Improvement of the atomic number density calculation program AND for nuclear fuel materials

Tokubo, Keisuke*; Kameyama, Takanori*; Suyama, Kenya

For conducting the criticality calculation, it is necessary to set the nuclide density data. To evaluate them with high reliability needs large effort than expected because many parameters are required. A computer program AND was developed for the evaluation of nuclide density data for the criticality safety evaluation. It has been pointed out that the AND program used old data and it could not evaluate the nuclide density data of U-234 and U-236. The revise of AND was carried out to overcome these problems. We conducted the analyses of the criticality experiments of STACY and TCA by adopting the continuous energy Monte Carlo code MVP2.0 and revised AND. And the improved performance of the revised AND was confirmed.