Some uncertainty results obtained by the statistical version of the KARATE code system
26th Symposium of AER on VVER Reactor Physics and Reactor Safety (2016, Helsinki, Finland)
Advances in spectral and core calculation methods
Abstract
SOME UNCERTAINTY RESULTS OBTAINED BY THE STATISTICAL VERSION OF THE KARATE CODE SYSTEMI. Panka, Gy. Hegyi, Cs. Maráczy, E. Temesvári Centre for Energy Research, Hungarian Academy of Sciences Reactor Analysis DepartmentH-1525 Budapest 114, P.O. Box 49, Hungary istvan.panka@energia.mta.huABSTRACTThe survey of the uncertainties has been going on for several years in the frame of the Uncertainty Analysis in Best-Estimate Modeling (UAM) LWR benchmark organized by the OECD NEA. The goal of this benchmark is to determine the uncertainties of the coupled reactor physics/thermal hydraulics LWR calculations at all stages. Having experiences in this field, it was decided to elaborate the so called statistical version of the KARATE code system.In the first part of the paper, the main features of the elaborated new code system are discussed. The applied statistical method is based on Monte-Carlo sampling of the considered input data taking into account mainly the covariance matrices of the XSs and/or the technological uncertainties. Additionally, the sampled input uncertainties are propagated through the full calculation chain.In the second part of the paper, some uncertainty results – obtained by the statistical version of the KARATE code system at nodal level – are discussed for an equilibrium cycle related to a VVER-440 type reactor. This means also that the burnup dependence of the considered output uncertainties – in the term of empirical standard deviations and correlations of some safety related parameters (e.g. effective multiplication factor, boron concentration, assembly-wise radial power and burnup distribution) – are discussed, as well. 26th Symposium of AER on VVER Reactor Physics and Reactor Safety 3 10 – 14 October 2016, Helsinki, Finland