气体采样滤膜中钚的激光诱导击穿光谱定量分析研究

在核设施排放物的监测中，为确保环境安全及实现核材料衡算，需针对通风管气体采样滤膜中钚的含量进行分析。为探索利用激光诱导击穿光谱（LIBS）技术定量分析滤膜中钚元素含量的可行性，开展了某核设施热室内含钚气体采样滤膜的LIBS分析研究。通过分析含钚气体采样滤膜中钚的LIBS特征光谱信号，筛选出钚的有效发射谱线，并优化LIBS测量延迟时间参数，最终得到了浓度范围较低情况下的定量标准曲线，并进行了技术验证分析。研究结果显示，针对滤膜中的钚元素可采用有效特征谱线进行LIBS定量分析，能用于定量分析钚的可分析有效特征谱线为PuⅡ 443.298 nm、PuⅠ 460.721 nm、PuⅡ 466.389 nm。分析结果表明，LIBS分析结果的精度好于3%。

Technology Research of Laser-induced Breakdown Spectroscopy for Quantitative Analysis of Plutonium in Gas Sampling Filter

The analysis and determination of nuclear material is an important part in nuclear safeguards. Laser-induced breakdown spectroscopy (LIBS) is a very promising technology in material determination. In nuclear facility effluent air monitoring, it is necessary to measure and analyze the content of plutonium in filters sampling from vent-pipes. In order to explore the application of LIBS technology for plutonium analysis in aerosol sampling filters, the measurement of the plutonium in the off-gas of the radioactive reprocessing plant was studied by using single pulse LIBS (SP-LIBS) technology for the reason of NMA (nuclear material account) of RPP (reactor power plant). To study the feasibility of membrane quantitative analysis of plutonium content, experiments were carried out on sampling filters. In this research, sampling filters were from a glovebox in a hot cell of a certain nuclear facility, as those samples were from different position of vent pipe, and the gas was dealt with different filters before sampling, thus the concentration of plutonium on the filters was different. The radioactive activity of filters was detected and calculated before research. The main property of spectrum of plutonium in filter was investigated. By analyzing the signal intensity of plutonium in filters, the main spectral lines of plutonium on the membrane were detected, by comparing them with blank samples, the available emission spectral lines of plutonium were selected with the method of t?test. Furthermore, the best delay time parameter was determined. By using the proper delay time and detecting condition, the intensity of signals of plutonium was promoted, which is helpful to the determination of plutonium content. Finally, as those samples contain different concentration of plutonium on the filter, by detecting signals of those samples, the standard working curve of uranium was obtained, so quantitative calibration curves within a relatively low concentration range were obtained through the experimental analysis of the filter membrane. The analysis results show that by using the selected spectral lines, namely PuⅡ 443.298 nm, PuⅠ 460.721 nm and PuⅡ 466.389 nm, as the emission intensity of these spectra lines are relatively high, and all of them are free of obstacle spectra lines. The above results indicate that determination bias by using quantitative calibration curves is acceptable, and RSD of the results is less than 3%. These results formed the basis of quantitative analysis of nuclear material by using LIBS technology.