Development of a separation method for molybdenum from zirconium, niobium, and major elements of rubble samples

A method for separation of Mo from Zr, Nb, and other major elements of rubble samples from the Fukushima Daiichi Nuclear Power Station (FDNPS) was developed to enable 93Mo assay of the rubble samples. Although 93Mo analysis has been reported in a few studies, the known separation method is tedious and time consuming, or the target is a simple material. Therefore, a simple and rapid protocol for the separation of a complex material, i.e., the rubble sample, was developed in this study. Firstly, loss of Mo during the digestion of simulated rubble samples was evaluated. Next, weight distribution coefficients (Kd's) of Zr, Nb, and Mo between an extraction chromatographic resin (tetra valent actinide resin, TEVA resin) and acid solutions (HF-HCl and HF-HNO3 solutions) were determined to obtain suitable solution conditions for the separation of Mo from Zr and Nb. Based on the obtained Kd's, a chromatographic separation scheme was designed and applied to the digested solution of the simulated rubble sample. Consequently, Mo was successfully separated from Zr, Nb and other major metal ions of the simulated rubble sample.