[2C10-14] Migration/Sorption1

[2C12] Solubility of Niobium under high Calcium concentration and alkaline conditions

*Saki Ohira¹, Takeyasu Abe¹, Yoshihisa Iida¹ (1. Japan Atomic Energy Ergency)

Keywords:Nb, Ca, Solubility, Solubility-limiting solid

Niobium-94(⁹⁴Nb) is an important radionuclide in the safety assessment of radioactive waste disposal. Solubility-limiting solid and solution species of Nb under high Calcium (Ca) concentration and alkaline conditions remain unclear. The results of Nb solubility experiments in this study suggest that the Nb solubility under high Ca concentration and alkaline conditions would be limited by solubility-limiting solid Ca₄Nb₆O₁₉ (am) and solution species Nb(OH)₆^-.