Event Notification Report for October 07, 2014

ULTRASONIC TESTING REVEAL DEGRADED CONDITION ON ONE CONTROL ROD DRIVE MECHANISM PENETRATION

"In accordance with 10 CFR 50.72(b)(3)(ii)(A), this notification reports a degraded condition on Byron Station Unit 2 that occurred on October 7, 2014, when it was determined that the results of planned ultrasonic testing (UT) examinations performed on one CRDM penetration of the reactor vessel head would not meet the applicable acceptance criteria. Byron Station Unit 2 is presently in day eight of a refueling outage. The examinations were
being performed to meet the requirements of 10 CFR 50.55a(g)(6)(ii)(D) and ASME Code Case N-729-1 to ensure the structural integrity of the reactor vessel head pressure boundary. The UT examinations continue for the remaining CRDM head penetrations. The repairs are currently being planned and will be completed prior to unit start-up.

"The NRC Resident Inspector has been notified of this condition."

INVALID SPECIFIED SYSTEM ACTUATION

"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of general containment isolation signals affecting containment isolation valves in more than one system.

"On October 7, 2014, at 2135 [CDT], while in a refueling outage with the reactor non-critical (Mode 5), work activities were in progress that included replacement of an excess flow check valve and execution of a Technical Specification Surveillance Procedure on the Automatic Depressurization System. Subsequent to valving in a level transmitter (LT), water levels in both the variable and reference legs of the LT were disturbed resulting in a Unit 1 full scram and Primary Containment Isolation System (PCIS) Groups 2, 3, 6, and 8 isolation signals due to receipt of an invalid low reactor water level signal. The PCIS Groups 2, 3, 6, and 8 isolations caused the initiation of Trains A, B, and C of the Standby Gas Treatment System and Control Room Emergency Ventilation Subsystem 'A'. The Reactor and Refuel Zone ventilation fans tripped and the secondary containment dampers isolated.

"Operations personnel responded to the PCIS initiation, ensured all equipment operated as designed, and placed affected systems back in service.

"Plant conditions which initiate PCIS Group 2 actuations are Reactor Vessel Low Water Level (Level 3) or High Drywell Pressure. The PCIS Group 3 actuations are initiated by Reactor Vessel Low Water Level (Level 3) or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level (Level 3), High Drywell Pressure, or Reactor Building Ventilation Exhaust High Radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level (Level 3) or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid.

"There were no safety consequences or impact to the health and safety of the public as a result of this event.

"This event was entered into the Corrective Action Program as Problem Evaluation Report 943038.

"The NRC Resident Inspector has been notified of this event."

INADVERTENT SIREN ACTUATION

"At approximately 1230 EDT on October 7, 2014, Seabrook Station was notified by Rockingham County Dispatch that an inadvertent activation of the Public Alert Notification System (PANS) sirens in Newtown, NH occurred at 1220 EDT. The activation was caused by an apparent human error during procedure review by a town of Newton employee. The sirens sounded, reset, and are functional. This event is being reported as it may generate media interest. No press release is planned at this time.

"The NRC Senior Resident Inspector and Region I have been notified."