ML20211M452

Forwards Rept Covering Changes or Errors in Evaluation Models Applicable to Plant for Year Ending 970831,IAW 10CFR50.46(a)(3)(ii)

ML20211M452
Person / Time
Site:	McGuire, Mcguire
Issue date:	10/02/1997
From:	Barron H DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9710140223
Download: ML20211M452 (15)

Text

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Duke Power Company s

A ikk two tom)wy hhnuite Nuclear Station alas.,c,

!2700 ilapis Icary Roast Ilunternille, NC 2h078 9340 (704) 8754iMI Octobar 2, 1997 9

U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.

20555

Subject:

McGuire Nuclear StatJon Docket Nos. 50-369, 50-370 Report Pursuant to 10CFR50.46, Changes to or Errors in an ECCS Evaluation Model 10CFR50. 4 6 (a) (3 ) (ii) requires reporting of changes or errors in ECCS evaluation models(EM) or errors in the application of ems. LOCA analysis in support of McGuire operation

.O supplied by Framatome, Technologies, Inc. and Westinghouse, Electric Corporation.

The attached report covers changes or errors in ems applicable to McGuire for the year ending August 31, 1997.

Questions should be directed to Kay Crane at(704) 875-4306.

p

//L H. B. Barton McGuire Nuclear Station cc Mr. Victor Nerses, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington,-D.C.

20555 Mr. Luis Reyes, Regional Administrator 1

U.S. Nuclear Regulatory Commission, Region II h-Atlanta Federal Center j

61 Forsyth St.,

SW, Suite 23T85 A' lanta, Georgia, 30303 l

g

~Mr. Scott Shaeffer Senior Resident Inspection-McGuire Nuclear Station 9710140223 971002 PDR ADOCK 05000369 P

PDR u

By letter dated February 17, 1997 (attached), Westinghouse provided a list and brief description of the ECCS small break LOCA EM changes and errors that affect the PCT results for McGuire and Catawba.

The impact of these small break LOCA EM changes and errors have been incorporated into McGuire's revised LOCA peak clad temperature margin utilization sheets.

The revised maximum PCT is 14 50'F (an increase of 34'F).

FTI performed a reanalysis of the small break LOCA for replacement steam generators at McGuire using the recently l

approved SBLOCA evaluation model, BAW-10168, Revision 2.

The results of this analysis are a maximum PCT of 1254*F (an increase of 5 4'F),

a maximum local cladding oxidation fraction of 0.284%, and a total core metal-water reaction of loss than 0.03%.

By letter dated July 25, 1997, Duke Energy notified the NRC of an decay heat error in the FTI LOCA EM.

The error resulted in a

change in PCT greater than 50*F.

FTI I

reanalyzed the large break LOCA analyses of record for McGuire and determined an ine ;'ase in PCT of 77'F for Unit 1 and 20'F for Unit 2.

Th. small break LOCA reanalyses resulted in an increase in PCT of 89 F (1343*F).

LOCA analyses for McGuire with the FTI EM decay heat error correction are in place, the results meet the acceptance criteria of 10CFR50.46.

Core power distribution monitoring is being performed with Core Operating Limit Report limits consistent with these models.

'I w

l Westinghouse Energy Systems a u sss Electric Corporation Pmtugh Pennshanie 16224355 Febmary 17,1997 DPC 97 203 Mr. T. E. Ryan, Manager Operating Experi< ice Assessment Duke Power Company P.O. Box 1006 Charlotte, Nonh Carolina 28201 1006 Mail Code: EC05N Duke Power Company McGuire Units 1 & 2, Catawba Units 1 & 2 10 CFR 50.46 Annual Notification and Reponine

Dear Mr. Ryan:

This is a notification of 10 CFR 50.46 reporting information pnaining to Westinghouse ECCS Evaluation Models. As committed to in WCAP-13451. Westmghour,e Methodology for Implementation of 10 CFR 50.46 Reponing, attached is a list and brief description of the Emergency Core Cooling System (ECCS) Evaluation Model changes and errors for the 1996 year that affect the Peak Cladding Temperature for your plant (s) (Attachment 1). These Evaluation Model changes and errors will be reponed to the NRC via Westinghouse letter NSD NRC 97-4983.

Evaluation Model changes and errors have been incorporated into Section D of your revised LOCADe Peak Clad Temperature (PCT) Margin Utilir.ation Sheets (Attachment 2). This information is for your use in making a determination relat ve to reporting requirements of 10 CFR 50.46.

If you have any questions conceming this letter, please contact me at (412) 374 3350.

Very truly yours,

<(,v. A %

K.B.llanahan Account Manager Attachnwnt 0147 1 14 3

13 i

3 1996 Annual 10 CFR 50.46 Report Of Changes Affecting PCT 4

4

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SBLOCTA FUEL ROD INITIALIZATION i

Backaround An error was discovered in the SBLOCTA code related to adjustments which are made as r

part of the fuel rod initiallation process which is used to obtain agree wnt between the

(

SBLOCTA model and the fuel data supplied from the fuel thermal hydraulle design i

calculations at full power, steady: state conditions. Specifically, an adjustment to the power, which is made to compensate for adjustments to the assumed pellet diameter was incorrect.

}

Additionally, updates were made to the fuel rod clad creep and strain model to correct logic errors that could occur in certain transient conditions. These model revisions also had a small 3

affect on the fuel rod initialization process, and can produce small affects during the transient.

Due to the small magnitude of affects, aad the interaction between the two items, they are being evaluated as a single, closely related affect.

l This change is considered to be a Non Discretionary Change as described in WCAP 13451.

Affected Evaluation Models

{

1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP Estimated Effects Representative plant calculations with the corrected model demonstrated that these revisions result in a predicted peak clad temperature increase on the order of +10 'F. This 10 'F penalty has been assessed against all existing analyses of record with the above model.

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TRANSLATION OF FLUID CONDITIONS FROM SATAN TO LOCTA I

f

Background

An error was discovered in the coding related to the translation of fluid conditions between the l

SATAN blowdown hydrr iles code and the LOCTA code use:1 for subchannel analysis of the fuel rods. In performing a4ial interpolations to translate the SATAN fluid conditions onto the mesh l

nodalization used by the LOCTA code, the length of the lower core channel 0 d connection to the i

lower plenum node was incorrectly calculated.

This change is considered to be a Non Discretionary Change as descrit d in WCAP 13451,

d I

Affected Evaluation Models

]

1981 Westinghouse Large Break LOCA Evaluation Model i

1981 Westinghouse Large Break LOCA Evaluation Model with BART l

1981 Westinghouse Large Break LOCA Evaluation Model with BASH Estimated Effects Reprer.entative plant calculations with the corrected model demonstrated that this correction resulted in approximately a il5 'F effect on the BASH '.arge break LOCA evaluation model. Evaluations based on these studies conclude that the effect on the BART and 1981 evaluation models was a 5'F benefit, i

Therefore the following estimated effects are assigned:

BASH EM 15'F penalty j

BART and 1981 EM 5'F benefit.

4 e

. b.

- LOOP SEAL ELEVATION ERROR Backcround An error was discovered in raw plant geometric data that supports input to the Evaluation Model codes. The erroneous datum was a term associated with the relative elevation of the crossover leg.

This change is considered to be a Non Discretionary Change as described in WCAP-13451.

Affected Evaluation Models 1985 Westinghouse Small Break LOCA Evaluation Model Using NOTRUMP 1981 Westinghouse Large Break LOCA Evaluation Model 1981 Westinghouse Large Break LOCA Evaluation Model Using BART 1981 Westinginouse Large Break LOCA Evaluation Model Using BASH Estimated Effects The erroneous elevation terms are estimated to have a negligible effect on Large Break LOCA Evaluation Model calculations. Representative sensitivity calculations with NOTRUMP have determined that a non-significant PCT cffect is to be expected due to the influence of the erroneous elevation on the loop seal clearing process. PCT cffects ranging from -44'F to +24'F have been assigned to affected plants depending on the magnitude and direction of the error.

1996 Annual 10 CFR 50.46 Report Peak Clad Temperature Margin Utilization Sheets 1

L k

S mall B reak Peak. Clad.TemperaturcRatginjitilization Revision Date: 02/10/97 Plant Name: McGuire Units 14 2 Eval.Model: NOTRUMP Fuel: OFA Utility Name: Duke Power Company FQ=2.32 FdH=1.55 SOTP=l8%

Reference

• Clad Temperature Notes A; ANALYSIS OF RECORD (3/93)

PCT =

1264 'F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS 1,2,3,5 APCT=

152 'F C.10 CFR K,19 SAFETY EVALUATIONS Table A APCT=

0 *F D.199610 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

1. SBLOCTA Fuel Rod initialization Error 6

A PCT =

10*F

2. Loop Seal Elevation Error 6

APCT=

24 'F E. TEMPORARY ECCS MODELISSUES"

1. None APCT=

0 'F F. OTHER MARGIN ALLOCATIONS

1. None APCT=

0 'F LICENSING BASIS PCT + MARGIN ALLOCATH NS PCT =

1450 'F

• References for the Peak Clad Temperature Margin Utilization summary can be found in Table B.

• • It is recommended that these temporary PCT allocations which address current LOCA model issues not be considered with respect to 10 CFR 50.46 reporting requirements.

Notes:

None

. s.

Large Br9ak Peak Clad Temergure Margin Utilization _ _

Revision Date: 02/10/97 Plant Name: McGuire Units 1 & 2 Eval.Model: BASH Fuel: OFA Utility Name: Duke Power Company FQ=2.32 FdH=L55 SGTP=18%

Reference

• Clad Temperature Notes A. ANALYSIS OF RECORD (3/93)

PCT =

194f 'F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS 1,4,5 APCT=

23 'F 1,2 C.10 CFR 50.59 SAFETY EVALUATIONS Table A APCT=

0 *F D, 199610 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

1. Translation of Fluid Conditions from SATAN to LOCTA APCT=

15 'F E. TEMPORARY ECCS MODEL ISSUES"

1. None APCT=

0 'F F. OTHER MARGIN ALLOCATIONS

1. None APCT=

0 'F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT =

193 'F

• References for the Peak Clad Temperature Margin Utilization summaries can be found in Table B,

• • It is recommended that these temporary PCT allocations widch address current LOCA model issues not be considered with respect to 10 CFR 50,46 reponing requirements.

Notes:

1. The effect of BASH Hot Leg Nozzle gaps is O'F for the cosine case (PCT time = 70 seconds) and.203'F for the skewed shape case (PCT time = 242 seconds). As a result, the chopped cosine remains limiting when.

B ASH Hot Leg Nozzle gap credit is taken, and the appropriate PCT benefit is equal to the skewed power -

shape penalty of 48'F,

2. The Catawba sensitivity case reported in the 18% SGTP Program report was also evaluated for skewed power shapes and remains bounded by McGuire.

Tabic.A.10CFR50.51.SafetyIrnluations Revision Date: 02/10/97 Plant Name: McGuire Units I & 2 Utility Name: Duke Power Company Reference Clad Temperature Notes

1. SMALL BREAK ECCS SATETY EVALUATIONS A. None A PCT =

0 *F TOTAL 10 CFR 50.59 SMALL BREAK ASSESSMENTS PCT =

0 *F

11. LARGE BREAK ECCS SAFETY EVALUATIONS A. None APCT=

0 *F TOTAL 10 CFR 50,59 LARGE BREAK ASSESSMENTS PCT =

0 *F Notes:

Ncne l

Tabic.B1Rcittences m._

1. DPC-94 205, " Duke Power Company, McGuire Units I & 2, Catawba Units 1 & 2: 10 CFR 50.46 Notification and Reporting information," February 8,1994.

2. DPC-94-226,

• Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: 10 CFR 50.46 Notification and Reporting Information " August 18,1994.

3. DPC 94-229," Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: SBLOCTA Axial Nodalir.ation," October 27,1994.

4. DPC 95 224," Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: LOCA Axial Power Shape Sensitivity Model," August 14,1995.

' 5. DPC-96-202, " Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: 10 CFR 50.46 Annual Notifi and Reporting," February 9,1996.

6. DPC-96 218. " Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: 10 CFR 50.46 Small Break LOC Notification and Reporting," July 8,19%.

e

. Small Break PeaLClad_Temperaturcliargin. Utilization m

Revision Date: 02/10/97 Plant Name: Catawba Units 1 & 2 Eval.Model: NOTRUMP Fuel: OFA Utility Name: Duke Power Company

. FQ=2.32 FdH=1.55 SGTP=18%

Reference

• Clad Temperature Notes A. ANALYSIS OF RECORD (3/93)

PCT =

1264 *F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS 1,2,3,5 4 PCT =

152 *F C.10 CFR 50.59 SAFETY EVALUATIONS Table A 4 PCT =

0 *F D.199610 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

1. SBLOCTA Fuel Rod initialization Error 6

APCr=

10 *F E. TEMPORARY ECCS MODEL ISSUES"

1. None APCT=

0 *F F. OTHER MARGIN ALLOCATIONS

1. None aPCT=

0 *F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT =

1426 *F

• References for the Peak Clad Temperature Margin Utilization summary can be found in Table B.

• • It is recommended that these temporary PCT allocations which address current LOCA model issues not be considered with respect to 10 CFR 50.46 reporting requirements.

Notes:

None m_

.g.

+

Large Break Peak _Cladlemperature Margin Utilization Revision Date: 02/10/97 Plant Name: Catawba Unit i Eval.Model: BASH Fuel: OFA Utility Name: Duke Power Company FQ=2.32 FdH=1.55 SGTP=18%

Reference

• Clad Temperature Notes A. ANALYSIS OF RECORD (3/93)

PCT =

1945 *F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS.

1,4,5 aPCT=

23 *F 1,2 C,10 CFR 50.59 SAFETY EVALUATIONS Table A A PCT =

0 *F D.199610 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

1. Translation of Fluid Conditions from SATAN to LOCTA APCT=

15 *F E. TEMPORARY ECCS MODEL ISSUES"

1. None APCT=

0 *F F. OTHER MARGIN ALLOCATIONS

1. None APCTt 0 *F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT =

1937 *F

• References for the Peak Clad Temperature Margin Utilization summaries can be found in Table B.

• • It is recommended that these temporary PCT allocations which address current LOCA model issues not be considered with respect to 10 CFR 50.46 reporting requirements.

Notes:

I, he effect of BASH Hot Leg Nozzle gaps is 0*F for the cosine case (PCT time = 70 seconds) and -203*F for the skewed shape case (PCT time = 242 seconds). As a result, the chopped cosine remains limiting when B ASH Hot Leg Nozzle gap credit is taken, and the appropriate PCT benefit is equal to the skewed power shape penalty of 48'F.

2. The Catawba sensitivity case reported in the 18% SGTP Program report was also evaluated for skewed power shapes and remains bounded by McGuire.

,e e

._,Jg-Btcak PrAk Clad Temperature Margin _ Utilization Revision Date: 02/10/97 Plant Name: Catawba Unit 2 Eval.Model: BASH Fuel: OFA Utility Name: Duke Power Company FQ=2.32 FdH=1.55 SGTP=l8%

Reference

• Clad Temperature Notes A. ANALYSIS OF RECORD (3/93)

PCT =

1945 *F B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS.

1.4.5 APCT=

-11 *F l.2 C.10 CFR 50.59 SAFETY EVALUATIONS Table A APCT=

0 *F D.199610 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)

1. Translation of Fluid Conditions from SATAN to LOCTA APCT=

15 *F E. TEMPORARY ECCS MODEL ISSUES"

1. None APCT=

0 *F F. OTHER MARGIN ALLOCATIONS APCT=

, O *F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT =

1949 *F

• References for the Peak Clad Temperature Margin Utilization summaries can be found in Table B.

" It is recommended that these temporary PCT allocations which address current LOCA model issues not be considered with respect to 10 CFR 50.46 reporting requirements.

Notes:

1. The effect of BASH Hot Leg Nozzle gaps is 0*F for the cosine case (PCT time = 70 seconds) and 203*F for the skewed shape case (PCT time = 242 seconds). As a result, the chopped cosine remains limiting when B ASH Hot Leg Nozzle gap credit is taken, and the appropriate PCT benefit is equal to the skewed power shape penalty of 48'F.

2. The Catawba sensitivity case reported in the 18% SGTP Program report was also evaluated for skewed power shapes and remains bounded by McGuire.

TabicA _10.CER.50J9_ Safety _Evaluatiofu

_m=.

Revision Date: 02/1097 Plant Name: Catawba Units 1 & 2 Utility Name: Duke Power Company Reference Clad Temperature Notes

1. SMALL BREAK ECCS SAFETY EVALUATIONS A. None APCT=

0 *F TOTAL 10 CFR 50J9 SMALL BREAK ASSESSMENTS PCT =

0 *F II, LARGE BREAK ECCS SAFETY EVALUATIONS A. None APCT=

0 *F TOTAL 10 CI'R 50.59 LARGE BREAK ASSESSMENTS PCT =

0 'F Notes:

None m ___

Table 3_ References

1. DPC 94 205," Duke Power Company McGuire Units 1 & 2, Catawba Units 1 & 2,10 CFR 50.46 Notification and Reporting Information," February 8,1994.

2. DPC-94-226,' Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 210CFR50.46 Notification and Reporting Information " August 18,1994.

3. DPC 94-229," Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: S3LOCTA Axial Nodalization," October 27,1994

4. DPC-95-224, " Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: LOCA Axial Power Shape Sensitivity Model," August 14,1995.

5. DPC-96-202, " Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: 10 CFR 50.46 Annual Notification and Reporting," February 9,19%.

6. DPC 96 218. " Duke Power Company, McGuire Units 1 & 2, Catawba Units 1 & 2: 10 CFR 50.46 Small Break LOCA Notification and Reporting," July 8,1996.

.