Plutonium segregation during normal operation is not expected in light water reactor (LWR) plutonium recycle fuels, but it could occur if these fuels were operated in a sustained overpower condition. Existing thermal performance and neu-tronic computer codes have been used to compare the effects of postulated segregation with the behavior of homogeneous fuels. Central void formation, which should accompany plutonium segregation, reduces fuel temperatures markedly; but even if a central void is assumed not to form, the fuel’s centerline temperature stored energy, and melting point are not significantly affected by the postulated segregation. It is concluded that plutonium segregation is not an important phenomenon in LWR plutonium recycle fuels.