Gamma-ray spectrum data library of fission product nuclides and its assessment

A gamma-ray spectrum data library of fission product nuclides was prepared on the same basis as the JNDC library which is used for the decay heat prediction. The gamma-ray spectrum data were compiled with both measured and theoretically estimated spectra. For nuclides with no or insufficient gamma-ray transition data, the estimated spectra were applied to compensate the defect of the measured data. By introducing the estimated spectra, it becomes possible to calculate the gamma-ray spectra which are consistent with integral decay heat predictions by the JNDC library. By using the spectrum data library, calculations of gamma-ray spectra from aggregate fission product nuclides were carried out. The calculated spectra were compared with the measured ones performed at Oak Ridge National Laboratory and at the University of Tokyo. The spectrum calculations showed reasonable agreement with the measured data for a wide range of cooling time. (author) 18 refs., 11 tabs., 245 figs