Review—Evolution of the Development of In-Sodium Oxygen Sensor and Its Present Status

Abstract

Chronological account on the development of oxygen sensors for use in liquid sodium has been made and reviewed. Factors like chemical compatibility with sodium, electrolytic domain boundary, electrical conductivity, thermomechanical property, etc. of yttria doped thoria (YDT) and yttria / calcia stabilized zirconia (YSZ or CSZ) were compared. YDT was found to be superior to zirconia based electrolytes for the intended application in sodium. Analyses of different designs evidenced improved life of sensors using YDT in thimble form.

Impact of liquid sodium corrosion on microstructure and electrical properties of yttrium-doped thoria prepared by co-precipitation

“…typically below 1 ppm), which corresponds to highly-purified and nuclear-grade sodium. This result then differed significantly from the value reported by Jayaraman, who argued for a threshold concentration of 1250 ppm at 500°C [16]. Nevertheless, this value corresponded to the oxygen saturation at 500°C and was thus highly doubtful.…”

“…Even if the failure of oxygen electrochemical probes operating in liquid sodium was generally correlated to the corrosion of the electrolyte ceramics [16], only few studies were dedicated to the evolution of the electrical properties for yttrium-doped thoria consequently to the immersion of the materials in liquid sodium. Impedance spectroscopy measurements were then conducted on corroded samples in order to point out if the blocking contributions, usually assigned to the presence of grain boundaries in the ceramics, could be affected by the intergranular attack of the pellets.…”

“…Even if yttrium-doped thoria is generally considered to be much less sensitive to sodium corrosion compared to zirconia [16], also frequently used in oxygen sensors [17], only very few studies are reported in the literature regarding its chemical durability. Indeed, different potential failures were evidenced, but appear to be mainly linked with mechanical effects [16,[18][19][20][21]. Fractures often occurred very rapidly after contact with liquid sodium between 360 and 400°C, but more likely due to thermal shock rather than to sodium corrosion [16,22].…”

“…Indeed, different potential failures were evidenced, but appear to be mainly linked with mechanical effects [16,[18][19][20][21]. Fractures often occurred very rapidly after contact with liquid sodium between 360 and 400°C, but more likely due to thermal shock rather than to sodium corrosion [16,22]. Several authors also reported on the embrittlement of the electrolyte ceramic through the formation of cracks during Na-testing at 400°C.…”

Recent Advances in the Use of Biomass‐Derived Activated Carbon as an Electrode Material for Electroanalysis

“…[3,4] They are classified based on the method adopted for sensing, including optical, [5][6][7][8] electrochemical, [9,10] electrical, [11] thermometric, [12] mass sensitive, [13] magnetic [14][15][16] etc. They can also be classified based on the type of analyte into different types, including pH electrodes [17] and sensors for metal ions and determining gases, [18][19][20] as well as the mode of application into in vivo [21] and in vitro [22] sensors for process monitoring. Among these methods, electrochemical methods possess remarkable features, such as high sensitivity, short response time, low cost, simplicity of instrumentation, the possibility of miniaturization, and integration with portable devices.…”