Event Notification Report for March 18, 2017

ALERT DECLARED FOR INDICATIONS OF FIRE IN SAFETY RELATED SWITCHGEAR

"Alert declared at 1119 EDT 3/18/17 based on EAL H.A.2 - Fire or Explosion affecting plant safety systems. Fire alarms in the Unit 3 4kV switchgear rooms resulting in a loss of the 3A 4kV bus and trip of all three Reactor Coolant Pumps. The reactor tripped and was stabilized in Mode 3. No actual fire was observed. The 3A 4kV is deenergized. The 3B Reactor Coolant Pump was restarted for forced circulation. All other safety systems functioned as required. A refueling outage was scheduled to begin on 3/20/17."

All control rods fully inserted on the reactor trip. Decay heat is being removed using feedwater and steam generator atmospheric steam dumps. One person was injured with a minor burn and possible sprained ankle and was taken to a local hospital.

The licensee notified the NRC Resident Inspector.

Notified DHS SWO, DOE, FEMA, HHS, NICC, USDA, EPA, FDA (e-mail), NWC (e-mail), NNSA (e-mail), and NRCC SASC (e-mail).

* * * UPDATE AT 1426 EDT ON 3/18/2017 FROM DAN HAGARDY TO BETHANY CECERE * * *

"Unit 3 was determined by the Emergency Coordinator to be in a safe and stable condition, the Emergency Plan personnel at the Technical Support Center and Emergency Operations Facility were no longer required for support, the Operations Support Center was staffed for recovery efforts, and plant personnel were sufficient and capable for continuing mitigation efforts.

"Investigation of the fault on the 3A 4kV bus is ongoing.

"Based on the above conditions, the Alert was exited at 1420 hours [on 3/18/2017]."

The injured electrician was taken to an offsite hospital to treat minor burns and possible sprained ankle.

The licensee notified the NRC Resident Inspector.

Notified the R2DO (Ehrhardt), NRR EO (Miller and King), IRD MOC (Stapleton), DHS SWO, DOE, FEMA, HHS, NICC, USDA, EPA, FDA (e-mail), NWC (e-mail), NNSA (e-mail), and NRCC SASC (e-mail).

AGREEMENT STATE REPORT - STOLEN MOISTURE DENSITY GAUGE

The following was received from the state of Texas via email:

"On March 18, 2017, the Agency [Texas Department of State Health Services] was notified by the licensee that a Troxler model 3440 moisture density gauge, serial #64732, containing a 1.48 GBq (40 mCi) Am-Be source and a 0.3 GBq (8 mCi) Cs-137 source was stolen. The licensee stated a technician improperly took the gauge home and left it in the back of his pickup truck. The sources were locked and inside their case. The case was secured by two locking mechanisms, both were cut sometime during the night before 0615 [CDT]. Local law enforcement was notified. Additional information will be provided as it is received in accordance with SA-300."

Texas Incident #: I 9472

THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

REACTOR TRIP AND LOSS OF ABILITY FOR UNIT 4 TO SUPPLY POWER TO UNIT 3

"On 3/18/17 at 1107 [EDT], the Unit 3 reactor tripped as a result of the loss of the 3A 4kV bus. All three reactor coolant pumps (RCP) tripped and the 3B RCP was restarted for forced recirculation. The reactor is stable in Mode 3. The 3A 4kV bus remains deenergized until troubleshooting and repairs are complete. In addition, Technical Specification 3.8.1.1, Action C requires a four hour report for the concurrent inoperability of the Unit 4 startup transformer to Unit 3 via the 3A 4kV bus and the Unit 3 3A diesel generator.

"The NRC Senior Resident Inspector will be notified."

* * * UPDATE ON 3/18/2017 AT 1854 EDT FROM JAMES SPICHER TO BETHANY CECERE * * *

"Update to previous report (EN 52623) to include additional reporting criteria.

"On 3/18/17 at 1107 [EDT] the Unit 3 reactor tripped as a result of the loss of the 3A 4kV bus. The 3A Emergency Diesel Generator (EDG) started on the loss of power signal but did not load, as designed, due to the bus fault. The 3A EDG was manually stopped at 1332. The Auxiliary Feedwater (AFW) System also initiated as expected. AFW was stopped at 1135. The actuations of the 3A EDG and AFW are reportable in accordance with 10 CFR 50.72(b)(3)(iv)(A).

"A loss of safety function affecting Units 3 and 4 occurred due to the loss of the 3A high head safety injection (HHSI) pump because it could not be powered from the faulted 3A 4kV bus with both Unit 4 HHSI pumps earlier (0624) removed from service due to planned maintenance. This caused three of the four HHSI pumps to be inoperable. The four HHSI pumps are shared by both Units 3 and 4. The safety function is achieved by two of the four HHSI pumps. Both Unit 4 HHSI pumps were restored to operable status at 1336. The loss of safety function is reportable in accordance with 10 CFR 50.72(b)(3)(v)(D).

"The Unit 3 reactor is stable in Mode 3. The 3A 4kV bus remains deenergized until troubleshooting and repairs are complete. Unit 4 remains operating at 100% power."

The licensee will notify the NRC Resident Inspector.

Notified R2DO (Ehrhardt) and NRR EO (Miller).