ML17286A024

Part 21 on Siemens 5-3AF-GER-350-1200-78 & 5-3AF-GEU-350-1200-78 Circuit Breakers

ML17286A024
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/11/2017
From:	Toomey M National Technical Systems
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML17286A024 (1)

Text

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NTS October 11, 2017 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Part 21 on Siemens 5-3AF-GER-350-1200-78 & 5-3AF-GEU-350-1200-78 Circuit Breakers

Dear Sirs,

Pursuant to the requirements of 10 CFR Part 21, this letter is hereby provided to you as notification of a Part 21 condition. The subject equipment are Siemens Types 5-3AF-GER-350-1200-78 and 5-3AF-GEU-350-1200-78 Medium Voltage Circuit Breakers that NTS has dedicated for use as a basic component. NTS has supplied these circuit breakers to Entergy - Arkansas Nuclear One only. The Circuit Breakers have experienced a failure to close condition as a result of degraded Siemens 40-901-495-003 yellow closing springs. These models of circuit breakers were manufactured during the limited timeframe of 1996-2000 and utilize Westinghouse/Cutler-Hammer WL-3558 vacuum interrupters paired with the yellow closing spring. This is the only combination that has exhibited a failure to close condition after approximately 20 years.

NTS/Siemens recommends replacement of the yellow closing spring with Siemens 18-763-442-252 yellow/red closing springs.

Thank you and if you have any questions, please contact NTS' Senior Director of Nuclear Engineering and Test Services, Tom Brewington at (256) 716-4512 or email at tom.brewington@nts.com.

Sincerely,

• -*****,;.,.:,... ~--~ ... ---~---

Megan Toomey Sr. Contracts Manager NTS Huntsville NTS Huntsville

• 7800 Highway 20 West

• Huntsville, AL 35806 * (256) 837*4411

• Fax: (256) 830*2109

• www.nts.com