Duane Arnold Energy Center

Surrounding population

The Nuclear Regulatory Commission defines two emergency planning zones around nuclear power plants: a plume exposure pathway zone with a radius of 10 miles (16 km), concerned primarily with exposure to, and inhalation of, airborne radioactive contamination, and an ingestion pathway zone of about 50 miles (80 km), concerned primarily with ingestion of food and liquid contaminated by radioactivity.

The 2010 U.S. population within 10 miles (16 km) of Duane Arnold was 107,880, an increase of 8.2 percent in a decade, according to an analysis of U.S. Census data for msnbc.com. The 2010 U.S. population within 50 miles (80 km) was 658,634, an increase of 7.1 percent since 2000. Cities within 50 miles include Cedar Rapids (10 miles to city center).

History

In the late 1960s, Iowa Electric Light & Power Co. (now Alliant Energy - West), Central Iowa Power Cooperative and Corn Belt Power Cooperative applied for a nuclear plant license with the Atomic Energy Commission (AEC). On June 17, 1970 a construction permit was granted and work began. The original plan was to complete construction in 40 months at an estimated cost of $250 million.

The energy center was named after Duane Arnold who grew up in Sanborn, Iowa. Arnold was educated at Grinnell College and went to work for Iowa Electric Light and Power Company in 1946. At the time of his death in 1983, at the age of 65, he was chairman of the board and CEO of that company, marrying along the way the previous chairman’s daughter, Henrietta. Arnold was very committed to nuclear energy despite the controversy surrounding that source of energy, and oversaw the construction and opening in 1974 of the plant that bears his name. “In my opinion, nuclear power is the most beneficial method of anything we could possibly do to provide energy to our customers in the future,” Mr. Arnold stated in a 1979 interview with the Des Moines Register, about a month after the Three Mile Island accident. Controversies did not end with Mr. Arnold’s death. His son and four daughters went to court to force Iowa Electric to continue payments of a deferred compensation plan that the company stopped after Henrietta’s death in 1986.

Construction was completed and the reactor reached initial criticality on March 23, 1974. The cost was $50 million over budget. Commercial operations began on February 1, 1975. The plant was licensed for 1,658 MWt. However, power operations were restricted to 1593MWt (about 535 MWe) until plant modifications were completed in 1985 to utilize the full licensed capacity.

In May 2000, the NRC granted a license transfer of the DAEC to Nuclear Management Company LLC (NMC). Ownership of the plant remained with Alliant, Central Iowa Power Cooperative and Corn Belt Power Cooperative, but NMC would manage the operation of the plant.

In 2001, a power uprate was approved by the NRC to 1,912 MWt. Scheduled outages since that time have added modifications to the plant that have allowed this power level to be sustained without restrictions or challenges to nuclear or industrial safety.

On 27 January 2006, FPL Energy (a subsidiary of FPL Group) closed the sale transaction of 70 percent ownership from Alliant Energy-Interstate Power and Light. FPL Energy (now NextEra Energy Resources) also took control of the operations of the plant from NMC.

DAEC remained online during the 2008 Iowa Flood, when other power plants along the Cedar shut down. Practice drills for radiological emergencies from the plant allowed the Linn County Emergency Management Agency to better respond to the flooding.

Relicensure

In December 2010, the Nuclear Regulatory Commission granted Duane Arnold a 20-year extension license lasting until 2034, taking the plant well beyond the life of its original 40-year operating permit.

Plant equipment

DAEC has a single GE BWR-4 reactor with a Mark I containment. Twenty-four forced-draft cooling towers utilize water from the Cedar River as a heat sink. Facilities exist to process all contaminated water onsite and the DAEC operates with a "zero release" policy to not discharge any contaminated water back to the Cedar River. Facilities exist on site for dry storage of spent fuel with capacity for the entire life of the plant (including license renewal).

This reactor is fueled by uranium.

Known problems

Duane Arnold's primary containment shell was undersized in the original design.. The "torus direct vent bypass system" retrofit was installed in all 18 Mark I reactors in the late 1980s and is operated by a butterfly valve at the operators' control, after a zero leakage rupture diaphragm breaks prior to reaching the primary containment max design pressure. In 2013, in response to the accident at the Mark I reactor in Fukushima, the Nuclear Regulatory Commision ordered Mark I owners to install controls to operate the valve even after the primary containment had been breached by molten core.

The reactor has been shut down in unplanned scrams eleven times since the year 2000, as indicated in NRC performance indicator reports.

Seismic risk

The Nuclear Regulatory Commission's estimate of the risk each year of an earthquake intense enough to cause core damage to the reactor at Duane Arnold was 1 in 31,250, according to an NRC study published in August 2010.

Community impact

DAEC employs hundreds of people in the Cedar Rapids area. Some of these workers are represented by the International Brotherhood of Electrical Workers, others by Security, Police and Fire Professionals of America.

Emergency warning towers are maintained by DAEC and provide a means for tornado warnings as well as plant emergencies. The Emergency Planning organization at DAEC works with local, county, and state officials to maintain an emergency plan. The emergency plan can be found in the front of area phonebooks. Drills are conducted on a regular basis in accordance with requirements from the Nuclear Regulatory Commission (NRC) and the Federal Emergency Management Agency (FEMA).

Tax revenues from DAEC amount to about 1% of the total revenues for Linn County, Iowa. Pleasant Creek Reservoir, a 410-acre (1.7 km²) lake, was developed by Alliant and the Iowa Conservation Commission to provide a recreation area and act as a source of cooling water during times of low flow in the Cedar River.

While the DAEC site covers 500 acres (2.0 km²), only a portion of that is used for power production. The remainder is leased to farmers for crop production or is left in its natural habitat.