Event Notification Report for November 23, 2015

UNUSUAL EVENT DECLARED DUE TO REACTOR COOLANT SYSTEM LEAKAGE

"At 2148 EST on November 23, 2015, Salem Unit 2 declared an Unusual Event due to reactor coolant system leakage greater than 10 gallons per minute. While performing troubleshooting to determine the source of leakage from the Emergency Core Cooling System high head safety injection piping, a motor operated valve was opened and the high head piping relief valve lifted. Indications in the control room calculated the leak rate at 16 gallons per minute based on the change in Pressurizer level. The leak was terminated when the motor operated valve was closed and the relief valve reseated. The time [duration] of the leak was about one minute."

The licensee notified the NRC Resident Inspector.

Notified DHS SWO, FEMA Ops Center, and NICC Watch Officer. E-mailed FEMA NWC and Nuclear SSA.

* * * UPDATE AT 0105 EST ON 11/24/15 FROM BILLY MOWER TO JEFF HERRERA * * *

The licensee terminated the Unusual Event at 0100 EST on 11/24/15. The licensee will be cooling down and depressurizing to mode 5 in order to replace the affected valve.

The licensee will be notifying the NRC Resident Inspector as well as the New Jersey State police, Delaware State Police and local emergency dispatch.

Notified the R1DO (Dwyer), NRR EO (Morris), IRD MOC (Stapleton), DHS SWO, FEMA Ops enter, and NICC Watch Officer. E-mailed FEMA NWC and Nuclear SSA.

* * * UPDATE FROM JOHN OSBORNE TO JOHN SHOEMAKER AT 0341 EST ON 11/24/15 * * *

"This event is being reported in accordance with 10 CFR 50.72(b)(3)(v)(D). 'Any event of condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident,' due to inoperability of both trains of the Emergency Core Cooling System high head safety injection systems.

"The unusual event was exited at 0100 [EST] on November 24th, 2015, when the Emergency Core Cooling System high head safety injection piping inlet valves were closed, ensuring isolation of the relief valve. The criteria for exit was leakage rate was below the 10 GPM rate. The plant is in mode 3 cooling down to mode 5.

"The licensee notified the states of New Jersey and Delaware, Lower Alloways Township, and the NRC Resident Inspector."

Notified the R1DO (Dwyer).

MANUAL REACTOR TRIP AFTER PARTIAL MSIV CLOSURE

"At 0820 EST on 11/23/2015, Sequoyah Unit 1 was at 100% power when operators identified the Loop #3 Main Steam Isolation Valve (MSIV) came off its full open seat. This was evidenced by no OPEN indication on the main control board, dual indication on the post accident monitoring panel, and a change in both Tavg and steam pressure. Operators were dispatched locally to the MSIV and to the battery board room to investigate if a cause could be identified for the MSIV movement. The field investigation identified no issues. The operating crew manually tripped the reactor at 0844 EST due to an increasing Tavg-Tref mismatch.

"Following the reactor trip, all safety-related equipment operated as designed. Auxiliary Feedwater automatically initiated as expected from the feedwater isolation signal.

"Unit 1 is currently being maintained in Mode 3 at normal operating temperature and pressure, approximately 547 degrees F and 2235 psig, with auxiliary feedwater supplying the steam generators and decay heat removal via the condenser steam dumps.

"There is no indication of any primary to secondary leakage. All control rods fully inserted on the reactor trip and remain inserted. The electrical alignment is normal with shutdown power supplied from off-site power. There is no operational impact to Unit 2 as it continues through the refueling outage with the core off-loaded.

"There was no impact on public health and safety. Post-trip investigation is in progress and planned restart timeline has not yet been determined.

"The licensee notified the NRC Resident Inspector."

All control rods fully inserted during the reactor trip. The atmospheric steam dumps did operate during the transient and then shut. After the trip, the MSIV re-opened.

REACTOR SCRAM DUE TO A REACTOR RECIRCULATION PUMP LOCKOUT

"At 1040 CST, with the plant at 100% power, a lockout of the 11 recirculation pump occurred. Following the 11 recirculation pump lockout, at 1041 CST, a reactor scram and a Group 1 isolation occurred. All Main Steam Isolation Valves closed as a result of the Group 1 isolation signal. HPCI [High Pressure Core Injection] has been placed in service to control RPV [Reactor Pressure Vessel] pressure. HPCI did not inject into the RPV and was not needed to control RPV level.

"At 1104 CST, a Group 2 containment isolation signal was received due to RPV level less than +9 inches. The Group 2 isolation signal has been reset.

"The cause(s) of the 11 recirculation pump lockout, the reactor scram, and the Group 1 isolation are currently not known and are under investigation.

"This event is being reported under 50.72(b)(2)(iv)(B) due to the actuation of the Reactor Protection System when the reactor is critical.

"For the following reasons, this event is also being reported under 50.72(b)(3)(iv)(A):
1) This event resulted in a valid Group 2 containment isolation signal,
2) Since the cause of the Reactor Protection System actuation is not known, the event is being reported as a valid actuation of the Reactor Protection System, and
3) Since the cause of the Group 1 isolation is not known, the event is being reported as a valid primary containment isolation signal affecting multiple Main Steam Isolation Valves.

"All systems have responded as expected, all control rods fully inserted following the Reactor Protection System actuation. The plant is currently shutdown in mode 3, RPV pressure and RPV level are stable. This event did not result in any radiological release from the plant. This event did not challenge the health and safety of the public.

"The NRC Resident Inspector has been notified."

The plant is in its normal shutdown electrical lineup. HPCI is in pressure suppression mode with RHR cooling the suppression pool.

POSITIVE FITNESS-FOR-DUTY TEST

A non-licensed contract supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated.

The licensee notified the NRC Resident Inspector.