Plastics

Houston - April 07, 2009

	Installation of DOW CONTINUUM™ DGDA-2492 Bimodal Polyethylene Resin to replace carbon steel at Calloway's nuclear power plant

The Dow Chemical Company today announced that AmerenUE's Callaway Nuclear Power Plant located near Fulton, Missouri has chosen DOW CONTINUUM™ DGDA-2492 BK Bimodal Polyethylene Resin to replace carbon steel in its buried essential service water (ESW) pipe system. 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 is 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.

"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," said Matthew Brandes, mechanical design engineer for AmerenUE at the Callaway Plant. "The selection of CONTINUUM bimodal resin for our ESW pipe system 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. Compared to steel piping systems, which are prone to internal corrosion, pitting and the formation of pin-hole leaks well before the end of their expected life span, high density polyethylene pipe does not corrode and provides an equal or greater level of performance and safety. With NRC approval of HDPE in buried portions of Callaway's ESW system, the HDPE has the potential to become the standard for buried ASME Class 3 and other nuclear power pipe systems."

"The success of CONTINUUM at Callaway is a significant milestone for PE 4710 bimodal polyethylene resin in nuclear power piping systems," said Jimmy Zhou, Sr., Development Specialist for The Dow Chemical Company. "The distinct molecular architecture of this high performance resin contributes to longer extrapolated life expectancy, enhanced integrity and increased strength for pipes and fittings.

Callaway found it particularly well suited for power plant applications such as ESW pipe systems, which require long-term hydrostatic strength, outstanding resistance to slow crack growth and excellent performance at elevated temperatures such as 176°F."

CONTINUUM DGDA-2492 NT Bimodal Polyethylene Resin was developed using UNIPOL™ II process technology and designed for pipe applications. Applications for CONTINUUM Bimodal Polyethylene Resins include natural gas distribution pipes, sewage pipes, municipal water service lines, industrial piping, and mining.

For more information about CONTINUUM DGDA-2492 BK 100 Bimodal Polyethylene Resin, please visit www.dowcontinuum.com.

About AmerenUE

AmerenUE is a subsidiary of St. Louis-based Ameren Corporation (NYSE: AEE). The Ameren companies serve 2.4 million electric customers and nearly one million natural gas customers in a 64,000-square-mile area of Missouri and Illinois.

About Dow

®™^* Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow

For Editorial Information:

Corey Newsom
The Dow Chemical Company
1-281-966-4245