Balance of oxygen throughout the conversion of a high-level waste melter feed to glass

Gases evolve from nuclear waste melter feed during conversion to glass in response to heating. This paper is focused on oxygen mass balance based on the stoichiometry of feed melting reactions and evolved-gas analysis data. Whereas O2-producing and -consuming batch-melting reactions are complete in the reacting and primary-foam layers of the cold cap, O2 from redox reactions continues to evolve as long as melt temperature increases, and thus generates secondary foam. Also, we discuss the relationship between the oxygen mass balance and the temperature-dependent iron redox ratio and the O2 partial pressure, as they evolve during the feed-to-glass conversion.