Verification of the evaluated fission product yields data from the neutron induced fission of 235U, 238U and 239Pu based on the delayed neutron characteristics

• We calculate macroscopic characteristics of delayed neutrons by summation method.
• We analyzed conformity of obtained results to the appropriate recommended values.
• Modeling of the time dependence of delayed neutron activity was done.
• The sensitivity of macroscopic parameters to microscopic data was studied.
• The most consistent microscopic data sets was chosen.

In the present work, the macroscopic characteristics of delayed neutrons have been calculated for the thermal and fast neutron induced fission of 235U, 238U and 239Pu by the summation method. The cumulative yields CY of 368 fission products from the latest version of JEFF, ENDF/B, JENDL, ROSFOND libraries, and Wahl data were used as the basic input data. The emission probabilities of delayed neutrons Pn and the half-lives of their precursors T1/2 were represented by four data sets obtained on the basis of the systematics and the evaluated experimental data. As a result for each database of the cumulative yields of fission products four values of the absolute total delayed neutrons yields νd and four values of the average half-life of delayed neutron precursors  were obtained. For each combination of data sets “CY – (Pn,T1/2)” a model curve of delayed neutron activity was calculated for the 235U(nth,f) reaction. The analysis of the results based on the comparison of the obtained delayed neutron macroscopic parameters νd and with the appropriate evaluated data allowed to study the sensitivity of the macroscopic delayed neutron parameters (νd, T1/2) to the microscopic delayed neutron data sets (Pn,T1/2) for each of the considered fission reactions. In addition, it can be used to choose the fission product database that is consistent with the most accurate aggregate delayed neutron data.