RECOVERY AND PURIFICATION OF U-234 FROM AGED MEDICAL GRADE (PUO2)-PU-238 USING A CHEMICAL PROCESS-BASED ON CHROMATOGRAPHIC COLUMNS COMBINING EXTRACTION AND REDOX PROPERTIES

U-234 of high radiochemical and isotopic (99.96%) purity was produced at the half-gram scale by chemical treatment of aged medical grade (Pu O2)-Pu-238 stocks. The chemical process designed and used features ori ginal steps including: (i) Dissolution of (PuO2)-Pu-238 in aqueous HNO 3 medium at room temperature with electrogenerated Ag(II). (ii) U-234/ Pu-238 separation cycles mainly performed using chromatographic column s which exhibit simultaneous extraction and redox properties and compr ising a -hexyl)phosphorodithioic/tri-n-butylphosphate/SiO2 stationary phase. These columns extract U(VI) and reduce Pu(IV) to Pu(III) which escapes the columns. The U-234 recovery yield for the overall process was close to 90%, with an excellent decontamination factor (DF) U-234( Pu-238) of >10(8).