One consequence of a flux of vacancies towards sinks is a corresponding flux of atoms away from the sink. If vacancies are not annihilated or recombined before collecting at sinks, they will form voids. At sufficiently high temperature, dependent on the material, these voids can fill with gases from the decomposition of the alloy, leading to swelling in the material. This is a tremendous issue for pressure sensitive or constrained materials that are under constant radiation bombardment, like pressurized water reactors. In many cases, the radiation flux is non-stoichiometric, which causes segregation within the alloy. This non-stoichiometric flux can result in significant change in local composition near grain boundaries, where the movement of atoms and dislocations is impeded. When this flux continues, solute enrichment at sinks can result in the precipitation of new phases.