Event Notification Report for May 21, 2014

UNANALYZED CONDITION INVOLVING FIRE SAFE SHUTDOWN CAPABILITY

"This notification is to report a condition involving degraded control power wiring that resulted in an adverse impact on the ability to perform Fire Safe Shutdown for a postulated fire in the Main Control Room / Cable Spreading Room (MCR/CSR) complex. Therefore, this notification is being made pursuant to 10CFR 50.72(b)(3)(ii)(B).

"At approximately 1100 hours [EDT], based on inspections being performed as part of an extent-of-condition review, Engineering personnel concluded that a degradation existed involving transfer / isolation switches that potentially impacted the ability to mitigate an Appendix R fire postulated to occur in the MCR/CSR complex. During scheduled maintenance outage windows on March 6, 2014 and May 5, 2014, broken wires were identified and repaired while the associated systems were out of service. Based on completion of the extent of condition walkdowns today, an additional location was identified, raising the potential that this condition existed for a longer period of time. The wiring degradation is limited to the capability of using Shutdown Method 'D' as described in the Peach Bottom Atomic Power Station Fire Protection Program. Shutdown Methods 'A', 'B' and 'C' used for other postulated fire areas were not affected by this condition. The postulated fire would have had to cause the normal control power fuses to fail for the issue to impact the safe shutdown function.

"Compensatory measures have been established until the condition is corrected.

"The NRC Resident Inspector has been informed of this notification."

In the event of fire resulting in a loss of control power, compensatory measures will allow restoration of control power by replacing blown fuses. The compensatory measures are detailed in a temporary change to the MCR/CSR complex fire response procedure. The condition will be repaired during future equipment outages at the earliest opportunity.

STANDBY LIQUID CONTROL INOPERABLE DUE TO TANK INLEAKAGE

"On 5/21/2014 at 1721 CDT, BFN [Browns Ferry Nuclear] U2 declared both trains of standby liquid control (SLC) inoperable due to suspected in-leakage to the U2 SLC tank. Control Room Operators received an alarm for high tank level and corresponding high level on the control room indicator. Personnel were dispatched to check the tank level locally and reported that tank level was high and rising. Based on this report, the SLC tank isolation valve common to both pumps was closed to prevent potentially overflowing the tank. It was subsequently determined that the sensing line had become clogged causing erroneous level indication and the local report of level was incorrect. Sensing lines for the tank level instrumentation were subsequently cleared, indicated tank level then returned to normal, and local check verified that tank level was normal. Operability was restored with tank level being verified normal and isolation valve returned to the open position.

"This condition is being reported pursuant to 10 CFR 50.72(b)(3)(v)(C) and 10 CFR 50.72(b)(3)(v)(D). This is also reportable as a 60-day written report in accordance with 10 CFR 50.73(a)(2)(v)(C) and 10 CFR 50.73(a)(2)(v)(D).

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

CONTROL ROOM OVERHEAD ANNUNCIATOR MALFUNCTION

"At 0336 [CDT] on 5/21/14, during activities to isolate the preferred power supply for wiring modification, all control room annunciators cleared and lost power due to a disconnect switch failure associated with the alternate power supply. The normal power supply was restored at 0349 [CDT] to restore the annunciators to functional status. During the brief period of time the annunciators were unavailable, redundant assets as described in existing station documentation and/or the control room alarm typer remained functional along with the station computer alarms and Safety Parameter Display System to provide backup assessment capability.

"This event was previously determined to not be reportable, however, following additional review of the significance this is reportable. The NRC Resident has been notified of the event. The late reporting of this event has been entered into the Corrective Action Program."

The licensee notified the State of Ohio as well as Lucas and Ottawa counties.

AGREEMENT STATE REPORT - GAUGE SHUTTER FAILURE

The following report was received from the Commonwealth of Pennsylvania via facsimile:

"Notifications: The DEP [Pennsylvania Department of Environmental Protection and Bureau of Radiation Protection] Southwest Regional Office contacted the licensee upon our DEP Central Office receiving a reciprocity notification for a scheduled repair to be done on a level gauge with a stuck shutter. The RSO from the licensee was unaware that this shutter failure was a reportable event. This event is reportable within 24-hours per 10 CFR 30.50(b)(2).

"Event Description: The licensee made a service call to a service provider on May 21, 2014, for a quote on a stuck gauge shutter. This situation was discovered by the licensee during a shutter check and leak test. It is unclear if the shutter was stuck open or closed. However, the licensee does have a 'lock-out/tag-out' procedure, and personnel were restricted from the gauge area. It is also unknown at this time of the actual event date.

"Gauge Manufacturer: Ronan Engineering; Model: SA 1-F37; Serial Number: M7255; Source Isotope: Cesium-137; Activity: 10 millicuries (mCi).

"Cause of the Event: Unknown at this time.

"Actions: The Department plans to do a reactive inspection. More information will be provided when more information is received."

PA State Report #: PA140015