M. Yu. Semenov

Determination of the237Np(n, 2n) reaction cross section in the core of the BN-350 reactor

Analysis of irradiated fuel (regular fuel elements and special ampule samples) makes it possible to obtain data on the neutron-physical characteristics that do not lend themselves to measurement in experiments with a low neutron flux. The authors studied samples of spent fuel from regular fuel elements and samples of /sup 236/U and /sup 237/Np irradiated in special ampules. We give the results of measurements of the ratio (sigma/sub n,2n/ + sigma/sub ..gamma..,n/)sigma/sub c/ for /sup 237/Np in different zones of the BN-350 reactor and the results of calculations performed using the neptunium group constants calculated from the data of the files ENDFB IV and ENDFB V

Determination of the cross sections for some neutron reactions with structural materials in the BN-350 reactor core

The authors experimentally and theoretically determine the differential cross sections for some neutron reactions with the target nuclei of several BN-350 reactor material constituents. The nuclei include iron 54, iron 56, nickel 58, molybdenum 92, cobalt 59, manganese 55, and uranium 235. The cross sections were determined relative to the uranium 235 fission cross section by fast neutrons. Irradiation procedures are discussed and results are tabulated. The spatial distribution of the neutron and gamma spectra was calculated using the six-group approximation and the BNAB-78 system of constants.