ML20090H502

Final Deficiency Rept,Item 109 Re Broken Valve Stem & Guide Pin on 24-inch Globe Valve.Initially Reported on 840203. Cause for Guide Pin Failure Undetermined.Valve Component Damage Caused by Excessive Vibration

ML20090H502
Person / Time
Site:	Fermi
Issue date:	07/13/1984
From:	Jens W DETROIT EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
104, 109, EF2-69276, NUDOCS 8407260331
Download: ML20090H502 (2)

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/b /O b3 Wayne H. Jens N e Ope ations Deholt 2000 Second Avenue 25 M $$NIEE""*** July 13, 1984 EF2-69276 k

Mr. James G. Keppler s Regional Administrator

' Region =III U. S.~ Nuclear Regulatory-Commission 799 Roosevlet Road

Glen

. Ellyn, Illinois ' 60137

Reference:

- (1) Fermi 2 NRC Docket No. 50-341 (2) Letter, D. A. Wells to J. G. Keppler, February 3, 1984, QA-84-0078

Subject:

Final Report of 10CFR50.55(e) Item 109

" Broken Valve Stem and Guide Pin on 24 Inch Globe Valve" This is Detroit Edison's final report concerning a broken valve stem and guide pin on a 24 inch globe valve. Item 109 was originally reported as a potential deficiency on February 3, 1984, and subsequently documented in Reference (2).

Description of the Deficiency Valve V15-2018 is a 24 inch flow control valve in the RilR service ' water system manuf actured by the Wm. Powell Company. During checkout and initial operation flushing of the Division I RHR service water system, severe vibrations were experienced by the flow control valve. The valve was

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inspected and the guide pin was found to have been broken off below the disc on the valve. This allowed the disc to vibrate and induced cyclic stresses in the valve stem.

Consequently the valve stem failed due to fatigue.

Wm. Powell Company performed a quantitative spectrographic analysis, a visual inspection, and a visual microscopic examination of polished and etched specimens from the guide pin. From.these examinations, no cause of the guide pin f ailure could be deternined.

8407260331 840713 (M PDR ADOCK 05000341 S PDR \g rr

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Mr. James G. Keppler July.13, 1984 EF2-69276 Page 2 Based on the history of operation of this valve, the damage to the valve components appears to be due to excessive vibration. The vibration was apparently caused by operation of the RilR service water loop with flow rates that required throttling the valve outside its optimum range. It has been

' determined that because of a very low piping resistance, the valve was absorbing nearly all of the system pressure drop during checkout and initial operation.

Analysis of Safety Implications This failure could have adversely affected the capability of the RHR service water system to perform its heat removal

- function.

-Corrective Action The' damaged components of valve V15-2013 were replaced. The identical valve (V15-2019) in Division II of the RilR service water system was examined and no similar damage was found.

An orifice was installed in each loop of the RilRSW piping to

. reduce the. pressure drop across the valves. During subse-

,quent preoperational testing of the valves, no significant valve vibration was-observed. Operating personnel have been made awar.2 of the operating characteristics of these valves,

'and ~ the Syst'em Operating. Procedure (SOP) will be revised to limit valve operation outside the optimum throttling range.

This is' Detroit Edison's final report on this item. If you have' questions'concerning this matter, please contact Mr . ' . Lewi a P. Bregni, _313)

( 586-5083.

Sincerely, f

Y *

.! cc: Mr. P. 7.M. Byron- V Mr. R. C. DeYoung V Mr. . R. C. Knop r

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