Russia’s full-scale invasion of Ukraine in February 2022 has centred concerns on the threat that militaries pose to nuclear installations. In the wake of that on-going conflict, a new paper from the UK defence and security think tank the Royal United Services Institute (RUSI) explores these themes with the objective of assessing the implications for nuclear safety and deriving potential mitigation strategies.
As more countries become interested in pursuing nuclear energy as a source of clean and sustainable power, and as non-proliferation norms are increasingly challenged, the probability that nuclear installations will find themselves the targets fi or unintentional victims fi of the use of military force could increase. While emphasising that such military activity should not be normalised, the report argues that political and military leadership must nonetheless be ready to anticipate, mitigate and respond to potential future military attacks on nuclear installations.
The author, Darya Dolzikova, notes that while Ukraine’s situation is unique, the threat of military strikes on nuclear facilities is nothing new. Military force has been used or seriously considered against and in the vicinity of nuclear installations on multiple occasions before and stretches back to the earliest days of the nuclear era. Between 1942 and 1943, for example, Allied forces carried out a series of operations targetting the Vemork heavy water production plant in Norway that was being used as part of a German effort to build a weapon. The facility was ultimately destroyed in a bombing raid in November 1943.
Since then, Iraqi strikes on Iran’s Bushehr Nuclear Power Plant (at the time still under construction), Israeli attacks on Iraq’s Osirak reactor in 1981 and Israel’s bombing of Syria’s Al-Kibar reactor in 2007 are some of the better-known examples and in many other instances, attacks have been considered but not executed.
Military drivers for nuclear targeting
The paper outlines five contexts in which military force may be used or threatened to be used against nuclear installations. These are:
- As a counterproliferation tool
- For energy disruption purposes
- For area denial
- To generate escalatory, deterrent or coercive effects
- When a nuclear site is encountered on an axis of advance or during a broader military operation.
Counterproliferation objectives have historically been a prevalent driver for the use of military force against nuclear facilities but success as a counterproliferation tool varies on a case-by-case basis fi from a limited roll-back of a nuclear programme to completely disabling a country’s ability to continue its pursuit of nuclear weapons. Military strikes on facilities can also demonstrate the attacking state’s resolve to do what is necessary to prevent the emergence of a nuclear weapons capability.
However, the prevalent opinion suggests that military force is limited in its effectiveness as a counterproliferation tool and fi in isolation fi is best-suited to delaying, rather than outright eliminating any nuclear ambitions. Counterproliferation strikes may be carried out against a range of installations across the nuclear fuel cycle, each presenting unique risks to civilian populations and the environment.
Russia’s military advance on and occupation of Ukraine’s Zaporizhzhia nuclear power plant (ZNPP), in contrast, appears to have been driven by an intention to disrupt and eventually co-opt the energy generating capacity of the plant. The targeting of enemy energy generation and distribution infrastructure is well established in the military doctrine of many alliances and states fi including those of NATO. The report argues that the expected growth of the importance of nuclear power in the global energy mix in the coming decades may therefore increase the likelihood that future armed conflict will see greater targeting of nuclear energy infrastructure. This may not necessarily entail direct attacks on nuclear reactors but on auxiliary systems fi such as the water and electricity supply fi under the erroneous assumption that such attacks carry limited risk.
It is only partially true, the paper says, that attacks on supporting and transmission infrastructure are lower risk: these systems are all critical for the safe operation of a plant. A loss of off-site power (LOOP) incident, a loss of coolant accident (LOCA) or a station blackout (SBO) (when the station loses access to both off-site power and emergency generators) can have catastrophic results for a nuclear plant. This is something that the IAEA has repeatedly drawn attention to in the context of the war in Ukraine. The IAEA has highlighted the risk to nuclear safety posed by the frequent disconnection of Ukraine’s nuclear power plants, and the ZNPP in particular, from off-site power supply and the risks of potential coolant loss following the draining of the Kakhovka reservoir. Off-site power and water supply are critical for the maintenance of a plant’s safe and secure operation.
Attacks on nuclear facilities may also be carried out with the express intention of releasing radioactive or other toxic material as an area denial strategy. Radiological or chemical contamination of territory complicates and delays an adversary’s military operations in the affected area. However, most militaries have at least some ability to shield against CBRN (chemical, biological, radiological and nuclear) hazards and to continue operations in a contaminated environment fi particularly if a mission is critical. As such, ultimately, the effectiveness of radiological or chemical contamination for area denial is likely to be limited.
Due to the psychological impact of radiological hazards among the general population, attacks and threats of attack on nuclear installations may also be used for escalatory, deterrent or coercive purposes and as a ‘half-step’ between the use of conventional weapons and a nuclear weapons attack.
Short of attacking nuclear installations as a primary target of a military operation, militaries may also encounter and need to contest nuclear facilities on an axis of advance during a land invasion or may be required to carry out air campaigns against territory where nuclear sites are present. Militaries fi supported by relevant national authorities fi must therefore ensure they have the necessary expertise and capabilities and have conducted the necessary operational planning to be able to safely operate around nuclear facilities if this becomes necessary.
Mitigating risks from conflict
Given the various operational and strategic drivers for the use of military force against nuclear installations, the paper argues that a number of considerations become prevalent in managing and mitigating related nuclear safety risks.
These include:
- Strengthening understanding of, and compliance with, existing international legal principles and norms that restrict the use of military force against and near nuclear installations. This is a key measure to reduce risks. It may include developing additional guidance on the operationalisation of existing legal provisions and considering how legitimate military objectives may be pursued while maintaining maximum respect for nuclear safety. These may be developed by individual governments or groups of governments, or by international organisations, such as the International Committee of the Red Cross. Ensuring that these principles and their operationalisation are understood and respected at all ranks of a military force is also critical. Clear demonstrations of political commitments to existing restrictions and norms relating to attacks against nuclear facilities should be pursued. There are instances when military force may be used against, or in the vicinity of, nuclear installations for the pursuit of legitimate military objectives.
The Seven Indispensable Pillars and Five Concrete Principles for Nuclear Safety and Security articulated by the IAEA since the start of the war in Ukraine offer a useful starting point for establishing best practices for nuclear safety and security in warzones, the report says.
Reiterating commitments to existing legal provisions and broader norms, and calling out states that do not respect these, is important for making sure that the use of military force that threatens the safety of nuclear installations and poses a risk to civilians is not normalised. However, some states may still choose to disregard their International Humanitarian Law (IHL) obligations or to find ways to justify their actions even when such justifications are unconvincing or disingenuous.
- Considering options for strengthening passive defences around nuclear installations and auxiliary systems and equipment which support the safe operation of nuclear facilities (including auxiliary elements like water supply systems and electrical infrastructure). Most nuclear power plants operating today are already protected by reinforced concrete containment structures, making them challenging, although certainly not impossible, to penetrate. Constructing thicker containment structures over existing reactors that already benefit from reinforced containment would be a resource-intensive undertaking which would be incommensurate with the risk of an accidental strike and ineffective against an adversary determined to penetrate the reactor core to release radioactive material.Even in the most economically advanced or security-minded states, resources are not unlimited; this is likely to be especially true in the context of a broader military conflict, when already-limited sources must be allocated across a range of defence and security priorities. In all cases, then, additional physical protection would be subject to costfibenefit considerations and would be dependent on the extent and nature of the threat faced by a given state. For instance, it may be reasonable to expect that Ukraine or even Finland would expend the necessary resources to strengthen the containment structures around their wet spent fuel storage facilities, but similar measures would seem excessive for Canada or the UK. Beyond-Design Basis Threat (DBT) process and broader national-level risk assessments must therefore take into account the likelihood of potential military attacks on their nuclear sites by hostile states. Furthermore, some preventive and mitigation measures may have unintended consequences that could, in fact, increase other undesirable consequences of attack or make attacks more likely.
Additionally, an overly cautious approach to risk management fi for instance, foregoing nuclear energy altogether out of a fear of possible military threat fi may have other undesirable and unnecessary economic, environmental and political drawbacks. As such, the departure point for any risk-mitigation measures should be a realistic assessment of the precise nature and degree of risk that a given state’s nuclear infrastructure is likely to face from military threats.
The paper adds that passive defences may need to be supported with active defence measures in the instance of an active conflict, including the deployment of layered and distributed air defence, for example. However, the deployment of military capabilities near to nuclear installations may also have the unintended consequence of increasing the risks to facilities.
- Creating redundancy in and decentralising nuclear installations and related networks. This may help shift the costfibenefit calculus for an attacking state by increasing the number of targets that need to be attacked to have meaningful effects on a system and reducing the effects of single strikes. In the context of nuclear energy generation, this may include a shift away from large gigawatt-scale reactors towards the deployment of small modular reactors. However, decentralisation may also have the unintended consequences of increasing the risks of hazardous material release and harm to civilian populations by increasing the number and distribution of facilities containing toxic materials.
- Improving whole-of-society resilience to nuclear safety incidents, including through efforts to raise levels of emergency preparedness, risk awareness and education on nuclear safety among the public and political leadership. This should involve the pre-emptive formulation of risk and crisis communication strategies, as well as tools for countering disinformation and misinformation, which prioritise the establishment of trust between the population and authorities, and should also offer clear information and instructions. Any such efforts must be commensurate to the risk facing a given state and population, and will have to be balanced against the need to avoid alarmism and the risk of inciting unnecessary anxiety.
Responding to the potential for conflict
Militaries that are determined to respect the principles of international law and the safety of civilians and the environment more broadly should have the necessary guidance and tools to pursue legitimate military objectives safely. At the same time, countries should be prepared to protect and ensure the nuclear safety of nuclear installations that may be targeted by states that do not share a similar respect.
Considering the operational and strategic logic behind such military activity, as well as its likely consequences, can clearly help political and military leadership prepare to defend against related threats and mitigate risks.
As the number of nuclear installations around the world is expected to grow, militaries, national and international policymakers, and regulators need to consider the possibility that militaries may increasingly run the risk of encountering and having to operate or contest control of nuclear sites in the course of military operations.
The paper concludes that thoughtful management of risk and corresponding trade-offs requires an understanding of the motivations for an attack on any given facility. Considering those consequences of an attack that are of greatest concern and the best approaches to mitigate them can therefore help with the prioritisation of risk-management efforts to appropriately and effectively address both the incentives and consequences of a potential attack.
