Crucibles made of materials resistant to liquid actinide metals, as follows: a. Crucibles having both of the following characteristics: 1. A volume of between 150 cm 3 (150 ml) and 8000 cm 3 (8 liters); and 2. Made of or coated with any of the following materials, having a purity of 98% or greater by weight: a. Calcium fluoride (CaF2); b. Calcium zirconate (metazirconate) (CaZrO3); c. Cerium sulfide (Ce2S3); d. Erbium oxide (erbia) (Er2O3); e. Hafnium oxide (hafnia) (HfO2); f. Magnesium oxide (MgO); g. Nitrided niobium-titanium-tungsten alloy (approximately 50% Nb, 30% Ti, 20% W); h. Yttrium oxide (yttria) (Y2O3); or i. Zirconium oxide (zirconia) (ZrO2); b. Crucibles having both of the following characteristics: 1. A volume of between 50 cm3 (50 ml) and 2000 cm3 (2 liters); and 2. Made of or lined with tantalum, having a purity of 99.9% or greater by weight; c. Crucibles having all of the following characteristics: 1. A volume of between 50 cm3 (50 ml) and 2000 cm3 (2 liters); 2. Made of or lined with tantalum, having a purity of 98% or greater by weight; and 3. Coated with tantalum carbide, nitride, boride, or any combination thereof.