ML051860397

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Annual Report of Emergency Core Cooling System Model Changes
ML051860397
Person / Time
Site: Millstone, Surry, North Anna  Dominion icon.png
Issue date: 06/30/2005
From: Grecheck E
Dominion, Dominion Nuclear Connecticut, Dominion Resources Services, Virginia Electric & Power Co (VEPCO)
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
05-380
Download: ML051860397 (27)
v • d • e


Text

iPDominion June 30, 2005 U.S. Nuclear Regulatory Commission Serial No.05-380 Attention: Document Control Desk NL&OS/PRW RO Washington, DC 20555 Docket Nos. 50-336/423 50-338/339 50-280/281 License Nos. DPR-65/NPF-49 NPF-4/7 DPR-32/37 DOMINION NUCLEAR CONNECTICUT, INC.

VIRGINIA ELECTRIC AND POWER COMPANY MILLSTONE POWER STATION UNITS 2 AND 3 NORTH ANNA POWER STATION UNITS 1 AND 2 SURRY POWER STATION UNITS 1 AND 2 2004 ANNUAL REPORT OF EMERGENCY CORE COOLING SYSTEM MODEL CHANGES PURSUANT TO THE REQUIREMENTS OF 10 CFR 50.46 In accordance with 10 CFR 50.46(a)(3)(ii), Dominion Nuclear Connecticut, Inc. and Virginia Electric and Power Company (Dominion) hereby submit the annual summary of changes to and errors identified in the Emergency Core Cooling System (ECCS) Evaluation Models or applications of those models for the following stations/units:

Millstone Power Station Units 2 and 3 North Anna Power Station Units 1 and 2 Surry Power Station Units 1 and 2. provides a report describing plant-specific evaluation model changes associated with the Westinghouse and AREVA Small Break Loss of Coolant Accident (SBLOCA) and Large Break Loss of Coolant Accident (LBLOCA) ECCS Evaluation Models for Millstone Power Station (MPS), North Anna Power Station (NAPS), and Surry Power Station (SPS). NAPS Units 1 and 2 have both Westinghouse and AREVA fuel, therefore, both evaluation model results are provided for NAPS.

Information regarding the effect of the ECCS Evaluation Model changes upon the reported SBLOCA and LBLOCA analyses of record (AOR) results is provided for MPS, NAPS and SPS in Attachments 2, 3, and 4, respectively. To summarize the information in Attachments 2, 3, and 4, the calculated peak cladding temperature (PCT) for the SBLOCA and LBLOCA analyses for MPS, NAPS, and SPS are given below.

Serial Number 05-380 Docket Nos. 50-336/423/338/339/280/281 Annual Reporting of ECCS Model Changes Page 2 of 4 Millstone Unit 2 - Small break - AREVA Evaluation Model : 1808°F Millstone Unit 2 - Large break - AREVA Evaluation Model : 1823°F Millstone Unit 3 - Small break - Westinghouse Evaluation Model : 1009°F Millstone Unit 3 Large break - Westinghouse Evaluation Model : 2004°F North Anna Unit 1 - Small break - Westinghouse Evaluation Model : 1724°F North Anna Unit 1 - Large break - Westinghouse Evaluation Model : 2086°F North Anna Unit 1 - Small break - AREVA Evaluation Model : 1380°F North Anna Unit 1 - Large break - AREVA Evaluation Model : 1925°F North Anna Unit 2 - Small break - Westinghouse Evaluation Model : 1724°F North Anna Unit 2 - Large break - Westinghouse Evaluation Model : 2086°F North Anna Unit 2 - Small break - AREVA Evaluation Model : 1370°F North Anna Unit 2 - Large break - AREVA Evaluation Model : 1861"F Surry Units 1 and 2 - Small break - Westinghouse Evaluation Model : 1750°F Surry Units 1 and 2 - Large break - Westinghouse Evaluation Model : 2133°F The LOCA results for MPS 2 and 3, NAPS 1 and 2 and SPS 1 and 2 are confirmed to have sufficient margin to the 2200°F limit of 10 CFR 50.46. Based upon Dominion's evaluation of this information and the associated changes in the applicable licensing basis PCT results, no further action is required to demonstrate compliance with the 10 CFR 50.46 requirements. Reporting of this information is required per 10 CFR 50.46(a)(3)(ii), which obligates each licensee to report the effect upon calculated temperature of any change or error in evaluation models or their application on an annual basis.

This information satisfies the 2004 annual reporting requirements of 10 CFR 50.46(a)(3)(ii). In addition, no reanalysis or other actions are necessary to demonstrate compliance with 10 CFR 50.46 requirements.

If you have any further questions regarding this submittal, please contact Mr. Paul R.

Willoughby at (804) 273-3572.

Very truly yours, Eugene S. Grecheck Vice President - Nuclear Support Services Dominion Nuclear Connecticut, Inc.

Virginia Electric and Power Company

Serial Number 05-380 Docket Nos. 50-336/423/338/339/280/281 Annual Reporting of ECCS Model Changes Page 3 of 4 Commitments made in this letter:

1. None.

Attachments: (4)

1) Report of Changes in Westinghouse and AREVA ECCS Evaluation Models.
2) 2004 Annual Reporting of 10 CFR 50.46 Margin Utilization - Millstone Power Station Units 2 and 3.
3) 2004 Annual Reporting of 10 CFR 50.46 Margin Utilization - North Anna Power Station Units 1 and 2.
4) 2004 Annual Reporting of 10 CFR 50.46 Margin Utilization - Surry Power Station Units 1 and 2.

Serial Number 05-380 Docket Nos. 50-336/423/338/339/280/281 Annual Reporting of ECCS Model Changes Page 4 of 4 cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, Pennsylvania 19406-141 5 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23 T85 Atlanta, Georgia 30303-8931 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station Mr. J. T. Reece NRC Senior Resident Inspector North Anna Power Station Mr. N. P. Garrett NRC Senior Resident Inspector Surry Power Station Mr. V. Nerses NRC Senior Project Manager Millstone Power Station Unit 2 Mr. G. Wunder NRC Project Manager Millstone Power Station Unit 3 Mr. J. Honcharik NRC Project Manager North Anna Power Station, Mr. S. R. Monarque NRC Project Manager Surry Power Station

Serial Number 05-380 Docket Nos. 50-336/423/338/339/280/281 ATTACHMENT 1 REPORT OF CHANGES IN WESTINGHOUSE AND AREVA ECCS EVALUATION MODELS MILLSTONE POWER STATION UNITS 2 AND 3 NORTH ANNA POWER STATION UNITS 1 AND 2 SURRY POWER STATION UNITS 1 AND 2 DOMINION NUCLEAR CONNECTICUT, INC.

VIRGINIA ELECTRIC AND POWER COMPANY

Serial Number 05-380 Docket N0s. 50-336/423/338/339/280/281 Attachment 1, Page 1 of 3 Millstone Power Station Units 2 and 3 (MPS 2 & 3)

1. AREVA identified two errors in the MPS2 LBLOCA analysis. AREVA identified a loss coefficient mismatch between the RELAP4 and RFPAC/REFLEX computer codes in that not all of the downcomer, lower plenum and lower head loss coefficients in RELAP4 were included in the RFPAC/REFLEX code input. An evaluation with the loss coefficient correction resulted in a peak cladding temperature (PCT) impact of 0°F. AREVA identified an error in an adjustment made to the Reactor Coolant Pumps that is used to balance the system pressure drop in the steady-state initialization of the RELAP4 code. Correction of this error resulted in a PCT impact of -3°F. No errors or changes were identified in the SBLOCA analysis for MPS2.
2. In 2001, Westinghouse reanalyzed the MPS3 SBLOCA analysis using NOTRUMP with the COSl condensation model. The PCT for this reanalysis was 1009°F. Subsequently, the NRC approved the use of the COSl condensation model methodology in a letter (TAC No. MB8387) dated March 9, 2004.

Consequently, the MPS3 Final Safety Analysis Report (FSAR) was updated to reflect the reanalysis as the analysis of record (AOR). Westinghouse identified inconsistencies in several drift flux models as well as the nodal bubble rise/droplet fall models. Westinghouse, using plant specific calculations with the NOTRUMP code, demonstrated that correction of these inconsistencies resulted in 0°F impact on PCT.

Westing house identified the following errors and changes in the LBLOCA ECCS Evaluation model applicable to MPS3. Each was evaluated to have a PCT impact of 0°F. Since these items have no impact on PCT, they will not be shown on the PCT Margin Utilization sheets provided in Attachment 2.

a. LOCBART Fluid Property Logic
b. Steam Generator Inlet/Outlet Plenum Flow Areas
c. LBLOCA Initial Containment Relative Humidity Assumption
d. General Code Maintenance (BASH/NOTRUMP)

North Anna Power Station Units 1 and 2 (NAPS 1 & 2) and Surrv Power Station Units 1 and 2 (SPS 1 & 2)

1. Westinghouse identified the following changes and errors in the ECCS evaluation models for NAPS and SPS.
a. LOCBART Fluid Property Logic
b. Spacer Grid Heat Transfer Model Inputs
c. Reactor Coolant Pump Reference Conditions
d. Steam Generator Inlet/Outlet Plenum Flow Areas
e. LBLOCA Initial Containment Relative Humidity Assumption

Serial Number 05-380 Docket Nos. 50-336/423/338/339/280/281 Annual Reporting of ECCS Model Changes Attachment 1 Page 2 of 3 The LOCBART Fluid Property Logic error (item a.) was evaluated to determine the PCT impact on the Westinghouse LBLOCA evaluation model results applicable to NAPS 1 & 2 and SPS 1 & 2. The results of that evaluation are summarized as follows:

Site APCT, OF NAPS 1 and 2 0 SPS 1 and 2 +10 Westinghouse identified a discrepancy in the Spacer Grid Heat Transfer Model Inputs (item b.) for a plant with 15x15 fuel whereby the spacer grid blocked area ratio and open area fraction inputs were revised but not evaluated for impact on the LBLOCA analysis. NAPS 1 and 2 have 17x17 fuel and are therefore unaffected by this issue. SPS 1 and 2 have 15x15 fuel, but Westinghouse confirmed that these inputs remain unchanged from the values provided by Westinghouse Columbia in 1993. Westinghouse stated that if these values were used in the current LBLOCA AOR then SPS 1 and 2 are unaffected by this issue.

Since the input values, provided by Westinghouse Columbia, are used as inputs to the SPS LBLOCA analysis, SPS 1 and 2 are unaffected by this issue.

Various discrepancies were identified in the reference conditions used with the reactor coolant pump homologous curves (item c.). Westinghouse evaluated the identified discrepancies as having a negligible (APCT=O°F) effect on SBLOCA and LBLOCA analysis results.

Westinghouse redefined the basis for calculating the Steam Generator Inlet/Outlet Plenum Flow Areas (item d.) used with the SATAN-VI momentum flux model as the average area over the steam generator plenum height. This change resolves a discrepancy in the original calculation and provides a more appropriate basis for the corresponding flow area terms. Calculations using the SATAN-VI code indicated that this change has a negligible (APCT=O°F) effect on LBLOCA analysis results.

LBLOCA analyses have historically used maximum initial relative humidity (item e.) to specify the initial containment air and steam partial pressures. This assumption is conservative for a given total initial containment pressure, but is non-conservative for a given initial containment air partial pressure.

Westinghouse revised the historical assumption to reflect this distinction and analysis input guidelines were updated accordingly. For NAPS and SPS, the initial containment air partial pressures are specified consistent with Section 3.8 of the SPS Technical Specifications and Section 3.6.4 of the NAPS Technical Specifications. The initial containment steam partial pressures were conservatively chosen to minimize total containment pressure and to roughly

Serial Number 05-380 Docket Nos. 50-336/423/338/339/280/281 Annual Reporting of ECCS Model Changes Attachment 1 Page 3 of 3 approximate containment ventilation design conditions. The resulting initial containment relative humidities were significantly below the maximum relative humidity of 100%. In an evaluation for the plants within Westinghouse Pittsburgh LBLOCA cognizance, Westinghouse concluded that no PCT assessments are required, leading to an estimated PCT impact of 0°F. Since the NAPS and SPS LBLOCA analyses do not specify maximum relative humidity, but a conservatively low containment initial steam partial pressure, the LBLOCA analyses are unaffected by this issue.

Westinghouse determined that the nature of changes associated with General Code Maintenance (BASH/NOTRUMP) (item f.) resulted in an estimated PCT impact of 0°F.

Due to the nature of the LOCBART Fluid Property Logic issue (item a.) this item will be shown on the NAPS and SPS PCT Margin Utilization sheets contained as Attachments 3 and 4. Items b. through f. will not be shown since these items do not impact PCT.

2. No changes were made to or errors discovered in the AREVA (formerly Framatome ANP) NRC-approved SBLOCA or LBLOCA ECCS evaluation model or in the SBLOCA or LBLOCA applications thereof as related to NAPS Units 1 and 2.
3. A change was made to the NAPS1 High Head Safety Injection (HHSI) flow delivery curves. The change was prompted by a slightly weaker performance of the 1-CH-P-1B HHSl pump. The minimum required HHSl flows were changed slightly to envelop the 1-CH-P-1B actual pump performance. As a result of this change, above an RCS pressure of approximately 650 psia, the HHSl flows were no longer bounding for the limiting SBLOCA analysis (5.2 inch safety injection line break) using the AREVA SBLOCA ECCS evaluation model. Note that the NAPS1 HHSl flows provided a slight benefit below 650 psia. AREVA reanalyzed the limiting SBLOCA PCT case for NAPS1 (5.2 inch safety injection line break, mixed core case with PCT of 1404°F) using the revised HHSl flows. The PCT for the revised case was 1380°F resulting in a APCT = -24°F relative to the current AOR PCT of 1404°F. The AREVA LBLOCA analysis is unaffected by this issue since the revised HHSl flowrates are slightly higher below an RCS pressure of approximately 650 psia. The LBLOCA analysis reaches this pressure very early in the transient and the impact of the revised HHSl flow is negligible.

Serial Number 05-380 Docket Nos. 50-336/423 ATTACHMENT 2 2004 ANNUAL REPORTING OF 10 CFR 50.46 MARGIN UTILIZATION MILLSTONE POWER STATION UNITS 2 AND 3 DOMINION NUCLEAR CONNECTICUT, INC.

Serial Number 05-380 Docket Nos. 50-336/423 Attachment 2, Page 1 of 4 10 CFR 50.46 Margin Utilization - Small Break LOCA Plant Name: Millstone Power Station, Unit 2 Utility Name: Dominion Nuclear Connecticut, Inc.

Analvsis Information EM: PWR Small Break LOCA, Limiting Break Size: 0.08 ft' S-RELAP5 Based Analysis Date: 01/02 Vendor: AREVA Peak Linear Power: 15.1 kW/ft Notes: None Clad TemP (OF) -

Notes LICENSING BASIS Analysis of Record PCT 1941 (1)

MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. Decay Heat Model Error -133
2. Revised SBLOCA Guideline 0 (2)

B. Planned Plant Change Evaluations

1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None 0 (3)

D. Temporary ECCS Model Issues

1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1808 NOTES:

(1) New Analysis of Record using S-RELAP5 based methodology.

(2) Assessment of this change resulted in a APCT = +66"F. FRA-ANP provided this assessment for information. The +66"F assessment does not apply since the current Analysis of Record incorporates the revised SBLOCA guideline.

(3) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-3361423 Attachment 2, Page 2 of 4 10 CFR 50.46 Margin Utilization Large Break LOCA Plant Name: Millstone Power Station, Unit 2 Utility Name: Dominion Nuclear Connecticut, Inc.

Analvsis Information EM: SEM/PWR-98 Limiting Break Size: 1.O DECLG Analysis Date: 11/98 Vendor: AREVA Peak Linear Power: 15.1 kW/ft Notes: None Clad TemD c"m LICENSING BASIS Analysis of Record PCT 1814 MARGINALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. Corrected Corrosion Enhancement Factor -1
2. ICECON Coding Errors 0
3. Setting RFPAC Fuel Temperatures at Start of Reflood -2
4. SISPNCHhjun98 Code Error 0
5. Error in Flow Blockage Model in TOODEE2 0
6. Change in TOODEE2-Calculation of QMAX 0
7. Change in Gadolinia Modeling 0
8. PWR LBLOCA Split Break Modeling 0
9. TEOBY Calculation Error 0
10. Inappropriate Heat Transfer in TOODEE2 0
11. End-of-Bypass Prediction by TEOBY 0
12. R4SS Overwrite of Junction Inertia 0
13. Incorrect Junction Inertia Multipliers 1
14. Errors Discovered During RODEX2 V&V 0
15. Error in Broken Loop SG Tube Exit Junction Inertia 0
16. RFPAC Refill and Reflood Calculation Code Errors 16
17. Incorrect Pump Junction Area Used in RELAP4 0
18. Error in TOODEE2 Clad Thermal Expansion -1
19. Accumulator Line Loss Error -1 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. Inconsistent Loss Coefficients Used for Robinson LBLOCA 0
2. Pump Head Adjustment for Pressure Balance Initialization -3 D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1823 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-336/423 Attachment 2, Page 3 of 4 10 CFR 50.46 Margin Utilization Small Break LOCA Plant Name: Millstone Power Station, Unit 3 Utility Name: Dominion Nuclear Connecticut, Inc.

Analvsis Information EM: NOTRUMP Limiting Break Size: 3 Inches Analysis Date: 04/04 Vendor: W estinghouse FQ: 2.6 FAH: 1.7 Fuel: RFANantage 5H SGTP (%): 10 Notes: None Clad TemD ( O F ) Notes LICENSING BASIS Analysis of Record PCT 1009 (11 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. None 0 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. NOTRUMP Bubble Rise / Drift Flux Model Inconsistency Corrections D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1009 Notes:

(1) The SBLOCA was reanalyzed in 2001 using NOTRUMP with the COSl condensation model. The reanalysis did not become the Analysis of Record (AOR) until 2004.

(2) This error was identified by Westinghouse in 2003. It is applied to the 2004 Permanent ECCS Model Assessments consistent with the AOR date.

(3) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-336/423 Attachment 2, Page 4 of 4 10 CFR 50.46 Margin Utilization - Large Break LOCA Plant Name: Millstone Power Station, Unit 3 Utility Name: Dominion Nuclear Connecticut, Inc.

Analvsis Information EM: BASH Limiting Break Size: Cd=0.6 Analysis Date: 08/90 Vendor: Westinghouse FQ: 2.6 FAH: 1.7 Fuel: Vantage 5H SGTP (%): 10 Notes: VH5/RFA Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 1974 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. None 0 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None 0 (11 D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. Rebaseline of AOR LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2004 Notes :

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-338/339 ATTACHMENT 3 2004 ANNUAL REPORTING OF 10 CFR 50.46 MARGIN UTILIZATION NORTH ANNA POWER STATION UNITS 1 AND 2 VIRGINIA ELECTRIC AND POWER COMPANY

Serial Number 05-380 Docket Nos. 50-338/339 Attachment 3, Page 1 of 8 10 CFR 50.46 Margin Utilization - Westinghouse Small Break LOCA Plant Name: North Anna Power Station, Unit 1 Utility Name: Virginia Electric and Power Company Analvsis Information EM: NOTRUMP Limiting Break Size: 3 Inches Analysis Date: 1995 Vendor: W estinghouse FQ: 2.32 FAH: 1.65 Fuel: NAIF SGTP (%): 7 Notes: None Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 1704 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. NOTRUMP Specific Enthalpy Error 20
2. SALIBRARY Double Precision Error -15
3. Fuel Rod Initialization Error 10
4. Loop Seal Elevation Error -44
5. NOTRUMP-Mixture Level Tracking Errors 13 (11
6. Removal of Part Length CRDMs 1 (11
7. NOTRUMP-Bubble Rise/Drift Flux Model Inconsistencies 35 (1)

B. Planned Plant Change Evaluations

1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1724 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 2 of 8 10 CFR 50.46 Margin Utilization - Westinghouse Large Break LOCA Plant Name: North Anna Power Station, Unit 1 Utility Name: Virginia Electric and Power Company Analvsis Information EM: BASH Limiting Break Size: Cd=0.4 Analysis Date: 2004 Vendor: Westinghouse FQ: 2.1 9 FAH: 1.55 Fuel: NAIF SGTP (%): 7 Notes: None Clad Temp (OF) Notes LICENSING BASIS Analysis of Record PCT 2086 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. None 0 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. LOCBART Fluid Property Logic Issue 0 11)

D. Temporary ECCS Model Issues

1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2086 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 3 of 8 10 CFR 50.46 Margin Utilization - AREVA Small Break LOCA Plant Name: North Anna Power Station, Unit 1 Utility Name: Virginia Electric and Power Company Analvsis Information EM: AREVA SB EM Limiting Break Size: 5.2 Inches (SI Line)

Analysis Date: 2004 Vendor: AREVA FQ: 2.32 FAH: 1.65 Fuel: Advanced Mark-BW SGTP (%): 7 Notes: None Clad Tern0 (OF) Notes LICENSING BASIS Analysis of Record PCT 1404 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. None 0 B. Planned Plant Change Evaluations
1. Revised Test Flow Curve for HHSI C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1380 Notes:

{I} The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 4 of 8 10 CFR 50.46 Margin Utilization - AREVA Large Break LOCA Plant Name: North Anna Power Station, Unit 1 Utility Name: Virginia Electric and Power Company Analvsis Information EM: AREVA RLBLOCA EM Limiting - Break Size: DEGB Analysis Date: 2004 Vendor : AREVA FQ: 2.32 FAH: 1.65 Fuel: Mixed SGTP (%): 12 NAIF/Advanced Mark-BW Notes: None Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 1853 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. Forslund-Rohsenow Correlation Modeling 64
2. RWST Temperature Assumption 8
3. LBLOCNSeismic SG Tube Collapse 0 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None 0 D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1925 Notes:

(1) A generic steam generator LOCNseismic load evaluation was performed by Westinghouse to quantify the potential steam generator tube collapse, which may occur at the time of the LOCA due to combined LOCA and seismic loads. Based on this analysis, a total steam generator tube reduction equivalent to 5% tube plugging was allocated as a permanent assessment for those plants that do not have a detailed analysis. The 5% steam generator tube plugging reduction will be used to account for the effects of a combined LOCNseismic event at North Anna Unit 1 with the AREVA evaluation model.

(2) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 5 of 8 10 CFR 50.46 Margin Utilization - Westinghouse Small Break LOCA Plant Name: North Anna Power Station, Unit 2 Utility Name: Virginia Electric and Power Company Analvsis Information EM: NOTRUMP Limiting Break Size: 3 Inches Analysis Date: 1995 Vendor: Westinghouse FQ: 2.32 FAH: 1.65 Fuel: NAIF SGTP (%): 7 Notes: None Clad Temp (OF) Notes LICENSING BASIS Analysis of Record PCT 1704 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. NOTRUMP Specific Enthalpy Error 20
2. SALIBRARY Double Precision Error -15
3. Fuel Rod Initialization Error 10
4. Loop Seal Elevation Error -44
5. Removal of Part Length CRDMs 1 (1)
6. NOTRUMP-Mixture Level Tracking Errors 13 (11
7. NOTRUMP-Bubble Rise/Drift Flux Model Inconsistencies 35 (11 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1724 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 6 of 8 10 CFR 50.46 Margin Utilization - Westinghouse Large Break LOCA Plant Name: North Anna Power Station, Unit 2 Utility Name: Virginia Electric and Power Company Analvsis Information EM: BASH Limiting Break Size: Cd=0.4 Analysis Date: 2004 Vendor: Westinghouse FQ: 2.1 9 FAH: 1.55 Fuel: NAIF SGTP (%): 7 Notes: None Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 2086 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. None 0 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2086 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 7 of 8 10 CFR 50.46 Margin Utilization AREVA Small Break LOCA Plant Name: North Anna Power Station, Unit 2 Utilitv Name: Virainia Electric and Power ComDanv Analvsis Information EM: AREVA SB EM Limiting Break Size: 3 Inches Analysis Date: 2004 Vendor: AREVA FQ: 2.32 FAH: 1.65 Fuel: Advanced Mark-BW SGTP (%): 7 Notes: None Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 1370 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. None 0 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1370 (1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket No. 50-338/339 Attachment 3, Page 8 of 8 10 CFR 50.46 Margin Utilization - AREVA Large Break LOCA Plant Name: North Anna Power Station, Unit 2 Utility Name: Virginia Electric and Power Company Analvsis Information EM: AREVA RLBLOCA EM Limiting Break Size: DEGB Analysis Date: 2004 Vendor: AREVA FQ: 2.32 FAH: 1.65 Fuel: Mixed: SGTP (%): 12 NAIF/Advanced Mark-BW Notes: None Clad TemD ( O F ) Notes LICENSING BASIS Analysis of Record PCT 1789 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. Forslund-Rohsenow Correlation Modeling 64
2. RWST Temperature Assumption 8
3. LBLOCNSeismic SG Tube Collapse 0 (1)

B. Planned Plant Change Evaluations

1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1861 Notes:

(1)

. . A generic steam generator LOCNseismic load evaluation was performed by Westinghouse toquantify the potential steam generator tube collapse, which may occur at the time of the LOCA due to combined LOCA and seismic loads. Based on this analysis, a total steam generator tube reduction equivalent to 5% tube plugging was allocated as a permanent assessment for those plants that do not have a detailed analysis. The 5% steam generator tube plugging reduction will be used to account for the effects of a combined LOCNseismic event at North Anna Unit 2 with the AREVA evaluation model.

(2) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-280/281 ATTACHMENT 4 2004 ANNUAL REPORTING OF 10 CFR 50.46 MARGIN UTILIZATION SURRY POWER STATION UNITS 1 AND 2 VIRGINIA ELECTRIC AND POWER COMPANY

Serial Number 05-380 Docket Nos. 50-2801281 Attachment 4, Page 1 of 4 10 CFR 50.46 Margin Utilization Westinghouse Small Break LOCA Plant Name: Surry Power Station, Unit 1 Utility Name: Virginia Electric and Power Company Analvsis Information EM: NOTRUMP Limiting Break Size: 3 Inches Analysis Date: 1996 Vendor: Westinghouse FQ: 2.5 FAH: 1.7 Fuel: SIF SGTP (Yo): 15 Notes: None Clad Temp (OF) Notes LICENSING BASIS Analysis of Record PCT 1717 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. NOTRUMP - Mixture Level Tracking Errors 13
2. Removal of Part Length CRDMs -15
3. NOTRUMP-Bubble Rise/Drift Flux Model Inconsistencies 35 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1750 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-280/281 Attachment 4, Page 2 of 4 10 CFR 50.46 Margin Utilization - Westinghouse Large Break LOCA Plant Name: Surry Power Station, Unit 1 Utility Name: Virginia Electric and Power ComDanv Analvsis Information EM: BASH Limiting Break Size: Cd=0.4 Analysis Date: 2001 Vendor: Westinghouse FQ: 2.32 FAH: 1.62 Fuel: SIF SGTP (%): 15 Notes: None Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 21 17 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. LBLOCNSeismic SG Tube Collapse 0 {V
2. BASH EM Transient Termination 0
3. LOCBART ZIRLOTM Cladding Specific Heat Model Error 40
4. PAD 4.0 Initial Pellet Temperatures -40
5. Removal of Part-Length CRDMs 6 (21 B. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. LOCBART Fluid Property Logic Issue D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2133 Notes:

(1) A generic steam generator LOCNseismic load evaluation was performed by Westinghouse to quantify the potential steam generator tube collapse, which may occur at the time of the LOCA due to combined LOCA and seismic loads. Based on this analysis, a total steam generator tube reduction equivalent to 5% tube plugging was allocated as a permanent assessment for those plants that do not have a detailed analysis. The 5% steam generator tube plugging reduction will be used to account for the effects of a combined LOCNseismic event at Surry.

{2} The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-280/281 Attachment 4, Page 3 of 4 10 CFR 50.46 Margin Utilization - Westinghouse Small Break LOCA Plant Name: Surry Power Station, Unit 2 Utility Name: Virginia Electric and Power Company Analvsis Information EM: NOTRUMP Limiting Break Size: 3 Inches Analysis Date: 1996 Vendor: Westinghouse FQ: 2.5 FAH: 1.7 Fuel: SIF SGTP (%): 15 Notes: None Clad TemD (OF) Notes LICENSING BASIS Analysis of Record PCT 1717 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. NOTRUMP - Mixture Level Tracking Errors 13
2. Removal of Part Length CRDMs .15
3. NOTRUMP-Bubble Rise/Drift Flux Model Inconsistencies 35
8. Planned Plant Change Evaluations
1. None 0 C. 2004 Permanent ECCS Model Assessments
1. None D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 1750 Notes:

(1) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i).

Serial Number 05-380 Docket Nos. 50-280/281 Attachment 4, Page 4 of 4 10 CFR 50.46 Margin Utilization - Westinghouse Large Break LOCA Plant Name: Surry Power Station, Unit 2 Utility Name: Virginia Electric and Power Company Analvsis Information EM: BASH Limiting Break Size: Cd=0.4 Analysis Date: 2001 Vendor: Westinghouse FQ: 2.32 FAH: 1.62 Fuel: SIF SGTP (%): 15 Notes: None Clad Temp (OF) Notes LICENSING BASIS Analysis of Record PCT 21 17 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. LBLOCNSeismic SG Tube Collapse 0 (1)
2. BASH EM Transient Termination 0
3. LOCBART ZIRLOTM Cladding Specific Heat Model Error 40
4. PAD 4.0 Initial Pellet Temperatures -40
5. Removal of Part-Length CRDMs 6 (2)

B. Planned Plant Change Evaluations

1. None 0 C. 2004 Permanent ECCS Model Assessments
1. LOCBART Fluid Property Logic Issue 10 (21 D. Temporary ECCS Model Issues
1. None 0 E. Other Margin Allocations
1. None 0 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2133 Notes:

(1) A generic steam generator LOCNseismic load evaluation was performed by Westinghouse to quantify the potential steam generator tube collapse, which may occur at the time of the LOCA due to combined LOCA and seismic loads. Based on this analysis, a total steam generator tube reduction equivalent to 5% tube plugging was allocated as a permanent assessment for those plants that do not have a detailed analysis. The 5% steam generator tube plugging reduction will be used to account for the effects of a combined LOCNseismic event at Surry.

(2) The accumulation of changes for these items (sum of absolute magnitudes) since the last 30-day report or reanalysis is less than or equal to 50°F and is not significant, as defined in 10CFR50.46(a)(3)(i)

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