Sodium zirconium phosphate and calcium zirconium phosphate, two potential radioactive waste forms, were treated with fluoride, and different methods of sintering were evaluated. Different compositions were prepared by adding calcium fluoride to sodium zirconium phosphate and  sodium fluoride to calcium zirconium phosphate. These mixtures were calcined in a microwave furnace and then sintered. The increase in  densification of the samples sintered in a hot isostatic press were observed to be nearly uniform, while other samples that were sintered in a microwave and in a resistance furnace were in homogeneous. The concentration of in homogeneities was higher in fluorinated samples prepared  under closed conditions in a hot press than samples prepared under microwave conditions in air.