[2K15-18] Safety in Fuel Cycle

[2K18] Study on ruthenium volatilization during evaporation and dryness of nitrate solution

Volatilization of tetroxide ruthenium during dryness and denitration of simulated high-level liquid waste

*Tetsuya Kato¹, Tsuyoshi Usami¹, Takeshi Tsukada¹ (1. CRIEPI)

Keywords:High level liquid waste, Ruthenium, Volatilization, Loss of coolant function, Mass spectrometry, Accident of evaporation to dryness

In a cooling malfunction accident of a high-level liquid waste (HLLW) tank, part of radioactive ruthenium (Ru) is potentially released to the environment as volatile RuO₄. In this study, a simulated HLLW containing Ru was heated, and the gases of RuO₄ and so on evolved during the dryness and denitration between 423 and 723 K were measured by means of the mass spectrometer.