铀浓缩厂放射性废物管理与最小化实践
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摘要
介绍了某铀浓缩厂含铀放射性废物管理现状及放射性废物最小化方面的应用实践。放射性废物分类收集,集中处置,减少放射性废物的体积及产生量是基本要求。采用5%的Na_2CO_3和30%H_2O_2混合液以及清水对放射性污染管道、阀门等进行清洗,使α表面污染≤0.4 Bq/cm~2,清洗液厂内循环利用。通过除锈清洗液再利用、水压试验水再利用及容器清洗工艺优化改进等措施,单台容器平均废液产生量减少35%左右,从源头上控制了含铀废液的产生量。小容器处理工艺由湿法改为干法,废水产生量减少了90%;大容器清洗过程中,除锈液可重复利用5次,可使得除锈废液的产生量减少80%左右。提高吸附尾液循环利用比,减少了废水的产生量。采用钙盐联合沉淀法处理废水,废渣年产生量平均减少20%,废水处理合格率大大提高。在此基础上,介绍了实现含铀放射性废物最小化的几点思路,并提出相关措施。
The management status and minimization practice of radioactive wastes containing uranium in a uranium enrichment plant are introduced. Categorized collection, centralized disposal, and reduction of volume and amount of radioactive wastes are their basic requirements. Radioactive contaminated pipes and valves were cleaned with a mixed solution of 5% Na_2CO_3, 30% H_2O_2, and fresh water and reused in this plant to ensure that α surface contamination levels are less than 0.4 Bq/cm~2. By means of reutilization of rust removal solution and pressure test water and optimization of container cleaning process, the average amount of liquid waste produced by a single vessel was reduced by about 35%, these measures minimized the produced amount of liquid wastes containing uranium from origins. By changing the treatment process of small containers from wet process to dry process, the amount of produced waste water was reduced by 90%. The liquid waste produced from rust removal solution was also reduced by about 80% when it was reused for 5 times in a large container cleaning process. Increasing recycle ratio of adsorption tail liquid can reduce discharge amount of wastewater. Their wastewater treatment process was improved by adopting a calcium salt combined precipitation method. The average annual amount of dreg precipitate was reduced by 20%. The qualified rate of wastewater treatment was greatly improved. Some advices and measures are provided.
The management status and minimization practice of radioactive wastes containing uranium in a uranium enrichment plant are introduced. Categorized collection, centralized disposal, and reduction of volume and amount of radioactive wastes are their basic requirements. Radioactive contaminated pipes and valves were cleaned with a mixed solution of 5% Na_2CO_3, 30% H_2O_2, and fresh water and reused in this plant to ensure that α surface contamination levels are less than 0.4 Bq/cm~2. By means of reutilization of rust removal solution and pressure test water and optimization of container cleaning process, the average amount of liquid waste produced by a single vessel was reduced by about 35%, these measures minimized the produced amount of liquid wastes containing uranium from origins. By changing the treatment process of small containers from wet process to dry process, the amount of produced waste water was reduced by 90%. The liquid waste produced from rust removal solution was also reduced by about 80% when it was reused for 5 times in a large container cleaning process. Increasing recycle ratio of adsorption tail liquid can reduce discharge amount of wastewater. Their wastewater treatment process was improved by adopting a calcium salt combined precipitation method. The average annual amount of dreg precipitate was reduced by 20%. The qualified rate of wastewater treatment was greatly improved. Some advices and measures are provided.
引文
[1] IAEA. Minimization of radioactive waste from nuclear power plants and the back end of the nuclear fuel cycle[R]. Vienna: International atomic Energy Agency, 1995: 69-70.
[2] Eichholz, Geoffrey G. Radiation protection and radioactive waste management in the operation of nuclear power plants[J]. Health Physics, 2004, 87(6): 673-673.
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[4] 张学礼, 徐乐昌, 魏广芝, 等. 铀矿冶放射性固体废物最小化[J]. 铀矿冶, 2010, 29(4): 204-209. ZHANG Xueli, XU Lechang, WEI Guangzhi, etc. Uranium mining and metallurgical radioactive solid waste minimization[J]. Uranium Mining, 2010, 29(4): 204-209.
[5] 刘铁军, 孙学强. 田湾核电基地废物最小化[J]. 辐射防护, 2018, 38(1): 58-64.LIU Tiejun, SUN Xueqiang. Tian Wan nuclear power base waste minimization[J] . Radiation Protection, 2018, 38(1) : 58-64.
[6] 孙莹莹, 贺欢, 高彦锋, 等. 核环保工程放射性作业辐射防护管理体系构建与优化[J].辐射防护,2017, 37(5): 425-430.SUN Yingying, HE Huan, GAO Yanfeng, et al. Construction and optimization of radiation protection management system for radioactive operations in nuclear environmental protection engineering[J]. Radiation Protection, 2017, 37(5): 425-430.
[7] 核工业标准化研究所. 电离辐射与辐射源安全基本标准:GB 18871—2001[S]. 北京:中国标准出版社, 2002.
[2] Eichholz, Geoffrey G. Radiation protection and radioactive waste management in the operation of nuclear power plants[J]. Health Physics, 2004, 87(6): 673-673.
[3] García J M. Consideration of external events in the design of nuclear facilities other than nuclear power plants, with emphasis on earthquakes[R]. Vienna: International atomic Energy Agency, 2003: 1 011-4 289.
[4] 张学礼, 徐乐昌, 魏广芝, 等. 铀矿冶放射性固体废物最小化[J]. 铀矿冶, 2010, 29(4): 204-209. ZHANG Xueli, XU Lechang, WEI Guangzhi, etc. Uranium mining and metallurgical radioactive solid waste minimization[J]. Uranium Mining, 2010, 29(4): 204-209.
[5] 刘铁军, 孙学强. 田湾核电基地废物最小化[J]. 辐射防护, 2018, 38(1): 58-64.LIU Tiejun, SUN Xueqiang. Tian Wan nuclear power base waste minimization[J] . Radiation Protection, 2018, 38(1) : 58-64.
[6] 孙莹莹, 贺欢, 高彦锋, 等. 核环保工程放射性作业辐射防护管理体系构建与优化[J].辐射防护,2017, 37(5): 425-430.SUN Yingying, HE Huan, GAO Yanfeng, et al. Construction and optimization of radiation protection management system for radioactive operations in nuclear environmental protection engineering[J]. Radiation Protection, 2017, 37(5): 425-430.
[7] 核工业标准化研究所. 电离辐射与辐射源安全基本标准:GB 18871—2001[S]. 北京:中国标准出版社, 2002.