The concept of deep borehole disposal (DBD) for high-level nuclear wastes has been around for about 40 years. Now, the Department of Energy (DOE) in the United States (U.S.) is re-examining this concept through recent studies at Sandia National Laboratory and a field test. With DBD, nuclear waste will be emplaced in boreholes at depths of 3 to 5 km in crystalline basement rocks. Thinking is that these settings will provide nearly intact rock and fluid density stratification, which together should act as a robust geologic barrier, requiring only minimal performance from the engineered components. The Nuclear Waste Technical Review Board (NWTRB) has raised concerns that the deep subsurface is more complicated, leading to science, engineering, and safety issues. However, given time and resources, DBD will evolve substantially in the ability to drill deep holes and make measurements there. A leap forward in technology for drilling could lead to other exciting geological applications. Possible innovations might include deep robotic mining, deep energy production, or crustal sequestration of CO2, and new ideas for nuclear waste disposal. Novel technologies could be explored by Korean geologists through simple proof-of-concept experiments and technology demonstrations.

1. Introduction
 2. The Case for DBD
  2.1 Benefits of granite and other crystalline rocks
  2.2 Natural barrier system
  2.3 Siting criteria and site investigation
  2.4 Drilling, casing, and seals
  2.5 Field-testing the drilling and measurementtechnologies
 3. Issues Bearing on the Efficacy of DBD
  3.1 Is there a logical rationale for DBD?
  3.2 Technical concerns about the geologic barriers
  3.3 Technical concerns about the engineeredbarriers and emplacement methods
  3.4 Issues in site investigation
 4. Concluding Comments
 REFERENCES

• Byung-Gon Chae(Korea Institute of Geoscience and Mineral Resources) Corresponding Author
• Yongje Kim(Korea Institute of Geoscience and Mineral Resources)
• Franklin W. Schwartz(The Ohio State University)