recognized that considerable technical work—in particular in the area of site characterization—remained to be done.

In pursuing geological disposal, national programs in several countries have encountered a number of challenges. These include understanding the nature and rates of geological processes, predicting long-term environmental change, predicting repository and waste package performance, and predicting long-term human behavior for the purposes of risk estimation. Those national programs that have made or are in the transition from research to repository development confronted a challenge that has both technical and sociological overtones: Simply put, many members of the public do not believe that geological isolation can be proven to be a safe, long-term waste disposal solution. They doubt the ability of experts to predict future changes or to make the right decisions to protect public health and are therefore reluctant to relinquish control of the waste, even though the continued management of this waste may be a burden on future generations. These public doubts and objections typically come to the fore when a disposal program moves into the task of identifying specific repository sites. General misgivings about safety suddenly crystallize into specific opposition.

Many national programs are seeking improved methods for addressing these challenges. Some countries have begun a phased approach to repository development while others have suspended their programs. In the United States, for example, the U.S. Department of Energy is considering a plan that would provide the capability to delay for centuries, or even indefinitely, the physical closure of a repository at Yucca Mountain, leaving the final decision on closure to a future generation. In Canada, a federally appointed panel has recommended that the government postpone the search for a repository site until broad public acceptance of the geological isolation approach has been achieved. In Germany, there has been intense public opposition to moving spent fuel to an interim storage facility near Gorleben, the site of the German candidate repository, and the decision on whether to proceed with development of a repository at Gorleben has been delayed. In the United Kingdom, a House of Lords committee conducted a full-scale inquiry into the management and disposal of radioactive wastes after a government decision to cancel a proposed rock laboratory project at Sellafield. Spain has halted its siting program, and in Holland all work on specific disposal projects has been formally suspended for a hundred years.

In the midst of this general picture of forced or planned delays in repository programs, there are some counter examples. In the United States, the Waste Isolation Pilot Plant (WIPP) has gone into operation as the first deep repository designed for long-lived transuranic wastes. A community in Finland has agreed to host a repository and application has been made for a siting permit. The low-and intermediate-level waste program in Sweden is advancing.

In 1955, the U.S. Atomic Energy Commission requested that the National Academy of Sciences consider the possibilities of disposing of high-level radioactive waste in quantity within the continental limits of the United States. This request led to a conference at Princeton in 1955 and the subsequent

Front Matter (R1-R8)

Management of High-Level Waste: A Historical Overview of the Technical and Policy Challenges (1-14)

An Overview of the Workshop Agenda (15-32)

Bibliography (33-34)