Correlation of Radiation Damage to Steel with Neutron Spectrum

Expressions are developed for the rate of production of atomic displacements in iron by neutron spectra found in reactors. Factors considered include anisotropic, elastic high-energy neutron scattering, inelastic high-energy neutron scattering, thermal-neutron capture-gamma recoil-induced displacements, and energy loss by electronic excitation. An evaluation of calculated atomic displacement density as a measure of radiation damage to steel was made by determining if this approach could rationalize the differences in damage rate produced by different reactor spectra. It was found that available data on radiation-induced property changes could be satisfactorily normalized to a common basis by expressing exposure as displacement density when all the above-mentioned factors are given consideration.