At high neutron exposures where the swelling of AISI 316 exceeds ∼5% the irradiation creep rate at 550°C begins to decline and eventually disappear. Swelling continues to proceed, however, leading to a maximum deformation rate dictated only by that of the steady-state swelling rate or ∼0.33%/displacements per atom (dpa). It is not clear at this point whether large levels of voidage are directly responsible for the decrease in creep rate. There is some evidence to support the possible role of intermetallic precipitate formation, although the mechanism of creep suppression by such precipitates is not known.