An ORNL-led effort has validated a prototype high-temperature fission chamber that can operate up to 800 degrees Celsius (1,472°F) for use in advanced nuclear reactors.

The project aligns with the DOE Gateway for Accelerated Innovation in Nuclear (GAIN) program and the Office of Nuclear Energy’s Advanced Sensors and Instrumentation initiative, aimed at removing deployment barriers for advanced nuclear systems.

Testing demonstrates the sensor’s resilience to extreme heat, supporting the feasibility of reliable sensors in hotter, more efficient next-generation reactors.

Engineers from ORNL and Curtiss-Wright designed a custom rig to simulate harsh reactor environments, pushing the sensor to its limits and validating operation under high heat and irradiation.

Fission chambers are primary neutron sensors essential for initiating reactors and monitoring power, and new high-temperature designs are needed for concepts like molten salt and high-temperature gas-cooled reactors.

Validation occurred during a weeklong irradiation at The Ohio State University Research Reactor, with the sensor maintaining performance across reactor power levels and showing no degradation at high temperature.

A Oak Ridge National Laboratory team evaluated a next-generation high-temperature fission chamber designed to monitor neutron output in advanced reactors.

ORNL stresses that recreating extreme environments is critical for validating new reactor components and building confidence in their performance.

This development supports moving toward reliable, clean, and powerful energy from advanced nuclear designs.

Successful prototype validation provides a data-backed foundation for licensing, commercialization, and deployment of high-temperature neutron sensors in next-generation reactors.

During testing, the sensor operated at temperatures up to 800°C while exposed to intense radiation, delivering steady data across all power levels.

The Curtiss-Wright-developed prototype was tested at Oak Ridge and simulated harsh reactor conditions using a custom rig and OSU’s research reactor over a one-week period.