Behavior Estimation Focusing on the Existing Form of Hydrogen in Sodium in Sodium-Cooled Fast Reactors

In the cooling system of sodium-cooled fast reactors, it is required to identify and rapidly detect hydrogen explosively produced by sodium-water reaction when a water leak occurs due damage heat exchanger tube in steam generator (SG), contrast low-concentration background permeating through SG tubes during normal operation. present study, we focus on difference between generated reaction, theoretically estimate behavior liquid sodium using computational chemistry methods. We find that dissolved H or NaH, rather than H2, predominant form sodium, large amounts can exist stably as fine bubbles with NaH layer their surface.