Development of Single Pebble Benchmark Ex. I-2A for IAEA UAM CRP With MOOSE

Ex. I-2a is Uncertainty Analysis in Modelling (UAM) of stand-alone thermal-hydraulics in steady state. It belongs to IAEA Coordinated Research Project (CRP). In this paper, the work is divided into two steps. Firstly, a single pebble model is developed based on Multiphysics Object Oriented Simulation Environment (MOOSE). The model includes two regions: homogeneous fuel region and shell region. One physical field is concerned: solid temperature field. The field is solved in a Jacobian-free Newton–Krylov (JFNK) way in the MOOSE framework. Secondly, perturbation of thermal parameters is done. In this paper, helium coolant temperature, convective heat transfer coefficient, power density and solid conductivity are the main thermal parameters which are concerned. Different kinds of perturbation of thermal parameters are conducted. Thus, variation of temperature profile across the pebble, Doppler temperature, moderator temperature and maximum temperature could be got.