Event Notification Report for March 17, 2014

MANUAL REACTOR SCRAM DUE TO STEAM LEAK IN LOW PRESSURE TURBINE LINE

"On 3/17/2014 at 0514 [CDT] the reactor was manually scrammed from approximately 41% core thermal power due to a steam leak in the turbine building. All control rods fully inserted and all systems actuated and operated as designed. All Main Steam Isolation Valves were manually shut. The Reactor Core Isolation Cooling System was manually initiated to assist in level control and pressure control. No safety relief valves actuated automatically. Manual cycling of safety relief valves and Reactor Core Isolation Cooling are being used to maintain reactor water level and pressure within normal bands. Group 2 and 3 RHR isolation signals were received; however no valve movement occurred since the affected valves are normally closed.

"This event is reportable under 10CFR50.72(b)(2)(iv)(B) for the reactor trip and 50.72(b)(3)(iv)(A) for the manual start of the reactor core isolation cooling system."

The licensee informed the NRC Resident Inspector.

SECONDARY CONTAINMENT AIRLOCK DOOR INTERLOCK MALFUNCTION

"At 0750 EDT on March 17, 2014, Operations determined that both the inner and outer secondary containment airlock doors, on the 20 foot elevation of the Unit 1 reactor building, had been simultaneously opened for approximately 10 seconds. This event occurred while an employee was exiting secondary containment immediately after another employee had previously entered. Upon recognition of the condition, the employees took action to secure both doors. The cause of this event was malfunction of the secondary containment airlock door interlock.

"This condition is being reported in accordance with 10CFR50.72(b)(3)(v)(C), event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material. With both doors open, Surveillance Requirement 3.6.4.1.3 of Technical Specification 3.6.4.1, Secondary Containment, was not met, rendering secondary containment inoperable. At the time at the time of the condition, Unit 1 was engaged in Operations with the Potential to Drain the Reactor Vessel (OPDRV) and was crediting Secondary Containment as Operable.

"This event did not result in any adverse impact to the health and safety of the public.

"The safety significance of this is minimal. Secondary containment was only inoperable for approximately 10 seconds. This event did not result in any adverse impact to the health and safety of the public.

"The door interlock investigation [is] in progress. Doorwatches with communications have been stationed on either side of the Unit 1 and Unit 2 20 foot reactor building air lock doors. All other secondary containment access doors on both Reactor Building have been controlled as emergency exit only. Installation of temporary video surveillance system [is] being pursued until long term corrective action can be established per the corrective action program.

"The NRC Senior Resident has been notified."

MILLSTONE STATION MAIN STEAM RADIATION MONITORS OUT OF SERVICE FOR MAINTENANCE

At 1025 EDT on 3/17/14, the Millstone Station main steam radiation monitors were removed from service for pre-planned maintenance. This resulted in a degradation in the ability to detect steam generator tube leakage. The main steam radiation monitors will be returned to service within 79 hours.

The licensee informed State/local agencies and the NRC Resident Inspector.

DISPLAYED METEOROLOGICAL DATA POTENTIALLY INACCURATE

"At 1418 EDT on 03/17/2014, it was determined the atmospheric stability classification data display on the plant process computer (PPC) could have been potentially inaccurate.

"In September 2012, implementation of a hardware and software modification to separate the meteorological tower computer from the PPC introduced a calculation error to the PPC software design that resulted in the PPC potentially displaying inaccurate stability class data. The ability to accurately perform dose assessment calculations could potentially be affected when using the stability class indication obtained from the PPC.

"The availability and accuracy of backup stability class data via the meteorological tower computer or from Weather Services International were not affected.

"Within 24 hours of discovery, the procedurally described alternatives for obtaining stability class data were implemented.

"Subsequently, the PPC stability class software calculation was corrected and the PPC stability class display restored for use.

"There was no impact to any emergency declaration because there were no actual emergencies from the time the modification was implemented until the error was corrected.

"The licensee has notified the NRC Resident Inspector."

LOSS OF EMERGENCY SIRENS

"At approximately 0737 (CDT) on March 17, 2014, Waterford 3 was informed that four emergency sirens were inoperable. One other siren had previously been determined to be inoperable on March 12, 2014. Subsequent review during preparation of this notification has identified an additional eight inoperable sirens, which brings the total number of inoperable sirens to thirteen. There are a total of seventy-three sirens distributed among two parishes (counties). The loss of these thirteen sirens for more than one hour is considered a major loss of offsite response capability and is reported pursuant to 10 CFR 50.72(b)(3)(xiii).

"The two affected parish Emergency Operations Centers were notified of the condition and it was confirmed that they will use the preplanned alternative method of Route Alerting for the affected areas until notified that repairs to the sirens have been completed.

"Waterford 3 is working to repair the sirens. There is no effect on the plant. This issue has been entered into the Waterford 3 Corrective Action Program and appropriate corrective actions will be developed.

"The NRC Resident Inspectors, local agencies, and the State of Louisiana were notified."

AUTOMATIC REACTOR TRIP DUE TO TURBINE TRIP INITIATED BY LOSS OF STATOR COOLING WATER

"Ft. Calhoun station automatically tripped due to a loss of turbine load. The turbine tripped due to loss of stator cooling water. Maintenance was in progress on the stator cooling system when inventory was lost and low pump discharge pressure caused an automatic turbine trip and reactor trip. All systems operated as expected. Ft. Calhoun station is shutdown and stable in mode 3 at this time."

All control rods fully inserted into the core and decay heat is being removed using the normal condenser steam dump system.

The licensee has notified the NRC Resident Inspector.

TECHNICAL SUPPORT CENTER HABITABILTY IMPACTED DUE TO LOSS OF AIR CONDITIONING

"At approximately 1018 EDT on March 17, 2014, during a check of facility equipment, the Technical Support Center (TSC) was found to be degraded due to the loss of the air conditioning (AC) system. Due to the loss of AC, TSC habitability is impacted.

"The emergency assessment function can be performed in the control room as addressed in emergency response procedures. This event is reported in accordance with 10 CFR 50.72(b)(3)(xiii).

"This condition is common to both units.

"Unrelated to this condition, Unit 3 is currently in the process of shutting down in preparation for a refueling outage.

"Unit 4 will remain Mode 1, 100% Power.

"The TSC AC system repairs are in progress."

The licensee has notified the NRC Resident Inspector.

* * * UPDATE AT 0359 EDT ON 3/18/14 FROM PELL TO SNYDER * * *

The TSC AC system has been repaired and restored to service. The licensee will notify the NRC Resident Inspector.

Notified R2DO (O'Donohue).