Engineers at the U.S. Department of Energy’s Argonne National Laboratory are conducting research to understand how insider actions could disrupt passive safety systems in next-generation nuclear reactors. This investigation is crucial as these systems are pivotal for reactor safety and are expected to be widely implemented in future designs, including small modular reactors.
Passive safety systems have demonstrated reliability in many operational reactors globally, supported by decades of data. As reactors evolve, understanding the vulnerabilities of these systems becomes increasingly critical. According to Darius Lisowski, group manager of reactor safety testing and analysis at Argonne, “We want to know what would cause these systems to not work… What could they do to make things break?”
Rather than treating sabotage as a theoretical risk, Argonne researchers are simulating real-world scenarios in their advanced experimental facilities. This proactive approach aims to identify potential insider threats before new reactor designs are finalized and licensed.
Stress-Testing Passive Safety Systems
The primary focus of this research is the Natural Convection Shutdown Heat Removal Test Facility at Argonne. This facility allows engineers to simulate how heat disperses through reactor systems when pumps and power are unavailable. Researchers examined various insider actions that could compromise safety, such as leaving access hatches open or intentionally blocking cooling pathways.
The project, which began over two years ago, involves collaboration with Sandia National Laboratories, Oak Ridge National Laboratory, and Idaho National Laboratory. The team first identified plausible sabotage scenarios and assessed their potential impact. Their findings were compiled into a significant report titled “Identifying Sabotage Risks and Adversarial Threats to Passive Decay Heat Removal Systems in Advanced Nuclear Reactors,” which was prepared for the International Atomic Energy Agency.
The researchers discovered that nuclear plants are designed with multiple layers of protection, including controlled access, alarms, and redundancy. These features make successful sabotage complex. Nonetheless, they concluded that addressing certain vulnerabilities early in the design process is essential.
Identifying and Addressing Weak Points
To explore these vulnerabilities, Argonne researchers recreated credible sabotage scenarios within their testing facility. They intentionally blocked cooling paths and left components unsecured to measure how the systems responded under stress. “Our research is relevant and applicable to every U.S. nuclear vendor out there,” stated Matthew Bucknor, Argonne’s international nuclear security lead.
The experiments do not target any specific reactor design or company, but instead focus on common features shared across various advanced reactor concepts. The team believes that identifying risks early can prevent small oversights from escalating into serious issues later on.
Lisowski emphasized that by integrating redundancy and focusing on the most severe threats, the team can enhance the robustness of passive safety features. “Design improvements will happen early, before the next generation of reactors goes into operation,” he added.
This research is funded by the National Nuclear Security Administration and has received ongoing support for further investigations. As countries increasingly turn to nuclear energy to address rising electricity demands driven by advancements such as artificial intelligence and data centers, the researchers assert that safety and security measures must evolve in tandem with reactor technology.
