ML16126A111
| ML16126A111 | |
| Person / Time | |
|---|---|
| Site: | Salem, Wolf Creek, Arkansas Nuclear  |
| Issue date: | 04/29/2016 |
| From: | Toomey M National Technical Systems |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML16126A111 (2) | |
Text
April 29, 2016 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Request for Extension
Reference:
Potential Part 21 on Safety Clip, Siemens Part Number 401-158
Dear Sirs,
National Technical.Systems (NTS) recently submitted a notice for potential Part 21 per the above reference. Scanning electron microscopy of failed Safety Clips indicate the clips failed due to bending fatigue, i.e. cyclic loading, initiating along the inside of the clip. NTS requests an extension of sixty (60) days for performance of additional testing.
Following is the original report detailing the Potential Part 21 notice:
Pursuant to the requirements of 10CFR Part 21, this letter notifies the NRC of a potential Part 21 condition. The subject Safety Clip is used in commercial grade item medium voltage circuit breakers.
The subject circuit breakers are manufactured by Siemens Industry Inc. and are dedicated for use as a Basic Component by National Technical Systems (NTS). Affected circuit breakers are Siemens type 3AF 350 MVA. The safety clip in question is made of a black finish steel and retains the Close Pawl Roller.
During an inspection at Wolf Creek Nuclear Operating Company, it was shown that the subject safety clips were cracked, broken, missing, or degraded after 600 to 850 operations. If the safety clip breaks and falls off and the washers and roller pawl outside bearing and race fall off, then future circuit breaker close operations beyond the next close cycle may not be assured.
National Technical Systems has provided the Siemens Type 3AF 350 MVA circuit breakers to WCNOC, PSEG Nuclear LLC Salem, and Entergy ANO. NTS will contact each utility and recommend that the safety clip part number 401-158 be inspected and replaced with safety clip part number 40115. This safety clip is a yellow zinc plated safety clip of different design, and no known problems exist with this safety clip on different type Siemens circuit breakers dedicated by NTS.
NTS Huntsville
- 7800 Highway 20 West
- Huntsville, AL 35806 * (256) 837-4411
- Fax: (256) 830-2109
- www.nts.com
Thank you for your consideration in this matter 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
April 29, 2016 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Request for Extension
Reference:
Potential Part 21 on Safety Clip, Siemens Part Number 401-158
Dear Sirs,
National Technical.Systems (NTS) recently submitted a notice for potential Part 21 per the above reference. Scanning electron microscopy of failed Safety Clips indicate the clips failed due to bending fatigue, i.e. cyclic loading, initiating along the inside of the clip. NTS requests an extension of sixty (60) days for performance of additional testing.
Following is the original report detailing the Potential Part 21 notice:
Pursuant to the requirements of 10CFR Part 21, this letter notifies the NRC of a potential Part 21 condition. The subject Safety Clip is used in commercial grade item medium voltage circuit breakers.
The subject circuit breakers are manufactured by Siemens Industry Inc. and are dedicated for use as a Basic Component by National Technical Systems (NTS). Affected circuit breakers are Siemens type 3AF 350 MVA. The safety clip in question is made of a black finish steel and retains the Close Pawl Roller.
During an inspection at Wolf Creek Nuclear Operating Company, it was shown that the subject safety clips were cracked, broken, missing, or degraded after 600 to 850 operations. If the safety clip breaks and falls off and the washers and roller pawl outside bearing and race fall off, then future circuit breaker close operations beyond the next close cycle may not be assured.
National Technical Systems has provided the Siemens Type 3AF 350 MVA circuit breakers to WCNOC, PSEG Nuclear LLC Salem, and Entergy ANO. NTS will contact each utility and recommend that the safety clip part number 401-158 be inspected and replaced with safety clip part number 40115. This safety clip is a yellow zinc plated safety clip of different design, and no known problems exist with this safety clip on different type Siemens circuit breakers dedicated by NTS.
NTS Huntsville
- 7800 Highway 20 West
- Huntsville, AL 35806 * (256) 837-4411
- Fax: (256) 830-2109
- www.nts.com
Thank you for your consideration in this matter 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