Monte Carlo calculation of the core of the heavy water zero power reactor (HWZPR) using MCNP4c

The MCNP4c code, based on the probabilistic approach, was used to simulate 3D configuration of the core of the heavy water zero power reactor (HWZPR). In present work, first, all of the constituents of the core such as fuel pellets, fuel element, moderator (D2O) and annular graphite reflector were modeled using MCNP4c code. Then calculations of axial and radial neutron fluxes were performed in three energy groups such as thermal (0–0.625 eV), epithermal (0.625–550 eV), and fast (0.550–20 MeV). The cadmium ratio was calculated as well and the neutron flux parameters such as extrapolated height (He), extrapolated radius (Re) and physical center of the core (z0) were computed using cadmium ratio. Comparison of the neutron flux parameters with the experimental data showed that the MCNP4c model of the HWZPR was validated.