ML11215A009
| ML11215A009 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 08/01/2011 |
| From: | Horner T Engine Systems |
| To: | Office of Nuclear Reactor Regulation, NRC Region 1 |
| References | |
| 47112 | |
| Download: ML11215A009 (9) | |
Text
0810112011 U.S. Nuclear Regulatory Commission Operations Center Event Report PagelI Part 21 (PAR)
Event#
47112 Rep Org: ENGINE SYSTEMS, INC Notification Date I Time: 08/01/2011 12:03 (EDT)
Supplier: ENGINE SYSTEMS, INC Event Date I Time: 06/16/2011 12:00 (EDT)
Last Modification: 08/01/2011 Region:
1 Docket #:
City:
ROCKY MOUNT Agreement State:
Yes County:
License #:
State:
NC NRC Notified by: TOM HORNER Notifications:
RAYMOND MCKINLEY R1DO HO Ops Officer: VINCE KLCO RICHARD SKOKOWSKI R3DO Emergency Class: NON EMERGENCY PART 21 GRP EMAIL 10 CFR Section:
21.21 UNSPECIFIED PARAGRAPH PART 21 - EMERGENCY DIESEL GENERATOR FAILED AIR START MOTOR The following information was received by facsimile:
"COMPONENT: Air start motors with friction-clutch inertia drives (not pre-engagement type)
"Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 06/16/11 upon receipt of a failed air start motor from Exelon - Clinton. According to information provided by Clinton Nuclear Plant, they experienced a slow start of an EDG during one of their surveillance runs. Subsequent troubleshooting revealed that one of the air start motors had failed. Specifically, it was found that the starter drive had failed which prevented the air start motor from applying full starting torque to the engine. The inspections performed by Clinton indicated the failed motor had what appeared to be excessive preload applied to the springs of the drive clutch which led to spring roll and fragmentation. Clinton had also supplied six remaining air start motors from their inventory to ESI for evaluation of the drive clutch torque setting. The air starters are Pow-R-Quik type LS-60-RH1 and LS-60-LH1 (where RH and LH designate right hand and left hand rotation respectively).
"The evaluation was concluded on 08/01/11 and determined the air motor failure to be a reportable defect as defined by I OCFR21. The starter drive failure was attributed to excessive torque adjustment of the clutch assembly. This overstressed the clutch disc plates which lead to eventual failure of the friction-clutch inertia drive assembly. Failure of the clutch drive renders the air start motor inoperative. Depending upon the configuration of the engine's starting system, an inoperative air start motor could cause excessive starting times or a start failure.
Either scenario has the potential to prevent the emergency diesel generator from performing its safety related function.
"Clutch torque testing was performed on the six (6) starters returned from Clinton's inventory. [Results indicate
08/01/2011 U.S. Nuclear Regulatory Commission Operations Center Event Report Pae 2 Part 21 (PAR)
Event#
47112 inconsistent clutch settings]. The specified torque setting for the clutch drive is 275-300 ft-lbs. Of the six starters tested, only one was within specification.
"Based on the test data obtained from the six (6) Clinton starters, all previous shipments of air motors with the friction-clutch inertia drive are suspect for having inconsistent clutch drive torque settings."
Affected users of the air start motors that contain friction-clutch inertia drives include the following: Exelon-Clinton, Entergy-Indian Point 3 and PSE&G-Salem.
Engine Systems, Inc Report Number: 10CFR21-0102, Rev. 0.
08-01-11;12:07PM;
- 1 /
7 E
ENGINE SYSTEMS, INC 1220 S. Washington St., Rocky Mount. NC 2780 P.O. Box 1928, Rocky Mount, NC 27802-1928 1
Telephone: 2527g77-2720 Fa=
252/446-1134 TELEFAX Date:
Company:
Fax Number:
Verification No.:
Reference; From:
Page:
August 1,2011 NRC Operations Center 301/816-5151 301/816-5100 Report No. 10CFR21-0102, Rev. 0 Tom Homer 1 of 7 Dear Sir Following this cover is a copy of our report 1 OCFR21-0102, Rev.0, for a 10CFR21 reportable notification on air start motors with friction-clutch inertia drives.
A copy of this report will be mailed to the NRC Document Control Desk and to our affected nuclear customers.
Should you have questions, please let us know.
Sincerely, ENGINE SYSTEMS, INC.
Tom Homer Quality Assurance Manager Quality Performance With Pride
- 2/
7 08-01-11; 12'07PM; ES
,ENGINE SYSTEMS, INC.
175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax 252/446-1134 Report No.
10CFR21-0102 Rev. 0:
08/01/11 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT:
SYSTEM:
CONCLUSION:
Air Start Motors with friction-clutch inertia drives Emergency Diesel Generator - starting air system Reportable in accordance with 1 OCFR21 Prepared By:
Reviewed By:
7 Engineering Manager Date:
Date:.1.zL..
Quality Assurance Manager Quality Performance With Pride
08-01-11;12:07PM;
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7 Report No.
10CFR21-0102 Record of Revisions Page:
1 of 1 REV DATE PAGE DESCRIPTION 0
08/01/11 Initial issue.
08-01-11;12:07PM;
- 4/7 Report No.
10CFR21-0102 Revision:
0 Date:
08/01/11 Page:
1 of 4 COMPONENT:
Air start motors with friction-clutch inertia drives (not pre-engagement type)
SUMMARY
Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 06/16/11 upon receipt of a failed air start motor from Exelon - Clinton. According to information provided by Clinton Nuclear Plant, they experienced a slow start of an EDG during one of their surveillance runs.
Subsequent troubleshooting revealed that one of the air start motors had failed. Specifically, it was found that the starter drive had failed which prevented the air start motor from applying full starting torque to the engine. The inspections performed by Clinton indicated the failed motor had what appeared to be excessive preload applied to the springs of the drive clutch which led to spring roll and fragmentation. Clinton had also supplied six remaining air start motors from their inventory to ESI for evaluation of the drive clutch torque setting. The air starters are Pow-R-Quik type LS-60-RH1 and LS-60-LH1 (where RH and LH designate right hand and left hand rotation respectively).
The evaluation was concluded on 08/01/11 and determined the air motor failure to be a reportable defect as defined by 10CFR21.
The starter drive failure was attributed to excessive torque adjustment of the clutch assembly. This overstressed the clutch disc plates which lead to eventual failure of the friction-clutch inertia drive assembly. Failure of the clutch drive renders the air start motor inoperative.
Depending upon the configuration of the engine's starting system, an inoperative air start motor could cause excessive starting times or a start failure. Either scenario has the potential to prevent the emergency diesel generator from performing its safety related function.
DISCUSSION; The friction-clutch inertia drive is utilized on air starting motors that do not incorporate the pre-engagement feature. In this case, air motor rotation begins before the drive pinion gear meshes with the engine ring gear. The clutch is designed to slip at a prescribed torque setting to absorb the initial torque inrush experienced by the air motor as the pinion and ring gears mesh. This drive assembly was originally manufactured by Facet and was their "K" Type friction clutch. Facet P/N A-3111 was used on clockwise rotation (RH) air starters and P/N A-3236 was used on counterclockwise rotation (LH) air starters. Facet has not supplied starter drives since 2003 and the clutch drives are now supplied by two (2) other manufacturers, ASC (Air Starter Components) and Sun Autoelektrek, The friction-clutch inertia drive is used within the following air start motors supplied by ESI.
Starter Part Number Starter Manufacturer SS81 OGB03R31 Ingersoll-Rand SS81OGB03R31-13B Ingersoll-Rand LS-60-LH1 Pow-R-Quik LS-60-RH1 Pow-R-Quik DS-60-LH1 Pow-R-Quik DS-60-RH1 Pow-R-Quik
08-01-11;12:07PM; Report No.
Revision:
Date:
Page:
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08/01/11 2 of 4 TYPICAL AIR START MOTOR ASSEMBLY I I 4
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EXPLODED VIEW OF FRICTION-CLUTCH INERTIA DRIVE Clutch torque testing was performed on the six (6) starters returned from Clinton's inventory.
Results are listed below and indicate inconsistent clutch settings. The specified torque setting for the clutch drive is 275-300 ft-lbs. Of the six starters tested, only one was within specification.
Serial No.
Pow-R-Quik Clutch Slip Torque Drive Manufacturer Part Number (ft-lbs) 26959 LS-60-LHI 225 Facet 30170 LS-60-RHI 255 Sun Autoelektrek 30737 LS-60-LH1 250 Sun Autoelektrek 39102 LS-60-RH1 260 ASC 39104 LS-60-RH1 380 ASC 39107 LS-60-LHI 275 Sun Autoelektrek CLINTON STARTER DRIVE CLUTCH TORQUE SETTINGS
08-01-11;12:07PM; Report No.
Revision:
Date:
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7 10CFR21-0102 0
08/01/11 3 of 4 AFFECTED USERS:
Based on the test data obtained from the six (6) Clinton starters, all previous shipments of air motors with the friction-clutch inertia drive are suspect for having inconsistent clutch drive torque settings. The table below lists ESI shipments of air start motors that contain friction-clutch inertia drives.
Customer Part Number Serial No.
ESI Sales ESI Ship Date Order Exelon-Clinton DS-60-LH1 28836 3003073 4/4/07 Exelon-Clinton DS-60-LH 1 28837 3003073 4/4/07 Exelon-Clinton DS-60-RH1 28840 3003073 4/4/07 Exeion-Clinton LS-60-LH1 26959 (2) 3003773 9/18/08 Exelon-Clinton LS-60-LH1 26960 3003773 9/18/08 Exelon-Clinton LS-60-LH1 29635 3003773 9/18/08 Exelon-Clinton LS-60-RH1 30170 (2) 3003773 9/18/08 Exelon-Clinton LS-60-RH1 30173 3003773 9/18/08 Exelon-Clinton LS-60-RH1 30176 3003773 9/18/08 Exelon-Clinton LS-60-RH1 30177 3003773 9/18/08 Exelon-Clinton LS-60-LH1 30737 (2) 3003773 9/18/08 Exelon-Clinton LS-60-RH1 31590 (1) 3003773 9/18/08 Exelon-Clinton LS-60-LH 1 31596 3003773 9/18/08 Exelon-Clinton LS-60-RH1 39101 3007171 6/30/10 Exelon-Clinton LS-60-RH1 39102 (2) 3007171 6/30/10 Exelon-Clinton LS-60-RH1 39104 (2) 3007171 6/30/10 Exelon-Clinton LS-60-RHI1 39105 3007171 6/30/10 Exelon-Clinton LS-60-LH 1 39106 3007171 6/30/10 Exelon-Clinton LS-60-LH1 39107 ()
3007171 6/30/10 Exelon-Clinton LS-60-LH1 39109 3007171 6/30/10 Entergy-Indian Pt. 3 SS810GB03R31 SP101021110 3007732 10/26/10 Entergy-Indian Pt. 3 SS81OGB03R31 SP101021111 3007732 10/26/10 Entergy-Indian Pt. 3 SS810GB03R31 SP101021112 3007732 10/26/10 PSE&G-Salem SS81OGB03R31-13B SP030724044 110353 10/9/03 (1): This is the failed starter returned by Clinton (2): These are the six (6) starters returned by Clinton for torque testing.
ESI SHIPMENTS OF SUSPECT AIR START MOTORS
08-01-11; 12:07PM;
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7 Report No.
10CFR21-0102 Revision:
0 Date:
08/01/11 Page:
4 of 4 CORRECTIVE ACTION:
Users should return any of the suspect air start motors in their inventory to ESI for verification of the inertia drive clutch torque setting.
These starters can then be used to replace currently installed starters once the torque setting is verified.
At the next available maintenance interval, users should return any installed starters to ESI for verification of the inertia drive clutch torque setting.
ESI will include clutch torque setting verification in the dedication process for all future shipments of air start motors with friction-clutch inertia drives.