Assessment of metal and chlorine emissions from molten salt oxidation using laser-induced breakdown spectroscopy

Author(s):  
Steven Buckley ◽  
Jaya Kumar P Patil ◽  
Jerry S Salan
Author(s):  
Ammon Williams ◽  
Supathorn Phongikaroon

Pyroprocessing of used nuclear fuel has shown potential as an alternative fuel reprocessing technology to the traditional aqueous technology. Having a clear picture of the actinide, fission product, and rare-earth elements within the salt in realtime is important from processes control, efficiency and material safeguards perspectives. However, measuring the molten salt electrolyte composition within the system is challenging due the high temperature and radiation involved. Laser induced breakdown spectroscopy (LIBS) has been proposed to measure the molten salt composition via a static liquid surface or solid surface approach. These approaches can yield compositional results near real-time; however, concerns with sample homogeneity, splashing, and poor repeatability present significant challenges. A novel molten salt aerosol-LIBS system has been developed to mitigate some of the aforementioned challenges. Here, modifications to the system using a 1-jet nebulizer and sampling chamber are being discussed. Preliminary results demonstrate the advantages and success of the modifications. Experiments were conducted to optimize the spectrometer gate delay and results indicate that the optimal gate delay is greater than 9 μs. In addition, the percent relative standard deviations (%RSD) for this system were found to be approximately 7%.


2018 ◽  
Vol 72 (7) ◽  
pp. 1029-1039 ◽  
Author(s):  
Ammon Williams ◽  
Supathorn Phongikaroon

In this current study, the molten salt aerosol–laser-induced breakdown spectroscopy (LIBS) system was used to measure the uranium (U) content in a ternary UCl3–LiCl–KCl salt to investigate and assess a near real-time analytical approach for material safeguards and accountability. Experiments were conducted using five different U concentrations to determine the analytical figures of merit for the system with respect to U. In the analysis, three U lines were used to develop univariate calibration curves at the 367.01 nm, 385.96 nm, and 387.10 nm lines. The 367.01 nm line had the lowest limit of detection (LOD) of 0.065 wt% U. The 385.96 nm line had the best root mean square error of cross-validation (RMSECV) of 0.20 wt% U. In addition to the univariate calibration approach, a multivariate partial least squares (PLS) model was developed to further analyze the data. Using partial least squares (PLS) modeling, an RMSECV of 0.085 wt% U was determined. The RMSECV from the multivariate approach was significantly better than the univariate case and the PLS model is recommended for future LIBS analysis. Overall, the aerosol-LIBS system performed well in monitoring the U concentration and it is expected that the system could be used to quantitatively determine the U compositions within the normal operational concentrations of U in pyroprocessing molten salts.


Author(s):  
Gregory Hull ◽  
Hugues Lambert ◽  
Kiran Haroon ◽  
Paul Coffey ◽  
Timothy Kerry ◽  
...  

Pyroprocessing of spent nuclear fuels is an electrochemical separation method where spent metallic fuel is dissolved in a molten salt bath to allow uranium (U) and plutonium (Pu) to be isolated from fission products (FPs) and other impurities.


2014 ◽  
Vol 68 (9) ◽  
pp. 937-948 ◽  
Author(s):  
Arel Weisberg ◽  
Rollin E. Lakis ◽  
Michael F. Simpson ◽  
Leo Horowitz ◽  
Joseph Craparo

2020 ◽  
Vol 92 (2) ◽  
pp. 20701
Author(s):  
Bo Li ◽  
Xiaofeng Li ◽  
Zhifeng Zhu ◽  
Qiang Gao

Laser-induced breakdown spectroscopy (LIBS) is a powerful technique for quantitative diagnostics of gases. The spatial resolution of LIBS, however, is limited by the volume of plasma. Here femtosecond-nanosecond dual-pulsed LIBS was demonstrated. Using this method, the breakdown threshold was reduced by 80%, and decay of continuous radiation was shortened. In addition, the volume of the plasma was shrunk by 85% and hence, the spatial resolution of LIBS was significantly improved.


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