Candidate processes for commercial high-level waste solidification are radiant-heat spray calcination, rotary-kiln calcination, and fluidized-bed calcination. Radiant-heat spray and rotary-kiln calcination have been studied only on a pilot-plant scale; plant-scale fluidizeded solidification of U.S. Atomic Energy Commission high-level wastes has been operating for more than 10 years. Cold pilotlant studies using the radiant-heat spray and fluidized-bed processes are currently underway on simulated commercial wastes. Encouraging results to date show that the existing fluid-bed solidification process pioneered at the Idaho Chemical Processing Plant is applicable to commercial waste processing with some process and equipment modifications. These modifications are mainly in areas connected with uncontrolled heating during postulated collapse of the fluidized bed, off-gas cleanup, and equipment design for compatibility with total remote maintenance.