Development of sodium removal Technology; Molten NaK reaction basic test

Hirakawa, Yasushi ; not registered; not registered; not registered

To establish sodium removal technology is essential from the viewpoints of low radiation of works and low environmental effect at the time of maintenance, repair and decommissioning of LMFBRs. In this study, as a start of sodium removal basic test, we carried out the experiment by sodium removal basic reaction test apparatus. Molten sodium potassium alloy (NaK) as a simulated molten sodium and solid sodium were used to grasp the reaction speed of gas containing moisture and NaK or sodium. Followings are the major results: (1)Under low temperature and humidity nitrogen gas condition, molten NaK reaction rate was about twice as high as solid sodium. This result suggests the possibility of effect of sodium phase (molten or solid) to reaction rate. (2)Under relatively high temperature and humidity nitrogen gas condition, the reaction rate of molten NaK and moist nitrogen gas was about 3 times as high as low temperature and humidity nitrogen gas condition. Gas condition affects the reaction rate largely. (3)NaK and moist carbon dioxide gas could react only the surface of the NaK and the reaction could not progress to the inside of NaK. This result shows the bulk NaK could not be converted to NaK-carbonate.