Spectrophotometric determination of plutonium in highly radioactive liquid waste using an internal standardization technique with Neodymium(III)

Surugaya, Naoki ; Taguchi, Shigeo ; Sato, Soichi ; Watahiki, Masaru; Hiyama, Toshiaki

A simple and rapid spectrophotometric method has been developed for the determination of Pu in highly radioactive liquid waste. This method uses Nd(III) as an internal standard, which enables us to determine the concentration of Pu and to authenticate the whole analytical scheme as well. A Nd(III) standard was mixed with a sample solution and Pu was quantitatively oxidized to Pu(VI) with Ce(IV) in a nitric acid medium, having maximum absorbance at 830 nm. The spectrophotometric measurement of Pu(VI) was subsequently performed to determine the concentration compared with maximum absorbance of Nd(III) at 795nm. The proposed method was validated through comparison experiments with isotope dilution mass spectrometry and was successfully applied to the analysis for the nuclear waste management at spent nuclear fuel reprocessing plants.