An Efficient Radiochemical Method for Extraction of ۲۲۶Ra From the Soil Samples

Background: Radium-۲۲۶ is a radioactive element, with a very long half-life of ۱۶۰۰ years, producing radon gas. According to the United States Environmental Protection Agency, radon gas is the second most important factor causing lung cancer. Objectives: The purpose of this study was to separate ۲۲۶Ra from the soil of high background radiation area by a radiochemical method for using in radon calibration chamber. Methods: ۲۲۶Ra can be used in standard calibration chambers for calibration of radon detection systems. For this purpose, radiochemical method was used to extract radium from the soil with a high concentration of ۲۲۶Ra. Four soil samples used in this study were selected from high background radiation areas of Ramsar, north of Iran. Equal amounts of samples were gathered from each region and ground. The specific activity of radium-۲۲۶ was measured with HPGe detector. The highest specific activity of radium-۲۲۶ (۴۴.۸ Bq/g) belonged to Talesh-Mahaleh. After radiochemical separation of ۲۲۶Ra, the specific activity of extracted radium crystals was measured with the HPGe detector. Results: According to the results, the specific activity of ۲۲۶Ra was found to be ۹۴.۹۷ Bq/g. Therefore, the specific activity of ۲۲۶Ra was ۲.۱۲ times greater in the extracted crystals than in the original soil samples. Conclusion: The results indicate that using the radiochemical method proposed in this study, ۲۲۶Ra can be extracted with an efficiency of ۴۲%