program in the near future. The concept underlying these national programs is that a nation with commercial nuclear reactors will retain its own HLW, either in the form of spent fuel or as the waste residue from reprocessing, and will dispose of this waste in its own territory. The United States and several European nations are far along in planning HLW repositories, but no country has approved a design and commenced construction, although the United States has started operation of a geological repository for long-lived transuranic intermediate-level waste (the Waste Isolation Pilot Plant, see Sidebar 4.1). The national HLW programs regularly share technical data and the results of ongoing scientific research, and many scientific experts participate in multiple national programs. International conferences are held regularly, and international organizations such as the NEA, the International Atomic Energy Agency, and the European Union have promoted consensus building on appropriate principles and technology for a HLW program.
Several factors suggest that it may be appropriate to increase the extent of international cooperation on HLW. The motivating factors and potential new initiatives are discussed in Chapter 9 .