Validation of spectrophotometric method for 63Ni activity determination in radioactive waste samples

Abstract This study focuses on the radiochemical separation and activity determination of 63 Ni in radioactive waste sample. A validated spectrophotometric method was employed for the chemical yield determination, replacing the traditional gravimetric approach due to its faster processing time and reduced material consumption. The spectrophotometric method was first validated using an NPL reference sample, ensuring accuracy and consistency. Radiochemical separation was conducted using ion-exchange and extraction chromatography, followed by activity measurement using liquid scintillation counting (LSC). The chemical yield was determined using both spectrophotometry and gravimetry for comparison. The average 63 Ni activity in the radioactive waste sample was found to be 27.9 ± 3.8 MBq/kg.