ML22263A025
| ML22263A025 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 09/15/2022 |
| From: | James Holloway Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 22-257 | |
| Download: ML22263A025 (4) | |
Text
V IRGINIA E LECTRIC AND P OWER C O MPANY RICHMOND, V IRGINIA 23261 September 15, 2022 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 10 CFR 50.90 Serial No.:
22-257 NRA/GDM:
RO Docket Nos.:
50-280/281 License Nos.: DPR-32/37 CORRECTION OF DOCUMENTATION ERROR IDENTIFIED IN LICENSE AMENDMENT REQUEST TO UPDATE ALTERNATIVE SOURCE TERM DOSE CONSEQUENCES ANALYSES By letter dated March 2, 2018 (Serial No.18-069) [ADAMS Accession No. ML18075A021], Virginia Electric and Power Company (Dominion Energy Virginia) requested amendments, in the form of changes to the Technical Specifications (TS) to Facility Operating License Numbers DPR-32 and DPR-37 for Surry Power Station (SPS) Units 1 and 2.
As part of the proposed changes, the License Amendment Request (LAR) updated the alternative source term (AST) dose consequences analyses. The Nuclear Regulatory Commission (NRC) approved the LAR in SPS TS Amendments 295 and 295 for SPS Units 1 and 2, respectively, dated June 12, 2019
[ADAMS Accession No. ML19028A384].
Subsequent to the submittal of the LAR and receipt of the associated license amendments, a documentation error was identified in one of the tables included in the LAR associated with the updated steam generator tube rupture (SGTR) analysis of record (AOR).
Specifically, the data provided in Table 3.4-7, Power Available -
Ruptured SG (RSG) Break Flow, supports the SGTR with power available case.
However, the flashed break flow rate data and a start time for the flow rate change included in Table 3.4-7 were subsequently determined to be incorrect. The error in Table 3.4-7 resulted from copying data tables from an earlier version of the SGTR calculation and not updating all the parameters. The incorrect values are highlighted in the table below Table 3.4-7 Power Available - Ruptured SG (RSG) Break Flow time Liquid Break Flow Flashed Break (RCS to SG liquid)
(hrs) lbm/min lbm/min 0
4970 689 0.0222 5285 114 0.0508 4518 60 0.5 0
0
The corrected Table 3.4-7 is provided below.
Serial No.22-257 Docket Nos. 50-280/281 Documentation Error Correction Page 2 of 4 Corrected Table 3.4*7 Power Available - Ruptured SG (RSG) Break Flow time Liquid Break Flow Flashed Break (RCS to SG liquid)
(hrs) lbm/min lbm/min 0
4970 712 0.0222 5285 107 0.0561 4518 73 0.5 0
0 Even though Table 3.4-7 included incorrect data, the updated AST dose consequences for the SGTR included in Section 3.4.6, SGTR Analysis Results, of the LAR were not affected by the documentation error because the correct parameters were used in the RADTRAD-NAI files that were used to run the power available cases.
In addition, as noted in the NRC safety evaluation report (SER) for SPS Amendments 295/295, "The NRG staff compared the doses estimated by the licensee [which were based on the correct data] to the accident dose criteria of 25 rem at the EAB and LPZ for the pre-accident iodine spike analysis and 2. 5 rem at the EAB and LPZ for the concurrent iodine spike analysis as stated in RG 1. 183 and SRP 15. 0. 1, and to the results estimated in the NRG staff independent calculations, which were performed to ensure a thorough understanding of the licensee's assumptions and methods.
Specifically, the NRG staff found that the inputs and assumptions used by the licensee are reasonable and that the licensee's dose estimates, which are comparable to those calculated by the NRG staff, are below the regulatory limits. The NRG staff finds that the licensee demonstrated that there is reasonable assurance that the estimates of the total effective dose equivalent due to a postulated design-basis SG TR comply with the accident dose criteria in RG 1. 183, SRP 15. 0. 1, and the radiation dose limits 10 GFR 50.67, which are 25 rem at the EAB and LPZ and 5 rem in the control room. Therefore, the staff finds the proposed SG TR analysis changes acceptable."
Therefore, the NRC SER conclusion regarding the acceptability of the SPS updated AST SGTR dose consequences analysis was based on: 1) reasonable inputs and assumptions that resulted in the dose consequences that Dominion Energy Virginia calculated being less than the regulatory limits, and 2) the comparable dose estimates independently calculated by the NRC to validate Dominion Energy Virginia's methods and assumptions. The corrected input for the ruptured SG flashed break flow for the power available case remains reasonable because the corrected input is not significantly different than the original values, as shown in the Tables above.
Consequently, the conclusions of the NRC SER are not affected.
Conclusion Serial No.22-257 Docket Nos. 50-280/281 Documentation Error Correction Page 3 of 4 Dominion Energy Virginia performed the updated AST dose consequences analysis for the SGTR event using the correct data; therefore, the analysis results presented in the March 2, 2018, LAR are unaffected by the documentation error and remain accurate, unchanged and within regulatory limits.
In addition, since the NRG performed an independent dose consequences calculation of the SGTR event with acceptable analysis results comparable to those calculated by Dominion Energy Virginia, it is concluded the NRG determination provided in their June 12, 2019, SER for SPS TS Amendments 295 and 295 for SPS Units 1 and 2, respectively, regarding the acceptability of the dose consequences analyses included in the LAR is likewise unaffected.
Should you have any questions or require additional information, please contact Mr. Gary D. Miller at (804) 273-2771.
Respectfully, James E. Holloway Vice President - Nuclear Engineering and Fleet Support Commitments contained in this letter: None COMMONWEAL TH OF VIRGINIA
)
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COUNTY OF HENRICO
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Kathryn Hill Barret Notary Public Commonwealth of Virginia Reg. No. 7905256 My Commission Expires January 31, 2024 The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. James E. Holloway, who is Vice President - Nuclear Engineering and Fleet Support, of Virginia Electric and Power Company.
He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.
5 th.
Acknowledged before me this \\
day of Seyicmbe <'
, 2022.
My Commission Expires: "3o.nuet-r'I 3111 02 4.
cc:
U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, GA 30303-1257 Mr. L. John Klos NRC Project Manager - Surry U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 09 E-3 11555 Rockville Pike Rockville, MD 20852-2738 Mr. G. Edward Miller NRC Senior Project Manager - North Anna U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 09 E-3 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Surry Power Station State Health Commissioner Virginia Department of Health James Madison Building - 7th floor 1 09 Governor Street Suite 730 Richmond, VA 23219 Serial No.22-257 Docket Nos. 50-280/281 Documentation Error Correction Page 4 of 4