ML25317A676
| ML25317A676 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 10/15/2025 |
| From: | Darrell Roberts Engine Systems |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 57988 | |
| Download: ML25317A676 (1) | |
Text
2025/10/15 09:02:40 Engine Systems Inc 175 Freight Road Rocky Mount NC 27804 FROM ~ TO Name Susan Woolard Phone Fax 7134351000 3018165151 E-mail Susan Woolard@kirbycorp com NRC Operations Center Sent 10/15/25 at 9 02 40 AM 6 page(s) (including cover)
Subject Report No 10CFR21-0139, Rev 0 Comments See attached
2025/10/15 09:02:40 2 /6 ENGINE -Y - TEMS INC.
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175 Freight Road Telephone 252/977-2720
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Rocky Mount NC 27804 Fax. 252/4464 134 TELEFAX Date:
October 15,2025 Company:
NRC C'--:-. :':':Center Fax Number:
301/816=5151 Verification No.:
301/816-5100
Reference:
Report No. 10CFR21-0139, Rev. 0 From:
Dan Roberts
Dear Sir / Madam:
F -11=.' I:.,7 this cover is a copy of our report 10CFR21-0139, Rev. 0, foral-2 7121 reportable notification Tora Power :: i Potentiometer with loose relay sockets, P/N ES150258.
A copy of the report will be mailed to the NRC Document Control Desk and to our affected nuclear customer, Should you have questions, please let us know.
7*
ENGINE SYSTEMS, INC.
y Dan Roberts Quality Performance With Pride
2025/10/15 09:02:40 3 /6 1
ENGINE SYSTEMS INC.
3-
- 175 Freight Road, Rocky Mount, NC 27804 Telephone 252/977-2720 Fax 252/446-1134 Report No. 10CFR21-0139 Rev. 0:
10/15/25 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Power Driven Potentiometer with loose relay sockets P/N ES150258 SYSTEM:
Emergency Diesel Generator CONCLUSION: Reportable in Accordance With 10CFR21 Prepared By Date: _l.,0/5 21-L; 7 --/Manager--
Reviewed By:
11 AU Date: / 0 -
19 -15 ell!'1;2111'11*21:2~2~211=11~~'~'r-----5!~-!r;11;~~M-Quality Performance With Pride
2025/10/15 09:02:40 4 /6 Report No 10CFR21-0139 Record of Revisions Page 1 ofl REV DATE PAGE DESCRIPTION 0
10/15/25 Original Issue.
2025/10/15 09:02:40 5 /6 Report No 10CFR21-0139 Revision 0
Date 10/15/25 Page 1 of 2 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 Dan Roberts John Knesel Quality Manager Engineering 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 supplied within the United States which fails to comply or contains a defect Power Driven Potentiometer (PDP), P/N ES150258 (iii) Identification of the firm supplying the basic component which fails to comply or contains a defect Engine Systems Inc (ESI)
(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 Relay sockets used to retain relays Kl and K2 on P/N ESI 50258 were found to have low retention force Thefunctionofthe Kl and K2 relaysinthisdeviceistoswitch polanty tothemotorofthe PDP to change direction of rotation when an external raise or lowercommand is given The motor within the PDP rotates a potentiometer that provides a resistance input to the emergency diesel generatofs automatic voltage regulator (AVR) This resistance is used to adjust the terminal voltage setpoint of the generator Without both relays installed, the raise and lower function of the PDP is inoperable, thus preventing adjustment of the generator output voltage The safety-related function of the PDP is to maintain the potentiometer resistance at a predetermined value (-preposition>>) that corresponds to the desired generator voltage setpoint when operating during an emergency event There is a scenatio where the PDP is adjusted to a value other than the normal voltage setpoint and if the Kl or K2 relays were to dislodge during a subsequent emergency event, the PDP would not return to its preposition setpoint and therefore the generator terminal voltage would not return to its desired voltage setpoint In this scenatio, ability of the EDG to carry its safety-related loads could be impacted (v) The date on which the information of such defect or failure to comply was obtained August 27,2025 (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 extent of condition is qty 2 devices supplied to Prairie Island that contained suspect relay sockets from same date code Customer I ES/ Sa/es I Part Number \\
Customer
\\ Serial Numbers 1 ESI C-of-C Date 1 PO Order Ordered Northern States 3024999-1 1-1 Power Company 4000032504 3024999 ESJ50258 January 13, 2025 3024999-1 1-2
- Praine Island
2025/10/15 09:02:40 6 /6 Report No 10CFR21-0139 Revision 0
Date 10/15/25 Page 2 of 2 (vii) The corrective action which has been, is being, or will be taken, the name of the individual or organization responsible for the action, and the length of time that has been or will be taken to complete the action For Prairie Island*
Of thetwoserial numbers affected, 3024999-1 1-2 has been returned to ESI and thedevice has been reworked by replacing both relay sockets and adding relay hold down springs Serial number 3024999-1 1-1 should beevaluated for thesame condition and returned to ES for the same rework EgLESL The PDP designhasbeen updatedtoaddrelayholddownsprings forpositiverelay retention Part number ES150258 has been made obsolete and replaced with part number ES150258A to designate theaddition of relay hold downsprings Thischange occurred on September 24, 2025 (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 Representative images of the socket and relay used in ESI 50258 are provided below to aid in component identification Relay Socket 1,3.94 + t P Relay 4£. 44:
N
£-1 '1 l 12