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Title: Uranium (VI) solubility in carbonate-free ERDA-6 brine

Journal Article ·

When present, uranium is usually an element of importance in a nuclear waste repository. In the Waste Isolation Pilot Plant (WIPP), uranium is the most prevalent actinide component by mass, with about 647 metric tons to be placed in the repository. Therefore, the chemistry of uranium, and especially its solubility in the WIPP conditions, needs to be well determined. Long-term experiments were performed to measure the solubility of uranium (VI) in carbonate-free ERDA-6 brine, a simulated WIPP brine, at pC{sub H+} values between 8 and 12.5. These data, obtained from the over-saturation approach, were the first repository-relevant data for the VI actinide oxidation state. The solubility trends observed pointed towards low uranium solubility in WIPP brines and a lack of amphotericity. At the expected pC{sub H+} in the WIPP ({approx} 9.5), measured uranium solubility approached 10{sup -7} M. The objective of these experiments was to establish a baseline solubility to further investigate the effects of carbonate complexation on uranium solubility in WIPP brines.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC52-06NA25396
OSTI ID:
1024353
Report Number(s):
LA-UR-10-01817; LA-UR-10-1817; TRN: US1104721
Country of Publication:
United States
Language:
English

References (4)

Solubility of Nd3+ and UO22+ in WIPP brine as oxidation-state invariant analogs for plutonium journal October 2007
Solid-liquid Phase Equilibria of U(VI) in NaCl Solutions journal January 1998
Solubility and hydrolysis of tetravalent actinides journal January 2001
Dependence of Actinide Solubility and Speciation on Carbonate Concentration and Ionic Strength in Groundwater journal May 1992