05000315/LER-2010-003

LER-2010-003, MICHIGAN One Cook Place
Bridgman, MI 49106 PIOWER® AE P.c om
A unit of American Electric Power
February 9, 2011 AEP-NRC-2011-7
10 CFR 50.73
Docket No. 50-315
U. S. Nuclear Regulatory Commission
Attn: Document Control Desk
Washington, DC 20555-0001
Donald C. Cook Nuclear Plant Unit 1
LICENSEE EVENT REPORT 315/2010-003-00
MANUAL AFW ACTUATION IN RESPONSE TO
MANUAL MFP TRIP
In accordance with the criteria established by 10 CFR 50.73, Licensee Event Report System, the
following report is being submitted:
LER 315/2010-003-00: "Manual AFW Actuation in response to manual MFP trip"
There are no commitments contained in this submittal.
Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at
(269) 466-2649.
Sincerely,
Joel P. Gebbie
Site Vice President
JEN/jmr
Attachment
c: INPO Records Center
J. T. King — MPSC, w/o attachment
S. M. Krawec — AEP Ft. Wayne, w/o attachment
MDNRE — WHMD/RPS, w/o attachment
NRC Resident Inspector
M. A. Satorius — NRC Region III
P. S. Tam — NRC Washington DC
12
NRC Form 366
U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES 08/31/2010
(9-2007) Estimated burden per response to comply with this mandatory collection request: 50 hours.
Reported lessons learned are incorporated into the licensing process and fed back to
industry. Send comments regarding burden estimate to the Records and FOIA/PrivacyLICENSEE EVENT REPORT (LER) Service Branch (T-5 F52), U.S.0Nuclear Regulatory Commission, Washington, DC 20555-
0001, or by Internet e-mail to infocollects@nrc.gov, and to the Desk Officer, Office of
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a person is not required to respond to, the information collection.
1. FACILITY NAME 2. DOCKET NUMBER 3. PAGE
Donald C. Cook Nuclear Plant, Unit 1 05000315 1 of 3
4. TITLE
Manual Auxiliary Feedwater Actuation in Response to Manual Main Feedpump Trip
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)

Docket Number
Event date:	1-3-2010
Report date:	02-09-2011
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation
Initial Reporting
ENS 46477	10 CFR 50.72(b)(3)(iv)(A), System Actuation
3152010003R00 - NRC Website

Conditions Prior to Event Mode 1, approximately 98 percent power

Description of Event

On December 13, 2010, at 2117 hours0.0245 days <br />0.588 hours <br />0.0035 weeks <br />8.055185e-4 months <br />, in response to decreasing condenser vacuum on the Unit 1 East Main Feedwater Pump (MFP) [SJ][P], Donald C. Cook Nuclear Plant (CNP) control room operators initiated the Rapid Power Reduction Procedure in an effort to quickly lower power to remove the East MFP from service. Within 2 minutes of initiating the power reduction, operators observed East MFP Condenser [SG][COND] vacuum rapidly' lowering toward the low vacuum trip setpoint. At 2119 hours0.0245 days <br />0.589 hours <br />0.0035 weeks <br />8.062795e-4 months <br />, they entered the procedure for Loss of One Main Feed Pump, manually tripped the East MFP and manually started both Motor Driven Auxiliary Feedwater (AFW) Pumps [BA] and the Turbine Driven AFW Pump as directed by the procedure. Power was lowered and stabilized at approximately 48 percent.

Cause of Event

The cause of the East MFP vacuum lowering was fouling of the MFP Condenser cooling water side due to debris intrusion from rough lake conditions. Corrective actions were taken to open and clean the lake cooling water side of the East and West MFP condensers.

Analysis of Event

Manually starting the Unit 1 AFW Pumps as part of a procedurally-directed action in response to the loss of one main feed pump is a conservative action to assure that feedwater is maintained to the unit's Steam Generators (SGs) [TB] when main feedwater flow has been significantly reduced while reducing reactor and turbine power. This action does not disable any equipment, nor does it adversely affect mitigation of any plant events. In the event a reactor trip was not avoided, the AFW Pumps were already operating, avoiding dependence on automatic actuation circuitry to provide AFW to the SGs. Thus, manually starting AFW Pumps reduces risk during this event where main feedwater flow was severely curtailed, by removing reliance on automatic actuation to start the AFW Pumps via the additional operator direction to start AFW Pumps "as required" based on operator judgment.

Corrective Actions

Completed Corrective Actions:

The East and West MFP condensers were both opened and cleaned.

Planned Corrective Actions:

None

Previous Similar Events

Licensee Event Reports (LER) for both CNP Unit 1 and Unit 2 for the past three years were reviewed for similar events related to 10 CFR 50.73(a)(2)(iv)(A) reporting criteria for system actuation. Plant design for CNP Unit 1 and Unit 2 has actuation of the AFW System as an expected response to reactor trips. The following were identified:

05000315-2010-002-00, Manual AFW Actuation in Response to MFP Failure On May 2, 2010, at 0855 hours0.0099 days <br />0.238 hours <br />0.00141 weeks <br />3.253275e-4 months <br />, a similar situation occurred in that the Unit 1 East MFP needed to be removed froth service very quickly due to failure of a bearing. All three AFW pumps were started when the MFP was required to be removed from service. Corrective actions from the bearing failure specifically addressed the bearing issue, so they could pot have prevented the situation resulting from the MFP condenser fouling.

05000316-2009-001-00, Unit 2 Manual Reactor Trip On July 26, 2009, at 1506 hours0.0174 days <br />0.418 hours <br />0.00249 weeks <br />5.73033e-4 months <br />, CNP Unit 2 control room operators performed a manual reactor trip in response to a malfunctioning reactor coolant pump (RCP) seal. AFW is designed to start in response to a reactor trip.

05000315-2008-006-01, Manual Reactor Trip due to Main Turbine High Vibrations On September 20, 2008, at 2005 hours0.0232 days <br />0.557 hours <br />0.00332 weeks <br />7.629025e-4 months <br />, CNP Unit 1 control room operators initiated a manual reactor trip from 100% power following Hi-Hi vibration alarms on all main turbine supervisory instrumentation vibration points. AFW is designed to start in response to a reactor trip.

05000315-2008-001-00, Unit 1 Manual Reactor Trip On February 2, 2008, at 0530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br />, CNP Unit 1 control room operators initiated a manual reactor trip from 93% power when main turbine bearing vibration reached the manual trip setpoint. AFW is designed to start in response to a reactor trip.

05000315-2007-001-00, Unit 1 Automatic Reactor Trip On August 28, 2007, at 1354 hours0.0157 days <br />0.376 hours <br />0.00224 weeks <br />5.15197e-4 months <br />, CNP Unit 1 received a reactor trip and main turbine trip signal as a result of low SG water level coincident with a steam flow — feedwater flow mismatch. AFW is designed to start in response to a reactor trip.