The performance of pressurized water reactor (PWR) power plants is evaluated through analysis of power generation records, and directions are given in which measures might be effectively sought for further improvement of plant performance and productivity. The boundary between what has already been achieved in the performance of such plants and what remains to be done in development and demonstration is clearly identified. To supplement the traditionally adopted “capacity factor” (average power/nominal capacity) for assessing the improvements gained in the performance of uprated fuels and reactor cores, additional new yardsticks are proposed to represent the productivity of nuclear fuel and the reactor core. For evaluating the performance of fuel, the proposed variable is based on the correlation between specific power and annual core average burnup, i.e., thermal power and annual heat generation per unit mass of fuel. Similarly for the reactor core, the variable is based on the correlation between thermal power and heat generation per unit core volume and per unit area of core cross section. The advantages of adopting the proposed variables are discussed. Operating experience with PWR plants indicates that the relatively short service life of nuclear fuel, compared with the core structure and other reactor components, has permitted reliable, effective service of uprated fuel in high-performance plants to be demonstrated over periods extending beyond the service life of individual fuels. This is not the case, however, with the core structure and other reactor components: Most existing plants have been in service for less than half of the expected service life of these components, therefore data available today are insufficient for evaluation of their long-term performance. An analysis is presented on possible repercussions to be expected from the current trend in development, which tends toward higher core power rating, and it is pointed out that certain plant components will possibly come to be exposed to increasingly severe thermal conditions, which calls for further efforts in development and demonstration to ensure their continued reliability in service.