ML20100L773
| ML20100L773 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 11/28/1984 |
| From: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-85-089-000 ANPP-31254-TDS, DER-84-36, PT21-85-089-000, PT21-85-89, NUDOCS 8412120076 | |
| Download: ML20100L773 (5) | |
Text
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i I.hh Arizona Nuclear Power Project ggC C -3 fjj pp: 3g P.O. BOX 52034 e PHOENIX. ARIZONA 85072-20u November 28, 1984 ANPP-31254-TDS/TRB Nilli7,,r U. S. Nuclear Regulatory Commission Region V 1450 Maria Lane - Suite 210 Walnut Creek, California 94596-5368 Attention: Mr. D. F. Kirsch, Acting Director Division of Reactor Safety and Projects i
Final Report - DER 84-36
Subject:
A 50.55(e) Reportable Condition Relating To SI Valve Stalls Just Off Closing Seat When Opening Or Closing.
File: 84-019-026; D.4.33.2 A) Telephone Conversation between P. Narbut and T. Bradish on
Reference:
May 17, 1984 B) ANPP-29731, dated June 12, 1984 (Interim Report)
C) ANPP-30354, dated August 29, 1984 (Time Extension)
D) ANPP-30633, dated September 24, 1984 (Time Extension)
E) ANPP-30949, dated October 25, 1984 (Time Extension)
F) ANPP-31204, dated November 21, 1984 (Time Extension)
Dear Sir:
Attached is our final written report of the Reportable Deficiency under 10CFR50.55(e) referenced above.
Very Truly Yours, k
W E.E. Van Brunt, Jr.
APS Vice President Nuclear Production ANPP Project Director EEVB/TRB/nj Attachment cc: See Page Two 8412120076 841128 PDR ADOCK 05000529 6
PDR I i TE*2 7,
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- Mr. D. F. Kirsch DER 84-36 Page Two
-cc:-
Richard DeYoung, Director Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20555 T. G. Woods,-Jr.
s D. B. Karner -
. W. E. Ide D. B. Fasnacht A. C. Rogers L. A. Souza D. E. Fowler T. D. Shriver C.-N. Russo B. S. Kaplan J. R. Bynum J.~M. Allen A. C. Gehr.
W. J..Stubblefield.
W. G. Bingham R. L.-Patterson R. W. Welcher H.'D.' Foster D. R. Hawkinson R. P. Zimmerman L. Clyde M. Matt 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 1
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FINAL ~ REPORT - DER 84-36
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. DEFICIENCY EVALUATION 50.55(e)
ARIZONA PUBLIC SERVICE COMPANY.(APS)
PVNGS UNIT 2-
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Descr16 tion of Deficiency
. Unit 2 High Pressure Safety; Injection'(HPSI) valve 2JSIBUV636'was.
4-1 f ' disassembled for inspection as srequested by Borg-Warner. and
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? Combustion Engineering (C-E) to determine the cause'of valve' stall.-
Site inspection of the valve revealed chatter marks on the -interior.
ikEalve>bodysurfacesand'excessiveiclearancesbetweenthediscguides-and.the valve bore. This condition was documented by NCR SM-3941.
As a result of theLabove condition, the valve was cut out..and.sent to Borg-Warner for further inspection and repair.- Borg-Warner'sJ inspection revealed. extensive cavitation damage to the valve body with a region of deep' erosion extending approximately halffway through dhe-body and a second region.of.significant pitting extending into the, piping (Reference 1).
The area of deep erosion violated the-minimum wall-thickness requirement of 0.399 inches as specified-in the Operation and Maintenance Instruction Manual, Bechtel Log'No.
N001-11.04-263.
The subject valve is a 2 inch, motor operated globe valve-manufactured by Borg-Warner and supplied by C-E.
Evaluation There are eight HPSI injection valves per. unit. Their tag numbers'
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are'11sted below:
JSIBUV616
-JSIAUV617 JSIBUV626 JSIAUV627-JSIBUV636 JSIAUV637 JSIBUV646 JSIAUV647 As stated in Section I, valve 2JSIBUV636 was severely damaged duelto;,
cavitation.
In evaluating this deficiency, radiographic examinations were performed on the remaining seven valves in Unit 2 to determine if they also;were damaged.' The radiographic examination-revealed indications of cavitation damage in all seven valves (Reference 1).
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Ultrasonic thickness testing of the valves indicated that the-remaining wall thickness exceeded the minimum wa11' thickness of 0.399 inch on all valves except 2JSIBUV616. JA precise wall thickness measurement on. valve 616 could not be.obtainedJdue to interference of
>the testing equipment with nearby components.
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Final Report
-DER _84-36 Page Two Radiographic examination of the eight Unit 1 injection valves revealed no cavitation damage. However, Unit i valve IJSIAUV627 was disassembled in accordance with NCR SM-4957 to inspect for chatter marks lto determine if'the chatter marks found on the Unit 2 valve resulted from cavitation or if they occurred due to a deficiency in
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the valve. No chatter marks were found on the Unit i valve.
Therefore, the chatter marks on the Unit 2 valves are attributed to cavitation.
This deficiency is isolated to the Unit 2 HPSI injection valves. The root cause is attributed to high velocity flushing through these valves in accordance with startup flush procedure 91FL-2SIO2.
The Unit 2 HPSI system was flushed at higher velocities and for longer durations than Unit 1.
Flows of 600 to 700 gpm through these valves have been reported. The normal expected flow is approximately 277 gpm. Additionally, the valves were throttled for hours at a time during recirculation flushes in accordance with the flush procedure.
Unit 1 and the remainder of the Unit 2 safety injection system were not flushed at velocities much higher than normally expected.
Therefore, they are not suspected of having cavitation damage.
II.
Analysis of Safety Implications The function of the HPSI system is to inject borated water into the Reactor Coolant System (RCS) during a Loss of Coolant Accident (LOCA). Failure of the injection valves to operate or unintain their pressure boundary-integrity would prevent the.HPSI system from performing its intended safety function.
This condition is therefore evaluated as reportable under the requirements of 10CFR50.55(e); since, if this condition were to remain uncorrected it could represent a significant safety condition.
This project evaluates this condition as not reportable under the -
requirements of 10CFR Part 21, since this deficiency constitutes operational daar.pt to a component rather than the delivery of a defective component.
III.
"orrective Action Although ultrasonic thickness testing indicated that six of the subject valves were still within acceptable minimum wall thickness requirements, all eight valves in Unit 2 were removed and replaced with valves from Unit 3.
This work was performed per NCRs SM-3941 on May 1, 1984 and SM-4626,on August 24, 1984.
Final Report DER 84-36 Page Three The piping directly downstream of the subject valves will be inspected for damage per NCR SM-5228 when the valves are removed per DCP 2SM-SI-150 to perform work not associated with this deficiency.
Damaged piping will be replaced as required and documented on-NCR SM-5228.
The flushing procedure for Unit 3, when issued, will ensure the excess flows observed in Unit 2 will not occur.
IV.
References 1.
Letter, PVNGS-0JZ-M84-187, August 9, 1984 2.
Letter,. V-CE-30587, July 19,1984
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