ACTINIDE CHEMISTRY IN THE FAR-FIELD

The environmental chemistry of the actinides is complicated due both t o the extensive redox and coordination chemistry of the elements and a lso to the complexity of the reactive phases encountered in natural en vironments. In the far field, interactions with reactive surfaces, coa tings and colloidal particles will play a crucial role in controlling actinide mobility. By virtue of both their abundance and reactivity, c lays and other layer aluminosilicate minerals, hydrous oxides and orga nic matter (humic substances) are all identified as having the potenti al to react with actinide ions and some possible modes of interaction are described, together with experimental evidence for their occurrenc e.