Release of radioactivity from waste packages

The rates at which nuclides contained in high-level wastes are released into solution may be controlled by chemical kinetics, equilibrium solubilities, or solid-state diffusion. Recent research has focused on equilibrium solubility as a relatively predictable factor that in many situations can be expected to hold release rates to low levels. Simple analytic solutions based on equilibrium solubility are available to describe dissolution in various physical situations. For more soluble elements, chemical kinetics may need to be invoked if low release rates must be demonstrated.