Actinides in intermediate-level liquid waste : removal by oxalic acid precipitation followed by cement incorporation and characterization of the final product
The purpose of this study was to investigate the conditions for the provision of an alpha-free waste form (non-TRU waste with less than 100 nCi/g, or less than 3700 Bq/g) from intermediate-level liquid waste (ILLW). The alpha-emitting actinide elements were removed by precipitation with oxalic acid, followed by incorporation of the resulting filtrate in a solid cement matrix. The parameters studied for optimisation of the precipitation process were type and amount of carrier, pH, time of digestion of the precipitate and temperature at precipitation. Simulated ILLW was used to which plutonium and americium had been added, as well as genuine ILLW from reprocessing. The subsequent solidification of the filtrate in cement was studied with emphasis on the behaviour of oxalate ions in the characterisation of the product. The mechanical and chemical properties of the final cement product were measured. It was concluded that the provision of an alpha-free waste product from ILLW is feasible, with careful selection of the conditions for the oxalate precipitation and for the subsequent solidification in cement.
Bibliographic Reference: EUR 13250 EN (1991) 60 pp., FS, ECU 6.25
ISBN: ISBN 92-826-2234-7
Record Number: 199110243 / Last updated on: 1994-12-02
Original language: en
Available languages: en