I’m trying to play catch up after not posting anything in quite a length of time. I’ve decided to do a series of longitudinal reviews of the Nuclear Regulatory Commission’s Event Notification Reports for the last month covering a number of subjects, beginning with seismic warning capabilities. The nation’s nuclear power plants have been tasked with reviewing seismic monitoring capabilities in the aftermath of the Fukushima earthquake and tsunami. There were five items in the March reports.
1. On March 20, Illinois’ Byron nuclear power plant submitted a report titled Seismic monitor not available for Emergency Plan Assessment:
“…this notification reports a loss of Emergency Preparedness assessment capability with the unplanned inoperable condition for the Byron seismic monitor. Specifically, the seismic monitor was declared non-functional at 0345 CST on March 7, 2015 following an unplanned loss of the seismic monitoring central computer. This condition adversely impacted the capability to perform an ALERT EAL (HA4) assessment in accordance with the Radiological Emergency Plan Annex.”
In addition, plant operators reported:
“…Byron Station has identified six previous occurrences where the Seismic Monitor was declared non-functional, which impacted the capability to perform an ALERT EAL (HA4) assessment in accordance with the Radiological Emergency Plan Annex. These occurred on November 6, 2014; April17, 2013; January 2, 2013; October 10, 2012; July 18, 2012 and July 9, 2012.
2. On March 27, the LaSalle facility, also in Illinois, “identified 6 times in the past 3 years that the seismic monitor was inoperable such that emergency classification at the ALERT level could not be obtained with site instrumentation.”
3. Also on March 27, Illinois’ Quad Cities nuke reported that its review had found three occasions when “the seismograph was non-functional….”
4. On March 30, Braidwood (Illinois again) reported five instances when seismic monitoring equipment was not available.
5. And also on that day, Pennsylvania’s Three Mile Island reported out monitoring outage in the three year review.
Interesting fact: All five plants are operated by Exelon.