Experimental Study of Volatile FP Release with Sodium and Their Mixed Aerosol Behavior during Sodium Combustion; Iodine & Cesium Test

Nakagiri, Toshio  ; Kato, Kazunori*; Miyahara, Shinya  

Experiments were carried out to study the release behavior of iodine and cesium with sodium and their mixed aerosol behabior during sodium pool combustion. The experimental results were compared with calculated results by computer codes (SPM code and ABC-INTG code). The following results were obtained from this study.(1) The measured release rates of sodium, cesium and iodine release rate during sodium combustion increased with sodium temperature rise. The calculated release rates by the SPM code did not depend on sodium pool temperature clearly as measured values.(2) Retention factors of cesium and iodine to sodium pool during sodium combustion were larger than those in equilibrium evaporation.(3) Mass concentration of cesium and iodine in sodium aerosol were nearly constant, and it was confirmed that sodium-volatile FPs mixed aerosol can be treated as single component aerosol.(4) The generation of gaseous iodine was not confirmed in this experimental series. However, the possibility of gaseous iodine generation was indicated by thermodynamical analysis, and it was found that past test results were qualitatively explained.