Uncertainty analysis of a typical research reactor performance for radioisotope production

Abstract

The accurate neutron flux in the different regions of irradiation positions is very important parameter in any research reactor performance with highly effects on uncertainty of produced activities. The produced activities in a research reactor core is highly dependent on 3 main groups of activity measurement, reactor and sample. The significance of these parameters is comprehensively investigated and determined numerically for a Tehran Research Reactor (TRR) as a typical research reactor. This is done using precise MCNPX 2.6.0 simulations, several experiments during reactor operation, and measurements in laboratory. The sample’s location uncertainty is one of the main parameters in the neutron flux uncertainty. Further, shadowing of samples and control rods, samples density, self-shielding, and also power measurement mechanism could be noticeable and give rise to distinctive uncertainty in the final results. It is determined that all the considered parameters could lead up to 17.8% uncertainty in the final results at the TRR which is remarkable.