[1B07-11] Uncertainty Evaluation

[1B07] Uncertainty Quantification of Criticality in the KUCA-C core with HEU Fuel

*Kota Morioka¹, Cheolho Pyeon¹ (1. Kyoto Univ.)

Keywords:Kyoto University Critical Assembly, Highly-enriched uranium (HEU) fuel, Uncertainty, Criticality, Eigenvalue bias

To quantify the uncertainty of reactor physics parameters in the KUCA-C core with HEU fuel, numerical analyses of criticality and reactivity are preliminarily performed with the use of Monte Carlo calculation code (MCNP6.2 with ENDF/B-VII.1). Criticality is evaluated by the eigenvalue bias defined by the difference between the effective multiplication factors obtained by MCNP6.2 and the experiment. From the results, eigenvalue bias is found to be about 400 to 700 pcm, indicating tendency of decreasing with an increase of the H/U ratio. Furthermore, numerical reactivity by MCNP6.2 shows a relative difference about 10%, comparing with experimental one. Uncertainty of criticality induced by nuclear data could be analyzed with the use of SCALE code system.