Appendix G
Acronyms and Definitions
A
Aluminum Spent Nuclear Fuel.
Irradiated fuel that contains uranium-aluminum matrix fuel elements and (or) is clad in aluminum.
Austenitic Stainless Steel.
Nickel-chromium stainless steel identified as 300 series.
C
Canyon.
Facility used to reprocess spent nuclear fuel, so named because on its long, narrow shape. There are two operating reprocessing facilities at Savannah River, the F Canyon and H Canyon.
CFR.
Code of Federal Regulations.
Chloride Volatility Treatment.
A process for treating aluminum spent fuel that involves the reaction of the spent fuel with chlorine or HCl gas at elevated temperatures to produce volatile chlorides, which are subsequently recovered by scrubbing and fractional distillation.
Cladding.
A thin metal covering on a fuel element comprised of alloys such as aluminum, zircalloy, or stainless steel.
Conventional Reprocessing.
A solvent extraction process for separating and recovering uranium and, if desired, plutonium from spent nuclear fuel.
Cost Comparison Point.
The estimated cost for each of the treatment options evaluated by the Task Team.
Cost of Time.
Operational costs of a facility that are unrelated to actual production activities, including management and administrative costs, costs of supporting workers in a stand-by mode, and other operational costs that are time related rather than production or throughput related.
Criticality Event.
A self-sustaining nuclear reaction like that which occurs in a nuclear reactor.
CRWMS.
Civilian Radioactive Waste Management System.
D
D&D.
Decontamination and Decommissioning.
Depleted Uranium.
Uranium that is depleted in uranium-235 relative to natural abundances.
Direct Co-Disposal Treatment.
A process for treating aluminum spent fuel that involves drying the fuel and placing it into a canister for shipment to the repository for loading into a repository container with other canisters of vitrified waste.
Disposable Canister.
A stainless steel canister whose primary purpose is to protect the spent fuel or the treated equivalent during interim storage, shipping, and handling operations.
Disposal Container.
A container consisting of corrosion-resistant metallic layers designed to hold a number of spent fuel assemblies or high-level waste glass logs for disposal in a repository. This container is expected to maintain its integrity for thousands of years.
Dissolve and Vitrify Treatment.
A process for treating aluminum spent fuel that involves dissolution of the fuel in acid along with depleted uranium to reduce the uranium-235 concentration to 20 percent or less by mass and vitrification of the resulting liquid waste stream.
DOE.
U.S. Department of Energy.
DOE-Savannah River.
U.S. Department of Energy, Savannah River Field Office and Westinghouse Savannah River Company staff.
DOE-Yucca Mountain.
U.S. Department of Energy, Office of Civilian Radioactive Waste Management and its management and operating contractor.
DRR.
Domestic Research Reactor.
DWPF.
Defense Waste Processing Facility, a facility located at Savannah River for vitrifying high-level waste from defense operations.
E
EIS.
Environmental Impact Statement.
Electrometallurgical Treatment.
A process for treating aluminum spent fuel that involves melting and electrorefining to separate aluminum, uranium, and fission products.
EM.
U.S. Department of Energy, Office of Environmental Management.
EPA.
U.S. Environmental Protection Agency.
F
Fissile Isotope.
An isotope that will fission in the presence of low-energy (thermal) neutrons, for example, uranium-235 and plutonium-239 (see, for example, A Guide to Nuclear Power Technology, John Wiley and Sons).
Fission.
A process involving the separation of the nucleus of an atom into two (and sometimes three) fragments, accompanied by the release of neutrons and energy.
Frit.
Powdered borosilicate glass used in the vitrification process.
FRR.
Foreign Research Reactor.
G
Gaseous Fission Products.
Isotopes produced by fission of uranium and plutonium that exist in a gaseous state at room temperature and pressure, for example, krypton and zenon.
Glass Material Oxidation and Dissolution Treatment.
A process for treating aluminum spent fuel that involves melting the spent fuel with depleted uranium, adding lead oxide to oxidize the metals, and then adding frit to make glass with a uranium-235 enrichment of 20 percent or less by mass.
GMOD.
Glass Material Oxidation and Dissolution Treatment.
H
HEU.
Highly Enriched Uranium, uranium that contains more than 20 percent uranium-235 by mass.
HFIR.
High Flux Isotope Reactor, a research reactor located at the Oak Ridge site in Tennessee.
HLW.
High-Level Waste, the liquid by-product of conventional reprocessing, which contains fission products and trace amounts of uranium and plutonium.
Hot Cell.
A physically isolated and heavily shielded space in which highly radioactive materials can be handled by remote control.
I
IAEA.
International Atomic Energy Agency.
INEEL.
Idaho National Engineering and Environmental Laboratory, formerly the Idaho National Engineering Laboratory (INEL).
L
LEU.
Low-Enriched Uranium, uranium that contains 20 percent or less uranium-235 by mass.
Life-Cycle Costs.
The total costs of designing, constructing, operating, and decontaminating and decommissioning a treatment or storage facility.
M
Melt and Dilute Treatment.
A process for treating aluminum spent fuel that involves melting the spent fuel along with depleted uranium to produce an alloy that has a uranium-235 enrichment of 20 percent or less by mass.
MGDS.
Mined Geological Disposal System.
MTHM.
Metric Tons Heavy Metal, the amount of heavy metal (uranium, thorium, and plutonium) present in fresh (unirradiated) fuel.
N
Neutron Poison.
A neutron absorbing material such as boron that can be incorporated into the spent fuel storage and shipping canister to reduce the likelihood of a criticality event.
NRC.
National Research Council.
O
OCRWM.
U.S. Department of Energy, Office of Civilian Radioactive Waste Management.
Off-Gas Treatment.
A process for capturing gaseous or volatile fission products that are released when spent fuel is melted.
OMB.
Office of Management and Budget.
P
PA.
Performance Assessment.
PEIS.
Programmatic Environmental Impact Statement.
P.I.
Principal Investigator.
P.L.
Public Law.
Plasma Arc Treatment.
A process for treating aluminum spent fuel that involves melting the fuel along with depleted uranium in a plasma arc furnace at high temperature to produce a vitreous ceramic with a uranium-235 enrichment of 20 percent or less by mass.
Press and Dilute Treatment.
A process for treating aluminum spent fuel that involves physically pressing the cut and sized spent fuel into sandwiches along with sheets of depleted uranium to produce
dimensionally uniform packages with composite uranium-235 enrichments of 20 percent or less by mass.
Processing and Co-Disposal Treatment.
A process for treating aluminum spent fuel that involves treating a portion of the aluminum spent fuel by conventional reprocessing and treating the remainder by direct co-disposal treatment.
Production Reactors.
Nuclear reactors used to produce plutonium or tritium for weapons.
R
RBOF.
Receiving Basin for Offsite Fuels.
Research Reactors.
Nuclear reactors used for research and development activities.
ROD.
Record of Decision.
S
SNF.
Spent Nuclear Fuel.
T
TSS.
Treatment, Storage, and Shipping Facility.
U
USNRC.
U.S. Nuclear Regulatory Commission.
V
Vitrification.
A process used to stabilize high-level waste that involves melting the waste in glass and solidifying the product in metal canisters.
W
WAC.
Waste Acceptance Criteria, the physical, chemical, and thermal characteristics that spent fuel, high-level waste, and associated disposable canisters must conform to for disposal in a repository.
Waste-Package Performance Criteria.
The physical, chemical, and thermal characteristics that a waste package containing spent fuel or its treated equivalent must meet to be acceptable for shipment to and emplacement in a repository container.
WSRC.
Westinghouse Savannah River Company.
