Californium Purification and Electrodeposition

The staff at the Radiochemical Engineering Development Center, located at Oak Ridge National Laboratory, produced a 6.3 ± 0.4 GBq (1.7 ± 0.1 Ci) ²⁵²Cf source for the Californium Rare Isotope Breeder Upgrade (CARIBU) project at Argonne National Laboratory’s Argonne Tandem Linac Accelerator System. The source was produced by electrodeposition of a ²⁵²Cf sample onto a stainless steel substrate, which required material free from excess mass for efficient deposition. The resulting deposition was the largest reported ²⁵²Cf electrodeposition source ever produced. Several different chromatographic purification methods were investigated to determine which would be most effective for final purification of the feed material used for the CARIBU source. The separation of lanthanides from the Cf was of special concern. The separation, using ¹⁴⁵Sm, ¹⁵³Gd, and ²⁴⁹Cf as tracers, was investigated using BioRad AG 50X8 in a hydroxyisobutyric acid, Eichrom LN resin in both HNO3 and HCl, and Eichrom TEVA resin in NH₄SCN. The TEVA NH₄SCN system was found to completely separate ¹⁴⁵Sm and ¹⁵³Gd from ²⁴⁹Cf and was adopted into the purification process used in purifying the ²⁵²Cf.