Radioactive Waste Management/Mixed Waste
According to the United States United States Environmental Protection Agency|Environmental Protection Agency, mixed waste (MW) is a waste type defined as follows; "MW contains both hazardous waste (as defined by RCRA and its amendments) and radioactive waste (as defined by AEA and its amendments). It is jointly regulated by NRC or NRC's Agreement States and EPA or EPA's RCRA Authorized States. The fundamental and most comprehensive statutory definition is found in the Federal Facilities Compliance Act (FFCA) where Section 1004(41) was added to RCRA: "The term 'mixed waste' means waste that contains both hazardous waste and source, special nuclear waste|nuclear, or byproduct material subject to the Atomic Energy Act of 1954."
Mixed waste is much more expensive to manage and dispose of than waste that is solely radioactive. Waste generators can avoid higher charge back costs by eliminating or minimizing the volume of mixed waste generated.
A dual regulatory framework exists for mixed-waste, with the EPA or authorized states regulating the chemically hazardous portion of the waste and the U.S. Nuclear Regulatory Commission (NRC), the NRC agreement states, or the U.S. Department of Energy (DOE) regulating the radioactive portion of the waste.
- NRC generally regulates commercial and non-DOE federal facilities and their wastes.
- DOE is currently largely self-regulating in the management of its wastes through its Environmental Management program. The exception is the Waste Isolation Pilot Plant (WIPP) for which EPA has regulatory oversight. DOE wastes are largely legacy wastes from the development of nuclear weapons. DOE's orders apply to DOE sites and contractors who work at those facilities.
NRC and DOE use their authority under the Atomic Energy Act (AEA) to regulate the radioactive components of mixed-waste. EPA uses its authority under the Resource Conservation and Recovery Act (RCRA) authority to regulate the hazardous waste portion. NRC is authorized by the AEA to issue licenses to commercial users of radioactive materials. RCRA gives EPA the authority to control hazardous waste from "cradle-to-grave."
Once a waste is determined to be a mixed-waste, the waste handlers must comply with both AEA and RCRA regulations. The requirements of RCRA and AEA are generally consistent and compatible. However, the provisions in Section 1006(a) of RCRA allow the AEA to take precedence in the event provisions of the two acts are found to be inconsistent. Sources of Mixed-Waste
Mixed-waste can be generated anywhere radioactive materials are used in processes that also involve the use of chemically hazardous materials. There are two primary sources of mixed-waste:
- low-level mixed-waste generated by commercial users
- low-level, high-level, and transuranic mixed-waste generated by the Department of Energy
Commercially Generated Low-Level Mixed-Waste
The radioactive component of almost all commercially-generated mixed-waste is low-level radioactive waste (LLRW). It is referred to as "Low-Level Mixed-Waste (LLMW);" it is produced in all 50 states.
Industrial, hospital, and nuclear power plant facilities use both radioactive and hazardous materials in a number of processes:
- medical diagnostic testing and research
- pharmaceutical and biotechnology development
- pesticide research
- nuclear power plant operations
The Nuclear Regulatory Commission and EPA conducted a survey of commercial mixed-wastes, (National Profile of Commercially Generated Mixed-Waste). The results provided a cross-section of the approximately 4,000 cubic meters (m3) of LLMW generated in the United States in 1990:
- liquid scintillation cocktail (LSC)-71%
- organic solvents such as chlorofluorocarbons, corrosive organics, and waste oil-18%
- toxic metals-3%
- "other" waste-8%
The amount of mixed-waste generated by commercial facilities is very small (about two percent of the total) compared to the amount generated or stored by Department of Energy facilities.
Under the 1984 Amendments to RCRA, Land Disposal Restriction (LDR) regulations prohibit disposal of most mixed-waste including LLMW until it meets specific treatment standards. While most of the commercial mixed-waste that is generated and stored can be treated to meet the LDRs by commercially available treatment technology, there still exists a small percentage of commercial mixed-waste for which no treatment or disposal capacity is available.
Department of Energy Mixed-Waste
DOE facilities primarily produce and/or stores three types of mixed-waste:
DOE's low-level mixed-waste (LLMW) is generated, projected to be generated, or stored, at 37 DOE sites in 22 states. It comes from research, development, and production of nuclear weapons. Waste management activities will require management of an estimated 226,000 cubic meters (m3) of LLMW over the next 20 years.
DOE's high-level waste (HLW) is radioactive waste which is liquid prior to treatment and comes from reprocessing spent nuclear fuel and irradiated targets from reactors. Some of its elements will remain radioactive for thousands of years. Because it contains highly corrosive, organic, or heavy metal components that are regulated under RCRA, this HLW is considered a mixed-waste.
DOE's HLW is stored in large tanks at four locations:
- Hanford, Washington (50,000,000 gallons)
- Idaho National Laboratory, Idaho (900,000 gallons)
- Savannah River Site, South Carolina (36,000,000 gallons)
DOE has treated some of the HLW by processing it into a solid form (e.g. borosilicate glass) that is not readily dispersible into the air or leachable into the ground or surface water. This treatment process is called vitrification. Between 1996 and 2001, the approximately 660,000 gallons of highly radioactive liquid waste stored at West Valley was vitrified. The vitrification process will ultimately generate approximately 29,000 canisters for disposal in a geologic repository. Currently, Yucca Mountain, Nevada, has been identified as the site for a potential geological repository. EPA's Yucca Mountain Standards pages contain information about the Agency's standards-setting role in the project.
Mixed Transuranic Waste
DOE mixed transuranic waste (MTRU) is waste that has a hazardous component and radioactive elements heavier than uranium. The radioactivity in the MTRU must be greater than 100 nano Curies per gram (nCi/g) and contaminated with RCRA hazardous constituents. The principle hazard from MTRU is alpha-particle radiation through inhalation or ingestion.
MTRU is primarily generated from nuclear weapons fabrication, plutonium-bearing reactor fuel fabrication, and spent fuel reprocessing. The amount of MTRU generated by entities other than DOE is negligible. Approximately 55% of DOE's TRU waste is mixed-waste. Approximately 1,500 m3 of MTRU from Rocky Flats, Colorado has been retrieved for disposal and the site is closed. MTRU is currently being retrieved for disposal at five DOE sites:
- Hanford, Washington (3,000 m3)
- Idaho National Laboratory (38,000 m3)
- Los Alamos National Laboratories, New Mexico (8,000 m3)
- Oak Ridge National Laboratory, Tennessee (1,500 m3)
- Savannah River Site (5,000 m3)
DOE disposes defense-related MTRU at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. Before DOE can dispose of waste at the WIPP, it must demonstrate that the waste has been characterized in compliance with the EPA regulations at 40 CFR 194 and meets EPA's radioactive waste disposal standards (40 CFR 191). EPA approved DOE's initial compliance certification application (CCA) in May 1998. DOE must submit a Compliance Recertification Application (CRA) every five years to demonstrate that the WIPP continues to comply with EPA's TRU waste disposal standards. DOE's first recertification was approved by EPA in March 2006. The next recertification process will occur in 2009.
Treatment of DOE's Mixed-Waste
DOE's 1995 Baseline Environmental Management Report estimated that the life-cycle costs for HLW, TRU (including MTRU), and LLMW were $34 billion, $13 billion, and $13 billion respectively over a 75 year period.
As mandated by the Federal Facilities Compliance Act (FFCA), which was signed into law on October 6, 1992, DOE has developed Site Treatment Plans for its mixed-wastes. DOE is implementing these plans through orders issued by EPA or the states. It also developed a Waste Management Programmatic Environmental Impact Statement (WM PEIS) for treatment, storage, and disposal of radioactive and hazardous waste. This plan will assist DOE in selecting waste management facilities. DOE, EPA, NRC, and the states will continue to work together to ensure the proper management and disposal of legacy wastes from the Cold War.
Choosing the Right Regulations: Federal vs. State
EPA RCRA Authorized States
In general, facilities that manage mixed-waste are subject to one of two sets of hazardous waste regulations:
- the federal RCRA Subtitle C requirements for hazardous waste in 40 CFR part 124 and parts 260-270
- comparable regulations of states or territories that have RCRA mixed-waste authority.
You can learn more about the authorization process on EPA's RCRA State Authorization page. You can determine whether your state has EPA RCRA and mixed-waste authorization from EPA's State Authorization Tracking System (StATS).
Knowing whether your state has RCRA authorization and even RCRA mixed-waste authorization may not alert you to all requirements. You should also contact the following organizations:
- your state radiation control program to identify any state regulations that apply to mixed-waste. Exit EPA Disclaimer
- the appropriate EPA Region to determine whether there are aspects of the RCRA program for which the state has not been authorized and for which the region shares responsibility. (For example, certain requirements under the Hazardous and Solid Waste Amendments of 1984, such as corrective actions and land disposal restrictions
If your state is authorized, then your state runs the program. If not, EPA has jurisdiction. Even when states have authorization, there may be aspects of the program that EPA retains authority over. NRC Agreement States
Many states have signed agreements with the Nuclear Regulatory Commission authorizing them to regulate source, by-product and small quantities of special nuclear material within their boundaries. They have agreed to adopt programs that are at least as stringent as NRC's and may have additional requirements.
Most Agreement States have requirements that apply to most source, special nuclear, and byproduct material. (Exceptions are materials from nuclear utilities and fuel cycle facilities, which are regulated by NRC, and materials from DOE facilities, which are regulated by DOE Orders.) You can determine whether your state is an NRC Agreement State and determine the scope of the program that has been relinquished by NRC to the state by contacting the radiation control program for your state Exit EPA Disclaimer.
US EPA hazardous waste definition
The EPA defines hazardous waste as the following: A subset of solid wastes that pose substantial or potential threats to public health or the environment and meet any of the following criteria identified 40 CFR 260 and 261:
- It is specifically listed as a hazardous waste by EPA
- It exhibits one or more of the characteristics of hazardous waste (ignitability, corrosivity, reactivity, and/or toxicity);
- It is generated by the treatment of hazardous waste; or is contained in a hazardous waste.