An early morning computer failure triggered implementation of the Cook Nuclear Plant’s emergency plan for a couple of hours this morning, but it was never even close to being a threat to life and limb. Communications Manager Bill Schalk says the “Unusual Event” was quickly resolved and all proper authorities were notified.
Schalk tells us that Unit 1 at Indiana Michigan Power’s Cook Plant at Bridgman both “entered and exited its emergency plan at the lowest level” this morning following the failure of a computer that runs an alarm system for the control room.
An Unusual Event was declared at 3:10 a.m. when control room annunciators failed. The annunciator system monitors plant parameters and will alarm when the status of equipment or systems is outside pre-set limits. The system was restored in about three hours and the emergency plan was exited at 8:17 a.m.
An Unusual Event is the lowest of the four emergency classifications. It indicates a minor problem at the plant that varies from normal or routine operation. Federal, state and local authorities are notified.
The problem with the annunciators was determined to be a software issue with the computer controlling the annunciators. Both the primary and back-up systems were affected and subsequently restored when the systems were restarted.
Both units were at full power and remained stable during the activation. Even without the annunciators, operators can still monitor plant parameters and maintain safe operation. The issue has been resolved, and all systems have been returned to normal.