommissioned at Chernobyl. Russian troops captured the Chernobyl nuclear facility at the beginning of the invasion and have now taken control of the Zaporizhzhia nuclear power plant, the largest in Europe.
No reactors were damaged during Russian assault
A fire started in a training center building when it was hit by a projectile during the Russian assault on the Zaporizhzhia nuclear facility Thursday night. The fire has now been extinguished and the nuclear facility is now under the control of occupying Russian forces. But the incident brought home just how realistic a much bigger nuclear catastrophe than Chernobyl could happen.
The head of the UN atomic watchdog, Rafael Grossi, told reporters on Friday that no damage was done to any of the six reactors at the nuclear power plant and there was no release of radioactive material. The facility is operating at reduced capacity with just one unit still running.
Damage could cause Fukushima-like nuclear disaster at Zaporizhzhia
Nuclear power plants are not islands that are self-sufficient, besides putting power on the energy grid they need to be able to take electricity from it. The operators of the Zaporizhzhia nuclear power plant have taken offline all but one of the six reactors on site. Should the final reactor be turned off the facility would need external electricity to keep the pumps for the cooling systems running.
This was the problem in 2011 when a massive earthquake and tsunami damaged the Fukushima Daiichi cooling pump system. That resulted in meltdowns in three reactors at the nuclear facility and the release of enormous amounts of radioactivity. That radioactive fallout spread across the entire Pacific Ocean to greater and lesser degrees. In the case of the Zaporizhzhia nuclear power plant melting down the radiation would travel with the winds. Relatively high amounts of radiation from Chernobyl were found in Austria to the west, Norway to the North and over to the Volga River in the east.
Chances of Zaporizhzhia nuclear facility meltdown
Some of the risks present at the Zaporizhzhia nuclear power plant would be that the fighting disconnects the facility from the power grid or that damage causes the cooling tanks to empty according to James Acton, co-director Nuclear Policy Program at the Carnegie Endowment for International Peace, speaking on the Rachel Maddow Show.
From what he could see, the weapons being used in the fight around the Zaporizhzhia facility didn’t appear to be sufficient to harm the spent fuel pools. If they were to drain though that could result in a meltdown of the radioactive material contained in them causing the expulsion of large amounts of radioactive isotopes into the atmosphere.
His bigger concern was the three reactors that were still running at the time of the assault. Since then, according to reports two of the reactors have been scrammed. The coolant in a reactor reduces relatively quickly to a temperature where it doesn’t boil, in the case of Fukushima’s Kashiwazaki-Kariwa 7 nuclear reactor within 16 hours of the automatic shutdown kicking in. However, Scott Burnell, public affairs officer at the US Nuclear Regulatory Commission, told Scientific American in the event of a power outage operators would have less than 24 hours to get the pumps running again before the radioactive fuel would meltdown.
It takes a long time for the fuel to be cold enough to be removed from the cooling pools, around five years according to a briefing by Greenpeace on the hazards at Zaporizhzhia plant. As of 2017 there were 855 tons reactor core fuel in spent fuel pools that are “highly vulnerable.” Were the cooling pump system to fail the pools risk overheating and evaporating. That could lead to metal cladding on the fuel rods igniting and releasing most of the radioactive material.
The nuclear power plant staff and emergency crews are working in a war zone
Another concern voiced by Acton is that if there were an emergency at the facility the first responders could potentially be caught in crossfire from the conflict, not to mention that they will be occupied with other emergencies related to the conflict. Also, nuclear power plants are very complex systems and the highly-skilled employees face the same danger.