Real-time detection and discrimination of radioactive gas mixtures using nanoporous inorganic scintillators

The nuclear industry's expansion to encompass carbon-free electricity generation from small modular reactors and nuclear fuel reprocessing necessitates enhanced detection and monitoring of pure beta-emitting radioactive elements such as 3H and 85Kr; this endeavour is crucial for nuclear safety authorities tasked with environmental monitoring. However, the short range of electrons emitted by these gases makes detection challenging. Current methods, such as ionization chambers and liquid scintillation, do not offer at the same time good sensitivity, real-time analysis and ease of implementation. We demonstrate an approach using a gas–solid mixture to overcome these limitations. We synthetized a transparent and scintillating nanoporous material, an aerogel of Y3Al5O12:Ce4+, and achieved real-time detection with an efficiency of 96% for 85Kr and 18% for 3H. The method reaches a sensitivity below 100 mBq per cm3 over 100 s measurement time. We are able to measure simultaneously as mixtures containing both 3H and 85Kr a capability not possible previously. Our results demonstrate a compact and robust detection system for inline measurement of strategic radioactive gases. This combination of concept and method enhances nuclear power plant management and contributes to environmental safeguarding. Beyond the detection issues, this concept opens a wide field of new methods for radionuclide metrology. Using a gas–solid mixture approach, researchers used a transparent, scintillating nanoporous material for real-time detection of 85Kr and 3H, two pure beta emitters. They also simultaneously measure a mixture of them. The broadly applicable approach may be useful for nuclear industry and environmental safeguarding.