Rationale for revised bin-scale gas-generation tests with contact-handled transuranic wastes at the Waste Isolation Pilot Plant

The gas-generation characteristics of contact-handled transuranic waste from Rocky Flats Plant (RFP) and Idaho National Engineering Laboratory (INEL) will be tested at the Waste Isolation Pilot Plant (WIPP) in a series of bin-scale experiments. Bin-scale experiments are necessary because the extreme heterogeneity of CH TRU waste precludes adequate simulation of the waste in the laboratory. A stratified random sample of waste drums will be selected from the collection of drums at RFP and INEL that can be certified for shipment to the WIPP by August 1991. Before the waste is emplaced in the bins, 11 physical characteristics expected to control gas- generation behavior will be measured. These 11 controlling variables'' are expected to apply to all existing and future transuranic waste throughout the Department of Energy complex. Experiments will examine gas generation by radiolysis, microbial degradation, corrosion, and any synergistic mechanisms under many of the environmental conditions that will or may occur in the WIPP repository during the next 10,000 years. Because gas-generation behavior will be interpreted in terms of the controlling variables, gas generation by existing RFP/INEL waste that is not currently shippable, existing waste at other sites, and future waste can be predicted from the results of themore » WIPP bin-scale experiments. The results of the bin-scale experiments will support the WIPP Project's evaluation of compliance with 40 CFR 191, 40 CFR 268, and the National Environmental Policy Act. 55 refs., 13 figs., 18 tabs.« less