ENDF/B-VIIIβ4 benchmark test with iron and concrete shielding experiments using 40 and 65 MeV neutrons at QST/TIARA

The latest beta version of ENDF/B-VIII, ENDF/B-VIIIβ4 was released in February 2017 from the Cross Section Evaluation Working Group. We benchmarked the iron and concrete shielding experiments with 40 and 65 MeV neutrons at QST/TIARA by using ENDF/B-VII.1, JENDL-4.0/HE and ENDF/B-VIIIβ4 to investigate whether the ⁵⁶Fe and ¹⁶O data in ENDF/B-VII.1 were properly improved in ENDF/B-VIIIβ4 or not. The drastic overestimation in the calculated result with ENDF/B-VII.1 was resolved in that with ENDF/B-VIIIβ4 in the iron experiment with 40 MeV neutrons, because of the revision of the non-elastic scattering cross section data of ⁵⁶Fe in ENDF/B-VIIIβ4. However, the calculated result with ENDF/B-VIIIb4 significantly underestimated the measured one in the experiment with 65 MeV neutrons. The drastic overestimation in the calculated results with ENDF/B-VII.1 still appeared in those with ENDF/B-VIIIβ4 in the concrete experiments with 40 and 65 MeV neutrons, due to no improvement of ¹⁶O data particularly above 20 MeV in ENDF/B-VIIIβ4. We figured out that the effect of the ¹⁶O data replacement was very large and those of ²⁸Si and ²⁷Al data replacements were also not so small. The official release of ENDF/B-VIII should be produced based on this study.