当前位置: X-MOL 学术J. Nucl. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Thermal diffusivity and conductivity of thorium- uranium mixed oxides
Journal of Nuclear Materials ( IF 2.8 ) Pub Date : 2018-01-11 , DOI: 10.1016/j.jnucmat.2018.01.014
M. Saoudi , D. Staicu , J. Mouris , A. Bergeron , H. Hamilton , M. Naji , D. Freis , M. Cologna

Thorium-uranium oxide pellets with high densities were prepared at the Canadian Nuclear Laboratories (CNL) by co-milling, pressing, and sintering at 2023 K, with UO2 mass contents of 0, 1.5, 3, 8, 13, 30, 60 and 100%. At the Joint Research Centre, Karlsruhe (JRC-Karlsruhe), thorium-uranium oxide pellets were prepared using the spark plasma sintering (SPS) technique with 79 and 93 wt. % UO2. The thermal diffusivity of (Th1-xUx)O2 (0 ≤ x ≤ 1) was measured at CNL and at JRC-Karlsruhe using the laser flash technique. ThO2 and (Th,U)O2 with 1.5, 3, 8 and 13 wt. % UO2 were found to be semi-transparent to the infrared wavelength of the laser and were coated with graphite for the thermal diffusivity measurements. This semi-transparency decreased with the addition of UO2 and was lost at about 30 wt. % of UO2 in ThO2. The thermal conductivity was deduced using the measured density and literature data for the specific heat capacity. The thermal conductivity for ThO2 is significantly higher than for UO2. The thermal conductivity of (Th,U)O2 decreases rapidly with increasing UO2 content, and for UO2 contents of 60% and higher, the conductivity of the thorium-uranium oxide fuel is close to UO2. As the mass difference between the Th and U atoms is small, the thermal conductivity decrease is attributed to the phonon scattering enhanced by lattice strain due to the introduction of uranium in ThO2 lattice. The new results were compared to the data available in the literature and were evaluated using the classical phonon transport model for oxide systems.



中文翻译:

or-铀混合氧化物的热扩散率和电导率

通过在2023 K下共同研磨,压制和烧结,在加拿大核实验室(CNL)制备高密度的-铀氧化物颗粒,UO 2的质量含量为0、1.5、3、8、13、30、60和100%。在卡尔斯鲁厄(JRC-Karlsruhe)联合研究中心,使用火花等离子烧结(SPS)技术以79和93 wt。%的重量制备了-铀氧化物颗粒。%UO 2。(Th 1-x U x)O 2(0≤x≤1 )的热扩散率是使用激光闪光技术在CNL和JRC-Karlsruhe处测得的。具有1.5、3、8和13重量%的ThO 2和(Th,U)O 2。UO 2的百分比被发现对激光的红外波长是半透明的,并涂有石墨以进行热扩散率测量。随着UO 2的添加,该半透明性降低,并且在约30wt。%时丧失。UO 2在ThO 2中的百分比。使用测得的密度和比热容的文献数据推导热导率。ThO 2的导热系数明显高于UO 2的导热系数。(Th,U)O 2的热导率随UO 2含量的增加而迅速降低,并且当UO 2含量为60%或更高时,or-铀氧化物燃料的电导率接近UO2。当Th和U原子之间的质量差较小时,热导率的下降归因于由于铀在ThO 2晶格中的引入而使晶格应变增强了声子散射。将新结果与文献中提供的数据进行比较,并使用经典的声子输运模型对氧化物系统进行评估。

更新日期:2018-01-11
down
wechat
bug