Appendix B

THE ENVIRONMENTAL LEGACY

INTRODUCTION

During World War II and the Cold War, the manufacture of nuclear weapons progressed through a wide series of research, testing, and production at laboratories, chemical plants, nuclear reactors, machine shops, and test sites throughout the United States. The resulting environmental legacy includes radioactive and hazardous waste contamination, numerous contaminated buildings, and unneeded materials at many installations across the nation. The risks to human health and the environment from these activities vary from negligible to substantial.

Although the primary responsibility of the Environmental Management program is to address the risks posed by past nuclear weapons production activities, the program must also attend to contaminants resulting from activities outside the nuclear weapons production complex. The program must, for example, address hazardous and/or radioactive waste from nonweapons sources, including energy research, basic science, and the Three Mile Island nuclear power plant accident. The program also manages newly generated radioactive waste from ongoing programs throughout the Department of Energy, as well as spent nuclear fuel generated by the U.S. Naval Nuclear Propulsion Program and foreign research reactors.

The Department of Energy is preparing an Environmental Impact Statement to determine whether to adopt and implement a policy concerning management of additional spent fuel from domestic and foreign research reactors that contain uranium enriched in the United States. This effort is in support of the United States' nuclear nonproliferation policy. A Record of Decision concerning the foreign research reactor fuel is anticipated in April 1996.

In the future, the Environmental Management program will manage waste from weapons dismantlement and related maintenance activities. This appendix describes the environmental legacy of nuclear weapons production in the United States.

THE CAUSES OF THE ENVIRONMENTAL LEGACY

Perhaps the most important characteristic of the environmental legacy of nuclear weapons production is its dynamic nature. The environmental cost of 40 years of weapons production represents nearly 80 percent of the Environmental Management program's responsibilities. The balance results from activities similar to, but outside the realm of, nuclear weapons production. The scope of the environmental legacy has grown over many years. Today, contamination is being removed from the land, remediated in place, or contained to prevent its further spread; old facilities are being decontaminated, dismantled, and demolished; stored waste is being disposed of even as new waste is being generated; uncontained contamination is spreading by natural dispersion; and radioactive materials and chemical contaminants are decaying or deteriorating as time passes.

SOURCES OF CONTAMINATION

The process of manufacturing nuclear weapons relied on the production of three materials: highly enriched uranium, plutonium, and tritium. Production of these materials took place at an array of facilities throughout the United States. Nuclear weapons production at facilities such as the Plutonium Uranium Reduction Extraction Plant at Hanford Site, Washington; Building 771 at the Rocky Flats Environmental Technology Site near Denver, Colorado; and the F and H Canyons at the Savannah River Site in South Carolina resulted in the largest sources of contamination.

Figure B.1 shows the scope of the Environmental Management program. The following is a brief description of each step in the nuclear weapons manufacturing process, and the resulting contamination:

Figure B.1. The U.S. Department of Energy Environmental Program: Responsibilities from Coast-to-Coast and Beyond

Uranium Mining and Milling: Approximately 54.4 metric tons (60 million tons) of uranium ore were mined and milled in the United States for nuclear weapons production, primarily in western states. Most of this activity was carried out in the 1950s and 1960s. The environmental legacy of these operations includes large volumes of a sand-like byproduct known as "mill tailings," which contain toxic heavy metals and radioactive radium and thorium. The radioactivity present is a small fraction of the total radioactive material managed by the Environmental Management program. However, because of wind-blown waste and the use of some tailings in construction and landscaping projects, the contamination from these tailings affected thousands of individual sites.

Uranium Enrichment: At uranium enrichment plants in Ohio, Kentucky, and Tennessee, the mined and milled uranium-238 was enriched and separated to produce weapons-grade uranium-235 in the form of uranium hexafluoride gas. The environmental legacy of the enrichment process includes depleted uranium, large volumes of radioactive and hazardous waste, and facilities contaminated with radioactive materials, solvents, polychlorinated biphenyls, heavy metals, and other toxic substances.

Fuel and Target Fabrication: The uranium hexafluoride gas produced at the enrichment plants was converted into metal (uranium targets) at fuel and target fabrication facilities in the States of South Carolina and Washington. The environmental legacy of this step in the production of nuclear weapons includes unintended releases of uranium dust, landfills contaminated with hazardous chemicals, and facilities contaminated with radioactive and hazardous materials.

Reactor Irradiation: The uranium targets from fuel and fabrication plants were irradiated in 14 production reactors in the States of South Carolina and Washington to produce plutonium. This step produced radioactive spent fuel and radioactive contamination of reactor and storage facilities near large rivers.

Chemical Separation: The fission products and uranium and plutonium from spent fuel were reprocessed at chemical separation facilities in the States of Washington, Idaho, and South Carolina. This step in the production process generated approximately 385 million liters (100 million gallons) of highly radioactive and hazardous chemical waste. Some of this waste was discharged directly into the ground or stored in underground storage tanks. Some of the waste in underground storage subsequently leaked. This waste represents the vast majority of the radioactivity for which the Environmental Management program has responsibility. Many of the radioactive elements in this waste are long-lived and will pose risks to human health and the environment for tens of thousands of years. Contaminated facilities also have resulted from chemical separation.

Fabrication of Weapons Components: Plutonium was machined into warhead components at facilities in the States of Colorado, Washington, and Tennessee. Laboratories associated with the production complex also used plutonium to make and test weapons prototypes. This part of the production process resulted in transuranic waste and contaminated facilities.

Fabrication of Nonnuclear Weapons Components: Nonnuclear components required for weapons assembly were manufactured at plants in Texas, Missouri, Ohio, and Florida. Soil contamination from high-explosive waste, fuel and oil leaks, and solvents resulted from this part of the process.

Weapons Assembly, Disassembly, and Maintenance: Final assembly of nuclear warheads in Texas and Iowa resulted in radioactive and hazardous chemical contamination of facilities. In the years ahead, dismantling nuclear weapons at the Department's weapons assembly facilities will generate radioactive and chemical waste that must be safely managed. In addition, throughout the Cold War the government contracted with private firms to perform research and manufacturing, usually related to nuclear weapons production. As a result, radioactive contamination occurred at 46 sites in 14 states. These sites are collectively referred to as "formerly utilized sites."

Research, Development, and Testing: Between 1945 and 1992, over 1,000 nuclear devices were exploded in atmospheric, underwater, and underground tests. Most of the nuclear weapons tests were conducted in Nevada, but tests were also carried out in the Pacific and South Atlantic Oceans, Alaska, and New Mexico. Nuclear explosion tests were also conducted in Colorado, New Mexico, Mississippi, and Alaska for nonweapons purposes. The environmental legacy of these tests includes hundreds of highly radioactive underground craters as well as soil and debris contaminated with low-level radioactive waste. Nonnuclear weapons components were also tested, leaving a legacy of contamination from high-explosive materials and other chemicals.

Chapter -1- / -2- / -3- / -4- / -5- / -6- / -7- / -8-

Appendix -A2- / -B- / -C- / -D- / -E1- / -E2- / -F- / -G- / -H- / Glossary