Terry A. Vaeth
NTS Development Corporation

Stephen A. Mellington
DOE/NV

Robert J. Eastmond
IT Corporation

Since the first atmospheric United States nuclear weapons test on July 16, 1945, there have been more than 2,000 nuclear tests conducted worldwide. Testing has been related to weapons development, weapons safety and potential peaceful uses. The U.S. has conducted about half of those tests while other countries, primarily Russia (the former Soviet Union), France, Great Britain, and China, account for the remainder. India conducted one test in 1974. Tests have been conducted in the atmosphere, the unsaturated as well as saturated underground, and under water. Through a variety of treaties and moratoriums, the frequency and type of testing worldwide has changed significantly. The environmental legacy from testing has become a focus of concern and interest, in the private sector as well as in many world governments.

Environmental concerns have largely focused on risks to human health and the environment from past testing, recent and ongoing testing, and various kinds of testing planned for the future. Post-event studies have included efforts to characterize environmental risks at specific nuclear-testing sites as well as areas worldwide because of fallout primarily from atmospheric nuclear testing. Environmental restoration efforts have largely focused on site-specific characterization, risk evaluation, computer modeling, and environmental monitoring. There have been some environmental cleanup efforts initiated, particularly by the U.S. at its testing sites at the Nevada Test Site (NTS) and other locations outside of the continental U.S. and by Australia at Maralinga. These efforts and the efforts of other countries are described. The outlook for future environmental restoration of nuclear testing sites including continued characterization, modeling, monitoring, and cleanup is summarized. The challenges facing such efforts including the extent of contamination, the volumes of media involved, available and developing technologies, and economic and political constraints are summarized.

With the signing of the Comprehensive Test Ban Treaty (CTBT), the world entered an era of taking responsibility for the consequences of the Cold War, particularly the testing era. The legacy of nuclear testing is worldwide both from a geographic and environmental perspective. The major nuclear powers including the United States, the former Soviet Union, United Kingdom, France, China and to lesser extent, India, have all conducted nuclear testing. These tests have been conducted principally to develop nuclear weapons although some tests have focused on potential peaceful uses of nuclear devices. These tests have been performed in the atmosphere, under water, and underground. A summary of known nuclear testing by country and type is provided in Table I. With the implementation of the CTBT, most major nuclear-testing programs have ceased.

The environmental legacy left by such testing affects almost every major continent and several locations in the oceans of the world. A visual picture of the worldwide distribution of these test sites is provided in Figure 1. The extent of environmental effects of fallout from testing at these sites is even more pervasive. For purposes of this session, we will focus principally on the geographic locations and immediate environs of the test locations. It is the restoration of these test sites which is the subject of this presentation and which is the topic of this session of Waste Management '98.

Fig. 1. Distribution of Nuclear Test Sites Worldwide

The United States Department of Energy (DOE) and Australia have taken the lead in investigating and developing programs to address the environmental restoration of major test sites. Interestingly enough, the major test sites in these two countries, the NTS and Maralinga, are both located in arid environments or deserts (Figure 2).

A comparison of test sites around the world reveals similarities in testing environments (Table II). Similarities exist among the NTS, Australian sites, those found at Semipalatinsk in the former Soviet Union, at Lop Nur in China, French tests in Algeria near Reggane, and near Pokharan, India. Likewise, island testing sites in the Pacific Ocean (French Polynesia, the Marshall Islands, Christmas Island, and Johnson Atoll) have similarities in the island environments. Other island test sites include Novaya Zemlya in Russia's northern reaches and the United States tests at Amchitka Island, Alaska.

The environmental challenges vary from site to site, but there are patterns and similarities in the types of testing and their associated impacts. The environmental legacy and the challenges facing cleanup efforts associated with the various types of testing are summarized in Figure 3. The extent of impacts from atmospheric tests is worldwide. The cleanup of the legacy associated with atmospheric testing and safety tests has had a regional or site-specific focus. Characterization and remediation of surface soils and regional surface contamination have been the focus of efforts at the NTS and Maralinga. The efforts to cleanup surface soil contamination at these two sites will be reported during this session. The impacts of underwater testing have also been studied, particularly at certain island sites and locations in the Pacific Ocean. Similarities exist in areas of Russia and the U.S. where testing has been conducted in both vertical shafts and horizontal tunnels in the underground environments. In Russia and in the U.S., attention to groundwater contamination has involved an approach including groundwater modeling and monitoring efforts, the results of which are being reported at this conference, both at this session and in other sessions.

Many factors are when planning the approach to clean up and restore the world's nuclear test sites. The factors include environmental regulations; pressure from local populations, environmental interests and groups; politics; and worldwide efforts of health and environmental organizations (Table III). Typical of the constraints and problems associated with cleanup and restoration efforts to date are such issues as the enormity or extensiveness of the areas involved, regulatory drivers and cleanup levels, economics, potential risks to workers and the public, and technical challenges associated with characterization and cleanup activities. There are varying degrees to which each of these factors contributes to efforts within the different countries involved. Just as complicated is the ability of these nations to provide the resources necessary to do the clean up. One paper will be presented in this afternoon's session that addresses clean up standards.

Major cleanup approaches taken to date include efforts at Maralinga in Australia, the NTS in the U.S., and at Johnson Atoll and Bikini in the Pacific. Efforts have been made at other specific sites at various locations (Table IV). Historically, the methods used in some of the initial cleanup attempts are burial, the bulldozing of contaminated surface soils into trenches, or capping of the surface-contaminated areas. More recently, efforts have included excavation, containerizing and landfill disposal, bulk transport, bulk disposal in test craters, and in situ vitrification.

Table IV. Some Environmental Cleanup Alternatives Used at Test Sites in Australia and the U.S.

A number of characterization, modeling, collection, treatment, disposal, and monitoring techniques and technologies are being developed or modified which have or will provide some innovative solutions to contamination problems associated with environmental restoration at nuclear testing sites (Table V). The issue at hand is what institutional controls and actions will be effective in assuring national resources are being fully utilized.

In this afternoon's session, we will hear about some of the efforts that are underway for:

• the cleanup of plutonium-contaminated soils at the NTS and Tonopah Test Range in Nevada
• the cleanup of plutonium contaminated soils at Maralinga
• the cleanup of contaminated soil and coral at Johnson Atoll
• the in situ vitrification of contaminated sites at Taranaki, Australia
• the study of radionuclide contamination at Semipalatinsk in Kazakstan

There has been significant initial effort in characterization, modeling, and environmental monitoring. Characterization efforts have involved utilization of standard field techniques and remote sensing techniques. The extensive nature of both surface and subsurface distribution of contaminants presents technical and economic challenges that will test our capabilities and our innovative thinking. Environmental modeling has helped us begin to understand the complexities of fate and transport of contaminants and the fact that there are significant uncertainties with regard to how contaminants move and are transported in the environment. This is a long, costly process of prediction and verification. Figure 4 represents the results illustrated by a regional model developed at NTS and provides a prediction of the multiple groundwater flow paths that may transport contaminants beneath the NTS (being reported in another session at this conference). The development and use of such models has identified some of the technical complexities and uncertainties involved in fully understanding the challenge we face in the cleanup of the testing legacy.

Environmental monitoring efforts have continued to increase and are helping to delineate the extent and nature of the legacy and problems we face. The long-term utilization of monitoring programs may be one of the methods to protect public health and the environment. We have learned much but have much more to learn in the future.

This session, includes presentations by people who are involved in the remediation of the cold war legacy, and has been developed to instill a vision of global cooperation to repair the consequences of the nuclear-testing era. The vision is united restoration efforts lead by the United States, Australia, and those of us here who have developed and initiated these projects at various nuclear test sites. The sharing of approaches, techniques, technologies, and lessons learned will provide opportunities for innovative and forward thinking, leading to solutions to the peculiarities of contaminant cleanups at nuclear-testing sites. Coordinating and combining efforts at test sites where testing configurations and environments are similar allow us to enhance our effective use of knowledge and experience. There are opportunities to step up and lead the worldwide effort to address the legacy created by nuclear testing. We have the knowledge and experience to advance this effort and gain substantial reward. We have only just begun. The technical challenges may be minuscule compared to the political challenges of providing leadership to repair the legacies left behind. Perhaps the next international cooperative agreement is the Comprehensive Test Site Remediation Treaty among nuclear states.

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