Integral 14 MeV-neutron experiments with the samples of multiplying materials. Report of the IAEA research contract no. 8996 (15 December 1995 to 14 December 1996)

摘要

The work presents the description and comparison with calculations of the integral 14-MeV neutron experiments for leakage neutron spectra, total neutron leakages from U, Th, Be, Pb and Bi spherical samples, and for reaction rates in U and Th samples, carried out in Kurchatov Institute of Atomic Energy (KIAE), RF. A detailed description of the used measurement methods, experimental samples of multiplying materials and experimental results are given. The calculations were done by the BLANK code with the neutron data prepared from ENDL-75 and EDNF/B-IV libraries and by MCNP/4A code with FENDL-1 data. It was shown that the calculation with ENDF/B-IV data describes the shape of the neutron spectrum better than ENDL-75 for all considered materials. The total neutron multiplication for the U sample is reproduced more accurately by the calculation with ENDL-75 data, and for Th, and Pb assemblies, by the calculation with ENDF/B-IV data. The calculation with ENDF/B-IV data well reproduces the neutron leakage from lead samples while the calculation with ENDL-75 data slightly underestimates the neutron multiplication on lead. The calculation with ENDF/B-IV data describes the neutron multiplication for beryllium sufficiently well. The calculated total neutron leakage from Be samples with ENDL-75 data noticeably exceeds the experimental one. The calculations with FENDL-1 data perfectly (within experimental error) predict total multiplication in lead and beryllium spheres. For both bismuth spheres there is underprediction of total multiplication in calculations with FENDL-1 (approx) 8%. The calculations with FENDL-1 data in a whole predict neuron spectra for beryllium better than with ENDF/B-IV data but still there is overestimation of neutron spectra in the energy range of 0.7-3 MeV. (author). 11 refs, 3 figs, 12 tabs. (Atomindex citation 28:024275)