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OCR for page 55
~2
Anticipated Inventories of Radioactive
or Radioactively Contaminated Materials
This chapter summarizes current estimates of the quantities of slightly radio-
active solid material (SRSM) expected to arise over the next 25 years from
cleanup and decommissioning of licensed nuclear facilities and from other facili-
ties that may contain SRSM. These estimated inventories include materials from
U.S. Nuclear Regulatory Commission (USNRC)-licensed facilities, from facili-
ties licensed by agreement states, and from U.S. Department of Energy (DOE)
and Department of Defense (DoD) facilities that do not require a USNRC license.
Radioactively contaminated materials known as naturally occurring radioactive
material (NORM), naturally occurring and accelerator-produced radioactive ma-
terial (NARM), or technologically enhanced NORM (TENORM) also arise from
a variety of activities that are not subject to the Atomic Energy Act (AEA) and
thus are not regulated by the USNRC. The latter materials are not federally
regulated but are regulated by state agencies in some states or not regulated at all
in other states. Thus, the USNRC needs to be aware that any new regulations
regarding clearance of SRSM could also have impacts on the management of
contaminated materials that are currently unregulated at the federal level. Some
perspective is also provided in this chapter on the relative fraction of the annual
amount of recycled commercial steel scrap that cleared SRSM could comprise if
clearance for unrestricted recycle were to be approved.
The committee did not find readily available information on inventory and
anticipated dates for disposition of radioactive materials. The information cur-
rently available covers some industries but not others. In some cases, inventories
of radioactive materials have been developed based on what is currently being
55
OCR for page 56
56
THE DISPOSITION DILEMMA
generated from active licensed operations. Other inventories have been devel-
oped based on projections of future decommissionings.
Inventories for materials that fall outside the legal requirements for radioac-
tive waste management are not as carefully developed. The unlicensed industry
segments, such as many that produce NORM or TENORM, deal with radioactive
material as an unwanted byproduct associated with industrial processes. Inven-
tory information about NORM and TENORM tends to focus on the concentra-
tions of radium, uranium, or thorium and daughter radionuclides that they con-
tain, rather than on total inventories.
Therefore, one must often infer or estimate the amount of materials that may
satisfy particular clearance criteria based on information created for a different
purpose. This chapter relies heavily on a recent report Inventory of Materials with
Very Low Levels of Radioactivity Potentially Clearable from Various Types of
Facilities, which was prepared for the USNRC by Sanford Cohen & Associates,
Inc. (SCA, 2001~. Information from this source has been supplemented with
information from various published and Internet sources and from materials pre-
sented to the study committee.
The characteristics and quantities of radioactive materials used or possessed
by USNRC licensees are discussed in the following section. To provide the bases
for the cost analysis given in Chapter 4, the emphasis in that section is on radio-
active material streams arising from the decommissioning of licensed power
reactors. To complete the picture of radioactive materials in the United States,
summary information on the other licensed and unlicensed radioactive material
streams is presented in the second section.
INVENTORIES OF CONTAMINATED MATERIALS ARISING FROM
DECOMMISSIONING OF USNRC-LICENSED FACILITIES
The majority of USNRC-licensed facilities can be divided into four types,
each of which produces a characteristic body of radioactive materials during
operations and decommissioning: (1) nuclear reactors (electric power, materials
testing, and research reactors); (2) fuel cycle facilities (uranium milling, UFO
[uranium hexafluoride] conversion plants, and uranium fuel fabrication); (3) non-
fuel-cycle facilities (radioactive material processing, research laboratories, medi-
cal treatment, radiography, etc.~; and (4) independent spent fuel storage installa-
tions (ISFSIs), which store spent fuel from power reactor operations.
Because of the substantial number (more than 100) and large size of electric
power reactors, they are the source of about 75 percent of the radioactive materi-
als in the United States that require disposal in licensed low-level radioactive
waste (LLRW) disposal sites. Power reactors also provide SRSM that is cleared
from regulatory control. SRSM arising from the latter three types of facilities is
examined in less detail in this report because the quantities of radioactive materi-
OCR for page 57
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
57
als arising during operation or during decommissioning are small compared to
the quantities arising from power reactor decommissioning.
Power Reactors
Some data are available for estimating the types and annual quantities of
radioactive materials arising from the operation of power reactor facilities that
currently dispose of their LLRW at licensed LLRW disposal facilities. Additional
data and various estimates are available to define the types and total quantities of
radioactive materials resulting from decommissioning power reactor facilities.
The decommissioning data and estimates presented in Table 3-1 are derived from
two USNRC reports: NUREG/CR-5884 (Konzek et al., 1995) for a reference
pressurized water reactor (POOR) and NUREG/CR-6174 (Smith et al., 1996) for a
boiling water reactor (BWR). Also presented in the table are estimates of the
sums of the quantities of these materials expected to arise from the total U.S.
population of power reactors. These population estimates were scaled from the
reference reactor quantities using multiplication factors derived from the SCA
(2001) report on inventory using the following equations:
Mpop.p = MRef.p Ii (Ppi/PRef.p)
and
Mpop B = MRef B Pi (PB1/PRef.B)
where Mpop p and Mpop B are the PWR and BWR population multipliers, respec-
tively, MRefp and MRefB are the weights of radioactive materials postulated to
arise from decommissioning the reference PWR and BOOR, respectively; PRefp
and PRefB are the rated power levels of the reference PWR and BOOR, respec-
tively, and Ppi and PBi are the rated power levels of the individual PWRs and
BWRs that make up the U.S. population of power reactors. In essence, the popu-
lation multiplier for a PWR or BWR represents the number of reference PWRs or
BWRs that would contain the same total amount of structural material as is
contained within the total populations of PWRs and BWRs that exist currently in
the United States. Because many of the reactors are smaller than the reference
reactors, the population multipliers are smaller than the actual number of each
type of reactor in the total population.
For this analysis, the total volume of potential LLRW estimated to arise from
decommissioning a power reactor is divided into three categories: (1) activated
materials,] including the reactor pressure vessel and internals and the activated
portions of the biological shield; (2) nonreusable contaminated materials such as
Materials made radioactive through irradiation of stable nuclides by neutrons, protons, electrons,
or other particles or radiation.
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58
TABLE 3-1 Volume of Materials Arising from Power Reactor
Decommissioning (cubic meters)
THE DISPOSITION DILEMMA
Material Type
PWR Volumesa BWRVolumeb Population Totals
Activated (LLRW) 547 889 60,900
Nonclearable (LLRW) 1,800 1,520 159,000
Metallic SRSM 5,830 12,700 743,000
Excluded (30%) as LLRW 1,750 3,820 233,000
Net SRSM 4,080 8,900 521,000
Concrete SRSM 69,500 99,700 7,360,000
Total volumes SRSM 73,600 109,000 7,880,000
Population multipliersC 63.76 29.23
NOTE: All values are rounded to three significant figures.
aKonzek et al. (1995).
bSmith et al. (1996).
CData derived from SCA (2001). Each multiplier represents the number of reference reactors of
that type that would contain the same total amount of structural material as is contained within the
total population of each reactor type.
ion-exchange resins, filters, plastics, contaminated equipment insulation, and re-
moved contaminated concrete surfaces; and (3) metallic SRSM that might be
uncontaminated but is from a radioactive work area or that might be only slightly
contaminated. The metallic SRSM includes pool liners, piping, tanks, valves,
pumps, heat exchangers, and similar items. Because of the complexity of their
inner and outer surfaces, it is difficult to demonstrate that some of these items
(such as heat exchangers, pumps, and valves) have been decontaminated suffi-
ciently to permit release under a clearance standard. An examination of the tables
of system components presented in Konzek et al. (1995) shows that roughly 30
percent of the volume of the metallic SRSM in those tables would probably be
excluded on the basis of structural complexity. For this analysis, that 30 percent
fraction has been excluded from the volume of SRSM and equipment when
calculating the volumes in Table 3-1. The same fraction was assumed to be
applicable to the metallic SRSM arising from decommissioning a BOOR.
The structural concrete rubble arising from demolition of decontaminated
facility structures (clearable concrete) represents the largest single component of
the decommissioning wastes. The volumes presented in the table are, for the
purposes of analysis, based on the assumption that after contaminated surfaces
and activated concrete have been removed, the remaining concrete structures are
essentially uncontaminated and may be suitable for clearance or conditional clear-
ance (e.g., for reuse in highway construction or other uses, or for disposal in
municipal waste Resource Conservation and Recovery Act [RCRAI Subtitle D
landfills). The volumes of concrete SRSM rubble are larger than the combined
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ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
TABLE 3-2 Weights of Slightly Radioactive Solid Material from Power
Reactors (metric tons)
59
Material Type
PWR Weights
BWR Weights
Population Totals
Metallic SRSM 7,860 18,700 1,050,000
Excluded as LLRW (30%) 2,360 5,610 315,000
Net metallic SRSM 5,500 13,100 735,000
SRSM concretea 83,600 120,000 8,850,000
Total weight SRSM 89,100 133,000 9,590,000
NOTE: Values are rounded to three significant figures and were derived from Konzek et al.
(1995) and Smith et al. (1996).
aFrom Table 3-1, by assuming that the density of concrete rubble is 1.2 metric tons per cubic
meter.
volumes of all of the other SRSM by at least a factor of 10. Although it is
assumed that beyond the surface, the remainder of the concrete is uncontami-
nated, determining what to do with the concrete is complicated by several factors.
It can be difficult, in practice, to determine the quantities and levels of radionu-
clide contamination that have penetrated into the concrete. There are also sam-
pling and analysis costs associated with demonstrating that material is clean, as
discussed in Chapter 6 in Measurement Cost. Public perception and regulatory
factors can affect choices a licensee makes on disposition of such material, such
as whether concrete is left as on-site fill after the license of a site is terminated.
The committee was informed that these difficulties with on-site disposal have
been encountered with at least one decommissioning of a reactor site, Maine-
Yankee.
Table 3-2 presents the weights of SRSM and clearable concrete estimated
from the reference PWR and BOOR. Population totals assume that the same popu-
lation-scalin~ factors anclied to material volumes in Table 3-1 also anclv to
material weights.
The time distribution of these decommissioning wastes is a significant con-
sideration. The quantities of material arising from decommissioning nuclear
power reactors will be distributed over an extended period because of the varying
dates at which their licenses are scheduled to expire (SCA, 2001, Tables 2-26, 2-
27~. Figure 3-1 illustrates this time distribution for the weight of metallic and
concrete SRSM, given the shutdown dates stated in SCA (2001~. If licenses are
extended for an additional 20 years, which seems probable for most facilities, the
large quantities of material shown in the figure would be generated up to 20 years
later, with little material resulting from decommissioning until after 2030.
With or without license extensions, the weights of decommissioning mate-
rial requiring disposition (about 8 percent metals and 92 percent concrete) range
from about 100,000 to more than 1 million metric tons per year during a 25-year
OCR for page 60
60
THE DISPOSITION DILEMMA
1, 200, 000 -
1, 000, 000 -
800, 000 -
600, 000 -
400, 000 -
200, 000 -
I ~ Concrete
111~ Metals
~ . ~
> ~~ ~~ ~~ ~3~ ~3> ~3~ ~~ ~~ ~~ ~~>
Year
FIGURE 3-1 Time distribution for generation of slightly radioactive solid material from
U.S. power reactor decommissionings. SOURCE: Adapted from SCA (2001~.
period. The average is around 360,000 metric tons per year, or the equivalent of
decommissioning four or five power reactor units per year. If most of the cur-
rently operating reactors do receive 20-year license extensions and if the reactors
already in safe storage are decommissioned as assumed in SCA (2001), most of
the weights shown in Figure 3-1 between 2006 and 2030 would move roughly 20
years into the future, to 2026 to 2050. Relatively small quantities of SRSM from
power reactor decommissioning would be generated during the next three de-
cades.
It is instructive to compare the amount of ferrous metals arising from decom-
missioning activities at commercial power reactors with the total amount of fer-
rous metal scrap currently being recycled commercially. The committee heard
from a representative of a major scrap broker-processor2 that the average amount
of obsolete scrap recycled into commercial steelmaking in the years 1997-1999
was about 42 million metric tons per year. During the same period, U.S. produc-
tion was about 98 million metric tons per year. The amount of nonactivated, steel
SRSM arising from decommissioning the population of U.S. power reactors, as
shown in Table 3-2, ranges from 0.74 million to 1.05 million metric tons (de-
pending on the amount excluded as LLRW). Based on the distribution of current
license expiration dates for U.S. power reactors over a 25-year period, the aver-
age amount of steel SRSM would be between 30,000 and 42,000 metric tons per
2Presentation to the committee by Ray Turner, David I. Joseph Company, June 13, 2001, Wash-
ington, D.C.
OCR for page 61
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
61
year. If the larger quantity (42,000 metric tons per year) was recycled, the poten-
tially radioactive scrap would constitute only about 0.1 percent of the total steel
scrap recycled each year. This small amount of metallic SRSM indicates that the
effect on the available scrap metal resources is negligible if the metal is not
recycled.
Nonpower Reactors
There are 46 USNRC-licensed research reactors in the United States, of
which 36 are still operational (SCA, 2001, Table 2-79~. Konzek et al. (1995)
developed a decommissioning materials inventory for a reference research reac-
tor that is presented again in SCA (2001~. Also given in SCA (2001) are decom-
missioning data from four retired research reactors. The data from these four
reactors were used in a least-squares analysis to develop a scaling factor for the
weight of decommissioning material as a function of the licensed power rating of
each research reactor relative to the reference research reactor (SCA, 2001, p. 2-
138~. The resulting equation for the scaling factor is Mi/MR = [Pi/PRji 08~3, where
M is the weight of material and P is the power rating, for the ith reactor and the
reference reactor, respectively. The R2 value for the fit of the data to the equation
was 0.97.
The power ratings for the four research reactors used in the analysis ranged
from 5 W to 20 MW, and the power rating of the reference research reactor was
just 1.1 MW. Because a certain amount of facility structure is needed almost
regardless of the power rating of the contained reactor, this scaling factor may
underestimate the quantities of materials arising from research reactors having
the much lower power ratings. Computing this factor for each of the 46 licensed
research reactors and summing over that population yields the population scaling
factor (65.79~. Multiplying the weights of each category of materials (structural
steel, concrete, system steel) from the reference research reactor by the popula-
tion scaling factor yields the population weights for each material category from
U.S. research reactors, as shown in Table 3-3. The weights of structural steel and
concrete SRSM are assumed to all be clearable, without any exclusions for LLRW
materials. The study committee also assumed that metallic SRSM from the sys-
tem steel category would have the same 30 percent fraction that would have to be
disposed of as LLRW as assumed in the previous section on power reactors. The
inventory of steel and concrete from research reactors represents about 1.4 per-
cent of the total weight of SRSM from the power reactors.
INVENTORIES OF RADIOACTIVE WASTE FROM
OTHER LICENSED AND UNLICENSED SOURCES
Radioactive materials are generated in a number of industrial environments,
where the sources range from dilute to concentrated and from small volumes to
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62
THE DISPOSITION DILEMMA
TABLE 3-3 Decommissioning Materials Inventory from the Population of
U.S. Research Reactors (metric tons)
Composite Reactor Structural Steel Concrete System Steel
Activated 6.5
Nonclearable 11 2.0
SRSM 113 1,910 46.0
Excluded (30%) 13.8
Net SRSM 113 2,010 39.9
Population weight SRSM 7,400 125,000 2,100
NOTE: Values are rounded to three significant figures. Population scaling factor is 65.79.
SOURCE: Data derived from SCA (2001).
large volumes. The information presented here is intended to provide a broad
view of the types and quantities of radioactive materials present in the United
States. Some of these materials are under federal regulatory control, others are
under the control of state agencies, and still others may not be under any regula-
tory control. The inventories include radioactive materials generated by (1) fuel
cycle and (2) non-fuel cycle facilities, both categories of which are licensed,
permitted, and regulated by the USNRC and agreement states; (3) facilities sub-
ject to the USNRC' s Site Decommissioning Management Plan (SDMP); (4) DOE
facilities; (5) DoD facilities; (6) facilities regulated by the Environmental Protec-
tion Agency (EPA Superfund sites) or state agencies; and (7) industries that
produce NORM, NARM, or TENORM.
Steel and concrete SRSM arise from decommissioning activities at fuel-
cycle and non-fuel-cycle facilities. The SRSM generated at these sites will in-
clude some or all of the following:
.
Surface-contaminated equipment and material (i.e., concrete), and
· Materials that are not from controlled radioactive areas and may be desig-
nated as clearable, depending upon the type of facility.
In general, activated metals and concrete have been and will continue to be
disposed at licensed LLRW disposal facilities. These activated materials are not
considered candidates for clearance, except where the concentration of activation
products is very minimal. The category of surface-contaminated equipment and
material includes some materials that are unlikely to be clearable and some that
might be clearable after application of an appropriate decontamination technol-
ogy. The types and quantities of radioactive materials arising from decommis-
sioning each type of facility are discussed briefly below.
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ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
USNRC-Licensed Fuel Cycle Facilities
63
There are basically four types of fuel cycle facilities licensed by the USNRC:
uranium mills, uranium hexafluoride conversion plants, uranium oxide fuel fabri-
cation plants, and ISFSIs.
Uranium Mills
The population of uranium mills consists of four conventional surface ore
crushing and/or leaching facilities and up to seven (one is not yet operational) in
situ leaching facilities. In the surface mills, the waste materials from decommis-
sioning are generally disposed by adding them to the ore tailings piles. Little
waste remains that would require disposal at an LLRW facility. The in situ
leaching facilities produce some wastes for LLRW disposal, and some of their
surface structures and equipment may be conditionally clearable. The contami-
nants present are primarily natural uranium (235U and 238U and their daughter
products). No data are readily available on the volumes and weights of material
and equipment that will arise from decommissioning in situ leaching facilities.
However, because of the simplicity of these facilities, the committee expects that
the quantities will be small.
Uranium Hexafluoride Conversion Plants
Decommissioning of the two existing uranium hexafluoride conversion plants
is expected to be completed ultimately. One is currently operating; the other has
been undergoing decommissioning for the past eight years. Although these two
plants use different chemical processes, the SCA (2001) report assumes that they
are sufficiently similar that a scaling factor of 2 is appropriate for calculating the
size of the population waste inventory. The anticipated contaminants are prima-
rily natural uranium (235U and 238U and their daughter products), with concentra-
tions in the range of 10 tolO,000 pCi/g. Table 3-4 gives the estimated weights of
radioactive materials arising from decommissioning these facilities. For the un-
cleared equipment, the study committee accepted the assumption made by Elder
(1981) that 40 percent is LLRW and 60 percent is SRSM. For the non-LLRW
concrete and structural steel (including reinforcing bar in concrete, or rebar),
Elder (1981) assumed that 40 percent is SRSM and 60 percent is clearable.
Because there are only two of these facilities, the quantities requiring disposition
are small.
Uranium Fuel Fabrication Facilities
There are seven uranium fuel fabrication plants presently licensed in the
United States. Their licenses are currently scheduled to expire 2001 to 2009. At
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64
THE DISPOSITION DILEMMA
TABLE 3-4 Decommissioning Materials Inventory from the Population of
U.S. Uranium Hexafluoride Conversion Plants (metric ton)
Materials Structural Steel Concrete Equipment
LLRW 161 928
SRSM 616 3,250 1,390
Clearable 922 4,870 271
Total clearable 1,540 8,120 1,660
NOTE: Values are rounded to three significant figures.
SOURCE: Data are derived from SCA (2001).
least four of these plants will probably have their licenses extended, in order to
serve the U.S. nuclear power industry and the nuclear navy. Thus, the material
inventories arising from decommissioning the population of uranium fuel fabri-
cation plants, shown in Table 3-5, are likely to be distributed over the next 30
years or more.
The principal contaminants are low-enriched uranium (235U and 238U and
their daughter products). The radioactivity levels on plant equipment could range
from essentially zero up to 38,000 pCi/g.
For the committee's analysis, only six of the seven plants were considered;
the naval reactors fuel plant was omitted. Table 3-5 uses a committee-derived
population scaling factor, developed using the formula in SCA (2001), for esti-
mating the weights of materials in other plants from the weights in a reference
fuel fabrication plant (Wilmington, North Carolina), for which data were given in
SCA (2001~. For equipment, the same assumptions were used that were made for
TABLE 3-5 Decommissioning Materials Inventory from the Population of
U.S. Fuel Fabrication Plants (metric tons)
Materials Structural Steel Concrete Equipment
LLRW 347 2,010
SRSM 6,500 21,000 3,020
Clearable 9,750 31,500 4,400
Total clearable 16,300 52,500 7,420
NOTE: The committee used a scaling factor of 3.88 applied to the reference plant value. Values
are rounded to three significant figures.
SOURCE: Reference plant data are from SCA (2001).
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ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
65
the uranium hexafluoride plants. Namely, of the uncleared material, 40 percent
would be disposed as LLRW and 60 percent is SRSM. For concrete and structural
steel (including rebar), 40 percent is assumed to be SRSM and 60 percent is
assumed clearable.
Independent Spent Fuel Storage Installations
An independent spent fuel storage installation (ISFSI) is a facility in which
spent nuclear fuel from a nuclear power reactor is stored, primarily fuel that is in
excess of the capacity of the spent fuel pool at the reactor. There are 15 ISFSI
facilities in service in the United States employing five design concepts:
1. Vertical ventilated concrete casks (four sites),
2. Horizontal storage modules (eight sites),
3. Vertical metal casks (one site),
4. Modular vault dry storage (one site), and
5. Water-filled pool (one site).
Additional facilities are planned to be constructed in the coming decade to ac-
commodate the excess spent fuel accumulating at reactors until a federal deep
geologic repository begins receiving spent fuel for disposal.
The interior surfaces of the metal storage canisters in the dry storage con-
cepts will undoubtedly be contaminated and might actually be activated to very
low activity levels. However, the quantities of SRSM are not large and would
accumulate slowly. The accumulation rate will be determined by the rate at which
the geologic repository receives spent fuel. Thus, the committee has concluded
that these materials will not contribute significantly to the total quantity of mate-
rials entering the disposal stream during any given year.
Non-Fuel-Cycle Licensees of the USNRC or Agreement States
There were roughly 21,000 radioactive materials licensees in the United
States in 2000, consisting of roughly 5,000 USNRC licensees and nearly 16,000
agreement state licensees. Of the various types of licensees in this group, those
involved in research and development, medical applications, nuclear pharmaceu-
ticals, and the manufacture of sealed sources and radio-labeled compounds gen-
erate materials potentially subject to a clearance regulation. The estimates for
radioactively contaminated materials generated by these licensees were calcu-
lated by multiplying the estimated weight of SRSM in a reference facility by the
number of USNRC-licensed facilities of the same type. This result was then
multiplied by 4 to account for the 75 percent of radioactive materials licenses
issued by agreement states (SCA, 2001~.
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66
Hospitals
THE DISPOSITION DILEMMA
SRSM in hospitals consists of floors, walls, equipment (metal), and cabinets
(wood). The total U.S. inventory is approximately 436,000 metric tons, of which
an estimated 8,720 to 21,800 metric tons is disposed annually. Most of these
materials are clearable. However, some small percentage contains fixed 3H and
14C contamination that must be disposed of as biomedical LLRW.
Research and Development Laboratories
The inventory of possibly radioactive materials in the reference research and
development laboratory was estimated in SCA (2001) to be about 1 metric ton of
equipment and about 2.5 metric tons of concrete. Hot cells and fume hoods were
not included in the estimates, since they are expected to contain too much con-
tamination to be considered for clearance. The total U.S. inventory for research
and development laboratories was estimated by SCA (2001) to be about 2,058
and 5,145 metric tons of equipment and concrete, respectively.
Manufacturers of Sealed Sources and Radio-Labeled Compounds
Manufacturers of sealed sources and radio-labeled compounds use licensed
radioactive materials in hot cell laboratories. Potentially clearable materials con-
sist of approximately 1.7 metric tons of metal, concrete, and asphalt tiles in the
reference facility, or about 107 metric tons for the 63 such facilities in the United
States (SCA, 2001).
Biomedical Wastes
Biomedical radioactive waste is generated under either USNRC or agree-
ment state licenses by institutions engaging in medical, biological, or academic
research and in universities and hospitals where radioactive materials are used for
research, diagnosis, or treatment of disease. Biomedical use of radioactive mate-
rials typically generates small volumes of LLRW with low content of radioactiv-
ity. Although short-lived radionuclides are most often used in biomedical re-
search, longer-lived radionuclides such as tritium and 14C are also used.3 The
longer-lived wastes are disposed at licensed LLRW facilities after pretreatment
to reduce waste volume, which reduces disposal costs. Much of the short-lived
waste can be managed by storage for decay, with subsequent disposal according
to the nonradioactive constituents of the wastes (NRC, 2001~.
3criteria in lo CFR Part 20 allow disposal of volume-contaminated animal tissue containing less
than 1.85 ksqlg of 3H or 14c as if it were not radioactive.
OCR for page 67
ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
Facilities Under the Site Decommissioning Management Plan
67
The USNRC is regulating the decommissioning of 28 facilities under the
SDMP. Radioactive residues at these facilities consist primarily of ore or slag
containing elevated concentrations of natural radioactivity (i.e., uranium and
thorium and their daughter products). Approximately 4,100 cubic meters (9,840
metric tons) of concrete SRSM is expected to be produced. About 84,000 cubic
meters of slag from previous processes may be recovered for reprocessing or
other controlled uses.
DOE Facilities
Numerous DOE facilities have moved from production to decontamination
and decommissioning. Assuming that 25 percent of the steel and iron present at
these facilities cannot be recycled for economic or radiological reasons, recent
studies estimate that about 1 million metric tons of metallic SRSM exist in
current inventory or are expected to become available by 2035 (SCA, 2001~. An
estimated 60 percent of these metals will come from decommissioning the gas-
eous diffusion plants located at Oak Ridge, Tennessee (the K-25 plant); Piketon,
Ohio ("Portsmouth"~; and Paducah, Kentucky. The radionuclides of concern at
the gaseous diffusion plants include 235U,238U 239Pu 237Np and 99Tc Concen
"rations tend to be dilute, with 78 percent of the ferrous metals estimated to
contain less than 4,400 Bq/kg (120 pCi/g). (The significance of these concentra-
tions depends on the scenarios whereby the radionuclides could expose humans
to a radiation dose. This issue is covered in detail in Chapter 5.)
As discussed in the section on decommissioning power reactors, the amount
of steel scrap recycled into commercial steelmaking is currently about 42 million
metric tons per year. The projected 1 million metric tons of steel SRSM generated
from DOE decommissioning and cleanup operations are expected to become
available over about a 25-year period, or an average of about 40,000 metric tons
per year. Thus, if recycled, this amount of slightly contaminated scrap would
constitute only an additional 0.1 percent of the annual stream of recycled obsolete
steel.
Available data are insufficient to characterize the inventory of concrete
SRSM from the DOE complex. One DOE study (DOE, 1996) estimates that
about 3.1 million cubic meters (~3.7 million metric tons) of rubble and debris will
result from all decontamination and decommissioning operations through 2050.
(Together with the estimate of steel SRSM given above, this data implies a mass
ratio of concrete to metal of 3.7 to 1 an aggregate number that could vary
widely by individual site and type of facility.) Another DOE study (DOE, 1999)
has estimated the DOE concrete volume would be over 10 million cubic meters
(greater than 12 million metric tons). These two estimates illustrate the kind of
uncertainty that exists in the amount of potentially contaminated concrete present
in the vast DOE complex.
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68
THE DISPOSITION DILEMMA
Much of the concrete will probably be used as on-site fill material, after in
situ removal of isolated areas of contamination with an appropriate decontamina-
tion technology. As shown in Table 3-6, the quantity of radioactively contami-
nated soil that may arise during cleanup efforts at DOE facilities could be as large
as 76 million cubic meters.
DoD Facilities
Many DoD facilities are licensed by the USNRC, including hospitals, labo-
ratories, proving grounds, some nuclear reactors, weapons facilities, and missile
launch sites. The DoD holds approximately 600 licenses and/or radioactive mate-
rials permits, of which three-quarters are for sealed sources (and therefore gener-
ate no radioactive waste). Most of these licenses cover a spectrum of operations
similar to those found in the civilian world. As noted, the USNRC does not
license naval reactors and associated propulsion units. Overall, about 115,000
cubic feet of LLRW is generated annually from DoD facilities. Most of this waste
(greater than 90 percent) is from cleanup efforts rather than operations.
TABLE 3-6 Sites Containing Radioactively Contaminated Soils
Authority Location or Type No. of Sites Soil Volume (103 m3)
DOE Fernald 1 2,100
Hanford 1 23,600
Idaho 1 720
Miamisburg 1 110
Nevada Test Site 1 16,000
Oak Ridge Reservation 1 133
Paducah 1 990
Portsmouth 1 25
Rocky Flats 1 460
Savannah River 1 19,000
Weldon Springs 1 480
Lawrence Livermore 2 2,212
National Laboratory
Los Alamos National 1 9,900
Laboratory
Sandia National 2 221
Laboratories
USNRC or Nuclear fuel cycle (active 199 32
agreement states and inactive), including
nuclear power plants
Byproduct licensees 1,994 60
Other nonfederal Rare-earth mill sites 17 120
SOURCE: Wolbarst (1999).
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ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
EPA-Regulated Superfund Sites
69
For more than a half century, radioactive materials have been produced and
used in weapons production, power generation, and industrial and medical appli-
cations. Because these materials were frequently released into the environment,
thousands of sites within the United States have become contaminated some
slightly, some heavily. Furthermore, other industrial activities not focused on
using radioactive materials have resulted in the concentration of significant
amounts of NORM at various sites. As reported by the EPA (63 Federal Register
51982-51888; September 29, 1998), there are about 1,200 sites on the National
Priorities List (NPL) of facilities needing cleanup, of which about 150 are federal
facilities. According to one estimate, at least 75 sites on the NPL are radioac-
tively contaminated (Wolbarst, 1999~. A current estimate by EPA places the
number of sites on the NPL having radioactive contamination at approximately
60 (EPA, 2001~.
Although DoD and DOE are responsible for the majority of these sites, more
than 20 of them did not originate from federal agency activities. Table 3-6 illus-
trates the approximate inventory of sites containing soils contaminated with ra-
dioactivity, their locations, and the estimated volumes of contaminated soil asso-
ciated with each site.
NORM, NARM, and TENORM
Several types of industrial activity coincidentally enhance the concentration
of NORM in waste residues, resulting in the generation of TENORM. The typical
radionuclides of concern in TENORM are members of the thorium and uranium
decay series. The type of processing performed on natural materials and the time
expired since processing determine the equilibrium status of the radionuclides
present.
Industries associated with TENORM production may produce radioactively
contaminated scrap metals, in addition to TENORM-containing waste residues.
These industries include the following:
Petroleum production,
Uranium mining,
Phosphate and phosphate fertilizer production,
Fossil fuel combustion facilities (power plants),
Drinking water treatment facilities,
Metal mining and processing facilities, and
Geothermal energy production facilities.
Currently, there are no federal statutes explicitly regulating TENORM, al-
though some waste streams fall under the jurisdiction of various EPA regulations
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70
THE DISPOSITION DILEMMA
or programs. Several agreement states regulate TENORM under their general
rules governing possession of radioactive materials, and 11 states have promul-
gated regulations specifically addressing TENORM. Table 3-7 lists estimates of
TENORM wastes generated annually, with associated ranges of uranium, tho-
rium, and radium concentrations. Waste management practices or clearance of
TABLE 3-7 Sources, Quantities, and Concentrations of TENORM
Concentrationa (Bq/kg)
Metric Tons
Waste Source per Year Uranium Thorium Radium
Uranium overburden 3.8 x 104 1.8 x 103 990 920
Phosphate 5.0 x 104 Bkg-3.0 x 103 Bkg-1.8 x 103 400-3.7 x 106
Phosphogypsum 4.8 x 104 Bkg-500 Bkg-500 900-1.7 x 103
Slag 1.5 x 103 800-3.0 x 103 700-1.8 x 103 400-2.1 x 103
Scale 4.5 x 10° 1.1 x 10 3-
3.7 x 106
Phosphate fertilizers 4.8 x 103 740-2.2 x 103 37-180 180-740
Coal ash 6.1 x 104 100-600 30-300 100-1.2 x 103
Fly ash 4.4 x 104
Bottom ash 1.7 x 104
Petroleum production 2.6 x 102 bkg-3.7 x 106
Scale 2.5 x 1ol bkg-3.7 x 106
Sludge 2.3 x 102 bkg-3.7 x 103
Petroleum processing 210pb and 210
Refineries >4.0 x 103
Petrochemicals >4.0 x 103
Gas plants 210pb and 210
Water treatment 3.0 x 102 100-1.5 x 106
Sludge 2.6x 102 100-1.2x 103
Resins 4.0 x 1ol 300-1.5 x 106
Mineral processing 1.0 x 106 6-1.3 x 105 8-9.0 x 105 <200-1.3 x 105
Rare earths 2.1 x 1ol 2.6x 104- 9.0X 103 1.3 x 104-
1.3 x 105 9.0 x 105 1.3 x 105
Zr, Hf. Ti, Sn 4.7 x 102 6-3.2 x 103 8-6.6 x 105 300-1.8 x 104
Alumina 2.8 x 103 400-600 500-1.2 x 103 300-500
Cu and Fe 1.0 x 106 <400 <400 <200
Geothermal waste 5.4 x 1 ol 400- 1.6 x 104
Paper mills >3.7 x 103
Total 2.27 x 106
abkg = background radiation level.
SOURCE: USNRC (2001a).
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ANTICIPATED INVENTORIES OF RADIOACTIVE MATERIALS
71
materials from regulatory control depends on both the bulk quantity of the mate-
rial involved and the concentrations of these key radionuclides in it.
As shown in Table 3-7, the amount of TENORM that could fall under
USNRC waste disposal regulations would be about 2.3 million metric tons per
year, on a continuing basis.
FINDINGS
Finding 3.1. Licensees may seek to clear about 740,000 metric tons of metallic
SRSM that arise from decommissioning the current population of U.S. power
reactors during the period 2006 to 2030 (about 30,000 to 42,000 metric tons per
year). About 8,500 metric tons per year are expected to arise from decommission-
ing USNRC-licensed facilities other than power reactors during the same time
period. The total quantity of metal from both power reactor and non-power reac-
tor licensees, up to approximately 50,000 metric tons per year, represents about
0.1 percent of the total obsolete steel scrap that might be recycled during that
same 25-year period.
Finding 3.2. If most of the licensees of currently operating reactors obtain 20-
year license extensions, relatively little SRSM will arise from power plant de-
commissioning during the 2006-2030 period.
Finding 3.3. Because of the difficulty of determining the quantities and levels of
contamination that have penetrated into the concrete, concrete SRSM is generally
considered to be volume contaminated. Concrete SRSM constitutes more than 90
percent of the total SRSM arising from decommissioning the population of U.S.
power reactors.
Finding 3.4. About 1 million metric tons of metallic SRSM and anywhere from
about 3.7 million metric tons to greater than 12 million metric tons of concrete
SRSM are projected to arise from cleanup and decommissioning of DOE facili-
ties during the coming 25 years. This quantity of metallic SRSM is comparable in
magnitude to the quantity of metallic SRSM estimated to arise from decommis-
sioning the population of U.S. power reactors and corresponds to only an addi-
tional 0.1 percent of the total obsolete steel scrap recycled in the United States
during the same 25-year period.
Finding 3.5. TENORM is generated in the United States at an annual rate of
about 2.3 million metric tons per year. The quantity of TENORM SRSM pre-
dicted to arise over the coming 25-year period is nearly 16 times larger than the
quantity of SRSM estimated to arise from decommissioning the population of
U.S. power reactors.
Representative terms from entire chapter:
radioactive materials
