August 2003

"Unusual Events" at Nuclear Power Plants: A Timeline

Moniak Research and Information Services -, Aiken, SC, 15 August 2003
By Don Moniak

[Posted 22/08/2003]

August 14, 2003 was an historic day for the nuclear power industry, as nine nuclear reactors at seven power plants in New York, Ohio, Michigan, and New Jersey were forced to shut down, and another NPP already in shut-down mode lost power during the largest and most severe electricity blackout in U.S. history. To date, a total of 9 NPPs and 11 reactors have reported significant impacts that generally rank as a low-level emergencies.

While the rest of the world described the blackout as a massive power failure, the Nuclear Regulatory Commission (NRC), in perhaps its most classic understatement to date, termed the widespread loss of power as "instabilities" in the electrical transmission grid, while assuring people that All plants are in a safe condition, using their emergency diesel generators where appropriate. (1)

The Commission elaborated on the issue today, stating that "Safety systems at all the shut-down plants operated successfully, and plants stabilized in a safe shut-down condition. Adequate safety was maintained at all times."

All seven plants issued an "unusual" event report, which the Commission described as "the lowest of four classes of emergency, and means an incident is in process or has occurred indicating a potential degradation of plant safety. No releases of radioactive material requiring off-site response or monitoring have occurred or are expected."

The Commission neglected to mention that had the unexpected occurred, and a full-blown higher-level emergency developed, the emergency sirens were not working at most plants--meaning that a safety system was not operating correctly. The Indian Point NPP in New York also suffered additional complications. This will not prevent the Commission from issuing glowering reports that the plants successfully prevented a major catastrophe--which in the nuclear industry is the primary standard for "safe" conditions.

Following is the timeline of events as published by the NRC in its "Event Notification Report for August 15, 2003." All times are Eastern Daylight Time, and indicate time of report, not of actual event--in general a 30-60 minute difference.

09:10 - The Kewaunee Nuclear Power Plant (NPP) in Wisconsin, which did not suffer any outages, did report that, "all 13 Kewaunee County sirens had a communications problem that rendered them out of service. The percent siren coverage population lost is 68.52%."

16:33 - The Perry NPP in Ohio declared an emergency unusual event, stating: "Automatic reactor scram due to a loss of offsite power. All [control] rods fully inserted. Supplying power to vital buses via emergency diesel generators. All system operating properly."

16:39 to 16:50 - The infamous Indian Point NPP in New York reported its two reactors having suffered an "Automatic reactor scram due to a loss of offsite power. All rods fully inserted. Supplying power to vital buses via emergency diesel generators. All systems operating properly." The event was later updated, with a declaration that "RPS Actuation (loss of flow) due to loss of site power. Auto actuation of AFW in response to the unit trips. Auto Start and Load of Emergency diesel generators in response to the loss of off-site power."

16:46 - The Ginna NPP in Upstate New York reported an "Automatic reactor trip due to a loss of offsite power. All rods fully inserted into the core. All emergency systems operated as expected."

16:54 - Davis Besse NPP in Ohio, which is shut down due to numerous safety problems, (2) declared an unusual event due to loss of offsite power, stating "All systems operated as expected. Decay Heat pumps are available if needed."

17:10 - While it did not shut down, the Palisades NPP in Michigan reported that, "At 1607 EDT a significant electrical power grid disturbance occurred resulting in a momentary drop in voltage at the site, including both 2400 VAC safety busses 1C and 1D. The reduced voltage on the 2400VAC safety busses caused both emergency diesel generators to auto start, but not load. The plant is stable at pre-event conditions." So while plants that did lose power described "grid instability," the plant that did not lose power described a significant grid disturbance--a relatively strong set of words.

17:15 - The Nine-mile NPP, Reactor 1, in Upstate New York reported "Automatic reactor scram due to a loss of offsite power. All rods fully inserted into the core. All emergency core cooling systems are operating properly and the emergency diesel generators are operating properly."

17:17 - The FitzPatrick NPP in New York reported, "Automatic reactor scram due to a loss of offsite power. All rods fully inserted into the core. All emergency core cooling systems and the emergency diesel generators are operating properly."

17:34 - The Nine-mile NPP, Reactor 2, in Upstate New York reported, "The plant lost off site power due to grid disturbance which resulted in a reactor trip from 100% power. The NOUE was declared because of loss of off site power was greater than 15 minutes."

18:16 - The Oyster Creek NPP in New Jersey reported a "Reactor scram from 100% due to off site electrical grid instability, but did not lose off site power. Reactor conditions at 1730 are normal reactor water level, reactor pressure 850-1000psig, MSIV's closed and all recirc pumps are off and reactor is in hot shutdown with all rods inserted."

18:49 - Indian Point NPP reported that "Emergency sirens lost in four counties due to a loss of power. At approximately 1830 hours power starting to be returned to the sirens."

20:07 - Ginna NPP updated its situation, stating that it "Received grid disturbance that caused reactor trip at 1611. The trip occurred due to over temperature delta set point being reached from load swings experienced on the generator. Subsequently in the recovery process, the Auxiliary Feedwater Pumps auto started from a signal from the Main Feedwater Pumps being secured. As a result of grid problems it was noted that Ginna did not meet the required number of emergency sirens (greater than 25% of sirens without

20:08 - The Fermi NPP in Michigan reported, "The reactor scrammed from 100% power due to fluctuations occurring on the main generator and a loss of off site power. All rods fully inserted and all MSIV's closed. Reactor level is being maintained in the normal band of 173 to 214 inches using RCIC. Reactor pressure is being controlled via SRV's in lo-lo set mode between 905 and 1017 psig. Isolations occurred as expected for level 2 and level 3. HPCI and RCIC started on level 2 signal."

21:08 - Ginna NPP "exited" the unusual event condition after restoration of off-site power.

23:40 - More problems emerged at Indian Point NPP Unit 3, which reported, "RPS Actuation (loss of flow) due to loss of offsite power. Auto actuation of AFW in response to the unit trips. Auto start & load of Emergency Diesel Generators in response to the loss of offsite power. Unit 3 also experienced a second AFW auto start during the event. Unit 3 also entered Tech Spec LCO 3.0.3 for loss of two offsite circuits and one EDG inoperable. #31 EDG was declared inoperable when its associated Fuel oil storage tank inventory decreased below required."

August 15, 2003

00:35 - Fitzpatrick NPP reported that, "Reactor vessel pressure is 93 psig. Plant electrical loads have been shifted back to offsite power and the EDGs were secured. The licensee exited the Unusual Event at 0039. The licensee tentatively plans to remain shutdown for a brief period to do some maintenance work."

01:45 - Nine Mile NPP units "exited" unusual event status when power was restored.

02:10 - Indian Point "exited" the unusual event "upon confirmation of a stable off-site power."

09:00: The NRC reported that "offsite power was restored to FitzPatrick, Ginna, Indian Point 2 and 3, and Nine Mile Point 1 and 2, and they exited the unusual event. The remaining plants [Perry, Davis-Besse, and Fermi, the Michigan and Ohio plants] continue to have onsite backup power." (3) No indication has been provided as to why Fermi reported the problem nearly four hours after the actual event.

11:00 - The NRC reported "no schedules have been established for restart of the affected nuclear power plants." The NRC's daily NPP status report showed all ten reactors

14:00 - Ditto. Perry, Davis-Besse, and Fermi still lacking off-site power supplies. (4)

Twelve non-nuclear power plants also shut down during the blackout, but unlike the nuclear plants these did not threaten regional populations and lanscapes with massive radiation exposure IF things had gotten worse. The NRC also failed to identify the current status of the non-nuclear plants.

Another information ommission is the impact the grid failure had on other northeast NPPs, as well as Canadian NPPs whose failures would greatly impact U.S. soil. The blackout included parts of New Jersey, Connecticut, Massachusetts, Pennsylvania, Ohio, Michigan, Vermont, Maryland, and the Canadian provinces of Ontario and Quebec.

No operational NPPs in Connecticut (Millstone 2 and 3) , Massachusetts (Pilgrim 1), Maryland (Calvert Cliffs 1, 2), Pennsylvania (Beaver Valley 1, 2; Limerick 1, 2; Peach Bottom 2, 3; Susquehanna 1, 2; and Three-Mile Island 1), New Hampshire (Seabrook 1), and Vermont (Vermont Yankee 1) reported any unusual events to the NRC. In addition, the D.C. Cook (Units 1,2) in Michigan; Hope Creek 1 and Salem Units 1 and 2 in New Jersey did not report any events. However, this only means that if there were disturbances at these plants, they were not of sufficient severity or importance to meet the Commission's lax reporting threshold.


(1) NRC News Release. August 14, 2003.
The plants were:
Indian Point 2 and 3 (in New York)
Perry (in Ohio)
Fermi (in Michigan)
Ginna (in New York)
FitzPatrick (in New York)
Oyster Creek (in N.J.)
Nine Mile Point 1 and 2 (in New York)
Davis-Besse, Ohio. (already in shut down for "other reasons" see footnote 3)

(2) see:
for details.

(3) NRC News Release. August 15, 2003.

(4) NRC. Frequently Asked Questions About the Loss of the Electric Power Grid on August 14, 2003. August 15, 2003.

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