The nuclear fuel recycling process involves multiple stages, from dissolving the used material in concentrated nitric acid to separating its constituent elements. Since these elements exhibit characteristic alpha radioactivity levels, precise measurement is essential for effective separation. The final phase relies on in situ alpha radioactivity measurement via a diamond sensor designed to withstand high pressure, temperature, and acidity.
Alpha particle detection is achieved through an active diamond layer that converts energy into electrical signals. The sensor’s performance depends directly on the diamond’s purity, homogeneity, and defect-free structure. An optimal sensor combines detection efficiency, signal stability, minimal current leakage, and operation at up to 80°C without performance loss.
Our monocrystalline diamond detectors demonstrate, x9, greater charge collection efficiency compared to previous detectors.
Additionally, the sensor’s sealing mechanism ensures the system’s overall leak-tightness. To refine the industrial separation process, our teams optimized both the sensor (by developing four diamond variants) and its mounting methods (four techniques using gaskets, resins, and brazing).
This research yielded a new protocol for growing monocrystalline diamonds that balances performance, simplicity, speed, and cost. A novel sensor design—featuring a durable, supply-chain-resilient polymer gasket—was selected. The project is now turning its focus to manufacturing and characterizing a full prototype for real-world testing.
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For nuclear fuel recycling, a monocrystalline diamond alpha radioactivity sensor offers remarkable efficiency and durability
