Computational analysis of the dose rates at JSI TRIGA reactor irradiation facilities

Abstract

The JSI TRIGA Mark II, IJS research reactor is equipped with numerous irradiation positions, where samples can be irradiated by neutrons and γ-rays. Irradiation position selection is based on its properties, such as physical size and accessibility, as well as neutron and γ-ray spectra, flux and dose intensities. This paper presents an overview on the neutron and γ-ray fluxes, spectra and dose intensities calculations using Monte Carlo MCNP software and ENDF/B-VII.0 nuclear data libraries.The dose-rates are presented in terms of ambient dose equivalents, air kerma, and silicon dose equivalent. At full reactor power the neutron ambient dose equivalent ranges from 5.5×103Svh−1 to 6×106Svh−1, silicon dose equivalent from 6×102Gy/hsi to 3×105Gy/hsi, and neutron air kerma from 4.3×103Gyh−1 to 2×105Gyh−1. Ratio of fast (1MeV<E) vs. thermal neutrons (E<0.625eV) ranges from 1.5 to 8.4×10−2,γ ray ambient dose equivalent at full reactor power from 3.4×103Svh−1 to 3.6×105Svh−1 and γ air kerma range 3.1×103Gyh−1 to 2.9×105Gyh−1.