An Analysis of the Doppler Effect of Structural Materials

This paper describes an analysis of the Doppler effect of structural materials, having a possibility of the importance in fast reactor safety. The shielding factors of the effective capture cross sections are prepared for chromium, iron, and nickel based on the nuclear data of ENDF/B-II. Using these shielding factors, the Doppler experiments for stainless steel and natural iron performed in the JAERI-FCA cores are analyzed by a simple perturbation method.The computed results are in fairly good agreement with the experiment although they are a little lower. It is suggested that the lower values might be attributed to the missing level of the sharp p- and d-wave resonances above 30 keV or to neglecting the contributions from the unresolved resonances.