Improved Modelling Of The Neutron Field At The Portuguese Research Reactor And Its Experimental Validation

The neutron field in the core and reflector regions of the Portuguese Research Reactor (R-PI) was simulated with the Monte Carlo code MCNP-4C, using criticality and fixed-source calculations. A comparison of the results obtained with MCNP and the deterministic codes WIMSD-5 and CITATION was performed, showing consistence between them for the effective multiplication constant and the neutron fluxes. The calculations and measurements agree within 15%. Therefore the model can be used to predict the neutron field in the region studied and in other locations and irradiation facilities of the RPI.