The purchase of a portable eight-foot high dam for Exelon’s Dresden Gen-erating Station is one of a series of equipment and facility upgrades under way that are designed to protect the facility from extreme floods.
Three portable high-volume diesel water pumps, portable backup generators and other support equipment are on site. A 4,000-foot-long portable dam and other equipment are being delivered over the next few weeks to augment the nuclear facility’s flood protection strategy.
Exelon is reviewing other modifications to the plant that could be implemented as well.
“Maintaining safety at Dresden, even under the most severe circumstances, is our number one priority,” said Site Vice President Dave Czufin, the station’s senior executive.
“Over the past year and a half, we have invested thousands of hours to inspect and upgrade plant systems against natural events, especially flooding.
We have dedicated equipment, procedures and our operators are trained to safely shut down the station if we had an extreme flood, and we are adding new redundancies that give us even greater protection against such a natural disaster.”
The purchase of additional equipment was the result of industry lessons learned from the March 2011 earthquake and tsunami in Japan.
The equipment is being staged or installed to protect the plant in extreme floods beyond those previously anticipated.
Dresden sits at the confluence of the Des Plaines, Illinois and Kankakee rivers.
A comprehensive re-examination of Dresden’s flood protection strategy began immediately following the 2011 Japan events, where a tsunami flooded the seaside Fukushima-Daiichi nuclear facility.
Since then, all U.S. nuclear facilities have undergone extensive reviews of backup equipment, structures, procedures and emergency training needed to manage large-scale natural disasters.
The rivers near Dresden run at an elevation of 505 feet above sea level. The highest flood level ever recorded at the site was approximately 509 feet.
A 2003 Army Corps of Engineers study determined that a 500-year flood would crest at 511 feet at the site. Dresden’s site grade elevation is 517 feet — six feet above the predicted 500-year flood level.
The portable dam adds another 8 feet of flood protection margin and would keep water out of the station during an extreme flood higher than the site grade elevation.
If grid power needed to run emergency equipment were lost as a result of flooding in the area, Dresden has three locomotive-sized diesel generators, any one of which can supply sufficient power to operate safety equipment for an indefinite period. Those are backed up by two additional diesel generators.
Backing up the diesel generators are portable diesel-driven backup pumps and other equipment to fully protect the station.
Dresden Station will host a public community information event at the station on Saturday, Dec. 15, with station experts, equipment, and demonstrations regarding the plant’s flood protection strategy.
More information about the event will be forthcoming.
Dresden Generating Station is approximately 60 miles southwest of Chicago. The station’s two operating units can produce more than 1,700 megawatts net of electricity, enough to power nearly 2 million average homes.
Dresden Unit 1, which began commercial operation in 1960 and was retired in 1978, has been designated a Nuclear Historic Landmark by the American Nuclear Society.
