Preliminary estimation of long-lived activation products in the reactor structures of SMART

The structural material of an integral reactor SMART is irradiated by neutrons released during fission reactions of a reactor core. The fission process is not a major contributor to a worker's dose at the power plants because the fission process is occurring in the reactor core inside a reactor vessel. The reactor vessel is located within the reactor cavity inside the containment, and workers are not normally allowed to be around the reactor vessel during operation. The total neutron flux in the reactor vessel of SMART was calculated using the GEOSHIELD code. The radioactivity due to activation products in a flow mixing header assembly and in a reactor pressure vessel of the integral reactor was estimated using the ORIGEN2.2 code preliminarily. It was assumed that the materials have been irradiated for 60 years at full power and the irradiation was under constant neutron fluxes. The radioactivity due to activation products in the structural material is used to estimate the exposure level of radiation workers around the reactor vessel. (author)