Monitoring of Oxygen in Simulated Electrolytic Reduction Salt of Pyroprocessing Using Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) was explored as a method of monitoring oxygen (O) concentration in electrolytic reduction salt of pyroprocessing. Simulated salt samples were fabricated, and each sample was put in a transparent and sealed vial filled with argon gas. An neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulse was applied to the sample through the vial surface, and the optical emission spectrum was measured. O(I) 777.2 nm lines were clearly identified in the spectrum of a sample containing Li2O, and the intensity of the O peak and the intensity ratio of O and lithium (Li) peaks, in which Li was used as the normalization, increased linearly as the O concentration in the salt sample was increased. The limit of detection and root mean square error were calculated for the cases of O peak area, O peak height, peak area ratio of O-Li, and the peak height ratio of O-Li, and all the cases could indicate that the O concentration in the electrolytic reduction salt was out of normal range. Our result shows that LIBS has the possibility to be used as a method for monitoring of O in electrolytic reduction salt.