Analysis of hydride and oxide deposition and resolution in sodium in relation to plugging meter behaviour

Galvanic cell hydrogen and oxygen meters have been used in a study of plugging meter behaviour. The hydrogen and oxygen concentrations have been controlled in a sodium loop to give high saturation temperatures with respect to hydride and low for oxide and vice versa, and precipitation and dissolution characteristics for hydride and oxide have been observed. Multiple break phenomena have been briefly examined. Oxide was found to exhibit induction periods prior to nucleation on the plugging meter orifice in contrast to hydride which nucleated rapidly. The plugging characteristics for hydride were more rapid than for oxide and some conclusions have been drawn over the nature of the hydride deposit. Mass transfer coefficients have been estimated for hydride and oxide precipitation. (author)