ML17165A407

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Part 21 Report - Defective Motor Operated Potentiometer
ML17165A407
Person / Time
Site: Palo Verde, Catawba, South Texas  Duke Energy icon.png
Issue date: 06/09/2017
From: Horner T
Engine Systems
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
52798
Download: ML17165A407 (9)


Text

0610912017 U.S. Nuclear Regulatory Commission Operations Center Event Report Pagel Part 21 (PAR) I. Event# 52798 Rep Org: ENGINE SYSTEMS, INC Notification Date I Time: 06/09/2017 17:00 (EDT)

.Supplier: ENGINE SYSTEMS, INC Event Date I Time: 06/08/2017 (EDT)

Last Modification: 06/09/2017 Region: 1 Docket#:

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

State: NC NRC Notified by: TOM HORNER Notifications: LADONNA SUGGS R2DO HQ Ops Officer: BETHANY CECERE JESSE ROLLINS R4DO Emergency Class: NON EMERGENCY PART 21/50.55 REACTORS EMAIL 10 CFR Section:

21.21 (d)(3)(i) DEFECTS AND NONCOMPLIANCE PART 21 REPORT - DEFECTIVE MOTOR OPERATED POTENTIOMETER The following information is excerpted from an Engine Systems, Inc. (ESI) report received via fax:

"Component: Motor operated potentiometer without pre-position feature P/Ns: 72-07900-100-ESI 2-04E-184-103-ESI 2-00G-009-002-ESI "System: Emergency Diesel Generator "Summary:

Engine Systems Inc. (ESI.) began a 10CFR21 evaluation on April 12, 2017 following correspondence with Duke Energy - Catawba Nuclear Plant of a potential issue with a motor operated potentiometer (MOP) supplied by ESI.

During bench testing, Duke was unable .to adjust the cams of the MOP to operate the pre-position feature (also referred to as return-to-center). Further investigation revealed that the MOP supplied to Duke did not contain the desired cam arrangement.

"The evaluation was concluded on June 8, 2017 and it was determined that this issue is a reportable defect as defined by 10CFR21. For installations that rely on the pre-position function to drive generator output voltage to a predetermined setpoint in an emergency event, an incorrect cam arrangement on the motor operated potentiometer could negatively affect the emergency diesel generator [EOG] set's output voltage. This- may prevent the EOG from carrying its safety-related loads in an emergency event.

"Discussion:

0610912017 U.S. Nuclear Regulatory Commission Operations Center Event Report Page 2 A motor operated potentiometer is commonly used in the voltage regulator system of emergency diesel generator sets to allow for local or remote adjustment of generator output voltage. The assembly supplied by ESI was a replacement for pbsolete Portec/NEI part number 72-07900-100. ESI initiated a Supplier Deviation Notification 1

[SON] (Part Number Change) to replace the obsolete part with one that would serve as a functional replacement using the same mounting footprint. To accomplish this, a Basler brand MOP was selected. The "-ESI" suffix was added to designate a modification to the Basler MOP by replacing the standard 2W, open-wound potentiometer with a 3W, precision-wound potentiometer identical to the one used in the original Portee units. The SON indicated that the replacement MOP would have the pre-position feature. Note that the SON would later be revised to include replacements for Cooper-Bessemer part numbers 2-04E-184-103 and 2-00G-009-002 which represented the same Portee part number 72-07900-100.

"The Basler MOP selected by ESI for the assembly was model MOC2103. A review of Basler model MOC2103 indicates that it is not a return-to-center style device and instead contains a standard cam arrangement. Photos on the following page depict the differences between the two cam arrangement styles. ESI inadvertently selected the incorrect model for this application. Reviewing the qualification testing performed by ESI revealed that ESl's testing duplicated the original Portee test procedure (whereby one cam is set to close above setpoint and one cam is set to close below setpoint). However, the testing was shown to be inadequate to fully ensure the return-to-center functionality. Though the cams were properly set above and below setpoint, a further verification that the unit would return to center, even if sufficiently away from setpoint, was not performed. For installations that rely on the preposition function, it is possible that the MOPs supplied by ESI would not return the potentiometer to setpoint.

Since the MOP is used to set output voltage of the emergency diesel generator, the consequences of this issue are that the EOG may not maintain voltage within its required range to support its safety-related loads.

"Root cause evaluation:

ESI selected the incorrect MOP to be used for this assembly. The original MOP used was a Portec/NEI P/N 72-07900-100 which became obsolete in the 1990s. ESI offered a replacement assembly (using the "-ESI" suffix) that included a Basler brand MOP, modified by replacing the factory supplied potentiometer to replicate the original Portee design. The original Portee MOP had the return-to-center feature and Basler offers some models with return-to-center and some without. ESI inadvertently selected the model without return-to-center.

"As a secondary cause, ESl's functional testing did not adequately verify the MOPs ability to return to center. The test procedure has steps to set the cams and limit switches as would be performed for the return-to-center style; however, the testing did not ensure that the cams would return the potentiometer back to the center, regardless of starting position.

[photos submitted with report with following captions:]

"Photo 1: Desired Return-to-Center Cam Arrangement Photo 2: As-Supplied Standard Cam Arrangement Photos 3&4: Return-to-Center Cam Profile & Arrangement Photo 5&6: Standard Cam Profile & Arrangement "Evaluation of previous shipments:

ESI has supplied the replacement MOP from 2009 to 2016 on five (5) separate safety-related orders. A review of each order Indicates that the incorrect MOP was selected for the assembly.

"Affected Customers:

ESI has supplied motor operated potentiometers with the incorrect cam arrangement to the following customers.

"Part Number 72-07900-100-ESI; Customer Duke Energy- Catawba; Customer PO 196046; Qty 6; ESI Serial Numbers 3013905-1.1-1thru6; MOP Serial Numbers H01931980, H01995582, H01995584, H01995585, H01995586, H01995587; C-of-C Date 5/30/2015 "Part Number 72-07900-100-ESI; Customer Dremel/CFE - Laguna Verde; Customer PO 14-0111700427979; Qty 1; ESI Serial Number 3011566-3.1-1; MOP Serial Number H01798043; C-of-C Date 2/13/2015 "Part Number 2-04E-184-103-ESI; Customer APS - Palo Verde; Customer PO 500530279; Qty 3; ESI Serial Numbers 3005695-1.1-1thru3; MOP Serial Numbers: H00958610, H00961219, 333861; C-of-C Date 7/31/2009

0610912017 U.S. Nuclear Regulatory Commission Operations Center Event Report Page3 "Part Number 2-04E-184-103-ESI; Customer APS - Palo Verde; Customer PO 500555659; Qty 3; ESI Serial Num.berrs 3008341-1.1-1 thru 3; MOP Serial Numbers H01151813, H01161548, H01161550; C-of-C Date 212/2012 "Part Number 2-00G-009-002-ESI; Customer South Texas Project; Customer PO 200410; Qty 2; ESI Serial Numbers 3015607-1.1-1thru2; MOP Serial Numbers H02027435, H02027436; C-of-C Date 8/19/2016 "Total Quantity 15 "Corrective Action:

Customers that have installed the motor operated potentiometer must evaluate the impact on their specific system. It may be acceptable to continue to use the MOP if other provisions are in place to ensure the EOG voltage is within an acceptable range for safety-related operation. Credit may also be taken for site acceptance testing following installation of the MOP. If the MOP is deemed acceptable for the application, no further action is necessary.

"For those customers that have determined the MOP is unacceptable for their application and/or would simply rather ensure they have the correct MOP, it may be returned to ESI for warranty replacement. Once a warranty order and Return Goods Authorization (RGA) is issued, supply of safety-related replacement MOP(s) is expected to be complete within 90 days.

"To prevent recurrence of this issue, ESI is implementing a revision to the procurement process for this assembly to update the part number of the MOP utilized. In addition, the dedication inspection and testing activitie's are bein~

revised to ensure testing properly validates the return-to-center feature. This action is currently underway and will be completed prior to any future shipments."

If you have any questions, you may call:

Tom Horner Quality Assurance Manager Tel: (252) 977-2720 ESI Report ID: 10CFR21-0117, Rev. 0, dated 06/09/17

1111 04:56:24 p.m. 06-09-2017 1 /6

. ENGINE SYSTEMS, INC.

Telephone: 252/9n-2720 Fax: 252/446-1134 TELEFAX Date: June 9, 2017 Company: NRC Operations Center Fax Number: 301/816-5151 Verification No.: 301/816-5100

Reference:

Report No. 10CFR21-0117, Rev. 0 From: Tom Homer Page: 1of6

Dear Sir:

Following this cover is a copy of our report 10CFR21-0117, Rev. 0, for a 10CFR21 reportable notification on a motor operated potentiometer without pre-position feature, P/Ns: 72-07900-100-ESI, 2-04E-184-103-ESI, and 2-00G-009-002-ESI.

A copy of this report will be mailed to the NRG Document Control Desk and to our affected nuclear customers.

Should you have questions, pleas~ let us know.

Sincerely, ENGINE SYSTEMS, INC.

Tom Homer Quality Assurance Manager Quality Performance With Pride

1111 04: 56: 39 p.m. 06-09-2017 2/6 ENGINE SYSTEMS, INC.

175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 I

Report No. 10CFR21-0117 Rev. O: 06/09/17 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Motor operated potentiometer without pre-position feature P/Ns: 72-07900-100-ESI 2-04E-184-103-ESl 2-00G-009-002-ESl SYSTEM: Emergency Diesel Generator CONCLUSION: Reportable in accordance with 10CFR21

~ .//MA Prepared By:

a- Engineering Manager Date: __.__'1/_q __.'17._*_

ReviewedB~ bff--

':_? Quality Assurance Manager Date: G-9-17 Quality Performance With Pride

1111 04: 56: 52 p.m. 06-09-2017 3 /6 Report No. 10CFR21-0117 Record of Revisions Page: 1of1 REV DATE PAGE DESCRIPTION 0 06/09/17 Initial Issue.

. 1111 04:57:00 p.m. 06-09-2017 4/6 Report No. 10CFR21-0117 Revision: 0 Date: 06/09/17 Page: 1 of3 Component:

. I Motor operated potentiometer without pre-position feature.

Summary:

Engine Systems Inc. (ESI) began a 10CFR21 evaluation on April 12, 2017 following correspondence with Duke Energy

- Catawba Nuclear Plant of a potential issue with a motor operated potentiometer (MOP) supplied by ESI. During bench testing, Duke was unable to adjust the cams of the MOP to operate the pre-position feature (also referred to as return-to-ce_nter). Further investigation revealed that the MOP supplied to Duke did not contain the desired cam arrangement.

The evaluation was concluded on June 8, 2017 and ft was determined that this issue is a report(!ble defect as defined by 10CFR21. For Installations that rely on the pre-position function to drive generator output voltage to a pre-determined setpoint in an emergency event, an incorrect cam arrangement on the motor operated potentiometer could negatively affect the emergency diesel generator set's output voltage. This may prevent the EOG from carrying its safety:-related loads in an emergency event.

  • Discussion:

A motor operated potentiometer Is commonly used In the voltage regulator system of emergency diesel generator sets to allow for local or remote adjustment of generator output voltage. The assembly supplied by ESI was a replacement for obsolete Portee/NE! part number 72-07900-100. ESI Initiated a Supplier Deviation Notification (Part .Number Change) to replace the obsolete part with one that would serve as a functional replacement using the same mounting footprint. To accomplish this, a Basler brand MOP was selected. The "-ESI" suffix was added to designate a modification to the Basler MOP by replacing the standard 2W, open-wound potentiometer with a 3W, precision-wound potentiometer identical to the one used in the original Portee units. The SON Indicated that the replacement MOP would have the pre-position feature. Note that the SON would later be revised to include replacements for Cooper-Bessemer part numbers 2-04E-184-103 and 2-00G-009-002 which represented the same Portee part number 72-07900-100.

The Basler MOP selected by ESI for the assembly was model MOC2103. A review of Basler model MOC2103 indicates that it is not a return-to-center style devlc.e and instead contains a standard cam arrangement Photos on the following page depict the differences between the two cam arrangement styles. ESI inadvertently sefected the incorrect model for this application. Reviewing the qualification testing performed by ESI revealed that ESl's testing duplicated the original Portee test prqcedure (whereby one cam Is set to close above setpoint and one cam is set to close below setpoint). However, the testing was shown to be inadequate to fully ensure the return-to-center functionality. Tho~gh the cam.s were proper! y set above and below setpolnt, a further verification that the unit would return to center, even if sufficiently away from setpolnt, was not performed. For installations that rely on the pre-

- position function,. ft is possible that the MOPs supplied by ESI would not return the potentiometer to setpoint. Since the MOP is used to set output voltage of the emergency diesel generator, the consequences of this issue are that the EOG may not maintain voltage within Its r.equired range to support its safety-related loads.

Root cause evaluation:

ESI selected the Incorrect MOP ta be used for this assembly. The original MOP used was an Portee/NE! P/N 72-07900"100 which became obsolete in the 1990s. ESI offered a replacement assembly (using the "-ESI" suffix) that included a Basler brand MOP, rnodified by replacing the factory supplied potentiometer ta replicate the original Portee design. The original Portee MOP had the return-t~-center feature and Basler offers some models with return-to-c::enter and some without. ESI inadvertently selected the model without return-to-center.

As a seco*ndary cause, ESl's functional testing did not adequately verify the MOPs ability to return to center. The test procedure has steps to set the cams and llmlt switches as would be performed for the return"to-center style; however, the testing did not ensure that the cams would return the potentiometer back to the center, regardless of starting position.

1111 04 : 57 :40 p.m. 06 2017 5 /6 Report No. 10CFR21-01 17 Revision: 0 Date: 06/09/17 Page: 2 of 3 Photo 1: Desired Return-to-Center Cam Arrangement Photo 2: As-Supplied Standard Cam Arrangement Photos 3&4: Return-to-Center Cam Profile & Arrangement Photo 5&6: Standard Cam Profile & Arrangement

1111 05:00:24 p.m. 06-09-2017 6/6 Report No. 10CFR21-0117 Revision: 0

-Date: 06/09/17 Page: 3 of3 Evaluation of previous shipments:

ESI has supplied the replacement MOP from 2009 to 2016 on five (5) separate safety-related orders. A review of each order indicates that the incorrect MOP was selected for the assembly.

Affected Customers:

ES.I has supplied motor operated potentiometers with the incorrect cam arrangement to the following customers.

ESI Serial MOP Serial C-of-C Part Number Customer Customer PO Qty Number Number Date H01931980 H01995582 H01995584 Duke Energy

  • Catawba 196046 6 3013905-1.1-1thru6 5/30/2015 72-07900-100-ESI H01995585 H01995586 H01995587 Dremel/CFE - Laguna Verde 14-o~ 1noo427979 1 3011566-3.1-1 H01798043 2/13/2015 H00958610 APS - Palo Verde 500530279 3 3005695-1 .* 1-1 thru 3 H00961219 7/3112009 333861 2-04E-184-103-ESI H01151813 APS - Palo Verde 500555659 3 3008341-1.1-1thru3 H0116154B 212/2012 H01161550 2-00G-009.Q02-ESI H02027435 South Texas Project 200410 2 3015607-1.1-1thru2 8/19/2016 H02027436 Total Quantity 15 Table 1: Affected Users Corrective Action:
  • Customers that have installed the motor operated potentiometer must evaluate the Impact on their specific system.

It may be acceptable to continue to use the MOP if other provisions are In place to ensure the EOG voltage is within an acceptable range for safety-related operation. Credit may also be taken for site acceptance testing following Installation of the MOP. If the MOP is deemed acceptable for the application, no further action Is necessary.

  • For those customers that have determined the MOP is unacceptable for their application and/or would simply rather ensure they have the correct MOP, it may be returned to ESI for warranty replacement. Once a warranty order and Return Goods Authorization (RGA) is issued, supply of safety-related replacement MOP(s) Is expected to be complete within 90 days.
  • To prevent recurrence of this issue, ESI is implementing a revision to the procurement process for this assembly to update the part number of the MOP utilized. In addition, the dedication inspection and testing activities are being revised to ensure testing properly validates the return-to-center feature. This action is currently underway and will be completed prior to any future shipments.