Densification studies of Synroc D for high-level defense waste

摘要: Small- to medium-scale densification experiments were conducted on Synroc D using graphite dies and metal canisters. Pressures at elevated temperatures applied both isostatically (HIP) unidirectionally (HUP). Spray-dried/calcined powders formulated for composite or average sludge compositions exhibited initial packing densities of about 25% theoretical. Final in the range 95 99% theoretical, depending pressure temperature. In final-stage HUP densification, we have found that porosity varies exponentially with time acording well-known expression P + P/sub 0/ exp(-K/sub 0/t). The rate constant (K/sub 0/) has Arrhenius form K/sub = Asigma exp(-E/RT) which includes a stress term. Rate constants are calculated from approximately 20 under wide conditions; activation energies 35 kcal/mole process. HIP leaching results reported variables: (3 30 ksi), temperature (900 1200/sup 0/C), redox calcination method, powder fill density canister material. support conclusion parameters very similar Synroc-D behavior is essentially independent themore » 90 100% theoretical.The collapsible metal-bellows been simulated by means modeling calculations. Radial buckling tendencies also evaluated. Results large-scale reported. Up 50 kg was densified greater than theoretical 36 cm diameter 24 height. These data used as guide make recommendations full-scale canisters.« less