所属领域：
钍基熔盐堆核能系统
资源类型：
数理科学和化学
/ 物理学
/ 原子核物理学、高能物理学
/ 原子核物理学
文献作者：
DANTAS, BM; LOURENCO, MC; LIPSZTEIN, JL
文献发表年份：
1994
文献期刊：
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY-ARTICLES
文献摘要：Thoron (Rn-220) is a gaseous decay product of Th-232 decay chain which becomes a potential source of internal contamination for individuals who handle significant amounts of ores and raw materials containing thorium. With the objective of establishing an occupational control of such workers, a methodology which permits, by means of in-vivo measurements, the determination of the level of internally deposited Rn-220 daughters (Pb-212, Bi-212, and Tl-208), was developed at the Institute of Radiation Protection and Dosimetry/Brazilian Nuclear Energy Commission (IRD/CNEN) whole body counter. Previous calibration of an 8'' x 4'' NaI(Tl) detector was carried out using the Lawrence Livermore National Laboratory (LLNL) thorax phantom with the lung cavity filled with plastic bags containing Th-228 standard solution. After sealing, the bags are stored until radioactive equilibrium is reached. Patients are measured for 1 h in two steps, at an interval of approximately 20 h, positioning the detector over the thorax. A comparison of the activities determined at each measurement allows the discrimination of the contribution of the internally deposited short- and long-lived radionuclides. This technique was recently applied to a group of workers at a gas mantle industry in Rio de Janeiro. Results of these measurements will be shown.
文献类型： Article; Proceedings Paper
文献语种： English