Neutron flux distribution in a thermal column of RP-10 using CR-39 detectors

In this work it is presented the use of CR-39 detector to determine the thermal neutron flux distribution in a thermal facility of RP-10 and other critical places of interest. The method consist of radiating the CR-39 detectors (TASTRAK, 500 mm of thickness and area 1 cm2) within an acrylic container placed to different depths inside thermal column. The irradiation time went of 9 h at power 10 MW. The chemical etching was carried out using a solution of NaOH 6.25 N to 71 deg C for 6 h. The number of damages (tracks) was counted visually with an optical microscope (Carl Zeiss to 160 increases). Finally, the obtained results were compared with those obtained ones by mean of the activation technique, showing discrepancies of 5% in all length of thermal facility. (author)