Abstract:

Objective To optimize the measurement method of total α and total β radioactivity levels in water，evaluate the uncertainty of the measurement method，and analyze the measurement results of total α and total β radioactivity in water in Xiushan County of Chongqing City in 2024. Methods The entire process of total α and total β radioactivity measurement in water was analyzed to determine the source and magnitude of uncertainty. The measurement results of total α and total β radioactivity in water from Xiushan County of Chongqing City in 2024 were analyzed. Results The lower limit of detection were 0.014 Bq/L for total α and 0.011 Bq/L for total β，with relative standard deviations of 7.29% and 6.88%，and average recoveries were 68.78% and 94.95%，respectively. The total α radioactivity concentration in drinking water in Xiushan County was L_Dα-0.15 Bq/L. There was a statistically significant difference between hot spring water and the other three types of water（F=41.060，P<0.05），while there was no statistically significant difference between the other three types of water（F=2.302，P>0.05）. The total β radioactivity concentration was 0.02-0.14 Bq/L. There was a statistically significant difference between hot spring water，tap water and mountain spring water（F=17.109，P<0.05），while there was a statistically significant difference between deep well water and tap water or mountain spring water（F=9.585，P<0.05）. Conclusion This method is simple to operate，and its precision，sensitivity，and accuracy meet the requirements for measuring the total α and total β radioactivity activity concentrations in water. It is suitable for measuring the total α and total β radioactive activity concentrations in water. The uncertainty mainly comes from sample net counting rate，counting efficiency，recovery rate and repeatability. In 2024，the total α and total β radioactivity levels in water in Xiushan County were both lower than the guidline values recommended by the national standards for drinking water.

Key words: Total α radioactivity, Total β radioactivity, Uncertainty evaluation, Test and analysis