Comparison of properties of borosilicate glass and crystalline ceramic forms for immobilization of Savannah River Plant waste

Properties of borosilicate glass and the crystalline ceramic Synroc-D waste forms for immobilization of Savannah River Plant (SRP) defense high-level waste are compared. Waste loading, leach resistance, thermal stability, mechanical stability, and radiation stability are the properties compared. Leaching data are from comparative tests performed independently at the Savannah River Laboratory (SRL) and at the Materials Characterization Center, supplemented by data on borosilicate glass from SRL and data on Synroc-D from Lawrence Livermore National Laboratory (LLNL). Mechanical stability data are from comparative impact tests at Argonne National Laboratory. Data on other properties are primarily from tests at SRL and LLNL. The comparison shows that borosilicate glass is superior in some properties, and Synroc-D is superior in others, with neither material showing a clear advantage. Based on product properties alone, either material would be acceptable for SRP waste. Potential improvements in the quality of both waste forms are discussed.