摘要
本研究联合三重四极杆电感耦合等离子体质谱(ICP-QQQ-MS)和多接收电感耦合等离子体质谱(MC-ICP-MS),快速准确地测量浓缩铀材料中铀同位素丰度比值、^(230)Th/^(234)U和^(231)Pa/^(235)U原子物质的量比值,并诊断铀年龄。结果表明,Neptune XT型MC-ICP-MS和Agilent 8800型ICP-QQQ-MS对^(233)U丰度的有效检测限分别为3×10^(-9)和6×10^(-10),适用于^(233)U丰度高于6×10^(-8)和样品量充足的样品,对10^(-7)量级^(233)U/^(235)U同位素丰度比的测量精密度达到1.0%(2σ)和4.8%(2σ)。采用GBW04240作为外标校正质量分馏效应,建立了基于ICP-QQQ-MS的10-5量级原子物质的量比值的230Th/234U和10-8量级原子物质的量比值的231Pa/^(235)U的同时测量方法,对230Th-234U和231Pa-^(235)U模式年龄的检测限分别达到0.2 a和0.5 a,定年不确定度为0.65 a(2σ)和0.67 a(2σ)。结合MC-ICP-MS测量的234U/^(235)U、^(235)U/238U和236U/^(235)U等同位素丰度比值,判断某批次浓缩铀样品可能用于实验堆,最后一次分离纯化时间在2009年左右,且均已经历反应堆辐照。该技术将铀年龄诊断由经典系统分离定量方法的1个月左右缩短至1周以内,分析速度快、结果准确,可为核取证、核标准物质研制定值和核保障监督等提供技术支持。
The characteristics of enriched uranium materials are very important for nuclear fuel cycle and nuclear forensic analysis.Among all those fingerprints,the uranium isotope ratios and the uranium age are considered to be of major parameters for tracing the sources and process conditions.To the best of our knowledge,there are only a few relevant articles focusing on the analysis of^(233)U isotope abundance.In most of the published literatures subjected to uranium age dating,either^(230)Th-^(234)U chronometer or ^(231)Pa-^(235)U chronometer was employed to determine the age of enriched uranium materials with the isotope dilution mass spectrometry and anion exchange separation procedure,where the most time-consuming step was the sample preparation.Hence,this project aimed to develop a fast and flexible method for the determination of the uranium isotope ratios,^(230)Th/^(234)U and ^(231)Pa/^(235)U atom ratios of the enriched uranium samples by the combination of multiple collector inductively coupled plasma mass spectrometry(MC-ICP-MS)and triple quadrupole inductively coupled plasma mass spectrometry(ICP-QQQ-MS).The results showed that the limits of detection(LODs)of^(233)U by Neptune XT MC-ICP-MS and Agilent 8800 ICP-QQQ-MS were 3×10^(-9)and 6×10^(-10),respectively,and the relative standard deviations(RSDs)of^(233)U/^(235)U isotope ratios at the level of 10^(-7)by MC-ICP-MS and ICP-QQQ-MS were 1.0%(2σ)and 4.8%(2σ),respectively.The standard sample bracketing(SSB)method of ICP-QQQ-MS based on the calibration of GBW04240 reference material was established to correct the mass fractionation of ^(230)Th/^(234)U and ^(231)Pa/^(235)U atom ratios simultaneously.The ages of the uranium materials were diagnosed by the two parent-daughter relations of 234 U-230 Th and^(235)U-^(231)Pa,indicating that the LODs of age dating were 0.2 a and 0.5 a,respectively.Meanwhile,the isotope ratios of ^(234)U/^(235)U,^(235)U/^(238)U and ^(236)U/^(235)U were determined by MC-ICP-MS.The fingerprints showed that the last purification time of
作者
汪伟
徐江
席瑞阳
王亚龙
郭思琪
方随
李志明
林剑锋
张海涛
张小林
王春杰
何亚姣
WANG Wei;XU Jiang;XI Rui-yang;WANG Ya-long;GUO Si-qi;FANG Sui;LI Zhi-ming;LIN Jian-feng;ZHANG Hai-tao;ZHANG Xiao-lin;WANG Chun-jie;HE Ya-jiao(Northwest Institute of Nuclear Technology,Xi’an 710024,China)
出处
《质谱学报》
EI
CAS
CSCD
北大核心
2023年第6期797-806,I0003,共11页
Journal of Chinese Mass Spectrometry Society
基金
国家重点研发计划(2021YFF0700100)。
