Monitoring of Neutrons Field of the WWR-SM Reactor at Reception of Phosphorus-33

In the paper results of monitoring of thermal neutrons field in vertical irradiation channels of the WWR-SM nuclear research reactor of INP AS, Tashkent, Uzbekistan has been studied with purpose of determination of mode of irradiation target sulfur-33 (S-33) and increase specific activity of phosphorus-33 (Р-33). It is shown that reception P-33 with specific activity (120-140 mCi/g) is necessary to spend irradiation targets of S-33 elemental enrichment in vertical channels of the WWR-SM reactor in the following mode: irradiation place is distance of 35-50 cm below from top point of the vertical channel, nominal power of reactor=10MW, reactor thermal neutrons stream density ≥0.7⋅1014 neutrons/cm2.sec and irradiation time=320÷620 hours. Opportunity of application of S-33 as the monitor for reception of P-33 without the carrier was established. In fist time for express definition of specific activity of radionuclide P-33 in irradiation target S-33 the monitor S-33 was used