[en] The necessity of accounting for the correlation of experimental uncertainties when determining calculational uncertainty in criticality predictions is demonstrated in this paper. An example of constructing the correlation matrix for the experimental uncertainties of the experiments with highly enriched uranium solutions performed and evaluated at the Institute of Physics and Power Engineering, Russian Federation, is presented. A conclusion is drawn with regard to the significant influence of the correlations on the average calculation-experiment deviation and the deviation uncertainty

[en] The ABBN-93 299-group cross-section library is used as a source of neutron data for criticality calculations with the MMK-KENO Monte Carlo criticality code. Validation of criticality calculations is performed using the data presented in the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments'. This paper contains a description of a validation method based on statistical analysis of discrepancies between calculated and benchmark-model k_eff's and the results of this validation for different types of experiments. Another validation method using a well-known procedure of group cross-section adjustment based on the maximum likelihood method (generalized least-squares method) and results of the validation for water-moderated highly enriched uranium homogeneous critical systems using selected experiments of the HEU-SOL-THERM type are also presented

[en] Worldwide compilation of criticality safety benchmark experiments, evaluated due to an activity of the International Criticality Safety Benchmark Evaluation Project (ICSBEP), discovers new possibilities for validation of the ABBN-93.1 cross section library for criticality safety analysis. Results of calculations of small assemblies with metal-fuelled cores are presented in this paper. It is concluded that ABBN-93.1 predicts criticality of such systems with required accuracy

[en] Results of calculations of critical assemblies with the cores of uranium solutions for the considered series of the experiments are presented in this paper. The conclusions about acceptability of the ABBN-93.1 cross sections for the calculations of such systems are made. (author)

[en] A discrete ordinate algorithm for coupled charged/neutral particle transport calculations in 2D pencil beam problems is developed. It is based on the use of the second order of accuracy adaptive WDD (AWDD) scheme for approximation both the continuous slowing down (CSD) and streaming terms of the charged particle transport equation in z geometry, and a suitable algorithm for treatment of the extended uncollided flux from an initially monodirectional beam of charged particles with given radial distribution. The developed algorithm is implemented in the 2D transport code KASKAD-S-1.5 and is applied to the high-energy coupled proton-pion-neutron-photon transport calculations. The multigroup cross-section library SADCO-2 for nucleon-meson cascade calculations coupled with standard neutron and gamma-ray cross-section libraries below 20 MeV is used. Some numerical examples are given.(author)