Radioactive Waste Streams: Waste Classification for Disposal
Radioactive Waste Streams:
Waste Classification for Disposal
Updated December 13, 2006
Specialist in Industrial Engineering and Infrastructure Policy
Resources, Science, and Industry Division
Radioactive Waste Streams:
An Overview of Waste Classification for Disposal
Radioactive waste is a byproduct of nuclear weapons production, commercial
nuclear power generation, and the naval reactor program. Waste byproducts also
result from radioisotopes used for scientific, medical, and industrial purposes. The
legislative definitions adopted for radioactive wastes, for the most part, refer to the
processes that generated the wastes. Thus, waste disposal policies have tended to
link the processes to uniquely tailored disposal solutions. Consequently, the origin
of the waste, rather than its radiologic characteristics, often determines its fate.
Plutonium and enriched uranium-235 were first produced by the Manhattan
Project during World War II. These materials were later defined by the Atomic
Energy Act of 1954 as special nuclear materials, along with other materials that the
former Atomic Energy Commission (AEC) determined were capable of releasing
energy through nuclear fission. Reprocessing of irradiated nuclear fuel to extract
special nuclear material generated highly radioactive liquid and solid byproducts.
The Nuclear Waste Policy Act of 1982 (NWPA) defined irradiated fuel as spent
nuclear fuel, and the byproducts as high-level waste. Uranium ore processing
technologically enhanced naturally occurring radioactive material and left behind
uranium mill tailings. The fabrication of nuclear weapons generated transuranic
waste. Both commercial and naval reactors continue to generate spent fuel. High-
level waste generation has ceased in the United States, as irradiated fuel is no longer
reprocessed. The routine operation and maintenance of nuclear reactors, however,
continues to generate low-level radioactive waste, as do medical procedures using
The NWPA provides for the permanent disposal of spent nuclear fuel and high-
level radioactive waste in a deep geologic repository. The repository is to be
constructed and operated by the Department of Energy (DOE) under the Nuclear
Regulatory Commission’s (NRC) licensing authority. Yucca Mountain, in Nevada,
is the candidate site for the nation’s first repository.
The NRC and the Environmental Protection Agency (EPA) share regulatory
authority for radioactive waste disposal. However, these regulatory agencies have
yet to adopt uniform radiation protection standards for disposal sites. The NRC’s
jurisdiction, however, does not extend to DOE’s management of defense-related
waste at DOE facilities other than Yucca Mountain.
Radioactive waste classification continues to raise issues for policymakers.
Most recently, DOE policy on managing the residue in high-level waste storage tanks
proved controversial enough that Congress amended the definition of high-level
waste. The disposition of waste with characteristics left undefined by statute can be
decided by an NRC administrative ruling. The case for low-activity waste promises
to provoke similar controversy. This report will be updated as new radioactive waste
classification issues arise.
Measurement of Radioactivity and Hazards of Radiation ..................2
Comparative Range of Radioactivity...................................4
Spent Nuclear Fuel.................................................6
High-Level Radioactive Waste......................................12
Waste Incidental to Reprocessing....................................13
Surplus Weapons-Usable Plutonium..................................16
Low-Level Radioactive Waste.......................................17
Provisions for State Disposal Compacts...........................21
Low-Level Waste Classification Tables...........................21
Mixed Low-Level Radioactive and Hazardous Waste.....................26
Technologically Enhanced Naturally Occurring Radioactive Material........27
Energy Policy Act Provisions for NORM..........................28
Uranium Mill Tailings ............................................30
Waste Disposal Policy Issues........................................31
List of Tables
Table 1. Contribution to Average Annual Exposures from Natural and Artificial
Table 2. Legislative and Regulatory Reference to Waste Definitions..........6
Table 3. Federal Site, Commercial Reactor Pool, and Independent
Spent Fuel Storage............................................10
Table 4. Physical Form and Characteristics of Low-Level Waste............19
Table A-1. Uranium Mill Tailing Site Volume and Activity................35
Table A-2. Low-Level Waste Commercial Disposal Site Volume
List of Figures
Figure 1. Comparison of Radioactive Wastes............................5
Figure 2. Federal Sites, Commercial Reactor Storage Pools, and Independent
Spent Fuel Storage Installations...................................9
Figure 3. Low-Level Waste Classification by Long-Lived Radionuclides.....22
Figure 4. Low-Level Waste Classification by Transuranic Radionuclides.....23
Figure 5. Low-Level Waste Classification by Short-Lived Radionuclides.....24
Figure 6. Low-Level Waste Classification by Mixed Long-Lived and
Radioactive Waste Streams: An Overview of
Waste Classification for Disposal
Radioactive waste is a byproduct of nuclear weapons production, commercial
nuclear power generation, and the naval reactor program. Waste byproducts also
result from radioisotopes used for scientific, medical, and industrial purposes. Waste
classification policies have tended to link the processes that generate the waste to
uniquely tailored disposal solutions. Consequently, the origin of the waste, rather
than its radiologic characteristics, often determines its fate.
Congress recently renewed its interest in radioactive waste classification when
a Department of Energy (DOE) order regarding the disposition of high-level waste
storage tank residue was legally challenged. As a result, Congress amended the1
statutory definition of high-level waste to exclude such residue. The classification
of other radioactive wastes continues to remain an aspect of disposal policy.
The Atomic Energy Act of 1946 (P.L. 79-585) defined fissionable materials to
include plutonium, uranium-235, and other materials that the Atomic Energy
Commission (AEC) determined to be capable of releasing substantial quantities of
energy through nuclear fission. Source material included any uranium, thorium, or
beryllium containing ore essential to producing fissionable material, and byproduct
material remaining after the fissionable material’s production. In the amended
Atomic Energy Act of 1954 (P.L. 83-703), the term special nuclear material
superseded fissionable material and included uranium enriched in isotope 233,
material the AEC determined to be special nuclear material, or any artificially2
As the exclusive producer, the AEC originally retained title to all fissionable
material for national security reasons. In the 1954 amended Act, Congress authorized
the AEC to license commercial reactors, and ease restrictions on private companies
using special nuclear material. Section 183 (Terms of Licenses) of the Act, however,
kept government title to all special nuclear material utilized or produced by the
licensed facilities in the United States. In 1964, the AEC was authorized to issue
commercial licenses to possess special nuclear material subject to specific licensing
conditions (P.L. 88-489).
1 Section 3116 (Defense Site Acceleration Completion), Ronald W. Reagan Defense
Authorization Act of FY2005 (P.L. 108-375).
2 Laws of 83rd Congress, 2nd Session, 1118-21.
Although the Atomic Energy Act referred to transuranic waste (material
contaminated with elements in atomic number greater than uranium), radioactive
waste was not defined by statute until the 1980s. High-level waste and spent nuclear
fuel were defined by the Nuclear Waste Policy Act (NWPA) of 1982 (42 U.S.C.
10101). Spent nuclear fuel is the highly radioactive fuel rods withdrawn from
nuclear reactors. High-level waste refers to the byproduct of reprocessing irradiated
fuel to remove plutonium and uranium. Low-level radioactive waste was defined by
the Low-Level Radioactive Waste Policy Act of 1980 (P.L. 95-573) as radioactive
material that is not high-level radioactive waste, spent nuclear fuel, or byproduct
material, and radioactive material that the Nuclear Regulatory Commission (NRC)
classifies as low-level radioactive waste consistent with existing law.
Measurement of Radioactivity and
Hazards of Radiation
The measurement of radioactivity and the hazards of radiation are, in
themselves, complex subjects. A discussion of radioactive waste would be
incomplete without reference to some basic terms and concepts.
Radioactive elements decay over time. The process of radioactive decay
transforms an atom to more a stable element through the release of radiation — alpha
particles (two protons and two neutrons), charged beta particles (positive or negative
electrons), or gamma rays (electromagnetic radiation).
Radioactivity is expressed in units of curies — the equivalent of 37 billion (37
x 109) atoms disintegrating per second. The rate of radioactive decay is expressed
as half-life — the time it takes for half the atoms in a given amount of radioactive
material to disintegrate. Radioactive elements with shorter half-lives therefore decay
The term for the absorption of radiation by living organisms is dose. The United
States uses the Roentgen Equivalent Man (rem) as the unit of equivalent dose in
humans. Rem relates the absorbed dose in human tissue to the effective biological
damage of the radiation.3 Not all radiation has the same biological effect, even for
the same amount of absorbed dose, as some forms of radiation are more efficient than
others in transferring their energy to living cells.
In 1977, the International Commission on Radiation Protection (ICRP)
concluded that an individual’s mortality risk factor from radiation-induced cancers
was about 1 x10-4 from an exposure of one rem dose (one lifetime chance out of
3 Rem is the product of the dose measured in units of rad (100 ergs/gram) multiplied by a
quality factor (Q) for each type of radiation; that is rem = rad x Q. For gamma rays, Q =
public should not receive annual exposures exceeding 500 millirem.4 The exposure
limit is made up of all sources of ionizing radiation that an individual might be
exposed to annually, which includes natural background and artificial radiation. An
individual in the United States receives an average annual effective dose equivalent
to 360 millirem, as shown in Table 1.
Table 1. Contribution to Average Annual Exposures
from Natural and Artificial Radioactive Sources
Natural - Radon200
Natural background radiation 100
Occupational related exposure0.9
Consumer products excluding tobacco13
Miscellaneous environmental sources0.06
Medical - diagnostic x rays39
Medical - nuclear medicine14
Average Annual Effective360
Source: National Council on Radiation Protection and Measurements, Report No. 9,
Ionizing Radiation Exposure of the Population of the United States, September 1, 1987.
The ICRP revised its conclusion on risk factors in 1990, and recommended that5
the annual limit for effective dose be reduced to 100 millirem. This limit is
equivalent to natural background radiation exclusive of radon. ICRP qualified the
recommendation with data showing that even at a continued exposure of 500
millirem, the change in age-specific mortality rate is very small — less than 4.5% for
females, less than 2.5% for males older than 50 years, and even less for males under
The radiation protection standards for NRC activities licensed under 10 C.F.R.6
Part 20 are based on a radiation dose limit of 100 millirem, excluding contributions
from background radiation and medical procedures. Unlike the NRC’s dose-based
approach to acceptable hazard level, the Environmental Protection Agency (EPA)
uses a risk-based approach that relies on the “linear, no-threshold” model of low-
level radiation effects. In the EPA model, risk is extrapolated as a straight line from
the high-dose exposure for Hiroshima and Nagasaki atomic bomb survivors down
to zero radiation exposure. Thus, the EPA model attributes risk to natural background
levels of radiation. For illustrative purposes, EPA considers a 1-in-10,000 risk that
4 Recommendations of the International Commission on Radiological Protection, January
5 International Commission on Radiation Protection, Recommendation of the International
Commission on Radiation Protection — Publication 60, Paragraph 161, 1990.
6 Part 20 — Standards for Protection Against Radiation.
an individual will develop cancer to be excessive, and has set a goal of 1-in-a-
million risk in cleanup of chemically contaminated sites. The Government
Accountability Office (GAO) has concluded that the low-level radiation protection
standards administered by EPA and NRC do not have a conclusive scientific basis,
as evidence of the effects of low-level radiation is lacking.7
Comparative Range of Radioactivity
The comparative range in radioactivity of various wastes and materials is
presented in Figure 1. Radioactivity is typically expressed in terms of “curies/
gram” for soil-like materials as well as radioactive materials that are homogeneous
in nature. However, because the inventories of some radioactive wastes are tracked
in terms of “curies/cubic- meter,” that unit of measure has been used here.
The lowest end of the scale (at the bottom of the figure) is represented by soils
of the United States — the source of natural background radiation. Radioactivity
ranging from 3 to 40 microcuries/cubic-meter may be attributed to potassium,
thorium and uranium in soils. Phosphogypsum mining waste is the byproduct of ore
processing that “technologically enhanced naturally occurring radioactive material”
(uranium) at higher levels than natural background (thus the term — TENORM), and
may range from 6.5 to 45 microcuries/cubic-meter. Uranium mill tailings (referred
to as 11e.(2) byproduct material) range from 97 to 750 microcuries/cubic-meter at
various sites (Appendix, Table A-1). On average, low-level waste ranges from 6.7
to 20 curies/cubic-meter based on the inventory of disposal facilities (Appendix,
Table A-2); a lower limit is left undefined by regulation, but an upper limit is set at
7,000 curies/cubic-meter based on specific constituents. Transuranic waste ranges
between from 47 to 147 curies/cubic-meter based on the Waste Isolation Pilot Plant
inventory. The vitrified high-level waste processed by the Savannah River Site
ranges from 6,700 to 250,000 curies/cubic-meter. Finally, spent fuel aged 10 to 100
years would range from 105,000 to 2.7 million curies/cubic-meter (Appendix, Table
A-3). These comparisons are for illustrative purposes only, as the radioactive
constituents among the examples are different.
7 U.S. Government Accounting Office, Radiation Standards — Scientific Basis Inconclusive,
and EPA and NRC Disagreement Continues (GAO/RCED-00-152), June 2000.
Figure 1. Comparison of Radioactive Wastes
Definitions of various radioactive wastes are summarized in Table 2 along with
applicable legislative provisions. More detailed descriptions of the wastes and the
processes that generate the wastes are provided further below.
Table 2. Legislative and Regulatory Reference
to Waste Definitions
Spent Nuclear Fuel (SNF) . . . withdrawn from a nuclearNuclear Waste Policy Act of 1982, 42
reactor following irradiationU.S.C. 10101
High-Level Waste (HLW) . . . highly radioactive materialNuclear Waste Policy Act of 1982,
from reprocessing spent nuclear fuel42 U.S.C. 10101
Radioactive Waste Incidental to Reprocessing . . .Defense Authorization Act for Fiscal
reclassified waste stream that would otherwise beYear 2005, P.L. 108-375
considered high-level due to its source or concentration
Transuranic Waste (TRU) . . . man-made elements aboveAtomic Energy Act of 1954, 42
atomic number 92U.S.C. 2014
Surplus Weapons-Usable PlutoniumNon-Proliferation and Export Control
Policy, PDD/NSC 13 1993
Low-Level Radioactive Waste (LLRW) . . . not high-levelLow-Level Radioactive Waste Policy
radioactive waste, spent nuclear fuel, transuranic waste, orAmendments Act of 1985, P. L. 99-
Class A, Class B, Class C Waste Licensing Requirements for Land
Greater than Class C (GTCC)Disposal of Radioactive Waste, 10
Mixed Low Level Radioactive and Hazardous Waste . . .Low-Level Radioactive Waste Policy
low-level radioactive waste under LLRWA and hazardousAct of 1985 — 42 U.S.C. 2021b &
chemicals regulated under RCRAResource Conservation and Recovery
Act of 1976 — 42 U.S.C. 6901
Uranium Mill Tailings . . . by-product material . . . Uranium Mill Tailings Radiation
naturally occurring radioactive material and uranium oreControl Act of 1978 — 42 U.S.C.
mill tailings 7901
Depleted Uranium Hexafluoride . . . the source material10 C.F.R. 40.4 — Domestic Licensing
uranium in which the isotope U-235 is less than 0.711of Source Material
percent of the total uranium present
Spent Nuclear Fuel
Currently, 104 commercial nuclear power reactors are licensed by the NRC to
operate in 31 states.8 These reactors are refueled on a frequency of 12 to 24 months.
A generic Westinghouse-designed 1,000-megawatt pressurized-water reactor (PWR)
operates with 100 metric tons of nuclear fuel. During refueling, approximately one-
third of the fuel (spent nuclear fuel) is replaced. The spent fuel is moved to a storage
pool adjacent to the reactor for thermal cooling and decay of short-lived
8 69 pressurized water reactors (PWR) and 35 boiling water reactors (BWR): U.S. Nuclear
Reactors, U.S. DOE, Energy Information Administration, at [http://www.eia.doe.gov/cneaf/
nuclear/page/nuc_react ors/reactsum.html ].
Due to the limited storage pool capacity at some commercial reactors, some
cooled spent fuel has been moved to dry storage casks. The NRC has licensed 30
independent spent fuel storage installations (ISFSI)for dry casks in 23 states.9 Fuel
debris from the 1979 Three Mile Island reactor accident has been moved to interim
storage at the Idaho National Laboratory (INL). General Electric Company (GE)
operates an independent spent fuel storage installation (Morris Operation) in Morris
Illinois. A group of eight electric utility companies has partnered as Private Fuel
Storage, LLC with the Skull Valley Band of Goshute Indians, and applied for an
NRC license to build and operate a temporary facility to store commercial spent
nuclear fuel on the Indian reservation in Skull Valley, Utah.
DOE spent fuel originated from nuclear weapons production, the naval reactor
program, and both domestic and foreign research reactor programs. DOE spent fuel
remains in interim storage at federal sites in Savannah River, South Carolina;
Hanford, Washington; INL; and Fort St. Vrain, Colorado.10
In contrast to commercial reactors, naval reactors can operate without refueling
for up to 20 years. 11 As of 2003, 103 naval reactors were in operation, and nearly as
many have been decommissioned from service. Approximately 65 metric tons heavy
metal (MTHM) of spent-fuel have been removed from the naval reactors. Until
1992, naval spent fuel had been reprocessed for weapons production, and since then
has been transferred to INL for interim storage.
The planned Yucca Mountain repository is scheduled to receive 63,000 MTHM
commercial spent nuclear fuel, and 2,333 MTHM of DOE spent-fuel.12 The NWPA
prohibits disposing of more than the equivalent of 70,000 MTHM in the first
repository until a second is constructed.
The Energy Information Administration reported an aggregate total 47,023.4
MTHM discharged from commercial rectors over the period of 1968 to 2002.13 Of
the total, 46,268 MTHM is stored at reactor sites, and the balance of 755.4 MTHM
is in stored away from reactor sites.
CRS obtained and compiled raw data from EIA on spent fuel discharged by
commercial reactor operators to the end of 2002, and data on spent fuel stored at the
9 U.S. NRC, 2004-2005 Information Digest, Figure 42 — Licensed Operating Independent
Spent Fuel Storage Installations.
10 U.S. DOE Office of Civilian Radioactive Waste Management, Appendix A, Final
Environmental Impact Statement for the Disposal of Spent Nuclear Fuel and High-Level
Radioactive Waste at Yucca Mountain, Nye County, Nevada (DOE/EIS-0250), February
11 U.S DOE and Department of the Navy, The United States Navy Nuclear Propulsion
Program, March 2003.
12 Appendix A — Final Environmental Impact Statement.
13 U.S. DOE Energy Information Administration, Spent Nuclear Fuel Data, Detailed
United States as of December 31, 2002, at [http://www.eia.doe.gov/cneaf/nuclear/spent_
DOE national laboratory and defense sites (as of 2003 year-end).14 A combined total
of 49,333 MTHM had been discharged by commercial- and defense-related activities
at the end of 2002. Commercial reactor storage pools accounted for 41,564 MTHM,
and ISFSIs accounted for 5,294 MTHM. The balance was made up by 2,475 MTHM
of federal spent fuel stored at national laboratories, defense sites, and university
research reactors.15 CRS’s figures differ from EIA’s in several respects: EIA
compiles only commercial spent fuel data, combines data on reactor storage pool and
dry storage at the reactor facility site, and identifies non-reactor site spent fuel as
“away from reactor site” storage.16 The data are geographically presented in Figure
At the end of 1998, EIA reported 38,418 MTHM of spent fuel discharged.17
Based on 47,023 MTHM discharged at the end of 2002, CRS estimates that
commercial reactor facilities discharge an average 2152 MTHM of spent fuel
annually. On that basis, CRS estimates 53,637 MTHM of spent fuel had been
discharged at the end of 2004.
14 U.S. DOE Energy Information Administration, Form RW-859, “Nuclear Fuel Data”
15 Idaho National Engineering and Environmental Laboratory INTEC Programs Division
16 Mostly General Electric’s Morris facility, and the Fort St. Vrain High Temperature Gas
Reactor facility in DOE caretaker status.
17 U.S. DOE Energy Information Administration, Prior Years 1998 Table, at [http://www.
eia.doe.gov/cneaf/nuclear/s pent_fuel/ussnfdata.html ].
Figure 2. Federal Sites, Commercial Reactor Storage Pools, and Independent Spent Fuel Storage Installations
Source: U.S. DOE National Laboratories as of 2003 year end, and U.S. DOE EIA Form RW-859 as of 2002 year end.
Note: Numbered labels refer to facilities in Table 3.
Table 3. Federal Site, Commercial Reactor Pool, and Independent Spent Fuel Storage
St T Assembly MTHM Facility St T Assembly MTHM
P1,517666.746. Shearon Harris Nuclear Power Plant NCP3,814964.5
rkansas Nuclear OneAKI552241.447. Cooper Nuclear Station NEP1,537278.6
wns Ferry Nuclear PlantALP6,6961,230.248. Fort Calhoun Nuclear StationNEP839305.0
ey Nuclear Plant ALP2,011903.849. Seabrook Nuclear StationNHP624287.2
alo Verde Nuclear Generating StationAZP2,7471,157.850. Hope Creek Generating StationNJP2,376431.5
iablo Canyon Power PlantCAP1,736760.951. Oyster Creek Generating StationNJP2,556455.9
E Vallecitos Nuclear Center CAI00.2I24447.6
umboldt Bay Power Plant CAP39028.952. Salem Nuclear Generating. StationNJP1,804832.7
Seco Nuclear Generating StaCAI493228.453. Sandia National LaboratoryNMF5030.3
iki/CRS-RL32163nofre Nuclear Generating Station CAP2,4901,013.354. Brookhaven National LaboratoryNYF400.0
g/w Fort St. Vrain Power StationCOF1,46414.7P2,460446.5
s.or55. JA Fitzpatrick Nuclear Power PlantNY Connecticut Yankee Atomic Power Co CTP1,019412.3I20437.2
ne Nuclear Power Station CTP4,5581,227.956. Indian Point Energy CenterNYP2,073903.6
://wiki Crystal River Nuclear Power Plant FLP824382.357. Nine Mile Point Nuclear StationNYP4,456801.6
http St. Lucie Nuclear Power Plant FLP2,278870.758. R E Ginna Nuclear Power PlantNYP967357.4
Turkey Point Station FLP1,862851.759. Davis-Besse Nuclear Power StationOHP749351.3
AW Vogtle, Jr. Electric Gen Plant GAP1,639720.8I7233.9
P5,019909.360. Perry Nuclear Power PlantOHP2,088378.4
EL Hatch Nuclear Plant GAI816151.261. Trojan Nuclear Power PlantORP780358.9
D Arnold Energy CenterIAP1,912347.962. Beaver Valley Power StationPAP1,456672.9
Idaho National Eng & Env LabIDF93,705300.263. Limerick Generating StationPAP4,601824.0
Argonne National Lab East ILF780.164. Peach Bottom Atomic Power StaPA P5,9051,062.7
Braidwood Generating Station ILP1,485628.7I1,020190.3
Byron Generating Station ILP1,786756.465. Susquehanna Steam Electric StationPAP4,240738.4
Clinton Power Station ILP1,580288.8I1,300238.5
P5,6981,009.266. Three Mile Island Nuclear StationPAP898416.1
Dresden Generating Station ILI1,155146.967. Catawba Nuclear StationSCP1,780782.4
St T Assembly MTHM Facility St T Assembly MTHM
General Electric Morris OpILI3,217674.3P344147.9
68. HB Robinson Steam Electric PlantSC LaSalle County Generating Station ILP4,106744.6I5624.1
uad Cities Generating StationILP6,1161,106.5P1,419665.8
69. Oconee Nuclear StationSC Zion Generating Station ILP2,2261,019.4I1,726800.4
Wolf Creek Generating StationKSP925427.370. Savannah River Defense SiteSCF9,65728.9
River Bend StationLAP2,148383.971. VC Summer Nuclear StationSCP812353.9
Waterford Generating StationLAP960396.472. Sequoyah Nuclear Power PlantTNP1,699782.6
Pilgrim Nuclear Station MAP2,274413.973. Watts Bar Nuclear PlantTNP297136.6
Yankee Rowe Nuclear Power StationMAI533127.174. Comanche Peak Steam Electric StationTXP1,273540.7
P1,348518.075. South Texas ProjectTXP1,254677.8
Calvert Cliffs Nuclear Power PlantMDI960368.1P1,410652.7
iki/CRS-RL3216376. North Anna Power StationVA Maine Yankee Atomic Power PlantMEI1,434542.3I480220.8
g/w Big Rock Point Nuclear PlantMII44157.9P794365.4
s.or77. Surry Power StationVA
leak D C Cook Nuclear PlantMIP2,198969.0I1,150524.2
Enrico Fermi Atomic Power PlantMIP1,708304.678. Vermont Yankee Generating StationVTP2,671488.4
://wiki P 649 260. 7 P 1, 904 333. 7
http Palisades Nuclear Power StationMI79. Columbia Generating StationWA
I 432 172. 4 I 340 61. 0
Monticello Nuclear Generating PlantMNP1,342236.180. Hanford Defense SiteWAF110,1402,128.9
P1,135410.381. Kewaunee Nuclear Power PlantWIP904347.6
Prairie Island Nuclear Gen. PlantMNI680262.382. La Crosse Nuclear Generating. StationWIP33338.0
Callaway Nuclear PlantMOP1,118479.083. Point Beach Nuclear PlantWIP1,353507.4
Grand Gulf Nuclear StationMSP3,160560.2I360144.1
Brunswick Steam Electric PlantNCP2,227477.484. University Research & Domestic Training ReactorsF4,8341.7
W B McGuire Nuclear StationNCP2,2321,001.1
y Type (T):
Commercial Reactor PoolP145,58941,564.1Commercial ISFSI I18,6305,294.6
National Lab & Defense Site StorageF220,4212,474.8Combined Total384,64049,333.4
High-Level Radioactive Waste
NWPA defines high-level waste as “liquid waste produced directly in
reprocessing and any solid material derived from such liquid waste that contains
fission products in sufficient concentrations,” and “other highly radioactive material”18
that NRC determines requires permanent isolation. Most of the United States’
high-level waste inventory was generated by DOE (and former AEC) nuclear
weapons programs at the Hanford, INL, and Savannah River Sites. A limited
quantity of high-level waste was generated by commercial spent fuel reprocessing at19
the West Valley Demonstration Project in New York. Over concern that
reprocessing contributed to the proliferation of nuclear weapons, President Carter
terminated federal support for commercial reprocessing in 1977. For further
information on reprocessing policy, refer to CRS Report RS22542, Nuclear Fuel
Reprocessing: U.S. Policy Development, by Anthony Andrews.
Weapons-production reactor fuel, and naval reactor spent fuel were processed
to remove special nuclear material (plutonium and enriched uranium). Reprocessing20
generated highly radioactive, acidic liquid wastes that generated heat. Weapons-
related spent fuel reprocessing stopped in 1992, ending high-level waste generation
in the United States. The wastes that were previously generated continue to be stored
at Hanford, INL, and Savannah River, where they will eventually be processed into
a more stable form for disposal in a deep geologic repository.
The Hanford Site generated approximately 53 million gallons of high-level
radioactive and chemical waste now stored in 177 underground carbon-steel tanks.21
Some strontium and cesium had been separated out and encapsulated as radioactive
source material, then commercially leased for various uses. The Savannah River
Site generated about 36 million gallons of high-level waste that it stored in 53
18 “Permanent isolation” is left undefined by the NWPA.
19 From 1966 to 1972, Nuclear Fuel Services operated a commercial nuclear fuel
reprocessing plant at the Western New York Nuclear Services Center under contract to the
State of New York. During the six years of operation, the plant processed approximately 640
metric tons of spent nuclear fuel, about three-fourths of which was provided by the AEC (60
percent of the total was from U. S. defense reactors). The plant generated approximately
2.3 million liters (600,000 gallons) of liquid high-level waste that was stored in underground
tanks. In 1972, nuclear fuel reprocessing operations were discontinued. The liquid high-
level radioactive waste produced during reprocessing was stored in underground steel tanks.
New York State Energy Research and Development Authority, at [http://www.nyserda.
org/ westval.html ].
20 U.S. DOE, Integrated Data Base Report — 1995: U.S. Spent Nuclear Fuel and
Radioactive Waste Inventories, Projections, and Characteristics, Rev. 12 (DOE/RW-0006),
21 U.S. DOE Hanford Site, Electricity, Water, and Roads for Hanford’s Future Vitrification
Plant Completed Ahead of Schedule and Under Budget, press release, September 18, 2001,
underground carbon-steel tanks.22 Both the Hanford and Savannah River Sites had
to neutralize the liquid’s acidity with caustic soda or sodium nitrate to condition it
for storage in the carbon-steel tanks. (The neutralization reaction formed a
precipitate which collected as a sludge on the tank bottom; see the discussion of
waste-incidental-to- reprocessing below.) Savannah River has constructed and begun
operating a defense-waste processing facility that converts high-level waste to a
vitrified (glass) waste-form. The vitrified waste is poured into canisters and stored
on site until eventual disposal in a deep geologic repository. A salt-stone byproduct
will be permanently disposed of on site. Hanford has plans for a similar processing
INL generated approximately 300,000 gallons of high-level waste through 1992
by reprocessing naval reactor spent fuel, and sodium-bearing waste from cleaning
contaminated facilities and equipment.23 The liquid waste had originally been stored
in 11 stainless steel underground tanks. All of the liquid high-level waste has been
removed from five of the 11 tanks and thermally converted to granular (calcine)
solids. Further treatment is planned, and INL is also planning a waste processing
facility similar to Savannah River’s vitrification plant.
West Valley’s high-level waste has been vitrified and removed from the site.
The vitrification process thermally converts waste materials into a borosilicate glass-
like substance that chemically bonds the radionuclides. The vitrification plant is
being decommissioned. The Hanford Site and INL are planning similar vitrification
High-level waste is also considered a mixed waste because of the chemically
hazardous substances it contains, which makes it subject to the environmental
regulations under the Resource Conservation and Recovery Act (RCRA).
Waste Incidental to Reprocessing
DOE policy in Order 435.1 refers to waste incidental to reprocessing in
reclassifying a waste stream that would otherwise be considered high-level due to its
source or concentration.24 DOE’s Implementation Guide to the Order states that
“DOE Manual 435.1-1 is not intended to create, or support the creation of, a new
waste type entitled incidental waste.” The waste stream typically results from
reprocessing spent fuel. DOE has determined that under its regulatory authority the
incidental-to-processing waste stream can be managed according to DOE
requirements for transuranic or low-level waste, if specific criteria are met.
22 U.S. DOE Savannah River Site, Spent Nuclear Fuel Program Fact Sheet, at [http://www.
srs.gov/ general/outreach/srs-cab/fuelfrm/facts1.htm] .
23 U.S. DOE Idaho National Laboratory/ Idaho Nuclear Technology and Engineering Center
— Cleanup Status, at [http://www.inel.gov/ environment/intec/].
24 U.S. DOE, M 435.1-1 Radioactive Waste Management Manual of 7-09-99, and G 435.1-
The DOE evaluation process for managing spent-fuel reprocessing wastes
considers whether (1) the “wastes are the result of reprocessing plant operations such
as contaminated job wastes including laboratory items such as clothing, tools and
equipment,”25 and (2) key radionuclides have been removed in order to permit
downgrading the classification to either low-level waste or transuranic waste.
Evaluation process wastes include large volumes of low-activity liquid wastes
(separated from high-level waste streams), a grout or salt-stone solid form, and high-
level waste residues remaining in storage tanks. DOE’s evaluation process at the
Savannah River Site resulted in capping the residue left in high-level waste storage
tanks with cement grout.
Public comments on the draft of Order 435.1 expressed the concern that
potentially applicable laws do not define or recognize the principle of “incidental
waste,” or exempt high-level waste that is “incidental” to DOE waste management
activities from potential NRC licensing authority.26 In 2003, the Natural Resources
Defense Council (NRDC) challenged DOE’s evaluation process for Savannah River
as scientifically indefensible, since no mixing occurred to dilute the residue’s
activity when capping it with grout.27 DOE countered that through the waste-
incidental-to-reprocessing requirements of Order 435.1, key radionuclides have been
removed from the tanks, and the stabilized residual waste does not exceed Class C
low-level radioactive waste restrictions for shallow land burial.28 Removing the
residual waste would be costly and expose workers to radiologic risks, according to
In NRDC v. Abraham, the Federal District Court in Idaho ruled in 2003 that
DOE violated the NWPA by managing wastes through the evaluation process in
Order 435.1.29 The Energy Secretary later asked the Congress for legislation
clarifying DOE authority in determinations on waste-incidental-to-reprocessing at
Hanford, Savannah River, and INL.30 On November 5, 2004, the U.S. Court of
Appeals for the Ninth Circuit vacated the district court’s judgment and remanded the
case with a direction to dismiss the action.31
Section 3116 (Defense Site Acceleration Completion) in the Ronald W. Reagan
Defense Authorization Act of FY2005 (P.L. 108-375) specified that the definition of
25 Notice of Proposed Rulemaking (34 FR 8712) for Appendix D 10 C.F.R. 50.
26 U.S. DOE Office of Environmental Management, Summary of Public Comments on DOE
Order 435.1, Radioactive Waste Management, at [http://web.em.doe.gov/em30/pubsum16.
27 Letter from Natural Resources Defense Council to the Honorable J. Dennis Hastert,
August 19, 2003.
28 Second Declaration of Jessie Roberson in NRDC v. Abraham, 271 F. Supp. 2nd 1260 (D.
29 NRDC v. Abraham, 271 F. Supp. 2nd 1260 (D. Id. 2003).
30 “DOE seeks nuclear waste clarification to reaffirm HLW disposal strategy,” Nuclear
Fuel, The McGraw-Hill Companies, August 19, 2003.
31 No. 03-35711 United States Court of Appeals for the Ninth Circuit 2004 U.S.
the term “high-level radioactive waste” excludes radioactive waste from reprocessed
spent fuel if (1) the Energy Secretary in consultation with the NRC determines the
waste has had highly radioactive radionuclides removed to the maximum extent
practical, and (2) the waste does not exceed concentration limits for Class C low-
level waste. As a result of the Act, NRC expects to review an increased number of
waste determinations. As guidance to its staff, NRC developed a draft Standard
Review Plan (NUREG-1854).32 Section 3117 of the Act (Treatment of Waste
Material) authorizes $350 million for DOE’s High Level Waste Proposal to
accelerate the cleanup schedule for the Hanford, Savannah River, and INL. For
further information on this subject, refer to CRS Report RS21988, Radioactive Tank
Waste from the Past Production of Nuclear Weapons: Background and Issues for
Congress, by David M. Bearden and Anthony Andrews.
The Atomic Energy Act (42 U.S.C. 2014) defines transuranic (TRU) waste as
material contaminated with elements having atomic numbers greater than uranium
(92 protons) in concentrations greater than 10 nanocuries/gram. The DOE (with
other federal agencies) revised the minimum radioactivity defining transuranic waste
from 10 nanocuries/gram to greater than 100 nanocuries/gram in 1984.
Transuranic elements are artificially created in a reactor by irradiating uranium.
These elements include neptunium, plutonium, americium, and curium. Many emit
alpha particles and have long half-lives.33 Americium has commercial use in smoke
detectors, and plutonium produces fission energy in commercial power reactors.
Transuranic waste is generated almost entirely by DOE (and former AEC)
defense-related weapons programs. The waste stream results from reprocessing
irradiated fuel to remove plutonium-239 or other transuranic elements, and from
fabricating nuclear weapons and plutonium-bearing reactor fuel. The waste may
consist of plutonium-contaminated debris (such as worker clothing, tools, and
equipment), sludge or liquid from reprocessing, or cuttings and scraps from
In 1970, the former AEC determined that the long half-life and alpha emissions
associated with transuranic waste posed special disposal problems. This prompted
the decision to stop the practice of burying TRU waste in shallow landfills as a low-
32 U.S. NRC, Standard Review Plan for Activities Related to U.S. Department of Energy
Waste Determinations — Draft Report For Interim Use and Comment (NUREG-1854), May
33 Arjun Makhijani and Scott Saleska, High-level Dollars, Low-Level Sense, The Apex
Press, New York, 1992.
34 U.S. DOE, Integrated Data Base Report-1995: U.S. Spent Nuclear Fuel and Radioactive
Waste Inventories, Projections, and Characteristics (DOE/RW-0006, Rev.12), December,
DOE distinguishes “retrievably stored” transuranic waste from “newly
generated” waste. Waste buried prior to 1970 is considered irretrievable and will
remain buried in place. Since 1970, transuranic waste has been packaged (e.g., metal
drums, wood or metal boxes) and retrievably stored in above-ground facilities such
as earth-mounded berms, concrete culverts, buildings, and outdoor storage pads.
Waste that has been retrieved or will be retrieved, and then repackaged for
transportation and disposal, is classed as newly generated waste.35
The Department of Energy National Security and Military Applications of
Nuclear Energy Authorization Act of 1980 (P.L. 96-164) directed the Energy
Secretary to consult and cooperate with New Mexico in demonstrating the safe
disposal of defense radioactive wastes. The Waste Isolation Pilot Plant Land
Withdrawal Act (P.L. 102-579 as amended by P.L. 104-211) limited disposal
acceptance to transuranic waste with a half-life greater than 20 years and radioactivity
greater than 100 nanocuries/gram. The WIPP Act further defined transuranic waste
in terms of “contact-handled transuranic waste” having a surface dose less than 200
millirem per hour, and “remote-handled transuranic waste” having a surface dose rate
greater than 200 millirem/hour. The WIPP facility (near Carlsbad, New Mexico)
began accepting transuranic waste in 1999 but was restricted by the New Mexico
Environment Department to accepting contact-handled waste only. In October 2006,
New Mexico revised WIPP’s permit to allow remote-handled waste.
The Resource Conservation and Recovery Act of 1976 (42 U.S.C. 6901)
imposed additional disposal requirements on transuranic waste mixed with hazardous
constituents. Mixed radioactive and hazardous waste is a separate classification
discussed further below.
The Energy and Water Development Appropriations Act for 2005 (P.L. 108-
447) and appropriation acts for some prior years precluded the WIPP facility from
disposing of transuranic waste containing plutonium in excess of 20%, as determined
Surplus Weapons-Usable Plutonium
The Atomic Energy defined “special nuclear material” as plutonium, uranium
enriched in isotopes 233 or 235, and any other material the NRC determined as
special nuclear material. Special nuclear material is important in weapons programs
and as such has strict licensing and handling controls. Under President Clinton’s
35 The National Academies Board on Radioactive Waste Management, Characterization of
Remote-Handled Transuranic Waste for the Waste Isolation Pilot Plant, Interim Report,
National Academy Press, Washington, D.C., 2001.
plutonium was declared surplus to national security needs.36 DOE plans to use
surplus plutonium in mixed oxide fuel for commercial power reactors.37 Plutonium
not suitable for mixed oxide fuel fabrication is destined for repository disposal. The
special facility constructed to reprocess the surplus would generate transuranic waste
and low-level radioactive waste streams. Spent mixed oxide fuel would be disposed
of in the same manner as conventional commercial spent fuel in an NRC-licensed
deep geologic repository.
Low-Level Radioactive Waste
The Low-Level Radioactive Waste Policy of 1980 (P.L. 96-573) defined “low-
level radioactive waste” as radioactive material that is not high-level radioactive
waste, spent nuclear fuel, or byproduct material, and radioactive material that the
Nuclear Regulatory Commission (NRC) classifies as low-level radioactive waste
consistent with existing law. Low-level waste is classified as A, B, C, or Greater
than Class C in 10 C.F.R. 61.55 — Waste Classification. These classes are described
further below. Commercial low-level waste is disposed of in facilities licensed under
NRC regulation, or NRC-compatible regulations of “agreement states.”
Low-level radioactive waste is generated by nuclear power plants,
manufacturing and other industries, medical institutions, universities, and
government activities. Much of the nuclear power plant waste comes from processes
that control radio-contaminants in reactor cooling water. These processes produce
wet wastes such as filter sludge, ion-exchange resins, evaporator bottoms, and dry
wastes. Institutions such as hospitals, medical schools, research facilities, and
universities generate wastes of significantly differing characteristics. Industrial
generators produce and distribute radionuclides, and use radioisotopes for
instruments and manufacturing processes. The General Accounting Office (now
Government Accountability Office) reported that of the 12 million cubic feet of low-
level waste disposed of in 2003, 99% constituted Class A.38
The NRC classifies low-level waste using two tables: one for long-lived
radionuclides, and one for short-lived. Long-lived and short-lived refer to the length
of time for radioactive decay. For regulatory purposes, the dividing line between
short-lived and long-lived is a half-life of 100 years. The radionuclides included as
long-lived are: carbon-14, nickel-59, niobium-94, technetium-99, iodine-129,
plutonium-241, and curium-242. The group “alpha emitting transuranic nuclides with
half-lives greater than 5 years” is included in the long-lived table, as various isotopes
of the group may have half-lives in the range of hundreds-of-thousand of years. The
short-lived radionuclide table includes tritium (hydrogen-3), cobalt-60, nickel-63,
36 U.S. DOE Office of Fissile Materials Disposition, Surplus Plutonium Disposition Final
Environmental Impact Statement (TIC:246358), 1999.
37 U.S. DOE, Record of Decision for the Surplus Plutonium Final Environmental Impact
Statement, 65 FR 1608; January 11, 2000.
38 U.S. GAO, Low-Level Radioactive Waste — Disposal Availability Adequate in the Short
Term, but Oversight Needed to Identify Any Future Shortfalls (GAO-04-604), June 2004.
strontium-90, and cesium-137. A group of unspecified “nuclides with half-lives less
than 5 years” is included as short-lived.
Low-level waste generated by nuclear power plants results from the fission of
uranium fuel, or the activation of the reactor components from neutrons released
during fission. Trace amounts of uranium left on fuel rod surfaces during
manufacturing are partly responsible for the fission products in the reactor cooling
water.39 Tritium (H-3) occasionally results from uranium fission, and from reactor
cooling water using boron as a soluble control absorber.40 The radionuclides carbon-
14, nickel-53, nickel-59, and niobium-94 are created when stainless steel reactor
components absorb neutrons. The radionuclides strontium-90, technetium-99, and
cesium-137 are fission products of irradiated uranium fuel. The transuranic
radionuclides are neutron-activation products of irradiated uranium fuel. Iodine-129
is found in radioactive wastes from defense-related government facilities and nuclear
fuel cycle facilities; if released into the environment, its water solubility allows its
uptake by humans, where it concentrates in the thyroid gland.41
Some of the short-lived radionuclides have specific industrial or institutional
applications. These include cobalt-60, strontium-90, and cesium-137. Cobalt-60 is
used in sealed sources for cancer radiotherapy and sterilization of medical products;
its intense emission of high-energy gamma radiation makes it an external hazard, as
well as an internal hazard when ingested. Strontium-90 is used in sealed sources for
cancer radiotherapy, in luminous signs, in nuclear batteries, and in industrial gauging.
Due to strontium’s chemical similarity to calcium, it can readily be taken up by
plants and animals, and is introduced into the human food supply through milk.
Cesium-137 also is used in sealed sources for cancer radiotherapy, and due to its
similarity to potassium can be taken up by living organisms.
Low-level waste classification ultimately determines whether waste is
acceptable for shallow land burial in an NRC- or state-licensed facility. The four
waste classes identified by 10 C.F.R. Section 61.55 on the basis of radionuclide
concentration limits are:
!Class A: waste containing the lowest concentration of short-lived
and long-lived radionuclides. Examples include personal protective
clothing, instruments, tools, and some medical wastes. Also, waste
containing any other radionuclides left unspecified by 10 C.F.R.
!Class B: an intermediate waste classification that primarily applies
to waste containing either short-lived radionuclides exclusively, or
a mixture of short-lived and long-lived radionuclides in which the
39 U.S. DOE, Appendix A, Final Environmental Impact Statement.
40 Raymond, L. Murray, Chapter 16 of Understanding Radioactive Waste, Battelle Press,
41 U.S. EPA, Facts about Iodine, at [http://www.epa.gov/superfund/resources/radiation/
long-lived concentration is less than 10% of the Class C
concentration limit for long-lived radionuclides.
!Class C: wastes containing long-lived or short-lived radionuclides
(or mixtures of both) at the highest concentration limit suitable for
shallow land burial. Examples include ion exchange resins and filter
materials used to treat reactor cooling water, and activated metals
(metal exposed to a neutron flux — irradiation — that creates a
radioactive isotope from the original metal).
!Greater than Class C (GTCC): waste generally not acceptable for
near-surface disposal. Greater than Class C wastes from nuclear
power plants include irradiated metal components from reactors such
as core shrouds, support plates, and core barrels, as well as filters
and resins from reactor operations and decommissioning.
The physical form, characteristics, and waste stability requirements are summarized
in Table 4.
Table 4. Physical Form and Characteristics of Low-Level Waste
Class AClass BClass CGreater thanClass C
FormTrash, soil, rubble,ReactorSame as Class BReactor
depleted uranium,components, sealedbut higher incomponents and
mildlyradioactive sources,radioactivity.filter resins from
contaminatedfilters and resinsreactor
equipment andfrom nuclear powerdecommissioning.
Specific activitynear background to3 0.04 to 700 Ci/m3 44 to 7,000 Ci/m3Greater than Class
Maximum waste 100-year decay to 100-year decay to 100-year decayUnspecified by
concentrationacceptable hazardacceptable hazardexceeds acceptableregulation.
basis level* to anlevel* to anhazard level* to an
intruder intruder. intruder.
by deeper disposal
Waste containersNo specialMust be designed toMust remain stable(Not applicable)
provisions, if wastebe stable for 300for 300 years.
is buried in ayears.
Special DisposalWaste stabilization(Not applicable)Barriers toThough generally
Provisionsrequired if buriedintrusion requirednot acceptable for
with Class B or Cthat must remainnear-surface
waste.effective for 500disposal, regulation
years where siteallows for disposal
conditions preventin near-surface
deeper disposal. facility if
approved by NRC,
or other wise must
be disposed of in a
* Acceptable hazard level to an intruder is based on maximum annual dose equivalent of 500 millirem (mrem) to
the whole body of any member of the public — Sec. 61.42, and draft Generic Environmental Impact Statement for
Part 61, NUREG-0782. Acceptable hazard level to the general population is based on maximum dose equivalent of
25 mrem to whole body, 75 millirems to thyroid, and 25 millirems to any organ of any member of the public.
Class A, B, and C wastes are candidates for near-surface disposal. The concept
for near-surface disposal is: a system composed of the waste form, a trenched
excavation, engineered barriers, and natural site characteristics. Through complex
computer models, the licensee must demonstrate that the site and engineered features
comply with the performance objectives in 10 C.F.R. Part 61. Generally Class A
and B wastes are buried no greater than 30 meters (~100 feet). Class C waste must
be buried at a greater depth to prevent an intruder from disturbing the waste after
institutional controls have lapsed. The operation of a disposal facility was originally
foreseen to last 20 to 40 years, after which it would be closed for stabilization period
of 1 to 2 years, observed and maintained for 5 to 15 years, then transferred to active
institutional control for 100 years.42 At the time of licensing, funds had to be
guaranteed by the state or licensee for the facility’s long term care after closure. At
present, no disposal facility exists for Greater than Class C Waste, though the DOE
is in the initial phase of a process to identify disposal options.43
The Senate Committee on Energy and Natural Resources conducted a hearing
in September 2004 to consider the potential shortage of low-level waste disposal
sites.44 The GAO had concluded in a 2004 report that no shortfall in disposal
capacity appeared imminent, although the national low-level waste database that
would be used to estimate the adequacy of future capacity was inaccurate.45 The
GAO recommended that the DOE stop reporting the database information, and added
42 U.S. NRC, Final Environmental Impact Statement on 10 CFR Part 61 “Licensing
Requirements for Land Disposal of Radioactive Waste (NURGEG-0945), November 1982.
43 “DOE begins looking at options for disposal of GTCC radwaste,” Nuclear Fuels, October
44 S. Hrg. 108-756, September 30, 2004.
45 U.S. GAO, Low-Level Radioactive Waste — Disposal Availability Adequate in the Short
Term, but Oversight Needed to Identify Any Future Shortfalls (GAO-04-604), June 2004.
that Congress may wish to consider directing the Nuclear Regulatory Commission
to report when the disposal capacity situation changes enough to warrant
Provisions for State Disposal Compacts
In enacting the Low-Level Radioactive Waste Policy Act of 1980, Congress also
established the policy that each state take responsibility for disposing of low-level
radioactive waste generated within its borders. To accomplish this, states may enter
into compacts. Section 102 of the 1986 amendments to the Act provided that each
state, either by itself or in cooperation with other states, be responsible for disposing
of low-level radioactive wastes generated within the state.
Low-Level Waste Classification Tables
The NRC created two tables in 10 C.F.R 61.55 for classifying low-level waste
on the basis of radionuclide concentration limits. Table 1 of the regulation applies to
long-lived radionuclides, and Table 2 applies to short-lived ( included as Figures A-1
and A-2 in the Appendix of this report). The concentration limits are expressed in
units of “curies/cubic meter” or “nanocuries/gram” (the latter unit applying
exclusively to the alpha-emitting transuranic radionuclides). Figures 3 through 6
represent an illustrative guide to interpreting Tables 1 and 2; they are not intended,
however, for actual waste classification purposes. The figures break down Tables 1
and 2 by long-lived, transuranic, short-lived and mixed long- and short-lived
radionuclides. In the case of mixed radionuclides, the “sum-of-the-fractions” rule
must be applied.
Sum-of-the-Fractions Rule. Waste containing a mixture of radionuclides must
be classified by applying the sum-of-the fractions rule. In the case of short-lived
radionuclides — for each radionuclide in the mixture, calculate the fraction:
then calculate the fractions’ sum. If the sum-of-the-fractions is less than 1, the waste
class is Class A. If the sum of the fractions is greater than 1, recompute each fraction
using the upper concentration limits. If the fraction sum is less than 1, the waste is
Class C; if greater than 1 then it is Greater than Class C. In the case of long-lived
radionuclides, sum the fractions of each radionuclide concentration divided by the
Column 1 concentration limits. If the resulting fraction sum is less than 1, the waste
is Class A. If the fraction sum is greater than 1, recompute the fractions by applying
the Column 2 concentration limits. If the sum is less than 1, the waste is Class B. If
the sum is greater than 1, recompute again using the Column 3 limits. For example,
consider a waste containing concentrations of long-lived radionuclides Sr-90 at 50
Ci/m3 and Cs-137 at 22 Ci/m3. Since the concentrations each exceed the values in
Column 1 (0.04 and 1.0 respectively) of Chart 3 (Table 2 of Section 61.55), they
must be compared to the concentration limits of Column 2. For Sr-90, the fraction
the fractions (0.33 + 0.5) equals 0.83. Since the sum is less than 1.0, the waste is
Figure 3. Low-Level Waste Classification by Long-Lived
Figure 4. Low-Level Waste Classification by Transuranic
Figure 5. Low-Level Waste Classification by Short-Lived
Figure 6. Low-Level Waste Classification by Mixed Long-Lived and
Mixed Low-Level Radioactive and Hazardous Waste
Mixed waste contains both concentrations of radioactive materials that satisfy
the definition of low-level radioactive waste in the Low-Level Radioactive Waste
Policy Act, and hazardous chemicals regulated under the Resource Conservation and
Recovery Act (RCRA, 42 U.S.C. 6901). In general, facilities that manage mixed
waste are subject to RCRA Subtitle C (Hazardous Waste) requirements for hazardous
waste implemented by EPA (40 C.F.R. 124 and 260-270) or to comparable
regulations implemented by states or territories that are authorized to implement
RCRA mixed waste authority. The RCRA Subtitle C program was primarily
developed for the states’ implementation with oversight by EPA.
Naturally occurring source material uranium contains uranium isotopes in the
approximate proportions of: U-238 (99.3%), U-235 (0.7%), and U-234 (trace
amount) by weight. Source material uranium is radioactive, U-235 contributing 2.2%
of the activity, U-238 48.6%, and U-234 49.2% .46 Depleted uranium is defined in
10 CFR 40.4 (Domestic Licensing of Source Material) as “the source material
uranium in which the isotope U-235 is less than 0.711 % of the total uranium
present.” It is a mixture of isotopes U-234, U-235, and U-238 having an activity less
than that of natural uranium.47 Most of the DOE depleted uranium hexafluoride
inventory has between 0.2% and 0.4% U-235 by weight.48
The former AEC began operating uranium enrichment plants in 1945 to produce
U-235 enriched fuel for national defense and civilian nuclear reactors. Most
commercial light-water reactors use uranium enriched 2%-5% with U-235.49 As part
of that enrichment process, uranium ore was converted to uranium hexafluoride
(UF6) gas to facilitate U-235’s separation, depleting the source material uranium of
its U-235 isotope. DOE’s inventory of depleted uranium hexafluoride (DUF6) is
approximately 700,000 metric tons. The DUF6 is stored in metal cylinders at the
three enrichment plant sites: Paducah, KY; Portsmouth, OH; and Oak Ridge, TN.
As part of DOE’s DUF6 Management Program,50 Oak Ridge National
Laboratory (ORNL) conducted an assessment of converting the DUF6 to one of four
stable forms: metallic (DU), tetrafluoride (DUF4), dioxide (DUO2) and triuranium
46 U.S. NRC, Natural Uranium, at [http://www.nrc.gov/reading-rm/basic-ref/glossary/
47 ANSI N7.2-1963 definition.
48 U.S. DOE, Office of Environmental Management Depleted Uranium Hexafluoride
Management Program, Overview of Depleted Uranium Hexafluoride Management Program,
49 U.S. DOE National Nuclear Security Administration, Nuclear Terms Handbook, 2001.
50 U.S. DOE, Depleted UF6 Management, at [http://web.ead.anl.gov/uranium/mgmtuses/
octaoxide (DU3O8).51 ORNL considers the characteristics of the four forms suitable
for disposal as low-level radioactive waste. The DU metal form has commercial and
military uses (aircraft counterweights, shielding, armor, and munitions).
DOE has considered the environmental impacts, benefits, costs, and institutional
and programmatic needs associated with managing its DUF6 inventory. In the 1999
Record of Decision for Long Term Management and Use of Depleted Uranium
Hexafluoride,52 DOE decided to convert the DUF6 to depleted uranium oxide,
depleted uranium metal, or a combination of both. The depleted uranium oxide
would be stored for potential future uses or disposal as necessary. Conversion to
depleted uranium metal would be performed only when uses for the converted
material were identified. DOE stated that it did not believe that long-term storage as
depleted uranium metal and disposal as depleted uranium metal were reasonable
alternatives. DOE has selected Uranium Disposition Services to design, build and
operate facilities in Paducah and Portsmouth to convert the DUF6. DOE has
effectively declared DUF6 a resource in the record of decision, anticipating its
conversion to non-reactive depleted uranium oxide. Making the material nonreactive
is intended to eliminate the RCRA criteria that otherwise would place it in a Mixed
Technologically Enhanced Naturally Occurring
Technologically Enhanced Naturally Occurring Radioactive Material
(TENORM) is a byproduct of processing mineral ores containing naturally occurring
radionuclides. These include uranium, phosphate, aluminum, copper, gold, silver,
titanium, zircon and rare earth ores.53 The ore beneficiation process concentrates the
radionuclides above their naturally occurring concentrations. Some TENORM may
be found in certain consumer products, as well as fly ash from coal-fired power
plants. Activities such as treating drinking water also produce TENORM. Surface
and groundwater reservoirs may contain small amounts of naturally occurring
radionuclides (uranium, radium, thorium, and potassium; i.e., NORM). In areas
where concentrations of radium are high in underlying bedrock, groundwater
typically has relatively high radium content. Water treatment/filtration plants may
remove and concentrate NORM in a plant’s filters, tanks, and pipes. The result is
technologically concentrated NORM (thus TENORM) in the form of filtrate and
tank/pipe scale. Radium-226, a decay product of uranium and thorium soluble in
water, is a particular concern because of the radiologic threat it poses. Public
exposure to TENORM is subject to federal regulatory control.
51 Oak Ridge National Laboratory, Assessment of Preferred Depleted Uranium Disposal
Forms (ORNL/TM-2006/161) June 2000.
52 U.S. DOE, DUF6 Programmatic EIS, at [http://web.ead.anl.gov/uranium/documents/
53 U.S. EPA, TENORM Sources, at [http://www.epa.gov/radiation/tenorm/sources.htm#
At Congress’s request in 1997, the EPA arranged for the National Academy of
Sciences (NAS) to study the basis for EPA’s regulatory guidance on naturally
occurring radioactive material. The NAS study defined technologically enhanced
radioactive material (TENORM) as “any naturally occurring material not subject to
regulation under the Atomic Energy Act whose radionuclide concentrations or
potential for human exposure have been increased above levels encountered in the
natural state by human activities.” The NAS completed its study in 1999.54 The most
important radionuclides identified by the study include the long-lived naturally
occurring isotopes of radium, thorium, uranium, and their radiologically important
decay products. Radium is of particular concern because it decays to form
radioactive radon gas, a carcinogen contributing to lung cancer. NAS noted that
federal regulation of TENORM is fragmentary. Neither the EPA nor any other
federal agency with responsibility for regulating radiation exposure has developed
standards applicable to all exposure situations that involve naturally occurring
The EPA submitted its own report on implementing the NAS recommendations
to Congress the following year, along with plans to revise its TENORM guidance
documents.55 According to its website, the EPA has used its authority under a
number of existing environmental laws to regulate some sources of TENORM,
including the Clean Air Act, the Clean Water Act, the Safe Drinking Water Act, and
the Comprehensive Environmental Response, Compensation, and Liability Act
Energy Policy Act Provisions for NORM
The Energy Policy Act of 200557 contains a provision in Section 651 that
amends the Atomic Energy Act’s section 11(e) definition of “byproduct material” to
exclude “any discrete source of naturally occurring radioactive material [NORM],
other than source material” that the NRC, in consultation with the EPA, Department
of Energy, and Department of Homeland Security, determines would pose a threat
similar to the threat posed by a discrete source of radium-226. The Energy Policy
Act also made clear that byproduct material as defined in paragraphs (3) and (4) of
section 11(e) is not to be considered low-level radioactive waste for the purpose of
disposal under the Low-Level Radioactive Waste Policy Act and “carrying out a
compact” under the authorization of 42 U.S.C. sections 2021(b) et seq.58 ( permitting
54 National Research Council Committee on Evaluation of EPA Guidelines for Exposure
to Naturally Occurring Radioactive Materials, Evaluation of Guidelines for Exposures to
Technologically Enhanced Naturally Occurring Radioactive Materials, The National
Academies Press, Washington, D.C., 1999.
55 U.S. EPA, Evaluation of EPA’s Guidelines for Technologically Enhanced Naturally
Occurring Radioactive Materials (TENORM) — Report to Congress (EPA 402-R-00-01)
57 P.L. 109-58, 109th Cong., 1st Sess., 119 Stat. 594 (2005).
58 P.L. 109-58, § 65, 109th Cong., 1st Sess., 119 Stat. 807(2005).
NRC agreements with states to discontinue its regulatory authority over byproduct,
source, and special nuclear materials.)
The Nuclear Regulatory Commission (NRC) proposes to amend its regulations
to include jurisdiction over certain radium sources, accelerator-produced radioactive
materials (referred to as NARM).59 The proposed rule does not suggest any discrete
source of NARM nor criteria for making such a determination. It does note that
EPAct gives the NRC authority over discrete sources of radium-226 but not over
diffuse sources of radium-226 as it occurs in nature or over other processes where
radium-226 may be unintentionally concentrated.60 The specific example of
“residuals from treatment of water to meet drinking water standards” is given as a
Recently, the Rocky Mountain Low-Level Radioactive Waste Compact’s
authority to dispose of NORM and TENORM has been called into question over the
assertion that its jurisdiction violates the Commerce Clause of the U.S. Constitution.
Congress gave its consent to the Rocky Mountain Low-Level Radioactive Waste
Compact, consisting originally of the states of Arizona, Colorado, Nevada, New
Mexico, Utah, and Wyoming.61 Arizona, Utah, and Wyoming later withdrew from
the Compact, leaving Colorado, Nevada, and New Mexico as remaining Compact
members.62 The Rocky Mountain Compact defines low-level waste as specifically
excluding radioactive waste generated by defense activities, high-level waste (from
spent nuclear fuel reprocessing), transuranic waste (produced from nuclear weapons
fabrication), 11e(2) byproduct material,63 and mining process-related wastes.64
However, under Article VII(d) of the Compact, both the Compact’s board and the
host state may authorize management of any radioactive waste other than low-level
wastes upon consideration of various factors, such as the existence of transuranic
el em ent s . 65
A review of the legislative history of the Rocky Mountain Compact did not
appear to reveal the intent of Congress with respect to the specific responsibility of
the states concerning NRC-defined A, B, and C class wastes. A statement in the
legislative history of the Southeast Interstate Compact, however, may provide an
indication of Congress’s intent:
59 Requirements for Expanded Definition of Byproduct Material; Proposed Rule, 71 Fed.
Reg. 42951 — 42994 (July 28, 2006).
60 Id., at 42959-42960.
61 P.L. 99-240, § 226, 99th Cong., 1st Sess., 99 Stat. 1902 (1985).
63 Section 11(e)2 of the Atomic Energy Act, 42 U.S.C. § 2014(e)(2), defines byproduct
material to include the tailings or wastes produced by extraction or concentration of uranium
or thorium from any ore processed primarily for its source content.
64 P.L. 99-240, § 226, Art. II(g), 99th Cong., 1st Sess., 99 Stat. 1903 (1985).
65 P.L. 99-240, § 226, Art. VII(d), 99th Cong., 1st Sess., 99 Stat. 1908 (1985).
The definition of low-level waste in the compact may vary, but the compact
provides for adjustments and flexibility under its own procedures adequate to66
allow the compact to handle waste for which the states are responsible.
On the basis of the Compact’s Article VII and the language of H.Rept. 99-317,
quoted above, that accompanied H.R. 1267, it might be argued that the Compact’s
jurisdiction extends to TENORM when for disposal purposes TENORM meets the
criteria of Class A, B, or C low-level radioactive waste. Thus, the Compact’s
authority to dispose of low-level radioactive waste would appear restricted by the
Energy Policy Act of 2005. TENORM that poses a threat similar to the threat posed
by a discrete source of radium-226 would arguably be outside the jurisdiction of the
Compact. A diffuse source of radium-226 (i.e., TENORM ) that does not pose a
similar threat, however, would appear to remain within the jurisdiction of the
Compact’s Article VII(d) provision.
Uranium Mill Tailings
Uranium and thorium mill tailings are the waste byproducts of ore processed
primarily for its source material (i.e., uranium or thorium) content (10 C.F.R. 40.4).
The tailings contain radioactive uranium decay products and heavy metals. Mined
ores are defined as source material when containing 0.05 % or more by weight of
uranium or thorium (10 C.F.R. 20.1003). Byproduct material does not include
underground ore bodies depleted by solution extraction. Tailings or waste produced
by the extraction or concentration of uranium or thorium is defined under Section
11e.(2) of the Atomic Energy Act as amended by Title II of the Uranium Mill
Tailings Radiation Control Act of 1978 (UMTRCA , 42 U.S.C. 7901), and is simply
referred to as 11e.(2) byproduct material. UMTRCA provided for stabilization and
disposal of tailings to mitigate the hazard of radon diffusion into the environment,
and other hazards. Radon is a daughter-product of uranium/thorium radioactive
The NRC regulates the siting and design of tailings impoundments, disposal of
tailings or wastes, decommissioning of land and structures, groundwater protection
standards, testing of the radon emission rate from the impoundment cover,
monitoring programs, airborne effluent and offsite exposure limits, inspection of
retention systems, financial surety requirements for decommissioning and long-term
surveillance and control of the tailings impoundment, and eventual government
ownership of pre-1978 tailings sites under an NRC general license.67
66 H.R. REP. NO. 99-317, at 3 (1985).
67 U.S. NRC, Appendix A to Part 40 — Criteria Relating to the Operation of Uranium
Mills and the Disposition of Tailings or Wastes Produced by the Extraction or
Concentration of Source Material from Ores Processed Primarily for Their Source Material
Content, at [http://www.nrc.gov/reading-rm/doc-collections/cfr/part040/part040-appa.html].
Waste Disposal Policy Issues
The AEC first acknowledged the problem of waste disposal in 1955. Concerned
over the hazard of radioactive waste, the AEC awarded a contract to the National
Academy of Sciences to conduct research on methods to dispose of radioactive waste
in geologic media and recommend disposal options within the continental limits of
the United States.68 The Academy’s suggestion, at that time, was that disposal in
cavities mined out in salt beds or salt domes offered the most practical and
In the mid-1960s, the AEC conducted engineering tests on disposing spent fuel
in a salt mine near Lyons, Kansas. After developing conceptual repository designs
for the mine, AEC abandoned the Lyons project in 1972 due to technical difficulties.
The AEC went on to identify another site in a salt deposit and announced plans for
a retrievable surface storage program as an interim measure until a repository could69
be developed, but the plan was later abandoned.
In the 1970s, the Energy Research and Development Administration (ERDA),
and later the Department of Energy (DOE), began a program of screening various
geologic media for a repository (including salt deposits), and the federal sites of the
Hanford Reservation and Nevada Test Site. The national problem created by
accumulating spent nuclear fuel and radioactive waste prompted Congress to pass the
Nuclear Waste Policy Act of 1982 (NWPA). The potential risks to public health and
safety required environmentally acceptable waste disposal solutions, and the Act
provided for developing repositories to dispose of high-level radioactive waste and
spent nuclear fuel. Under the Act, the Department of Energy will assume title to any
high-level radioactive waste or spent nuclear fuel accepted for a disposal in a
repository constructed under the Act (42 U.S.C. 10131).
In 2002, the President recommended approval of the Yucca Mountain repository
site in Nevada. In a recent district court ruling, however, EPA’s 10,000-year safety
standard on radiation containment at the site was found to be inconsistent with the
congressionally mandated recommendations of the National Academy of Sciences.70
Depending upon successful resolution of the matter and the NRC’s granting a license,
the repository could begin to accept high-level waste and spent nuclear fuel in the
next decade. The Energy Department intends to submit a license application for
Yucca Mountain in mid-2008.
The controversy over DOE waste incidental to reprocessing appears to have
been resolved by redefining high-level radioactive wastes as excluding the residue
in high-level waste storage-tanks. However, Congress has requested the National
68 Committee on Waste Disposal, National Research Council, The Disposal of Radioactive
Waste on Land, National Academies Press, Washington D.C., 1957.
69 Commission on Geosciences, Environment and Resources, Nuclear Wastes: Technologies
for Separations and Transmutation, National Academies Press, Washington D.C., 1996.
70 Nuclear Energy Institute, Inc. V. Environmental Protection Agency, No. 1258 United
States Court of Appeals, July 9, 2004.
Research Council to study DOE’s plans to manage the residual tank waste and report
on the adequacy of the plans (P.L. 108-375). The DOE also operates the Waste
Isolation Pilot Plant in New Mexico to dispose of the transuranic waste generated by
the weapons program. New Mexico’s Governor, concerned that waste incidental to
reprocessing could end up at WIPP, ordered the state’s Department of Environmental
Management to amend WIPP’s hazardous waste permit so that only waste listed on
DOE’s Transuranic Waste Baseline Report is explicitly permitted for disposal at
When Congress passed the Low-Level Radioactive Waste Policy Act in 1980,
three states — Nevada, South Carolina, and Washington — hosted disposal sites for
commercially generated low-level waste. The Act encouraged the formation of
multi-state compacts in which one state would host a disposal facility for the member
states. The new facilities were to begin operation in by the end of 1985. When it
became clear that the deadline would not be met, Congress extended the deadline to
the end of 1992 in the amended Act of 1986 (P.L. 99-240). Since then, a new
commercial site has been licensed in Utah, and the Nevada site has closed.
Much of the low-level waste disposed of as Class A consists of debris, rubble,
and contaminated soil from decommissioning DOE and commercial nuclear facilities
that contain relatively little radioactivity. These decommissioning wastes make up
much larger volumes than low-level waste generated by operating nuclear facilities.
The term “low-activity” has been used in describing the waste, although it lacks
regulatory or statutory meaning. The National Research Council, in its interim report
Improving the Regulation and Management of Low-Level Radioactive Wastes found
that the current system of regulating low-activity waste lacked overall consistency.72
As a consequence, waste streams having similar physical, chemical, and radiological
characteristics may be regulated by different authorities and managed in disparate
In an Advance Notice of Proposed Rulemaking (ANPR), the EPA proposed
analyzing the feasibility of disposing of certain low-activity radioactive wastes in the
RCRA Subtitle C (hazardous waste) landfills, provided that legal and regulatory
issues can be resolved.73 The NRC, in collaboration with the state of Michigan,
recently permitted certain very low-activity wastes from decommissioning of the Big
Rock Point nuclear power plant to be sent to a RCRA Subtitle D (solid waste)
landfill, and other states have also determined that solid waste landfills offer
sufficient protection for low-activity waste.74 In a recent decision, however, the NRC
rejected a staff proposal to permanently allow disposal of low-activity waste in solid
71 New Mexico Environmental Department, NMED WIPP Information Page, at [http://www.
72 National Research Council of the National Academies, Improving the Regulation and
Management of Low-Level Radioactive Wastes — Interim Report on Current Regulations,
Inventories, and Practices, National Academies Press, 2003.
73 68 Federal Register 65,120, November 18, 2003.
74 Margaret V. Federline , U.S. NRC, Management and Disposal Strategies for Low-
Activity Waste in the U.S., White Paper, December 8, 2004.
waste landfills.75 If found to be acceptable, disposing of low-activity waste at RCRA
C and D landfills could alleviate the future capacity constraints at the three operating
low-level waste facilities.
Radioactive waste classification continues to raises issues for policymakers.
Radioactive waste generation, storage, transportation, and disposal leave little of the
national geography unaffected. The weapons facilities that processed and stored
radioactive waste have left a lasting and expensive environmental legacy that the
DOE is attempting to remedy by accelerating the cleanup of those contaminated sites.
The standards for public exposure to low-level radiation from the repository or
cleanup of the weapons facilities have not been reconciled by EPA and NRC. The
lower limit on what may be classified as radioactive waste is undefined, and both
EPA and NRC jurisdiction overlap on disposal of this waste stream.
75 “NRC Surprises, Rejects Rule on Nuke Material Recycling and Disposal,” The Energy
Daily, June 6, 2005
BWR — boiling water reactor.
curie — the basic unit describing the radioactive intensity of a material. One curie9
equals 37 billion (37 x 10) disintegrations/second, which is approximately the
activity of 1 gram of radium.
isotope — one of several nuclides of the same element, thus the same number of
protons in the nucleus (e.g. 92 for uranium) but differing in the number of neutrons,
hence U-234, U-235, U-238.
microcurie — one millionth of a curie (1 x 10-6 curie); also expressed as :curie
millicurie — one thousandth of a curie (1 x 10-3 curie); also expressed as mcurie
millirem — one-thousandth of a REM (Radiation Equivalent Man). It is the term for
the conventional unit of ionizing radiation dose (rad) equivalent used for radiation
MTHM — metric ton of heavy metal. 1000 kilograms (the U.S. equivalent of 2,200
lbs) of original uranium in fuel, excluding cladding and assembly hardware.
nanocurie — one billionth of a curie (1 x 10-9 curie); also expressed as 0curie.
picocurie — one trillionth curie (1 x 10-12 curie); also expressed as pcurie.
PWR — pressurized water reactor.
Transuranic elements — neptunium, plutonium, americium, and curium.
Table A-1. Uranium Mill Tailing Site Volume and Activity
Disposal Cell CellTailings
MillionMillion TotalAverage Average
CubicCubic Curies(226Curies/ Curies/gram226
Maybell Mill Site, CO 3.504.584450.000090.000000000
Mexican Hat Mill Site, UT3.484.551,8000.000090.000000000
Edgemont Mill Site, SD 3.003.925270.00013NA
Falls City Mill Site, TX 5.807.591,2770.000160.000000000
Ambrosia Lake Mill Site,5.206.801,8500.000270.000000000
Durango Mill Site, CO 2.53 3.311,4000.000450.000000000
Rifle Mills (Old & New)3.764.922,7380.000550.000000000
Salt Lake City Mill Site, UT 2.803.661,5500.000740.000000000
Source: U.S. DOE Energy Information Administration; “Remediation of UMTRCA Title I Uranium
Mill Sites Under the UMTRA Project Summary Table: Uranium Ore Processed, Disposal Cell
Material, and Cost for Remediation as of December 31, 1999,” at [http://www.eia.doe.gov/cneaf/
nuc lear /p age/umtr a/title1 sum.html] .
Notes: Total Curies and Average Curies expressed as Radium-226 equivalence; 1 cubic meter = 1.308
Table A-2. Low-Level Waste Commercial Disposal Site
Volume and Activity
SiteCubic FeetCubic MeterActivity CuriesCuries/cubic-meter
Richland, 295,300 8,363 92,980 11.12
Source: U.S. DOE, Table 1. Commercial Gross Volume and Activity
Distribution in Disposal of Low-Level and Mixed Low-Level Radioactive
Waste During 1990 (DOE/EH-0332p), August 1993.
Table A-3. Spent Fuel Specific Activity
Fuel Rod Type
BWR 1PWR 2PWR 3PWR 4PWR 5PWR 6
Fuel Rod array8x817x1717x1717x1717x1717x17
GW/d/MTH M 40 50 20 20 50 50
Decay time (years)14151010010100
Activity / assembly229594682731500002000045000040000
Nom vol/ assembly70.0818.104.22.168.190.19
So urce :1
Boiling Water Reactor, Appendix A, Table A-13, Yucca Mt. EIS2
Pressurized Water Reactor, Appendix A, Table A-12, Yucca Mt. EIS 3
Pressurized Water Reactor, Appendix C, P 82, Oak Ridge National Laboratory “Investigation of
Nuclide Importance to Functional Requirements Related to Transport and Long-Term Storage of LWR
Spent Fuel (ORNL/TM/12742), 1995.4
Appendix C, P 82, ORNL/TM/12742.5
Appendix C, P 85, ORNL/TM12742.6
Appendix C, P 85, ORNL/TM12742.7
Table A-18, Reference Characteristics for Average Commercial Spent Fuel Assemblies, Appendix
A, Inventory of Characteristics of Spent Nuclear fuel, High-Level Radioactive Waste, and Other
Materials, Yucca Mountain EIS.
Notes: A typical fuel rod used in commercial nuclear power reactors consists of uranium dioxide
pellets surrounded by zirconium alloy cladding. The uranium oxide pellets consist of 3-4% fissionable
uranium-235, and a balance of nonfissionable U-238. An individual fuel assembly consists of arrays
of fuel rods. The Energy Information Administration (EIA) notes 131 reactor fuel assembly types on
its Nuclear Fuel Data Survey Form RW-859 (OMB No. 1901-0287). The assemblies range in weight
from ~70 kilograms uranium for a Humboldt Bay Assembly Class (boiling water reactor) to ~ 464
kilograms uranium for a Babcock & Wilcox 15 x 15 Assembly Class (pressurized water reactor).
During the sustained chain reaction in an operating reactor, the U-235 splits into highly radioactive
fission products, while the U-238 is partially converted to plutonium-239 by neutron capture, some
of which also fissions. Further neutron capture creates other transuranic elements.
Figure A-1. 10 CFR 61.55 Table 1
Figure A-2. 10 CFR 61.55 Table 2