DAEC operator will get to bottom of siren mishap

The operators of Iowa's only nuclear power plant vowed to get to the bottom of a recent warning siren mix-up.  Last Friday, one out of 144 sirens in Linn and Benton Counties blared a bogus message about problems at the Duane Arnold Energy Center in Palo.  The warning message at that failed siren, in northeast Cedar Rapids,  was not triggered by operator accident.  Rather, the pre-recorded message was activated on its own for reasons unknown.

Many residents in Linn and Benton Counties who live near the siren system assume the outdoor warning system is there only for tornado and weather alerts.  But NextEra Energy, the operator of the Duane Arnold Energy Center, actually own the system.  It's a requirement for the federal license needed to run a nuclear power plant.  Each siren costs between $20,000 and $27,000.

Dean Curtland, DAEC Plant Manager, said technicians have removed the electronics from the siren that activated accidentally.  Power plant operators will ask the manufacturer for a full scale test to pinpoint why the error happened.

“These types of sirens are used throughout the country and we want to understand what was the failure mechanism.  So this siren will be taken down, sent back to the manufacturer and we'll be doing a very formal failure analysis,” Curtland said.

Curtland also said the way the system works, operators on duty Friday night in the DAEC control room had no idea any of the sirens were going off.  Plant operators actually don't trigger the system itself-that's the job of the Linn County Emergency Management office.

Emergencies at the nuclear plant are broken down into four different categories.  An unusual event or first stage alert only indicates a potential problem within the plant-but a problem that can be handled by plant personnel and requires no public action.  The outdoor warning system is not triggered for such events.  A site area emergency or general emergency will be declared only if there is a major problem with the plant's safety and security.  And rules require notification of state and local authorities with 15 minutes and activation of the outdoor warning system.

But Curtland said well before any emergency reached that point, the plant would notify the media to get critical information out to the public.

“Once we notify the state and county, the next thing we'd do is get the notifications to the media-because we want the public to understand what is going on with the power plant,” Curtland added.

Plant operators say all the sirens contain pre-recorded warnings that can be triggered along with the siren.  No one can remember another failure involving a bogus radiological warning.