The commercial Light Water Reactors operating within the United States have been in service from about 20 to 35 years. These plants include buried Service Water piping systems primarily made from low carbon steel. This piping at several plants has been subject to aging over the years, resulting in degradation and corrosion that may require replacement of the piping. Due to the advantageous cost and durability of High Density Polyethylene (HDPE) piping (as demonstrated in other commercial industries), the nuclear power industry has expressed interest in replacing steel buried Service Water Piping in Nuclear Power Stations with HDPE Pipe. To assist in this effort EPRI has funded and supported the work summarized in this paper to develop design criteria for HPDE Pipe. The paper provides design criteria for High Density Polyethylene (HDPE) pipe made from PE 3408 resin. It also provides the technical basis for the proposed criteria. This paper deals primarily with the design of the piping in relation to its interface with the soil in which it is buried. The criteria primarily is derived from current analysis methodology for steel and concrete buried pipe while incorporating changes required to account for the properties and behavior of HDPE pipe. The proposed analysis methodology described herein has evolved into a proposed ASME Boiler and Pressure Vessel Code, Section III, Division I, Design Code Case for consideration by the Section III, Subcommittee on Nuclear Power.
