High water from Hurricane Sandy prompted an alert at Exelon's Oyster Creek nuclear plant Monday night, while one unit at Entergy's Indian Point shut down and a total of ten plants along the Eastern Seaboard were under the watch of additional inspectors from the Nuclear Regulatory Commission.At Oyster Creek on the New Jersey coast about 60 miles east of Philadelphia, the level of water in the plant's intake structure exceeded the regulatory levels requiring an unusual event declaration at about 7 p.m., followed by the alert at about 8:45 p.m. The plant's reactor was safely shut down for maintenance at the time. Wind, storm surge and a rising tide caused the high water levels that were expected to begin falling last night, according to the NRC. If water levels in the intake structure are high enough, they can threaten service water pumps.
Reuters quoted an Exelon representative as saying power had been disrupted at Oyster Creek, and that diesel generators were providing backup power to spent fuel cooling systems. Early this morning, the news agency also quoted an NRC spokesman as saying Constellation Energy's Nine Mile Point unit 1 had shut down, although it was unclear whether the shutdown was caused by conditions at the plant itself.
Earlier Monday, the NRC dispatched additional inspectors to all of the units potentially affected by the storm. Those included reactors at Oyster Creek, Salem, Hope Creek, Calvert Cliffs, Limerick, Peach Bottom, Three Mile Island, Susquehanna, Indian Point and Millstone.The Associated Press reported that one unit at Entergy's Indian Point north of New York City was shut down at about 10:45 p.m. because of external issues with the electrical grid. Earlier, the NRC had reported that, as of 9 p.m., Monday, no operating plants had experienced wind speeds or water levels that would require a precautionary shutdown.Dominion's Millstone 3 reactor in Connecticut was running at 75 percent power as a precaution against storm surge and to promote grid stability in the event it was shut down, The Day newspaper of New London, Conn., reported.PPL Corp.'s Susquehanna 2 reactor in Pennsylvania also was operating at 75 percent power Monday, according to the NRC, although it was uncertain whether its power level was related to the storm.In a release, The Canadian Nuclear Safety Commission said the recently refurbished Point Lepreau nuclear plant owned by New Brunswick Power was following severe weather emergency procedures, but no problems at the plant were reported as of midnight last night.
Entergy's Northeast Nuclear Plants Safely Weather Hurricane Sandy
With the brunt of Hurricane Sandy now past the eastern seaboard, Entergy's Indian Point Energy Center and James A. FitzPatrick Nuclear Power Plant in New York, Pilgrim Nuclear Power Station in Massachusetts and Vermont Yankee Nuclear Power Plant in Vermont have all safely weathered the storm.
Indian Point 2, FitzPatrick and Pilgrim remained at full power while Vermont Yankee reduced power to 88 percent at the request of ISO New England to help maintain grid stability. Indian Point 3 automatically shut down at 10:41 p.m. Monday as a result of an electrical grid disturbance.
"Nuclear plants are built to exceed the most severe natural forces historically reported for their geographic area," said John Herron, president and CEO of Entergy Nuclear. "And we saw evidence of that again with Hurricane Sandy."
Entergy Nuclear plants began preparations for the storm last week, coordinating activities with the Nuclear Regulatory Commission, the Federal Emergency Management Agency, independent system operators and various state and local government officials.
Critical Entergy Nuclear staff remained dedicated at each site, ready to respond to potential weather impacts.
In addition to the nuclear plant staff sequestered at Indian Point, FitzPatrick, Pilgrim and Vermont Yankee, the company's utilities in Arkansas, Louisiana, Mississippi and Texas sent more than 850 highly-experienced restoration workers and support personnel to the region impacted by the hurricane. They include scouts, who assess damage when safe to do so after the storm, and tool workers who will help rebuild the electrical system. Entergy will also provide some customer service representatives to remotely answer customer calls from affected areas.
SOURCE Entergy Corporation
More on Nine Mile Point from this morning's NRC event report:
"On October 29, 2012 at 2100 EDT, Nine Mile Point Unit 1 experienced an automatic reactor scram due to a generator load reject. The cause of the load reject is currently under investigation. All control rods fully inserted and all plant systems responded per design following the scram.
Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 2101 EDT, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. Three Electromatic Relief Valves actuated due to this scram and re-closed automatically.
Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. Decay heat is being removed via steam to the main condenser using bypass valves. Both Reserve Station Transformers are in service and being supplied by their normal power sources. Both Emergency Diesel Generators are operable and in standby.
The unit is currently implementing post scram recovery procedures."
At unit 2:
"On October 29, 2012 at 2100 EDT, Nine Mile Point Unit 2 experienced an automatic initiation of the Division 1 Emergency Diesel Generator due to a loss of line 5. Line 5 is one of the 115KV offsite power sources. Line 5 was lost due to a lightening arrestor falling onto electrical components in the Scriba switchyard during high winds.
"During the electrical transient, Nine Mile Point Unit 2 also experienced a feedwater level control lockup, requiring manual control. No Emergency Core Cooling Systems actuated and feedwater level control was returned to automatic. Nine Mile Point Unit 2 remained at 100% power during the loss of line 5.
"The off-site power source, line 5, was restored on October 30, 2012 at 0326 EDT."
Nuclear Street News Team
Unit 1 at Salem also tripped at about 1 a.m. From the NRC event report:
"MANUAL REACTOR TRIP FROM 100% POWER
This report if being made under the requirements of 10 CFR 50.72(b)(2)(iv)(B), Actuation of the Reactor Protection System While Critical, except preplanned, and under the requirements of 10 CFR 50.72(b)(3)(iv)(A), Valid Actuation of Listed System, except preplanned.
"Salem Unit 1 was operating at 100% reactor power when a loss of 4 condenser circulators required a manual reactor trip in accordance with station procedures. The cause of the 4 circulators being removed from service was due to a combination of high river level and detritus from Hurricane Sandy's transit.
"All control rods inserted. A subsequent loss of the 2 remaining circulators required transition of decay heat removal from condenser steam dumps to the 11-14 MS10s (atmospheric steam dump). Decay heat removal is from the 11/12 Aux Feed Pumps to all 4 steam generators via the 11-14 MS10s. 11/12/13 AFW pumps started due to low level on all steam generators due to shrink from full power operation (this is a normal response). All safety related equipment functioned as expected. No one has been injured. As an additional note, Hurricane Sandy had recently moved past artificial island. Salem Unit 1 is currently in Mode 3. Salem Unit 2 reactor is currently in its 2R19 refueling outage and is shutdown and defueled with no fuel movement in progress."