An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model
Since the 1988 amendment of the 10 CFR 50.46 rule in 1988, Westinghouse has been developing and applying realistic or best-estimate methods to perform LOCA safety analyses. A realistic analysis requires the execution of various realistic LOCA transient simulations where the effect of both model and...
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| Format: | Article |
| Language: | English |
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Wiley
2008-01-01
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| Series: | Science and Technology of Nuclear Installations |
| Online Access: | http://dx.doi.org/10.1155/2008/498737 |
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| author | Cesare Frepoli |
| author_facet | Cesare Frepoli |
| author_sort | Cesare Frepoli |
| collection | DOAJ |
| description | Since the 1988 amendment of the 10 CFR 50.46 rule in 1988, Westinghouse has been developing and applying realistic or best-estimate methods to perform LOCA safety analyses. A realistic analysis requires the execution of various realistic LOCA transient simulations where the effect of both model and input uncertainties are ranged and propagated throughout the transients. The outcome is typically a range of results with associated probabilities. The thermal/hydraulic code is the engine of the methodology but a procedure is developed to assess the code and determine its biases and uncertainties. In addition, inputs to the simulation are also affected by uncertainty and these uncertainties are incorporated into the process. Several approaches have been proposed and applied in the industry in the framework of best-estimate methods. Most of the implementations, including Westinghouse, follow the Code Scaling, Applicability and Uncertainty (CSAU) methodology. Westinghouse methodology is based on the use of the WCOBRA/TRAC thermal-hydraulic code. The paper starts with an overview of the regulations and its interpretation in the context of realistic analysis. The CSAU roadmap is reviewed in the context of its implementation in the Westinghouse evaluation model. An overview of the code (WCOBRA/TRAC) and methodology is provided. Finally, the recent evolution to nonparametric statistics in the current edition of the W methodology is discussed. Sample results of a typical large break LOCA analysis for a PWR are provided. |
| format | Article |
| id | doaj-art-3da9d1ed71bf425b96edd467b83360bc |
| institution | Kabale University |
| issn | 1687-6075 1687-6083 |
| language | English |
| publishDate | 2008-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Science and Technology of Nuclear Installations |
| spelling | doaj-art-3da9d1ed71bf425b96edd467b83360bc2025-08-20T03:55:40ZengWileyScience and Technology of Nuclear Installations1687-60751687-60832008-01-01200810.1155/2008/498737498737An Overview of Westinghouse Realistic Large Break LOCA Evaluation ModelCesare Frepoli0LOCA Integrated Services I, Westinghouse Electric Company, Pittsburgh, PA 15230-0350, USASince the 1988 amendment of the 10 CFR 50.46 rule in 1988, Westinghouse has been developing and applying realistic or best-estimate methods to perform LOCA safety analyses. A realistic analysis requires the execution of various realistic LOCA transient simulations where the effect of both model and input uncertainties are ranged and propagated throughout the transients. The outcome is typically a range of results with associated probabilities. The thermal/hydraulic code is the engine of the methodology but a procedure is developed to assess the code and determine its biases and uncertainties. In addition, inputs to the simulation are also affected by uncertainty and these uncertainties are incorporated into the process. Several approaches have been proposed and applied in the industry in the framework of best-estimate methods. Most of the implementations, including Westinghouse, follow the Code Scaling, Applicability and Uncertainty (CSAU) methodology. Westinghouse methodology is based on the use of the WCOBRA/TRAC thermal-hydraulic code. The paper starts with an overview of the regulations and its interpretation in the context of realistic analysis. The CSAU roadmap is reviewed in the context of its implementation in the Westinghouse evaluation model. An overview of the code (WCOBRA/TRAC) and methodology is provided. Finally, the recent evolution to nonparametric statistics in the current edition of the W methodology is discussed. Sample results of a typical large break LOCA analysis for a PWR are provided.http://dx.doi.org/10.1155/2008/498737 |
| spellingShingle | Cesare Frepoli An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model Science and Technology of Nuclear Installations |
| title | An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model |
| title_full | An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model |
| title_fullStr | An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model |
| title_full_unstemmed | An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model |
| title_short | An Overview of Westinghouse Realistic Large Break LOCA Evaluation Model |
| title_sort | overview of westinghouse realistic large break loca evaluation model |
| url | http://dx.doi.org/10.1155/2008/498737 |
| work_keys_str_mv | AT cesarefrepoli anoverviewofwestinghouserealisticlargebreaklocaevaluationmodel AT cesarefrepoli overviewofwestinghouserealisticlargebreaklocaevaluationmodel |