The intent of this program is to experimentally validate and enhance available analytical methods for evaluating the mechanical behavior of nuclear power plant piping containing circumferentially oriented defects. This document describes the results of the approach taken by Battelle to provide state-of-the-art analysis methods to predict the behavior of degraded piping operating at LWR conditions. Section 1 gives a summary of the scope of the program. Section 2 of this report summarizes the technical efforts during the course of this program, discusses the material characterization efforts and describes the full-scale pipe fracture experiments and fracture mechanical analyses conducted. Section 3 discusses the significance of results to LBB and in-service flaw acceptance criteria, and examines the potential impact of characterization evaluations and unusual fracture modes observed in nuclear piping materials on evaluation procedures. Section 4 summarizes implications of the program findings and indicates areas for future study in the area of piping integrity research. 44 refs., 37 figs., 8 tabs.