Various problems connected with the emergency operating facility (EOF) as well as a telephone network for the Omaha Public Power District (OPPD)’s Fort Calhoun nuclear plant have been reported to the Nuclear Regulatory Commission (NRC).
Both problems had been successfully addressed by 5:30 p.m. CDT on April 1, according to an event notification report filed with NRC. Power generation at the nuclear plant was not interrupted.
The transformer supplying power to the emergency facility stopped working due to the failure of a capacitor bank at about 12:10 p.m. on April 1, according the report filed with NRC.
The emergency facility located adjacent to OPPD’s North Omaha facility, about 17 miles south of the Fort Calhoun nuclear plant.
“The event caused a small grass fire which was quickly extinguished,” according to the report filed with NRC. “The local fire department was called. The backup emergency diesel generator for the EOF started and supplied power to the facility, as designed. With the EOF diesel operating, the facility is able to function as required during emergency conditions.”
Then at about 2:40 p.m. the EOF emergency diesel generator stopped running.
At 3:45 p.m., Conference Operations (COP) network phone system failed. The COP network is the primary emergency notification system between OPPD, state and county agencies. It is used to provide initial and updated notifications and for general information flow between these agencies.
“Alternate means of communication have been established (commercial lines) and a dedicated communicator is stationed in the control room to ensure that we can facilitate communication should the need arise,” according to the NRC report.
NRC announced March 30 that it is returning the roughly 500-MW Fort Calhoun pressurized water reactor (PWR) near Omaha, Neb., to its normal oversight program. The facility had been under NRC special oversight since Dec. 13, 2011. It returned to service in December 2013.
The NRC increased its oversight following a 2011 refueling outage that was extended due to record flooding, an electrical fire and significant performance issues.