ML20134L108

Part 21 Rept Re Defect in Component of Nordberg Model FS1316HSC Sdg.Nak Engineering,Inc Has Established & Adopted Procedures to Assemble Fuel Oil Lines & Climinate Possible Defective Condition

ML20134L108
Person / Time
Site:	Mcguire, Brunswick, McGuire
Issue date:	10/10/1996
From:	Nelson N AFFILIATION NOT ASSIGNED
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-96712 NUDOCS 9611200157
Download: ML20134L108 (1)

Text

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420 AVIATION BLVD., SANTA ROSA, CA 95403 TELEPHONE: (707) 542-9996 FAX: (707) 542-6866 Oct 10,1996 Document Control Desk 4

U.S. Nuclear Regulatory Commis.sion Washington, DC 20555

Dear Sir,

Pursuant to my letter dated Aug. 5,1996 and in accordance with the requirements of Title 10, Chapter 1, Code of Federal Regulations, Part 21, NAK Engineering. Inc. has established and adopted revised procedures to assemble fuel oil lines and climinate the possible defective condition that was found at Mcguire. We have notified each of the affected nuclear stations and furnished copies of the new assembly procedures to the system engineers at McGuire and Brunswick. Through direct communications with the responsible system engineers, we have been advised that the both cites are fully aware of the possible defect or condition and have taken necessary action to examme the afTeeted parts and perform any necessary repairs.

As stated in my letter of Aug. 5,1996, the root cause of the thilure was determined to be an iumlequale tightening value to insure the correct seating of the sleeve that seal the fuelline connection. The revised procedure incorporates specific tightening vahtes, inspection criteria, and acceptance values to determine if the " crimping" of the sleeve is adequate.

1 Should anyone have any questions regarding this condition or corrective action please contact:

s Norman E. Nelson

.N AK Engineering, Inc, 420 AviationBlvd.

Santa Rosa, Ca. 95403 phone: 707-542-9996 fax: 707-542-6666 Sind: rely,

. r-No n E Nc! son Man eer, Quality Assurance

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NAK Engineering, inc.

420 AVIATION BLVD., SANTA ROSA, CA 95403 TELEPHONE: (707) 542 9996 FAX:(707) 542 6666 August 5,1996 Document Control Desk U.S. Nuclear Regulatory Conunission Washington,DC 20555

Dear Sir,

in accordance with the requirements of Title 10, Chapter 1, Code of Federal Regulations, Part 21, N AK Engineering,Inc. hereby notities the Commission of a potential defect or condition in a component of the Nordberg model FS1316HSC Standby Diesel Generator. There exists a potential problem with the fuel injection line assembly which connects the fuel pump to the hQector. .

N AK Engineering, Inc. has supplied these fuelline assemblies to the following sites:

l'TILITY SITE SERIAL N UM RFR(S) MODEL McGuire 1030-1270/1213 FS 1316 HSC l Duke Power Co )

Carolina Power & Light Brunswick 1030 1328/1331 FS 1316 HSC On or about June 20,1996, we were advised of a single leaking fuelline assembly that occurred on McGuire Nuclear Station's Emergency Diesel Generator Unit IB, Cylinder 4R. It was determined that the leak was caused by the fuelline sleeve coming loose which eliminated the fuel connection seal.

f There were no unusual engine noises, temperature. changes, cylinder firing pressure changes noted prior to the fuelline leak. The operator discovered significant fuel spray emitting tirom the fbel pump. l At this time Duke Power initiated a ROOT CAUSE FAILURE ANALYSIS investigation and they determined that the probable cause was inadequate crimping of the ferrule sleeve onto fuelline during assembly. In order to establish corrective action. tests were conducted by Duke Power Co. at their McGuire Nuclear Station's Met Lab to evaluate different torque and tightening l

values to determine the values to achieve optimum " crimping" of the ferrule sleeve. Samples of the same fuel line material, and fermle sleeves, were provided. Duke installed the ferrule sleeves at varying torque values and conducted " pull" tests. It was concluded that the tbelline nut s be tightened 1 1/8-1 1/4 tums past hand tight or 150 ft lbs, of torque to achieve optimum fe A L ,L e~.1 M a ,4 \

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While corrective action procedures have been implemented, the fuel line replacement on cylinder l

number 4R was installed before the corrective action procedures were Enn=1 and before corrective action was taken. It was further believed that this was a unique occurrence l i

l On July 30,1996 the replacement fuel line developed the same leaking problem. Since then ali i fuel lines produced and furnished after July 18,1996 have been assembled using the new torque and tightening techniques. l All fuel line assemblies supplied before July 18,1996, either in service , or in site inventories, should either be returned to NAK Engineering, Inc. for examination and the crimping tightening procedures checked and verified or this work should be done on site. A written procedure will be

!brnished within the next 60 days to the affected sites to accomplish the necessary inspection and repairs.

Should anyone have any questions regardirsthis condition or corrective action please contact:

Norman E. Nelson NAK Engineering, Inc, 420 Aviation Blvd.

Santa Rosa, Ca. 95403 phone: 707-542 9996 fax: 707-542-6666 A copy of this letter will be forwarded to all of the affected sites referenced in paragraph 2 of this letter.

Sinq erely, e

ortnan E Nelson Manager, Quality Assurance