Thermal neutron flux measurements in self-serve and tray rod facilities of Dhruva reactor

Dhruva is a 100 MW tank-type research reactor with natural metallic uranium as fuel and heavy water as coolant, moderator, and reflector. The reactor is utilized for production of a large variety of radioisotopes for fulfilling growing demands of various applications in industrial, agricultural, and medicinal sectors, and neutron beam research in condensed matter physics. The core consists of two on-power tray rods for radioisotope production and 15 experimental beam holes for neutron beam research. Recently, a self-serve facility has also been commissioned in one of the through tubes in the reactor for carrying out short-term irradiations. To get accurate information about thermal neutron flux, measurements have been carried out in self-serve facility and on-power tray rod K-09 of Dhruva reactor. The present report describes measurement method, analysis technique, and results. Theoretical estimations for neutron flux were also carried out and a comparison between theoretical and experimental results is made.