L-2021-137, GL 2004-02 Debris Transport Calculation Non-Conservatism
| ML21204A052 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 07/23/2021 |
| From: | Deboer D Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL 2004-02, L-2021-137 | |
| Download: ML21204A052 (4) | |
Text
July 23, 2021 Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957 L-2021-137 GL 2004-02 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington DC 20555-0001 RE: St. Lucie Nuclear Plant, Units 1 and 2 Docket Nos. 50-335 and 50-389 Renewed Facility Operating Licenses DPR-67 and NPF-16 GL 2004-02 Debris Transport Calculation Non-Conservatism
References:
- 1.
Florida Power & Light Company letter L-2017-210, Updated Final Response to NRC Generic Letter 2004-02, December 20, 2017 (ADAMS Accession No. ML17362A108)
- 2.
Florida Power & Light Company letter L-2020-165, Supplement to Updated Final Response to NRC Generic Letter 2004-02, December 4, 2020 (ADAMS Accession No. ML20339A501)
In Reference 1, as supplemented by Reference 2, Florida Power & Light Company (FPL) provided an updated final response to Generic Letter (GL) 2004- 02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors, (ADAMS Accession No. ML042360586), for St. Lucie Units 1 and 2 (St. Lucie).
Recently, FPL learned of a non-conservatism in the St. Lucie debris transport evaluation that supported the submittal in Reference 1. Specifically, the non-conservatism occurred when determining the debris transport fractions for postulated reactor nozzle breaks, which incorrectly applied the pool fill-up transport fractions for selected debris types, resulting in non-conservative transported debris quantities. The issue has been entered into the St. Lucie corrective action program (CAP), and the calculations containing the non-conservatism have been revised. The revision increased the overall transport fractions for the fine debris from 97% to 100% for the reactor nozzle breaks. Table 3.e.6-14 and Table 3.e.6-17 of the enclosure to this letter provide the corrected debris transport fraction values for the reactor nozzle breaks for St. Lucie. These tables supersede Table 3.e.6-14 and Table 3.e.6-17 of Reference 1. The non-conservatism did not impact the limiting breaks scenarios evaluated in Reference 1, as shown in existing Table 3.e.6-19 through Table 3.e.6-21 of Reference 1. As a result, the conclusions specified in Reference 1 are not affected.
St. Lucie Nuclear Plant, Units 1 and 2 Docket Nos. 50-335 and 50-389 This letter contains no new regulatory commitments.
L-2021-137 Page 2 of 2 Should you have any questions regarding this submittal, please contact Mr. Wyatt Gades, St. Lucie Licensing Manager, at (772) 467-7435.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on 1~tr 23J.20'-i Sincerely, Daniel DeBoer Site Vice President St. Lucie Nuclear Plant DD/jam/res Enclosure cc:
USNRC Regional Administrator, Region II USNRC Project Manager, St. Lucie Nuclear Plant, Units 1 and 2 USNRC Senior Resident Inspector, St. Lucie Nuclear Plant, Units 1 and 2 Ms. Cindy Becker, Florida Department of Health
St. Lucie Nuclear Plant, Units 1 and 2 L-2021-137 Docket Nos. 50-335 and 50-389 Enclosure Page 1 of 2 Table 3.e.6-14 (Revised), PSL1 Overall Transport Fractions for a Reactor Cavity Break Debris Type Debris Size 1 Train 2 Train Generic Fiberglass Fines Small Pieces Transport as Erosion Fines Transport as Small Pieces Large Pieces Transport as Erosion Fines Transport as Large Pieces Intact Blankets Nukon Fines 100%
100%
Small Pieces Transport as Erosion Fines 9%
9%
Transport as Small Pieces 29%
47%
Large Pieces Transport as Erosion Fines 8%
8%
Transport as Large Pieces 4%
7%
Intact Blankets 0%
0%
Thermal-Wrap Fines 100%
100%
Small Pieces Transport as Erosion Fines 9%
9%
Transport as Small Pieces 29%
47%
Large Pieces Transport as Erosion Fines 8%
8%
Transport as Large Pieces 4%
7%
Intact Blankets 0%
0%
Temp-Mat Fines 100%
100%
Small Pieces Transport as Erosion Fines 9%
9%
Transport as Small Pieces 83%
83%
Large Pieces Transport as Erosion Fines 8%
8%
Transport as Large Pieces 73%
73%
Intact Blankets 0%
0%
Mirror RMI Fines 5%
13%
Large Pieces 6%
11%
Transco RMI Fines 5%
13%
Large Pieces 6%
11%
Transco RMI (inside cavity)
Fines 3%
7%
Large Pieces 0%
0%
Non-banded Cal-Sil Fines 100%
100%
Small Pieces Transport as Erosion Fines 17%
17%
Transport as Small Pieces 6%
14%
Banded Cal-Sil Fines 100%
100%
Small Pieces Transport as Erosion Fines 17%
17%
Transport as Small Pieces 6%
14%
Qualified Coatings Particulate 100%
100%
Unqualified Coatings Particulate 100%
100%
Latent Debris Particulate/Fiber 100%
100%
St. Lucie Nuclear Plant, Units 1 and 2 L-2021-137 Docket Nos. 50-335 and 50-389 Enclosure Page 2 of 2 Table 3.e.6-17 (Revised), PSL2 Overall Transport Fractions for a Reactor Cavity Break Debris Type Debris Size 1 Train 2 Train LDFG Fines Small Pieces Transport as Erosion Fines Transport as Small Pieces Large Pieces Transport as Erosion Fines Transport as Large Pieces Intact Blankets Nukon Fines 100%
100%
Small Pieces Transport as Erosion Fines 10%
9%
Transport as Small Pieces 10%
18%
Large Pieces Transport as Erosion Fines 8%
8%
Transport as Large Pieces 2%
5%
Intact Blankets 0%
0%
Nukon (inside cavity)
Fines 100%
100%
Small Pieces Transport as Erosion Fines 10%
10%
Transport as Small Pieces 5%
8%
Large Pieces Transport as Erosion Fines 10%
10%
Transport as Large Pieces 0%
0%
Intact Blankets 0%
0%
Mirror RMI Fines 1%
9%
Large Pieces 2%
5%
Mirror RMI (inside cavity)
Fines 1%
4%
Large Pieces 0%
0%
Transco RMI Fines Large Pieces Cal-Sil Fines 100%
100%
Small Pieces Transport as Erosion Fines 17%
17%
Transport as Small Pieces 1%
7%
Qualified Coatings Particulate 100%
100%
Unqualified Coatings Particulate 100%
100%
Latent Debris Particulate/Fiber 100%
100%