The Seminar on the Research and Development for the Fast Breeder Reactor Cycle -Discussion on Future Prospect of the Research and Development with Young Researchers- -Held in Feb.7,2003-

Koi, Mamoru; Chatani, Keiji; Hasegawa, Makoto

The application of the fluoride volatility process in the reprocessing of fuel from the fast breeder reactor is regarded as one of the economical methods. Plutonium hexafluoride (PuF6), however, reacting with fluorine (F2) and plutonium dioxide (PuO2) as the raw material, is in an unstable condition and tends to remain as a solid compound in the process after decomposing into plutonium tetrafluoride (PuF4). Suitable conditions should be established for the practical use of this process. One of them is to enhance the stability of PuF6. The behaviour of plutonium fluorination and relevant chemical reactions were investigated by referring to sundry literature and by thermodynamic calculation. It was then compared with recent data from laboratory scale experiments for this paper. Results from the theoretical analysis agreed with experimental observation that PuF6 could be formed stably under a high temperature condition (approx.1000 K) with over supply of figher concentration of F2.