Spray solidification of nuclear waste. [Calciner operation]

Design and performance of atomizing nozzles for spray calcination of high-level wastes

“…Both steam and preheated air cause nozzle plugging in internal-mix nozzles by drying the waste in the nozzle (Bonner, Blair and Romero 1976). Conventional external-mix nozzles are also heated excessively by hot air or steam and can plug from waste dried in the nozzle.…”

“…The spray calcination process is extremely versatile for drying widely varying waste compositions (Bonner, Blair and Romero 1976). At PNL, the spray calciner has been operated coupled to in-can melters and ceramic melters for the production of a vitrified product, and has also produced calcine for pellets and associated alternate waste forms.…”

West Valley demonstration project: alternative processes for solidifying the high-level wastes

“…Calcine particle size distributions are shown in Figure 10.15 (Bonner, Blair and Romero 1976) for low-sodium acidic-type waste and Figure 10.16 for alkaline low-sodium waste (Larson 19S0). While 65% of the total number of particles for acidic waste are in the diameter range of 1 to 5 ~m.…”

“…During the development of the pot-calcination process ORNL, a processing 10.41 (a) The calcine particle density is variable (about 4.3 g/cm3 average) because particles from simulated defense waste slurries remain as separate and distinct compounds, i.e., the calcine is composed of Mn02 particles, NiO particles, zeolite particles, particles containing water-soluble compounds, etc. (b) Adapted from Bonner, Blair and Romero 1976; temperature of 900 0 C was found to achieve complete nitrate decomposition and thus to assure that sealed canisters of calcine would not pressurize. Such treatment of the WNYNSC calcine would first result in melting the calcine followed by solidification into a monolith.…”

“…Also, a high-nitrate calcine is produced, which could cause container pressurization from gases generated from radiolytic decomposition. Pacific Northwest Laboratory has had experience (Bonner, Blair and Romero 1976; …”