ML20236N713

Part 21 Rept Re Potential Problem W/Vibration in Lube Oil & Jacket Water Sys.At Rancho Seco Site,Fatigue Cracks Found in Welds of Support Members in Lubricating Oil Sys.Cracks Due to Vibration in Lube Oil Sys.Addl Preventive Action Taken

ML20236N713
Person / Time
Site:	River Bend, Rancho Seco, 05000000, Shoreham
Issue date:	08/05/1987
From:	Guntrum B IMO DELAVAL, INC.
To:	NRC
References
REF-PT21-87, REF-PT21-87-156-000 141, PT21-87-156, PT21-87-156-000, TAC-63030, NUDOCS 8708120074
Download: ML20236N713 (3)

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Imo Delaval Inc.

Enterprise Engine Division Enterprise Way and Mth Avenue I D Oakland, CA 94621 P. O ikix 2161 415 577-7400 August 5, 198/

Director, Office of Inspection and Enforcement US Nuclear Regulatory Commission Washington, DC 205S3 Report #141 i

Dear Sir,

in accorance with the requirements of Title 10, Chapter 10, Code of Federal Regulations, Part 21, IMO Delaval Inc.

hereby notifies the Commission of a potential defect in a component of a DSR engines Standby Diesel Generatbr. There exists a potential problem with vibration in the lube oil and jacket water systems.

IMO Delaval has supplied DSR with this potential defect to tne f ollowing sites:

MIILill M11b 9tM1AL NO. MOpEL LlLCO Shoreham 74010-12 DSR-48 GULF STATES Hiver Band 740J9-40 DSR-48 SMUD Rancho Seco 81015-16 DSH-48 At tne Rancho Seco site, fatigue cracks have been found in the welds of support members in the lubricating oil system.

Tnese cracks are due to vibration in the lube oil system believed to be induced by the on-engine lube oil pump. These cracks nave occured in supports and welded joints resulting in minor lube oil leakage. It is reasonable to postulate, however, that left uncorrected the lube oil piping could ultimately fail causing a sufficient loss of lube oil to render tne diesel engine inoperable.  ;

Vibration in the jacket water system at the same site has resulted in a minor violation of the pressure boundary.

Again, left uncorrected this crack could propagate to the point wnere a major failure could occur rendering the diesel engine Inoperative. In this case, probable cause has not been determined, requiring further investigation.

In neither case, is there concern of an immediate failure.

There are alarms in the systems to alert the operators of a pressure boundary failure. Additionally, the potential problems are of a progressive nature, not susceptible to an immediate catastrophic failure mode.

8708120074 G70805 ,

PDR ADOCK 05000312 S PDR _

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Page 2 August 5, 1987 US Nuclear Regulatory Commission Corrective action is being taken at the Rancho Seco site with additional preventive action being investigated. Wnile the other listed sites have similar system and component designs, neither excessive vibration nor reiated failures of piping or supports have been reported. It is recommended, however, that these sites monitor the subject syste=s and report any excessive vibration levels to IMO Delaval Customer Services.

A copy of tnis ietter will be sent to all of the sites referenced in Paragraph 2 of this letter as indicated by the carbon copy iist.

Our evaluation of this matter was concluded on August 3, 1987.

Very truly yours,

, w=

3 e_ , 4 I

Bruce C. Guntrum Manager, Quality Assurance BCG/dfa

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Page 3 August 5, 1987 US Nuclear Hegulatory Commission c.c. Long Island Lighting Company Shoreham Nuclear Power Station North Country Road Wading River, New York 11791 Attn: Mgr. Nuclear Operations Support Dept.

Gulf States Utilities Company Stone & Weoster Engineering Company Cherry Hill Operations Center 3 Executive Campus P.O. Box 5200 Cherry Hill, New Jersey 08034 Attn: Project Manager (J.O. #12210)

Gult States Pro.iect Sacramento Municipal Utility District P.O. Box 16830 Sacramento, CA 95813 Attn: Mr. Cranston Nuclear Engineering Dept. M.S. 208 Judy R. Beal Purchasing Dept. M.S. 50 1

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