Model 1315 -Pre-Method
Method 1315 is used to determine the mass transfer rate of inorganic constituents from a monolithic, or compacted granular material, under diffusion-controlled release conditions. Diffusion, the movement of molecules from an area of high concentration to an area of low concentration, is the predominant mass-transfer mechanism when water flows around rather than through a material with low hydraulic conductivity relative to surrounding materials.
The method is not intended for the release of semivolatile or volatile organic compounds.
This method is similar to the American National Standard Institute/American Nuclear Society Standard 16.1 “Measurement of the Leachability of Solidified Low-Level Radioactive Wastes by a Short-term Test Procedure.” The method entails immersing a monolithic or compacted granular specimen in reagent water for a specified duration, and then removing the specimen from the water and re-immersing it in fresh reagent water.
This process is repeated for a total of nine leach intervals. The duration of each immersion differs according to this schedule.
The concentrations of targeted constituents in the eluate from each leach interval are determined and plotted as a function of time, as a mean interval flux, and as cumulative release as a function of time. The data is used to determine mass transfer properties.