Geologic migration potentials of technetium-99 and neptunium-237.
Relatively mobile TcO(+)(-) and NpO(2)(+) can be chemically reduced to less soluble oxidation states in the presence of igneous rocks, as predicted by oxidation-reduction measurements. Current risk assessments, which consider technetium and neptunium as potentially capable of migrating from high-level radioactive waste repositories, may be overestimating their potential hazard to the public since the Fe(II) content of many subsurface waters may maintain these elements in less soluble oxidation states.
Bondietti
E A
EA
Francis
C W
CW