Influence of high radon background on the response of alpha radioactive aerosol monitor

Abstract

Backgroundα radioactive aerosol monitors are widely used for radiation safety protection in nuclear facilities, uranium mining and metallurgy, nuclear fuel processing, nuclear power plants, nuclear medicine, etc. High radon background will interfere with the accuracy of monitoring results.PurposeThis study aims to ensure the accuracy of its monitoring results by test its response and anti-radon interference performance.MethodsA certain type of alpha radioactive aerosol monitor was taken as the experimental object. 239Pu filter membrane reference sources were prepared as the measurement standard, and the standard radon chamber was used to provide different radon backgrounds and test the surface emissivity response, nonlinearity and judgment limit (95% confidence level).ResultsFirst, under the influence of high radon background, the response of surface emissivity is larger than that under normal background condition. In the same measurement period, the surface emissivity response in the continuous measurement mode is greater than that in the accurate mode, and the measurement accuracy in the accurate mode is higher than that of continuous mode. Second, when the surface emissivity of the 239Pu filter membrane is greater than 104 min-1·2πSr, the influence of high radon background is reduced, and the deviation of the surface emissivity response is less than 5.3% (only 2.9% in the accurate mode). Third, the duration of single measurement should be more than 60 min to ensure the reliability of monitoring results whilst the continuous sampling and measurement time should be longer than 24 h if there is a high radon background.ConclusionsThe research method has important reference value for the measurement, production and algorithm improvement of the α-radioactive aerosol monitor.

Keywords

• high radon background
• alpha radioactive aerosol monitor
• performance
• influence