ML14197A380
| ML14197A380 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities  |
| Issue date: | 07/14/2014 |
| From: | Bolt T Nuclear Logistics |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| 50272 | |
| Download: ML14197A380 (7) | |
Text
0711412014 U.S. Nuclear Rezulatorv Commission Operations Center Event Report Pav-e I Part 21 (PAR)
Event #
50272 Rep Org: NUCLEAR LOGISTICS INC Notification Date I Time: 07/11/2014 14:15 (EDT)
Supplier: NUCLEAR LOGISTICS INC Event Date / Time: 03/27/2014 (CDT)
Last Modification: 07/11/2014 Region: 4 Docket #:
City:
FT WORTH Agreement State:
Yes County:
License #:
State:
TX NRC Notified by: TRACY BOLT Notifications:
DAVID HILLS R3DO HQ Ops Officer: MARK ABRAMOVITZ PART-21 GROUP EMAIL Emergency Class: NON EMERGENCY 10 CFR Section:
21.21 (d)(3)(i)
DEFECTS AND NONCOMPLIANCE PART-21 NOTIFICATION - ASSEMBLY ERRORS DURING BREAKER REFURBISHMENT The following is a summary of the information provided via facsimile:
"On March 27, 2014, at Exelon-Dresden Station, plant personnel identified that breaker UTC # 1185084 (3B CCSW Pump Breaker) was in the CLOSED condition, but did not indicate CHARGED. The breaker was last CLOSED successfully on March 19, 2014. The breaker charges the closing springs after a CLOSE operation.
"The breaker was OPENED and removed from service on 3/28/14, Dresden notified [Nuclear Logistic, Inc.] NLI on 3/28/14 of the issue and the breaker was returned to NLI on RMA 351022093.
"NLI performed a failure analysis on the breaker. The spring clamp cam 12mm nylon insert lock nut was not properly tightened on either side, resulting in insufficient clamping force of the cam on the jackshaft. In addition to the lock nuts not being sufficiently tightened, the closing springs were installed on the wrong side. There is a left and a right spring as identified by a red mark on the left spring. The left side spring is the shorter spring, and it was installed on the right side. Further evaluation by NLI determined that this may have been a contributing factor to the failure after the closing spring clamp started to move off the jackshaft.
"The presence of the under torque nuts resulted in insufficient clamping force, allowing the clamp to move off the jackshaft. The springs being on the wrong sides began to exert excessive force to the cam as it rotated, and after many operations, it had slipped enough to become partially dislodged from the jackshaft. This bent the spring guide arms, preventing the rotation of the jackshaft to the CHARGED position and did not allow the motor cutoff switch to activate. The result was the breaker did not CHARGE and the motor continued to run until it burned up."
Several AHMG breakers (1200 and 2000A) for Dresden and Quad Cities were refurbished by Nuclear Logistics,
07/14/2014 U.S. Nuclear Regulatory Commission Operations Center Event Report Pare 2 Inc from 2008 to March 2014. At least one breaker was found with insufficient cam nut spring torque and had the two closing springs installed improperly.
Jul,11. 2014 1:12PM No. 9903 P. I SIAZZ NLITM FACSIMILE COVER SHEET DATE: 7/11/2014 TO:
Document Control Desk COMPANY:
Nuclear Regulatory Commission FAX NO.:
301-816-5151 FROM:
Tracy Bolt, Director of Quality Assurance NO. OF PAGES INCLUDING COVER SHEET:
5 MESSAGE:
The attached is a report of potential defect ne i1r 1 PIrk- "71 fliman'u
" N o, Dhl1)' 11751AI1 I3%~S A~..ALt A flAt SEa AA~J~tAZI.L~ZAb flUs L SLtflIA f~I1AW If there are any problems in the transmittal of this document please call 817-284-0077.
NUCLEAR LOGISTICS INC.
WW.an*.co0m 7410 Pebble Drive Fort Worth, Texas 706118 800.448.4124 Phone 817.590.0484 Fax
Jul-11. 2014 1:13PM Jul 1.
214 1:1PMNo.
9903 P. 2 A&AZZ N L IT Date: July 11, 2014 Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555 Part 21 Report No: P21-06172014
Subject:
Report of potential assembly error per 10CFR Part 21 on AMHG refurbished circuit breakers Pursuant to IOCFR 21.21 (d) (3) (ii), AZZINLI is providing written notification of the identification of a potential assembly error. This letter is to notify you of a potential assembly error concerning closing springs on AMHG breakers (1200 and 2000A) refurbished by NLI.
The following information is required per JOCFR 21.21 (d) (4).
(i) Name and address of the individual or individuals informing the Commission.
Tracy Bolt, Director of Quality Assurance Nuclear Logistics, Inc 7410 Pebble Drive Ft. Worth, TX 76118 (ii) Identification of the facility, activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect.
The specific part which fails to comply or contains a defect:
AMIIG-5-350-12 circuit breaker refurbished by NLI. On one identified circuit breaker, the closing spring operating cam nuts did not receive the proper torque, resulting in closing spring malfunction, component damage and spring charging motor failure.
(iii)
Identification of the firm constructing or supplying the basic component which fails to comply or contains a defect.
The AMiG refurbishment was performed by NLI.
Page 1 of 4 NUCLEAR LOGISTICS INC.
www.azz.tem 7410 Pebble Drive Fort Worth, Texas 76118 800.44a-4124 Phone 817.590.0484 Fax
Jul. 11.
2014 1:13PM No, 9903 P. 3 (iv)
Nature of defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.
On March 27, 2014, at Exelon-Dresden Station, plant personnel identified that breaker UTC #
1185084 (3B CCSW Pump Breaker) was in the CLOSED condition, but did not indicate CHARGED.
The breaker was last CLOSED successfully on March 19, 2014. The breaker charges the closing springs after a CLOSE operation.
The breaker was OPENED and removed from service on 3/28/14. Dresden notified NLI on 3/28/14 of the issue and the breaker was returned to NLI on RMA 351022093.
The breaker was supplied October 2008 under client PO 00074944, Release 222.
NLI performed a failure analysis on the breaker. The results of the analysis are summarized as follows:
The spring clamp cam 12mm nylon insert lock nut was not properly tightened on either side, resulting in insufficient clamping force of the cam on the jackshaft.
In addition to the lock nuts not being sufficiently tightened, the closing springs were installed on the wrong side. There is a left and a right spring as identified by a red mark on the left spring. The left side spring is the shorter spring, and it was installed on the right side. Further evaluation by NLI determined that this may have been a contributing factor to the failure after the closing spring clamp started to move off the jackshaft.
The presence of the under torque nuts resulted in insufficient clamping force, allowing the clamp to move off the jackshaft. The springs being on the wrong sides began to exert excessive force to the cam as it rotated, and after many operations, it had slipped enough to become partially dislodged from the jackshaft. This bent the spring guide arms, preventing the rotation of the jackshaft to the CHARGED position and did not allow the motor cutoff switch to activate. The result was the breaker did not CHARGE and the motor continued to run until it burned up.
(v)
The date on which the information of such defect or failure to comply was obtained.
On June 17, 2014, enough information was gathered from the evaluations being performed to determine the reportability of the defect that is the root cause for the event.
Page 2 of 4
Jul. 11.
2014 1:13PM No. 9903 P. 4 (vi)
In the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, supplied for being supplied for, or may be supplied for, manufactured or being manufactured for one or more facilities or activities subject to the regulations In this part.
This is a workmanship issue and not a defect in the design of the breaker. NLI has only supplied this type of refurbished breaker to Dresden and Quad Cities nuclear plants.
The AMI-O ty e breakers refurbished by NLI from 2008 to March of 2014 are listed below.
Plant Name UTC or Serial Number Plant Name UTC or Serial Number Dresden 0000997135 Dresden 0000997126 Dresden 0000997100 Dresden 0000997114 Dresden 0001185094 Dresden 0000997097, Dresden 0002861736 Dresden 0000997122 Dresden 0001192853 Dresden 0000997140 Dresden 0000997107 Dresden 0000997106 Dresden 0000997102 Dresden 0000997099 Dresden 0000997113 Dresden 0000997121 Dresden 0000997130 Dresden 0000997098 Dresden 0001185096 Dresden 0000997125 Dresden 0000997103 Dresden 0002861737 Dresden 0000997108 Dresden 0000997120 Dresden 0000997105 Dresden 0000996976 Dresden 0001185088 Dresden 0001193854 Dresden 0000997093 Dresden 0000996977 Dresden 0000997127 Dresden 0000997137 Dresden 0000997115 Dresden 0000997117 Dresden 0000997110 Dresden 0000997132 Dresden 0001185087 Dresden 0000997138 Dresden 0000997129 Dresden 0000997133 Dresden 0000997111
-QuadCities 0002646678 (10239)
Dresden 0000997134 Quad Cities (10331)
Dresden 0000997119 Quad Cities 0002938736 (10200)
Dresden 0000997104 Quad Cities 0002939006 (10158)
Dresden 0001185065 Quad Cities 0002945867 (10237)
Dresden 0001185089 Quad Cities 0002945868 (10194)
Dresden 0001185064 Quad Cities 0002949774 (10269)
Dresden 0000997101 Quad Cities 0002949775 (10242)
Dresden 0001185091 Quad Cities 0002951358 (10175)
Dresden 0001185085 Quad Cities 0002912833 (10211)
Dresden 0001185084 Quad Cities 0002867433 (10190)
Dresden 0001185092 Quad Cities 0002867434 (10341)
Dresden 0000997095 Quad Cities 0002751776 (10207)
Page 3 of 4
Jul. 1>
2014 1:14PM No. 9903 P. 5 (vii)
The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.
NLI has revised the NLI internal technical procedure, to include the proper torque value of 32 ft lbs (nominal) for the closing spring clamp nuts and proper closing spring orientation verification during assembly and final testing. Training has been administered to the appropriate personnel.
(viii)
Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees, NLI recommends that all breakers identified above be inspected at the next available interval (as determined by the plant) to verify the spring orientation and to verify proper torque of the closing spring clamp nuts.
If the inspection results determine that the springs are not oriented correctly (see Figure 1) but the nuts have been properly torqued, ensure that the cam is fully engaged on the jackshaft (see Figure 2),
the breakers will perform as required.
The spring orientation can be corrected at the next refurbishment interval.
If the lock nuts do not exhibit the proper torque, then the breaker should be evaluated to determine that the cam on the jackshaft is in the proper location (see figure 2) and the proper torque should be
- applied, Figure 1 Correct orientation with the marked spring assembly on the left side of the mechanism.
Correct cain/jackshaft configuration.
Typical for both sides of the mechanism, Please contact me with any questions or comments.
Director of Quality Assurance Page 4 of 4