Russian attacks on energy: why is it dangerous for NPPs?
Authors: Jan Vande Putte and Shaun Burnie, nuclear specialists, Greenpeace Ukraine
Every night, Russians attack civilians in Ukraine with explosive drones. This is a terrible threat to human life, but there is another unprecedented threat that has the entire Greenpeace international team concerned.
Recently, representatives of the Ukrainian government and president Zelenskiy said that according to intelligence, Russia is preparing attacks on Ukrainian nuclear power plants. Furthermore, Russia has already destroyed most of the electricity plants in an attempt. With nuclear plants needing electricity for cooling, further attacks on power plants or the electricity grid is the equivalent of an attack on the plant itself. This is an unprecedented case when a state uses the most vulnerable objects in warfare - nuclear energy - to risk nuclear contamination, not only in Ukraine but on the European continent.
After the illegal occupation by Russia of the Zaporizhzhia nuclear plant, Ukraine still has nine operational reactors at the Rivne, Khmelnytskyi and South Ukraine plants. Each plant is loaded with hundreds of tons of highly radioactive core fuel.
These nuclear plants heavily depend on the stability of the electricity grid to assure that the water circulation pumps keep running to cool the hot nuclear fuel. Without this cooling, the fuel could melt within a matter of hours, even after the reactors would be shut down.
Not a single national nuclear power program in the world has been designed to cope with the scale of disruption the full-scale Russian war has inflicted on the territory of Ukraine. There is currently no existing safety analysis available for nuclear regulators worldwide that considers such a scale of a crisis Russia’s deliberate attacks has caused in a national electricity system and its consequences for nuclear power plant safety.
Obviously, the nuclear power plants have several back-up systems, such as diesel generators. But they need many thousands of litres of fuel every day, and fuel reserves are limited. Also, these generators could malfunction, especially if they would have to run for a longer period of time. Such "loss of offsite power" happened before, at the Zaporizhzhia plant already eight times since the full-scale invasion. Although this is a dangerous situation, the six reactors at the Zaporizhzhia plant have been in shutdown for two years now, and need much less cooling than the operational reactors.
Due to Russian attacks, Ukraine is at risk of a cascading system-wide black-out in a large part of the country. It is a situation when one or several nuclear plants suffer unplanned disconnection or rapid shutdown of a transmission circuit, known as trip or scram; it can also happen when key substations have been damaged or destroyed by Russian military strikes. This could push voltage and frequency beyond the margins, with no additional generation capacity available. This can then lead to other generation capacity to trip, leading to a cascade and a system-wide blackout. All four nuclear power plants in Ukraine could then lose their connection to electricity supply from the grid.
The big problem for this winter is that if Russia further damages the electricity system, that at some point, the remaining power plants would not be sufficient any more to avoid a system-wide blackout. This means that all power plants switch off in a large part of the country, which is very different from the power outages we now face. And in order to reboot the grid from zero (a so-called "black start"), you need enough hydro plants or coal or gas plants or industrial batteries. Nuclear power plants cannot do that. So our concern is that blackstarting might be difficult because not enough power plants are available any more. This would leave the nuclear power plants too long without external electricity supply, and diesel fuel for the emergency generators might run out. In a worst-case scenario, this could stop the cooling systems at nuclear power plants, leading to the release of large amounts of radioactivity at several nuclear plants, severely contaminating not only Ukraine, but also the European continent, at a scale many times worse than Fukushima or even Chornobyl.
In an important development, the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) announced on 6 September 2024, that the International Atomic Energy Agency had agreed to a request to expand the permanent monitoring mission in Ukraine to cover electrical substations. An IAEA inspection took place six days later at a substation already damaged by Russian military strikes. Unfortunately, since then the IAEA is not moving fast enough or decisively enough. The presence of the international agency could have a deterrent effect on Russia, especially because Russia is working with the IAEA to help support its nuclear exports around the world, something Greenpeace has many times criticised, but in this case it could give the IAEA some extra leverage on Russia, at least if the IAEA is willing to use it.
The IAEA presence at substations is however not sufficient. As most of the non-nuclear generation capacity that can support the stability of the grid has been destroyed or damaged by the Russian aggression, any further attacks on the generation capacity, especially the remaining hydro plants, is also a direct threat for the nuclear power plants.
It might sound bizarre that Greenpeace is calling to protect the operation of nuclear power plants, after all, we are an organisation opposed to nuclear power. But first, Ukraine needs all the production capacity it has to get through the next winter. This does not change the fact that the nuclear plants are the most vulnerable parts of the electricity system. The only reason they are still functioning is that Russia’s attacks on the three operational plants under Ukrainian control have been limited so far. So, we are trapped in continuing nuclear production for the moment to keep the grid functioning, not only to keep the heat on this winter, but also to keep the vital cooling systems of the nuclear reactors running. However, further attacks on substations or power plants could tip over the already fragile system, dropping Ukraine into a blackout and making it difficult to reboot the grid and possibly leading to multiple nuclear reactor core failures and massive radioactive contamination. This is a uniquely horrible trap.
What should be done? Many things are already done, just to mention the heroic workers that repair power plants and substations. But Ukraine urgently needs much more international support, this is a threat not only to Ukraine but to the European continent. That has not sunk in sufficiently at the other European capitals. We need to raise the level of awareness.
The number one demand to the international community is to put all possible pressure to stop any further Russian attack on Ukraine’s electricity system. This is the moment the IAEA needs to rise above its pro-Russian bias and fully use its leverage on Russia. Furthermore, massive international support in rebuilding and protecting the electricity system. Not by old Soviet technology with vulnerable large-scale power plants, but with small decentralised production units. Adding industrial Battery Energy Storage Systems which work well together with solar plants and wind farms. Getting out of the current nuclear danger zone might take several years, but this shift to a more resilient system will progressively improve the stability and much could be realised already within a single year.
The prosperous future of Ukraine beyond the war will be efficient, decentralised, resilient and renewable, including the export of electricity to the EU instead of today’s imports. That shift has already started, but we need to speed it up with far greater international support, in the interest of the entire European continent.