Brownville, Neb. – Nebraska Public Power District’s (NPPD) Cooper Nuclear Station declared an “Unusual Event” Saturday at 7:10 a.m. as a result of an earthquake in Oklahoma.

Minor tremors were felt at the plant which required plant operators to declare the event.

There was no threat to the public or plant personnel, and the station continued to operate safely. Per procedure, station personnel increased monitoring of plant equipment. No damage to the plant or equipment was noted.

“All nuclear power plants are designed to withstand the historically worst-case scenarios for the regions where they are built,” said CNS Emergency Preparedness Manager Jim Stough. “Cooper Nuclear Station was designed and built to withstand earthquakes of this magnitude, and our team members are highly trained to respond to an array of events, including earthquakes. Our personnel and the plant’s monitoring and safety systems all responded exactly as intended.”

An “Unusual Event” is defined as unusual events, minor in nature, which have occurred or are in progress which indicate a potential degradation in the level of station safety. If placed on a scale of 1 to 4, with 1 being the least serious level of an emergency and 4 being the most serious level of an emergency, an Unusual Event would equal a 1.

Cooper Nuclear Station is located three miles southeast of Brownville near the Missouri River. It is owned and operated by the Nebraska Public Power District, with headquarters in Columbus.