Spark plasma sintering-reactive synthesis of SrWO4 ceramic matrices for Sr-90 immobilization

The paper studies an original way to obtain mineral-like ceramics matrices suitable for solid immobilization of a high-energy 90Sr isotope, which are safe configurations of the active zones of ionizing irradiation sources. Spark plasma sintering-reactive synthesis (SPS-RS) has been implemented for the first time to fabricate SrWO4 ceramics via “in situ” interaction of the SrO and WO3 mixture in vacuum media under uniaxial pressing. XRD, SEM, and EDX were used to identify phase composition, elemental contents and structure of the obtained ceramics. Dynamics of the oxide mixture densification were studied under the conditions of spark plasma heating in the range of 900–1200 °C with the physico-mechanical properties of the final consolidated SrWO4 matrices being determined. Presented approach provides rapid (minute-long) synthesis of dense matrices exhibiting low desalination rate of strontium (10−5–10−6 g/cm2·day) and satisfying the required standards.