Proportional counting of tritium gas generated by polymer electrolyte membrane (PEM) electrolysis

The combination of an Ir/Pt PEM electrolyzer with a 1 L flow-through gas proportional counter was characterized for the quantification of tritium in water. The goal of the detection system is to quantify at concentrations below the Environmental Protection Agency (EPA) primary drinking water standard (740 Bq/L) with minimal expendables. The detector operating voltage, efficiency, background count rate of the passively shielded counter were measured in order to calculate the minimum detectable concentration of the detection system. The electrolyzer fractionation factor beta (e) value deduced from the measurement of gas phase activity concentrations generated from tritium aqueous standards was found in good agreement with literature values.