Simulation of Activation Experiments in an Irradiation Stand in the Context of Nuclear Decommissioning

Monte Carlo simulations are a valuable tool to determine activated areas in nuclear power plants. This paper describes the simulation of an neutron irradiation stand containing 8 (α,n) sources and polyethylene shielding. The source spectrum of beryllium (α,n) sources is calculated using conservation of energy and momentum as well as the relevant cross-sections. Monte Carlo simulations are performed using a variety of codes with and without thermal scattering data. Simulation and experimental results are within the expected range. The thermal neutron fluence is about 2.2 x 105 cm−2 s−1. The results provide a reliable basis to simulate the activation of nuclear power plant material samples.