Aspects of using a best-estimate approach for VVER safety analysis in reactivity initiated accidents
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I. Ovdiienko
Abstract
At present time, Ukraine faces the problem of small margins of acceptance criteria in connection with the implementation of a conservative approach for safety evaluations. The problem is particularly topical conducting feasibility analysis of power up-rating for Ukrainian nuclear power plants. Such situation requires the implementation of a best-estimate approach on the basis of an uncertainty analysis. For some kind of accidents, such as loss-of-coolant accident (LOCA), the best estimate approach is, more or less, developed and established. However, for reactivity initiated accident (RIA) analysis an application of best estimate method could be problematical. A regulatory document in Ukraine defines a nomenclature of neutronics calculations and so called “generic safety parameters” which should be used as boundary conditions for all VVER-1000 (V-320) reactors in RIA analysis. In this paper the ideas of uncertainty evaluations of generic safety parameters in RIA analysis in connection with the use of the 3D neutron kinetic code DYN3D and the GRS SUSA approach are presented.
Kurzfassung
Derzeit sind bei der Anwendung eines konservativen Ansatzes für Analysen von reaktivitätsinduzierten Störfällen (RIA), insbesondere bei der Untersuchung der Machbarkeit einer Leistungserhöhung in ukrainischen Kernkraftwerken, die Sicherheitsabstände zu den Akzeptanzkriterien zu klein. In einer derartigen Situation ist die Anwendung eines Best-Estimate-Ansatzes in Verbindung mit einer Unsicherheitsanalyse notwendig. Für einige Störfälle, wie z.B. Kühlmittelverluststörfälle (LOCA), ist der Best-Estimate-Ansatz mehr oder weniger entwickelt und etabliert. Hingegen kann die Anwendung von best-estimate Methoden bei der Untersuchung von reaktivitätsinduzierten Störfällen (RIA) problematisch sein. Das ukrainische Regelwerk definiert in einem Verzeichnis für reaktorphysikalische Berechnungen sogenannte „sicherheitstechnische Rahmenparametern“, die als Randbedingungen in RIA-Analysen für alle Reaktoren vom Typ WWER-1000 (V-320) anzuwenden sind. Im vorliegenden Bericht werden die Ideen für die Untersuchung von Unsicherheiten in sicherheitstechnischen Rahmenparametern bei RIA-Analysen diskutiert in Verbindung mit der Nutzung des 3D Kinetikprogramms DYN3D und der GRS SUSA Methode.
References
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© 2016, Carl Hanser Verlag, München
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Editorial
- Research on the reactor physics and reactor safety of VVER reactors – AER Symposium 2015
- Technical Contributions/Fachbeiträge
- Monte-Carlo code calculation of 3D reactor core model with usage of burnt fuel isotopic compositions, obtained by engineering codes
- Xenon instability study of large core Monte Carlo calculations
- Error detection in core loading in the condition of asymmetrical distribution of power
- New models in VERONA 7.0 system
- Methodology for determining of the weighted mean coolant temperature in the primary circuit hot legs of WWER-1000 reactor plants
- Verification of three-dimensional neutron kinetics model of TRAP-KS code regarding reactivity variations
- Aspects of using a best-estimate approach for VVER safety analysis in reactivity initiated accidents
- Qualification of coupled 3D neutron kinetic/thermal hydraulic code systems by the calculation of a VVER-440 benchmark – re-connection of an isolated loop
- Uncertainties of the KIKO3D-ATHLET calculations using the Kalinin-3 benchmark (Phase II) data
- Coupled code analysis of uncertainty and sensitivity of Kalinin-3 benchmark
- Efficient introduction of natural uranium and thorium into nuclear energy system
- Economical aspects of multiple plutonium and uranium recycling in VVER reactors
- Neutronic analysis of absorbing materials for the control rod system in reactor ALLEGRO
- Uncertainty analysis and flow measurements in an experimental mock-up of a molten salt reactor concept
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Editorial
- Research on the reactor physics and reactor safety of VVER reactors – AER Symposium 2015
- Technical Contributions/Fachbeiträge
- Monte-Carlo code calculation of 3D reactor core model with usage of burnt fuel isotopic compositions, obtained by engineering codes
- Xenon instability study of large core Monte Carlo calculations
- Error detection in core loading in the condition of asymmetrical distribution of power
- New models in VERONA 7.0 system
- Methodology for determining of the weighted mean coolant temperature in the primary circuit hot legs of WWER-1000 reactor plants
- Verification of three-dimensional neutron kinetics model of TRAP-KS code regarding reactivity variations
- Aspects of using a best-estimate approach for VVER safety analysis in reactivity initiated accidents
- Qualification of coupled 3D neutron kinetic/thermal hydraulic code systems by the calculation of a VVER-440 benchmark – re-connection of an isolated loop
- Uncertainties of the KIKO3D-ATHLET calculations using the Kalinin-3 benchmark (Phase II) data
- Coupled code analysis of uncertainty and sensitivity of Kalinin-3 benchmark
- Efficient introduction of natural uranium and thorium into nuclear energy system
- Economical aspects of multiple plutonium and uranium recycling in VVER reactors
- Neutronic analysis of absorbing materials for the control rod system in reactor ALLEGRO
- Uncertainty analysis and flow measurements in an experimental mock-up of a molten salt reactor concept
