Event Notification Report for March 07, 2015

CONTAINMENT DECLARED INOPERABLE DUE TO CONTAINMENT FAN COIL LEAK

"At 1155 CST on March 7, 2015, a small cooling water leak was identified on the 21 Containment Fan Coil Unit east face u-bend on the north east corner bottom bundle. Unit 2 Containment was declared inoperable, which required entry into Technical Specifications (TS) LCO 3.6.1, Condition A, Containment inoperable, applicable in MODES 1, 2, 3, and 4. Immediate actions were taken to isolate the Fan Coil Unit within 1 hour from the initial identification of the leak. 21 Containment Fan Coil Unit was isolated, Containment was declared operable and TS 3.6.1 Condition A was exited at 1220 CST on 3/7/15.

"This condition is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.

"The plant remains in a safe condition and there was no effect to the health and safety of the public.

"The licensee has notified the NRC Resident Inspector."

LIMITING CONDITION FOR OPERATION NOT MET DUE TO EMERGENCY SUMP PUMP INOPERABLE

"On March 7, 2015, at 0830 EST, the NCNR (NIST Center for Neutron Research) discovered a probable violation of the Limiting Condition for Operations of the TR-5 Technical Specifications (TS), 3.3.2, Specification (1), while performing maintenance during the scheduled reactor shutdown period. This initial report is being made in accordance with TR-5 TS 6.7.2.d.

"The TS is as follows:
'TS 3.3.2 Emergency Core Cooling; Specification: The reactor shall not be operated unless: (1) The D2O (deuterium oxide) emergency core cooling system is operable, and (2) A source of makeup water to the D2O emergency cooling tank is available.'

"The discovery was made at 0830 EST on March 7, 2015, that the local disconnect switch for the emergency sump pump was in the disconnect position. The last time that it was verified operable was on July 2, 2014, when the annual surveillance of operability was performed. There was no maintenance performed on the emergency sump pump, nor is there any other known reason that the switch would have been placed in the disconnect position since July 2, 2014.

"After the discovery the sump pump disconnect switch was immediately placed in the connect position.

"The emergency core cooling system, in the event of loss of core coolant, provides sufficient D2O, to passively provide adequate coolant for ~ 2.5 hours to cool the fuel and protect against the release of fission products. That part of the emergency core cooling system was and remains operable and is not part of this violation.

"The emergency core cooling system employs one sump pump to return spilled coolant to the overhead storage tank. There is only enough D2O in the overhead storage tank to provide cooling for 2.5 hours on a once through basis. Because there is only one sump pump, it must be operational whenever the reactor is operational (TS 3.3.2 (1)). In the event that that pump fails or is inoperable and the D2O supply in the overhead storage tank is exhausted, domestic water or a suitable alternative would be used to furnish water for once through cooling (TS 3.3.2 (2)). A source of makeup water to the D2O emergency cooling tank was and remains available and is not part of this violation.

"The violation that is the subject of this report is that the sump pump was discovered inoperable and may have been inoperable since July 2, 2014, which includes periods of reactor operation. That is a violation of TS 3.3.2 (1)."

The licensee is conducting an investigation into this event.

SPECIFIED SYSTEM ACTUATION DUE TO LOSS OF ONE RESERVE STATION SERVICE OFFSITE POWER SOURCE

"On March 7, 2015, at 2140 CST, with the plant in Mode 5, Refueling, the RSS#2, one of two Reserve Station Service offsite power sources, de-energized. This loss of RSS#2 caused the de-energization of the Division 2 Safety Bus, which caused a valid start signal to the logic of the Division 2 Emergency Diesel Generator. No start occurred, however, due to the diesel being in the maintenance mode. Division 2 Standby Service Water, which was being run for system fill and vent as well as surveillance testing, also lost power.

"At the time RSS#2 was lost, the Division 2 Diesel generator and Division 2 Standby Service Water were inoperable for the Refuel Outage 18 Division 2 maintenance window.

"Division 1 systems and RSS#1 were not affected by the power loss and continued to operate normally. There were 5 control building dampers and 1 floor drain air operated valve that repositioned due to the loss of power.

"The cause of RSS#2 de-energization is still under investigation."

The licensee notified the NRC Resident Inspector.