Experimental study and kinetic analysis on sodium-concrete reaction in sodium-cooled fast reactor

Kikuchi, Shin  ; Seino, Hiroshi ; Ohno, Shuji  

For countermeasure against sodium leak, structural concrete is protected by steel liner in a sodium-cooled fast reactor. However, if considering severe accidental condition such as breach of steel liner by intensive sodium leak, the reaction of concrete with liquid sodium potentially may occur. The sodium-concrete reaction (SCR) may result in significant damage of structural concrete elements, the release of hydrogen and exothermic heat. Thus it is important to understand mechanism of SCR in terms of soundness of reactor structure. However, finding on the reaction kinetics is quite limited due to the experimental difficulty. In this study, kinetics of NaO-SiO reaction as subsequent reaction was focused. Based on the measured results by DSC equipment, kinetic parameters such as activation energy and frequency factor were obtained by the laws of chemical kinetics. XRD analysis was also performed to identify the reaction products and to discuss possible overall reactions.