A widespread power outage in Florida occurred just after 1 PM Eastern today affecting several millions of Florida customers. Two of Florida's five nuclear reactors were shutdown as a result of the outage. Here is a statement from the Nuclear Regulatory Commission:
At approximately 1:09 p.m. today, Turkey Point's two nuclear reactors (units 3 and 4) automatically shut down from 100% power in response to an "undervoltage" caused when two power distribution lines between Miami and Daytona went down following an equipment malfunction in a substation near Miami. The automatic trip of the reactors is a safety measure to protect plant equipment from abnormal power line voltages. The reactors are likely to be shut down for 12 to 24 hours, as part of a regular re-start protocol, with offsite power sources remaining available. Emergency diesel generators were not necessary.Here is the Nuclear Energy Institute's statement on the outage:
As the result of a disturbance in off-site power that led to an electricity outage throughout much of Florida, the two reactors at the Turkey Point power station in south Florida safely shut down earlier today. They were among several power plants, including fossil-fired power plants, that shut down today. The Nuclear Energy Institute’s executive vice president, Marvin Fertel, made the following remarks about nuclear power plant operations and design relative to this event.
“Nuclear power plants are designed to shut down safely in response to electrical grid disturbances. They have been required to do so on many occasions over the years, most notably during the August 2003 blackout that afflicted the Northeast and Midwest regions of the United States.
“As required by the Nuclear Regulatory Commission, nuclear power plants have on-site emergency backup power supplies available that enable them to be maintained in a safe condition if sufficient off-site power is not available. Backup power typically is provided by diesel generators, and more than sufficient fuel supplies for the generators are present on-site as well.
“Once the electricity grid is functioning and ready to be re-energized, power plant operators will follow precise procedures designed to ensure the safe restart of the Turkey Point power station’s two reactors to return electricity to the distribution grid. The start-up process typically takes approximately five hours if the power plant is in a ‘stand-by’ rather than a ‘shutdown’ mode. Start-up times for affected nuclear plants will vary depending on circumstances at each facility.
“Nuclear power plants’ electronic security systems also have independent back-up power to keep them functioning. Beyond that, nuclear power plants are protected by a paramilitary security force of highly trained, well-armed officers. Power plants also are protected by a combination of robust structural plant designs and redundant physical barriers.
“Specific questions concerning this power outage are properly addressed to the energy companies operating in Florida.”