Dielectric Properties of Uranium and Plutonium Nitrate Solution and the Oxide Compounds Formed in the De-nitratiin Process by the Microwave Heating Method

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加藤 良幸 ; 栗田 勉 ; 安部 智之

Kato, Yoshiyuki; Kurita, Tsutomu; Abe, Tomoyuki

マイクロ波加熱法では、硝酸ウラニルと硝酸プルトニウムとの混合溶液(硝酸U/Pu溶液)は4つのステップでMOX粉末に混合転換される。硝酸U/Pu溶液と脱硝されたMOX粉末の誘電特性を測定した。反射法ではU/Pu硝酸塩溶液とUO粉を使用した。摂動法は50%PuO・UO、-UO、-UO、およびUO粉を使用した。測定した誘電損失生成物(・tan)は、硝酸の濃度に強く影響されたが、ウランとプルトニウムイオンの動きへの依存がほとんどなかった。この現象はマクスウェル-ワグナー効果により説明した。

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 (PuF), however, reacting with fluorine (F2) and plutonium dioxide (PuO) 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 (PuF). Suitable conditions should be established for the practical use of this process. One of them is to enhance the stability of PuF. 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 PuF could be formed stably under a high temperature condition (approx.1000 K) with over supply of figher concentration of F2.