During nuclear fuel reprocessing, monitoring of U and Pu concentration in every stage is very essential for process control purpose. A simple and fast spectrophotometric method for a simultaneous estimation of U and Pu in Plutonium Uranium Recovery by Extraction (PUREX) process's tail end stream like Pu product where Pu concentration is much richer than that of U is described here. The method involves reduction of the bulk amount of Pu to Pu(III) using ascorbic acid in 1 M HNO₃. Visible absorption peaks were measured at 416 nm for U and at 600 nm for Pu using a fiber optic probe of path length 40 mm. The methodology enables quantification of U and Pu concentration in the Pu product samples with a precision of 2.8 and 2.1%, respectively.