Analysis of Measured Isotopic Compositions of High-Burnup BWR MOX Fuel

Feedback on neutron capture cross sections of 238Pu and 241Am from analyses of measured isotopic compositions of irradiated LWR fuels and MOX core physics experiments

“…In recent evaluations of neutron cross sections, the thermal and epithermal cross sections of these isotopes were 2 T. Yamamoto and T. Sakai Even though the isotopic compositions of those nuclides are not large, these differences in the capture cross sections may cause the considerable changes in the isotopic compositions in UO 2 and MOX fuels irradiated in LWRs and in the neutron multiplication factors (k eff 's) of MOX loaded light water cores. The purpose of this paper is to show the effect of the differences in the capture cross sections of 238 Pu on the isotopic compositions of 238 Pu in irradiated UO 2 and MOX fuels irradiated in BWR and PWR cores and that of the differences in the capture cross sections of 238 Pu and 241 Am on the by using the nuclear data libraries published before JENDL-4.0 [7][8][9][10][11][12][13][14][15][16]. The open symbols in Figure 3 show the examples of C/E-1's (calculation/measurement -1) obtained by using JENDL-3.3 as the nuclear data libraries for the continuous energy Monte Carlo burnup calculation code MVP-BURN [17] in the horizontal axis of the measured sample burnups.…”