Event Notification Report for April 21, 2011

FITNESS FOR DUTY REPORT INVOLVING A NON-LICENSED CONTRACTOR SUPERVISOR

A non-licensed contractor supervisor tested positive for alcohol during a follow-up fitness-for-duty test. The employee's access to the plant has been suspended. Contact the Headquarters Operations Officer for additional details.

The licensee notified the NRC Resident Inspector.

AGREEMENT STATE REPORT - MALFUNCTIONING GAUGE INVOLVING A CESIUM-137 SOURCE

"On April 21, 2011, at approximately 1530 CDT, a malfunction occurred when a repaired gauge was being installed on a process vessel at the licensee's facility. The device has two 2-curie Cesium-137 sources, each attached to a separate chain, that are lowered into place in the insertion tube via hand crank. When the first source was being lowered into the tube, the mechanism seized and the source could not be raised or lowered. The device was removed from the vessel, the chain was cut, and the source was pulled up and placed into shielded container. The device and two sources were transported back to the service company for repair.

"Gauge information: Thermo Scientific (TFS) model 5220. Device SN: B-36. Source SNs: MB-3946 and MB-3956."

Texas Incident: I-8837

OFFSITE NOTIFICATION DUE TO INADVERTENT SEWAGE DISCHARGE

"On [Thursday], 4/21/2011, at 1405 [EDT], Oconee Nuclear Station notified the South Carolina Department of Health and Environmental Control (SCDHEC) that sanitary sewage had been collected and inadvertently discharged without processing through the sanitary sewage system. The event was identified at 0730 [EDT] on 4/21/2011. The suspected cause is plumbing blockage. It is estimated that intermittent discharges over approximately three months resulted in a total discharge of approximately 4500 gallons. The Oconee NRC Senior Resident Inspector was notified. This event notification is being made pursuant to 10 CFR 50.72 (b)(2)(xi) due to notification of SCDHEC.

"Immediate corrective action was taken to isolate the affected portion of the sanitary sewage system.

"This event has no significance with respect to the health and safety of the public."

MANUAL REACTOR TRIP DUE TO CIRCULATING WATER PUMPS OUT OF SERVICE

"A manual trip of Salem Unit 1 was initiated due to a loss of circulating water pumps from heavy grassing at the circulating water intake. All rods fully inserted on the trip and all systems responded as designed with decay heat being removed via the steam dump system. All Auxiliary Feed Water (AFW) pumps auto started as expected on low steam generator levels from the trip.

"During a period of heavy grassing with one circulating water pump out of service for maintenance and another out of service for water box cleaning, a third circulating water pump's screen stopped and this circulating water pump was emergency tripped. When this circulating water pump was emergency tripped, the adjacent circulating water pump received a large intake of grass and automatically tripped.

"The abnormal operating procedure provides guidance to trip the plant if less than three circulating water pumps are in service and power is above P-10. At this point the manual reactor trip was initiated.

"The crew entered EOP-TRIP-1, appropriately transitioned to EOP-TRlP-2 and stabilized the plant at no load conditions.

"Salem Unit 1 is currently in mode 3. Reactor Coolant System temperature is 547F with pressure at 2235 psig. All ECCS and ESF Systems are available. Salem Unit 2 is currently defueled in a planned refueling outage and there is no impact to Salem Unit 2.

"No personnel injuries have occurred as a result of the trip.

"This event is reportable per 10CFR50.72(b)(3)(iv)(A) due to the auto start of the AFW pumps.

"This event is reportable per 10CFR50.72(b)(2)(iv)(B) due to the manual reactor trip."

The plant is aligned with a normal electrical line-up from offsite power sources.

The Licensee has notified the NRC Resident Inspector. The Licensee will notify Lower Alloways Creek Township and the States of New Jersey and Delaware.

* * * UPDATE FROM MATTHEW MOG TO VINCE KLCO ON 4/21/2011 AT 2241 EDT * * *

"During the post-trip data review for the manual reactor trip that occurred on April 21, 2011 at 1601 [EDT], 2 additional automatic Auxiliary Feedwater (AFW) pump start signals were identified. Operators were controlling AFW level to maintain steam generator levels within the band required by the emergency operating procedures. At approximately 1615 [EDT] the 13 steam generator level had cleared the low level setpoint but subsequently dipped below the low level setpoint at 1623 [EDT]. At approximately 1640 [EDT], the 14 steam generator had recovered above the low level setpoint and subsequently dipped below the low level setpoint. The Unit 1 reactor had been previously tripped at 1601 [EDT] and all AFW pumps had automatically started. The 13 turbine driven AFW pump was stopped at approximately 1625 [EDT]. The two motor driven AFW pumps continued to run throughout this event. Low level in one steam generator generates an automatic start of the motor driven AFW pumps and is reportable per 10CFR50.72(b)(3)(iv)(A)."

The licensee notified the NRC Resident Inspector and will notify Lower Alloways Creek Township and the States of New Jersey and Delaware.

Notified the R1DO (Cook).

POTENTIAL INADVERTANT ACTIVATION OF ONE EMERGENCY SIREN

"On April 20, 2011, several hours after a severe lightning storm in the early morning hours, RE Ginna Nuclear Power Plant received a report that a siren may have activated. There was no specific location provided in the report. A review of the siren computer history showed no indication of any siren activation during that time frame. During the daily silent test of the siren system, one siren was determined to have failed due to loss of its AC power.

"During an inspection of the siren on April 21, 2011, it was reported that the siren appeared to have been struck by lightning. A number of electronic components in the siren had to be replaced and as a result the technicians were unable to determine if the siren had activated. As such. there is a potential that the siren may have been the source of the initial report. The siren has been tested and returned to service.

"The NRC Resident Inspector was notified by the licensee."

The licensee notified the Public Utilities Commission and Wayne and Monroe Counties.

VIOLATION OF TECHNICAL SPECIFICATION 3.3.2.2, CORE PURGE BLOWER

During a committee review, it was determined that during reactor operations on 4/21/11, the core purge blower was inoperable for greater than 5 minutes with reactor power greater than 100 KW which was a violation of Technical Specification 3.3.2.2. The licensee notified their Project Manager who advised them to notify the NRC Operations Center.

INVALID PRIMARY CONTAINMENT ISOLATION SYSTEM ACTUATION DUE TO CONFLICTING WORK ACTIVITIES

"This event is reportable under 10 CFR 50.73(a)(2)(iv)(A) as an automatic actuation of general containment isolation signals affecting containment isolation valves in more than one system. This 60-day telephone notification is being made in accordance with 10 CFR 50.73(a)(1) for invalid actuations reported under 10 CFR 50.73(a)(2)(iv)(A). This actuation was invalid since it was caused by maintenance activities and not by any actual plant condition warranting containment isolation.

"On April 21, 2011, at 1310 hours, upon de-energization of the Reactor Protection System (RPS) Bus A for maintenance, an unexpected actuation of the Groups 3 and 4 outboard containment isolation valves occurred. Outboard isolations occurred in the reactor building drain and ventilation systems, and reactor closed cooling systems. Control room emergency ventilation and standby gas treatment systems also started. All systems functioned as designed, excluding those components that were already removed from service. Following the event, the RPS Bus A was re-energized and the plant was restored to normal operating condition for the current configuration per plant procedures.

"The subsequent investigation found that personnel involved with work planning and control did not recognize that de-energizing RPS Bus A would create a condition which completed the Nuclear Steam Supply Shutoff System outboard isolation logic. An associated relay for the second channel had been previously de-energized to support ongoing maintenance. The cause of allowing this conflicting work to occur was determined to be inadequate procedural guidance. Planned corrective actions will enhance procedures to identify logic impacts, conflicting equipment and recommended protection schemes.

"There were no actual safety consequences associated with this event since all affected equipment responded as designed. The NRC Resident Inspectors have been notified."