Validation of actinide nuclear data based on reactivity worth experiments in a MOX-LWR spectrum

Am-241 thermal neutron capture cross section and neutron capture resonance integral from reactor activation and oscillation measurements

“…Results obtained with the ENDF/B-VII.1, ENDF/B-VIII.0 and JEFF-3.1.1 libraries confirm the long standing underestimation of the cross section for the 241 Am(n,γ) reaction. A new [8,9] 241 Am(1) -6.5(32)% -5.6(56)% 4.9(32)% 4.9(32)% OSMOSE-UOX [8,9] 241 Am(2) -5.5(22)% -6.4(24)% 6.0(22)% 6.0(22)% OSMOSE-UOX [10] 241 Am(1+2) -14.5(28)% OSMOSE-MOX [10] 241 Am(1+2) -12.6(24)% -4.2(24)% AMSTRAMGRAM [11,12] 241 Am(2) -3.6(10)% 7.7(10)% AMSTRAMGRAM [11,12] 241 Am(JRC) -1.6(12)% 7.3(12)% evaluation was adopted in JEFF-3.2 (and then in JEFF-3.3) in which the thermal capture cross section and the capture resonance integral were increased by 15% (747 barns) and 20% (1826 barns), respectively. However, the AM-STRAMGRAM trends of about +7%, obtained with the JEFF-3.2 library, confirm the results reported in Table 3 with the JEFF-3.3 library.…”