Method for measuring mechanical leakage rate of activated carbon bed through gas chromatography

Abstract

The invention relates to a method for measuring the mechanical leakage rate of an activated carbon bed through gas chromatography, and the method comprises the steps: injecting stable organic volatilegas into an activated carbon bed detection system, enabling the stable organic volatile gas to flow through the activated carbon bed, carrying out the gas sampling at the upstream and downstream of the activated carbon bed, measuring the relative integral area of the upstream and downstream samples through a chromatographic instrument via the gas chromatography, obtaining the sample gas concentration through the loading of a standard curve, and calculating the mechanical leakage rate of the activated carbon bed according to a leakage rate formula. The method is safe and reliable, is simple inoperation, is good in repeatability, is high in measurement precision, is good in on-site adaptability, and can be used for the evaluation test of the leakage rate of an iodine absorber carbon bed ofa nuclear air purifying system.

Description

technical field [0001] The invention belongs to the leakage rate detection technology of activated carbon beds in the field of nuclear industry, and in particular relates to a method for measuring the mechanical leakage rate of activated carbon beds by using gas chromatography. Background technique [0002] In the reactor radioactive fission products of pressurized water reactor nuclear power plants, gaseous radioactive iodine is mainly presented as molecular iodine ( 129 I 2 , 131 I 2 ) and organic iodine (CH 3 131 I). Among them, elemental molecular iodine accounts for 90-95% of gaseous radioactive iodine, and organic iodine only accounts for 5-10% of gaseous radioactive iodine. Although the concentration of radioactive iodine is very low, after a design basis accident, radioactive iodine in the air in the reactor containment The concentration does not exceed 1Ci / m 3 or 8μg / m 3 , but because the human thyroid gland has a high ability to absorb radioactive iodine, i...

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Problems solved by technology

Among them, elemental molecular iodine accounts for 90-95% of gaseous radioactive iodine, and organic iodine only accounts for 5-10% of gaseous radioactive iodine. Although the concentration of radioactive iodine is very low, after a design basis accident, radioactive iodine in the air in the reactor containment The concentration does not exceed 1Ci / m 3 or 8μg / m 3 , but because the human thyroid gland has a high ability to absorb radioactive iodine, it is very harmful to human health after release. Therefore, it is necessary to use filters in the ventilation system of nuclear power plants for filtration to intercept the possible presence of radioactive iodine in the air. Radioactive substances, providing safe and harmless fresh air to the service area, so as to reduce and control the radiation impact of radioactive substances on workers and emergency personnel in accidents

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