Real-time aqueous tritium monitor using liquid scintillation counting

The ability to continuously monitor low-level tritium releases in aqueous effluents is of particular interest to heavy water facilities such as those at the Savannah River Site (SRS) and Canadian CANDU reactors. SRS developed a real-time monitoring system based on flow-through liquid scintillation (LS) counting. Sensitivities of 16 pCi/ml and 1 pCi/ml result from five minute and daily averages of counting data respectively. This sensitivity is about 200 times better than similar methods using solid scintillants. The LS system features uncomplicated sample pretreatment, precise proportioning of the cocktail and sample water, on-line quench corrections, cocktail consumption as low as 0.15 ml/min, and response to changes in environmental tritium in less than 30 min. Field tests demonstrate that conditions necessary for stable analytical results are achieved. ((orig.))