Thorium core analysis using experimental and calculated data

Concerning about the accuracy of Th232 cross section library and other core characteristics, the critical experiment of thorium core carried out at KUCA facility of Kyoto University Research Reactor Institute have been analyzed. The core was composed of pure thorium plates and 93% enriched uranium plates, solid polyethylene moderator with H/U235=210 and Th232/U235=15.2. In the experiment, the criticality, control rod worth and Th sample reactivity worth were obtained. The MVP calculations have been done using JENDL-4.0 library. By comparing with the experimental data, the calculation overestimates the effective multiplication factor about 0.99%. The core characteristics were analyzed to confirm that the core was safely operated. The Th sample reactivity worth was measured and found to be different with the calculation results about 14%. (author)