Mixer-settler runs with tri-iso-amyl phosphate and tri-n-butyl phosphate for the aqueous reprocessing of U–Zr alloy fuels

Investigation on the Separation of Zr Using Trialkyl Phosphate based Solvents: A Combined Experimental and Theoretical Studies with insights from EXAFS Analysis

“…In our earlier papers, the detailed schematic representation of the mixer-settler unit is presented. 19 Extraction and strip processes were performed in a counter-current method using a 16-stage mixer-settler unit constructed from a monolithic polypropylene block. 19 Mixing of the organic and aqueous phases was accomplished through air pulsing in the column by alternating the vacuum and pressure using a solenoid valve controlled by a cyclic timer.…”

“…A ternary metallic alloy fuel of U-19%Pu-10%Zr has been used in fast reactors due to their better thermo-physical properties. , Metal fuels can be reprocessed either by PUREX process or by a pyrometallurgical reprocessing method. In the recent past, reprocessing of metallic alloy fuels such as U–Zr and U–Pu–Zr by aqueous based PUREX process as an alternate to the pyro-processing of metallic fuels has been examined in our laboratory. , In this method U–Zr and U–Pu–Zr metallic fuels were dissolved in nitric acid medium followed by separation of U and Pu from Zr using tri- n -butyl phosphate (TBP) and tri-iso-amyl phosphate (TiAP) based solvents. , Zr is not extracted by TBP in the presence of U and Pu in U–Zr and U–Pu–Zr feed solutions; hence, it is transferred to raffinate streams (HLW). A solution of Zr in nitric acid medium (raffinate) is generated from the mixer-settler runs. , The concentration of Zr in raffinate streams is found to be in the range of 4–6 g/L.…”

“…In the recent past, reprocessing of metallic alloy fuels such as U–Zr and U–Pu–Zr by aqueous based PUREX process as an alternate to the pyro-processing of metallic fuels has been examined in our laboratory. , In this method U–Zr and U–Pu–Zr metallic fuels were dissolved in nitric acid medium followed by separation of U and Pu from Zr using tri- n -butyl phosphate (TBP) and tri-iso-amyl phosphate (TiAP) based solvents. , Zr is not extracted by TBP in the presence of U and Pu in U–Zr and U–Pu–Zr feed solutions; hence, it is transferred to raffinate streams (HLW). A solution of Zr in nitric acid medium (raffinate) is generated from the mixer-settler runs. , The concentration of Zr in raffinate streams is found to be in the range of 4–6 g/L. Presence of such large quantities of Zr may lead to the formation of separate phases during immobilization of waste in a sodium borosilicate glass matrix.…”

“…3,4 In this method U−Zr and U−Pu−Zr metallic fuels were dissolved in nitric acid medium followed by separation of U and Pu from Zr using tri-n-butyl phosphate (TBP) and tri-iso-amyl phosphate (TiAP) based solvents. 3,5 Zr is not extracted by TBP in the presence of U and Pu in U−Zr and U−Pu−Zr feed solutions; hence, it is transferred to raffinate streams (HLW). A solution of Zr in nitric acid medium (raffinate) is generated from the mixer-settler runs.…”

“…A solution of Zr in nitric acid medium (raffinate) is generated from the mixer-settler runs. 3,5 The concentration of Zr in raffinate streams is found to be in the range of 4−6 g/L. Presence of such large quantities of Zr may lead to the formation of separate phases during immobilization of waste in a sodium borosilicate glass matrix.…”