The Spectral Distribution of Neutrons and Neutron Reaction Cross Sections in an Unreflected Uranium-235 Critical Assembly and the Fission Neutron Spectrum

LMFBR (Liquid Metal Fast Breeder Reactor) Readtion Rate and Dosimetry 3rd Quarterly Progress Report December 1971 January February 1972

“…In conclusion, and as stated elsewhere, (11,19,21) inconsistencies betvJeen integral and differential quantities continue to cast doubt on the reliability of (1) the fission spectral form, (2) evaluated activation reaction cross section data, and (3) the multiple foil method. Previous studies(l9) indicate that measurements of reaction rates and lack of solution uniqueness are unlikely sources of significant error for the multiple foil method.…”

Studying Neutron Spectra at the Centers of the Metal Cores of Fast Research Reactors

“…(5) The presence of reflectors made of depleted U (as in the BIG TEN reactor) or depleted U with Pb (as in the YAYOI) does not lead to changes in the composition of the partial spectra at the centers of the reactor cores. On the contrary, the presence of a massive copper reflector close to the small core of the TAPIRO reactor, or of a lead filter in the central channel of the BR-K1 reactor, substantially changes the above spectral composition.…”

“…The experimental data on the number of nuclear reactions at the centers of the nuclear reactor metal cores examined in this work were obtained by the authors and by researchers from other Russian and foreign scientific centers [4][5][6][7][8][9].…”

Experimental Study of the Deformation of Instantaneous Neutron Spectra from the Fission of 235U Nuclei in Fast-Reactor Core Materials

“…Table 3 presents the data on the comparison of the integral cross sections of dosimetric nuclear reactions obtained in the experiments and calculations for all of the neutron fields studied. As an example, Table 3 lists the data on the difference between these cross sections for the spectra of fission neutrons from 252 U and 252 Cf nuclei and for the GODIVA reactor (United States) [7,8,17]. …”

“…To avoid possible systemic errors in calculating the neutron spectra in the fields under study, we used experimental data (integral cross sections and nuclear reaction rates) obtained at leading domestic and foreign research centers such as the Institute of Physics and Power Engineering (IPPE) with its BR-1 reactor (which uses 239 Pu as its nuclear fuel) and the Los Alamos National Laboratory (United States) with its GODIVA reactor [6][7][8].…”