An Analysis Of Calculated And Measured Fission Product Activities

Calculations and measurements of delayed beta and gamma activities and spectra following nuclear fission are presented. There is good agreement between various calculations and measurements of gamma activity and spectra of U-235 fission products. There is a degree of agreement in calculated and measured beta activity. U-235 fission product beta and gamma activities are integrated over time to determine the total number of betas and the total gamma energy emitted per fission. Analysis of various information reveals that: (1) Gamma activity and spectra following fission of U-235 by thermal neutrons coincide with that of fission of U-235 by fission spectrum neutrons. (2) Gamma activities of U-235 fission products and Pu-239 fission products are identical within limits of experimental error. (3) Initial beta and gamma activities of U-238 fission products are approximately a factor of 2 higher than for U-235 fission products.