L-2014-013, Submittal of Technical Specification Special Report

Submittal of Technical Specification Special Report

ML14030A175
Person / Time
Site:	Saint Lucie
Issue date:	01/13/2014
From:	Katzman E Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2014-013
Download: ML14030A175 (3)

Text

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January 13, 2014 L-2014-013 10 CFR 50.36 U. S. Nuclear Regulatory Commission Attn:. Document,Control Desk Washington, DzC. 20555 R~ec,

• St. Lucie Unit 1 Docket No. 50-335

.,ate ofEvent'.December. !:5,:2013. .3 ...

Technical Specification Special Report The attached special report is being submitted pursuant to the requirements of St. Lucie Unit 1 Technical Specification 3.4.13, Action e, and Technical Specification 6.9.2. This report provides notification of an unplanned power operated relief valve (PORV) lift which mitigated a Reactor Coolant System (RCS) pressure transient that occurred on 12/15/13.

The St. Lucie Unit 1 RCS was restored to normal conditions following the event on 12/15/13.

Please contact us .Ithere&,ny quostions on this information.

Sincerely "

Eric S. Katzman,..

Licensing Manager St. Lucie Plant Attachment ESK/lrb Florida Power & Ught Company 6501 S. Ocean Drive, Jensen Beach, FL 34957

St. Lucie Unit 1 L-2014-013 Docket No. 50-335 Attachment Page 1 of 2 I TITLE Unplanned PORV Lift During St. Lucie Unit 1 RCS Pressure Transient II. EVENT DESCRIPTION On 12/15/13, at approximately 1000, St. Lucie Unit 1 was performing Reactor Coolant System (RCS) fill and vent (commonly referred to as pump sweeps) as part of a planned activity to restore the Reactor Coolant System following draining for a Reactor Coolant Pump (RCP) seal replacement on the 1A2 RCP. During the initial RCP start (1A1 RCP) to sweep any air in the RCS into the pressurizer and /or vessel head for venting, a sudden RCS pressure increase was observed from the initial RCS pressure of 310 psia over a very short period of time, resulting in the Power Operated Relief Valve (PORV) lifting with a setpoint of 350 psia. During the transient, actions were taken by operations to reduce RCS pressure and prevent exceeding 350 psia, including attempting to reduce pressure with the pressure controller and securing the running RCP and charging pump. The PORV lifted and reseated multiple times. RCS pressure was stabilized at 200 psia and shutdown cooling was restored, which had been previously secured for the evolution.

The Limiting Condition for Operation (LCO) 3.4.13, Action e states that:

"In the event either the PORVs or the RCS vent(s) are used to mitigate an RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days. The report shall describe the circumstances initiating the transient, the effect of the PORVs or RCS vent(s) on the transient, and any corrective action necessary to prevent recurrence."

III. CAUSE OF THE EVENT The PORV lift was due to the performance of the RCS fill and vent reactor coolant pump (RCP) sweep when the steam generator (SG) tubes U-Tubes had not been drained. RCS sweeps are performed to remove gas trapped in the SG U-tubes and relocate it to points in the RCS that can be vented, specifically the reactor head and pressurizer. Performing a plant startup without performing RCS sweeps is not common practice, since the SG tubes are typically either drained or remain pressurized during an outage. Since the RCS was not drained below the top of the hot legs during the outage, the SG U-tubes stayed filled and the RCS had fewer air voids than would normally occur during a refueling outage where the entire RCS is drained after defueling for maintenance. Consequently, upon RCP start the RCS pressure increased to the PORV lift setpoint.

'.V St. Lucie Unit 1 L-2014-013 Docket No. 50-335 Attachment Page 2 of 2 IV. ACTIONS TAKEN Short Term:

Secured from RCS Fill and Vent Procedure, restored RCS pressure to normal and placed Shutdown Cooling (SDC) in service 12/15/13.

Long Term:

A procedure change to the RCS fill and vent procedure will be made to require an assessment prior to performing RCS fill and vent RCP sweeps based on the RCS level not going below top of hot leg and RCS head venting, and will add a caution statement concerning the effects of not performing steam generator secondary side drain, fills and cooling. The Unit 2 procedure will be used as a reference for the changes, and the procedures will be aligned to be similar between the units for operator human performance factors. These actions will be tracked and documented in the site corrective action program.

V. SCHEDULE FOR RESTORING SYSTEM The St. Lucie Unit 1 RCS was restored to normal conditions following the event on 12/15/13.