GAO Report: Nuclear Waste Cleanup Definition Clarification Needed
Summary
The GAO has released a report highlighting ambiguities in the Department of Energy's (DOE) statutory definition of "high-level radioactive waste" that hinder its cleanup mission. The report suggests that clarifying this definition could lead to significant cost savings, potentially in the tens of billions of dollars, by allowing more waste to be treated and disposed of as less expensive low-level or transuranic waste.
What changed
The Government Accountability Office (GAO) has issued a report (GAO-26-108018) identifying critical ambiguities within the Department of Energy's (DOE) statutory definition of "high-level radioactive waste" (HLW). These ambiguities impede the DOE's Office of Environmental Management (EM) mission to clean up radioactive waste from nuclear weapons production, preventing the classification of certain waste as less expensive low-level radioactive waste (LLW) or transuranic (TRU) waste. The report notes that existing waste classification tools have shortcomings, such as not being applicable at the Hanford Site, and the lack of clarity poses litigation risks.
The GAO recommends that the DOE address these issues by clarifying the HLW definition, which could unlock significant cost savings estimated in the tens of billions of dollars. The report also points out that EM has not fully evaluated or pursued identified opportunities to expedite cleanup and reduce costs. The GAO suggests that any efforts to revise the HLW definition should involve input from experts across government, industry, and academia to ensure successful implementation and accelerate the cleanup mission.
What to do next
- Review GAO report GAO-26-108018 for detailed findings and recommendations.
- Assess internal processes for classifying radioactive waste against GAO findings.
- Monitor DOE's response and any potential regulatory or policy changes regarding HLW definitions.
Source document (simplified)
GAO-26-108018 Published: Mar 25, 2026. Publicly Released: Mar 25, 2026.
Fast Facts
The Department of Energy is responsible for cleaning up millions of gallons of radioactive waste from nuclear weapons production. To do this, DOE must rely on a statutory definition of "high-level radioactive waste" that is unclear and hinders its mission. For example, the definition doesn't define the phrase "highly radioactive."
There have been concerns about this definition for decades. And, DOE hasn't fully evaluated or pursued opportunities to save tens of billions of dollars in how it treats and disposes of this waste. Our recommendations address these issues.
Underground Storage Tank with Radioactive Waste
Inside an underground radioactive waste storage tank.
Highlights
What GAO Found
The Department of Energy’s (DOE) Office of Environmental Management (EM) is responsible for cleaning up waste resulting from the reprocessing of spent nuclear fuel, a process used to produce plutonium. Generally, EM manages this waste associated with reprocessing as if it is high-level radioactive waste (HLW) unless the waste can be classified as low-level radioactive waste (LLW) or transuranic (TRU) waste. LLW and TRU waste are expected to be less expensive to treat and dispose of compared with HLW. To classify its waste, EM relies in part on the statutory definition of HLW in the Atomic Energy Act of 1954, as amended, and the Nuclear Waste Policy Act of 1982, as amended. However, GAO, DOE, and others have raised concerns that ambiguities in this definition have impeded EM’s cleanup progress.
Examples of Waste Associated with Reprocessing
EM has three processes—known as waste classification tools—it can use to determine that certain waste associated with reprocessing can be treated and disposed of as LLW or TRU waste, rather than HLW. While these tools help EM address ambiguities in the HLW definition, they have shortcomings that hinder EM’s progress. For example, one tool cannot be used at the Hanford Site, EM’s most complex and expensive site. EM also faces the risk of litigation due to the lack of clarity in the HLW definition, which could affect EM’s ability to successfully use the tools. Until the HLW definition is clarified, EM will continue to face significant barriers to completing its cleanup mission. Given the complexity of this issue, any efforts to revise the HLW definition would benefit from input and ideas from experts across government, industry, and academia.
While EM has applied the three tools to treat and dispose of some waste associated with reprocessing as non-HLW, EM has not pursued additional opportunities that GAO and others have identified. Many studies over the last 2 decades—including analyses conducted by EM—have shown that opportunities exist for EM to expedite its cleanup efforts and realize significant cost savings while ensuring safe disposal. For example, in a 2020 report, EM estimated that classifying a portion of tank waste as LLW at its Hanford Site could potentially generate a cost savings of $73 to $210 billion. By systematically evaluating these opportunities and pursuing them to the maximum extent possible, EM could accelerate its cleanup mission and save at least tens of billions of dollars.
Why GAO Did This Study
Since 1989, EM has been responsible for cleaning up waste resulting from plutonium production for the nation’s nuclear arsenal. EM has faced many challenges in determining how best to treat and dispose of this waste, and the estimated future cost for addressing this and other waste is more than half a trillion dollars.
Senate Report 118-188 includes a provision for GAO to review DOE’s implementation of certain tools to treat and dispose of waste associated with reprocessing as something other than HLW. GAO’s report examines (1) EM’s efforts to treat and dispose of such waste and the barriers it faces in doing so and (2) potential opportunities to realize cost savings by treating certain waste as something other than HLW.
GAO analyzed laws, EM policies and documentation, and prior GAO and independent entities’ studies. GAO interviewed EM officials regarding EM’s plans to treat and dispose of waste associated with reprocessing. GAO also visited two EM sites and evaluated documentation to identify opportunities for EM to treat and dispose of certain waste as LLW or TRU waste.
Recommendations
GAO recommends that Congress consider convening a panel of experts to recommend specific revisions to the statutory definition of HLW to address ambiguities in the definition.
GAO also recommends that EM systematically evaluate opportunities to treat and dispose of certain waste associated with reprocessing as something other than HLW and communicate to Congress regarding its efforts to implement these opportunities as well as actions Congress can take to minimize or eliminate any barriers impeding EM’s ability to pursue them. DOE agreed with the recommendation.
Matter for Congressional Consideration
| Matter | Status | Comments |
| --- | --- | --- |
Recommendations for Executive Action
| Agency Affected | Recommendation | Status |
| --- | --- | --- |
| Office of Environmental Management | The Assistant Secretary for Environmental Management should systematically evaluate the full range of opportunities to treat and dispose of legacy waste associated with reprocessing as something other than HLW and communicate to Congress on (1) EM's plans to implement identified opportunities—or its rationale for not doing so—and (2) actions Congress can take to minimize or eliminate barriers that impede EM's ability to proceed with these plans. (Recommendation 1) | Open When we confirm what actions the agency has taken in response to this recommendation, we will provide updated information. |
Full Report
GAO Contacts
Nathan Anderson Director Natural Resources and Environment andersonn@gao.gov
Media Inquiries
Sarah Kaczmarek Managing Director Office of Public Affairs media@gao.gov
Public Inquiries
Topics
Natural Resources and Environment Radioactive wastes Nuclear waste Hazardous waste site remediation Storage tanks Spent nuclear fuel Agency evaluations Environmental management Disposal facilities Litigation Laws and regulations
Related changes
Source
Classification
Who this affects
Taxonomy
Browse Categories
Get Government & Legislation alerts
Weekly digest. AI-summarized, no noise.
Free. Unsubscribe anytime.
Get alerts for this source
We'll email you when GAO Reports publishes new changes.