The investigation of ²³⁹⁺²⁴⁰Pu, ⁹⁰Sr and ¹³⁷Cs background radiation levels in soil samples in some provinces in the north of Vietnam

This study was carried out to investigate background levels of plutonium (239+240Pu), strontium (90Sr), and cesium (137Cs) in the soil in some provinces in northern Vietnam. Thirty-one soil samples were collected from October 2020 to January 2022. These samples were analyzed by gamma spectrometry, alpha spectrometry, beta counting, and radiochemical separation procedures to quantify 137Cs, 239+240Pu, and 90Sr radioactivities. The concentrations (Bq/kg dry weight) have been observed in the range of 0.768 – 2.129 for 137Cs, 0.018 – 0.058 for 239+240Pu, and 0.022 – 0.697 for 90Sr, their average values are 1.393 ± 0.196, 0.039 ± 0.014 and 0.129 ± 0.011, respectively, which are relatively lower than the reported values in the neighboring country. The average recovery for radiochemical separation for 239+240Pu and 90Sr was 67.9 % and 60.2 %, respectively, the minimum detectable activity (MDA) (Bq/kg) for 137Cs, 239+240Pu, and 90Sr are 0.012, 0.004, 0.1, respectively.