ML20084L472

Submits Addl Info to Complete Reporting Requirement Re Failure of Bergen-Paterson Shock Suppressors & Restraints. Failures Caused by Seal Deterioration Will Be Greatly Minimized W/Installation of ethylene-propylene Seals

ML20084L472
Person / Time
Site:	Dresden
Issue date:	08/24/1974
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084L448	List: ML20084L445 ML20084L453 ML20084L462 ML20084L472
References
625-74, NUDOCS 8305230227
Download: ML20084L472 (1)

Text

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o Commonwealth Edison M >j7 One irst F f!ation21 P:an. Crucago, lihnois Asy/J Address Hoply to- Post Othee Box 767 l

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'Dresden Nuclear Power Station R. R. //l Morris, Illinois 60450 August 28, 1974 +F>

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t rit .e Mr. James G. Keppler, Regional Director .-- (C J ,. -

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Directorate of Regulatory Operations-Region III '

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SUBJECT:

. LICENSE DPR-19, DRESDEN L'UCLEAR POWER STATION, UNIT 2. C ADDITIONAL IRF03MATION ON REPORT ON I!!SPECT10N OF BERGEN-PATMISON SHOCK SUPPRESSORS /JID RESTRADTPS.

References:

Letter from W. P. Worden to J. F. O' Leary dated February 21, 1974.

Dear Mr. O' Leary:

In responae to en internal audit made by the off-site review function, the following additional information is supplied to complete the incident reporting requirement.

In evaluating the safety implications of the inoperable snubbers, it is apparent that they do not have a backup system and if a situation aroac for their uce (i.e. earthquake), The pocuibility exists for da. mage to the primary system piping. As a result of these factors, the directive from tho' Atomic Energy Com::tission to inspect these anubbers on a 120-day basis ninimizes the possibility of more inoperable snubbers.

'In regard to previous failures with the snubbers containing poly-urethane, it is believed that with the installation of the ethylene-propyleno coals, the failures due to seal deterioration will be substantially minimized.

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Superintendent .

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Adcress Reply to: Fost Office Sox 767 Chicago Illinois 60697 BBS Ltr.#579-74 Dresden Nuclear Power Station R. R. #1 Morris, Illinois 60450 , ; '

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August 12, 1974 .'o

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Mr. Jacies G. Keppler, Regional Director x 'AUGg3 79,4 ** s 1s. pg., N' Directorate of Regulatory Operations-Region III A { aim .

U. S. Acomic Energy Coc nission 1 , ,

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Glen Ellyn, Illinois 60137 ,p SURJECT: LICENSE DPR-19. DRESDEN_ NUCLEAR PO'.JER STATT_0N. UNIT 92. R3 PORT ON INSPECTION C7 EERGEN PATERSON SHOOK SUPPRESSCRS AND RESTRAINTS.

Dear Mr. Keppler:

This is a courtesy letter to report infor: nation concerning the stations sixth inspection of Bergen Paterson shock suppressors on Unit 2 on July 28, 1974. All 31 snubbers were found to be operable. Three had low oil level and the "as found" and "as lef t" readings are shown fgr these.

Snubler No. Piston Position - Indicator Reading Seal Material 1 3% 2 E-P 2 3 6% PU 2 after filling 3 3 PU 3 4 ,

4 PU 4 M 2 PU 5 3i 2% PU 6 3% 2 PU 7 2% 3 PU 8 3 3 PU 9 -

4 2 No scale E-P 10 3 3 E-P 11 3 2 PU 12 3% 3 E-P 13 3 3% E-P/PU 14 5% . 3 PU 15 4 1 PU ,

16 3% 4 PU

-17 4% 3 PU 18 2 1% E-P 19 2 1 E-P 20 2%

2 E-P 21 4%. 5 PU 22 2 2 E-P 23 4 4 E-P

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Mr. J. G. K:pplar August 12, 1974 Snubber No. Piston Position Indicator Reading Seal >bterial 25 4% 5 E-P' 26 3 5% E-P 26 after filling 3 3% E-P 27 3% 4 E-P 28 2 6% E-P 28 after filling 2 2 E-P 29 3h 3% E-P l

30 3 1 E-P 31 3 2-3/4 E-P

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E-P - Ethylene Propylene Seal Material PU - Polyurethane Seal Material v

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. ,B' Stcpli)enson Superintendent BBS:LJD:do s f

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