Event Notification Report for September 17, 2015

VALID ACTUATION OF UV RELAYS FOLLOWING LOSS OF UNIT 2 STARTUP TRANSFORMER

"On September 17, 2015, at 1222 hours, with Unit 2 in Mode 5 at the beginning of a refueling outage, an electrical fault on the 2A 6.9 kV bus resulted in the loss of the 2A startup transformer and its associated non-safety related 2A2 and safety related 2A3 busses. At the time of the event, the 2A Emergency Diesel Generator (EDG) had been properly removed from service for scheduled maintenance. The loss of the 2A start up transformer initiated the under voltage relays, which resulted in a valid actuation signal that would have started the 2A EDG.

"Additionally, the 2A train of shutdown cooling (SDC) was de-energized; the 2B (protected) train of SDC was not affected by the event and remained in service to remove decay heat. The 2A shutdown cooling train was restored and made available on September 19, 2015 at 0030. The 2B EDG and 2B startup transformer remained operable.

"St. Lucie did not report this event within 8 hours of occurrence, however, this event was subsequently determined to be reportable pursuant to 10CFR50.72(b )(3)(iv)(A).

"During this event, Unit 1 experienced a loss of the 1A startup transformer. There was no effect on Unit 1 operation, as its associated non-safety and safety-related busses remained powered by the auxiliary transformer. The 1A startup transformer returned to service on September 18, 2015 at 2103."

The licensee informed the NRC Resident Inspector.

CONTROL ROOM AREA RADIATION MONITORS NOT ABLE TO PROVIDE RADIATION LEVEL INFORMATION

"On 9/17/2015 at 0030 [CDT], during the Byron Station Unit 1 refueling outage, Main Control Room area radiation monitors were removed from service to support an electrical bus outage. During this time, the Main Control Room area radiation monitors were not able to generate Main Control Room annunciation or provide area radiation level information necessary for Emergency Action Level (EAL) threshold determination until the area radiation monitor is restored which is scheduled for 9/20/15.

"This event is being reported under 10 CFR 50.72(b)(3)(xiii) for 'Any event that results in a major loss of emergency assessment capability, offsite response capability, or offsite communications capability.'

"The licensee has notified the NRC Resident Inspector."

The licensee discovered this issue at 2145 CDT on 9/19/15. The licensee established compensatory measures upon discovery of the issue.

BRIEF LOSS OF SECONDARY CONTAINMENT DUE TO BOTH AIRLOCK DOORS OPEN SIMULTANEOUSLY

"At 1220 (EDT) on 9/17/2015, both doors of a Secondary Containment airlock were reported to be simultaneously open for approximately five seconds during the normal passage of personnel. The brief time that the doors were simultaneously open constitutes an inoperable condition of Secondary Containment. Secondary Containment differential pressure was maintained throughout the time period that the doors were open.

"This event is being reported under 10 CFR 50.72(b)(3)(v)(C) and per the guidance of NUREG-1022, Rev. 3, 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.'

"The NRC Resident Inspector has been notified."

MINIATURE ALCOHOL BOTTLE DISCOVERED INSIDE THE PROTECTED AREA

"A miniature alcohol bottle, containing trace amounts of liquid, was discovered inside the protected area. Site security took possession of the bottle and removed it from the protected area."

The licensee notified the NRC Resident Inspector.

AGREEMENT STATE REPORT - RADIOGRAPHY CAMERA SOURCE DISCONNECT

The following information was received from the State of Texas via email:

"On September 18, 2015, the Agency [Texas Department of State Health Services] was informed by the licensee's radiation safety officer (RSO) that a radiography crew had experienced a source disconnect at a temporary field site [Galveston, Texas]. The RSO stated the crew was working inside a vessel using a QSA 880D exposure device containing a 52.9 curie Iridium-192 source. The device fell from a distance of 30 feet and hit the floor of the vessel. The source was in the fully shielded position when the device fell. The radiographers noted the guide tube had a small kink in it and replaced the guide tube. The radiographers tested the source by cranking the source out, but when they attempted to retract the source, the drive cable did not stop at the rear outlet of the camera. The radiographers contacted their supervisor and performed a dose rate survey at their barrier. The dose rate was 1 millirem per hour. An individual qualified in source recovery was able to remove the source from the guide tube and place it in a source changer for storage. The RSO stated their inspection of the source drive cable found the connecter on the drive cable had separated from the drive cable. The RSO stated all equipment involved in the event will be returned to the manufacturer for inspection. No individual received an over exposure as a result of this event. No member of the general public received an exposure due to this event. The licensee is conducting an investigation into the event. Additional information will be provided as it is received in accordance with SA-300."

Texas Incident: I-9339