Numerical study on sodium-water reaction mechanism in the gas phase using counter-flow reaction region

Sogabe, Joji ; Takata, Takashi*; Yamaguchi, Akira*; Kikuchi, Shin  ; Ohshima, Hiroyuki

Sodium water reaction (SWR) is a design basis accident of a sodium-cooled fast reactor (SFR). In a steam generator (SG) of the SFR, when a heat transfer tube fails, highly pressurized water or water vapor will leak into liquid sodium resulting in a chemical reaction between sodium and water or water vapor. The mechanisms of the SWR are complicated and have not been fully elucidated. The authors have developed a numerical code and have carried out SWR experiments of a counter-flow diffusion flame (in gas phase). In this paper, the authors perform numerical simulations based on the experimental conditions to validate two chemical reaction models. In addition, sensitivity analyses are performed for various hydration numbers and water vapor flow velocities. It is founded that hydration reaction occurs somewhat in the gas-phase reaction and that influences of the water vapor flow velocity are not negligible mainly from the viewpoint of the reaction surface location.