Sensitivity analysis of fission product concentrations for light water reactor burned fuel

Chiba, Go; Okumura, Keisuke ; Oizumi, Akito*; Saito, Masaki*

In order to specify important nuclear data for accurate prediction of fission product concentrations(FPC), we extensively evaluate sensitivities of FPC to nuclear data with the depletion perturbation theory. The target fission products are twelve important ones for the burnup credit. The present study successfully specifies the important nuclear data both in a UO cell and in a MOX cell. While the obtained sensitivities are mostly similar to each other between the UO and MOX cells, large differences are observed in some cases, such as the Gd-155 concentration. It is clearly shown that such differences between the UO and MOX cells come from differences in cumulative fission yields between U-235 and Pu-239 and differences in neutron flux energy spectra.