[en] The HEEPC universal calculational complex providing adequate conditions for calculations and BFS measurements has been created. The HEEPC complex allows to analyse central reactivity worths, integral fission and capture cross-sections, multiplication factors of infinite and finite critical media measurements. Adequate conditions of calculational and experimental data are received by correct evaluation of cell structure heterogeneity, experimental samples self-shielding and adjoint flux resonance structure. 10 refs

[en] This institute has employed fast assemblies in 1983-1988 to refine the radiative cross sections for stable fission products that accumulate in fast reactors. Fifteen uranium and uranium-plutonium oxide and metal assemblies covering the entire spectral range of interest to fast reactors were used. Summarized here are measurements on the central reactivity coefficients used in testing and correcting the group constants, in particular fission-product capture cross sections. 9 refs., 1 fig., 2 tabs

[en] Test results of the known evaluations made for capture cross sections of nuclei-fission products of ¹⁰³Rh, ¹⁰⁵Pd, ¹⁰⁹Ag and ¹⁵³Eu made on the basis of analysis of experiments on the BFS, KBR and SEG-5 fast critical assemblies by measuring reactivity perturbations are given. The experiments confirm evaluations of the capture cross sections conventional for domestic files of evaluated data for the nuclides and they increase their reliability and accuracy. Corrected capture cross sections of the nuclides studied are also obtained and they agree with the newest differential measurements. The error of the cross sections corrected is approximately two times lower than the required level for the accuracy of data on fission product capture cross section

[en] Central reactivity coefficients for ^95,97,98,100Mo were measured in the series of BFS, KBR (USSR) fast critical assemblies and SEY (Germany). Reactivity coefficients of molybdenum isotopes are calculated with the use of group cross sections and resonance self-shielding factors on the basis of the JENDL-1 and-2 evaluations. Correction of capture cross sections is conducted for ^95,97Mo with account of differential experiments

[en] The paper is devoted to the evaluation of multiplication medium heterogeneous structure influence on K_∞. The results of heterogeneity correction calculations on K_∞ are cited. It is shown that validation of such corrections for the assemblies with high heterogeneity on a main fissile isotope in traditional way is doubtful. More suitable approach for such correction calculation is suggested. 7 refs.; 1 tab

[en] The present work is devoted at the study of neutron capture cross sections in Fission products by activation and reactivity methods in the critical assembly BF-45, simulation of BN-600 reactor

[en] Accuracy of calculation of main functionals, describibg neutron balance in fast multiplaying media is evaluated. Satisfactory agreement of experiment and calculation is concluded for the ratios of averaged cross-sections of ²³⁹Pu and ²³⁵U fission and reactivity coefficients of these isotopes

[en] Results of testing the methods for evaluation of criticality disturbances (central reactivity coefficients) for the KBR-9, KBR-10, KBR-11, BFS-22, BFS-33 and BFS-44 fast assemblies in experiments with weak resonance absorbers in heterogeneous media are considered. Applicability of the methods used is shown

[en] Central reactivity worths for twelve fission product nuclides (^95Mo,^97Mo,^98Mo,¹⁰⁰Mo, ¹⁰³Rh, ¹⁰⁵Pd, ¹⁴¹Pr, ^143Nd,¹⁴⁵Nd, ¹⁴⁹Sm, ¹⁵³Eu) were measured on 15 fast critical assemblies. The measured central reactivity worths normalized by ¹⁰B were compared with calculational values. Necessary corrections (on heterogeneity of media, self-shielding of media and that of a sample and others) were introduced to ensure adequate conditions for the comparison. The IPPE recommended library of fission product capture cross-sections was tested by this comparison and some corrections to these cross-sections were proposed. A satisfactory agreement of the obtained experimental data with STEK and CFRMF experiments was observed in case of similar conditions. The evaluated experimental information was used for updating BNAB group cross-section library (BNAB-90). (author)

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