ML24100A069
| ML24100A069 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 04/09/2024 |
| From: | Hardy J Entergy Operations |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| GNRO2024-00013 | |
| Download: ML24100A069 (1) | |
Text
E) entergy GNRO2024-00013 April 9, 2024 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, D.C. 20555-0001 Entergy Operations, Inc.
P.O. Box 756 Port Gibson, Mississippi 39150 Jeffery Hardy Manager Regulatory Assurance Grand Gulf Nuclear Station Tel: 802-380-5124
SUBJECT:
Grand Gulf Nuclear Station Unit 1, Report of Changes or Errors to 10 CFR 50.46 Analysis
REFERENCE:
Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29
- 1. Entergy letter to NRC, GNRO2021-00037 "2021 Annual Report of Changes and Errors to 1 0 CFR 50.46 Analysis Grand Gulf Nuclear Station, Unit 1" dated November 30, 2021 (ADAMS Accession No. ML21334A286).
In accordance with 1 0 CFR 50.46(a)(3)(ii), Grand Gulf Nuclear Station, Unit 1 (GGNS), is required to report to the Nuclear Regulatory Commission, at least annually, the estimated effect on the limiting Emergency Core Cooling System (ECCS) analysis caused by changes to or errors discovered in the accepted ECCS evaluation model.
Since the last 1 0 CFR 50.46(a)(3)(ii) report, [Reference 1 ], there has been one insignificant error identified. The table below summarizes the effect of the recent notification (2023-02) to the GGNS ECCS analysis performed by General Electric-Hitachi Nuclear Energy (GEH) for the current reporting period.
The current Licensing Basis peak cladding temperature (PCT) results in a projected current PCT of approximately 1675°F. This is below the 2200°F acceptance criterion of 1 0 CFR 50.46.
GNRO2024-00013 Page 2 of 2 Notification Nature of Change or Error to 1 O CFR 50.46 Analysis 2023-02 TRACG Default Inputs for 3-stage steam separator are not consistent with actual 3-stage steam separator geometry used by GEH/GNF to demonstrate compliance with the Emergency Core Cooling System (ECCS) performance requirements of 1 0CFR50.46. Two default values for the axial distance between the exit of the first discharge passage and the swirl vane exit and the length of the separating barrel for the 3-stage steam separator were not consistent with actual 3-stage steam separator geometry.
TRACG-LOCA analyses which are limited by steam line breaks are expected to have a small PCT impact accumulate due to the prolonged, high flowrate through the separators. For these analyses, the steam separator inputs are updated in the TRACG-LOCA basedeck and a plant-specific PCT impact is calculated.
TRACG-LOCA analyses limited by breaks in other locations are estimated to have a 0 degrees Fahrenheit (F) impact due to the low flow through the steam separators and the relatively small error in the steam separator modeling.
Estimated PCT Effect (~PCT) 0°F There are no commitments contained in this submittal. If you have any questions or need additional information, please contact me at 802-380-5124.
Si~
~ 0 JH/ram cc:
NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001