Determination of plutonium in high active liquid waste by spectrophotometry using neodymium as an internal standard for safeguards analysis

For the determination of Pu in the high active liquid waste (HALW), isotope dilution mass spectrometry (IDMS) has been applied to verification analysis at Tokai Reprocessing Plant. IDMS has been considered as the most reliable analytical technique for accountability measurement of Pu in spent fuel reprocessing plant. However, it takes quite long time for inspector to obtain an analytical result because inspection sample has to be transported to safeguards analytical laboratory for off-site analysis. In order to resolve this disadvantage, a rapid verification analysis of Pu in HALW by conventional spectrophotometer using Nd as an internal standard was proposed to achieve on-site verification analysis. In this method, Nd standard is intended to be provided by International Atomic Energy Agency (IAEA) so that an inspector can independently control it not only as an internal standard but also as an authentication purpose. The validation analysis was performed by IDMS. It was found that the values of Pu concentration obtained by proposed method were in good agreement with those obtained by IDMS. Therefore the proposed method can be expected for the application to the verification analysis. (author)