Purdue university demonstrates quantum-secure communications in a nuclear reactor

The Purdue University School of Nuclear Engineering, in collaboration with the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) and Toshiba, has successfully demonstrated quantum-secure communication within a nuclear reactor environment. The trial was conducted at Purdue University Reactor Number One (PUR-1), employing Toshiba’s Long Distance Quantum Key Distribution (QKD) technology. This achievement represents a significant step forward in the integration of quantum security into nuclear energy systems.

“The ability to maintain secure communications in reactor systems is critical to ensuring their resilience and safety,” said Dr Stylianos Chatzidakis, Assistant Professor at Purdue’s School of Nuclear Engineering. “Reactors, particularly microreactors deployed in remote areas, depend on continuous data exchange for monitoring, control, and safety operations. Cybersecurity breaches in such systems could compromise sensitive information or operational integrity, posing risks to public safety and energy security.”

The three-year project, funded by the Department of Energy through its Nuclear Energy University Program, demonstrates the application of quantum communication technologies to secure data transmissions in advanced nuclear reactors. This is particularly relevant for microreactors intended for deployment in remote or isolated locations, where conventional energy infrastructure may be impractical or unreliable.

Microreactors are gaining attention as viable solutions for delivering dependable, decentralised power in challenging environments such as off-grid communities, military bases, research outposts, and remote industrial facilities. Designed to be transportable and capable of autonomous operation, these small-scale reactors require robust cybersecurity to ensure safe and secure operations. The findings from this initiative offer valuable insights into improving the cybersecurity posture of next-generation nuclear energy systems.

Purdue’s PUR-1 reactor is the first nuclear reactor in the United States to be fully operated and controlled through digital systems, replacing traditional analogue dials and knobs with computer interfaces and Ethernet-based communications. Although other nations have implemented digital control systems in nuclear reactors, PUR-1 remains the only fully digital reactor licensed by the U.S. Nuclear Regulatory Commission. Its all-digital instrumentation and control system, effectively the reactor’s “nervous system" relies entirely on digital technology.

“PUR-1 is uniquely positioned to address challenges like this as the first fully digital nuclear reactor in the United States,” said Phil Evans, Senior R&D Staff Member at Oak Ridge National Laboratory’s Quantum Communications and Networking Group. “Equipped with state-of-the-art digital instrumentation and a digital twin, PUR-1 serves as a flexible research and education platform for exploring advanced technologies in reactor operation and cybersecurity,” Evans added.

Quantum Key Distribution, already employed in the banking sector and under consideration for applications in electric grid infrastructure and defence, offers a method of communication immune to conventional eavesdropping techniques. Unlike classical encryption, which relies on the computational difficulty of solving mathematical problems, QKD is grounded in the laws of quantum mechanics. It exploits the principle that measuring a quantum system inevitably disturbs it, thereby making any unauthorised interception of the encryption keys detectable.

“The fully digital architecture of PUR-1 makes it an ideal testbed for integrating and assessing quantum technologies in a realistic nuclear environment,” said Terry Cronin, Vice President of Marketing at Toshiba International Corporation. “This capability enables experimental validation of innovative solutions before they are scaled to larger or remote reactor systems. With QKD, we are addressing critical concerns by offering a level of security that is resilient against interception or decryption, now and in a post-quantum computing era.”

Toshiba’s Long Distance QKD technology enables the secure transmission of encryption keys using photons as quantum bits (qubits). Any attempt to intercept these qubits alters their quantum state, alerting both sender and receiver to the breach. This method provides unprecedented protection, especially against future quantum computers capable of breaking existing encryption standards such as RSA and ECC. By implementing QKD, critical infrastructure like nuclear reactors can maintain secure communications even in the face of emerging computational threats.