In 1969, Corn Belt Power Cooperative, Central Iowa Power Cooperative and Iowa Electric Light and Power Company, broke ground on the construction of a 550 MW capacity nuclear power plant - the Duane Arnold Energy Center (DAEC) near Palo, Iowa. At the time and ever since, Corn Belt Power has been a 10-percent stakeholder in the plant. Today, Iowa’s electric providers prepare for the imminent closure of the facility.
The construction on the nuclear power plant spanned several years, with commercial operation commencing in February 1975. It was the state of Iowa’s largest single construction project at the time.
The plant’s consistent and reliable operating strategy, along with $1 billion in additional investments over the years, led to a series of upgrades increasing DAEC’s capacity from 550 MW to 614 MW, today’s generating capacity. The plant’s successful operation was never on greater display than in 2008 when it survived the 500-year historic flood. Through thoughtful planning, the plant sits at 20 feet above the Cedar River, providing the protection needed from the flood. In 2008, with the river cresting at record levels, DAEC’s operation continued without faltering.
“The plant was an important generator for Corn Belt Power in the 80’s, 90’s and early 2000’s,” said Ken Kuyper, executive vice president and general manager, Corn Belt Power Cooperative. “For years it has been one of the best run nuclear facilities in the country. It has provided affordable and reliable power to Iowans for decades.”
Before Corn Belt Power joined Basin Electric Power Cooperative as a Class A member, Duane Arnold made up a large portion of energy supplied to members. Since joining Basin Electric, Corn Belt Power’s generation mix has diversified. Today, the co-op’s 10-percent stake or about 62 MW makes up only 1.6-percent of power supplied to members.
With increasing regulations on nuclear plants putting pressure on the cost of operations, and enhanced competition from lower cost natural gas-fired generation, in early 2018, NextEra Energy – the company that purchased Iowa Electric Light and Power’s (Alliant) 70 percent share of DAEC in 2005 - announced a likely end to production at DAEC in 2025 when Alliant Energy’s purchase power agreement (PPA) ended, despite having a license to operate through 2034.
Ultimately, NextEra Energy released Alliant Energy from the PPA early. NextEra Energy, as the majority owner, made another announcement in July 2018 that the plant would cease operations in October 2020.“
Having joined Basin Electric, we are well positioned to absorb the closure of DAEC,” Kuyper said. “It’s important to remember that we now rely on a vast amount of generators to supply power to Corn Belt Power members. Gone are the days of just having three or four resources. Today we have an all-of-the-above strategy, which makes our power supply more reliable and flexible in the future.”
Duane Arnold will cease operations later this year. It will take years before the area where the plant is located will return to green fields. Until that time, plant employees will still be monitoring and guarding the facility.