[en] This document is a review of the 1987 update of detailed reference powerplant cost estimates. This distribution is the latest in a series published since 1978. The overall program purpose is to provide periodically updated, detailed base construction cost estimates for large nuclear electric operating plants. These data, which are representative of current US powerplant construction cost experience, are a useful contribution to program planning by the Office of the Assistant Secretary for Nuclear Energy. The ninth update includes three new models as a basis for projecting future costs of both small and large nuclear power plants and examining the potential for cost reduction by incorporation of improved and advanced design features. The models designated as improved include the advantages of modular construction and standardized approach to design and construction. The advanced model includes many of the features of the improved data models as well as application of passive or near-passive safety systems and design simplification