The uniformity and stability of ThO2-Bi dispersions (with 350 ppm each of Mg and Zr) were measured in fifty pound batches containing up to 11.5% ThO2 and also in circulating experiments carried out in a ½-in. IPS pumped loop at ThO2 concentrations up to 7.4%. Good results were obtained in all experiments where gas entrainment was prevented or eliminated.