A scintillating aerogel for monitoring radioactive gas emissions

A scintillating aerogel enabling real-time measurements with glorious sensitivity to sure radioactive gases, important to monitoring the right functioning of nuclear energy crops, has simply been developed by a gaggle of physicists, chemists, and meteorologists from the CNRS, the College Claude Bernard Lyon, the CEA, and the ENS de Lyon.

This methodology proposes an alternate that’s each faster and extra economical than the present ones, which are sometimes advanced and expensive. The research was revealed within the journal Nature Photonics on 2 September 2024.

Tritium (³H), krypton-85 (⁸⁵Kr) and carbon-14 (¹⁴C) are among the many commonest radioactive gases emitted by the nuclear industry throughout electrical energy manufacturing or recycling of radioactive waste. Though these radionuclides don’t current a significant hazard, their accurate measurement is a key indicator for monitoring the right functioning of nuclear energy crops and stopping accidents.

Nonetheless, the radionuclides are amongst these whose radioactive decay doesn’t include gamma ray emissions, they’re pure beta emitters, and require particular procedures for detection and measurement. The applied sciences used at this time are primarily based on the rules of both gas-liquid mixing or gas-gas mixing, and stay expensive and complicated.

Moreover, they can not distinguish between radionuclides shortly, they generate waste, and usually are not significantly efficient for a number of the radioactive gases below evaluation.

Analysis carried out by scientists from the Institute of Gentle and Matter (ILM—CNRS/College Claude Bernard Lyon 1), the ENS de Lyon Chemistry Laboratory (LCH—CNRS/ENS de Lyon/College Claude Bernard Lyon 1) and the Henri Becquerel Nationwide Laboratory (CEA) has led to the event of a real-time detection expertise primarily based on gas-solid mixing that’s each dependable and cost-effective.

It’s primarily based on synthesizing an aerogel about one centimeter thick and some centimeters in diameter, utilizing nanoparticles of scintillating supplies about 5 nanometers in dimension. This composite has a extremely porous construction just like a sponge, consisting of solely 15% solids, whereas remaining clear.

This distinctive structure permits the fuel to diffuse very simply. When the fuel penetrates the scintillation vial and comes into contact with the aerogel, the latter converts the vitality produced by the emission of electrons throughout radionuclide decay into visible light. This flash of sunshine is straight away captured by a extremely delicate detection system that may measure every photon nearly instantaneously.

Superb-grained evaluation of those gentle emissions helped develop an modern methodology to differentiate and measure the pure beta emissions of various energies on-line, corresponding to that of tritium and krypton-85 inside the identical fuel pattern. These discoveries had been developed and confirmed each theoretically and experimentally due to a state-of-the-art experiment on radioactive gases.

The detection effectivity was 20% for tritium and practically 100% for krypton. As well as, as a result of it isn’t contaminated by the radioactive gases, the inorganic scintillator is reusable, thereby limiting waste, not like different strategies.

This new method to detecting radioactive fuel has paved the way in which for the widespread use of sensors for monitoring civilian nuclear actions. It might be prolonged to different beta-emitting radionuclides which can be important for space monitoring, corresponding to carbon-14 (¹⁴C), xenon-133 (¹³³Xe), and argon-37 (³⁷Ar), which might broaden its scope to incorporate civilian, medical, and army functions.

This discovery was made as a part of the European SPARTE undertaking, and has led to a number of patent functions.