A technique for mathematical modeling of the container's protective characteristics for the spent fast neutron sources, first of all 238,239Pu-Be, long-term storing was developed. It provides a systematic approach, in particular the consideration of all the physical processes that may affect the radiation safety level. It has been shown that in addition to the neutron radiation should be considered high-energy gamma rays from the decay of high excited 12С levels, formed as directly in the 9Be(α, n)12*C reaction, so as in the process of interaction of neutrons with 12C nuclei of the hydrogen-containing protective materials of the container. Some contribution to the dose is made by other secondary gamma rays resulting from neutron interaction with the container shielding and structural materials so as the gammaradiation due to the radioactive decay of the plutonium isotopes and 241Am, which accumulates at the 241Pu impurities decay during long-term storing.
Keywords: mathematical simulation, neutron sources, storage container.
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