A Method to Measure Radon Concentration in Ground Water by Using Standard γ-ray Volume Source

Abstract

The detection efficiency to obtain radon concentration in ground water by γ-ray spectrometry was determined using a standard volume source in stead of previous ²²⁶Ra standard source. Radon concentration of ground water in a 100mL Teflon vial was determined from the γ-ray measurement of the 352keV γ ray emitted from ²¹⁴Pb on the assumption that radon and its progenies were in a radioactive equilibrium in a closed vial. The 352keV γ-ray counting efficiency for a 100mL Teflon vial was determined based on the detection efficiency of Ge detector from a standard volume source in a U8 container. The detection limit in this method was 8Bq/L. The radon concentrations in ground water from 6 locations were agreed well with previous method.