ML19087A252

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Engine Systems, Inc. - 10 CFR 21 Reportable Notification on Excitation Transformers for Vickers Voltage Regulator System
ML19087A252
Person / Time
Site: Monticello, Surry, Turkey Point  NextEra Energy icon.png
Issue date: 03/21/2019
From: Darrell Roberts
Engine Systems
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
10CFR21-0124, Rev. 0
Download: ML19087A252 (1)


Text

1111 02:52:15p.m. 03-21-2019 1 /8 ENGINE SYSTEMS, INC.

175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 TELEFAX Date: March21,2019 Company: NRC Operations Center Fax Number: 301/816-5151

. Verification No.: 301/816-5100

Reference:

. Report No. 10CFR21-0124, Rev. O From: Dan Roberts Page: 1 of 8

Dear Sir:

Following this cover is a copy of our Report 10CFR21-0124, Rev.O, for a 10CFR21 reportable notification on excitation transformers for Vickers voltagf;l regulator system. This is a follow-up to our interim report 10CFR21-0124-INT, Rev. 0 issued on January 24, 2019. Our evaluation determined that the deviation is reportable in accordance with 10CFR21 Part 21.

A copy of the report will be mailed to the NRC Document Control Desk.

Should you have questions, please let us know.

Sincerely, ENGINE SYSTEMS, iNC.

/1~

Dan Roberts Quality Manager Quality Performance With Pride

1111 02:52:30 p.m. 03-21-2019 2/8

.@'j) ENGINE SYSTEMS, INC.

175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 Report No. 10CFR21-0124 Rev. O: 03/21/19 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Excitation Transformers for Vickers Voltage Regulator System Part Number Device Description 8408213-ESI Power Current Transformer (PCT) 8408218-ESI Saturable Reactor (Reactor) 8411387-ESI* Excitation Power Transformer {EPT)

SYSTEM: Emergency Diesel Generator - Voltage Regulator System CONCLUSION: Reportable in Accordance with 10CFR21

<:Jk~ .** .3/2d 11 Prepared By: Date:

ngiheering Manager Reviewed By: ~-~ Date: 3/P.1/Jq Quality Assurance Manager Quality Performance With Pride

1111 02:52:45 p.m. 03-21-2019 3/8 Report No. 10CFR21-0124 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION 0 *03/21/19 Initial issue.

i

1111 02:52:53 p.m. 03-21-2019 4/8 Report No .. 10CFR21-0124 Revision: 0 Date: 03/21/19 Page: 1 of 2

SUMMARY

On January 24, 2019, Engine Systems Inc. {ESI) Jss.ued interim report 10CFR21-0124-INT, rev.O regarding an

  • Identified deviation for which ESI was unable to complete an evaluation within the 60-day requirement. Per the Interim report, ESI committed to complete the evaluation by March 22, 2019. The evaluation Is now complete and the deviation is determined to be reportable in accordance with 10CFR Part 21.

Pursuant to 10 CFR 21.21{d)(4), ESI Is presenting the required information as follows:

(I) Name and address of the Individual or individuals Informing the Commission.

John Kriesel Dan Roberts Engineering Manager Quality Manager Engine Systems Inc. Engine Systems Inc.

175 Freight Rd. 175 Freight Rd.

Rocky Mount, NC 27804 Rocky Mount, NC 27804 (II) Identification of the basic component supplled within the United States which falls to comply or contains a defect. *

  • Excitation transformers of the following part numbers:

Part Number Device Description 8408213-ESI Power current Transformer (Pen 8408218-ESI Saturab/e Reactor (Reactor}

.8411387-ESI Excitation Power Transformer (EPTI (iii) ldentificatlpn of the firm supplying the basic component which fails to comply or contains a defect.

Engine Systems Inc. (ES/)

(iv) Nature of the defect or failure to comply and the safety hazard which Is created or could be created by such defect of failure to comply.

Part Number Device Description of Defect 8408213-ESI PCT Insufficient care r,a,::,.

8408218-ES/ Reactor Differences In coll windlna and core lamination from orlainal desian.

8411387-ESI EPT Incorrect no/artty.

Each of the devices listed above provide a specific function within the static exciter of a Vickers voltage regulator system. The exciter suppl/es DC excitation current to the generator field based on input from the voltage regulator. Failure of any one of the components to perform correctly will negatively Impact excitation current supplied to the generator field which In tum directly affect$

generator output. Therefore, failure of any one of the components may prevent the emergency diesel generator from carrying its associated safety-related loads.

See Attachment 1 for additional discussion.

(v) The date on which the Information of such defect or failure to comply was obtained.

December 6, .2018 (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.

The list of customers to whom ES/ has supplied the transformers as dedicated, safety-related devices Is listed In the table on page 2.

  • 1111 02:53:29 p.m. 03-21-2019 5/8 Report No. 10CFR21-0124 Revision: a Date: 03/21/19 Page: 2of2 Part Number. Device Customer Cµstomer PO# Qty ESIOrder C*of-C Date Florida Power & Ught -

Turkey Point 02318321/00032 3 3012629 01/06/2015 8408213-ESI PCT Northern states Power Company*

Monticello 4000002229 9 8002765 08/30/2018 Dominion Virginia Power -

Surry Power Station 45936798 6 3010193 07/31/2013 Florida Power & Ughl -

Turkey Point 02313521/00013 1 3010993 10/18/2013 8408218-ESI Reactor Florida Power & Ught - 04/30/2014 (qty 3) 02318321/00032 5 3012629 Turkey Point OB/01/2014 (qty 2)

Northern States Power Company-Monticello 4000002229 18 8002765 07/30/2018 Dominion Virginia Power-Surry Power Station 4500013104 1 3010356 08/07/2013 Florida Power & Light*

Turkey Point 02313521/00013 1 3010993 10/18/2013 8411387.,l:SI EPT Florida Power & Light*

02318321/00032 2 3012629 08/01/2014 Turkey Point BMPC-KAPL 112732-18 1 3017417 12/27/2017 Northam States Power Company. g Monticello 4000002229 8002765 08/31/2018 Table 1: Ust ofAffected Customers (vii) The corrective action which has been, Is being, or will be taken; the name of the lndlvldual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.

PIN 8408213-ESI fPCTI:

Return to ES/ for rework. The PCT requires additional insulating material to Increase the core gap.

PIN 8408218-ESI (Reactor}:

Return. to ES/ for replacement.

PIN 8411387-ESI fEPD:

Return to ES/ for rework to have EPT primary terminal markings (H1 & H2) re-labeled.

ES/ w/11 /mplement inspection and test requirements to ensure additional critical characteristics identified during this evaluation process are properly verified. The dedication package revisions to include these characteristics Is expected to be complete within 60 days but in all cases prior to sh!pment ofany new or reworked transformers of the above part numbers.

(viii) Any advice related to the potential 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.

See Attachment 1 for additional discussion.

1111 02:54:01 p.m. 03-2.1-2019 6/8 Report No. . 10CFR21-0124 Revision: 0 Attachment 1 Page: 1 of3 ATTACHMENT 1 ADDITIONAL DISCUSSION ON EXCITER TRANSFORMERS (MAGNETICS)

The Vickers voltage regulator system was original equipment supplied with many of the nuclear EDGs, primarily 1960s and 1970s vintage units. The Vickers exciter components went out of production approximately 20 years ago and ESI began a reverse engineering Initiative In 2012 to offer customers replacements for their existing magnetics. This activity was performed in collaboration with a transformer manufacturer using available drawing and design Information and disassembly Inspection of sample units of the original design. The new transformer part numbers were given a "-ESln suffix to denote they are made by a different manufacturer but kept the original base part number to maintain traceablllty to the original application.

ESI was notified on December 6, 2018 of a potential issue with exciter magnetics supplied to Monticello Nuclear Generating Plant. During system* testing performed by Monticello at another vendor facillty, Issues with the static excitation system were Identified which prevented proper control of the. generator field current. This prompted the 10CFR21 evaluation that ultimately lead to this 10CFR21 report. Additional tests and inspections performed throughout ESJ's evaluation determined that while many of the characteristics between the old and new magnetics are the same, key differences exist that caused the performance anomalies Identified during Monticello system testing.

Within the voltage regulator system, the magnetics supply DC excitation current to the generator field based on Input from the voltage regulator. A typical schematic Is shown in Figure 1 below. The three components in question are the excitation power transformers (identified as EPT1, EPT2, & EPT3), power current.

transformers (Identified as PCTA, PCTB, & PCTC) and saturable reactors (Identified as L1 through L6). The Issues with each component, as well as outtlne drawings, are contained on the following pages.

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  • n Figure 1: Typical Vickers Voltage Regulator System Sc:hematlc

1111 02:54:49 p.m. 03-21-2019 7/8 Report No. 10CFR21-0124 Revision: 0 Attachment 1 Page: * - 2of3 Excitation Power Transformer Three single-phase EPTs are wye connected on the primary and delta connected on the secondary. Per the system design, EPT primary H1 should have the same polarity of EPT secondary X1. Contrary to this requirement, EPT primary H1 has the same polarity as secondary X3.

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Figure 2: EPT OuUlne Drawing_

Power Current Transformer Three single-phase PCTs provide a secondary voltage proportional to the primary current. The PCT, in conjunction with the EPT, provide the power to support generator field excitation. Certain characteristics of the PCT secondary voltage f!re determined by the magnitude of an air gap in the core construction. It has been determined the PCT supplied by ESI has a gap of 0.030" whereas the_ original design PCT has a gap of 0.080".

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Figure 3: PCT Outline Drawing

1111 02:55:22 p.m. 03-21-2019 8/8 Report No. 10CFR21-0124 Revision: .o Attachment 1 Page: 3of3 Saturable Reactor In conjunction with a rectifier diode, the saturable reactor acts as a magnetic amplifier. Six of these magnetic amplifier assemblies are used in the rectifier bridge of the voltage regulator system. The reactor receives a bias and control current from the voltage regulator which varies the level of saturation In the reactor core.. As

  • the level of saturation changes, the reactor Impedance varies which Increases or decreases generator field voltage. It has been determined the saturable reactor supplied by ESI has coll winding and core winding differences from the originally supplied reactor that may cause subtle, but undesired performance differences.

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  • Figure 4: Reactor Outline Drawing