Evaluation of energy spectrum around structural materials in radiation environments

摘要

Structural materials such as stainless steel (SUS) in nuclear reactor are exposed by the environment of ionizing radiations so that their corrosion and degradation take place. These radiation effects depend strongly on the quality of radiation (energy, kind) around the materials. The metallic materials with various thickness have been examined in previous works on the radiation effects, but not with a common thickness. The different thickness would give the different radiation quality, leading to the different results of radiation effects on the materials. In this work, when radiation sources of Cs-137, Sr-90 and Y-90 were assumed to be put in the front of a plain SUS304 plate as a typical material submerged in water, energy spectra of secondary photons and electrons at the front and back sides of plate were simulated with changing the thickness of plate, and spacing between the source and plate by using a Monte Carlo calculation code of PHITS.