Thermal decomposition analysis of simulated high-level liquid waste in cold-cap
Research Laboratory for Nuclear Reactor, Tokyo Institute of Technology,
2-12-1-N1-2, Ookayama, Meguro-ku,
⁎ e-mail: email@example.com
Received in final form: 30 September 2016
Accepted: 8 November 2016
Published online: 15 December 2016
The cold cap floating on top of the molten glass pool in liquid fed joule-heated ceramic melter plays an important role for operation of the vitrification process. A series of such phenomena as evaporation, melting and thermal decomposition of HLLW (high-level liquid waste) takes place within the cold-cap. An understanding of the varied thermal decomposition behavior of various nitrates constituting HLLW is necessary to elucidate a series of phenomena occurring within the cold-cap. In this study, reaction rates of the thermal decomposition reaction of 13 kinds of nitrates, which are main constituents of simulated HLLW (sHLLW), were investigated using thermogravimetrical instrument in a range of room temperature to 1000 °C. The reaction rates of the thermal decompositions of 13 kinds of nitrates were depicted according to composition ratio (wt%) of each nitrate in sHLLW. It was found that the thermal decomposition of sHLLW could be predicted by the reaction rates and reaction temperatures of individual nitrates. The thermal decomposition of sHLLW with borosilicate glass system was also investigated. The above mentioned results will be able to provide a useful knowledge for understanding the phenomena occurring within the cold-cap.
© K. Kawai et al., published by EDP Sciences, 2016
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.