Actinide Thermodynamics at Elevated Temperatures

Friese, Judah I. ; Rao, Linfeng ; Xia, Yuanxian ; Bachelor, Paula P. ; Tian, Guoxin

Pacific Northwest National Laboratory (U.S.)

关键词: Specific Heat;    Calorimetry;    Phosphates;    Actinides;    Spectrophotometry;   

DOI  :  10.2172/1025102
RP-ID  :  PNNL-16734
RP-ID  :  AC05-76RL01830
RP-ID  :  1025102

美国|英语

来源: UNT Digital Library

【 摘 要 】

The postclosure chemical environment in the proposed Yucca Mountain repository is expected to experience elevated temperatures. Predicting migration of actinides is possible if sufficient, reliable thermodynamic data on hydrolysis and complexation are available for these temperatures. Data are scarce and scattered for 25 degrees C, and nonexistent for elevated temperatures. This collaborative project between LBNL and PNNL collects thermodynamic data at elevated temperatures on actinide complexes with inorganic ligands that may be present in Yucca Mountain. The ligands include hydroxide, fluoride, sulfate, phosphate and carbonate. Thermodynamic parameters of complexation, including stability constants, enthalpy, entropy and heat capacity of complexation, are measured with a variety of techniques including solvent extraction, potentiometry, spectrophotometry and calorimetry