Stability Evaluation for Cement Package Containing Radioactive Waste

In order to provide stable cement packages, ettringite formation, a major cause of cement deterioration, was studied theoretically and experimentally. A computer program was developed to calculate the chemical equilibrium compositions of a complex cement system. Higher curing temperature and the addition of NaOH were identified as effective methods to avoid ettringite formation. These finding were confirmed by measuring the amount of ettringite in solidified cement by an X-ray diffraction method.