Measuring the effect of WWER-400 scram and control assemblies on the fission density spatial distribution

A series of critical experiments was performed at the LR-0 reactor with a view to determining the effect of the WWER-440 type scram and control assemblies on the spatial distribution of fission density in the reactor core. A model of the assembly was used, and three reactor core variants were set up, corresponding to the cases where (i) only the fuel part, or (ii) the fuel, transition, and absorption parts, or (iii) only the absorption part is inserted into the reactor core. For each variant, the spatial distribution of fission density was determined based on measurement of the gamma activity of the irradiated fuel pins. The effect examined is characterized by axial and radial distributions and by the non-uniformness factors derived from them. The results were included in a database to serve in comparisons with calculated values. (author) 5 figs., 5 refs