ML12283A244

Part 21 - Temperature Switch Potentially Shipped Without Set Screw

ML12283A244
Person / Time
Site:	Watts Bar, Arkansas Nuclear, Clinton, LaSalle
Issue date:	10/05/2012
From:	Horner T Engine Systems
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
48382
Download: ML12283A244 (7)

Text

1010512012 U.S. Nuclear Regulatory Commission OperationsCenterEvent Report Page I Part 21 (PAR) Event# 48382 Rep Org: ENGINE SYSTEMS, INC Notification Date / Time: 10/05/2012 10:33 (EDT)

Supplier: DETROIT SWITCH Event Date / Time: 04/02/2012 (EDT)

Last Modification: 10/05/2012 Region: 1 Docket #:

City: ROCKY MOUNT Agreement State: Yes County: License #:

State: NC NRC Notified by: TOM HORNER Notifications: KATHLEEN O'DONOHUE R2DO HQ Ops Officer: DONG HWA PARK DAVE PASSEHL R3DO Emergency Class: NON EMERGENCY DALE POWERS R4DO 10 CFR Section: PART 21 GROUP EMAIL 21.21 (d)(3)(i) DEFECTS AND NONCOMPLIANCE PART 21 - TEMPERATURE SWITCH POTENTIALLY SHIPPED WITHOUT SET SCREW "Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 9/18/2012 after an ESI test technician found a set screw in one of the oil bath stations of the temperature test fixture. After evaluating all components that were tested on the fixture, it was determined that this set screw is the same length, thread size and style as the set screw utilized in the EMD/Detroit temperature switches to lock the differential adjustment screw. The other components tested on the fixture did not contain such a set screw. Either an extra set screw was inside a temperature switch and it fell into the test fixture oil bath when the test technician removed the switch cover; or, the test technician dropped the set screw after removing it from a temperature switch to adjust the differential setting of the switch. If the latter occurred, then the potential exists that a temperature switch was shipped without the differential adjustment screw locked and therefore the switch settings could drift over-time from exposure to vibration on the EDG skid. ESI has identified the time period in which this could have occurred to be 4/2/2012 to 9/18/2012. The suspect temperature switches are EMD parts manufactured by Detroit Switch. These are located in the engine cooling water and lube oil systems for low standby lube oil temperature alarm, high coolant temperature alarm/shutdown and coolant immersion heater control applications.

"The evaluation was concluded on 10/3/2012 and it was determined that this issue is a reportable defect as defined by 10CFR21. If a switch applied in the immersion heater control application experiences significant setpoint drift, it is possible that the standby temperatures of the lube oil and coolant systems may be degraded enough to affect the start time of the diesel generator.

"All affected users should inspect the suspect switches for presence of the set screw at their earliest convenience.

If the set screw is missing, the temperature switch should be returned to ESI for rework."

Received at: 10/05/2012 10:32 10-05-12; 10:43AM; # 1/ 6 ENGINE 175 Freight SYSTEMS, INC.

Road Telephone: 252/977-2720 Rocky Mount. NC 27804 Fax: Z52/446-1134 TELEFAX Date: October 5, 2012 Company: NRC Operations Center Fax Number: 301/816-5151 Verification No.: 301/816-5100

Reference:

Report No. 10CFR21 -0106, Rev. 0 From: Tom Homer Page: 1 of 6

Dear Sir:

Following this cover is a copy of our report 10CFR21 -0106, Rev.0, for a 10CFR21 reportable notification on a EMD (Detroit Switch) temperature switch -

potential missing set screw.

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

10-05-12;10:43AM; # 2/ 6 (131 ENGINE SYSTEMS, INC.

175 Freight Road, Rocky Mount, NC 27804 Telephone; 252/977-2720

. Fax: 252/446-1134 Report No. 10CFR21l-0106 Rev. 0: 10/4/12 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: EMD (Detroit Switch) temperature switch - potential missing set screw SYSTEM: Emergency Diesel Generator CONCLUSION: Reportable in Accordance With 10CFR21 Prepared By:- Date: /O7#/AZ

,Z Engineering Manager Reviewed By: Date: ie-'AI.

Quality Assurance Manager Quality Performance With Pride

1. 3/ 6 10-05-12;10:43AM; Report No, 10CFR21-0106 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION 0 10/4/12 Initial issue.

10-05-12;10:43AM; # 4/ 6 Report No, 10CFR21-0106 Revision: 0 Date: 10/4/12 Page: 1 of 3 COMPONENT; EMD (Detroit Switch) temperature switch - potential missing set screw

SUMMARY

Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 9/18/2012 after an ESI test technician found a set screw in one of the oil bath stations of the temperature test fixture. After evaluating all components that were tested on the fixture, it was determined that this set screw is the same length, thread size and style as the set screw utilized in the EMD/Detroit temperature switches to lock the differential adjustment screw. The other components tested on the fixture did not contain such a set screw. Either an extra set screw was inside a temperature switch and it fell into the test fixture oil bath when the test technician removed the switch cover; or, the test technician dropped the set screw after removing it from a temperature switch to adjust the differential setting of the switch. If the latter occurred, then the potential exists that a temperature switch was shipped without the differential adjustment screw locked and therefore the switch settings could drift over-time from exposure to vibration on the EDG skid. ESI has identified the time period in which this could have occurred to be 4/2/2012 to 9/18/2012. The suspect temperature switches are EMD parts manufactured by Detroit Switch. These are located in the engine cooling water and lube oil systems for low standby lube oil temperature alarm, high coolant temperature alarm/shutdown and coolant immersion heater control applications.

The evaluation was concluded on 10/3/2012 and it was determined that this issue is a reportable defect as defined by 10CFR21. If a switch applied in the immersion heater control application experiences significant setpoint drift, it is possible that the standby temperatures of the lube oil and coolant systems may be degraded enough to affect the start time of the diesel generator.

Discussion:

The set screw found in the temperature test fixture oil bath is 1/8" long with #6-32 threads. This is the same length, thread size and style as the set screw used in EMD/Detroit temperature switches to lock the differential adjustment screw.

TYPICAL EMD/DETROIT TEMP SWITCH SET SCREW LOCATION (shown with cover removed)

10-05-12;10:43AM; # 5/ 6 Report No. 10CFR21 -0106 Revision: 0 Date: 10/4/12 Page: 2 of 3 Affected users and shipments:

A listing of the suspect temperature switches and the corresponding customer information for each is provided in Table 1.

Part ESI SIN SYh Customer Customer PO Number date 9544836 1 3008686-1.1-1 5/31/12 WVA-Watts Bar 00001690/280405 954483 2 3008457-1.11 5/24/12 Entergy-ANO 10314337 9544836 2 3008457-1.1-2 9544837 1 3009631 6/21/12 Exelon-Lasalle 000703, rIse 12295 9544841 .2 8002029-1.1-1 8002029-4,1-1 9/6/12 Exelon-Clinton 000703, rise 12257 3010254-1.1-1 9544841 2 30102541,1-2 3010254-1.1 -2 9/6112 TVA-Watts Bar 400001690/36116 9544842 1 3009662-1.1-1 9/7/12 Exelon-Clinton 000703, rise 12299 9544842 2 I I3009552-1.1-2II 3009552-1.1-1 6/25/12 PGS-Cofrentes N2012/036 TABLE 1: SUSPECT TEMPERATURE SWITCHES Impact on Operability:

Part number 9544841 is used to control the coolant immersion heater which maintains the temperature of the preheat system at the appropriate temperature to ensure fast starting of the EDG. For this temperature switch, setpoint drift could impact the starting time of the diesel generator; therefore, the ability of the diesel generator to perform its safety related function could be impacted Part number 9544842 performs an alarm only function for low standby oil temperature. Setpoint drift of this switch will not impact the ability of the diesel generator from performing its safety function.

Part number 9544836 has been utilized for either an alarm only function for high coolant temperature or for high coolant temperature shutdown (depending upon the vintage of the unit).

The shutdown function is bypassed during emergency mode operation; therefore, setpoint drift of this switch will not impact the ability of the diesel generator from performing its safety function.

Part number 9544837 performs a high coolant shutdown function. The shutdown function is bypassed during emergency. mode operation; therefore, setpoint drift of this switch will not impact the ability of the diesel generator from performing its safety function.

Only part number 9544841 has been determined to have the potential to impact the safety related operability of the diesel generator; however, all suspect temperature switches are included in this notification to alert users of the potential for setpoint drift.

10-c 0b-i2; iu:f*JAM; # 6/ 6 Report No. 100FR21-0106 Revision: 0 Date: 10/4/12 Page: 3 of 3 Corrective action:

All affected users should inspect the suspect switches (see Table 1) for presence of the set screw at their earliest convenience. If the set screw is missing, the temperature switch should be returned to ESI for rework.

To inspect the switch, perform the following:

1. Loosen the screw located in the center of the temperature switch cover.

2. Remove the cover, the mounting screw and cover gasket will remain attached to the cover.

3. Look behind the insulator to access the differential adjust screw.

4. Verify that set screw is installed.

a. If installed, re-install the cover; temperature switch is acceptable.

b. If not installed, return the temperature switch to ESI for rework.

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