Pa solution chemistry study for uranium waste management, 1; Purification of Pa-231 and UV-Vis-NIR spectroscopy

Kirishima, Akira*; Watanabe, Masayuki   ; Kitatsuji, Yoshihiro  ; Segawa, Yukari; Aoyagi, Noboru   ; Akiyama, Daisuke*; Sato, Nobuaki*

Pa is one of the most important nuclide in the safety evaluation due to its long life time, 32760 years. In the case of shallow geological disposal of Uranium waste, Pa which is a daughter of Uranium would become dominant nuclei for public exposure of radioactivity after about 1000 year from the disposal. We start to understand some basic properties of Pa such as hydrolysis, stability constants with simple ligands and spectroscopic parameters because little is known about essential properties of Pa. In this presentation, we will report some results on the purification of Pa with solvent extraction, UV-VIS-NIR spectroscopy of Pa and stability constant with fluoride.