Present status of the NET IBK computer code package for in-core fuel management and related core parameter calculations

Abstract

This paper presents and discusses the current status of the NET IBK (Nuclear Engineering Department of the Boris Kidric Institute of Nuclear Sciences) computer code package for nuclear analysis of power reactors and in-core fuel management The standard scheme for reactor fuel burnup analysis comprises the WIMS code and several 2 D (RZ or XY) and 3 D (XYZ) codes for overall reactor core calculations and criticality search They are coupled and modified to compute neutron flux, power density distribution and burnup taking into account spatial variations of temperature and xenon poisoning, as well as the reactivity changes due to xenon transients during the start-up and shut-down Presently, codes for overall reactor calculations are based on finite difference solution of group diffusion equations Efforts are being made to improve reactor cell and fuel assembly parameters calculations, and to develop advanced methods for solving diffusion equations Also, an optimization model, based on coarse zonal discretization of a reactor core is being developed for optimal fuel loading pattern search The NET IBK computer code package has been extensively used to study advanced fuel utilization schemes in different types of power reactors, as well as for solving in-core fuel management problems of the own research reactors Particular attention has been paid to experimental verification of the calculational procedures In this paper, a number of interesting results is presented and discussed 15 refs, 6 figs, 7 tabs