ML23187A472
| ML23187A472 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 06/30/2023 |
| From: | Darrell Roberts Engine Systems |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML23187A472 (1) | |
Text
1111 05:09:06 p.m.
06-30-2023 ENGINE SYSTEMS, INC.
175 Freight Road Rocky Mount, NC 27804 Date:
Company:
Fax Number:
Verification No.:
Reference:
From:
Page:
Dear Sir/ Madam:
TELEFAX June 30, 2023 NRG Operations Center 301/816-5151 301/816-5100 Report No. 10CFR21-0136, Rev. 0 Dan Roberts 1 of 7 Telephone: 252/977-2720 Fax: 252/446-1134 Following this cover is a copy of our report 1 0CFR21-0136, Rev. 0, for a 10CFR21 reportable notification for voltage regulator chassis, P/N's 72-12300-100-ESI, 72-14200-100-ESI, and 72-14000-100-6020.
A copy of this report will be mailed to the NRG Document Control Desk and to our affected nuclear customers.
Should you have questions, please let us know.
Sincerely, Dan Roberts Quality Manager
/sjw Quality Performance With Pride 1 /7
1111 05:09:22 p.m.
06-30-2023 ENGINE SYSTEMS, INC.
175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 Report No.
10CFR21-0136 Rev. 0:
06/30/23 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT:
Voltage Regulator Chassis - Incorrect Bus Bar Installation P/Ns: 72-12300-100-ESI 72-14200-100-ESI 72-14000-100-6020 SYSTEM:
Emergency Diesel Generator CONCLUSION:
Reportable in Accordance With 10CFR21 Prepared By: -.,.-~"""'-l=--'/46'-"--=*...:..._,-,--------
~
Engineering Manager Reviewed By:-----"~:.......,"'-"'--~__;:;,
Quality Assurance Manager Quality Performance With Pride Date:
Date: b /3tJ /23 217
1111 05:09:37 p.m.
06-30-2023 3 /7 Report No.
1DCFR21-0136 Record of Revisions Page:
1 of 1 REV DATE PAGE DESCRIPTION 0
06/30/23 Initial issue.
1111 05:09:45 p.m.
06-30-2023 417 Report No.
Revision:
Date:
Page:
Pursuant to 10 CFR 21.21/dl{4l, ESI is presenting the required information as follows:
(i) Name and address of the individual or individuals informing the Commission.
John Kriesel Engineering Manager Engine Systems Inc.
175 Freight Rd.
Rocky Mount, NC 27804 Dan Roberts Quality Manager Engine Systems Inc.
175 Freight Rd.
Rocky Mount, NC 27804 06/30/23 1 of 4 (ii) Identification of the basic component supplied within the United States which fails to comply or contains a defect.
Voltage regulator chassis with the following part numbers:
72-12300-100-ESI 72-14200-100-ESI
- 72-14000-100-6020 (iii) Identification 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.
Copper bus bars are used at rectifier diode pigtail connections CR1, CR2, CR3, CR4, and CR7 to provide a common connection point for associated wiring to minimize the number of conductors on a single fastener. It is intended for the conductors to clamp directly to the bus bar, thereby maintaining a low resistance conduction path between components. ES/ has determined the bus bars were installed incorrectly whereby the conductors are not clamped in direct contact, resulting in current now through the stainless steel fasteners. This configuration is undesired and will result in unnecessary heat generation which may lead to failure of the connection and therefore failure of the automatic voltage regulator (AVR) assembly. The AVR is relied upon to automatically regulate emergency diesel generator (EOG) terminal voltage. Failure of the AVR would impact ability of the EOG to perform its safety-related function and therefore may impact the nuclear plant's ability to manage safety-related loads during an emergency event.
(v) The date on which the information of such defect or failure to comply was obtained.
May 17, 2023 (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 limited to the following voltage regulator assemblies:
Part Number Customer Customer PO ESI Sales Qty C ofC Date Number Order Shipped 72-12300-100-ESI Constellation Energy - Nine Mile Point 00702105 8003195 2
March 1, 2021 72-14200-100-ESI Avaltec / CFE - Laguna Verde (Div Ill) 1879-20 / 700507054 8003429 2
May 16, 2021 72-14000-100-6020 Avaltec / CFE - Laguna Verde (Div II) 1966 / 700519535 8003506 2
October 25, 2022 Table 1: Voltage Regulator Assemblies Affected
1111 05: 10: 15 p.m.
06-30-2023 5 /7 Report No.
Revision:
Date:
06/30/23 Page:
2 of 4 (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 affected users:
Voltage regulators installed:
Bus bar installation should be corrected immediately by restacking the components to ensure direct contact with all conductors. See section viii below for details.
Voltage regulators in inventory (not installed):
The bus bar installation should be corrected prior to installation. If desired, the customer may perform on site or the voltage regulator chassis may be returned to ES/ for rework.
For ES/:
The shop traveler used for the build-up of voltage regulator chassis will be enhanced to provide additional guidance and a verification will be added to ensure proper installation of the bus bar. This is in process and will be incorporated for future builds prior to shipment.
(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.
Photos below show an example of an incorrectly installed bus bar (photo 1) and one that is correctly installed that ensures proper conduction (photo 2). Photos and figures on the following pages provide additional information.
in direct us bar, no n through
1111 LO 05: 12:49 p.m.
06-30-2023 6 /7 Report No.
Revision:
WIRE LUG DIODE PIGTAIL COPPER BUS BAR Date:
06/30/23 Page:
3 of 4
~1/4-20
~-FLAT WASHER BOLT FLAT WASHER j I FLAT WASHER-NUT~-
LOCK WASHER
\
FLAT W,t,..SHER-
-1 / 4" GLAS TIC Figure 1: Cross Section - Incorrect Bus Bar Install (Note bus bar is not in direct contact with wire lug and diode pigtail)
WIRE LUG\
\
DIODE
/PIGTAIL I
NUT ____Jl ~ i r j COPPER BUS BAR
~--4
,,--1/4-20 BOLT FLAT WASHER
~FLAT WASHEI~
1/4" GLASTIC LOCKWASHER-I FLAT WASH El~-
Figure 2: Cross Section - Correct Bus Bar Install (Note wire lug, diode pigtail, and bus bar stacked in direct contact)
1111 05: 13:09 p.m.
06-30-2023 717 Report No.
Revision:
Date:
Page:
06130123 4 of 4 Figure 3 and photo 3 below show location of the bus bars on the voltage regulator chassis.
0 i::i=='=' '=o::i l@L'G"': ~:_-W*;.1 Figure 3: Outline Drawing - Chassis Upper Half Location of the five bus bars at rectifier diodes CR1, CR2, CR3, CR4, & CR7