低除染燃料熱伝導度の検討

Study on the Thermal Conductivity of the Low-Decontaminated Fuel

中村 雅弘  

Nakamura, Masahiro

低除染燃料の炉内における性能評価の一環として,擬低除染燃料を作製し,レーザフラッシュ法を用いて熱伝導度測定を実施した。測定結果から,Klemens-Adelesの評価手法は低除染燃料の熱伝導度を評価する手法として適当であることが分かった。評価結果として,低除染燃料の熱伝導度はUO2燃料と比較して,乾式再処理後の低除染燃料では500で約16%,1500で約7%,湿式再処理後の低除染燃料では500で約10%,1500で約4%小さい値となることが分かった。

The low-decontaminated fuel, which contains significant amount of fission products from the beginning of the irradiation, is investigated as a fuel for the advanced fuel cycle. Comparison between the measured and the estimated thermal conductivity shows Klemens-Adeles formula is appropriate to the estimation of the thermal conductivity of the low-decontaminated fuel. The estimated thermal conductivity of the low contaminated fuel is smaller than that of UO2 fuel by 16% at 500degrees, and by 7% at 1500degrees in case of the fuel originated from dry reprocessing. And they are 10% and 4% in case of the low-decontaminated fuel originated from wet reprocessing.