Radiation is used in many different industries, including as fuel for nuclear power plants and in the production of nuclear weapons for national defense. These uses generate nuclear waste, and this waste must be disposed of in safe and effective ways. There are three main types of nuclear waste—high-level, transuranic, and low-level waste—and each type must be disposed of according to its risk to human health and the environment. For instance, high-level nuclear waste remains highly radioactive for tens of thousands of years and must be disposed of in such a way that it can be securely isolated for a long period of time.
The Department of Energy (DOE) oversees the treatment and disposal of radioactive waste from the nation’s nuclear weapons program; it is also responsible for siting, building, and operating a geologic repository to dispose of nuclear waste. There are a number of ways that DOE could improve how it stores, treats, and disposes of this waste.
- The nation has over 85,000 metric tons of spent nuclear fuel from commercial nuclear power plants. DOE is responsible for disposing of this high-level waste in a permanent geologic repository but has yet to build such a facility because policymakers have been at an impasse over what to do with this spent fuel since 2010. As a result, the amount of spent nuclear fuel stored at nuclear power plants across the country continues to grow by about 2,000 metric tons a year. Meanwhile, the federal government has paid billions of dollars in damages to utilities for failing to dispose of this waste and may potentially have to pay tens of billions of dollars more in coming decades. If Congress were to authorize a new consent-based process for siting a repository, it could help break the impasse over a permanent solution for commercial spent nuclear fuel.
- DOE also oversees the treatment and disposal of about 90 million gallons of radioactive waste from the nation's nuclear weapons program. Most of this waste is stored in tanks at 3 DOE sites. According to federal law, certain high-level mixed waste must be vitrified—a process in which the waste is immobilized in glass—and disposed of in a deep geologic repository. However, DOE estimates that about 90% of the volume of this waste contains about 10% of the radioactivity. DOE considers this portion of the waste to be low-activity waste, which experts believe may be safely treated and disposed of with methods other than vitrification. Nevertheless, DOE plans to vitrify a portion of this low-activity waste at its Hanford Site in Washington State but may face challenges starting operations of a treatment facility to do so. In addition, DOE may be able to reduce certain risks and save tens of billions of dollars by adopting alternative approaches to treating and disposing of a portion of Hanford’s low-activity radioactive waste. DOE has also faced challenges designing and building high-level waste treatment facilities at Hanford and Idaho National Laboratory. Additionally, the United States will continue to generate new high-level defense waste as a result of its ongoing weapons program and efforts to modernize the nuclear stockpile.
The Partially Constructed Hanford Pretreatment Facility in Washington State, 2013 and 2020
- Transuranic nuclear waste is waste contaminated by nuclear elements heavier than uranium, such as diluted plutonium. The United States has only one deep geologic repository for the disposal of defense-related transuranic waste—the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. However, DOE has experienced challenges constructing a new ventilation system and may face delays in expanding WIPP to dispose of all defense transuranic waste.
Underground tunnel at the geologic repository for defense waste in New Mexico
- Low-level waste may be generated from both civilian and defense activities. Low-level waste is generally defined as waste that is not high-level or transuranic waste. Low-level waste decays rapidly and can typically be disposed of in a near-surface disposal facility. Three gaseous diffusion plants—located near Paducah, Kentucky; Portsmouth, Ohio; and Oak Ridge, Tennessee—at one time enriched uranium for both defense and civilian purposes. However, these plants were rendered obsolete by newer, more efficient technologies. As DOE decontaminates and decommissions these facilities, it generates significant amounts of waste, including building materials and hazardous and radioactive waste removed from equipment and piping. Much of this waste is considered to be low-level waste and must be disposed of at a low-level waste disposal facility. However, DOE’s fund to clean up these plants is likely not large enough—cleanup costs may exceed the amount in this fund by $45 billion. In addition, DOE is working to convert DUF6 (a dangerous byproduct of the uranium enrichment process) into a more stable chemical form that can be disposed of or reused. DOE estimates it could cost at least $7.2 billion to convert and dispose of the DUF6 as low-level waste. If DOE can transfer portions of its DUF6 inventory—such as by selling some to a private company—it could save billions. However, it is unclear if DOE has authority to sell depleted uranium. Moreover, DOE is responsible for disposing of certain low-level nuclear waste from medical equipment, metals in nuclear reactors, and cleanup sites—commonly referred to as greater-than-class C waste. However, no legal options currently exist to dispose of this waste.