摘要
2020年6月22日,位于瑞典的全面禁止核试验条约国际监测系统放射性核素台站监测到大气中微量的134Cs,137Cs和103Ru等放射性核素,芬兰和爱沙尼亚在6月14至22日期间还监测到141Ce,95Zr和95Nb等放射性核素,国际上对这些核素的来源进行了各种猜测.本文在确证这些核素及其活度浓度基础上,结合国际监测系统放射性核素台站监测数据的统计分析,对核事件性质进行了判断,推算了放射性核素的释放时间,并利用大气输运模拟程序对这些放射性核素来源进行了初步判断.结果表明,134Cs与137Cs活度浓度比值约为1.1,可排除来自核试验或核爆炸;位于俄罗斯境内的RN61核素台站探测到131I和133I与位于挪威境内的RN49核素台站探测到的133Xe相关,可能来自反应堆运行过程中的泄漏;初步判断134Cs,137Cs和103Ru等核素可能来自北欧地区反应堆事故停堆换料或新鲜乏燃料转移过程中的意外释放;探测到的放射性核素活度浓度为μBq/m3量级,不会对公众健康产生影响.
On 22 June 2020, the trace amount of 134Cs, 137Cs and 103Ru in the atmosphere were detected by RN63 radionuclide station(in Sweden) of the International Monitoring System(IMS) for the Comprehensive NuclearTest-Ban Treaty(CTBT). Finland and Estonia declared the observation of these radionuclides and 141Ce, 95Zr and 95Nb respectively from 14 to 22 June 2020. Regarding the source term of the detection, various views all over the world were expressed on the networks. In this paper, these radionuclides and their activity concentrations are analyzed, and the nature of the detective event is determined through the analysis of these monitored data and the historical monitored data of each station. In addition, the release time of these radionuclide is estimated, and possible source term regions are obtained by using an atmospheric transport model. The results show that the activity ratio of 134Cs to 137Cs is about 1.10, which can exclude the possibility that the radionuclides detected come from nuclear test or nuclear explosion. The detection of 131I and 133I at the IMS RN61 station may be related to the small defection of reactor fuel assembly, and correlated temporally with the detection of 133Xe at the IMS RN49 station. Preliminary conclusions indicate that the 134Cs, 137Cs and 103Ru are likely to be related to the release of improper handling of reactor maintenance or fresh spent fuel transfer in Northern Europe region. Furthermore, due to the activity concentration is only μBq/m3 order of these radionuclides, it has no effect on public health.
作者
王世联
李奇
赵允刚
张新军
樊元庆
王晓明
贾怀茂
陈占营
刘蜀疆
常印忠
石建芳
Wang Shi-Lian;Li Qi;Zhao Yun-Gang;Zhang Xin-Jun;Fan Yuan-Qing;Wang Xiao-Ming;Jia Huai-Mao;Chen Zhan-Ying;Liu Shu-Jiang;Chang Yin-Zhong;Shi Jian-Fang(CTBT Beijing National Data Centre and Beijing Radionuclide Laboratory,Beijing 100085,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2020年第21期17-24,共8页
Acta Physica Sinica
