CORDOVA  — Eight hours after a possible fire put the Cordova nuclear plant on alert, station officials announced that they were terminating the emergency status.

Workers at Exelon Nuclear's Quad-Cities Generating Station noticed smoke in a turbine building in Unit 2 at 1:40 p.m. Wednesday. Plant spokesman Bill Stoermer said on-site firefighters handled the possible electrical short "within seconds."

The alert was lifted at 9:32 p.m.

"There was no danger to the public whatsoever," Stoermer said.

Officials think the incident was limited to smoke, not fire. Some employees were evacuated from the unit, he said, and no one was injured. The plant is about 25 miles north of Moline.

The reactor had been taken offline Monday night to replace a valve on the control-rod drive system, and it was in the process of being brought back into service when the incident occurred Wednesday. It was safely shut down after the incident.

Viktoria Mitlyng, a spokeswoman for the Nuclear Regulatory Commission’s Region 3 headquarters in Lisle, Ill., said the alert was declared “due to there was smoke, maybe a small fire in the turbine building. It was not the reactor building.”

An alert is the second level in a four-level emergency declaration system, she said. The declaration stems from the fact that “some of the electrical equipment that provides power to the safety equipment … were no longer available because they were damaged.”

As a result of the alert, the NRC opened its Incident Response Center in Lisle, staffed by NRC electrical engineers, nuclear engineers and safety specialists. Also, NRC resident inspectors were monitoring the situation from the plant's control room.

Despite the apparent minor nature of the incident, firefighters from several nearby departments responded as a "purely precautionary" measure, Stoermer said.

The Illinois Emergency Management Agency also was on scene. Rock Island County Emergency Management has been alerted but "has not reached the level yet where the county would be involved," officials said.

“NRC staff will be engaged around the clock until the plant is ready to leave the alert,” Mitlyng said late Wednesday afternoon.

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She said the plant's Unit 1 was not affected and remained in operation, and no abnormal release of radioactive material resulted from the incident.

"Only one system was compromised," she said. "Even though there were other systems, the unit is not allowed to operate unless all the systems (are operating)."

She added that the electrical problem compromised some of the electrical system that provides power to the reactor's safety systems. "There are always multiple systems providing power," she said. 

The NRC will continue to monitor the events at the plant.

Restarting the plant, however, won't occur until an investigation is complete.

“We can’t start the plant back up until we know what the cause was,” Stoermer said.