STATE OF THE ART IN USING BEST ESTIMATE CALCULATION TOOLS IN NUCLEAR TECHNOLOGY

System thermal-hydraulic codes have been used in the past decades in the areas of design, operation, licensing and safety of Nuclear Power Plants (NPPs). The development and validation of these codes have reached a high degree of maturity, through the consideration of huge experiments and advanced numerical models. Nowadays, the analyses are based upon realistic approaches rather than the conservative evaluation models. However the applications of these computational tools require preliminary qualification issues. Although huge amounts of financial and human resources have been invested for the development and improvement of codes, the calculation results are still affected by errors. In the sophisticated nuclear technology, design and safety of NPP, these errors must be quantified. An overview of the state of the art of the current thermal-hydraulic system code is developed and the need of uncertainty analysis in code calculations is emphasized. Several sources of uncertainty have been classified and commented, and typical applications of such methods are shown.

[1]  Alessandro Petruzzi,et al.  Development, qualification and use of the CIAU method for internal assessment of uncertainty in system codes , 2005 .

[2]  Francesco Saverio D'Auria,et al.  Application of the CATHARE advanced code to numerical benchmark exercises , 1989 .

[3]  Soeren Kliem,et al.  Comprehensive uncertainty and sensitivity analysis for coupled code calculations of VVER plant transients , 2005 .

[4]  Francesco Saverio D'Auria,et al.  Good Practices for User Effect Reduction , 1998 .

[5]  Francesco Saverio D'Auria,et al.  Analysis of the Peach Bottom turbine trip experiment by coupled Relap5-Parcs 3D codes , 2003 .

[6]  Francesco Saverio D'Auria,et al.  Overview of Uncertainty Issues and Methodologies , 1998 .

[7]  Yun-Je Cho,et al.  EXPERIMENTAL STUDY ON MEASUREMENT OF EMISSIVITY FOR ANALYSIS OF SNU-RCCS , 2006 .

[8]  Francesco Saverio D'Auria,et al.  Three Mile Island Unit 1 Main Steam Line Break Three-Dimensional Neutronics/Thermal-Hydraulics Analysis: Application of Different Coupled Codes , 2003 .

[9]  S Belsito,et al.  Development of a statistical model for the evaluation of counterpart tests data base / Entwicklung eines statistischen Modells zur Berechnung von Daten für vergleichende Modellversuche , 1994 .

[10]  Francesc Reventos,et al.  Neutronics/Thermal-hydraulics Coupling in LWR Technology – CRISSUE-S WP2: State-of-the-Art Report , 2004 .

[11]  Francesco Saverio D'Auria,et al.  Establishment of an applicable version of the CIAU methodology , 2005 .

[12]  Francesco Saverio D'Auria,et al.  Code validation and uncertainties in system thermalhydraulics , 1998 .

[13]  Francesco Saverio D'Auria,et al.  State of the Art Report on Boiling Water Reactor Stability (SOAR ON BWRS) , 1997 .

[14]  Francesco Saverio D'Auria,et al.  Thermohydraulics of Emergency Core Cooling in Light Water Reactors - A State-of-the-Art Report. CSNI Report , 1989 .

[15]  Francesco Saverio D'Auria,et al.  User Effects on the Thermalhydraulic Transient System Codes Calculations , 1993 .

[16]  F. D'auria,et al.  Outline of the uncertainty methodology based on accuracy extrapolation , 1995 .

[17]  Djamel Lakehal,et al.  New Challenges in Computational Thermal Hydraulics , 2005 .

[18]  Francesco Saverio D'Auria,et al.  Development and use of a Code with capability of Internal Assessment of Uncertainty , 2000 .

[19]  Myong-Seop Kim,et al.  Radial Uniformity of Neutron Irradiation in Silicon Ingots for Neutron Transmutation Doping at Hanaro , 2006 .

[20]  Kostadin Ivanov,et al.  Analysis of the OECD/DOE/CEA VVER1000 CT-1 benchmark using Relap5/Parcs coupled codes , 2005 .

[21]  W. Ambrosini,et al.  Evaluation of accuracy of thermal hydraulic code calculation , 1990 .

[22]  John H. Mahaffy,et al.  On the automated assessment of nuclear reactor systems code accuracy , 2002 .

[23]  Alessandro Petruzzi,et al.  Approach and Method to Evaluate the Uncertainty in System Thermal-Hydraulics Calculations: Key Applications by CIAU Method , 2007 .

[24]  Alessandro Petruzzi,et al.  Methodology of Internal Assessment of Uncertainty and Extension to Neutron Kinetics/Thermal-Hydraulics Coupled Codes , 2005 .

[25]  Soeren Kliem,et al.  Uncertainty and sensitivity analyses of the Kozloduy pump trip test using coupled thermal–hydraulic 3D kinetics code , 2006 .