Webinar Recap: Hidden Nuclear Risks? Understanding Nuclear Safety and Environmental Risks in North Korea

Moderated by ONN Engagement and Network Assistant Federica Petrucci,  the discussion brought together three members of the ONN Research and Analysis team: Jaewoo Shin, Analysis Manager, Elin Bergner, Research Coordinator and Nikita Degtyarev, Research Coordinator.

Audience Poll: What Are People’s Concerns Regarding DPRK Nuclear Risks?

Before the presentation, participants were asked which risks associated with North Korea’s nuclear programme concerned them most and which nuclear safety and environmental vulnerabilities they considered most significant.

Military escalation or miscalculation emerged as the leading overall concern, followed by nuclear weapons use. When participants were asked specifically about nuclear safety and environmental risks, insufficient information to assess the risks ranked first, followed by ageing facility infrastructure.

The results highlighted one of the central challenges explored throughout the webinar: significant uncertainties remain about current conditions inside North Korea’s nuclear facilities, even as the programme continues to expand and infrastructure ages. The discussion therefore turned to two practical questions: what can we still learn about these risks despite the information gaps, and what can be done now to better monitor, understand and prepare for them?

What stood out from the discussion?

• The most credible risks may be persistent and slow-moving rather than catastrophic. Across the nuclear fuel cycle, the research found stronger support for concerns such as ageing infrastructure, spent fuel and radioactive waste management, tailings and chemical hazards than for a sudden large-scale accident affecting the wider region. 
• Nuclear safety risks extend across the entire fuel cycle. The report examines three principal locations: Pyongsan, Yongbyon and Kangson, and considers risks across the nuclear fuel cycle. Different stages of the fuel cycle present different combinations of radiological, chemical and conventional hazards. 
• Governance can determine whether technical problems remain manageable or escalate. Historical evidence indicates that the DPRK has developed a formal nuclear safety framework and considerable technical expertise. At the same time, the available evidence cannot establish whether regulations are currently implemented consistently, whether deficiencies lead to corrective action, or whether the regulatory system has sufficient independence and authority. 
• Those closest to nuclear facilities face the most plausible environmental risks. Workers, nearby communities, local soil, groundwater and river systems are generally the most likely to be affected by the vulnerabilities identified in the report.  
• Transboundary impacts are possible, but the available evidence does not suggest they are the most likely outcome. Wider transport of radioactive or chemical material would generally require additional conditions such as specific meteorological circumstances. The research therefore places greater emphasis on local and near-site impacts than on catastrophic regional scenarios. 
• Uncertainty is itself an important part of the risk picture. Satellite imagery can reveal changes in infrastructure, waste areas, water systems, damage and repairs, but it cannot show the condition of equipment inside buildings, maintenance practices or how personnel would respond during an emergency. The report therefore distinguishes carefully between directly observed evidence, technical inference and plausible scenarios. 
• There are practical steps that can be taken now. The discussion highlighted the importance of sustained monitoring of facilities, waste areas, water infrastructure and environmental conditions; preserving the knowledge of former inspectors and technical personnel with first-hand experience in the DPRK; and preparing response capabilities before an accident or renewed international access occurs. 

Why Nuclear Safety in the DPRK Matters?

While discussions often focus on nuclear weapons, deterrence and regional security, the DPRK’s nuclear infrastructure has continued to operate and expand, creating safety risks that exist regardless of the diplomatic or military situation.

Jaewoo Shin explained that these risks matter first and foremost for workers, nearby communities and the local environment, which would likely be the first affected by many potential incidents. Under more severe circumstances, releases could also have wider regional implications. Nuclear safety is also relevant to the future of the nuclear programme itself: if inspections resume or future negotiations involve a freeze, dismantlement or other technical measures, understanding the condition of facilities and associated safety risks will be essential.

With independent access to North Korea’s nuclear facilities highly limited, the research therefore asks what can still be established from available evidence. It brings together multilingual open-source and archival research, satellite imagery, historical inspection and technical records, environmental pathway analysis and insights from experts with first-hand experience to identify credible vulnerabilities while distinguishing clearly between what is known, inferred and still uncertain.

What technical vulnerabilities exist?

Nikita Degtyarev examined credible failure mechanisms across North Korea’s nuclear fuel cycle, from uranium mining and milling to conversion and enrichment, reactor operations, spent fuel, reprocessing and radioactive waste. At Pyongsan, uranium milling produces large volumes of tailings and process water, creating potential risks from leakage, spillage, dust and chemical exposure. Conversion and enrichment activities introduce different hazards, as a loss of uranium hexafluoride containment could produce highly corrosive hydrogen fluoride as well as uranium-bearing compounds. At Yongbyon, the ageing 5 MWe reactor and the newer Experimental Light Water Reactor (ELWR) present distinct safety questions, while both depend on water-control infrastructure that has repeatedly experienced hydrological stress. Spent fuel and radioactive waste create additional longer-term concerns, including corrosion, contaminated pond water and sludge, and the potential for localised leakage from storage and waste systems.

Overall, the assessment highlighted a combination of ageing infrastructure, chemical hazards, gradual degradation and long-term spent fuel and waste management challenges. Severe accidents remain technically possible, but limited information about current facility conditions and safety systems makes their likelihood difficult to assess reliably.

How could a release become environmental exposure?

A central part of the research examined how radioactive or chemical material might move through the environment and who or what could be exposed.

Elin Bergner introduced potential environmental pathways through air, surface water, groundwater, soil and sediment, as well as agricultural systems. At Pyongsan, for example, leakage from uranium-processing infrastructure could affect nearby soil and potentially enter connected river systems. At Yongbyon, gradual leakage from spent fuel or waste systems could first affect nearby buildings, soil and groundwater, while a severe accident could create a broader atmospheric pathway. At Kangson, a loss of uranium hexafluoride confinement could create an immediate inhalation hazard and deposit uranium-bearing material on surrounding soil.

Importantly, these pathways represent technically plausible routes, not evidence that contamination or exposure has occurred. Actual consequences would depend on factors including the quantity and form of material released, geology, hydrology, weather and how surrounding land and water are used.

Looking Ahead

The webinar underscored that nuclear safety should not be treated as separate from wider efforts to understand and reduce nuclear risk on the Korean Peninsula. Ageing infrastructure, radioactive waste, environmental hazards and uncertainty about current safety practices may develop gradually, but their consequences could be long-lasting.

These risks also have implications beyond accident prevention. If international inspectors or technical experts are ever able to return to North Korean nuclear facilities, whether through verification or renewed technical cooperation, the physical condition of those facilities and the location and management of hazardous material will directly affect what can safely be done on the ground.

The report therefore calls attention to risks that are difficult to observe but should not be overlooked. Sustained monitoring, preservation of technical knowledge and advance preparation can help ensure that governments and international organisations are better equipped to respond to future incidents or opportunities for engagement.