Characteristic of the RSG-GAS core using silicide fuel

RSG-GAS has been operating for 30 years since the first criticality in 1987. In the early design, RSG-GAS used uranium oxide fuels with low enrichment. In 1996, the fuel was changed to become uranium silicide with the similar enrichment and density of 19.75 % and 2.96 gU/cm³, respectively. After that, an assessment has been conducted to change the fuel of RSG-GAS reactor with the same composition but with the increased density of 3.55 gU/cm³. Right now, the assessment also is being conducted for uranium molybdenum fuel with density of 3.55 gU/cm³. This paper will discuss characteristics of the RSG-GAS core using different fuel types but with the same density and enrichment. The characteristics to the RSG-GAS is obtained from calculations and available experiment results. Results of assessment show that the characteristics of RSG-GAS core with 2.96 gU/cm³ of density for uranium oxide and 3.55 gU/cm³ of density for uranium silicide and molybdenum have relatively similar kinetics parameters but different neutronic parameters. Therefore, it is concluded that characteristics of RSG-GAS core depend on its fuel types. (author)