Disassembly of old radium sources and conversion of radium sulfate into radium carbonate for subsequent dissolution in acid

In this work details of safe radium source disassembly which were previously used in brachytherapy are described and different methods for conversion of RaSO₄ into aqueous solution are reviewed. The method of choice included three cycles of RaSO₄ heating in 1.5 M Na₂CO₃ up to 85 deg C, cooling and subsequent removal of supernatant. X-ray diffraction study showed that the method allows the synthesis of, presumably, amorphous RaCO₃, which can be dissolved in mineral acid. Gamma spectrometric measurements showed that most of the initial RaSO₄ was converted into solution and that 7 ± 1 % of the initial ²¹⁰Pb was co-precipitated with RaCO₃. (author)