Abstracts and Available Papers Presented at the
1995 International RERTR Meeting

PROCESSING OF LEU TARGETS FOR 99Mo PRODUCTION--
DISSOLUTION OF METAL FOILS BY NITRIC-ACID/SULFURIC-ACID MIXTURES*

B. Srinivasan, R. A. Leonard, S. Aase, and G. F. Vandegrift
Argonne National Laboratory
Argonne, Illinois U.S.A.

and

Moeridun, A. A. Rauf, H. Lubis, A. Hardi, S. Amini, and Y. Nampira
Indonesian National Atomic Energy Agency
Serpong, Indonesia

Presented at the1995 International Meeting on
Reduced Enrichment for Research and Test Reactors
September 18-21, 1995
Paris, France

*Work supported by the US Department of Energy
Office of Nonproliferation and National Security
under Contract No. W-31-109-38-ENG.

ABSTRACT

The first step in processing low-enriched uranium (LEU) targets for production of Mo-99 is to dissolve the neutron-irradiated uranium foil coming from the reactor. Appropriate conditions for dissolving the foils were determined by measuring the dissolution rates for uranium foil over a wide range of temperatures and acid concentrations. On the basis of these dissolution rates, the process chemistry, and a model that integrates dissolution rates as a function of temperature and composition, a closed stainless-steel dissolver was designed, built, and tested for dissolving up to 18 g of uranium foil. The results were quite successful, with the uranium foil being dissolved within one hour as desired. To do this, the dissolver temperature must be in the range from 97 to 102 degC, and the dissolver solution (cocktail) must have a composition of 3M nitric acid and 2M sulfuric acid. The final dissolver solution is subsequently processed to separate Mo-99 from uranium, fission products, and other elements.

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