同位素稀释伽马能谱法测量Pu浓度研究  

Research on Isotope Dilution Gamma Spectroscopy for Determining Plutonium Concentration

作　　者：王妍[1] 刘宏斌[1] 何丽霞[1] 许小明[1] WANG Yan;LIU Hongbin;HE Lixia;XU Xiaoming(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《原子能科学技术》2023年第11期2225-2232,共8页Atomic Energy Science and Technology

摘　　要：对Pu浓度测量的同位素稀释伽马能谱法(IDGS)进行初步验证。采用高239 Pu丰度Pu溶液作为同位素稀释剂,利用Pu工作样品在添加稀释剂前后241 Pu和239 Pu等同位素丰度的变化,结合高纯锗伽马能谱测量手段,研究并建立了IDGS技术测定Pu浓度和同位素组成的方法。实验中,利用控制电位库仑法和质谱法精确标定了Pu稀释剂工作标准和Pu工作样品的浓度及其同位素组成。结果表明:在1.5 h内,IDGS技术对Pu浓度测量结果的相对标准偏差(RSD)≤0.68%,其测量值与库仑法测量结果的一致性良好,相对偏差在0.3%~2.3%之间;对同一待测Pu样品的2组平行取样测量结果RSD≤0.98%;在1∶4~4∶1的最佳稀释比范围内,较少的稀释剂用量便可达到与库仑法测量结果较好的一致性。表明改进后的IDGS技术测定Pu浓度的方法可行,未来可用于乏燃料溶液中Pu浓度的快速测量,为我国后处理厂核材料管理提供技术支持。Preliminary validation of isotope dilution gamma spectroscopy(IDGS)for plutonium concentration measurement was investigated in this study.A high 239 Pu abundance plutonium solution was used as an isotope dilution agent.By studying the changes in isotopic abundance of 241 Pu and 239 Pu before and after adding the dilution agent to plutonium working sample,and combining it with high-purity germanium gamma spectrometry,a method for measuring plutonium concentration and isotopic composition using IDGS technology was established.In this experiment,the concentration and isotopic composition of the plutonium diluent working standard and the plutonium working sample were accurately calibrated by the controlled potential coulometry and mass spectrometry separately.Different gamma ray pairs with similar energy from appropriate energy regions were selected to calculate the isotopic abundance ratio,and the efficiency calibration was performed on this gamma ray pairs.The optimal volume and concentration of the plutonium gamma measurement standard solution were explored and determined.Using IDGS technology,the test samples with plutonium concentration of 2 g/L in the nitric acid plutonium solution and the abundance range of 239 Pu from 57%to 70%were measured.The results show that within 1.5 h,the RSD of IDGS technology for plutonium concentration measurement is≤0.68%,and the measured values are in good agreement with those measured by the Coulomb method,with deviations from 0.3%to 2.3%.When measuring the isotopic composition,the RSD of 241 Pu/239 Pu is≤0.46%,and the RSD of 239 Pu abundance is≤0.66%.The RSD of the measurement results for two parallel samples of the same plutonium sample is≤0.98%.With the optima dilution ratio range of 1∶4 to 4∶1,a small amount of dilution agent could achieve good consistency with the Coulomb method measurement results,but beyond this dilution ratio range,the deviation of the measurement results from the Coulomb method is larger.These results indicate that using domestically high-qua

关 键 词：PU 同位素稀释 伽马能谱法 

分 类 号：TL24[核科学技术—核燃料循环与材料]