in the air 85 Automatic continuous measurement system for kr gas separation, extraction and content

Abstract

The invention discloses an air 85 An automatic continuous measurement system for Kr gas separation, extraction and content. The whole system is evacuated through a vacuum device, and the air sample gas is passed into the water removal device to remove water and carbon dioxide, and then enters the liquid nitrogen soaking chamber at a suitable flow rate through the first mass flowmeter. The first activated carbon low temperature cold trap, after the sample is distilled for a certain period of time, the first activated carbon cold trap is heated through the temperature control device, and further concentrated. After the preliminary enrichment is completed, the first activated carbon low temperature cold trap is heated, and the helium carrier gas device passes through the helium The gas carries the krypton and other gases in the first activated carbon low temperature cold trap into the first chromatography of the gas chromatography device. When the krypton gas is out of the peak, it is returned to the second activated carbon low temperature cold trap for the second chromatography, and the krypton gas is removed by inhalation. After purification, the gas device is sent to the collection container, and the collection container is transferred to the ATTA measurement system to measure the sample 85 Kr content, realized in air 85 Continuous separation and extraction of Kr gas and automatic continuous measurement of content.

Description

technical field [0001] The present invention relates to air 85 The technical field of Kr content monitoring, in particular to a kind of air 85 Automatic continuous measurement system for Kr gas separation, extraction and content. Background technique [0002] radioisotopes in the atmosphere 85 The release of Kr mainly comes from the cutting and dissolving processes of spent fuel rods after reprocessing in nuclear fuel plants. in the atmosphere 85 The monitoring of Kr content is of great significance in environmental protection. [0003] 85 The isotopic abundance of Kr is extremely low and cannot be detected by conventional mass spectrometry. Currently commonly used 85 Kr has γ-spectrum measurement, β-spectrum measurement. [0004] Gamma spectrum measurement is simple and fast, but limited by the device background and low detection efficiency, the detection limit is as high as 34000Bq / m 3 , much higher than in the air 85 Abundance of Kr. [0005] Beta spectrum meas...

AI Technical Summary

Problems solved by technology

The detection limit of LLC and LSC is low, but limited by half-life and radiation background, a large amount of sample is required (10 ~ 20m 3 ) and the measurement time is relatively long (a few days to a week), and it has high requirements on the ambient radiation background and gas purity

[0006] Due to the impossibility of continuous air 85 Kr gas separation and extraction, the current measurement methods have not shown quasi-continuous monitoring of air 85 The possibility of Kr content greatly limits the 85 Application of Kr in Environmental Monitoring

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