BY Dmitry Gorchakov

As the Ukrainian army’s cross-border incursion into Russia’s Kursk Region rages into its fourth day, the objectives of the surprise attack have been grist for media speculation. Some have suggested the Ukrainians might target the Kursk Nuclear Power Plant as payback for Russia’s long-running seizure of Ukraine’s Zaporizhzhia nuclear plant.

It’s difficult to say how likely such a scenario is, but should it come to pass, it makes sense to briefly analyze the problems, risks, and dilemmas that would come of such an attack.

The specifics of the Kursk NPP

The Kursk Nuclear Power Plant is the closest Russian nuclear power plant to the Ukrainian border—just 60 km away. The idea that it could be at risk of attacks during a full-scale war became evident in the early months of Russia’s full-scale invasion of Ukraine. The Russia seizure of the Zaporizhzhia plant and territory of Chernobyl, followed by vigorous Ukrainian counterattacks, made clear that this would be a full-scale and potentially prolonged war with consequences for Russian territories.

As the war has dragged on, we have seen the Kursk NPP and its satellite city, Kurchatov, fall under attack by Ukrainian drones. No other Russian nuclear plants, which are much farther from the border and the front line, have been subjected to such attacks.

Currently, only two units are operating at the Kursk NPP, Units 3 and 4, each with a capacity of 1,000 MW. The first two units were shut down in 2021 and early 2024, respectively, after 45 years of operation. Fuel has been unloaded from Unit 1. All of the Kursk NPP’s units are RBMK-1000 reactors, similar to those used at Chernobyl. It’s worth noting that RBMK reactors — unlike the VVER-1000 reactors installed at the Zaporizhzhia NPP — are less protected against external threats. Much of our risk analysis for the Zaporizhzhia NPP during its seizure, presented in our 2023 report “The Radiation Risks of Seizing the Zaporizhzhia Nuclear Power Plant,” was based on a comparison of the characteristics of these reactor types.

Let’s examine some of the technical points and key vulnerabilities of the RBMK design. First, the lack of concrete containment structures (domes) over the reactor compartments makes RBMK reactors more vulnerable to damage from accidental or deliberate attacks by missiles, bombs, and artillery. Small arms or even light drones pose less danger.

Second, RBMK’s are single-circuit, boiling water reactors. This means that the same water and steam that pass through the reactor core go directly to the turbine, without intermediate circuits and heat exchangers. Therefore, depressurization and damage to the machine hall could lead to a radiation release. This release wouldn’t be as large as in a reactor accident, as it wouldn’t involve fuel discharge — but it would nonetheless be a radiological incident. Undoubtedly, if there is any risk of the plant being seized, the reactors must be shut down and cooled. This would reduce the risk of accidents and their possible consequences during military operations around the facility. We’ll recall that at the Zaporizhzhia Nuclear Plant, several reactors continued operating for six months after the plant’s seizure in 2022 — and this was extremely dangerous.

Additionally, the construction of the Kursk NPP-2 with two VVER-TOI units, which are intended to replace the old units of the Kursk NPP as they are decommissioned, is already nearing completion. The units of Kursk NPP-2 are reference units of the VVER-TOI, an improved and more powerful version of the VVER-1200 units. Based on this design, Rosatom plans to build new units within Russia and offer them for export in the future. Commissioning work has already begun at the Kursk NPP-2 plant. Fresh nuclear fuel has already been delivered to the first unit, and reaching the first criticality is planned before the end of the year. Clearly, the Kursk NPP-2 is an extremely important facility for Rosatom and the largest nuclear construction project within Russia.

The seizure of nuclear facilities during war

Any armed seizure of a nuclear facility is unacceptable and extremely dangerous. Formally, this can be considered nuclear terrorism according to the International Convention for the Suppression of Acts of Nuclear Terrorism. Unfortunately, the reality of recent years in Europe has shown that many of the formulas embedded in international agreements, as well as many international organizations in general, are incapable of addressing, much less preventing, the modern challenges we are facing.

We are witnessing the largest war in Europe since World War II, between two major countries with a significant number of nuclear facilities. As the front line shifts in one direction or another, these facilities may end up on captured territory. We have already observed the seizure of at least three nuclear facilities during Russia’s aggression against Ukraine—a research reactor in Sevastopol during the annexation of Crimea in 2014 (which has not been operational since), the capture and subsequent liberation of the Chernobyl NPP in the spring of 2022, and the ongoing  two-plus year occupation of the Zaporizhzhia NPP. Based on these examples, some conclusions can be drawn about the possibility of such seizures and the risk that attend them. These can be formulated into several recommendations:

1. is unequivocally clear that the most dangerous and unacceptable scenario for seizing a facility is an assault involving heavy ordinance—exactly what happened in March 2022 during the capture of the Zaporizhzhia NPP when Russian troops fired tank shells near the plant and upon its grounds against much less heavily armed defenders. 
2. It is unacceptable to turn a nuclear facility into a military base or fortified area, to station troops and heavy equipment there, or to fire from its territory or nearby under its cover. All of this, unfortunately, could make the facility a legitimate military target, despite all the risks that come with attacking such a facility. These same requirements are reflected in the five principles for protecting the Zaporizhzhia NPP proposed by IAEA Director General Rafael Grossi in 2023. Therefore, the defense of nuclear facilities during full-scale war should be conducted outside their territory, preferably at a distance, to prevent the enemy from approaching them.
3. Should capture of a nuclear facility become inevitable in the face of superior enemy forces, negotiations to surrender the plant should be held to surrender the plant, rather than defend it to the last and attempt to turn it into an impregnable fortress, thereby risking a devastating assault. It was thus— with relatively little bloodshed —that the nuclear facilities in Sevastopol and the Chernobyl NPP were surrendered, without shots and without the threat of military actions near the facility.
4. It is also unacceptable, after gaining control of a facility, to turn it into a fortified area in anticipation of counterattacks and attempts to retake it, hiding equipment, weapons, and soldiers there. This is what Russia did with the Zaporizhzhia NPP, and it would be very undesirable if the Ukrainian Armed Forces, should they seize the Kursk NPP, were to repeat that history. Ukraine, during its offensive, is not doing anything that Russia has not done during this war. But it should not emulate war criminals.
5. If we are now forced to discuss the seizure of nuclear facilities, a reality brought about by the years of war in Ukraine, it must be acknowledged that the safest way to do this would be to simply surround and bypass these facilities with advancing troops, without engaging in combat on their territory or nearby, followed by negotiations on the status of the facility. Ideally, these negotiations and the oversight of their outcomes should be conducted with the participation of international organizations such as the IAEA.

Undoubtedly, all nuclear facilities seized during the war must eventually be returned to their rightful owners, and all parties involved, along with international organizations, must make every effort to prevent nuclear and radiological incidents during wars. Russia must end this aggressive war and return all seized territories and nuclear facilities on them to Ukraine.