In contemporary designs of flowsheets for reprocessing the spent nuclear fuels, neptunium is often termed as a contaminant. During partitioning of uranium and plutonium, its behaviour can be controlled by chemical means. Still its distribution in Purer extraction system is important. In this paper, reported data have been analysed and unique empirical equations for predicting neptunium distribution in 30% TBP/n-dodecane system are reported.