The Dow Chemical Company's bimodal polyethylene resin has been chosen by AmerenUE's Callaway Nuclear Power Plant located near Fulton, Missouri in its buried essential service water (ESW) pipe system. The company's DOW CONTINUUM™ DGDA-2492 BK Bimodal Polyethylene Resin replaced the previously used carbon steel for the purpose. The Dow resin was specified as an American Society for Testing and Materials (ASTM) PE 4710 material for use in 36-inch diameter pipe at the Callaway power plant. This marks the first use of polyethylene in a nuclear safety related application. Callaway submitted an American Society of Mechanical Engineers (ASME) relief request to the Nuclear Regulatory Commission (NRC) to allow the use of high-density polyethylene (HDPE) for buried portions of the Callaway ESW system and received a safety evaluation from the NRC authorizing the use of HDPE at Callaway for the ESW system.
According to technical people at Callaway, the bimodal HDPE resin from Dow provide exemplary corrosion resistance with performance and safety compared to the previously used steel pipes which corrode and form leaks before their expected life, thereby increasing cost effectiveness. Jimmy Zhou, Sr., Development Specialist for The Dow Chemical Company, says, "The distinct molecular architecture of this high performance resin contributes to longer extrapolated life expectancy, enhanced integrity and increased strength for pipes and fittings. CONTINUUM DGDA-2492 NT Bimodal Polyethylene Resin was developed using UNIPOL™ II process technology and designed for pipe applications.