Safety requirement assessment of fuel sample test in Tehran research reactor

In the present study, neutronic and thermo-hydraulic evaluation and the feasibility study of inserting a fissile material into the Tehran research reactor core are performed. The feasibility study is carried out by calculating safety related neutronic parameters of the core, i.e., excess reactivity, shutdown margin, reactivity worth of the test fuel, safety reactivity factor and power peaking factors, during irradiation experiment using MCNPX nuclear code. In addition, in order to estimate the temperatures of fuel, clad and coolant water, a detailed three dimensional heat transfer analysis is carried out using computational fluid dynamic (CFD). The simulation is performed with two different fuel enrichments: 1.2% and 1.5%. The results indicate that the maximum fuel enrichment percentage should not be more than 1.5% to keep the clad temperature below the nucleate boiling point. It is also found that insertion of this fuel rod sample in the reactor core has not substantial effect on the safety criteria of the other plate-type fuel assemblies.