Erprobung reaktorphysikalischer Rechenverfahren am kritischen Experiment zum HTR (KAHTER) im Hinblick auf die Güte der Berechenbarkeit des Einflusses des oberen Hohlraumes

摘要

This report deals with the checking of computations of various experiments at the critical facility for the high temperature pebble bed reactor (KAHTER). In particular computational methods are tested which are to be used for treating the cavity and for calculating the efficiency of absorber rods in pebble bed reactors with OTTO-Ioading. In addition, with regard to a top reflectorinstrumentation, the effects of disturbances in the upper core region on the shape of neutron flux in the top reflector are studied. In the diffusion calculations for determination of critical masses and neutron flux distributions of various core configurations, standard diffusion programs are used such as the 2D-code DIFF-2D and the 2- and 3-dimensional program CITATION, as weIl as recently developed diffusion codes. To the latter belong the program HRMC/DIFF-H, which treats the cavity by means of transport theory, and the finite element code DIFGEN. For comparison, Monte Carlo calculations are performed with the MORSE-K code.