某厂锆英砂生产氧氯化锆过程中放射性核素的转移和辐射防护

Radionuclide transport and radiation protection in production process of ZrOCl_2 from zircon sand in a factory

通过对某厂利用锆英砂生产氧氯化锆过程中原料、成品、中间产品及废弃物中天然放射性核素进行分析,探讨生产过程中放射性核素的转移和辐射防护。分析结果表明,原料中铀、钍、镭等天然放射性核素大部分转移到三次废酸中,废酸中铀、钍、镭-226含量分别为1.52 g/L、1.31 g/L、801 Bq/L,最终86%的U、99%的Th进入废水处理后的污泥中,14%的U进入处理后的废水中。氧氯化锆生产所产生的污泥需要按照放射性废物管理。氧氯化锆成品中天然放射性核素含量甚微,可以忽略。对工作人员附加外照射剂量进行了估算,得出工作人员最大附加外照射剂量为1.61 m Sv/a,并提出了相应的辐射防护建议。

Radionuclide transport and radiation protection are discussed based on analysis of some natural radionuclides in feedstocks, products, intermediates, and wastes in the production process of zirconium oxychloride（ ZrOCl2） from zircon sand in a factory. The results showed that U,Th,and -（226） Ra were enriched in the third waste acid with concentrations of 1. 52 g/L,1. 31 g/L,and 801 Bq/L,respectively. 86% of U and 99% of Th went into final residues of waste water treatment,14% of U was discharged into treated waste water.Natural radionuclides in ZrOCl2 are too little and no attention is needed. The residues from the ZrOCl2 production process need to be treated as radioactive wastes. The additional external irradiation doses of workers are calculated as a maximum of 1. 61 mSv/a. The relavant measures for radiation protection are suggested.