ML041070377

Annual Reporting of Changes to and Errors in Emergency Core Cooling System Models or Applications

ML041070377
Person / Time
Site:	Millstone
Issue date:	04/08/2004
From:	Hartz L Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
04-167
Download: ML041070377 (7)

Text

lk 7

Dominion Nuclear Connecticut, Inc.

Millhtonr Power Station borninion Rope Ferry Road W~itcrford,C'1.06385 A p r i l 8, 2004 US. Nuclear Regulatory Commission Serial No: 04-167 Attention: Document Control Desk NL&OS/PRW: RO Washington, DC 20555 Docket No: 50-423 License No: NPF-49 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3 2003 ANNUAL REPORTING OF CHANGES TO AND ERRORS IN EMERGENCY CORE COOLING SYSTEM MODELS OR APPLICATIONS In accordance with 10 CFR 50.46(a)(3)(ii), Dominion Nuclear Connecticut, Inc. (DNC) hereby submits the annual summary of changes to and errors identified in the Emergency Core Cooling System (ECCS) evaluation models or applications of those models for Millstone Power Station Unit 3. transmits the annual report for the period January 2003 through December 2003. The following is a synopsis of the information provided in Attachment 1.

1. In a notification dated October 31, 2003, Westinghouse identified corrections in the NOTRUMP small break loss of coolant accident (SBLOCA) ECCS Evaluation model to resolve some inconsistencies in several drift flux models as well as the nodal bubble rise / droplet fall models. Plant specific calculations using the NOTRUMP code demonstrated that implementation of the corrections resulted in a conservative peak cladding temperature (PCT) impact of 0°F for Millstone Unit 3. Westinghouse identified this item as a non-discretionarychange with a PCT impact. Although the PCT impact is 0°F for Millstone Unit 3, Westinghouse recommendedthat this item be shown on the SBLOCA Margin Utilization Sheet provided in Attachment 1.

2. Westinghouse identified the following errors or changes in the ECCS Evaluation models applicable to Millstone Unit 3. Each was evaluated to have a PCT impact of 0°F:

a. BART Quench Model Calculations

b. BASHER Calculation of BASH Metal Heat Inputs C. Inconsistencies in Vessel Geometric Input Data

d. LOCBART Fuel Rod Plenum Modeling

e. LOCBART Grid Mass Balance

f. NOTRUMP Drift Flux Model Inconsistencies

9. NOTRUMP Inverted T-Node Sign Convention

h. NOTRUMP Vapor Region Formation Logic

Serial Number 04-167 Millstone Power Station Unit 3 Annual ECCS Report Page 2 of 3 I. SBLOCTA Burst Logic I. SBLOCTA ZIRLOTMCladding Creep Constants

k. SATIMP/SPADES Updates I. SBLOCTA Oxide-to-Metal Ratio

m. SBLOCTA Gap Conductance Model

n. General Code Maintenance (Appendix K)

Westinghouse identified these items as non-discretionary changes with no PCT impact and recommended that these items not be shown on the Margin Utilization Sheets provided in Attachment 1.

Considering the changes summarized in Attachment 1, the corrected PCTs for the limiting SBLOCA (2106°F) and large break loss of coolant accident (LBLOCA) (2004°F) remain below the 2200°F limit as defined by 10 CFR 50.46(b)(l).

This information satisfies the 2003 annual reporting requirements of 10CFR50.46(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 additional questions concerning this submittal, please contact Mr. Paul R.

Willoughby at (804) 273-3572.

Very truly yours, Leslie N. Hartz Vice President - Nuclear Engineering Attachment (1)

Serial Number 04-167 Millstone Power Station Unit 3 Annual ECCS Report Page 3 of 3 Commitments made in this letter: None cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 Mr. V. Nerses Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 8C2 Rockville, MD 20852-2738 Mr. S. M. Schneider NRC Senior Resident Inspector Millstone Power Station

Serial Number 04-167 Millstone Power Station Unit 3 Annual ECCS Report ATTACHMENT 1 MILLSTONE POWER STATION UNIT 3 2003 ANNUAL REPORTING OF 10 CFR 50.46 MARGIN UTILIZATION

Serial Number 04-167 Millstone Power Station Unit 3 Annual ECCS Report Attachment 1 Page 1 of 3 10 CFR 50.46 Margin Utilization Small Break LOCA Plant Name: Millstone Power Station, Unit 3 Utilitv Name: Dominion Nuclear Connecticut. Inc.

Analvsis Information EM: NOTRUMP Limiting Break Size: 3 Inches Analysis Date: 06/90 FQ: 2.6 FAH: 1.7 Fuel: Vantage 5H SGTP (%): 10 Notes: None Clad Temp ( O F ) Notes LICENSING BASIS Analysis of Record PCT 1891 MARGIN ALLOCATIONS (Delta PCT)

A. Prior Permanent ECCS Model Assessments

1. ECCS Evaluation Model Changes 27

2. Effect of SI in Broken Loop 150

3. Effect of Improved COSl (Condensation Model) -150

4. Drift Flux Flow Regime Errors -13

5. Average Rod Burst Strain Limit 14

6. Fuel Rod Burst Strain Limit -14

7. LUCIFER Error Corrections -16

8. Boiling Heat Transfer Correlation Error -6

9. Steam Line Isolation Logic Error 18

10. Axial Nodalization, RIP Model Revision, and SBLOCTA Error Corrections Analysis 26

11. NOTRUMP Specific Enthalpy Error 20

12. SBLOCTA Fuel Rod Initialization Error 10

13. MSSV 3% Setpoint Uncertainty Analysis 67

14. AFW Purge Volume Error 17

15. NOTRUMP Mixture Level Tracking/Region Depletion Errors 13 B. Planned Plant Change Evaluations

1. Increased Pressurizer Pressure Uncertainty 14

2. ZIRLOTMCladding Evaluation 24

3. Fuel Rod Crud 2

4. Reduced Thermal Design Flow 12

5. Fuel Reconstitution 1

6. Revised T-hot Average Scaling 2 C. 2003 Permanent ECCS Model Assessments

1. NOTRUMP Bubble Rise / Drift Flux Model Inconsistency Corrections 0 D. Temporary ECCS Model Issues

1. None 0

Serial Number 04-167 Millstone Power Station Unit 3 Annual ECCS Report Attachment 1 Page 2 of 3 10 CFR 50.46 Margin Utilization Small Break LOCA (Continued)

Clad Temp ( O F ) Notes E. Other Margin Allocations

1. Burst and Blockagenime in Life

2. Axial Offset Decrease to +20%

3. Margin Recovery Benefit LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2106 Notes:

(1 ) This assessment is a function of Base PCT plus permanent margin allocation and as such will increase/decrease with margin allocation changes.

(2) Margin Recovery Benefit based in part on plant-specific PCT calculationsthat identify margin in Model Assessments and Planned Plant Change Evaluations reported in Sections

< A 7 and U B 7 .

(3) Value includes previous Burst and Blockagenime in Life penalty, SPIKE Correlation Revision penalty (1999 Annual Report), and consideration of new penalty due to Item A.15 (NOTRUMP Mixture Level Tracking/Region Depletion Errors).

Serial Number 04-167 Millstone Power Station Unit 3 Annual ECCS Report Attachment 1 Page 3 of 3 10 CFR 50.46 Margin Utilization Large Break LOCA Plant Name: Millstone Power Station, Unit 3 Utilitv Name: Dominion Nuclear Connecticut, Inc.

Analvsis Information EM: BASH Limiting Break Size: Cd=0.6 Analysis Date: 08/90 FQ: 2.6 FAH: 1.7 Fuel: Vantage 5H SGTP (%): 10 Notes: VH5/RFA Clad Temp ( O F ) -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. 2003 Permanent ECCS Model Assessments

1. None 0 D. Temporary ECCS Model Issues

1. None 0 E. Other Margin Allocations

1. Rebaseline of AOR 30 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT= 2004