TXX-7063, Final Deficiency Rept CP-87-33 Re Auxiliary Feedwater Pump Motor Fans.Initially Reported on 870708.Vendor Evaluation Found No Adverse Effect from Fan Installation in Reverse Direction.Condition Not Reportable Per 10CFR50.55(e)

Final Deficiency Rept CP-87-33 Re Auxiliary Feedwater Pump Motor Fans.Initially Reported on 870708.Vendor Evaluation Found No Adverse Effect from Fan Installation in Reverse Direction.Condition Not Reportable Per 10CFR50.55(e)

ML20237D923
Person / Time
Site:	Comanche Peak
Issue date:	12/14/1987
From:	Counsil W TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
CP-87-33, TXX-7063, NUDOCS 8712280033
Download: ML20237D923 (4)

Text

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" 9 Log # TXX-7063

,,,, ,,,,,_ File # 10110 r = 910.4 1UELECTRIC " # IUC(" U 5'}

wmim c. coum,n December 14, 1987 Emume We Prmlernt U. S. Nuclear Regulatory Commission ATIN: Document Control Desk i

Washington, D.C. 20555 l

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SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) l DOCKEl NOS. 50-445 AND 50-446

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AUXILIARY FEEDWATER PUMP MOTOR falls SDAR: CP-87-33 (FINAL REPORT)

Gentlemen:

On July 8,1987, we verbally notified your Mr. R. F. Warnick of a deficiency involving the rotational direction of the Auxiliary Feedwater (AFW) Pump Motor Cooling fans for Units 1 and 2. Our latest report on this issue was logged lu-7020, dated November 30, 1987. After further evaluation, we have determined that this issue is not reportable under the provisions of 10CIR50.55(e).

Specifically, the direction of rotation of the AFW Pump Motors was reversed by swapping the motor leads, but the unidirectional motor cooling fan installation was not changed to correspond to the new rotational direction contrary to requirements of the vendor technical manual.

1he deficiency was discovered during the Unit 2 testing of the Motor Driven Auxiliary feedwater Pumps and was documented by Test Deficiency Report (TDR) 4870. The disposition of the TDR required reworking the applicable Unit 2 motors, while Unit 1 motors were deemed acceptable based on previous tests performod on the motors. A subsequent inspection of the Unit 1 motors identified that the blower fan installations were also incorrect.

A review of the documentation associated with this condition ascertained that the AFW Motoi Specification 2323-ES-ID did not specify the required rotational direction of t he motor. A review of the AFW Pinnp Specification 2323-MS-7 disclosed t. hat the rotational direction was specified t.o be in the counter-clocl. wise (CCW) direction, but did not qualify the dio ct inn of intation by including t he diiect ion at which f hn pump i'; si"wed. D. nod on om leat rol a f ional i"rpiii emonI , ,unt t. in< " Iho mo t ni s and pnmps wm e mannfa<iuied and i

r,upp l i ed h v i wn d i f i e ron t v endo r', , t he mot ori woro 1. hipped with a intational direction (based on the biower tan configuration) opposite from the direction i required to service the pumps. j l

8712280033 071214

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l TXX-7063 December 14, 1987 i Page 2 of 4 )

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To determine the safety significance of this issue, the motor supplier (Westinghouse) evaluated the effect on auxiliary feedwater pump motor qualified life when operating with the unidirectional motor blower fans installed in the reverse direction, i.e., opposite to the direction of the motor rotation.

The evaluation was based on motor test data from CPSES Test Report ICP-PT-37-1 i Revision 0. This test data was recorded with the notor blower fans installed j in the reverse direction at pump flow rates of 485 to 540 gpm, with j corresponding motor current draws of 44 to 47 amps. These operating points I represent the pump full flow conditions for safeguards applicatiora The I motor rated full load current is 53 amps; thus, the motor is oversized for  !

this application. Due to this conservative design, the motor temperature rise with proper fan installation would not approach the maximum allowable temperature rise for Class B insulation and margin is available for the increased temperature rise, which occurs with the reversed fan installation.

In order to use the test data from Test Report ICP-PT-37-1 Revision 0 for a motor qualified life evaluation, Westinghouse had to determine if the motor winding temperature stabilized during the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> test. The Westinghouse evaluation was based on the plots of the winding temperatures and ambient temperatures documented during the test period. Motors of this type typically reach a stabilized stator winding temperature within six to eight hours.

Following the first eight hours of the test, the average winding temperature rise is approximately 0.25 degrees F (0.14 degrees C) per hour. Despite l variations in the ambient temperature profile, the worst-case winding I temperature variation was within 2 degrees F per hour after the initial eight  !

hour period. The slight temperature rise continuation over the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> period was attributable to the continued rise in the ambient temperature. A criterion for determining winding temperature stabilization is provided by the  ;

Test Procedure for Polyphase Induction Motors and Generators, IEEE-112-1978, '

Paragraph 5.6.3, which specifies a maximum temperature rise of I degree C for two consecutive test points at half hour intervals (equivalent to 3.6 degrees  ;

F per hour). The average winding temperature rise during the auxiliary feedwater pump motor test was substantially below this criterion and the test data conclusively demonstrated winding temperature stabilization.

Report ICP-PT-37-1 Revision 0, Data Sheet 29C, identifies a maximum motor l winding temperature of 177.6 degrees F with an initial winding temperature of i l

79.4 degrees F, which corresponds to a 98.2 degree F winding temperature rise.

The maximum accident condition ambient temperature for these motors is 122 degrees F. The maximum calculated motor Winding temperature during accident conditions is 104.55 degrees C (220.2 degrees F). This was determined by adding the temperature rise of 98.2 degrees F at pump full flow conditions to the ambient temperature of 122 degrees F. This method of adding absolute winding temperature rise to a projected ambient temperature is frequently used by Westinghouse motor divisions and is valid as long as the predicted winding temperature does not approach the motor thermal runaway temperature.

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December 14, 1987 Page 3 of 4 The Westinghouse large Motor Division report " Environmental Qualification of Class 1E Motors for Nuclear Out-of-Containment Use" states (on page 91) that j Class B insulation has a 40 year qualified life for continuous operation with i at total winding temperature of 105 degrees C (221 degrees F). Westinghouse concluded that the measured winding temperature rise from Report ICP-PT-37-1 Revision 0 indicates that the maximum predicted auxiliary feedwater pump motor winding temperature with reversed motor blower fans would be 104 degrees C and reevaluation of the qualified motor life of 40 years is not required.

In addition to the Westinghouse evaluation, a review of other motor requirements (manuals, drawings) was performed to ensure that their fans would not be installed with improper rotation. The following safety related motors have fans designed to rotate in either direction and were ordered from a single supplier. Therefore these motors are outside the scope of this deficiency.

cpl-CCAPCC-01 CP2-CCAPCC-01 COMPONENT COOLING WATER SYSTEM cpl-CCAPCC-02 CP2-CCAPCC-02 COMP 0NENT COOLING WATER SYSTEM CPI-CTAPCS-01 CP2-CTAPCS-01 CONTAINMENT SPRAY SYSTEM cpl-CTAPCS-02 CP2-CTAPCS-02 CONTAINMENT SPRAY SYSTEM CP1-CTAPCS-03 CP2-CTAPCS-03 CONTAINMENT SPRAY SYSTEM cpl-CTAPCS-04 CP2-CTAPCS-04 CONTAINMENT SPRAY SYSTEM TBX-RHAPRH-01 TCX-RHAPRH-01 RESIDUAL HEAT REMOVAL SYSTEM ,

TBX-RHAPRH-02 TCX-RHAPRH-02 RESIDUAL HEAT REMOVAL SYSTEM TBX-CSAPCH-01 TCX-CSAPCH-01 CVCS SYSTEM (CENTRIFUGAL)

TBX-CSAPCH-02 TCX-CSAPCH-02 CVCS SYSTEM (CENTRIFUGAL)

CPI-SWAPSW-01 CP2-SWAPSW-01 SERVICE WATER SYSTEM CPI-SWAPSW-02 CP2-SWAPSW-02 SERVICE WATER SYSTEM The following motors have unidirectional fans and were purchased as a unit with the associated pump. However to ensure proper fan rotation a field check is being performed. A field check of the Unit 2 motors verified proper fan rotation. Initial investigation of the Unit I motors has determined there is no reason to suspect improper fan rotation. The field verification for the Unit 1 motors will be completed by December 31, 1987.

TBX-SIAPSI-01 SAFETY INJECTION SYSTEM TBX-SIAPSI-02 SAFETY INJECTION SYSTEM TCX-SIAPSI-01 SAFETY INJECTION SYSTEM TCX-SIAPSI-02 SAFETY INJECTION SYSTEM The AFW motors were the only safety related motors designed with unidirectional fans and supplied separate from the pump vendor.

I Based on the above information we have concluded that, in the event this i condition had gone uncorrected, no adverse affect on the safe operation of the plant would have occurred.

i TXX-7063 December 14, 1987 Page 4 of 4 4

DCA-62373 has been written to revise design. specification 2323-ES-ID to specify rotational direction of the Auxiliary Feedwater Pump Motors. DCA-62374 has been written to revise design specification 2323-MS-7 to clarify .j rotational direction of the Auxiliary Feedwater Pumps (motor driven).

To preclude recurrence of this condition, specifications associated with safety-related systems, structures and components are being reviewed. The program will perform a detailed review of specifications and associated implementing procedures. The review will conclude by ensuring appropriate specifications are revised.

1 Very truly yours, (fl$ .

W. G. Counsil MCP/mgt c - Mr. R. D. Martin - Region IV Resident Inspectors, CPSES (3) l l

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