ML20148L996
| ML20148L996 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 12/31/1996 |
| From: | NORTHERN STATES POWER CO. |
| To: | |
| Shared Package | |
| ML20148L478 | List: |
| References | |
| NUDOCS 9706200166 | |
| Download: ML20148L996 (6) | |
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1 1996 Annual 10 CFR 50.46 Report Of Changes Affecting PCT i
4 9706200166 970612 PDR ADOCK 05000282 R
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SBLOCTA FUEL ROD INITIALIZATION
Background
An error was discovered in the SBLOCTA code related to adjustments which are made as part of the fuel rod initialization process which is used to obtain agreement between the SBLOCTA model and the fuel data supplied from the fuel thermal-hydraulic design calculations at full power, steady-state conditions. Specifically, an adjustment to the power, I
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 affect on the fuel rod initialization process, and can produce small affects during the transient.
Due to the small magnitude of affects, and the interaction between the two items, they are being evaluated as a single, closely related affect.
This change is considered to be a Non-Discretionary Change as described in WCAP-13451.
i Affected Evaluation Models 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP 1
i 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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l 1996 Annual 10 CFR 50.46 Report l
Peak Clad Temperature Margin Utilization Sheets M
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. _.__. _.___ _ Small3reak.fealtClad_Temperaturc_MarginHtilizatiofL Revision Date: 04/14/97 Plant Name; Prairie Island Units 1 and 2 Eval.Model: NOTRUMP Utility Name: Northern States Power Fuel: 14x14 OFA ZIRLO(TM)
FQ=2.80 FdH=2.00 SGTP=25%
Reference
- Clad Temperature Notes A. ANALYSIS OF RECORD (7/93) 1 PCT =
1195 *F 1
B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS 2
APCT=
-29 'F C.10 CFR 50.59 SAFETY EVALUAT10NS Table A APCT=
0 'F D.199610 CFR 50.46 MODEL ASSESSMENTS (Permanent Assessment of PCT Margin)
- l. SBLOCTA Fuel Rod Initialization Error aPCT=
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 =
1176 *F
- References for the Peak Clad Temperature Margin Utilization summary can be found in Table 3.
" It is recommended that these temporary PCT allocations which address current LOCA model Usues not be considered with respect to 10 CFR 50.46 reporting requirements.
Notes:
- 1. Includes annular pellet evaluation.
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_Large Break Peak Clad Temperature Mariin Utilization Revision Date: 04/14/97 Plant Name: Prairie Island Units I and 2 Eval.Model: SECY UPI l
Utility Name: Nortnern States Power Fuel: 14x!4 OFA ZIRLO(TM)
FQ=2.40 FdH=1.77 SGTP=15%
l Rarerence*
Clad Temperature Notes A. ANALYSIS OF RECORD (3/95) 3,4 PCT =
2180 *F 1
B. PRIOR PERMANENT ECCS MODEL ASSESSMENTS 2
APCT=
-175 *F.
C.10 CFR 50.59 SAFETY EVALUATIONS Table A APCT=
0 *F D.199610 CFR 50.46 MODEL ASSESSMENTS (Pennanent Assessment of PCT Margin)
- 1. None APCT=
0 *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 =
2005 *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. P-bar-HA increased from 1.57 to 1.59 j
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Table A_ _ ULCER 1A59_ Safely _Evaluationt..__
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Revision Date: 04/14/97 Plant Name: Prairie Island Units I and 2 Utility Name: Nonhern States Power Reference Clad Temperature Notes I. SMALL BREAK ECCS SAFETY EVALUATIONS APCT=
0 'F A. None TOTAL 10 CFR 50.59 SMALL BREAK ASSESSMENTS PCT =
0 'F II. LARGE BREAK ECCS SAFETY EVALUATIONS APCT=
0 *F
' A. None TOTAL 10 CFR 50.59 URGE BREAK ASSESSMENTS PCT =
0 *F Notes:
None Table _B - RcLercoces
- 1. NSP-93-521," Northern Power Company Prairie Island Units I and 2 Small Break Loss-of-Coolant Accident Final Engineering Report for the ZIRLO(TM) Fuel Upgrade," July 30,1993.
- 2. NSP-96-202, " Northern Power Company Prairie Island Units I and 210 CFR 50.46 Annual Notification and Reponing," February 20,1996.
- 3. 95NS-G-0021 " Updated UPI LBLOCA," March 24,1995,
- 4. WCAP-13919, Addendum 1. " Prairie Island Units I and 2 WCOBRAURAC Best Estimate UPI Large Break LOCA Analysis Engineering Report Addendum 1: Updated Results," December 1996.
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