光纤光谱技术在乏燃料后处理工艺分析中的应用进展

Development of fiber optic spectroscopy technology in spent fuel reprocessing process analysis

对光纤光谱技术在后处理工艺分析中的研究进展进行了综述。紫外-可见光谱主要用于后处理工艺料液中铀、钚浓度及价态[主要为U(Ⅳ)、Pu(Ⅲ)和Pu(Ⅳ)]的分析。液芯波导毛细管技术与紫外-可见光谱的组合使用大大提高了不同价态钚离子的检测限。近红外光谱适用于不同镎、钚价态[Pu(Ⅳ)和Pu(Ⅵ)]及含量的测定,尤其是对于水相和有机相中硝酸浓度的测量,具有检出限低、测量结果准确等优点。U(Ⅵ)和硝酸在拉曼光谱中具有特征吸收峰,可通过拉曼光谱进行测量,且离子之间的相互干扰较小。此外,拉曼光谱还可用于CO_(3)^(2-)、NO_(3)^(-)、SO_(4)^(2-)等阴离子的检测。后处理工艺料液组成复杂,没有任何一种光谱技术可以涵盖所有测量物种。光谱融合技术可以同时定量复杂工艺料液中的多种关键成分(铀、钚和硝酸等),具有显著优势。在将来,需重点开展在线光纤光谱技术、光谱融合、化学计量学解谱等关键技术,提高光谱测量结果稳定性,使后处理工艺分析更加在线化和智能化。

The development of fiber optic spectroscopy in reprocessing process analysis was reviewed.Ultraviolet�visible spectroscopy was mainly used for analyzing the concentration and valence state of uranium and plutonium(mainly U(Ⅳ),Pu(Ⅲ),and Pu(Ⅳ))in the reprocessing process feed liquid.The combination of liquid waveguide capillary technology and ultraviolet-visible spectroscopy greatly improves the detection limit of plutonium ions with different valence states.Near-infrared spectroscopy is suitable for the determination of different valence states and contents of neptunium and plutonium[Pu(Ⅳ)and Pu(Ⅵ)],especially for the measurement of nitric acid concentration in aqueous and organic phases.It had the advantages of low detection limit and accurate measurement results.U(Ⅵ)and nitric acid had characteristic absorption peaks in Raman spectroscopy,which could be measured through Raman spectroscopy,and the mutual interference between ions was small.In addition,Raman spectroscopy can also be used for the detection of anions such as CO_(3)^(2-),NO_(3)^(-),and SO_(4)^(2-).The composition of the reprocessing process is complex,and no single spectral technique could cover all measured species.Spectral fusion technology could simultaneously quantify multiple key components(such as uranium,plutonium,and nitric acid)in complex process materials,which had significant advantages.In the future,it is necessary to focus on key technologies such as online fiber optic spectroscopy,spectral fusion,and chemometric spectral analysis to improve the stability of spectral measurement results and make reprocessing process analysis more online and intelligent.