Development and verification of neutron and photon multi-group cross sections processing code TXMAT2.0

TXMAT2.0 is an in-house code for processing neutron and photon cross sections from the MATXS format nuclear library, which provides multi-group macroscopic cross sections for transport and diffusion calculations. In developing the program, three improvements have been made in the code. First, TXMAT2.0 adopts Fortran2003 based on object-oriented programming techniques and uses allocatable memory management techniques. Second, TXMAT2.0 is capable of processing the ultrafine group (2082 groups) library using these memory management techniques; in comparison, the officially released TRANSX2.15 has difficulty with this task. Finally, TXMAT2.0 handles correctly self-shielding corrections for light nuclides such as 12C, 16O, whereas TRANSX 2.15 experiences problems. In performing the verification and validation of TXMAT2.0, ICSBEP benchmarks for criticality verification, and OKTAVIAN and IPPE benchmarks for shielding verification were selected. Several results were compared with results obtained from TRANSX2.15 as well as with experimental data. The results show that the accuracy of TXMAT2.0 is as good as TRANSX2.15. Moreover, TXMAT2.0 provides accurate neutron and photon cross sections for multi-group transport calculations. In addition, through the verification of a selfdesigned benchmark, TXMAT2.0 processes effectively and correctly self-shielding problems of light nuclides.