Ameren Missouri has dropped plans to build a second nuclear unit at its Callaway Energy Center, citing shaky economics in the context of cheaper renewables, low demand, and other factors for its decision.

“While we continue to believe nuclear power must be an important clean energy source for our company and country, as evidenced by the 20-year license extension we received this past March for our Callaway Energy Center, this loss provision was driven by recent changes in vendor support for licensing efforts at the Nuclear Regulatory Commission, our assessment of long-term capacity needs, declining cost of alternative generation technologies and the regulatory framework in Missouri among other things,” explained Ameren CEO Warner Baxter on July 31, during a second quarter 2015 earnings call.

The company submitted a combined license (COL) application in July 2008 to the Nuclear Regulatory Commission (NRC) for an AREVA EPR at its Callaway Energy Center near Jefferson City, Mo. The facility hosts a 1984-commissioned pressurized water reactor. In 2009, it informed the NRC of an announcement to suspend efforts to build the reactor but asked staff to continue reviewing the COL.

During the earnings call, Baxter noted that the company has been transitioning to a “cleaner, more diverse generation portfolio,” recently announcing plans for a new 13-MW solar facility west of St. Louis.

This February, Ameren issued a white paper suggesting “constructive and common-sense” changes to the proposed Clean Power Plan that would see the company retire more than a third of its coal fleet, add about 500 MW of renewables, and extend the license of its 1,200-MW Callaway Nuclear Energy Center, and add a 600-MW natural gas combined cycle unit.

On July 31, Baxter said that if the final Clean Power Plan required that Ameren alter and accelerate transition plans, “we fully expect that required investments will be treated fairly by our regulators.”

Sonal Patel, associate editor (@POWERmagazine, @sonalcpatel)