Uncertainty quantification and sensitivity studies on Thorium-fueled reactors

¹ Université de Strasbourg, CNRS, IPHC UMR 7178, 23 Rue du Loess BP28 67037 Strasbourg
² Université Paris 11, IN2P3-CNRS, IPNO, 15 rue Georges Clemenceau, 91406 Orsay, FRANCE

^* e-mail: eliot.party@etu.unistra.fr

Published online: 30 September 2020

Abstract

This paper shows how Total Monte Carlo (TMC) method and Perturbation Theory (PT) can be applied to quantify uncertainty due to nuclear data on reactor static calculations of integral parameters such as k_eff and β_eff. This work focuses on thorium fueled reactors and it aims to rank different cross sections uncertainty regarding criticality calculations. The consistency of the two methods are first studied. The cross sections set used for the TMC method is computed to build adequate correlation matrices. Those matrices are then multiplied by the sensitivity coefficients obtained thanks to the PT to obtain global uncertainties that are compared to the ones calculated by the TMC method. Results in good agreement allow us to use correlation matrix from the state of the art nuclear data library (JEFF 3-3) that provide insight of uncertainty on k_eff and β_eff for thorium fueled Pressurized Water Reactors. Finally, maximum uncertainties on cross sections are estimated to reach a target uncertainty on integral parameters. It is shown that a strong reduction of the current uncertainty is needed and consequently, new measurements and evaluations have to be performed.