Release rate of non-volatile fission products during sodium-concrete reaction

Miyahara, Shinya  ; Haga, Kazuo; Himeno, Yoshiaki

A series of tests was conducted to studythe mechanical release of non-volatile fission products during sodium-concrete reaction,in which hydrodynamic break-up by the hydrogen bubble bursting is predominant at the sodium pool surface. In thetests,non-radioactive materials,namely strontium oxide,europium oxide,and ruthenium particles whose sizes ranged from some microns to several tens of microns,were used as simulated non-volatile fission products. The following results were obtained from the present study: (1) The sodium aerosol release rate during the sodium-concrete reaction was larger than that of natural evaporation. The difference,however,became smaller with the increase in the sodium temperature; nearly 10 times at 400 C and 3 times at 700 C. (2) Retention factors of these non-volatile materials in sodium pool increased inthe range of 0.5 to the fourth power of10 with the increase in the sodium temperature from 400 C to 700 C