Stability constants of uranium(IV)-α-isosaccharinic acid and gluconic acid complexes

Conditional and pH independent stability constants have been determined for U(IV) α-isosaccharinic acid (ISA) and gluconic acid (Gl) complexes, under anaerobic and carbonate-free conditions, from pH 3 to 14. The constants are needed for nuclear waste repository performance assessment purposes. The constants were obtained by developing an approach based on the solubility product of amorphous UO2 ·2H2O. The derived pH independent log β values for U(OH)4ISA and U(OH)4Gl were 49±2 and 50±1 respectively.