摘要
Abstract
In order to accurately measure 232Th in the waste residues of associated radioactive mines,especially for the measurement of slag samples under non-equilibrium conditions,and to provide data support for radiation environment supervision,a method for measuring 232Th in slag using a high-purity germanium γ spectrometer was established.The method involves indirect measurement by selecting the characteristic γ rays of the daughter nuclides in the decay chain of 232Th,and calculating its specific activity by the relative comparison method.The slag samples in a non-equilibrium state are sealed for 20 days to enable 228Ra and 228Ac to reach equilibrium,and 228Th,224Ra and subsequent daughter nuclides to reach equilibrium.Then,the specific activity of the parent nuclide 232Th is obtained through conversion relationships.This method is accurate and efficient,with a detection limit of 1.1 Bq・kg-1,a precision better than 5%,and a relative error lower than 5%.The method of measuring 232Th in slag using a high-purity germanium γ spectrometer does not require complex chemical treatment,which makes up for the deficiencies of inductively coupled plasma mass spectrometry.The calculation method under non-equilibrium conditions is also more reliable than using the average value of a single characteristic peak or multiple characteristic peaks.关键词
高纯锗/矿渣/232Th/伴生放射性/放射性平衡/环境/固体废物Key words
high-purity germanium/slag/232Th/associated radioactivity/radioactive equilibrium/environment/solid waste分类
能源科技
