Uncertainty Propagation Analysis for Yonggwang Nuclear Unit 4 by McCARD/MASTER Core Analysis System

摘要

In reactor design and safety analysis, it is very important to estimate uncertainties of design parameters for evaluating the feasibility of nuclear design results of new nuclear systems as well as improving the existing nuclear cross section data and their covariance. The Monte Carlo (MC) method augmented by B_1 spectrum to generate few group diffusion theory constants (FGCs) is presented in order to take the ability of MC method to use continuous energy nuclear energy and detailed geometric information. In the MC FGCs generation, it is unavoidable to carry uncertainties of FGCs due to uncertainties of input data or statistical uncertainties. Recently, we introduce a new formulation to estimate uncertainties of FGCs by the MC method and implement into the Seoul National University MC Code McCARD. The purpose of this paper is to assess uncertainties of nuclear design parameters by uncertainty propagation analyses in McCARD/MASTER calculations for Yonggwang Nuclear Unit 4. In this two-step core neutronics analysis, McCARD is used as a FGCs generation code and MASTER as a deterministic whole core analysis code.