Sampling-type radiation monitoring device for high-humidity gases

Abstract

The invention relates to the technical field of nuclear radiation detection, and provides a sampling-type radiation monitoring device suitable for radioactivity measurement of high-humidity gases. The sampling-type radiation monitoring device comprises a radiation measuring instrument and a gas sampling loop. Two redundant dehumidifiers are arranged on the gas sampling loop and are redundant to each other. Each dehumidifier is connected with four electromagnetic valves and is switched by the electromagnetic valves. Through opening and closing of the electromagnetic valves, one dehumidifier is positioned on a front gas circuit of the radiation measuring instrument, and the other humidifier is positioned on a rear gas circuit of the radiation measuring instrument. An electric heat tracing device used for heating sample gases in pipelines is arranged in front of a gas inlet of the radiation measuring instrument. The electromagnetic valves and the electric heat tracing device are connected with a temperature and humidity control cabinet. The sampling-type radiation monitoring device can effectively measure radiation of the high-humidity gases without reduction of sensitivity, runs without local discharge of radioactive condensate water, and is stable, reliable and convenient to operate and maintain.

Description

technical field [0001] The invention relates to the technical field of nuclear radiation detection, in particular to a sampling radiation monitoring device suitable for high-humidity gas radioactivity measurement. Background technique [0002] The gas sampling radiation monitoring device is a very widely used type of radiation detector. The basic principle is to use an air pump or a fan to draw the gas to be tested in a harsh environment or inaccessible areas to a designated area through the sampling pipeline, so that in a mild environment In the process, a special radiation detector is used to measure the content of radioactive substances in the sampled gas, and to monitor whether radioactive contamination occurs in the area to be tested, so as to determine whether the nuclear process (including radiation) related to the sampling area is abnormal and whether the staff may be injured by radiation. . Since the method of gas sampling and measurement ensures that the area whe...

AI Technical Summary

Problems solved by technology

But one problem with this detector is that it uses the sampling gas as the working gas inside, and at the same time uses the insulator exposed in the sampling gas to isolate the high voltage level, so the detector is easily disturbed by the humidity of the sampling gas. When the humidity of the sampling gas is too high (such as greater than 80%), the sampling gas contains a large number of water molecules, which will greatly reduce the insulation of the gas-flow ionization chamber, increase the leakage current, increase the noise rapidly, seriously reduce the sensitivity of the equipment, and greatly distort the measurement results, even Cause serious over-threshold measurement events, trigger false alarms, and bring huge problems to the normal operation and maintenance of equipment

In nuclear equipment such as nuclear power plants, the atmospheric humidity in many process plants is very high (such as pools or pit water in the room), and when the humidity of the external atmospheric environment increases (such as cloudy or rainy days), Air humidity in factory rooms that are atmospherically ventilated to the outside world can also increase significantly. When air is drawn from these rooms for measurement, the high humidity levels in the sampled gas can seriously interfere with the normal measurement of radioactive gases

[0004] When the commonly used dehumidification equipment is added in front of the radiation measuring instrument to dehumidify the sampled gas, radioactive condensed water will be generated. The radioactive condensed water cannot be discharged on the spot, and it needs to be manually connected or drained to the radioactive sewage tank by using a special pipeline. In the process, the complexity of the equipment and the difficulty of maintenance are seriously increased

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