Kinetic study of liquid sodium-calcite reaction for safety assessment of sodium cooled fast reactor

Kikuchi, Shin  ; Koga, Nobuyoshi*

In a sodium-cooled fast reactor (SFR), sodium-concrete reaction (SCR) may probably occur when liquid sodium from cooling system spilled into the floor may lead to fail the steel liner as protector of the structural concretes. The structural concretes of SFR comprises siliceous concreate as main body of reactor structure and perlite concrete placed between the steel liner and the siliceous concrete serving as a protector and an insulator, respectively. Therefore, the reaction behaviour between the perlite concrete and liquid sodium in the early stage of SCR should be focused. In this study, for the first step of elucidation on SCR, thermal behaviour of sodium-calcite reaction was investigated using a differential scanning calorimetry. Comparative study for the reactions of pellet and powder of the reagent CaCO3 with sodium was performed from the viewpoints of thermal behaviour and reaction kinetics.