Cold leg integrity evaluation. Final report. [PWR]

The objective of this study was to evaluate the margin of safety against a large break in the cold leg piping system of a Pressurized Water Reactor (PWR) power plant. The study focused on the cold leg piping systems of Arkansas Nuclear-1, St. Lucie-1, and Farley-1 PWR power plants. All components of the cold leg piping systems were examined with the exception of the pressure vessel nozzles and the injection laterals. Both axial and circumferential cracks were postulated to exist at critical areas within the piping system. Their growth as part through and then through wall cracks was synthesized within the framework of Linear Elastic Fracture Mechanics (LEFM). The margin of safety was assessed in terms of through-wall crack development, leak rate, and the formation of a large break. The latter criterion was implemented in terms of both LEFM and plastic collapse concepts.