ML11228A086
| ML11228A086 | |
| Person / Time | |
|---|---|
| Site: | Salem, Indian Point, Clinton  |
| Issue date: | 08/01/2011 |
| From: | Woolard S Engine Systems |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML11228A086 (7) | |
Text
nESI NqWV ENGINE SYSTEMS, INC.
175 Freight Road Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 August 1,2011 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001
Subject:
10CFR21 Reporting of Defects and Non-Compliance -
Engine Systems, Inc. Report No. 10CFR21-0102, Rev. 0 Air Start Motors with Friction-Clutch Inertia Drives
Dear Sir:
The enclosed report addresses a reportable notification on air start motors with friction-clutch inertia drives.
A copy of the report has been mailed to our affected nuclear customers.
Please sign below, acknowledging receipt of this report, and return a copy to the attention of Document Control at the address above (or, fax to number 252/446-1134) within 10 working days after receipt.
Yours very truly, ENGINE SYSTEMS, INC.
Susan Woolard Document Control Please let us know if ANY of your mailing information changes - name of recipient, name of company/facility, address, etc. Mark the changes on this acknowledgment form and send to us by mail or FAX to the number above.
RECEIVED:
93 DATE:
Quality Performance With Pride
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(ESI ENGINE SYSTEMS, INC.
14;ijý 175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 Report No.
Rev. 0:
10CFR21-0102 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 10CFR21 Engineering Prepared By:.
Reviewed By:
Manager v
w Date:
8
//q Date: 1z -/-/L Quality Assurance Manager Quality Performance With Pride
Report No.
10CFR21-0102 Record of Revisions Page:
1 of 1 REV [ DATE PAGE I
DESCRIPTION 0
08/01/11 Initial issue.
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 SS810GB03R31 Ingersoll-Rand SS810GB03R31-13B 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
Report No.
Revision:
Date:
Page:
1 OCFR21-0102 0
08/01/11 2 of 4 TYPICAL AIR START MOTOR ASSEMBLY "K" Type Pressure Spring (6)
Plate & Pin Assembly Backing Wase Cluc Body Dis Reann Rin Hea.d' Body Disc (12) 1 Head Screw Head Disc (13)
Screw Shaft Pinion Head Screw Lock Ring S\\
Anti-Drill Spring Meshing Spring J4D~
T~
-Slop Not Pinien Back Stop -...
tpNtRn Back Stop Screw Nu Ring Slop Nut Pin Note: Illuslrations are of lypical parns only.
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-LH1 225 Facet 30170 LS-60-RH1 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-LH1 275 Sun Autoelektrek CLINTON STARTER DRIVE CLUTCH TORQUE SETTINGS
4 Report No.
10CFR21-0102 Revision:
0 Date:
08/01/11 Page:
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.
ESO Sales ESI Ship Date Order Exelon-Clinton DS-60-LH1 28836 3003073 4/4/07 Exelon-Clinton DS-60-LH1 28837 3003073 4/4/07 Exelon-Clinton DS-60-RH1 28840 3003073 4/4/07 Exelon-Clinton LS-60-LH1 26959 (2) 3003773 9/18/08 Exelon-Clinton LS-60-LH 1 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-RH 1 30177 3003773 9/18/08 Exelon-Clinton LS-60-LH 1 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-RH1 39105 3007171 6/30/10 Exelon-Clinton LS-60-LH 1 39106 3007171 6/30/10 Exelon-Clinton LS-60-LH1 39107 (2) 3007171 6/30/10 Exelon-Clinton LS-60-LH 1 39109 3007171 6/30/10 Entergy-Indian Pt. 3 SS81OGB03R31 SP101021110 3007732 10/26/10 Entergy-Indian Pt. 3 SS81OGB03R31 SP101021111 3007732 10/26/10 Entergy-Indian Pt. 3 SS81OGB03R31 SP101021112 3007732 10/26/10 PSE&G-Salem SS81 0GB03R31-13B 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
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.