放射性碘监测仪探测效率的准确度研究
|
摘要
放射性碘是核环境保护的重要监测内容。目前,碘监测仪均采用圆柱形活性炭取样盒,由均匀分布的标准体源进行效率标定,很难模拟实际测量中碘在活性炭盒中的分布情况,因此无法准确标定其探测效率。为了检验碘监测仪探测效率的准确性,利用蒙特卡罗软件MCNP(Monte Carlo N Particle Transport Code),模拟计算了EIM型碘监测仪对碘在活性炭取样盒内呈不同分布情况下的探测效率,并进行验证。同时建立的碘监测仪探测效率的蒙特卡罗模型,为改进仪器设计,提高探测效率的准确度提供参考。结果表明:对于与探测器同轴的井型活性炭采样盒,使用均匀分布体源标定碘监测仪的探测效率准确度较高。
[Background] The monitoring of radioactive iodine has been an important part of nuclear environmental protection. Detection efficiency is the main indicator for calibrating and evaluating iodine monitor.[Purpose] Due to the environment and the form of radioactive iodine, the distribution of iodine in the activated carbon sampling box is not uniform. At present, when the detection efficiency of the iodine monitor is calibrated, the activity of the standard volumetric source used is uniform, which is different from the actual distribution. So it is necessary to verify the accuracy of detection efficiency of the environmental iodine continuous monitor.[Methods] The detection efficiency of iodine in different positions was simulated in the activated carbon sampling box using the Monte Carlo software MCNP, and the results was verified by experiments.[Results] The Monte Carlo model of detection efficiency of the iodine monitor was established, and it provided reference for improving the design of the iodine monitor and the accuracy of detection efficiency.[Conclusions] The results show that the detection efficiency of the iodine monitor is accurate calibrated with133 Ba uniform source and can accurately reflect the performance of the iodine monitor.
[Background] The monitoring of radioactive iodine has been an important part of nuclear environmental protection. Detection efficiency is the main indicator for calibrating and evaluating iodine monitor.[Purpose] Due to the environment and the form of radioactive iodine, the distribution of iodine in the activated carbon sampling box is not uniform. At present, when the detection efficiency of the iodine monitor is calibrated, the activity of the standard volumetric source used is uniform, which is different from the actual distribution. So it is necessary to verify the accuracy of detection efficiency of the environmental iodine continuous monitor.[Methods] The detection efficiency of iodine in different positions was simulated in the activated carbon sampling box using the Monte Carlo software MCNP, and the results was verified by experiments.[Results] The Monte Carlo model of detection efficiency of the iodine monitor was established, and it provided reference for improving the design of the iodine monitor and the accuracy of detection efficiency.[Conclusions] The results show that the detection efficiency of the iodine monitor is accurate calibrated with133 Ba uniform source and can accurately reflect the performance of the iodine monitor.
引文
1 NB/T 20374-2016:核电厂烟囱的气载放射性物质取样[S].北京:核工业标准化研究所,2016.NB/T20374-2016:Samplingairborne radioactive materials from the stacks of nuclear power plant[S].Beijing:Institute for Standardization of Nuclear Industry,2016.
2 GB/T 7165.4-2008:气态排出流(放射性)活度连续监测设备第4部分:放射性碘监测仪的特殊要求[S].北京:中国标准出版社,2008.GB/T 7165.4-2008:Equipment for continuousmonitoring of radioactivity in gaseous effluents Part 4:specific requirements for radioactive iodine monitors[S].Beijing Standards Press of China,2008.
3潘自强.电离辐射环境监测与评价[M].北京:原子能出版社,2007:200.PAN Ziqiang.Monitoring and evaluation of ionizing radiation environment[M].Beijing:Atomic Energy Press2007:200.
4哈继录,张超,甘霖.空气中131I的取样和测量方法的研究[J].辐射防护,1992,12(4):260?264.HA Jilu,ZHANG Chao,GAN Lin.A method for sampling and measuring131I air[J].Radiation Protection,1992,12(4):260?264.
5宋培峰,凌球,郭兰英.基于133Ba标准源刻度131I取样滤盒γ总探测效率的方法研究[J].核电子学与探测技术,2006,26(1):115?117.SONG Peifeng,LING Qiu,GUO Lanying.Calibrating theγdetecting efficiency of 131I charcoal cartridge sampler based on133Ba standard source[J].Nuclear Electronics&Detection Technology,2006,26(1):115?117.
6杜鸿善,李俊兰,颜素娟.模拟131I标准源的研制[J].同位素,1996,9(3):129?135.DU Hongshan,LI Junlan,YAN Sujuan.Development of simulated131I standard source[J].Journal of Isotopes,1996,9(3):129?135.
7周银行,林青川,郭洪波.基于点源133Ba刻度131I探测效率的面积加权法[J].核电子学与探测技术,2009,29(6):1353?1355.ZHOU Yinhang,LIN Qingchuan,GUO Hongbo.The calibration method of131I detection efficiency based on area weight for133Ba standard point source[J].Nuclear Electronics&Detection Technology,2009,29(6):1353?1355.
8周银行,马玉刚.MCNP能峰展宽的NaI探测效率研究[J].核电子学与探测技术,2007,27(6):1061?1063.ZHOU Yinhang,MA Yugang.MCNP peak broadening simulation of the detection efficiency of NaI[J].Nuclear Electronics&Detection Technology,2007,27(6):1061?1063.
9杨怀元,韩国胜.确定空气中放射性131I取样滤盒γ总探测效率的简单方法[J].辐射防护,1993,1(13):47?51.YANG Huaiyuan,HAN Guosheng.A simple method of determiningγdetection efficiency of charcoal cartridge sampler for131I in the air[J].Radiation Protection,1993,1(13):47?51.
10 GB/T14584-1993:空气中碘-131的取样与测定[S].国家环境保护局,1993.GB/T14584-1993:Sampling and determination of131I in air[S].National Environmental Protection Agency,1993.
11刘明健,郭庆元,张燕.空心圆柱体131I取样滤盒γ探测效率刻度法[J].核电子学与探测技术,2001,26(1):56?58.LIU Mingjian,GUO Qingyuan,ZHANG Yan.The method ofγdetecting efficiency for hollow cylinder used in131I sampling[J].Nuclear Electronics&Detection Technology,2001,26(1):56?58.
2 GB/T 7165.4-2008:气态排出流(放射性)活度连续监测设备第4部分:放射性碘监测仪的特殊要求[S].北京:中国标准出版社,2008.GB/T 7165.4-2008:Equipment for continuousmonitoring of radioactivity in gaseous effluents Part 4:specific requirements for radioactive iodine monitors[S].Beijing Standards Press of China,2008.
3潘自强.电离辐射环境监测与评价[M].北京:原子能出版社,2007:200.PAN Ziqiang.Monitoring and evaluation of ionizing radiation environment[M].Beijing:Atomic Energy Press2007:200.
4哈继录,张超,甘霖.空气中131I的取样和测量方法的研究[J].辐射防护,1992,12(4):260?264.HA Jilu,ZHANG Chao,GAN Lin.A method for sampling and measuring131I air[J].Radiation Protection,1992,12(4):260?264.
5宋培峰,凌球,郭兰英.基于133Ba标准源刻度131I取样滤盒γ总探测效率的方法研究[J].核电子学与探测技术,2006,26(1):115?117.SONG Peifeng,LING Qiu,GUO Lanying.Calibrating theγdetecting efficiency of 131I charcoal cartridge sampler based on133Ba standard source[J].Nuclear Electronics&Detection Technology,2006,26(1):115?117.
6杜鸿善,李俊兰,颜素娟.模拟131I标准源的研制[J].同位素,1996,9(3):129?135.DU Hongshan,LI Junlan,YAN Sujuan.Development of simulated131I standard source[J].Journal of Isotopes,1996,9(3):129?135.
7周银行,林青川,郭洪波.基于点源133Ba刻度131I探测效率的面积加权法[J].核电子学与探测技术,2009,29(6):1353?1355.ZHOU Yinhang,LIN Qingchuan,GUO Hongbo.The calibration method of131I detection efficiency based on area weight for133Ba standard point source[J].Nuclear Electronics&Detection Technology,2009,29(6):1353?1355.
8周银行,马玉刚.MCNP能峰展宽的NaI探测效率研究[J].核电子学与探测技术,2007,27(6):1061?1063.ZHOU Yinhang,MA Yugang.MCNP peak broadening simulation of the detection efficiency of NaI[J].Nuclear Electronics&Detection Technology,2007,27(6):1061?1063.
9杨怀元,韩国胜.确定空气中放射性131I取样滤盒γ总探测效率的简单方法[J].辐射防护,1993,1(13):47?51.YANG Huaiyuan,HAN Guosheng.A simple method of determiningγdetection efficiency of charcoal cartridge sampler for131I in the air[J].Radiation Protection,1993,1(13):47?51.
10 GB/T14584-1993:空气中碘-131的取样与测定[S].国家环境保护局,1993.GB/T14584-1993:Sampling and determination of131I in air[S].National Environmental Protection Agency,1993.
11刘明健,郭庆元,张燕.空心圆柱体131I取样滤盒γ探测效率刻度法[J].核电子学与探测技术,2001,26(1):56?58.LIU Mingjian,GUO Qingyuan,ZHANG Yan.The method ofγdetecting efficiency for hollow cylinder used in131I sampling[J].Nuclear Electronics&Detection Technology,2001,26(1):56?58.