Low-Activity Radioactive Wastes
"Low-Activity" Radioactive Wastes (LARW) are informally defined as radioactive wastes that contain very small concentrations of radionuclidesRadioactive forms of elements are called radionuclides. Radium-226, Cesium-137, and Strontium-90 are examples of radionuclides.. The concentrations are small enough that protection of public health and the environment from these wastes may not require all of the radiation protection measures necessary to manage higher-activity radioactive material. At this time, “low-activity” itself is a concept, not a definition. Among the wastes that could be addressed as “low-activity” are mixed wastesMixed waste contains both radioactive and hazardous waste components. (chemically hazardous and radioactive), wastes containing natural radioactivityThe emission of ionizing radiation released by a source in a given time period. The units used to measure radioactivity are curie (Ci) and becquerel (Bq)., cleanup wastes and other low-level radioactive wastes.
Present regulation of “low-activity” radioactive waste is inconsistent, often based on the origin of the waste. Besides inconsistent regulation, cost and availability of disposal affect the way low-activity wastes are managed.
On November 18, 2003, EPA published an Advance Notice of Proposed Rulemaking (ANPR) to collect public comment on alternatives for disposal of waste containing low concentrations of radioactive material (“low-activity” waste). EPA worked with the Department of Energy (DOE), the Nuclear Regulatory Commission (NRC) and NRC Agreement States in developing the ANPR.
The ANPR gathered public input on a variety of regulatory, technical and disposal options for ensuring protection of public health and the environment. It also asked for input on defining LARW. It did not propose regulatory language or a specific regulatory approach.
The ANPR posed the question of whether certain types of disposal facilities, particularly hazardous waste landfills permitted under Subtitle C of the Resource Conservation and Recovery Act (RCRA) may be able to offer appropriate protection for disposal of low-activity radioactive wastes.
View the ANPR in the Federal Register.
View supporting documents and public comments in EPA's electronic docket (EPA-HQ-OAR-2003-0095) on Regulations.gov.
In the ANPR for Low-Activity Radioactive Waste, each of the following types of waste was given a distinct meaning though not necessarily a regulatory or statutory definition.
Low-Level Radioactive Waste (or LLRW) is a regulatory term defined as the broad group or class of radioactive waste that is not included in the following classes of radioactive waste:
- Spent nuclear fuelFuel that has been withdrawn from a nuclear reactor after use. It is still highly radioactive..
- High-level waste.
- Transuranic waste.Waste materials containing elements with atomic numbers higher than uranium (92) at concentrations greater than 100 nCi/g.
- Uranium and thorium mill tailingsThe remaining portion of a metal-bearing ore after some or all of a metal, such as uranium, has been extracted..
The term is often confusing. It is easy to equate “low-level radioactive” with “low radioactive content”. However, there is no limit on the amount of radioactive material that can be contained in “low-level” radioactive waste. LLRW and a simpler term that is often used, “low-level waste” (LLW), refer to the same radioactive material.
LLRW is regulated under the Atomic Energy Act of 1954. The Nuclear Regulatory Commission (NRC) and NRC Agreement States regulate commercial disposal of LLRW in near-surface disposal facilities. The Department of Energy (DOE) regulates disposal at its own sites.
“Low-Activity” Radioactive Waste (LARW) refers to a category of radioactive wastes that contain very small concentrations of radionuclides. The concentrations are small enough that managing these wastes may not require all of the radiation protection measures necessary to manage higher-activity radioactive material to be fully protective of public health and the environment. Several classes of radioactive waste that contain small enough concentrations of radionuclides may be considered low-activity waste. (See "Possible Sources" above.) The ANPR discusses possible ways to determine when concentrations are “small enough.”
Mixed Low-Level Radioactive Waste, Mixed Low-Level Waste or, for the purposes of the ANPR, Mixed Waste (MW) is low-level radioactive waste that also contains components that are chemically hazardous according to the Resource Conservation and Recovery Act (RCRA). Such waste is regulated and managed under both RCRA and the Atomic Energy Act of 1954. This dual regulation is a major reason for the limited number of mixed waste disposal facilities.
“Low-Activity” Mixed Waste (or LAMW) means MW whose radioactive component qualifies as LLRW and whose radionuclide concentrations are “small”. The limits on the radionuclide concentrations that may be considered “small” would be developed using the general concepts and considerations described in the ANPR.
Radioactive wastes from several sources have the potential to meet criteria that would define “low-activity” wastes:
Naturally Occurring Radioactive MaterialsMaterials found in nature that emit ionizing radiation that have not been moved or concentrated by human activity. (NORM) extracted from the earth through mining, drilling, or pumping are processed to create a product. The NORM may be the resource of interest or it may be associated with non-radioactive resources, such as petroleum. The extraction and the processing create Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) wastes, NORM that has been concentrated or exposed by human activity. Some of these wastes may be “low-activity”.
Wastes from milling NORM to extract uranium or thorium may be subject to the Uranium Mill Tailings Radiation Control Act (UMTRCA). “Pre-UMTRCA” byproduct materials are wastes from milling operations that were produced at non-Department of Energy sites which had largely ceased production prior to the passage of UMTRCA. Certain pre-UMTRCA byproduct materials may be candidate “low-activity” radioactive wastes.
Source Material from Commercial Facilities
Source material produced by uranium mills for commercial purposes is subject to regulation by the Nuclear Regulatory Commission (NRC). It is used in the nuclear fuel cycle, research and industry. (Source material having less than 0.05% uranium or thorium by weight is not actively regulated by NRC.) Radionuclides produced in some of the low-level and mixed-wastes generated by these processes may be candidates for designation as “low-activity” wastes. Individual radionuclides generated by these process may be used for research and industrial purposes. After their use, they become low-level waste or mixed-waste which may be candidate “low-activity” radioactive wastes.
Source Material from DOE Research and Defense Facilities
Source material produced by DOE facilities is subject to DOE regulation and used in research and defense programs. Some individual radionuclides from research are reused for other research or for industrial purposes. Radionuclides produced from research ultimately become low-level waste or mixed waste that may be candidate “low-activity” radioactive wastes. Transuranic wastes from defense programs will be stored in DOE's Waste Isolation Pilot Plant (WIPP). High-level wastes from these programs will be disposed of in DOE's Yucca Mountain repository.
Radioactive materials for research and industry are also produced by accelerators. These materials are not subject to the Atomic Energy Act (AEA). Wastes from their production and use are non-AEA wastes and may also be candidate “low-activity” radioactive wastes.
Low-activity wastes can also be generated from medical applications and from clean up and reclamation of sites where radioactive materials were used in industrial and government activities. Large quantities of cleanup wastes from DOE sites are currently being disposed of at those sites. However, for locations that do not offer settings where adequate containment and isolation can be assured, these wastes may also be candidates for disposal as low-activity wastes.