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

Dominion Nuclear Connecticut, Inc.

Millhtonr Power Station Rope Ferry Road W~itcrford, C'1.06385 A p r i l 8, 2004 US. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 lk 7 borninion Serial No:

04-1 67 NL&OS/PRW:

RO 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-discretionary change with a PCT impact. Although the PCT impact is 0°F for Millstone Unit 3, Westinghouse recommended that 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.

b.

d.

e.

f.

9.

h.

C.

BART Quench Model Calculations BASHER Calculation of BASH Metal Heat Inputs Inconsistencies in Vessel Geometric Input Data LOCBART Fuel Rod Plenum Modeling LOCBART Grid Mass Balance NOTRUMP Drift Flux Model Inconsistencies NOTRUMP Inverted T-Node Sign Convention NOTRUMP Vapor Region Formation Logic

Serial Number 04-1 67 Millstone Power Station Unit 3 Annual ECCS Report Page 2 of 3 I.

SBLOCTA Burst Logic I.

k.

SATIMP/SPADES Updates I.

SBLOCTA Oxide-to-Metal Ratio

m.

SBLOCTA Gap Conductance Model

n.

SBLOCTA ZIRLOTM Cladding Creep Constants 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 1 OCFR50.46(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 04-1 67 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 19406-141 5 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 04-1 67 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 04-1 67 Millstone Power Station Unit 3 Annual ECCS Report Page 1 of 3 10 CFR 50.46 Margin Utilization Small Break LOCA Plant Name:

Utilitv Name:

Millstone Power Station, Unit 3 Dominion Nuclear Connecticut. Inc.

Analvsis Information EM:

NOTRUMP Limiting Break Size:

3 Inches Analysis Date:

06/90 FQ:

2.6 FAH:

1.7 Notes

None Fuel:

Vantage 5H SGTP (%):

10 Clad Temp ( O F )

Notes LICENSING BASIS Analysis of Record PCT MARGIN ALLOCATIONS (Delta PCT)

A.

B.

C.

D.

Prior Permanent ECCS Model Assessments

1.

ECCS Evaluation Model Changes

2.

Effect of SI in Broken Loop

3.

Effect of Improved COSl (Condensation Model)

4.

Drift Flux Flow Regime Errors

5.

Average Rod Burst Strain Limit

6.

Fuel Rod Burst Strain Limit

7.

LUCIFER Error Corrections

8.

Boiling Heat Transfer Correlation Error

9.

Steam Line Isolation Logic Error

10.

Axial Nodalization, RIP Model Revision, and SBLOCTA Error Corrections Analysis

11.

NOTRUMP Specific Enthalpy Error

12.

SBLOCTA Fuel Rod Initialization Error

13.

MSSV 3% Setpoint Uncertainty Analysis

14.

AFW Purge Volume Error

15.

NOTRUMP Mixture Level Tracking/Region Depletion Errors Planned Plant Change Evaluations

1.

Increased Pressurizer Pressure Uncertainty

2.

ZIRLOTM Cladding Evaluation

3.

Fuel Rod Crud

4.

Reduced Thermal Design Flow

5.

Fuel Reconstitution

6.

Revised T-hot Average Scaling 2003 Permanent ECCS Model Assessments

1.

NOTRUMP Bubble Rise / Drift Flux Model Inconsistency Corrections Temporary ECCS Model Issues

1.

None 1891 27 150

-1 50

-1 3 14

-1 4

-1 6

-6 18 26 20 10 67 17 13 14 24 2

12 1

2 0

0

Serial Number 04-1 67 Millstone Power Station Unit 3 Annual ECCS Report Page 2 of 3 10 CFR 50.46 Margin Utilization Small Break LOCA (Continued)

Notes Clad Temp ( O F )

E.

Other Margin Allocations

1.

2.

3.

Margin Recovery Benefit Burst and Blockagenime in Life Axial Offset Decrease to +20%

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 calculations that 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 (1 999 Annual Report), and consideration of new penalty due to Item A.15 (NOTRUMP Mixture Level Tracking/Region Depletion Errors).

Serial Number 04-1 67 Millstone Power Station Unit 3 Annual ECCS Report Page 3 of 3 10 CFR 50.46 Margin Utilization Large Break LOCA Plant Name:

Utilitv Name:

Millstone Power Station, Unit 3 Dominion Nuclear Connecticut, Inc.

Analvsis Information EM:

BASH Limiting Break Size:

Cd=0.6 Analysis Date:

08/90 FQ:

2.6 FAH:

1.7 Notes

VH5/RFA LICENSING BASIS Fuel:

Vantage 5H SGTP (%):

10 Clad Temp ( O F ) -

Notes Analysis of Record PCT 1974 MARGIN ALLOCATIONS (Delta PCT)

A.

Prior Permanent ECCS Model Assessments 1.

None B.

Planned Plant Change Evaluations

1.

None C.

2003 Permanent ECCS Model Assessments

1.

None D.

Temporary ECCS Model Issues

1.

None E.

Other Margin Allocations

1.

Rebaseline of AOR 0

0 0

0 30 LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT=

2004