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Detection of radionuclides in the atmosphere: aerosol and gas |
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Prototypes of aerosol and gas radionuclide stations have been designed and developed by the CEA. The CEA's industrial partner, SFI-Environnement SA, was in charge of industrialization. |
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 Aerosol radionuclide stations |
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Systems for sampling the aerosols in the air and measuring radioactive isotopes.
Principle
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Aerosol sampling of a large quantity of air with highly efficient filter. |
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Filter compression to optimize measurement. |
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γ spectrometry-based detection of natural and artificial radioactive isotopes. |
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Performance
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Daily air volume processed: 14 000 m³. |
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Particle volume concentration factor: 4.108. |
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Examples of minimum detectable activity: 140Ba and 137Cs ≤ 30 µBq.m-3. |
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Data transmission every 24 hours. |
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Aerosol sampling system. Tahiti station (CTBT FRP27). |
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Gas radionuclides stations: SPALAX |
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Inline automated sampling system with analysis of xenon contained in the air and radioactive isotope measurement system.
Principles:
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Air sampling, |
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Elimination based on permeation of water vapor, oxygen and carbon dioxide through a nitrogen producing membrane, |
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Xenon and radon separation, |
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Xenon concentration by selective adsorption-desorption on activated carbon, |
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γ spectrometry detection of 4 xenon radioactive isotopes. |
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Performance
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Daily air volume processed: 85 m³. |
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Xenon volume concentration factor: 2.106. |
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Radon decontamination factor > 105. |
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Example of minimum detectable concentration: 133Xe ≤ 0,5 mBq.m-3. |
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Data transmission every 24 hours. |
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SPALAX, gas radionuclide station. |
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Example of atmospheric concentration measurements of the 4 xenon radioactive isotopes (131mXe, 133Xe, 133mXe, 135Xe) taken with an operational station. |
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