Kinetic study of sodium-water reaction phenomena by differential thermal analysis

Kikuchi, Shin  ; Seino, Hiroshi ; Kurihara, Akikazu ; Ohshima, Hiroyuki

In this work, we studied the kinetics of Na-NaOH reaction as secondary surface reaction in the SWR by using DTA technique. Melting points of Na and NaOH, phase transition temperature of NaOH, Na-NaOH reaction temperature, and the decomposition temperature of NaH were identified from DTA curves. Na, NaOH, and NaO as major chemical species were identified from the XRD analysis of the residues after the DTA experiment. It was inferred that NaO could be generated as Na-NaOH reaction product. Based on the measured reaction temperature, the first-order Arrhenius type rate constant of NaO generation and these related kinetic parameters were obtained by the application of kinetic laws. According to this kinetic study, it was found that NaO generation should be considered during SWR.