ML26015A114
| ML26015A114 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 01/15/2026 |
| From: | Bonifanti M Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| EN 58091, CCN 26-01 | |
| Download: ML26015A114 (0) | |
Text
CCN: 26-01 10 CFR 21.21(d)(3)(ii)
January 15, 2026 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station (PBAPS) Units 2 and 3 Subsequent Renewed Facility Operating License No. DPR-44, DPR-56 NRC Docket No. 50-277, 50-278
Subject:
10 CFR 21 Notification for Emergency Diesel Generator Cylinder Chrome Delamination RE:
EN 58091 In accordance with Title 10 of the Code of Federal Regulations (10 CFR) Part 21, Reporting of Defects and Noncompliance, Peach Bottom Atomic Power Station is providing the required written notification of a defect in a basic component associated with Fairbanks Morse Emergency Deisel Generator Cylinder liner assembly supplied by Fairbanks Morse Defense. The enclosure to this letter provides the information required in 10 CFR 21.21 (d)(4).
There are no new regulatory commitments contained in this letter. Should you have any questions regarding this submittal, please contact Tim Grimme, Peach Bottom Regulatory Assurance, at 267-533-7218.
Respectfully, Martin A. Bonifanti Site Vice President Peach Bottom Atomic Power Station Enclosure cc:
Director, Office of Nuclear Reactor Regulation NRC Region I Administrator NRC Resident Inspector NRC Project Manager
CCN 26-001 Page 1 of 2 Peach Bottom Atomic Power Station 1848 Lay Road, Delta PA 17314 Enclosure Peach Bottom Atomic Power Station Part 21 Notification of Fairbanks Morse Defense Liner, Cylinder, Kit, F/Diesel Gen, MOD-38TD8-1/8
- i. Name and address of the individual or individuals informing the Commission.
Mr. Martin A. Bonifanti Site Vice President Peach Bottom Atomic Power Station 1848 Lay Road Delta, PA 17314 ii. Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect.
Peach Bottom Atomic Power Station Units 2 & 3 (Peach Bottom)
Subsequent Renewed Facility Operating License Nos. DPR-44, DPR-56 NRC Docket No. 50-277, 50-278 Basic Component: Fairbanks Morse Defense part number: Liner, Cylinder, Kit, F/Diesel Gen, MOD-38TD8-1/8.
iii. Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.
Fairbanks Morse Defense 701 White Avenue Beloit, WI 53511 iv. Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.
Per Constellation purchasing requirements, the cylinder liners are required to have single pass (one continuous layer) hard chrome plating. A cylinder liner chrome plating delamination caused an EDG functional failure.
Peach Bottom has concluded that this defect constitutes a Substantial Safety Hazard (SSH). A SSH exists because the nature of the defect was such that it would have prevented the fulfillment of a safety function.
- v. The date on which the information of such defect or failure to comply was obtained.
Peach Bottom determined a defect of the basic component that could cause a substantial safety hazard existed on December 15, 2025.
CCN 26-001 Page 2 of 2 Peach Bottom Atomic Power Station 1848 Lay Road, Delta PA 17314 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 number of impacted cylinder liner kits is unknown.
Peach Bottom has coordinated with Fairbanks Morse Defense to review parts manufactured under similar conditions of the failed cylinder liner. This review has concluded that a population of five parts that underwent chrome plating on October 25, 2013 may be potentially susceptible to a similar defect, serial numbers include: H837-1, H837-2, H838-1, H832-2, and H9311-2.
Serial number H837-1 is the failed cylinder liner in the Peach Bottom E1 EDG.
Serial numbers H838-1 and H832-2 are installed in the Peach Bottom E1 EDG.
Serial number H837-2 is currently installed in the D14 EDG at Limerick Generating Station.
Limerick Generating Station has been notified of the Peach Bottom cylinder liner failure, provided the Peach Bottom failure analysis and the conclusions of the engineering evaluation.
Serial number H9311-2 has not been located within Peach Bottom inventory.
Fairbanks Morse Defense has been requested to provide information related to this cylinder liner.
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.
Immediate action:
E1 EDG failed cylinder liner was replaced.
Future Action:
None.
viii. Any advice related to the 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.
None. Peach Bottom will continue to specify in purchasing requirements that the cylinder liners are required to have single pass (one continuous layer) hard chrome plating.
ix. In the case of an early site permit, the entities to whom an early site permit was transferred.
Not applicable.