Event Notification Report for June 23, 2010

UNIT 3 EMERGENCY RESPONSE DATA SYSTEM DECLARED INOPERABLE

"The Unit 3 Emergency Response Data System (ERDS) communications link availability is questionable. Some of the data has failed to zero. The system engineer has reported that the historian is not collecting data. Declared U3 ERDS inoperable."

The licensee will inform the NRC Resident Inspector.

MANUAL REACTOR SCRAM FOLLOWING LOSS OF BOTH RECIRCULATION PUMPS

"Limerick Unit 1 was manually scrammed from 100% power on 6/23/10 at 2051 hours in accordance with plant procedure OT-112 'Recirculation Pump Trip' when both 1A and 1B recirc pump MG set drive motor breakers were observed to have tripped, resulting in a loss of both reactor recirculation pumps. Preliminary indication is a loss of power to 114A Load Center, caused by 'A' phase overcurrent trip of 13.2 KV feeder breaker (11-BUS-07) to the 114A Transformer and Load Center. The cause of the MG set drive motor breaker trips is under investigation at this time.

"All Control Rods inserted as required.

"No ECCS or RCIC initiations occurred.

"No Primary or Secondary Containment Isolations were received.

"The plant is currently in Hot Shutdown maintaining normal reactor level with feedwater in service."

All systems functioned as required during the transient. The manual scram was characterized as uncomplicated. No PORVs or Safety Relief valves lifted during the transient. Decay heat is being discharged to the condenser via turbine bypass valves. The unit is in a normal shutdown electrical lineup and there was no impact on Unit 2.

The electrical supplies for the recirc pump MG sets has been walked down by the licensee and no indication of any damage or electrical faults has been found at this time.

The NRC Resident Inspector has been notified and the licensee indicated a media or press release will be made.

DECLARATION OF UNUSUAL EVENT DUE TO SEISMIC EVENT

"At 1428 [EDT] on Wednesday, June 23, 2010, an Unusual Event was declared for Unit 1 and Unit 2 based on Emergency Plan criterion N-1 'Natural or Destructive Phenomena Inside the Protected Area'.

"The Unusual Event was declared following detection of ground motion by persons on site, with confirmation based on United States Geological Survey information. Plant operation was not impacted by the event. Site structure and system inspections are in progress in accordance with the Abnormal Operating Procedure for Earthquake. No damage has been identified.

"In accordance with Emergency Plan procedures, notifications of Berrien County and State of Michigan were completed. The licensee has notified the NRC Senior Resident Inspector. A follow-up notification will be made after the Unusual Event is terminated.

"This notification is being made in accordance with 10 CPR 50.72 (a)(1)(i) due to declaration of an emergency class."

* * * UPDATE AT 1645 EDT ON 06/23/10 FROM JAMES SHAW TO S. SANDIN * * *

The licensee provided the following information as an update:

"A press release has been issued regarding the seismic event. This notification update is being made in accordance with 10 CFR 50.72 (b)(2)(xi) for news release or notification of other government agency."

The licensee informed state/local agencies and the NRC Resident Inspector. Notified R3DO (Lara).

* * * UPDATE AT 2017 EDT ON 6/23/2010 FROM TIMOTHY WICE TO MARK ABRAMOVITZ * * *

"The Unusual Event due to Seismic Event was terminated at 1955 EDT following an examination of plant systems which revealed no damage due to the seismic event. A press release has been issued regarding the termination of the Unusual Event. This notification update is being made to notify of the Unusual Event termination and also notify of the press release describing the Unusual Event termination in accordance with 10 CFR 50.72 (b)(2)(xi) for news release or notification of other government agency."

The licensee notified state/local agencies and the NRC Resident Inspector.

Notified the R3DO (Lara), NRR EO (Cunningham), DHS (Inzer), and FEMA (Hollis).

UNUSUAL EVENT DECLARED DUE TO AN EARTHQUAKE FELT ONSITE

"Event Description: An Unusual Event was declared at 1425 EDT due to reports from site personnel of an earthquake felt onsite. This was verified through the National Earthquake Information Center. Plant seismic monitors did not actuate.

"Actions Taken: Implemented OP 3127, Natural Phenomenon, for an earthquake. Plant personnel are walking down systems for any damage indications. [There is no indication of damage] at this time."

The licensee informed state/local agencies and the NRC Resident Inspector. The licensee plans to issue a press release.

* * * UPDATE AT 1742 ON 6/23/2010 FROM BOB VITA TO MARK ABRAMOVITZ * * *

The Unusual Event was terminated at 1725 EDT. Plant walkdowns were completed with no damage noted. The licensee notified the NRC Resident Inspector.

Notified the R1DO (Dwyer), NRR EO (Cunningham), DHS (Inzer), and FEMA (Hollis).

EARLY WARNING SIREN TEST FAILURE

"North Anna experienced a severe storm the night of June 22, 2010. At 0910 hours on June 23, 2010, the telecommunications group polled the Early Warning System (EWS) sirens to check operability. The first siren did not respond. It was determined the back-up base radio was not transmitting the audio signal to the sirens. Therefore, activation of the EWS by the state or local agencies would not have been possible. It was possible to activate the EWS sirens locally from North Anna off a separate radio system. At 1040 hours the back-up radio was replaced and tested satisfactory for proper radio function. The primary base radio was also replaced and tested satisfactorily. The polling function test was performed with all 68 sirens responding as designed. The EWS sirens are currently operating off of the primary base radio with the back-up radio available for operation."

The EWS was initially on the backup radio. This radio has been replaced.

The licensee notified the NRC Resident Inspector, state government and will notify local government. The licensee will contact local media concerning this event.

ALERT DECLARED FOR A CARDOX DISCHARGE IN THE TURBINE BUILDING

A CARDOX release occurred in the Unit-1 main turbine lube oil room and an Unusual Event was declared. The release resulted in an atmosphere immediately dangerous to life and health resulting in an Alert notification. No injuries resulted, however, the crane bay in the center of the turbine building was evacuated. Approximately 30% of the CARDOX storage tank was discharged due to a malfunctioning solenoid valve. This valve had recently been replaced.

The licensee notified the NRC Resident Inspector.

* * * UPDATE AT 1525 EDT ON 6/23/10 FROM TONY CHITWOOD TO S. SANDIN * * *

The licensee provided the following information as an update:

"On June 23, 2010, at 1035 PDT, an accidental discharge of CARDOX into Unit 1 Main Lube Oil Reservoir Room occurred during testing. On June 23, at 1048 PDT, an Unusual Event was declared for DCPP Unit 1. On June 23, at 1056 PDT, an Alert was declared for DCPP Unit 1. The DCPP Unit 1 reactor remains at full power. No safety related equipment has been impacted. There were no injuries to personnel and no equipment damage. Offsite assistance was requested to assist in event response.

"Pacific Gas and Electric Company issued the first press release at 1225 PDT on June 23, 2010. Further press releases will be issued as necessary until the event is terminated.

"The licensee notified the NRC Resident Inspector." The licensee also informed state and local agencies. Notified R4DO (Pick).

* * * UPDATE AT 2028 EDT ON 6/23/10 FROM DAVID EFRON TO S. SANDIN * * *

The licensee has terminated the Alert at 1715 PDT based on restoring accessibility to all plant area.

The licensee will inform state/local agencies, the NRC Resident Inspector and issue a follow-up press release.

Notified R4DO (Pick), NRR EO (Cunningham), IRD (Morris), DHS (Inzer), FEMA (Hollis), DOE (Yates), USDA (Petrick), and HHS (Lee).