Assembly for the HTGR physics study

The GROG critical assembly designed for studying high-temperature gas-cooled reactor (HTGR) physics and in the first place, for investigating the neutron-physical characteristics of the VS-400 fuel elements is described. The GROG critical assembly represents a set of graphite blocks forming cubic laying with 450 cm side. Placing cylindrical elements with different compositions into the graphite laying channels provides various geometrical and physical parameters of the reactor core and reflector. After removing a part of the graphite blocks they can be replaced with the fragments of a reactor core under investigation. The assembly structure permits to place the monitors of the measurement system in any given order. On the basis of the calculated and experimental data analysis it is concluded that energy release field and spectral characteristics of even the such highly heter geneous system as HTGR with once-througo then-out spherical fuel elements are simulated well