Research and development activities carried out at Sandia National Laboratories from 2009-2012
have built the technical baseline for performance of a deep borehole for disposal of nuclear
waste. Early work established the coupled thermo-hydrological-mechanical-chemical forces
likely to control radionuclide movement from a deep borehole. This report emphasizes more
recent borehole science and engineering activities including: 1. Establishing a reference borehole
design; 2. Developing the design for borehole seals; and 3. Identifying the nature and extent of
site characterization needed for deep borehole siting.