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An Overview of Mixed
Waste
Mixed
waste contains radioactive and hazardous waste. A dual
regulatory framework exists for mixed waste, with the U.S.
Environmental Protection Agency (EPA) or authorized states
regulating the hazardous
waste and the U.S.
Nuclear Regulatory Commission (NRC), NRC agreement states, or
the U.S.
Department of Energy (DOE) regulating the radioactive waste. NRC
generally regulates commercial and non-DOE federal facilities. DOE
is currently self-regulating and its orders apply to DOE sites and
contractors. The DOE
Advisory Committee on External Regulation recently published its
final report titled, "Improving Regulation
of Safety at DOE Nuclear Facilities (12/95)." This report
debates whether and how DOE facilities may come under external
regulation.
Using the Atomic
Energy Act (AEA) authority, NRC and DOE regulate mixed waste
with regard to radiation safety. Using the Resource,
Conservation, and Recovery Act (RCRA) authority, EPA regulates
mixed waste with regard to hazardous waste safety. 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
statutes and 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 requirements of the two acts are found to be
inconsistent.
Almost all of the commercially generated (non-DOE) mixed
waste is composed of
Low-Level Radioactive Waste (LLRW) and Hazardous
Waste and is called Low Level Mixed Waste (LLMW). Commercially
generated LLMW is produced in all 50 states at industrial, hospital,
and nuclear power plant facilities. Radioactive and hazardous
materials are used in a number of processes such as medical
diagnostic testing and research, pharmaceutical and biotechnology
development, pesticide research, as well as nuclear power plant
operations. Based on the results of a survey conducted by NRC &
EPA (NUREG/CR-5938),
approximately 4,000 m3 of LLMW were generated in the U.S.
in 1990. Of this amount, approximately 2840 m3 (or 71%)
was liquid
scintillation cocktail (LSC). Organic solvents such as
chlorofluorocarbons (CFC's), corrosive organics, and waste oil made
up 18%, toxic metals made up 3%, and "Other" waste made up the
remaining 8%.
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 LDR's by
commercially available treatment technology, there still exists a
small percentage of commercial mixed waste for which no treatment or
disposal capacity is available. Commercial mixed waste volumes are
very small (approximately 2%) compared to the total volume of mixed
waste being generated or stored by DOE.
There are three main types of mixed waste being produced or
stored at DOE facilities, Low-Level, High Level, and Transuranic.
DOE Low-Level
Mixed Waste (LLMW) is generated, projected to be generated, or
stored, at 37 DOE sites in 22 states as a result of research,
development, and production of nuclear weapons. Waste management
activities will require management of an estimated 226,000
m3 of LLMW over the next 20 years.
DOE High
Level Waste (HLW) is radioactive waste resulting from
reprocessing spent nuclear fuel and irradiated targets from reactors
and is liquid before it is treated. Some of its elements will remain
radioactive for thousands of years. HLW is also a mixed waste
because it has highly corrosive components or has organics or heavy
metals that are regulated under RCRA. DOE has about 399,000
m3 of HLW stored in large tanks at four locations:
Hanford, Washington; Idaho National Engineering Laboratories (INEL),
Idaho; Savannah River Site (SRS), South Carolina; and the West
Valley Demonstration Project, New York. DOE is proceeding with plans
to treat HLW by processing it into a solid form (e.g. borosilicate
glass) that would not be readily dispersable into the air or
leachate into the ground or surface water. This treatment process is
called vitrification.
The vitrification process will generate approximately 29,000
canisters to be disposed of in a geologic repository. Currently Yucca
Mountain, Nevada, is being characterized as a potential
geological repository. Check out EPA's Yucca Mountain
Information HomePage for more information.
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 nCi/g and co-mingled 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 percentage of non-DOE
MTRU is negligible. Approximately 55% of DOE's TRU waste is MTRU.
MTRU is currently being treated and stored at six DOE sites:
Hanford, (3,000 m3); INEL (38,000 m3); Los
Alamos National Laboratories, New Mexico (8,000 m3);
Rocky Flats, Colorado (1,500 m3); Oak Ridge National
Laboratories, Tennessee (1,500 m3); SRS (5,000
m3). DOE plans to dispose of 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
WIPP complies with EPA's radioactive waste disposal standards. DOE
must submit a "compliance application" to EPA showing how the WIPP
facility will meet these radioactive waste disposal standards. DOE
has submitted a petition to EPA's Office of Solid Waste
(which administers RCRA regulations) for a "no-migration" variance
for the WIPP MTRU. A "no-migration" variance is granted when the
hazardous waste is found to be permanently isolated from the
environment for as long as the waste remains hazardous waste. The
WIPP facility is scheduled to begin operation in the Spring of 1998,
subject to EPA approval of DOE's compliance application.
In DOE's 1995 Baseline Environmental Management Report it roughly
estimates that the life-cycle costs for HLW, TRU (including MTRU),
and LLMW are $34 billion, $13 billion, and $13 billion respectively
over a 75 year period. " Closing the circle
on the splitting of the Atom" is another DOE report on the
environmental legacy of nuclear weapons production in the United
States.
As mandated by the Federal
Facilities Compliance Act (FFCA), which was signed into law in
October 6, 1992, DOE has developed Site Treatment Plans to handle
its mixed wastes under the review of EPA or its authorized States.
These are being implemented by orders issued by EPA or the State
regulatory authority. DOE is also developing a Waste Management
Programmatic Environmental Impact Statement (WM PEIS) for managing
treatment, storage, and disposal of radioactive and hazardous waste.
This plan will provide environmental input for DOE's proposed action
of identifying future configurations for selecting waste management
facilities. It will take the cooperation of DOE, EPA, NRC, and the
States to address this legacy of the cold war. Proposed DOE
Treatment Options are available from the following DOE
INEL server.
URL:
http://www.epa.gov/radiation/mixed-waste/mw_pg3.htm Last Updated:
November 28, 2000
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