Shielding experiments for optimization of shield materials in fast reactor using SSNTDs

Abstract

Neutron transport through single shield materials for fast reactor was experimentally studied using solid state nuclear track detectors (SSNTDs) and activation techniques. The single shield materials studied were stainless steel (SS-316), sodium and borated graphite. Neptunium and thorium foil in contact with Lexan track detectors were used to study neutron attenuation in the intermediate neutron energy region. Further, activation detectors using indium foil were also used to study the attenuation in the similar neutron energy region. It is shown in the present paper that SSNTDs can be used as a complimentary to activation detectors used to study deep penetration shielding experiments, where measurements were carried out to study neutron attenuation of the order of 10−4. The fission reaction rates of 237Np having effective threshold energy of 0.6 MeV and 232Th having threshold energy of 1.4 MeV were studied by counting the neutron induced fission track density on Lexan polycarbonate. The reaction rate from 115In(n,n′)In115m foils having effective threshold energy of 1.3 MeV was studied by activation techniques.