05000247/LER-2009-004, For Indian Point 2, Regarding Loss of Single Train 23 Charging Pump Required for Remote Plant Shutdown from the Control Room Due to a Failure of a Pump Internal Check Valve
| ML092250375 | |
| Person / Time | |
|---|---|
| Site: | Indian Point  (DPR-026) |
| Issue date: | 08/07/2009 |
| From: | Joseph E Pollock Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-09-103 LER 09-004-00 | |
| Download: ML092250375 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor |
| 2472009004R00 - NRC Website | |
text
-Entergy 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-09-103 August 7, 2009 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop O-Pl-17 Washington, D.C. 20555-0001
SUBJECT:
Licensee Event Report # 2009-004-00, "Loss of Single Train 23 Charging Pump Required for Remote Plant Shutdown From the Control Room Due to a Failure of a Pump Internal Check Valve" Indian Point Unit No. 2 Docket No. 50-247 DPR-26
Dear Sir or Madam:
Pursuant to 10 CFR 50.73(a)(1), Entergy Nuclear Operations Inc. (ENO) hereby provides Licensee Event Report (LER) 2009-004-00. The attached LER identifies an event where the Technical Specification 3.3.4 Remote Shutdown safety function for single train 23 charging pump was inoperable thereby not available for remote shutdown from the control room, which is reportable as a safety system functional failure under 10 CFR 50.73(a)(2)(v)(A). This condition was recorded in the Entergy Corrective Action Program as Condition Report CR-IP2-2009-02376.
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 2 Mr. Paul Eddy, New York State Public Service Commission LEREvents @ inpo.org
Abstract
On June 23,
- 2009, the 23 Charging Pump was removed from service after operators observed decreased pressureizer level and degraded output flow.
The 21 charging pump was placed in service and the 23 Charging Pump was declared inoperable and Technical Specification (TS) 3.3.4 (Remote Shutdown) Condition A was entered. The 23 Charging Pump is a function specified in TS Basis Table 3.3.4-1 for reactor coolant system (RCS) inventory control.
The inoperable 23 Charging Pump resulted in failure to meet the specified safety function of TS 3.3.4.
The apparent cause of the degraded pump flow was a failure of one of ten internal check valves.
The cause of the valve failure was a random event.
This failure and previous failures were not confined to a specific location within the pump; are independent of service life; and independent of different specified valve materials.
Corrective actions included replacement of the failed internal check valve and remaining pump internal check valves.
The event had no significant effect on public health and safety.
(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
Past Similar Events A review was performed of the past three years of Licensee Event Reports (LERs) for events that involved inoperable remote shutdown functions.
One Unit 2 LER was identified, LER-2009-003.
LER-2009-003 reported a SSFF due to a loss of single train 21 Pressurizer Backup Heater required for remote shutdown from the Control Room caused by an inoperable breaker.
The inability to reset and re-close the breaker for the 21 pressurizer B/U heater was due to a misaligned control relay trip (anti-pump) lever.
LER-2009-003 had a different cause as the misaligned breaker lever was a result of a previous breaker rack-in whereas this LER was due to a failed component.
Unit 3 reported in LER-2008-002 a loss of the single train 31 pressurizer heater.
The unit 3 event was a different'cause as that event was due to a failed pressurizer heater transformer.
Safety Significance
This event had no significant effect on the health and safety of the public.
There were no actual safety consequences for the event because there were no accidents or transients requiring shutdown outside the CR.
If needed, a 45 gpm orifice can be put into service in lieu of the 75 gpm orifice which would reduce demand to approximately 54 gpm.
With the 23 Charging Pump at approximately 80 percent capacity, the use of the 45 gpm orifice would be sufficient to maintain RCS inventory with the degraded 23 Charging Pump.
Shutdown outside the CR could also be accomplished with the 21 Charging Pump.
Procedural guidance is available for operators to use the 21 Charging Pump (2-AOP-SSD-I, "Control Room Inaccessibility Safe Shutdown Control").
This procedure allows at Shift Manager discretion the use of the 23 or the 21 Charging Pump depending on plant conditions.
The 21 Charging Pump is capable of performing the same reactor coolant inventory control as the 23 Charging Pump.
Additionally, procedure SOP-ESP-I is available for starting the 21 Charging Pump at the 480 Volt Switchgear and local capability is available for adjustment of pump speed to maintain RCS inventory.
In accordance with NUREG-0800, Section 7.4, shutdown remote from the CR is not an event analyzed in the USFAR for accident analysis (Chapter 14).
Specific scenarios are not specified on which the adequacy of shutdown capability remote from the CR is evaluated.
A recognized type of event that could force the evacuation of the CR and the need to shut down remote from the CR is smoke from a fire.
Fire damage limits as they impact safe shutdown do not require consideration of an additional random single failure in the capability to safely shut down.
Therefore, application of single failure to remote shutdown is applicable only to other events that could cause the CR to become uninhabitable.
These events would not result in consequential damage or unavailability of systems required for safe shutdown.