ML20065G467

Part 21 Rept Re Failure of Support Studs on Discharge Piping Bracket to Turbocharger That Provide Support for Air Inlet Housing

ML20065G467
Person / Time
Site:	Prairie Island
Issue date:	04/01/1994
From:	Fratianne S COLTEC INDUSTRIES, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-94 NUDOCS 9404120288
Download: ML20065G467 (2)

Text

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j ColtecIndustries fjf,I"yf,,7*

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701 Lawton Avenue J Beloit, Wisconsin 53511-5492

@' Telephone: 608/364-4411 Telecopier: 608/364-0382 l

01 April 1994 l Document Control Desk United States Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Air Piping Support Stud. Turbo End 10 CFR Part 21 Notification-93-005 To whom it may concern:

On 16 September 1993, Northern States Power Company's Prairie Island Nuclear Generation Plant notified Fairbanks Horse Engine Division, via Nonconforming Item Report No.:'0900, of the failure of-two(2) support studs (FHED P/N 16100711) on the Discharge Piping Bracket to the Turbocharger that provide support for the Air Inlet' Housing.

The subject studs are manufactured by Fairbanks Horse Engine Division, and are made from cold finished carbon steel: AISI C1117 material equal to Grade 2. The design of the part dates back to 1962, and are in use on all 12 cylinder turbo parallel units shipped to date; these parts have not been previously reported as a service problem.

The stud and bracket assembly is used for support and control of vibration only. The failure mode'may be caused by excessive torque, or misalignment during the life of' this component; the design is not in question'. l l

The results of the engineering evaluation pursuant to this issue indicates that this condition does not constitute a substantial safety hazard as defined.

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However, affected utilities with 12 cylinder turbo I parallel units should pay special attention to the l alignment, and torque conditions associated with the l installation of the stud and bracket assembly during, )

future maintenance and inspection activities.

Sincerely,

/ .~-

Scott A. F atianne '

Quality Assurance Hanager.

Supplier and Systems Quality cc: W. Hartin T. Stevenson Northern States Power Company File 93-005 l

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