Strontium in phosphate-modified calcium aluminate cement

Cements have been used to encapsulate low and intermediate level radioactive wastes. Here, phosphate-modified calcium aluminate (CAP) cement is explored as an encapsulant for strontium radioanuclide-containing wastes. Electron microscopy indicates strontium chloride, used in place of strontium radionuclides, increases porosity in CAP possibly due to increased viscosity of CAP cement during mixing. X-ray diffraction analysis detects formation of halite phase suggesting strontium chloride reacts with cement to form sodium chloride not usually detected in CAP systems as well as formation of an amorphous phase in CAP cement when thermally treated at 90°C.