Characterization of typical irradiation channels of CNESTEN's TRIGA MARK II reactor (Rabat, Morocco) using NAA k0-Method

The aim of this work is the use of neutron activation analysis using k0-standardization method to characterize some typical irradiation channels of the Moroccan TRIGA Mark II research reactor. The two parameters of neutron flux in the selected irradiation channels used for elemental concentration calculation, f (thermal-to-epithermal ratio) and α (deviation from the 1/E distribution), have been determined as well in the pneumatic tube (PT) as in the carousel facility (CR1) using a set of Al (99.9%), Au (0.l %), Zn (99.99%) and Zr (99.8%) monitors. Results obtained for f and α in two irradiation channels show that f parameter determined in this way is different in the carousel facility (CRl) and the PT channel. This can be explained by the fact that the CR1 channel is situated in a graphite reflector and is relatively far from the reactor core, while the PT is in the core. Parameter α in the CR1 has a positive value, as expected, indicating that the neut ron spectrum is relatively well thermalized. Parameter α in the PT has a negative value, which is very small and can not significantly influence the final result obtained by k0-method. The method in our laboratory is validated by analyzing the elemental concentrations of the IAEA Standard Reference Material (Soil-7). All calculations were performed using Kay Win Software.