ML20195C304
| ML20195C304 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 05/28/1999 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20195C303 | List: |
| References | |
| NUDOCS 9906080062 | |
| Download: ML20195C304 (7) | |
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Annual Report on ABB CE Emergency Core Cooling System Performance Evaluation Models l
Waterford Steam Electric Station Unit 3 l
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9906090062 990528 ADOCK05000g2 DR i
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TABLE OF CONTENTS 1
- 1. 0 I N T R O D U C TI O N...................................................................... 1 2.0 ABB CE CODES USED FOR ECCS EVALUATION............................. 2 3.0 EVALUATION MODEL CHANGES AND ERROR CORRECTIONS...... 2
- 4. 0 C O N C L U S I O N S.............................................................................. 3
- 5. 0 R E F E R E N C E S.......................................................................,..... 4 l
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1.0 INTRODUCTION
This report addresses the NRC requirement to report changes or errors in Emergency Core Cooling System (ECCS) performance evaluation models. The ECCS Acceptance Criteria (Reference 1) gives reporting requirements and actions required when errors are corrected or changes are made in an evaluation model or in the application of a i
model for the holder of an operating license or construction permit of a nuclear power plant.
The action requirements in 10 CFR 50.46(a)(3) are:
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Each applicant for or holder of an operating license or construction permit shall estimate the effect of any change to or error in an acceptable evaluation model or in the application of such a model to determine if the change or error is significant. For this purpose, a significant change or error is one which results in a calculated peak fuel cladding temperature different by more than 50*F from the temperature calculated for the limiting transient using the last acceptable model, or is a cumulation of changes and errors such that the sum of the absolute magnitudes of the respective temperature changes is greater than 50 F.
2.
For each change to or error discovered in an acceptable evaluation model or in the application of such a model that affects the temperature i
calculation, the applicant or licensee shall report the nature of the change or error and its estimated effect on the limiting ECCS analysis to the i
Commission at least annually as specified in 10 CFR 50.4.
3.
If the change or error is significant, the applicant or licensee shall provide a report within 30 days and include with the report a proposed schedule for providing a reanalysis or taking other action as may be needed to show compliance with 10 CFR 50.46 requirements. This schedule may be developed using an integrated scheduling system previously approved for the facility by the NRC. For those facilities not using an NRC approved integrated scheduling system, a schedule will be established by the NRC staff within 60 days of receipt of the proposed schedule.
4.
Any change or error correction that results in a calculated ECCS performance that does not conform to the criteria set forth in paragraph (b) of 10 CFR 50.46 is a reportable event as described in 10 CFR 50.55(e),50.72 and 50.73. The affected applicant or licensee shall propose immediate steps to demonstrate compliance or bring plant design or operation into compliance with 10 CFR 50.46 requirements.
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' This report documents all of the corrected errors and/or changes made to the presently licensed ABB CE ECCS performance evaluation models for the Waterford LOCA analyses l This document is provided to satisfy the reporting requirements of the second item above. ABB CE reports for previous years are given in References 2 -12.
2.0-ABB CE CODES USED FOR ECCS EVALUATION ABB CE uses several digital computer codes for ECCS performance analysis that are described in topical reports, are licensed by the NRC, and are covered by the provisions of 10 CFR 50.46. The computer codes used for Large Break (LB) LOCA calculations are CEFLASH-4A, COMPERC-II, HCROSS, PARCH, STRIKIN-II, and i
COMZlRC. CEFLASH-4AS is used in conjunction with COMPERC-II, STRIKIN-il, and PARCH for Small Break (SB) LOCA calculationsc The codes for post-LOCA Long Term Cooling analysis are BORON, CEPAC, NATFLOW, and CELDA.
3.0 EVALUATION OF MODEL CHANGES AND ERROR CORRECTIONS This section discusses error corrections and model changes to the ABB CE ECCS performance evaluation models that may affect the calculated peak cladding
.-temperature.
Large Break LOCA The sum of the absolute magnitude of peak cladding temperature changes reported by ABB CE for LBLOCA, excluding the effects of changes to facility / fuel inputs evaluated under the provisions of 10 CFR 50.59, remained less than 1 F in 1998.
J On September 2,1998, EOl reported a condition in which an error in the energy i
redistribution factors used in the Waterford LBLOCA analysis resulted in exceeding the criteria for peak cladding temperature ~given in 10 CFR 50.46(b)(1) (Reference 13).
Immediate corrective action was taken by installing a penalty factor of 0.2 kw/ft for the Peak Linear Heat Generation Rate (PLHGR) in the plant's Core Operating Limit Supervisory System (COLSS) as recommended by the vendor (ABB CE). Since that time, a reanalysis of the LBLOCA has been performed under the provisions of 10 CFR 50.59 for Waterford's tenth operating cycle This analysis incorporated corrected energy _ redistribution factors to address the previously reported errors. EOl concluded from this analysis that the design of the Waterford ECCS for LBLOCA conformed to the ECCS acceptance criteria of 10 CFR 50.46. Thus, the total LBLOCA impact of model changes for Waterford remains less than 1 F.
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E Small Break LOCA The sum of the absolute magnitude of peak cladding temperature changes reported by ABB CE for SBLOCA, excluding the effects of changes to facility / fuel inputs evaluated under the provisions of 10 CFR 50.59, remained less than 3"F in 1998.
On January 5,1998, EOl reported a condition at Waterford in which the application of a changed ECCS SBLOCA model input (maximum High Pressure Safety injection flow) resulted in exceeding 10 CFR 50.46 acceptance criteria (Reference 14). In accordance with 10 CFR 50.46(a)(3)(ii), EOl submitted a reanalysis to the NRC staff for SBLOCA using the new ABB CE Supplement 2 ECCS Model(Reference 15). Subsequently, EOl submitted license amendment request NPF-38-208 (Reference 16) to the NRC staff to replace the reference to Supplement 1 in Technical Specification 6.9.1.11.1 with a reference to Supplement 2 of the " Calculative Methods for the CE Small Break LOCA Evaluation Model." Based on the results of the reanalysis submitted in Reference 15, EOl concluded that the design of the Waterford ECCS for SBLOCA conformed to the ECCS acceptance criteria of 10 CFR 50.46. Thus, the total SBLOCA impact of model changes for Waterford remains less than 3 F.
Post-LOCA Long Term Cooling No changes or errors were reported by ABB CE in the post-LOCA Long Term Cooling evaluation model.
4.0 CONCLUSION
S The sum of the absolute magnitude of the effects of model changes on the calculated peak cladding temperature for LBLOCA, excluding the effects of changes to facility / fuel inputs, remained less than 1*F relative to the 50*F criterion for a significant change in peak cladding temperature. The sum of the absolute magnitude of the effect of model changes on the calculated peak cladding temperature for SBLOCA, excluding facility / fuel inputs, remained less than 3*F in 1998. The effects of facility / fuel inputs are not included in this report since they are evaluated under the provisions of 10 CFR 1
50.59. No changes or errors were reported by ABB CE in the post-LOCA Long Term Cooling. evaluation model in 1998. Thus, no actions beyond this annual report are required by the criteria of 10 CFR 50.46.
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5.0 REFERENCES
i.
" Acceptance Criteria for Emergency Core Cooling Systems for Light Water Nuclear Power Reactors," Code of Federal Regulations, Title 10, Part 50, Section 50.46.
2.
" Annual Report on C-E ECCS Codes and Methods for 10 CFR50.46," CENPD-279, April 1989.
3.
" Annual Report on C-E ECCS Codes and Methods for 10 CFR50.46," CENPD-279, Supplement 1, February 1990.
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" Annual Report on C-E ECCS Codes and Methods for 10 Crit 50.46," CENPD-279, Supplement 2, April 1991.
5.
" Annual Report on C-E ECCS Codes and Methods for 10 CFR50.46," CENPD-279, Supplement 3, April 1992.
6.
" Annual Report on C-E ECCS Codes and Methods for 10 CFR50.46," CENPD-279, Supplement 4, April,1993.
7.
" Annual Report on C-E ECCS Codes and Methods for 10 CFR50.46," CENPD-279, Supplement 5, February 1994.
8.
" Annual Report on ABB C-E ECCS Performance Evaluation Models," CENPD-279, Supplement 6, February 1995.
9.
" Annual Report on ABB C-E ECCS Performance Evaluation Models," CENPD-279, Supplement 7, February 1996.
10.
" Annual Report on ABB CE ECCS Performance Evaluation Models,"CENPD-279, Supplement 8, March,1997.
11.
" Annual Report on ABB CE ECCS Performance Evaluation Models,"CENPD-279, Supplement 9, February 1998.
12.
" Annual Report on ABB CE ECCS Performance Evaluation Models,"CENPD-279, Supplement 10, April 1999.
13.
Entergy Operations Letter from E.C. Ewing to U.S. NRC, " Reporting of Licensee Event Report 98-017-00," W3F1-98-0145, September 2,1998.
14.
Entergy Operations Letter from E.C. Ewing to U.S. NRC, " Reporting of Licensee Event Report 97-033-00," W3F1-97-0286, January 5,1998.
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Entergy Operations Letter from E.C. Ewing to U.S. NRC, "Small Break Loss-of-.
Coolant Accident Emergency Core Cooling System Performance Analysis Using the ABB/CE Supplement 2 Model," W3F1-98-0090, April 30,1998.
116.'. Entergy Operations Letter from C.M. Dugger to U.S. NRC, " Technical Specification Change Request NPF-38-208,* W3F1-98-0108, July 29,1998.
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