NL-22-0510, Plants Units 1 and 2, 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021
| ML22195A060 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Vogtle, Farley  |
| Issue date: | 07/14/2022 |
| From: | Gayheart C Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-22-0510 | |
| Download: ML22195A060 (6) | |
Text
Regulatory Affairs 3535 Colonnade Parkway Birmingham, AL 35243 205.992.5316 tel July 14, 2022 Docket Nos.: 50-321 50-348 50-424 NL-22-0510 50-366 50-364 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant Units 1 and 2 Joseph M. Farley Nuclear Plant Units 1 and 2 Vogtle Electric Generating Plant Units 1 and 2 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021 Ladies and Gentlemen:
Southern Nuclear Operating Company (SNC) is the licensed operator for the Edwin I. Hatch Nuclear Plant (HNP) Units 1 and 2, the Joseph M. Farley Nuclear Plant (FNP) Units 1 and 2, and the Vogtle Electric Generating Plant (VEGP) Units 1 and 2. The requirements of 10 CFR 50.46(a)(3)(ii) include an annual report by licensees of changes to, or errors in, acceptable emergency core cooling system (ECCS) models that affect the temperature calculation and the estimated effect of changes or errors on the limiting ECCS analysis.
Accordingly, the reports required by 10 CFR 50.46(a)(3)(ii) for HNP Units 1 and 2 are provided in the enclosures to this letter.
For calendar year 2021, there were no changes or errors to report for FNP Units 1 and 2, and VEGP Units 1 and 2 ECCS models that affected the temperature calculation; thus, no reports are required for those units.
The resulting peak cladding temperatures (PCT) for HNP Units 1 and 2, FNP Units 1 and 2, and VEGP Units 1 and 2 continue to meet the criterion of 10 CFR 50.46(b)(1) (i.e., 2200°F).
This letter contains no NRC commitments. If you have any questions, please contact Amy Chamberlain at 205.992.6361.
Respectfully submitted, Cheryl A. Gayheart Regulatory Affairs Director CAG/tle
U. S. Nuclear Regulatory Commission NL-22-0510 Page 2
Enclosures:
- 1. Edwin I. Hatch Nuclear Plant Unit 1 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021
- 2. Edwin I. Hatch Nuclear Plant Unit 2 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021 cc: Regional Administrator, Region ll NRR Project Manager - HNP, FNP, VEGP 1 & 2 Senior Resident Inspector - HNP, FNP, VEGP 1 & 2 NRR Project Manager - HNP, FNP, VEGP 1 & 2 RType: CGA02.001
Edwin I. Hatch Nuclear Plant Units 1 and 2 Joseph M. Farley Nuclear Plant Units 1 and 2 Vogtle Electric Generating Plant Units 1 and 2 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021 Enclosure 1 Edwin I. Hatch Nuclear Plant Unit 1 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021
Enclosure to NL-22-0510 Edwin I. Hatch Nuclear Plant Unit 1 - 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021 Edwin I. Hatch Nuclear Plant Unit 1 Table 1 TRACG-LOCA Summary of Changes/Errors for Calendar Year 2021 (GNF2, GNF3)
Estimated Description Effect
( PCT, °F)
Discrepancy in Inner Cladding Surface Roughness (Reference 1-1). 0 Noncondensable Gas Error in Zero Cell Side Branch (Reference 1-2). 0 Incorrect Number of Core Support Plate Flow Holes for Vessel Leakage Path 0
(Reference 1-3).
Incorrect Upper Plenum Volume (Reference 1-4). 0 TRACG04P Version 4.2.76.1 (Reference 1-5) 0 Table 1 TRACG-LOCA Cumulative Impact of Changes/Errors GNF2 GNF3 Description lPCTl (°F) lPCTl (°F)
Changes/Errors Affecting PCT Previously Reported 35 35 (See Note)
Summary of Changes/Errors Affecting PCT for 0 0 Calendar Year 2021 (from Table 1-1)
Cumulative Total 35 35 Note: The TRACG radiation heat transfer calculation error (35°F) is applicable to TRACG-LOCA. It was previously reported for HNP Unit 1 in Reference 1-6.
References:
1-1. GE Hitachi 10 CFR 50.46 Notification Letter 2021-02, dated February 18, 2021 1-2. GE Hitachi 10 CFR 50.46 Notification Letter 2021-04, dated July 6, 2021 1-3. GE Hitachi 10 CFR 50.46 Notification Letter 2021-05, dated August 19, 2021 1-4. GE Hitachi 10 CFR 50.46 Notification Letter 2021-08, dated October 14, 2021 1-5. GE Hitachi 10 CFR 50.46 Notification Letter 2021-09, dated October 14, 2021 1-6. Letter from Cheryl A. Gayheart to USNRC (NL-21-0606), ML21182A369, Edwin I. Hatch Nuclear Plant Units 1 and 2, Joseph M. Farley Nuclear Plant Units 1 and 2, Vogtle Electric Generating Plant Units 1 and 2, 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2020, dated July 1, 2021 E1-1
Edwin I. Hatch Nuclear Plant Units 1 and 2 Joseph M. Farley Nuclear Plant Units 1 and 2 Vogtle Electric Generating Plant Units 1 and 2 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021 Enclosure 2 Edwin I. Hatch Nuclear Plant Unit 2 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021
Enclosure to NL-22-0510 Edwin I. Hatch Nuclear Plant Unit 2 - 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2021 Edwin I. Hatch Nuclear Plant Unit 2 Table 2 TRACG-LOCA Summary of Changes/Errors for Calendar Year 2021 (GNF2, GNF3, GNF3 LUAs)
Estimated Description Effect
( PCT, °F)
Discrepancy in Inner Cladding Surface Roughness (Reference 2-1). 0 Noncondensable Gas Error in Zero Cell Side Branch (Reference 2-2). 0 Incorrect Number of Core Support Plate Flow Holes for Vessel Leakage Path 0
(Reference 2-3).
Incorrect Upper Plenum Volume (Reference 2-4). 0 TRACG04P Version 4.2.76.1 (Reference 2-5) 0 Table 2 TRACG-LOCA Cumulative Impact of Changes/Errors GNF2 GNF3 GNF3 LUAs Description lPCTl (°F) lPCTl (°F) lPCTl (°F)
Changes/Errors Affecting PCT Previously 35 35 35 Reported (See Note)
Summary of Changes/Errors Affecting PCT for 0 0 0 Calendar Year 2021 (from Table 2-1)
Cumulative Total 35 35 35 Note: The TRACG radiation heat transfer calculation error (35°F) is applicable to TRACG-LOCA. It was previously reported for HNP Unit 2 in Reference 2-6.
References:
2-1. GE Hitachi 10 CFR 50.46 Notification Letter 2021-02, dated February 18, 2021 2-2. GE Hitachi 10 CFR 50.46 Notification Letter 2021-04, dated July 6, 2021 2-3. GE Hitachi 10 CFR 50.46 Notification Letter 2021-05, dated August 19, 2021 2-4. GE Hitachi 10 CFR 50.46 Notification Letter 2021-08, dated October 14, 2021 2-5. GE Hitachi 10 CFR 50.46 Notification Letter 2021-09, dated October 14, 2021 2-6. Letter from Cheryl A. Gayheart to USNRC (NL-20-0630), ML20176A577, Edwin I. Hatch Nuclear Plant Units 1 and 2, Joseph M. Farley Nuclear Plant Units 1 and 2, Vogtle Electric Generating Plant Units 1 and 2, 10 CFR 50.46 ECCS Evaluation Model Annual Report for 2019, dated June 19, 2020 E2-1