CALCULATIONS OF (y,n) REACTION CROSS SECTION AND GAMMA RAY INCINERATION FOR MEDIUM MASS RADIOACTIVE ISOTOPES

The total y-n reaction cross section for radioactive fission products have been evaluated in the region of energy near the giant dipole resonance, from the threshold energy up to around 30 MeV. The selected fission products lay in the range of medium mass number, namely: 87Rb, 90Sr, 93Zr, 106Ru, 123Sn, 127Te, 129I and 137Cs. These radioactive isotopes were chosen as part of the radioactive waste from 235U fission. Total cross section results were used to calculate the number of incinerated nuclei, and this method shows efficiency in reducing the radioactivity of these isotopes. The obtained results show that the incineration rate of radioactive nuclei increases with the flux of the incident y-rays, whereas the required irradiation time was found to be shortened and inversely proportional to the incident y-ray flux. These results are consistent with those given by earlier researches.