Calculation of core neutronic parameters in electron accelerator driven subcritical TRIGA reactor

Abstract

Investigating the dependence of reactor core neutronic parameters on the accelerator related parameters such as source multiplication coefficient (Ks), beam profile and electron beam energy (Ee), have a significant impact on the design of future ADS reactors and the cost of their construction. Using the MCNPX code, core neutronic parameters were calculated for three eigenvalues levels (ks) such as axial and radial distributions of neutron flux, effective multiplication coefficient (Keff), photoneutron yield (Yn/e), net neutron multiplication (M), energy gain (G), energy constant gain (G0), power peaking factor (Pmax/Pave), and importance of neutron source (φ*) for the tungsten target in the core of TRIGA reactor which was driven by an electron accelerator. According to the results, when Ks increases safety margin and the required accelerator current (Ie) decrease, but the parameters G and φ* increase. Also, using the parabolic spatial distribution for the electron source instead of the uniform spatial distribution, the parameters Yn/e, G and M increase. In addition, by increasing Ee from 100 to 500 MeV, Yn/e and G are improved, and Ie and accelerating power (pacc) decrease. Therefore, these results suggest that the dependence of reactor core neutronic parameters on accelerator related parameters is necessary to optimize the design cost of an ADS reactor.