ML25149A065
| ML25149A065 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 06/05/2025 |
| From: | V Sreenivas Plant Licensing Branch 1 |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| Kim, J | |
| References | |
| EPID L-2025-LRO-0011 | |
| Download: ML25149A065 (3) | |
Text
June 5, 2025 Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
R. E. GINNA NUCLEAR POWER PLANT - REVIEW OF SPRING 2023 STEAM GENERATOR TUBE INSPECTION REPORT FOR REFUELING OUTAGE G1R44 (EPID: L-2025-LRO-0011)
Dear Mr. Rhoades:
By letter dated October 18, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23291A081), Constellation Energy Generation LLC (the licensee) submitted information to the U.S. Nuclear Regulatory Commission (NRC) summarizing the results of the spring 2023 steam generator inspections performed at R. E. Ginna Nuclear Power Plant (Ginna). These inspections were performed during refueling outage G1R44.
The NRC staff has completed its review of the submittal and concludes that the licensee provided the information required by Ginnas technical specifications. No additional follow-up is required at this time. The results of the NRC staffs review and observations are enclosed.
If you have any questions, please contact me at 301-415-2597 or via email at V.Sreenivas@nrc.gov.
Sincerely,
/RA/
V. Sreenivas, Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-244
Enclosure:
Review of the Steam Generator Tube Inspection Report cc: Listserv
Enclosure REVIEW OF SPRING 2023 STEAM GENERATOR TUBE INSPECTION REPORT CONSTELLATION ENERGY GENERATION LLC R. E. GINNA NUCLEAR POWER PLANT DOCKET NO. 50-244 By letter dated October 18, 2023 (Agencywide Documents Access and Management System Accession No. ML23291A081), Constellation Energy Generation LLC (the licensee) submitted information to the U.S. Nuclear Regulatory Commission (NRC) summarizing the results of the spring 2023 steam generator (SG) inspections performed at R. E. Ginna Nuclear Power Plant (Ginna). These inspections were performed during refueling outage G1R44. The information was submitted in accordance with the Ginna Technical Specification (TS) 5.6.7, Steam Generator Tube Inspection Report, which requires that a report be submitted within 180 days after the initial entry into hot shutdown (MODE 4) following completion of an inspection of the SGs.
Ginna has two SGs designed and fabricated by Babcock and Wilcox International. Each SG contains 4,765 thermally treated Alloy 690 tubes. Each tube has a nominal outside diameter of 0.750 inches and a nominal wall thickness of 0.043 inches. The tubes were hydraulically expanded at both ends for the full length of the tubesheet and are supported by stainless steel lattice grid supports.
The licensee provided the scope, extent, methods, and results of its SG tube inspections in the letter referenced above. In addition, the licensee described corrective actions (e.g., tube plugging) taken in response to the inspection findings.
Based on its review of the report submitted, the NRC staff has the following observations:
During refueling outage G1R44, the licensee visually inspected the primary and secondary moisture separators and performed laser profilometry of all secondary moisture separator base plates and sidewalls. The licensee reported that flow accelerated corrosion, reported after the 2014 inspections, has continued and that portions of the secondary sidewall and primary separators have through-wall holes.
During refueling outage G1R44, material and schedule allowed for 40 base plate repairs (i.e., welded patch plates), which were prioritized based on degradation projections.
The licensee plans to perform steam drum moisture separator inspections, along with sludge lancing and top of tubesheet foreign object search and retrieval, prior to the next refueling outage when SG tube eddy current inspections will be performed.
Based on a review of the information provided, the NRC staff concludes that the licensee provided the information required by its TSs. In addition, the staff concludes there are no technical issues that warrant follow-up action at this time, since the inspections appear to be consistent with the objective of detecting potential tube degradation, and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
- by memorandum dated 4/25/2025 **by eConcurrence OFFICE NRR/DORL/LPL1/PM**
NRR/DORL/LPL1/LA**
NRR/DNRL/NCSG/BC*
NAME VSreenivas KEntz (PBlechman for)
SBloom DATE 5/23/2025 6/2/2025 4/25/2025 OFFICE NRR/DORL/LPL1/BC**
NRR/DORL/LPL1/PM**
NAME HGonzález (RGuzman for)
VSreenivas DATE 6/4/2025 6/5/2025