摘要
铀颗粒物中^(230)Th与^(234)U物质的量比值n(^(230)Th)/n(^(234)U)可用于诊断铀材料的生产年龄。转移并消解多个不同铀丰度的CRM124-4,GBW04234和GBW04238铀颗粒物制备最初溶液,分样后在各溶样瓶中分别加入定量的^(233)U稀释剂和^(229)Th稀释剂。其中,加入^(229)Th稀释剂的^(230)Th定量样品进一步分离纯化去铀,采用多接收电感耦合等离子体质谱仪(multiple colletor inductively coupled plasma mass spectrometry,MC-ICP-MS)分别测定n(^(238)U)/n(^(233)U)和n(^(230)Th)/n(^(229)Th),由同位素稀释质谱法得到最初溶液中^(238)U的质量分数w(^(238)U)和^(230)Th的质量分数w(^(230)Th)。待测铀颗粒物中n(^(238)U)/n(^(234)U)已知,计算出最初溶液中w(^(234)U)及n(^(230)Th)/n(^(234)U),最后诊断出颗粒物的生产年龄。研究结果表明:6.1×10^(-5)~3.8×10^(-4) g量级CRM124-4,GBW04234和GBW04238铀颗粒物中n(^(230)Th)/n(^(234)U)测量值的相对偏差分别为2.7%、6.1%和1.8%;CRM124-4,GBW04234和GBW04238所对应铀材料的生产年龄诊断结果分别为57.81±1.55 a,23.32±1.42 a和22.99±0.40 a(2σ),诊断精度达到国际同等先进水平。
The amount of substance ratio of^(230)Th to^(234)U in uranium particles can be used to diagnose the age of uranium particles.The n(^(238)U)/n(^(233)U)and n(^(230)Th)/n(^(229)Th)in CRM124-4,GBW04234,and GBW04^(238)Uranium particles with different uranium abundances are determined by multiple colletor inductively coupled plasma mass spectrometry(MC-ICP-MS).The age of uranium particles is diagnosed by isotope dilution mass spectrometry after uranium thorium separation and purification.The results show that the relative experimental standard uncertainty of the n(^(230)Th)/n(^(234)U)is 2.7%,6.1%,and 1.8%,respectively in CRM124-4,GBW04234,and GBW04238.Correspondingly,the diagnostic age of CRM124-4,GBW04234 and GBW04^(238)Uranium particles are(57.81±1.55)a,(23.32±1.42)a,and(22.99±0.40)a,respectively.This method can provide technical support for nuclear safeguards and nuclear forensics by determining the n(^(230)Th)/n(^(234)U)in a single uranium particle simulation sample at the level of 100 microns or sub milligram uranium materials,and diagnosing the age of uranium materials.
作者
汪伟
徐江
李志明
沈小攀
粟永阳
凡金龙
张海涛
王玉凤
方随
袁祥龙
邓虎
王文亮
WANG Wei;XU Jiang;LI Zhiming;SHEN Xiaopan;SU Yongyang;FAN Jinlong;ZHANG Haitao;WANG Yufeng;FANG Sui;YUAN Xianglong;DENG Hu;WANG Wenliang(Northwest Institute of Nuclear Technology,Xi’an 710024,China)
出处
《现代应用物理》
2022年第2期160-166,共7页
Modern Applied Physics
基金
国家重点研发计划资助项目(2021YFF0700100)。