Radial reflector discontinuity factors iteration scheme at VR-1

The macroscopic data preparation process is the essential part of the safe operation nuclear power station and despite the increasing calculation power this method stays essential in the near future. The data preparation process and mainly the assembly discontinuity factors (ADF) calculation are analysed in the paper. Developed models are connected with the C7 core of the VR-1 research reactor, which is operated by the Czech Technical University in Prague. The fuel models as well as the connection of the fuel and the reflector models are analysed. The multiplication factor and the neutron flux distribution are compared. The fuel ADF usage showed better prediction of the multiplication factor and also the neutron flux distribution. The new external iteration reflector ADF calculation method is developed, implemented and tested in the paper. The most realistic model of C7 core was used as a test case. The best results of the multiplication factor as well as the neutron flux distribution were obtained with the external iteration process ADF calculation. The multiplication factor was calculated with only 452 pcm discrepancy, more than 6600 pcm better result than without ADF and more than 3400 pcm better result than with reflector ADF calculated via SCALE Newt.