Effects of fuel type on the safety characteristics of a sodium-cooled fast reactor: Part I: Background, modeling tools and pre-transient calculations

The objective of this investigation is to examine the impact of the fuel type on the inherent safety characteristics of Liquid Metal Fast Reactors (LMFRs). To perform this study, the responses to various transient conditions are examined for metallic, oxide and nitride cores of a baseline LMFR. GE-Hitachi’s Super Power Reactor Innovative Small Module (S-PRISM) was chosen as the baseline LMFR. In this paper the background on S-PRISM’s metal and oxide cores are described and the redesign of a new nitride fueled S-PRISM core is introduced. Reactivity feedback and power profile data necessary for transient simulations with RELAP5-3D/ATHENA code are also presented and discussed. Part II of this paper will present the results of accident simulations and a comparison between the metal, oxide and nitride cores based on their performance during the selected accident scenarios.

► Multiple transients were simulated with RELAP5-3D for a sodium cooled fast reactor. ► Transients were simulated for metal, oxide and nitride fueled cores. ► The metal core displayed the smallest margin to fuel melting. ► The oxide and nitride cores had similar inherent safety characteristics. ► Part II includes the results of the transient calculations.