30 Mar (NucNet): High-density polyethylene (HDPE) will be used to replace carbon steel in underground essential service water (ESW) piping at a US nuclear power plant.
The Dow Chemical Company said its resin* had been selected by AmerenUE for use at the Callaway plant in the state of Missouri and would be the first use of polyethylene in a nuclear safety related application.
Dow said on 26 March 2009 that its ‘Continuum’ bimodal resin had been specified by the American Society for Testing and Materials (ASTM) as a PE 4710 material for use in 36-inch (91.4-centimetre) diameter pipe at the single-unit Callaway plant.
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 for buried portions of the Callaway ESW system and received a safety evaluation from the NRC authorising the use.
Matthew Brandes, the mechanical design engineer for AmerenUE at the Callaway plant, said: “AmerenUE is continuously looking for opportunities to take advantage of material and technological advances that will reduce operational costs and increase the safety and reliability of our systems.”
Mr Brandes said the selection of HDPE “enables a long-term, cost-effective solution to a challenge now facing all nuclear power utilities, namely the high costs associated with repair or replacement of buried piping systems”.
ESW pipes carry cooling water to the plant, where it is used for cooling of safety-classified equipment. Other systems provide cooling water to the main condenser in the powerhouse and not safety-classified systems.
In July 2008, AmerenUE submitted a combined construction and operating licence application to the NRC for a potential 1,600-megawatt advanced US Evolutionary Power Reactor next to the existing Callaway unit.
