Evaluation of novel leaching assessment for nuclear waste glasses

The applicability of the Environment Protection Agency (EPA) leaching protocol, EPA 1313, to low activity waste from the Hanford site (USA), immobilized in a glass matrix, is evaluated. The protocol, established for industrial wastes, soils, sludges, construction materials and mining wastes, measures the release of elemental constituents as a function of pH. We present the results of an assessment of the effects of particle size, sample mass and solution pH on the leachability of the Immobilized Low Activity Waste (ILAW) simulant glass, LAW-A44, in an attempt to validate the EPA 1313 protocol for use on glass materials. Several amendments are proposed, including defining an upper and lower limit for particle size and performing experiments in solutions buffered to the desired pH. The ultimate goal of this research is to establish a new glass leachability assessment for disposal of ILAW glass in the Integrated Disposal Facility at Hanford, which does not constrain the glass formulation, unlike the current leaching protocols, that are not reflective of the conditions of disposal.