05000286/LER-2009-007, Regarding Automatic Reactor Trip Due to a Turbine as a Result of Turbine Autostop Oil Actuation Caused by a Failed Autostop Oil Fitting

Regarding Automatic Reactor Trip Due to a Turbine as a Result of Turbine Autostop Oil Actuation Caused by a Failed Autostop Oil Fitting

ML093020114
Person / Time
Site:	Indian Point
Issue date:	10/21/2009
From:	Joseph E Pollock Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-09-133 LER 09-007-00
Download: ML093020114 (6)

LER-2009-007, Regarding Automatic Reactor Trip Due to a Turbine as a Result of Turbine Autostop Oil Actuation Caused by a Failed Autostop Oil Fitting

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation 10 CFR 50.73(a)(2)(iv)(A), System Actuation
2862009007R00 - NRC Website

text

.- En tergy Indian Point Energy Center 450 Broadway, GSB P.O. Box 249 Buchanan, N.Y. 10511-0249 Tel (914) 734-6700 J. E. Pollock Site Vice President NL-09-133 October 21, 2009 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop O-Pl-17 Washington, D.C. 20555-0001

SUBJECT:

Licensee Event Report # 2009-007-00, "Automatic Reactor Trip Due to a Turbine Trip As a Result of a Turbine Autostop Oil Actuation Caused by a Failed Autostop Oil Fitting" Indian Point Unit No. 3 Docket No. 50-286 DPR-64

Dear Sir or Madam:

Pursuant to 10 CFR 50.73(a)(1), Entergy Nuclear Operations Inc. (ENO) hereby provides Licensee Event Report (LER) 2009-007-00. The attached LER identifies an event where the reactor automatically tripped, which is reportable under 10 CFR 50.73(a)(2)(iv)(A).

As a result of the reactor tripthe Auxiliary Feedwater system was actuated which is also reportable under 10 CFR 50.73(a)(2)(iv)(A). This condition was recorded in the Entergy Corrective Action Program as Condition Report CR-IP3-2009-03592.

There are no new commitments identified in this letter. Should you have any questions regarding this submittal, please contact Mr. Robert Walpole, Manager, Licensing at (914) 734-6710.

Sincerely, JEP/cbr cc:

Mr. Samuel J Collins, Regional Administrator, NRC Region I NRC Resident Inspector's Office, Indian Point 3 Mr. Paul Eddy, New York State Public Service Commission LEREvents @ inpo.org

Abstract

On August 27,

2009, a Turbine Trip and Reactor Trip were initiated by main turbine control oil Autostop turbine trip.

All control rods fully inserted and-all required safety systems functioned properly.

The plant was stabilized in hot standby with decay heat being removed by the main condenser.

There was no radiation release.

No Emergency Diesel Generator actuated as offsite power remained available.

The Auxiliary Feedwater (AFW)

System automatically started as expected due to Steam Generator low level from shrink effect.

The cause of the trip was a loss of Turbine Autostop oil pressure below the trip setpoint due to a failed pipe adaptor fitting on the line connecting the Turbine Autostop oil to the Turbine solenoid trip device.

The pipe adaptor fitting failed due to high cyclic fatigue caused by the improper installation of the Autostop oil line fitting in the Turbine pedestal bulkhead wall.

The cause of the event was the as-found configuration did not meet the Original Equipment Manufacturer (OEM) design expectation.

This condition resulted in a configuration where the threaded fitting bottoms out in the threaded hole which induced additional stress on the fitting threads.

The additional stress combined with normal stress caused a premature failure.

Corrective actions

included replacement of the failed fitting, inspection of Autostop oil lines, and monitoring vibrations on turbine bearing No.

1. An engineering change will be developed to redesign the turbine pedestal piping wall penetration for the autostop oil turbine protection solenoid valve.

The event had no effect on public health and safety.

(If more space is required, use additional copies of (if more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)

For this event, rod controls were in Auto and all rods inserted upon initiation of the automatic RT.

The AFWS actuated and provided required FW flow to the SGs.

RCS pressure remained below the set point for pressurizer PORV or code safety valve operation and above the set point for automatic safety injection actuation.

Pressurizer level remained on scale.

Following the RT, the plant was stabilized in hot standby.