Natura Resources LLC has received a $350,000 DOE Gateway for Accelerated Innovation in Nuclear (GAIN) voucher to support a planning project for a novel irradiation experiment at the High Flux Isotope Reactor at the Department of Energy’s Oak Ridge National Laboratory. A GAIN voucher enables private companies to access national laboratory expertise and advanced resources. This mechanism helps small companies collaborate with experts and share costs.
The project aims to develop a graphite qualification program that meets the American Society of Mechanical Engineers Boiler and Pressure Vessel Code requirements.
Graphite is used to slow neutrons in nuclear reactors and is an essential material in reactor design. Understanding how graphite degrades over time under high-dose, high-temperature and corrosive conditions is vital to ensure reactor performance and efficiency. This work will develop the plan for a future experimental program that will inform how reactor components are designed, monitored and maintained over long periods of operation.
A key part of the research involves irradiating graphite in a specially designed capsule filled with molten salt that contains depleted uranium fluoride. The molten salt acts like a reactor coolant by transferring heat, while the depleted uranium fluoride simulates the reactor’s fuel environment and avoids complications with fissile materials. Beryllium is used to help manage the neutron flow, ensuring the conditions inside the capsule mimic those in a reactor core.
The experiment will be conducted inside the flux trap, which is engineered to concentrate neutron radiation so that even a 24-day exposure can replicate the effects of a full year of reactor operation.
“We’ve never put a capsule of this engineering complexity in the flux trap before,” said Anne Campbell, project lead at ORNL. “This is not just a routine program; it is a next-level effort and requires significant planning to ensure the safety of employees and HFIR.”
In addition to meeting the technical challenge of irradiating graphite in a unique environment, the program will develop the experimental program that will provide insights into changes in the graphite over time. Data on structural degradation and behavioral shifts of graphite under radiation will allow engineers to improve reactor designs and refine monitoring techniques. Understanding graphite behavior helps designers predict when reactor components might need replacement or repair, ensuring ongoing safety.
By establishing safety standards for graphite use, the project lays the foundation for future reactor designs. Its focus on gathering essential data to qualify graphite for harsh reactor conditions supports the broader goal of achieving resilient and efficient nuclear energy systems. –Scott Gibson
UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.
