Device for realizing passive combined collection of atmospheric radioactive tritium and carbon

Abstract

The invention belongs to the technical field of radioactive gas sampling, and relates to a new device for realizing passive combined collection of atmospheric radioactive tritium and carbon. The device consists of a top cover assembly, a 14CO2 adsorption chamber assembly, an indicator chamber, an HTO adsorption chamber, a diffusion chamber, a bottom cover, a sealing assembly and a filter membraneassembly. According to the device provided by the invention, based on the atmospheric diffusion theory and Fick's first law of diffusion, an adsorbent material with good an enrichment effect on environmental water vapor and carbon dioxide is placed in a sampler to realize high-efficiency enrichment of a target gas; and through a computational fluid dynamics (CFD) simulation technology, an appropriate sampling diffusion length is determined to ensure the stability of the sampling efficiency. Field tests show that the device can meet the requirement of stable sampling under general environmentalconditions. The device does not need power support for the collection of environmental water vapor and carbon dioxide, and is economical and convenient, and the maximum relative deviation between a collected sample measured and a result monitored by an existing active device is 16%, so that the device can meet requirements of investigation of large-scale environmental level radioactive tritium and carbon.

Description

technical field [0001] The invention belongs to the technical field of radioactive gas sampling, and in particular relates to a device capable of realizing passive combined sampling of atmospheric radioactive tritium carbon. Background technique [0002] The prior art is disclosed 3 H. 14 As the two most critical radionuclides, C is the key target of monitoring radioactive pollutants around nuclear facilities. Although the β-rays produced by their spontaneous decay will not directly cause additional external radiation hazards to humans due to their low energy, these two types of nuclide have strong isotope exchange capabilities and can replace stable isotopes of hydrogen and carbon in substances and transfer them through the food chain. , air inhalation and other ways are ingested into the human body, causing internal exposure hazards. atmosphere as 3 H. 14 Important storage media and transport channels for C compounds, in the atmosphere 3 H. 14 C compound concentrati...

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Problems solved by technology

Although there are several passive accumulative models at home and abroad 3 H sampler, but the above research is not yet comprehensive and systematic. The main deficiencies are: ① lack of reliable scientific basis for the design of the geometric structure of the sampler; ② lack of systematic basis for the selection and quantification of adsorbent materials for the sampler; Discuss the impact of meteorological factors on the acquisition performance, ④ lack of systematic consideration of the influence of the saturation characteristics of the adsorption material on the results during the acquisition process, ⑤ lack of consideration of the relationship between aerosol deposition and the orientation of the sampling port, etc., so that it is still impossible to accurately quantitatively evaluate the Key technical parameters such as the control of the adsorption end point in the environmental application process, let alone judge its pros and cons and environmental applicability

research shows, 3 H. 14 The sample collection of C is similar in principle and methodology, but there is no passive sampler at home and abroad that can simultaneously collect environmental radioactive tritium carbon. In practical applications, two passive samplers are arranged at the same sampling point It will also cause a waste of resources. Therefore, based on the status quo of the prior art, the inventor of the present application intends to provide a new device that is easy to use, high in accuracy, and can simultaneously passively collect radioactive tritium carbon in the environment. In the atmosphere around nuclear facilities 3 H. 14 Routine monitoring and emergency monitoring of C

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