ML20106B574

Rev 1 to Final Deficiency Rept DER 83-63 Re Failure of Borg-Warner HPSI Isolation Valves to Open Against HPSI Pump a & B Flows.Initially Reported on 830920.Site Insp Conducted to Verify Torque Spring Packs Modified

ML20106B574
Person / Time
Site:	Palo Verde
Issue date:	10/09/1984
From:	Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	Bishop T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
ANPP-30783-TDS, DER-83-63, NUDOCS 8410230341
Download: ML20106B574 (6)

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Arizona Public Service Company

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October 9; 1984

ANPP-30783-TDS/IR b E

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' U. S. N iclear Regulatory Commission Region.V

' Creekside ' Oaks Office Park '

1450 Maria Lane - Suite 210 c Walnut Creek, Calif ornia - 94596-5368

- Attentions . Mr. T. W. Bishop; L Director Division of Resident-Reactor Projects and Engineering Programs

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Subject:

Final Report, Revision 1 - DER 83-63

- A-50.55(e) Reportable Condition kelating To .HPSI Isolation Valves By Borg-Warner Failed To Open Against HPSI 'A' And

'B' Pump Flows..

File: 84-019-026; D.4.33.2

Reference:

A) Telephone Conversation between P. Narbut and R. Tucker on September 20, 1983 B) ANPP-28072, dated October 24,1984 (Interim Report)

C) ANPP-28954, dated February 28; 1984 (Time Extension)

D) ANPP-29131, dated March 22, 1984 (Final Report)

E) Telephone conversation between P. Narbut and T. Bradish on April 2, 1984 F) ANPP-29395, dated April 30,1984 (Time Extension)

G) ANPP-29971, dated July 16,1984 (Time Extension)

H) ANPP-30420, dated September 4,1984 (Time Extension)

I) ANPP-30590, dated September 20, 1984 (Time Extension)

Dear Sir:

Attached is Revision 1 of our final written report of the Reportable Deficiency under 10CFR50.55(e), referenced 'above. This Revision updatto the Condition Description and the Corrective Action.

4 Very truly yours,

, CULA -

G LR hOgg S

ho 0528009 E. E. Van Brunt, Jr.

APS Vice President PDR Nuclear Production ANPP Project Director EEVB/TRE/nj At tachment --

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W^ DER 83-63, Revision 1 '

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It cc:- Richard DeYoung,' Director Office !of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555.

T. G. Woods, Jr.

D. B. Karner W. E. Ide D. B. Fasnacht A. C. Rogers L. A.-Souza D. E. Fowler T. D. Shriver LC. N. Russo J. Vorees J. R. Bynum J. M. Allen A. C. Gehr W. J. Stubblefield W. C. Bingham R. L. Patterson R. W. Welcher H. D. Foster D. R. Hawkinson R; P. Zimmerman L. Clyde M. Woods T. J. Bloom D. N. Stover J. D. Houchen J. E. Kirby D. Canady Records Center Institute of Nuclear Power Operations 1100 circle 75 Parkway, Suite 1500 Atlanta, GA 30339 s

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i - FINAL MPORT; REVISION 1.- DER 83-63

. DEFICIENCY EVALUATION ~ 50.55(e) ,.

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. .PVNGS UNITS l1,^2,M3 ~

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I. . Description of Deficiency -

' Two separate deficiencies have' been reported for the eight High Pressure Safety Injection valves. that isolate. the

~ injection path to'the' cold legs. The. description of these

,  : deficiencies along with their corresponding safety implication and corrective actior. are delineated as. Items "A" and "B" below.

A. During preoperational testing on Units 1 and 2, the' 2-inch Motor-Operated High Pressure Safety Injection (HPSI) valves, failed to open against the discharge . pressure of . . ,

HPSI pumps train A' and B. The valves would not open beyond  ;

1. .the bypass limit switch setpoint. The cause of this condition is attributed to incorrect torque switch settings  ;

and resulted in loosening of the valve yoke f rom the bonnet '

assembly. Torque switches are set at the_ factory, however,.

field adjustment is required as a normal ' evolution refinement to tailor valve operability to ' actual as-built installation and system parameters. Adjustment is within. ,

the minimum / maximum range of adjustment as specified 7 (torque limit plate) by the manufacturer. Further investigation revealed that this problem is generic to all the Borg-Warner Model 77620-2 HPSI valves furnished to PVNGS.

The HPSI, valves are supplied by Combustion Engineering

. (C-E) and are manufactured by Borg-Warner Nuclear Valve .

r Division. They are identified by the following unit tag numberst

, 1, 2 & 3 - SIB-UV-616 1, 2 & 3 - SIA-UV-617 r 1, 2 & 3 - SIB-UV-626 1, 2 & 3 - SIA-UV-627  ;

1, 2 & 3 - SIB-UV-636 1, 2 & 3 - SIA-UV-637 o 1, 2 & 3 - SIB-UV-646 1, 2 & 3 - SIA-UV-647 The above condition was addressed in the Final Report for DER 83-63 (dated March 22, 1984) and corrective action was p rescribed.

B. On March 30, 1984 af ter the above conditions had been -

corrected in Unit l' and while conducting further  !

prerequisite testing, valves 1-SIA-UV-627 and 1-SIA-UV-647

,f ailed performance tests when their motors remained i energized af ter completion of the closing stroke.

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Mr. T. W. Bishop DER 83-63, Revision 1 Page Two A current imbalance in the 3 phase motor circuit was noted, and it was suspected that the Limitorque motor operators

< were not developing sufficient torque to actuate the "close" torque switch.

It was determined by Borg-Warner that the cause of this condition was due to improper setting of the torque switch bypass limit switch. This effectively removes the torque switch f rom the circuit. The torque switch bypass limit switch is also factory set, but field adjustment may also be required as determined by operability perf ormance testing. The observed current imbalance was determined to be within manuf acturer's specifications (Ref erence C-E letter V-CS-21694).

.In addition to the valves listed above, HPSI pump mini-flow isolation valves 1, 2 & 3 - SIA-UV-666 and 1, 2 & 3 -

SIB-UV-667 have similar Limitorque motor operators (Model SMC-04-7.5). These latter valves, however, are of a diff erent type (Borg-Warner Model No. 77620-4 in Unit 1 and Model No. 77620-3 in Units 2 & 3). Operational problems with valve SJA-UV-667 are addressed in DER 84-72. No operational probicas have been experienced with valve

• SIA-UV-666.

II. Analysis of Safety Implications A. The HPSI valves are required to open and allow the HPSI pumps to deliver water to the reactor during a email pipe break LOCA or in the recirculation mode af ter a large pipe break LOCA to maintain the reactor coolant inventory. Tim identified failure mode of these valves would preclude the Safety Injection System f rom performing its safety-related function.

Based on the above, this condition is evaluated as reportable under the requirements of 10CFR50.55(e); since, if this condition were to remain uncorrected, it would represent a significant safety condition.

The PVNCS Project considers the deficiency to be niso reportable under the requirements of 10CFR Part 21. Letter V-CE-19168, dated October 21, 1983, indicates that this condition is limited to PVNCS Units 1, 2, and 3.

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' DER-83-63; Revision 1.

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, iB. The incorrect setting of = the close limit switches is also -

S evaluated;as reportable .under the. requirements of -

N e , < 10CFR50.'55(e); sincei'ifJ this condition were .to remain <

'C-uncorrected; it could' possibly prohibit the valves from-opening.and.this would represent'a significant safety concern. . This condition is evaluated as not reportable .t under the requirements'of'10CFR Part 21;' since there is no-defect with the? basic component.

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III. Corrective Action m

, ~ A. .Fina1 ' disposition of NCR SM-2591 and input f rom C-E: letter V-CE-19310 define the -corrective action as f ollows: .

For valves'SI-616; 617; 626; 627,- 636; 637;1646; and 647

- for all 3 units is as follows:

1. A s'ite inspection was made. by Borg-Warner of all valves 7 to verify that_ a 1979 factory modification to the torque spring packs has been incorporated.

2. Adjustment of the full open limit switch to stop the - -

opening; valve stroke at 95% plus/minus 4%. This maintains the present practice .of opening' these valves to their full open position.

3. Adjustment of the opening torque switch 1- pass ~ 11mit switch to 65% plus/minus 5% of. valve stroke (stem travel). This adjustment will prevent the motor operator from shutting off on torque below the C-E maximum specified Cv.. .

4. Settings for both the opening and closing torque switches are to be between 3.0 and 3.25. Unit 1 has been set to 3.0

5. Thetyoke tack-welded to the bonnet to prevent loosening.

6.1 Adjustment of the "Open" light limit switch setpoint to go out at 1/8 inch of' stroke before the valve is seated. Limitorque's stated accuracy for limit switch

_ setting is pluc/minus 1/8 inch. -

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DR 83-63; Revision- 1 a . Page'Four

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'The following actions are also being taken in addition'to those outlined.by C-E:

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7. NCRs. SJ-2591 ~ for Unit 1 and .SE-2744 f or Unit. 2 will- be dispositioned as " Repair." The repairs will be completed prior to fuel load for the respective units.

8.~ Unit 3 valves will be modified: via' DCP 3CM-SI-113 prior to' f uel load..

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9. All unit ~ valves will be retested in accordance with Test Procedure 91PE-lSIO8; on completion of modification

. program.

, 10. A copy of this report has.been sent to C-E and Borg-Warner for their review under the requirements of

~10CFR 21.

B. C-E letter V-CE-21694 outlines actions taken in troubleshooting the close limit switch problem.

1. The close limit switches were re-set to the correct settings which resulted in proper operation of the:

valves.

2. During troublesi oting and to f acilitate completion of the testing program; the Limitorque motor-operators were replaced; however, subsequent testing at Borg-Warner has confirmed that the motors were developing the proper torque and Limitorqu'e has confirmed that the observed motor phase imbalance was acceptable.

3. All Unit 1 valves have been confirmed to be operating properly as part of. Test Procedure 91PE-1-cI08. Units 2

,. & 3 valves will be tested in accordance with the same procedure during their respective startup testing programs.

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