Intercomparison of γ-spectrometry analysis of radionuclides between China and Japan in 2012-2013

Radioactivity and elemental oxidation composition in soil from Yangjiang, a high background natural radiation area, China

Soil is an important source and medium of radionuclides, and the content of radioactivity in soil is crucial for radiological impact evaluation. In this study, twenty soil samples in the high background natural radiation area of Yangjiang, China were collected and analyzed for 226Ra, 232Th, 40K and 137Cs concentrations in order to evaluate the radiological health risk in the area. Results showed that the average activity concentrations of 226Ra, 232Th and 40K are 66 Bq/kg, 109 Bq/kg and 211 Bq/kg, respectively. The calculated radiological parameters of radium equivalent activity (Raeq), absorbed dose rate (D), annual effective dose equivalent (AEDE), internal and external hazard indices (Hin and Hex) show a large variation at different sampling sites. Additionally, the elemental oxidation composition and 40K/K mass ratio in the soil were analyzed to further augment the background information of the high background radiation area in Yangjiang.

AN INTER-COMPARISON OF PASSIVE DOSEMETERS FOR TERRESTRIAL GAMMA RADIATION MEASUREMENTS

To evaluate the measurement method of passive dosemeters for terrestrial gamma radiation measurements. An inter-comparison of passive dosemeters for terrestrial gamma radiation measurements was organized alternately by the Japan Chemical Analysis Center, National Institute for Radiological Protection of Chinese Center for Disease Control and Prevention and Radiation Monitoring Technical Center of Ministry of Environmental Protection every 2 years. The procedures and exposure conditions of the field-exposure and reference irradiation test were provided by the organizer. During 2019-2020, the En values of Field-1 and Field-2 in three laboratories were lower than 1.0 and assigned 'acceptable' according to inter-comparison criteria. After the correction of the fading effect of dosemeter material, the En values of reference irradiation test (0.301 mGy, 1.000 mGy) in three laboratories were lower than 1.0 and assigned 'acceptable'.

Stack releases of radionuclides from an integrated steel plant in China

Crude steel production in China made up the majority of the global output, at 49.5% in 2014. High temperature smelting processes result in the release of natural radionuclides, including radon gas and other air pollutants into the atmosphere. This paper conducts an analysis of the raw materials, end products and flue gas sampled from an integrated steel plant from within China's Jiangxi Province, with annual production of 8.50 Mt of crude steel. Normalized stack emissions factors of radionuclides from steel production were first reported in China. The results showed that sintering was the main process that released natural radionuclides, and the main radionuclides released into the atmosphere were ²²²Rn (86.4 GBq/Mt), ²¹⁰Pb (13.4 GBq/Mt), and ²¹⁰Po (1.71 GBq/Mt). The results provided essential basic data for radiological impact assessment of steel production, as well as that of nuclear energy chain, coal chain and other electricity sources.