采用溶液法-X射线荧光光谱研究了铀含量定量分析条件,为核临界安全在线监测提供了及时、可靠的数据,保障了燃料元件的安全生产.铀含量定量分析的最佳管流为40 m A、管压为40 k V;获得了铀的最佳测量角度为26.1196°,P H D范围为20~70.研究发现,分析过程中因溶液自身的重力,导致液体样杯中溶液底面出现曲面,进而使X射线的作用范围变化,使得部分射线无法进入探测器,计数下降,综合测量下限和计数率变化情况,确定溶液保持时间需小于730 s,铀溶液的取样量为5 m L.对6个监测点位管道处取得的待测溶液进行测定,铀测定值结果的相对标准偏差(RSD,n=6)均不大于1.2%,并与硫酸亚铁氧化-重铬酸钾还原滴定法的结果一致.%The quantitative analysis conditions of uranium content were investigated by X-ray fluorescence spectrometry combined with solution method ,which provided timely and reliable data for the on-line moni-toring of nuclear critical safety and guaranteed the safe production of fuel elements .The optimal current and voltage for the quantitative analysis of uranium content was 40 mA and 40 kV ,respectively .The opti-mal measuring angle was 26 .1196° ,and the PHD range was 20-70 .The results indicated that the gravity of solution led to hook face at bottom of solution in liquid sample cup ,which could cause the change of ac-tion scope of X-ray .As a result ,some X-rays could not enter into the detector ,leading to the decrease of counting .By comprehensive consideration of low limit of determination and the change of counting rate , the holding time of solution should be less than 730 s ,and the sampling amount of uranium solution was 5 mL .The solution samples from six different monitoring sites were determined .The relative standard devi-ations (RSD ,n=6) were all not more than 1 .2% .The determination results of uranium content were con-sistent with those obtained by ferrous sulfate oxidization-potassium dichromate reduction titration method .
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