MCNP model of L-54 M nuclear research reactor: development and preliminary verification

Since shut-down, Politecnico di Milano managed L-54 M nuclear research reactor according to deferred dismantling strategy. Recently, decommissioning activities have been started with preliminary radiological characterization, even though a more extended campaign would be required. In this work, a Monte Carlo N-Particle 3D model of the reactor has been proficiently developed to estimate graphite stack activation. To verify the model accuracy, several simulated criticality data have been satisfactorily compared with experimental ones, validating this computational approach as valid support to forthcoming radiological characterization campaign.