[en] Based on analogies to the Arrhenius approach for aging predictions in thermooxidative environments, we have derived a predictive methodology appropriate to combined radiation-thermal environments. It is shown how the approach manipulates data from accelerated environmental conditions to make meaningful predictions for low voltage cables under dose-rate/temperature conditions characteristic of ambient nuclear power plant aging. Since analyses are only possible for homogeneously-oxidized materials, calculations are included which give strong evidence that homogeneous oxidation is appropriate to the ambient nuclear power plant aging of most low voltage cables. Data consistent with the methodology are presented for a number of cable materials