Gas generation during waste treatment of acidic solutions from the dissolution of irradiated LEU targets for 99Mo production
- Argonne National Lab. (ANL), Argonne, IL (United States)
The goal of the Reduced Enrichment for Research and Test Reactors Program is to limit the use of high-enriched uranium (HEU) in research and test reactors by substituting low-enriched uranium (LEU) wherever possible. The work reported here documents our work to develop the calcining technologies and processes that will be needed for 99Mo production using LEU foil targets and the Modified Cintichem Process. The primary concern with the conversion to LEU from HEU targets is that it would result in a five- to six-fold increase in the total uranium. This increase results in more liquid waste from the process. We have been working to minimize the increase in liquid waste and to minimize the impact of any change in liquid waste. Direct calcination of uranium-rich nitric acid solutions generates NO2 gas and UO3 solid. We have proposed two processes for treating the liquid waste from a Modified Cintichem Process with a LEU foil. One is an optimized direct calcination process that is similar to the process currently in use. The other is a uranyl oxalate precipitation process. The specific goal of the work reported here was to characterize and compare the chemical reactions that occur during these two processes. In particular, the amounts and compositions of the gaseous and solid products were of interest. A series of experiments was carried out to show the effects of temperature and the redox potential of the reaction atmosphere. The primary products of the direct calcination process were mixtures of U3O8 and UO3 solids and NO2 gas. The primary products of the oxalate precipitation process were mixtures of U3O8 and UO2 solid and CO2 gas. Higher temperature and a reducing atmosphere tended to favor quadrivalent over hexavalent uranium in the solid product. These data will help producers to decide between the two processes. In addition, the data can be used to design appropriate off-gas systems for pilot and production facilities.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1343093
- Report Number(s):
- ANL/NE-16/51; 133227; TRN: US1701920
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
HIGHLY ENRICHED URANIUM
LIQUID WASTES
MOLYBDENUM 99
URANIUM OXIDES U3O8
URANIUM TRIOXIDE
WASTE PROCESSING
RESEARCH AND TEST REACTORS
URANIUM DIOXIDE
Calcination
uranyl nitrate solution