| Popis: |
We examined the (p,x), (α,x), and (n,x)reaction cross sections, for the destruction of the long-lived exotic 99Tc nuclide, which is in spent fuels of nuclear power plants and radioactive waste released from hospitals. The cross sections were calculated based on different models of nuclear level density and radiative gamma strength function. We found that there is a large uncertainty in the calculated cross sections, which is up to one order of magnitude, due to the difference in the theoretical models. The (p,n), (α,n), and (n,γ)reactions have large cross sections, which are about hundreds of millibarn. Hence, these reactions are suggested for the 99Tc transmutation. To examine the reliability of the models, the calculated cross sections were compared to evaluated data in the ENDF database. The results indicate that although all the models are consistent with the ENDF data, the Constant-temperature Fermi Gas and Kopecky–Uhl Generalized Lorentzian models are the most reliable models for the investigated reactions of 99Tc. The present study is useful for better transmutation of the radioactive waste and understanding of the dependence of the cross section on the nuclear level density and gamma strength function. |
