05000301/LER-2003-004

LER-2003-004,

Docket Number
Event date:	07-10-2003
Report date:	08-15-2003
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation
3012003004R00 - NRC Website

FACILITY NAME (1) � DOCKET NUMBER (2 � LER NUMBER cs-, � PAGE (3) Point Beach Nuclear Plant, Unit 2 � 05000301 �

Event Description:

aft experienced a trip of the 2P-2813 '13' main feedwater pump (MFP)'

• The MFP failure occurred at approximately 1340 (all times are CDT) when the MFP motor2 breaker' tripped instantaneously on overcurrent. The PBNP units are equipped with two 4160 vat motor driven MFP, each of which can provide steam generator; feed water for a nominal 50% of the plant capacity. Since the plant was operating at essentially 100% power at the time of the failure, the result was an automatic Unit 2 reactor trip at approximately1341. The trip was due to a feed flow/steam flow mismatch coincident with low steam generator level. The control room crew Initially entered abnormal operating procedures AOP-17A, `Rapid Load Reduction,' and AOP —2B, mFeedwater Malfunction.' Following the trip, the operating crew initially entered emergency operating procedure ECP-0, 'Reactor Trip or Safety injection,' followed by transition to EOP-0.1, 'Reactor Trip Response.' Following the unit trip, the reactor protection and safety systems responded as required and the unit was stabilized in Mode 3 at normal operating temperature and pressure. During the trip transient the auxiliary feedwater systems (AFWS) actuated as expected due to the Initial low steam generator water levels. The AFWS and other equipment necessary for response to this event performed as designed. An Event Notification System (ENS) telephone call (EN 39988) was made at 1455 to notify the NRC of the transient in accordance with 10 CFR 50.72(b)(2)(N)(B) for the RPS actuation (scram) and 50.72(b)(3)(iv)(A), specified system (AFWS) actuation.

Event Analysis:

An equipment root cause investigation was initiated to determine the reason for the main feed pump breaker trip and failure of the MFP motor. The initial results of this investigation are discussed in the "Cause' discussion which follows.

On July 11, 2003, the plant staff concluded that Unit 2 could be returned to operation with a single MFP and power limited to approximately 50% while the '13" MFP motor was being replaced. A reactor startup was started at 2006 on July 11, 2003. That startup was terminated when a cooling transient necessitated a manual safety injection and manual reactor trip. That event is being reported in a separate LER 301/2003-005-00, 'Manual Reactor Trip and Safety Injection Due to Pressurizer Low Level.* Following the resolution of the problems identified in these events, Unit 2 was taken critical at 2306 on July 12, 2003, with a nominal power limit of approximately 50% for single feed water pump operation. The Unit 2

• B" feedwater pump motor was subsequently replaced with the on-site spare motor.

PBNP Unit 2 returned to full power operation on July 16, 2003 at 0446.

Cause:

The apparent cause of the 2P-28B MFP motor failure has been preliminarily determined to be failure of the stator winding insulation due to age related degradation. Additional inspection and testing is planned for the vendor contracted to rewind the motor to determine the validity of this failure mode assessment.

Corrective Action:

The failed MFP motor was replaced with an on-site spare motor which had previously been rewound as part of its refurbishment. If additional corrective actions are identified following the vendor inspections and repair of the failed motor, they will be included in the PBNP corrective action program.

1 System Identifier SJ Component Identifier P 2 Component Identifier M 1 Component Identifier BK 4 Component identifier SG 1 Component Identifier RCT System Identifier BA FACILITY NAME (1) � DOCKET NUMBER (2) � I.ER NUMBER (6 � PAGEJ3) 2003 - 004 � 00 A

Safety Significance:

With the exception of the MFP motor equipment failure, which initiated this event, the plant response during and following this reactor trip and AFW actuation was as expected. Systems and equipment necessary to mitigate the consequences of this transient performed as designed and maintained the plant in a stable hot shutdown condition.

Other than a challenge to the reactor protection system and other plant equipment necessary to remove shutdown decay heat and maintain the plant in a stable configuration, the safety significance of this event was minimal. The safety and welfare of the public and the plant staff was not impacted by this event. During this event end the subsequent recovery actions there was at no time a loss of a system, structure, or component related safety functions; therefore, this event did not involve a Safety System Functional Failure.

Previous Similar Events:

A review of LERs submitted in the past three years identified the following events which involved a reactor trip due to equipment fault or failure:

LER NUMBER � ilia 301/2001-001-00 � Ground Fault Relay Actuation Causes Generator Lockout and Reactor Trip 301/2000-007-00 � Fault Associated with

• C" Phase Main Step-up Transformer Results In Reactor Scram 301/2000-006-00 � Failed Fuse in intermediate Range Nuclear Detector Results in Reactor Scram This report is provided in accordance with the PBNP Fire Protection Evaluation Report (FPER), Section 8.1.5. That section requires the submittal of a report to the U. S. Nuclear Regulatory Commission when degradation of fire protection systems or components exceeds the time listed in FPER Section 8.1.3. Paragraph C.1.b (4) of that section requires a report if an inoperable fire barrier is not restored to an operable status within a seven-day period. This letter is being provided to report four such conditions.

As part of a plant modification to install high energy line break barriers at the 46 foot elevation of the Point Beach Primary Auxiliary Building (PAB), several fire barrier penetrations have been breached to facilitate the installation of the modifications. Two penetrations, designated M-3-5- 16-W1 and M-3-5-16-W23, were removed from service on July 9, 2003. These penetrations were associated with ventilation ductwork between the boric acid storage tank room and the central area of the PAB. The ductwork that passed through these penetrations has been removed and the openings replaced with qualified three hour fire barrier penetration seals. Both of these penetrations were restored to operability on July 30, 2003.

Penetration M-1-5-1-F22 was removed from service on July 23, 2003. This penetration involves a non-fire rated equipment hatch assembly that provides access to the boric acid batching tank.

This equipment hatch has been modified to prevent the passage of steam following a HELB event. This penetration was restored to operability on August 1, 2003.

Penetration M-3-5-14-N07 was removed from service on July 11, 2003. This penetration is an electrical blackout located between the boric acid storage tank room and the Unit 2 Rod Drive Room. This seal has been modified to include a Fire/HELB damper assembly. This penetration was restored to operability on August 13, 2003.

6590 Nuclear Road

• Two Rivers, Wisconsin 54241 Telephone: 920.755.2321 NRC 2003-0074 Page 2 During the time that the above listed penetrations were considered out of service, compensatory measures consisting of hourly fire rounds on both sides of the affected barriers were completed in accordance with plant procedures.

A.

Site � resident CW d Cc: Regional Administrator, Region III, USNRC Project Manager, Point Beach Nuclear Plant, NRR, USNRC NRC Resident inspector - Point Beach Nuclear Plant

PSCW

Committed to Nuclear Excellence Point Beach Nuclear Plant Operated by Nuclear Management Company, LLC NRC 2003-0071 GL 97-02 August 13, 2003 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 DOCKETS 50-266 AND 50-301 POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2

MONTHLY OPERATING REPORTS

Attached are monthly operating reports for Units 1 and 2 of the Point Beach Nuclear Plant for the calendar month of July 2003.

Attachment cc: � J. D. Loock, PSCW NRC Regional Administrator NRC Resident Inspector NRC Project Manager 6590 Nuclear Road

• Two Rivers, Wisconsin 54241 Telephone: 920.755.2321

OPERATING DATA REPORT

DOCKET NO. � 50-266 UNIT NAME � POINT BEACH NUCLEAR PLANT - UNIT 1 DATE � 08/04/03 COMPLETED BY Kim M. Locke TELEPHONE � 920-755-6420 REPORTING PERIOD July - 2003 1. DESIGN ELECTRICAL RATING (MWE-NET) 522.0 2. MAXIMUM DEPENDABLE CAPACITY (MWE-NET) 516.0

MONTH YEAR TO DATE CUMULATIVE

3. NUMBER OF HOURS REACTOR WAS CRITICAL 530.5 4,873.5 236,472.9 4. NUMBER OF HOURS THE GENERATOR WAS ON LINE 522.2 4,865.2 232,923.7 5. UNIT RESERVED SHUTDOWN HOURS 0.0 0.0 846.9 6. NET ELECTRICAL ENERGY (MWH) 260,509.0 2,476,321.5 108,027,630.5 DATA REPORTED AND FACTORS CALCULATED AS REQUESTED IN NRC GENERIC LETTER 97-02 DATED MAY 15, 1997

UNIT SHUTDOWNS

DOCKET NO.

TELEPHONE:

50-266 8/04/2003 Kim M. Locke 755-6420 REPORTING PERIOD: � InIv 2003 (Month/Year) F:

S:

1

DURATION

(HOURS) REASON (1) METHOD OF

SHUTTING

DOWN (2)

CAUSE/CORRECTIVE ACTIONS

_ COMMENTS 1 07/15/2003 F 2211 (A) I (3) Unit 1 reactor trip due to failure of 1G06 rod drive MG voltage regulator.

Corrective Action: CA032163 (1) Reason (2) Method A. Equipment Failure (Explain) 1. Manual B. Maintenance or Test 2. Manual Trip/Scram C. Refueling 3. Automatic Trip/Scram D. Regulatory Restriction 4. Continuation E. Operator Training/license Examination 5. Other (Explain) F. Administrative G. Operational Error (Explain) H. Other (Explain)

SUMMARY:

Unit 1 average daily power for the month of July was 350.1 MWe.

On 7/15/03 at 1340 bra, the Unit 1 reactor automatically tripped from 100% Power upon loss of 0-06 rod drive motor-generator (MG) set.

Automatic transfer of the G-06 MG set to 0-07 MO set did not occur.

There were no LERs on Unit 1 in the month of July.

OPERATING DATA REPORT

DOCKET NO. � 50-301 UNIT NAME � POINT BEACH NUCLEAR PLANT - UNIT 2 DATE � 08/04/03 COMPLETED BY Kim M. Locke TELEPHONE � 920-755-6420 REPORTING PERIOD July - 2003 1. DESIGN ELECTRICAL RATING (MWE-NET) 522.0 2. MAXIMUM DEPENDABLE CAPACITY (MWE-NET) 518.0

MONTH YEAR TO DATE CUMULATIVE

3. NUMBER OF HOURS REACTOR WAS CRITICAL 686.6 4,983.6 230,736.7 4. NUMBER OF HOURS THE GENERATOR WAS ON LINE 675.3 4,930.7 227,696.4 5. UNIT RESERVED SHUTDOWN HOURS 0.0 0.0 302.2 6. NET ELECTRICAL ENERGY (MWH) 326,951.0 2,480,545.5 107,268,349,0 DATA REPORTED AND FACTORS CALCULATED AS REQUESTED IN NRC GENERIC LETTER 97-02 DATED MAY 15, 1997

UNIT SHUTDOWNS

DOCKET NO.

TELEPHONE:

50-301 8/02/2003 Kim M. Locke 755-6420 REPORTING PERIOD: July 2803 (Month/Yea r) F: FORCED S: SCHEDULED

DURATION

(HOURS) REASON (1) METHOD OF

SHUTTING

DOWN (2)

COMMENTS

1 07/10/2003 F 68.7 (A) (3) Reactor Trip due to failure of "B" main feedwater pump.

Corrective Action: (CA032158) 2 07/11/2003 F 0 (H) (1) Manual SI and insertion reactor trip signal due to over cooling transient Corrective Action: (CA032159) � ..

(1) Reason (2) Method A. Equipment Failure (Explain) 1. Manual B. Maintenance or Test 2. Manual Trip/Scram C. Refueling 3. Automatic Trip/Scram D. Regulatory Restriction 4, Continuation E.

F.

Operator Training/license Examination Administrative 5, Other (Explain) G. Operational Error (Explain) H. Other (Explain)

SUMMARY:

Unit 2 average daily power for the month of July was 439.5 MWe, 1) At 1342,The Unit 2 'B' Main Feedwater Pump tripped; this was followed by an automatic reactor trip at 1344. All Reactor Protection and Safety Systems responded as required. The Unit 2 'B' Heater Drain Tank Pump also tripped during the transient 2) Unit 2 was in mode 3 with the main feedwater regulating valve controllers in automatic. Upon closure of the reactor hip breakers in preparation for critical approach, the main feed regulating valves opened causing a cooldown of the reactor coolant system (RCS) and pressurizer low level. The operator response sequence included inserting a manual reactor trip signal and manual safety injection. There was no actual safety injection and the charging pumps made up for the RCS shrinkage due to the cooldown. Additionally, there was no reactor trip as the reactor was shutdown.

There was one LER on Unit 2 in the month ofJuly, LER 301/2003-001-01 — Containment Accident Fan Backdraft Damper Failure Results in a Condition Prohibited by Technical Specification 3.6.6.0 - Supplement