An assessment of radiolytic gas generation: Impacts from Rocky Flats Plant residue elimination alternatives

This report evaluates the Sandia National Laboratory-Albuquerque analytical model that is used to support present wattage limit decisions for various matrix forms from the Residue Elimination Project for Waste Isolation Pilot Plant waste acceptability. This study includes (1) a comparison of the SNL-A model to Rocky Flats Plant models for consistency of assumptions and the phenomena considered in the models, and (2) an evaluation of the appropriateness of the Sandia National Laboratory-Albuquerque model to Rocky Flats Plant residues, considering that the original intent was to model wastes rather than residues. The study draws the following conclusions: (1) only real-time gas generation testing of specific waste streams may provide a sound basis for an increase in the transportation wattage limit of specific waste streams, and (2) the radiolytic gas generation rate from Residue Elimination Project waste emplaced at Waste Isolation Pilot Plant, under worst-case conditions, is not a significant factor in comparison to the total gas generation rate due to radiolysis, microbial degradation, and corrosion