Millimeter-Wave Measurements at 137 GHz of DWPF Black Frit Glass Flow and Salt Layer Pooling in a Pilot Scale Melter

Introduction The vitrification of nuclear waste in joule-heated melters is a costly multi-decade national effort. Current operations at the Defense Waste Processing Facility (DWPF) and future operations at the Waste Treatment Plant (WTP), now under construction at Hanford, rely on predictive models because of the lack of on-line monitoring of most processing parameters. This necessitates conservative operation to take into account uncertainties in the modeling and the ability to control actual input parameters. It also makes the operations susceptible to unpredictable anomalies such as foaming, liquidus crystallization, noble metals build up, and salt layer formation. Predictive modeling will become increasingly more difficult in time as the waste glass chemistry evolves with changes in the waste feed compositions. Comprehensive on-line monitoring of the vitrification process would alleviate the uncertainties, improve processing efficiencies (waste loading and throughput), and safeguard the facilities from anomalies.