ML20041D490

Interim Deficiency Rept 2 Re Impeller Wear Rings.Technical Evaluation Being Performed by Manufacturer.Requests Extension for Submittal of Final Rept Until 820409

ML20041D490
Person / Time
Site:	Beaver Valley
Issue date:	02/25/1982
From:	Woolever E DUQUESNE LIGHT CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8203050352
Download: ML20041D490 (3)

Text

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%,;r';f;;- FEB 2 51982 15219 United States Nuclear Regulatory Commission ,

Region I g 0) 631 Park Avenue King of Prussia, PA 19406 (

RECEIVED 9 9-ATTENTION: Mr. R. Haynes, Administrator

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SUBJECT:

BEAVER VALLEY POWER STATION - UNIT NO. 2 E y Docket No. 50-412 4 Auxiliary Feedwater Pump g 10 Impeller Wear Rings - Significant Deficiency Report 81-04 Gentlemen:

This letter is Interim Report Number 2 conceraing Significant Deficiency 81-04.

Our letter 2DLC-4402 dated December 18, 1981 indicated that a final report on this deficiency would be submitted by February 26, 1982; however, delays in the technical evaluation being performed by the pump manu f ac tu re r have fo rc ed the extension of this date to April 9, 1982. The attached Interim Report Number 2 provides a discussion of the status of the resolution of the problem.

DUQUESNE LIGHT COMPANY

/I By ~ -

y W Woolever Vice President Attachment cc: NRC Document Control Desk Ms. E. Doolittle Project Manager Mr. G. Walton NRC Resident Inspector 8203050352 820225 PDR ADOCK 05000412 S PDR f6 q,7S, I

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- Mr. 'R. Haynes, Administrator Significant Deficiency Report 81-04 Page RMK-KAT/sjd bec: R. J._Washabaugh H. A. VanWassen T. D. Jones D.11. Willians E. J. Woolever A. J. Zelesnak J. J. Carey R. J. Swiderski

11. P. Williams F. Salmon R. Coupland C. R. Bishop P. RaySircar J. Pedro (NUS)

C. N. Dunn C. E. Ewing J. E. Walsh R. M. Kight BV-2 Licensing File (KAT)

References:

1) 2DLS-12952 dated 12/15/81 "Auxilia ry Feed Pump Impeller Ring, 2BV-208, Cracking Potential Reportable Deficiency" 2)- 2DLC-4402 dated 12/18/81 "Auxilia ry Feedwater Pump Impeller Wear Rings Significant Deficiency Report 81-04"

3) 2DLS-13348 dated 2/05/82 " Auxiliary Feed Pump Impeller Ring, 2BV-208, Cracking Potential Reportable Deficiency" l.

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9 INTERIM REPORT #2 o

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AUXILIARY FEED PUMP IMPELLER. RING CRACKING AT BEAVER VALLEY POWER STATION - UNIT NO. 2 l '. 0

SUMMARY

During a post test inspection of the Trubine Driven Auxiliary Feed Pump (2FWE-P22) (TDAFP) being perfomed at the Terry Turbine Corporation, on September 10, 1981, several cracked impeller wear rings were discovered. Should this condition also exist on the Motor Driven Auxiliary Feed Pumps (2FWE-P23A&B) (MDAFP) there is a potential for complete wear ring failure and loss of pump performance.

2.0 IMMEDIATE ACTION TAKEN Upon discovery of the cracked impeller wear rings on the TDAFP, the entire pump / turbine assembly was returned to the Bingham Willamette Company (BWC) in Portland, Oregon, for a complete engineering assessment.

4 The BWC engineering assessment attributed the impeller wear

, ring cracking to the use of previously used rings when the impeller was replaced prior to the delivery of the pump. The additional stresses imposed on the rings by removal and re-installation are the probable cause of the cracking.

Because the MDAFP impellers were also replaced, it is possible that similar problems exist in these pumps. The rotating elements from the MDAP's were removed, visually inspected,.and ,

returned to the BWC for evaluation. No cracks were discovered  !

in the visual inspection.

3.0- DESCRIPTION OF DEFICIENCY Cracked impeller wear rings at the securing pin hole juncture on.

various impeller stages of the TDAFP have been evaluated by the BWC. Because of the similarity in construction of the TDAFP and the MDAFP's, it has been determined that there is a potential for ,

impeller wear' ring f ailure and loss of pump performance on these pumps also.

4.0 ANALYSIS OF SAFETY IMPLICATION Al reduction in auxiliary feed pump. performance could result in

reduction of residual' heat, removal. capability.

5.0 CORRECTIVE ACTION TO REMEDY DEFICIENCY (10 3

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- The MDAFP wear rings haoe been_ removed and replaced with new wear rings. It is anticipated that this will correct the deficiency.

However, the final- determination of the cause of. the problem and the final' assessment of the adequacy of this solution will not

( be complete until'the inspection report has been reviewed.

i 6.0 FINAL' REPORT A final-' report will..be submitted by April 9, 1982.

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