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6.3 Longevity of Control
In Chapter 5 (Sec. 5.4) we discussed longevity of control and the
effects of natural forces and human activity on longevity. Although the
ultimate objective would be to assure control for as long as the material
is potentially hazardous, we cannot reasonably expect institutional control
to last for more than a few hundred years. Lasting effectiveness depends
on physical disposal methods, proper consideration of site conditions, and
verification of disposal performance over the short term. Beyond the
period control may be a reasonable expectation, continued control must be
assumed to rely on chance or natural events.
A review of estimated control costs (this chapter and Appendix B)
shows that they depend more on the specific methods than on the degree of
radon control. That is, the range of costs using different methods for a
given radon control level is greater than the range in costs for different
radon control levels. Generally, those methods are most costly which, if
they performed as expected, would provide control for the longest periods
of time. Therefore, the longevity objective may be the primary factor in
determining the actual cost of control.
Some of the tailings disposal methods discussed in Chapters 5 and 6
and Appendix B are expected to last much longer than others. Generally,
the thicker the cover, the longer control will be effective. Thin covers
of artificial materials can greatly reduce radon releases but are not
expected to last very long. Stabilizing a tailings pile's surface against
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wind and water erosion is a key factor in the longevity of control
effectiveness for disposal at or near the earth's surface. Stabilization
requires careful site selection and durable surface treatments to inhibit
erosion. Disposal in a suitable location deep underground appears, in
principle, to be an even more promising way of avoiding disruption of
tailings by natural events or people.
In general, below-grade disposal should be less subject to erosion
than disposal above-grade. Furthermore, since all the tailings piles at
inactive processing sites are now above-grade, disposing of them below-
grade generally implies choosing new locations. This would present
opportunities for finding particularly suitable sites. In practice,
however, site-specific conditions can blur these distinctions. At some
sites, above-grade disposal techniques may offer the stability more
characteristic of below-grade disposal.
The longevity of a control method is difficult to specify quanti-
tatively. We expect certain methods to last longer than others, but
experience with all control methods is quite limited, expecially
considering the time tailings will remain hazardous. We believe the
characteristic longevity we may expect for above-grade disposal is hundreds
to thousands of years, for below-grade disposal is thousands of years, and
for deep disposal tens of thousands of years or more. Potential hazards
will increase as control is partially or completely lost, so the benefits
of control depend directly on how long the controls will last. Since
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longevity can be described only broadly, it is not possible to directly
relate the costs of specific long-lasting control methods to estimates of
the adverse health effects they will avoid. However, the goal is to
isolate tailings for as long as may reasonably be done, and thereby avoid
future harm for at least that period. For this reason, disposal sites and
specific control methods should be selected with the primary emphasis on
the longevity of tailings isolation.
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6.4 Environmental Impacts of Control Actions
There will be adverse environmental impacts due to cleanup,
transportation, and final disposal of uranium mill tailings. Whenever the
tailings are disturbed in the cleanup process, by excavating, hauling,
etc., there is a potential for increased airborne particulates. Radon-222
releases might also be increased temporarily as tailings are uncovered or
piled in a new physical arrangement. Careful attention to dust control
will mitigate the airborne particulate problem. There might also be
increased erosion by surface runoff and other natural forces. Spillage of
tailings or other contaminated materials is probable, and good house-
keeping practices will be needed to assure they are cleaned up and not
spread around the environment.
Cleanup of contaminated land areas will require trucking material to
a disposal site, thereby increasing road traffic, dust, noise, fumes, and
the accident potential. Removal of a tailings pile to a new location will
incur similar risks. Disruption of vegetation at a new site, or when
obtaining material to cover the tailings, is an adverse impact. However,
these are temporary effects, since they occur only during the cleanup and
disposal operation. Compared to the long-term impact of uncontrolled
tailings, these temporary effects, if reduced as much as is practical,
could be considered negligible.
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6.5 Occupational Hazards
In addition to the temporary adverse environmental impact, there will
be hazards to workers who implement the tailings controls. Workers who
clean and move uranium tailings will have higher exposure to gamma
radiation and radioactive airborne particulates than most others in
earthmoving occupations. Usual health physics procedures to control
radiation exposures will have to be employed (HA Ip). Hazards from using
trucks and other earth moving equipment will be similar to those in any
large scale earth moving project. Again, these are temporary aspects of
the cleanup and disposal operation, and, with proper care, may be
negligible in comparison to the long-term impact of uncontrolled tailings.
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6.6 Economic Considerations at the Local Level
Somewhat offsetting the temporary adverse environmental impacts and
occupational hazards is the possibility of economic gains in the locality
of the mill tailings sites. If there is unemployment in the area, the
cleanup activities may provide temporary employment opportunities. There
may also be an increase in business activity in the local area. Con-
taminated land and structures may be made available to the local community
as a result of the cleanup program. However, under the terms of
Sec. 104(f)(2) of PL 95-60U, the disposal site will be licensed by the
NRC, which may limit or prohibit its public use. Since public funds
expended on tailings control will be unavailable for other uses, local
economic gains may be offset by dampening of other national economic
sectors.
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Reference for Chapter 6
(HA Ip) Hans, J.M., Jr., Burris, E., Gorsuch, T., "Radioactive Waste
Management at the Former Shiprock Uranium Mill Site,"
Environmental Protection Agency Technical Note (in preparation)
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7. CONSIDERATIONS FOR CLEANUP OF CONTAMINATED LAND AND BUILDINGS
7.1 Introduction
Land areas have been contaminated by wind- and water-borne tailings.
Tailings disposal will include disposal of some contaminated soils. If the
control method chosen for disposal of a tailings pile requires moving it,
then contaminated soil beneath the pile must also be disposed of.
Buildings have also been contaminated by wind- and water-borne
tailings, and by the deliberate use of tailings as fill under and around
*
the structures. Buildings that were once part of the mill operation are
also contaminated to various degrees.
This chapter considers information pertinent to setting standards for
cleanup of contaminated open land and buildings.
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7.2 Off-Site Contamination
In Sec. 3-3.3 we discussed the results of a study to determine the
specific locations of uranium mill tailings in communities near inactive
processing sites. Table 3-9 indicates that of the 7,583 radiation
anomalies (a radiation anomaly is a gamma radiation level higher than
normal) detected in the regions surveyed with the mobile gamma radiation
scanner, 1,319 of these are caused by mill tailings, 644 are due to a
radioactive source (including luminous dial alarm clocks and mined
uranium), 904 are due to naturally-occurring radioactivity, and the cause
of 4,716 anomalies is unknown.
These data do not include Grand Junction, Colorado, where large-scale
use of tailings occurred and a Federal/State remedial action program for
affected buildings is being conducted. In Mesa County, where Grand
Junction is located, over 25,000 locations had been screened to identify
areas of possible tailings use as of October 15, 1978 (GJ 79). More than
6,000 locations had some tailings on the property; the other, 19,000 did
not have any tailings. Of the locations with tailings, about 800 are
expected to receive remedial action, 200 more qualify for remedial action
but the property owners will not apply, and the remaining approximately
5,000 have radiation levels below the program criteria for remedial action.
In Mesa County there are also places where tailings were used in construc-
tion of sewer and water lines, streets, and other projects, which will be
eligible for remedial actions under PL 95-604.
7-2
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The extent of contamination near the inactive processing sites due to
erosion of tailings piles by wind and water was determined through gamma
radiation surveys. Table 3-10 summarizes the results. More than 5,000
acres were found to have gamma radiation levels exceeding the normal
background. The contaminated area defined by gamma radiation levels equal
to or greater than 10 uR/hr above background is more than 2,000 acres.
This figure does not include the areas of tailings piles, which is about
1,000 acres.
The seriousness of the off-site contamination depends, of course, on
the amount of contamination and the potential exposure to people. The
amount of land and number of buildings that will require cleanup will be
determined by the cleanup standards selected.
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7.3 Potential Hazards of Off-site Contamination
The greatest hazard from tailings on open lands is increased levels
of radon decay products in buildings. Exposure to direct gamma radiation
and contamination of drinking water and food may also occur, but generally
will be of less concern.
In Chapter 4 we discussed the health risk associated with radon decay
products. Their concentration in an existing or future building will
depend on the radium concentration in the soil under or adjacent to it.
However, so many other factors affect the indoor radon decay product
concentration that a useful correlation with the radium in soil is
difficult to establish. Nevertheless, Healy and Rogers (HE 78) analyzed
exposure pathways due to radium in soils, whether naturally-occurring or
as contamination. They argue that one might expect indoor radon decay
product concentrations of 0.01 WL for soils with radium concentrations of
1-3 pCi/gm to a depth of at least one meter. NRC estimates (NR 79) that
3-5 pCi/gm of radium can cause indoor concentrations of 0.01 WL. Although
both of these calculations are approximations, radium concentrations near
the lower end of these ranges correspond to common natural soil conditions.
Therefore, where indoor radon decay product concentrations are only
slightly elevated, radon sources other than tailings may be the dominant
causes, so remedial action for tailings may have little beneficial effect.
Furthermore, cleaning contaminated open land will not eliminate elevated
radon decay product levels in future buildings, but generally will reduce
their degree of occurrence.
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Tailings also emit gamma radiation, which can penetrate the body from
the outside. We expect the indoor radon decay product concentration
standards generally will be met by removing tailings from the building,
and this will eliminate any indoor gamma radiation problem. For some
buildings, however, complete tailings removal may not be a practical means
of lowering the indoor radon decay product concentration, more for
engineering reasons than for cost. Alternate methods, such as air
cleaning, improving ventilation, or applying sealants to the walls and
floors are available. If these are used, standards will be needed to
limit gamma radiation exposure of the occupants.
Natural or contaminated soils with radium concentrations of 5 pCi/gm
through several feet down can also give exposure rates from gamma radiation
of about 80 mR/yr (NC 76). Exposure rates are proportionately higher or
lower for other concentrations, and decrease as the layer of radium-
containing material becomes thinner, or is covered over by other materials.
The potential for causing elevated indoor radon decay product levels in
future buildings on such soils also depends on these factors. Therefore,
cleanup standards for open land should take account of both the
concentration and the thickness of the contamination.
Each gram of natural uranium contains 330,000 pCi of U-238 and
15,000 pCi of U-235. Because it appears in relatively small proportion,
U-235 and its radioactive decay products usually may be ignored in
evaluating the hazard of uranium tailings. The dominant hazard from
7-5
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tailings of the usual composition is due to decay products of U-238,
including radium-226 and its decay products. Other radioactive substances
in the tailings will ordinarily pose much less risk to health than that
from radium-226.
The total protection provided by a standard based on radium-226
depends on the extent to which radium has been separated from other radio-
active substances, such as thorium and the U-235 decay products, during ore
processing. If significant separation occurs, radium-226 concentration in
the residual material may not be an adequate measure of the radiation
hazard. For example, thorium separates from radium in uranium mills using
the acid leach process. Although thorium-230 and radium-226 occur in ore
in about equal amounts of radioactivity, thorium compounds are more soluble
in acid. Therefore, thorium radioactivity concentrations in the wastewater
can be thousands of times higher than for radium, and more thorium may then
seep through the pile to the soil below (RA 78). However, chemical inter-
action of thorium with the soils is expected to retard further movement
(GS Ip).
At least one of the processing sites covered under Public Law 95-604
(Canonsburg, Pa.) may have tailings containing higher than usual
proportions of U-235 decay products. Although little is known about the
environmental pathways and biological effects of these radionuclides,
site-specific information on their concentrations suggests they are not
likely to be a determining factor in clean up decisions (DO 78). This is
because the U-238 decay products are present in greater amounts.
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7.4 Remedial Actions and Costs
The only permanent remedial action that will avoid the hazards from
contaminated land and buildings would be to remove uranium mill tailings
from under and around buildings, and from open land, and to dispose of
them in the tailings pile. The costs and complexity of tailings removal
from buildings depends on the amount of tailings and their location
relative to the structure. For example, tailings used as backfill around
the outside of a foundation can be removed easily at a relatively low
cost. On the other hand, removing tailings from under a floor or
foundation involves the more complex and costly procedure of breaking up
concrete to reach the tailings. In 1972, Congress enacted PL 92-314,
authorizing a remedial action program for buildings in Grand Junction,
Colorado, which were affected by that community's extensive use of
tailings in construction. Experience gained through seven years of that
program illustrates the remedial action costs that may be incurred for
similar situations in other places under PL 95-604. In the Grand Junction
remedial action program the average cost to treat a residential structure
has been about $13,500, and ranged from $540 to $41,000 (GJ 79).
Remediation for commercial structures averaged about $3^,500, with a range
of $6,600 to $107,000. Schools averaged about $92,900, and ranged from
$19,000 to $500,000. The total cost in Grand Junction through September
30, 1978, was almost $7,000,000. It is estimated that the final total
cost for about 800 buildings may be about $17,000,000 (GJ 79).
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For the lands and buildings included in the Phase II study, estimated
cleanup costs for off-site contamination were about $7,000,000 (FB 76-78),
and for the Canonsburg, PA., area were about $3,400,000 (FB 79). Because
the Phase II estimates were based on interim cleanup criteria (for doing
an engineering assessment), they may indicate only the approximate costs
under a final standard.
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7.5 Previous Standards for Indoor Radon Decay Product Concentration
Government agencies of the United States and Canada have previously
published remedial action criteria for radon decay product concentrations
in buildings.
The U.S. Surgeon General's 1970 remedial action guidance for Grand
Junction, Colorado applies to buildings on or containing uranium mill
tailings (PE 70). EPA's guidance to the State of Florida applies to
buildings on radium-bearing phosphate lands (FR 4*0. Each set of guides
has three levels: radon decay product concentrations above the high level
require action; those below the low level do not; local factors determine
the action required for buildings where the concentration is between these
levels.
The Surgeon General's Guides are implemented in the Department of
Energy's regulations for remedial action at Grand Junction, Colorado
(10 CFR 712). In effect, they adopt the lower level as an action level
for schools and residences, and the mid-point between the lower and upper
levels as an action level for other buildings. This difference in action
levels recognizes the desired added protection for children and occupancy
period differences for residences and commercial buildings. For radon
decay product concentrations these action levels are 0.01 WL and 0.03 WL,
respectively, above background. The average background indoor radon decay
product concentration determined for use in the Grand Junction remedial
action program is 0.007 WL.
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The Canadian cleanup criteria (AE 77) and the EPA recommendations for
residences on phosphate lands in Florida require remedial action for
indoor radon decay product concentrations greater than 0.02 WL (including
background). The EPA guidance further recommends that concentrations
below 0.02 WL be reduced as low as is reasonably achievable. Reductions
below 0.005 WL above the normal average background (for nearby lands in
Florida) of 0.004 WL are not generally justified in the Florida phosphate
lands. In effect, then, for Florida EPA has recommended: remedial action
in all cases above 0.02 WL: action generally unjustified at concentrations
less than 0.009 WL; and for intermediate levels, action is left to the
judgment of local officials.
In Chapter 3 we discussed surveys conducted to find buildings which
may be affected by tailings for which remedial actions may be conducted
under PL 95-604. These surveys show a variety of affected structures,
whose elevated radiation levels have several different causes. The total
number of buildings that will be eligible under PL 95-604 is not fully
established, but we believe they are fewer or comparable in number to
those in Grand Junction.
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7.6 Normal Indoor Radon Decay Product Concentrations
The indoor radon decay product concentration of a building affected
by tailings is the sum of contributions from tailings and from the natural
environment. These contributions cannot be distinguished from one
another. As we shall discuss in Section 8.2, knowledge of the
characteristics of radon decay product concentrations in normal buildings
is very useful in deciding the best form for a remedial action standard,
and in choosing a practical action level.
The most complete studies of normal indoor radon decay product
concentrations in the United States were performed on buildings in Grand
Junction, Colorado (PE 77), New Jersey and New York (GE 78), and Florida
(PL 78). The samples and measurement techniques of these studies are not
exactly comparable, however. The New Jersey-New York buildings studied
were residences, mostly single-family, one or two story buildings. The
Grand Junction sample was mainly houses, about half of which had basements
(CO 79). The reported Grand Junction data are for the lowest "habitable
portion" of the building. The Florida sample is single-family houses
without basements.
Some results from these studies are summarized in Table 7-1. In all
cases, the reported concentrations are the average of measurements taken
over a year. The data indicate wide variations in normal indoor radon
decay product concentrations within each sample, even for a relatively
uniform sample of buildings. Furthermore, the New Jersey-New York data
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show that ground-level concentrations are about half of those in the
basement. (An unpublished analysis of the Grand Junction data shows a
similar effect (CO 79).)
Many buildings in the northeastern and western United States, where
the sites covered under PL 95-604 predominantly are located, have
basements. For these buildings especially, the most important conclusions
we draw from these studies are the following:
1. Normal indoor radon decay product concentrations are very
variable.
2. Concentrations greater than 0.01 WL in a useable part of a normal
building are common.
3. Though less common, it is not rare for normal concentrations to
exceed 0.015 WL.
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TABLE 7-1
Average^Annual Radon Decay Product Concentrations
in Normal Buildings
Grand Junction, Colorado(a)
Sample: 29 buildings, mostly houses, about half with basements.
Range: 0.002-0.017 WL
Median: 0.007 WL
Above 0.01 WL: 30$
Above 0.015 WL: 10$ (approx.)
New Jersey-New York(b)
Sample: 21 houses, mostly single-family with full basements.
Cellar First Floor
Range: 0.0017 - 0.027 WL 0.0017 - 0.013 WL
Median: 0.008 WL 0.004 WL
Above 0.01 WL: 40$ 8$
Above 0.015 WL: 20$ 2%
Florida(c)
Sample: 28 single-family residences, without basements.
Range: 0.001 - 0.012 WL
Median: 0.0035 WL
Above 0.01 WL: 3$
Above 0.015 WL: 0$
(^References (PE 77) and (CO 79).
(^Reference (GE 78).
(^Reference (FL 78).
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7.7 Practicality of Alternative Remedial Action Standards for Buildings
We may use experience in the Grand Junction program to estimate the
scope of a cleanup program for tailings under alternative remedial action
criteria. Table 7-2 gives the Grand Junction program's results (CO 79)
for buildings having tailings for which radon decay product measurements
have been made. For residences and schools (R/S), the remedial action
level is 0.01 WL above background. Among the 463 R/S sampled, 217 were
found eligible for remedial action. If the action level had been 0.005 WL
above background, the eligible number would have been 61 more, an increase
of 2Q%. Table 7-2 also shows that some R/S for which remedial actions
have been performed have not yet been brought below the action level. Had
the action level been 0.005 instead of 0.01 WL above background, an
additional 51 R/S would need further remedial work. Table 7-2 shows 40 or
52 additional buildings other than R/S would have been eligible if the
action level for them had been 0.01 WL or 0.005 WL above background,
respectively. This is an increase of 114$ or 149?, respectively, in the
program for that category of buildings. The table also shows that under
the lower action levels additional work would be needed for 17 to 26 of
the buildings other than R/S on which remedial action has already been
performed.
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TABLE 7-2
Experience with Grand Junction Remedial Action Program
Non-Eligible
Residences and Schools
Other
Total
246
76
No. Above
0.01WL + Background
0
40
No. Between
0.005WL and 0.01WL
Above Background
61
12
Post-remedial
Residences and Schools 217
Other 35
60(e)
17
51
9
(^Modified from reference (CO 79).
(b'Table entries are numbers of buildings having tailings for which
radon decay product measurements have been made.
^°'Buildings for which remedial actions have not been completed.
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References for Chapter 7
(AE 77) Atomic Energy Control Board of Canada, "Criteria for Radioactive
Cleanup in Canada," Information Bulletin 77-2, April 7, 1977.
(CO 79) Colorado Department of Health, October 3, 1979, Letter from
A. Harold Langner, Jr., and subsequent conversations.
(DO 78) Department of Energy, Report No. DOE/EV-0005/3, April 1978.
(FB 76-78) Ford, Bacon, and Davis, Utah, Inc., "Phase II-Title 1,
Engineering Assessment of Inactive Uranium Mill Tailings,"
20 contract reports for Department of Energy Contract
No. E(05-1)-1658, 1976-1978.
(FB 79) Ford, Bacon, and Davis, Utah, Inc., July 1979, "Engineering
Evaluation of the Former Vitro Rare Metal Plant, Canonsburg,
Pennsylvania" and "Engineering Evaluation of the Pennsylvania
Railroad Landfill Site, Burrell Township, Pennsylvania."
(FL 78) Florida Department of Health and Rehabilitative Services, "Study
of Radon Daughter Concentrations in Structures in Polk and
Hillsborough Counties," January 1978.
(FR 44) Federal Register 44. p 38664-38670, July 2, 1979.
(GE 78) George, A.C., and Breslin, A.J., "The Distribution of Ambient
Radon and Radon Daughters in Residential Buildings in the New
Jersey-New York Area," presented at the Symposium on the Natural
Radiation in the Environment III, Houston, Texas, April 1978.
(GJ 79) Grand Junction Office, February 1979, "Progress Report on the
Grand Junction Uranium Mill Tailings Remedial Action Program,"
U.S. Department of Energy Report DOE/EV-0033-
(GS Ip) U.S. Geological Survey, In press, "Uranium Mill Tailings and the
Technologically Enhanced Natural Radiation Environment," Circular
814.
(HE 78) Healy, J.W., and Rodgers, J.C., October 1978, "A Preliminary
Study of Radium-Contaminated Soils," Las Alamos Scientific
Laboratory Report No. LA-7391-Ms.
(NC 76) National Council on Radiation Protection and Measurements,
December 1976, "Environmental RAdiation Measurements," NCRP
Report No. 50.
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(NR 79) U.S. Nuclear Regulatory Commission, April 1979, "Generic
Environmental Impact Statement on Uranium Milling," Volume II,
App. J, NUREG-0511.
(PE 70) Letter by Paul J. Peterson, Acting Surgeon General to Dr. R.L.
Cleere, Executive Director, Colorado State Department of Health,
July 1970.
(PE 77) Peterson, Bruce H., "Background Working Levels and the Remedial
Action Guidelines," in the Proceedings of a Radon Workshop,
Department of Energy Report No. HASL-325, July 1977.
(RA 78) Rahn, P.H., and Mabes, D.L., "Seepage from Uranium Tailings Ponds
and its Impact on Ground Water," Proceedings of the Seminar on
Management, Stabilization, and Environmental Impact of Uranium
Mill Tailings, July 1978, the OECD Nuclear Energy Agency.
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8. SELECTION OF PROPOSED STANDARDS AMONG ALTERNATIVES
In PL 95-604, the Congress stated its findings that tailings "...may
pose a potential and significant radiation health hazard to the public,
...and...that every reasonable effort should be made to provide for
stabilization, disposal, and control in a safe and environmentally sound
manner of such tailings in order to prevent or minimize radon diffusion
into the environment and to prevent or minimize other environmental
hazards from such tailings." The Environmental Protection Agency was
directed by Congress to set "...standards of general application for the
protection of the public health, safety, and the environment..." for such
materials. The legislative record also shows that Congress intended that
these standards not be site-specific.
The Committee report on the Uranium Mill Tailings Radiation Control
Act expressed the intention that the technologies used for remedial
actions should not be effective for only a short period of time. "The
Committee does not want to visit this problem again with additional aid.
The remedial action must be done right the first time," it stated (House
of Representatives Report 95-1480, Part 2).
Our proposed standards are meant to ensure a long-lasting solution.
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8.1 Disposal Standards
Our analysis of the health effects from tailings piles shows they are
due, in the main, to radon emissions into air. In addition, environmental
contamination could occur if toxic chemicals from tailings entered surface
or underground water, although this depends strongly on individual site
characteristics.
8.1.1 Radon Standard
From our analysis of health effects of tailings piles we conclude:
a. Radon and its short-lived decay products constitute the dominant
radiation hazard from untreated uranium mill tailings piles on local,
regional, and national scales. Effects of long-lived radon decay products,
of windblown tailings, and of direct gamma radiation from the piles are
much less significant.
b. Individuals near a pile bear much higher radiation risks than
those far away. For example, we estimate that individuals living
continuously one mile from a large hypothetical pile would have over 200
times as great a chance of fatal lung cancer (7 in 10,000 versus 3 in
1,000,000) caused by radon decay products from the pile as persons living
20 miles away (Table 4-2). People even closer to some of the piles at
inactive processing sites bear increased lifetime lung cancer risks as
high as 4 chances in 100 (Table 4-1).
8-2
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c. The total number of cancer deaths estimated to be induced by a
uranium mill tailings pile depends strongly on the size and distribution
of the local population.
d. All the piles taken together may cause about 40 to 90 deaths per
century among persons living 50 miles or more away from a pile. When
local and regional rates are added to these, the total national effect of
all the piles is estimated as 170-240 premature deaths per century; i.e.,
an annual rate of about 2 deaths.
These estimates are based upon current population sizes and
geographical distributions. Overall increases in national population
would raise the estimated national effects in approximate proportion.
Development of new population centers near currently remote piles, and
substantial growth of cities already near one, could multiply local and
regional estimates several fold.
Unless radon emissions from the tailings piles covered under Title I
of PL 95-604 are greatly reduced, they might prematurely kill about 200
people per century over the indefinite future. Even for piles now remote
from population centers, equity for people living nearby and the
possibility of future development near the sites argue for control
measures. A reasonable effort to prevent or minimize radon emissions from
piles is required under PL 95-604.
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Methods for controlling radon emissions from tailings piles are
available. The most straightforward methods involve either burying the
piles or covering them with appropriate combinations and thicknesses of
soils, and with erosion-resistant surfaces. We believe the basic capabil-
ities of these methods, although largely untested, are understood. Other
methods may also be useful, as described in Chapter 5 and Appendix B, and
in NEC's GEIS for Uranium Milling (NR 79).
From several perspectives, we find it reasonable to reduce radon
emission rates from tailings at inactive processing sites from their
current values of several hundred pCi/m^-sec to a range more character-
istic of ordinary land. Typical natural emission rates are from 0.5 to
p
1 pCi/m -sec, with variations up to several times these values not
unusual (NR 79).
We considered setting a radon release standard at higher or lower
levels. Higher levels, say 10-40 pCi/m2-sec, appear unjustified, because
emission rates of that size can be lowered for moderate incremental costs.
With such elevated radon emissions, the probable need for land-use restric-
tions would place a continuing administrative burden on future generations.
We also find almost total control of radon release from the tailings
unjustified. Incremental costs for achieving emission rates lower than
1 pCi/m -sec rise rapidly relative to radon emission reduction and any
health benefits that might be achieved. Land-use restrictions because of
8-4
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radon release are unlikely to be needed for levels near 1 pCi/m^-sec.
We have not found any administrative or esthetic advantages in further
reductions.
Having decided to control radon emission to a range characteristic of
ordinary land, we next consider the form and numerical values of the
standard. Three quantities will be considered as the basic unit of the
standard: the radon emission per unit area per unit time ("flux"), the
total radon release rate, or the dose or exposure of actual or
hypothetical individuals or populations.
A dose or exposure standard is rejected as cumbersome to implement,
with no compensating advantages except its direct relationship to risk. A
pre-eminent purpose of the standard is to guide the design of disposal
systems. A dose or exposure standard would introduce avoidable
uncertainty in this process, because flux must be known before these other
quantities can be estimated.
Limiting the total radon release rate from a site fails to take
account of the great differences in radioactivity among the piles (see
Table 3-4). Applying a single limit on total radon release to all piles
could place unreasonable burdens on the disposal designs. A flux limit,
^However, PL 95-604 provides that after remedial actions are
completed, the tailings will be in Federal custody under license by the
Nuclear Regulatory Commission.
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however, may readily be applied uniformly to all sites. Flux is also the
most meaningful quantity for comparing the emission of the site with that
of normal land. Since radon release rates vary continuously as climate
factors change, however, the standard should address the average flux over
a suitable time (annual).
We have concluded that the numerical limit on pile flux, following
disposal, should be chosen in a range of about 0.5 to 2.0 pCi/m^-sec.
When added to the flux of a normal earth covering, the disposal site flux
would still be within a normal range.1 The risk for people not directly
on the disposal site is small enough to be a minor factor in choosing a
standard within this range (98% or more of their radon exposure comes from
other sources (NR 79)).
Disposal sites generally will be large enough to build a small
community upon. It appears unlikely, however, that a combination of
emission, residency, and construction factors would materialize that would
lead to a public health problem under a standard in the range we are
considering. The incremental risk associated with the choice of a control
level for radon flux appears small enough so that other factors should
also be considered.
1A covering of average soil will contribute an additional 0.5 to
1.0
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Figure 5-1 shows that, in a flux region near 1 pCi/m -sec, large
increases in covering thickness are needed to further reduce radon emission
when a 99% reduction has already been achieved. These curves are based on
theory and laboratory tests; there has been no opportunity to test them
against full-scale field experience. If soil covering should be less effi-
cient in controlling radon than the curves indicate, achieving a standard
at the low end of the radon emission range could be much more difficult
and expensive than we estimate. Yet, the health benefit so gained would be
P
marginal. We therefore propose an allowed tailings flux of 2 pCi/m -sec
rather than a slightly lower figure to allow for more technical flexibility
in implementing the standard.
We believe our approach is appropriate for a new and large scale
undertaking. Typically, the proposed standard would reduce radon emissions
and their effects by 99%- Measures which will cut down radon emissions
this much for 1000 years (see Section 8.1.5) will also eliminate blown
tailings and excess gamma radiation. Therefore, implementing the radon
control standard will virtually eliminate all the potential hazards except
water pollution.
8.1.2 Ground Water Standard
Since most of the inactive sites are in dry climates, much of the
water that may ever infiltrate them has probably already done so during
active operation of the mill. This probably is not true for all sites,
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and standards for protecting ground water after disposal of the tailings
are needed.
The proposed ground water protection standards for uranium mill
tailings are patterned after criteria adopted for solid wastes (FR 79)
under Sec. 1(004 of the Resources Conservation and Recovery Act (RCRA). EPA
deems violation of these criteria in disposing of the solid wastes to which
they apply to pose a reasonable probability of adverse effects on health or
the environment. Later, we discuss the possibility of remedial actions for
water contamination that could occur as a result of contaminants released
from tailings prior to disposal.
Under our proposed ground water standard, tailings may not contaminate
an underground drinking water source beyond a specified distance. Contam-
ination is defined here as occuring when, after disposal, a tailings pile
causes the concentrations of certain pollutants in the ground water to
either (1) exceed the maximum contaminant level specified for that pollu-
tant, or (2) increase, where the background concentration of the pollutant
already exceeds the applicable maximum contaminant level. An underground
drinking water source is an aquifer currently supplying drinking water for
human consumption or an aquifer in which the concentration of total
dissolved solids is less than 10,000 milligrams per liter (FR 79a).
The proposed ground water protection standards could be considered too
strict if implementing them would be unreasonably costly, or if they would
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be impossible to apply. Available information suggests our proposals are
practical. The following sections discuss alternative approaches to
setting the standard, and describe the reasons for choosing the proposed
standards:
Approach to Ground Water Protection
These standards are conditions for disposal of uranium mill tailings,
not ambient water quality criteria. We have concluded that disposal of
tailings should not degrade ground water beyond levels established to
protect human health. We recognize that ground water quality is important
for other purposes (e.g., for irrigation of plants, for its effect on
fragile ecosystems). Differing standards may be appropriate to protect its
usefulness for these other purposes. However, at this time, we have
decided to define "contamination" in terms of the water's use as a drinking
water source. We believe that the prevention of adverse human health
effects from direct consumption of ground water should be the first among
several objectives in protecting ground water quality. Moreover, EPA has
developed standards for drinking water but has not established standards
for other uses.
Where maximum contaminant levels in an aquifer are already exceeded,
due to other conditions or actions which do not involve a tailings pile,
tailings disposal should not be allowed to increase the risk to present or
future users of the aquifer. Future users of the aquifer will not be
protected unless such an approach is taken.
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Contaminants of Concern
Contaminant levels in the National Interim Primary Drinking Water
Regulations (NIPDWR) provide the best current guidance of adequate protec-
tion levels for drinking water. However, we also considered whether all
the appropriate substances in tailings are covered in the NIPDWR, and
whether some contaminants which are covered may be superfluous.
Except for fluorides, all the inorganic chemicals listed in the NIPDWR
have been reported as present in tailings. However, uranium mill tailings
are not significant sources of organic chemicals, microbiological
contamination, or man-made radioactivity, so these categories of the
NIPDWR need not apply to tailings disposal.
Other substances which may be harmful to human health were not included
in the NIPDWR due to their relatively rare occurrence in drinking water
systems, the lack of analytical methods, the high costs of monitoring, or
the lack of toxicity data. Several such substances are present in leachate
from tailings. We have reviewed these substances and have included two —
molybdenum and uranium — in our proposed standard, because of the serious-
ness of their toxic effects on humans, animals, or plants, their abundance
in the tailings, and their expected environmental mobility. The proposed
concentration limit for molybdenum was chosen as appropriate limit for the
protection of human health, in accordance with the recommendations of a
recent report to EPA (CH 79). The proposed standard for uranium limits the
bone cancer risk to about the same degree as the NIPDWR does for radium.
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We have also considered the contaminants addressed by the National
Secondary Drinking Water Regulations (NSDWR). The NSDWR (40 CFR 143)
represent the Agency's best judgment of the standards necessary to protect
underground drinking water supplies from adverse odor, taste, color and
other aesthetic changes that would make the water unfit for human consump-
tion. However, we have decided not to include the contaminants identified
in the NSDWR in the proposed standards. The list of contaminants we are
including covers the most hazardous substances. It also covers many
different chemical forms. Conditions under which these toxic substances
are well-controlled are likely to also control other substances. Since we
expect scientific analyses and predictions based upon them to be the
primary means of demonstrating compliance with the standard, we do not
wish to make that task considerably more complicated by including
nonessential requirements.
Two other sets of pollutants were considered for inclusion in these
criteria: those covered in the "Quality Criteria for Water" (EP 76) and the
list of toxic pollutants referenced in Section 307(a)(1) of the Clean Water
Act, as amended. The publication "Quality Criteria for Water" recommends
levels for water quality in accord with the objectives in Section 101(a)
and the requirements of Section 304(a) of the Clean Water Act. Its primary
purpose is to recommend levels for surface water quality that will provide
for the protection and propagation of fish and other aquatic life and for
recreation. Although recommended levels are also presented for domestic
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water supply, and for agricultural and industrial use, ground water was
not a major consideration.
"Quality Criteria for Water" lists most of the substances in Parts
and 143- Several of the additional listings are only of interest in
surface water protection, such as definitions of mixing zones, temperature,
and amount of suspended solids. While several health related substances
that could be present in tailings leachate are listed, the recommended
limits are specified for aquatic life protection and are not appropriate
for ground water. Furthermore, the recommended limits were written to be
guidance in developing standards, not to be used as standards themselves.
Therefore, we decided that this list was inappropriate for these standards.
Levels of Contamination
Tailings "contaminate" ground water if they introduce a substance
that would cause:
(a) The concentration of that substance in the ground water to
exceed specified maximum contaminant levels, or;
(b) An increase in the concentration of that substance in the ground
water where the existing concentration of that substance exceeds the
specified maximum contaminant levels.
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We intend the first part of the above definition to protect water
that can be used as drinking water without treatment under current
regulations. The second part is intended to protect ground water already
at or above the maximum contaminant level by preventing increases in
contaminant concentrations.
We considered several possible reasons for adopting more lenient
standards than the proposed ones: (a) that the increased disposal cost
might be greater than the value of the threatened resource; (b) that the
more efficient approach would be to remove some substances from the water
supply by treatment after contamination; and (c) that some of the allowable
levels are commonly exceeded in ambient or native ground water, which
effectively results in a nondegradation standard for those aquifers.
There is no doubt that some people will continue to consume ground
water that has not been treated. That portion of the public, including
those in the future, should be protected from adverse effects caused by
tailings leachate entering their drinking water to at least the extent we
currently protect the general public. In some situations protecting the
public will require nondegradation of an aquifer. We are not required to
balance disposal costs against the "value" of ground water resources, nor
can the value of these resources be determined for an indefinite future.
We believe the proposed standards are a reasonable approach to ground
water protection, and that more lenient standards are not preferable.
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Reasons we considered for adopting more stringent limits include:
(a) tailings disposal is but one of several sources of ground water contam-
ination, and each source contributes to the overall rise in contaminant
levels; (b) future research may find that lower levels are necessary to
adequately protect health; (c) some agricultural, industrial and other
important uses of ground water may be impaired; (d) since ground water is
often consumed without treatment, more stringent limits would require less
reliance on programs to monitor and to require treatment before domestic
usage.
The proposed standard does recognize that an aquifer may be polluted
by several sources. Where existing ground water quality levels exceed the
maximum contamination limits, tailings disposal may not degrade ground
water quality at all. Based on current knowledge of human toxicity, the
proposed standards are adequately protective. As discussed earlier, we do
not have the scientific basis for setting stricter standards designed to
protect ground water for all nondrinking purposes. No matter what the
standard, the need for monitoring must be determined on a case-by-case
basis, and it seems doubtful that differing standards would change that
need.
Where the Standard is Applied
Another issue regarding ground water protection is where the standard
should be applied (i.e., at what point in the aquifer does contamination
from tailings constitute noncompliance). The places we considered are at
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the site boundary, at the waste boundary, or at some specified distance
from the waste.
In the long-term viewpoint appropriate for uranium tailings, the
concept of a site boundary should play a minor role because it only
distinguishes areas a responsible party controls from areas where the
general public may be affected. Long after disposal, however, the size of
the region that may be affected is much more significant.
Applying the standard to the waste boundary would minimize the
affected area. The tailings at inactive processing sites have to some
extent merged with their immediate surroundings, so the waste boundary may
be hard to define. More significantly, a standard applied so near the
waste may be difficult to meet at some otherwise adequate, existing sites.
Where only local contamination might occur, the cost of liners and
re-siting appears to be unjustified. To avoid these higher costs with
their small benefit, a strict standard should apply only beyond some
distance. We arbitrarily propose this distance to be 1.0 kilometer from
the smallest practical boundary of the waste. A smaller distance of appli-
cation might not serve the intended purpose of avoiding large expeditures
for very little gain, and we believe a much larger distance would not be
sufficiently protective. However, if tailings are moved to a new disposal
site, for whatever reason, then new opportunities for site selection and
preparation become available. For new sites we choose the place of appli-
cation as 0.1 kilometer from the waste boundary. In effect, this is as
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protective as choosing it at the waste boundary, while allowing some
benefit from sorption and dilution in the ground, in case small leaks
occur.
Underground Drinking Water Source
The choice of the 10,000 mg/1 total dissolved solids measure for
usable aquifers follows the Agency's general policy that ground water
resources below that concentration be protected for possible use as
drinking water sources. This policy is based on the Safe Drinking Water
Act and its legislative history, which reflects clear Congressional intent
that aquifers in that class deserve protection.
8.1.3. Surface Water Protection
We also have considered the need for surface water protection
standards. Wind, rain, and floods can carry tailings into rivers, lakes,
and reservoirs. Pollutants may also seep out of piles and contaminate sur-
face waters. We believe the standards should limit the effects of these
processes on surface water quality. We expect that implementing the radon
emission limits and the ground water protection requirements will greatly
reduce contamination of surface water. A pile with severely restricted
radon releases will not be able to release particulates to wind or water.
Similarly, the ground water protection requirements imply limited water
flow through the pile, which limits flow to the surface as well as under
the ground. Thus, the radon emission and ground water standards will
provide adequate protection for surface water, and explicit standards may
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not be necessary. However, to assure adequate protection, we propose to
require that surface water not be degraded by tailings after disposal of
the piles. This means that disposal methods should prevent tailings from
increasing the concentration of any substances in surface water.
We believe it will be practical to satisfy virtually any strict
surface water protection standard. Because of this, we considered
requiring that there be no releases of pollutants to surface water.
However, this may be more difficult to implement than the selected
standard, since it would require showing that not even microscopic
releases will occur. Our chosen standard requires any pollutant streams
from the tailings to have lower concentration than the surface water they
may enter. The standard applies to all pollutants from tailings, however,
and some of them are certainly present only in very low concentrations in
surface water. Therefore, satisfying the standard will require strict
limits on releases of at least these latter substances. In practice, we
expect the means used to inhibit pollution of surface water by substances
which are already present in low concentrations to also restrain the
movement of most other pollutants. Therefore, we expect the standard to
be very protective of surface water.
We have chosen to apply the standard to "navigable waters" as defined
in an EPA Federal Register notice (44 F.R. 32901, June 7, 1979). This
definition was adopted for EPA's regulations under the National Pollutant
Discharge Elimination System, 40 CFR 122.3(t). In essence, it includes
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all surface waters which the public may traverse, enter, or draw food from.
However, there is no formal relationship between EPA's standards under
PL 95-604 and regulations under the National Pollutant Discharge
Elimination System; either may be changed without affecting the other.
8.1.4 Remedial Action for Existing Water Contamination
We have considered whether remedial action standards should be set for
existing and future contamination caused by past releases from the tailings
piles. We conclude that a general requirement to perform remedial actions
is not feasible, as there are no practical methods which will generally
work. However, we urge the implementing agencies to study any prospective
contamination, so appropriate restrictions on using water may be
established where they are needed. We also believe that site-specific
consideration should be given to performing practical remedial actions.
Since there are no generally applicable remedial methods, however, our
standards apply only to contaminants leaving the tailings after disposal
is completed.
8.1.5 Period of Application of Disposal Standards
The hazards of uranium mill tailings will persist indefinitely.
Through PL 95-604, Congress intended "every reasonable effort" to be made
to provide long-term public protection from these hazards. Under this
criterion, we propose requiring a reasonable expectation that the radon
emission and water protection standards for disposal will be satisfied for
at least 1000 years.
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Any choice of a suitable time period is partly arbitrary, as there
are no rules or precedents to guide the decision. Neither does scientific
analysis point uniquely to one period over another.
We have concluded that uranium mill tailings standards which apply for
periods as long as 10,000 to 100,000 years would be impractical. Providing
reasonable expectation of compliance with the standards over such long
periods, if possible at all for tailings, could be done only if they were
buried several hundred feet or more beneath the surface. During such long
time periods, climates change markedly and land surfaces may be denuded,
severely uplifted, or otherwise considerably transformed. Deep below the
surface severe changes are likely to be more gradual and predictable. For
reasons described earlier, the practicability of deep burial of uranium
tailings is uncertain. Yet, if strict standards were to apply for as long
as 10,000 years or more, no other disposal method would seem possible.
With tailings at or near the earth's surface, it appears feasible to
meet the standards for 1000 years or more. The primary threat during this
period is flooding. Methods of protecting tailings against floods and
other natural disruptions appear to be available. However, these methods
may not be applicable at every existing inactive site; some piles might
have to be moved for long-term flood protection, for example.
Standards applying for a period shorter than 1000 years would be
easier to satisfy, and might result in some cost savings. We judge the
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savings would be small, unless the period of application were only a few
hundred years.
The choice of a 1000-year period of application results from
practical considerations. We believe 1000 years meets the congres-
sional criterion of a reasonable effort to control these materials. A
1000-year standard does not mean our concern for the future is limited,
but does reflect our judgment that the disposal standards must be
practical. Technically and economically reasonable disposal methods may,
in some instances, be expected to protect for longer than 1000 years.
However, to generally require this is unreasonable, we believe, based on
existing knowledge of control methods and natural processes.
The disposal standards could be viewed as performance standards,
stating conditions to be satisfied without addressing the means. Compli-
ance could be verified by field observations (monitoring), and assured
through maintenance. More fundamentally, they are design standards. The
standards are the minimum requirements for the physical performance of a
disposal system over the full period of their application. Since the
standards apply for at least 1000 years, we believe institutional methods
involving maintenance and monitoring are useful adjuncts to an adequate
disposal system, but they should not replace physical long-term disposal
methods. The "reasonable expectation" for meeting the limits specified in
the standards will be established by considering the physical properties
of the disposal system, not by relying on institutional methods.
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8.2 Cleanup Standards
8.2.1 Open Lands
The proposed standard requires that for any open land contaminated
with tailings, the average radium concentration in any 5 centimeter
thickness shall not be more than 5 pCi/gm after cleanup. These conditions
provide a high degree of protection from tailings at inactive uranium
processing sites, and are not unreasonably burdensome to implement. The
protection achieved will often be greater than is apparent from the
standard, since the radium concentration of any material not removed will
often decrease sharply with depth. After the required cleanup, such a
site will be little more hazardous than a similar area which never had a
tailings pile.
Locating contaminated soils with concentrations less than 5 pCi/gm
would require extensive surveys and lengthy measurement procedures.
Increasingly large land areas would need to be stripped in order to lower
the radioactivity much below 5 pCi/gm. Doing this would provide very
little gain in health protection, since such slightly contaminated soils
are usually thin layers containing little total radium. Therefore, in
order to keep sampling costs within reason, and to avoid having to clean
large areas which contain little radioactivity, the proposed final
standard requires that for any open land contaminated with tailings, the
average radium concentration shall not be more than 5 pCi/gm after
cleanup. The contamination which remains after such cleanup will have
less than 5 times the radon release of average soils. It could also cause
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a gamma radiation dose of less than 80 millirad per year to a person who
spends 100 percent of the time outdoors on the site. These levels of
radon emission and gamma radiation are within the variations that occur in
undisturbed land areas. We believe that the actual radon and gamma ray
levels after cleanup will usually be much less than the maximum possible
under these standards.
For contaminated material located more than 1 foot beneath the surface
of open land, our proposed standard requires cleanup if the average radium
concentration over any 15 cm thickness is greater than 5 pCi/gm. Practical
measurement instruments could not find buried material of this concentra-
tion in any thinner layer. We expect this standard for buried material
will mostly apply to defining the edges of buried tailings deposits,
because the radium concentration in tailings is usually much higher than
5 pCi/gm.
In most cases, concentrations a few times higher than the proposed
standard allows would cause only a slight increase in risk. Since concen-
tration usually declines rapidly with depth, even a standard requiring
removal of material until the radium concentration level reached 10 or
20 pCi/gm would be protective. Unusual distributions of radium would be
much more significant, however, and areas with 5-20 pCi/gm are clearly
above ordinary background levels.
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Surveys at inactive processing sites indicate that it should cost
little more to implement the proposed standard than one permitting levels
2 to 4 times higher. The proposed standard is EPA's judgment of the most
stringent cleanup condition that may reasonably be required uniformly for
all the inactive mill sites.
The proposed standard addresses future as well as present hazards and
uses an intrinsic property of tailings that can be easily measured. We
considered other forms for the standard, such as limiting the residual
surface gamma radiation, the radon release rate, or the predicted
concentration of radon decay products in future buildings on the land.
All these would restrict the residual hazard, but they would be harder to
apply to material which has been buried, but might be uncovered later.
We expect that the rules developed to implement this standard will
relate the concentration of radium in soil to other conveniently measured
quantities. We also expect that appropriate sampling techniques will be
established to locate and identify tailings material, to determine its
concentration of radium, and to verify compliance with the standard. Any
such rules must insure that the standard is not met simply by dispersing
the material to achieve a lower concentration.
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8.2.2 Buildings
8.2.2.1 Justification for the Proposed Indoor Radon Decay Product
Concentration Standards
Exposure to even normal indoor radon decay product concentrations
carries some health risk, but we believe Congress intended that people
should not have to bear an unreasonable increase in this risk due to
tailings. Remedial action will be required when a building affected by
tailings exceeds the levels we set as the remedial action standards. When
remedial actions are finished, the level must either not be exceeded, or
else tailings must not be the cause of any remaining excess. We believe
that expressing the indoor radon decay product standard in terms of total
concentration of these products is the only workable form, as the
following discussion indicates.
Indoor radon decay product concentrations of normal buildings vary
widely. Tailings near or under a building may be identified by gamma ray
measurements, historical records, visual inspections, or specimen analysis.
However, because of the fluctuations in normal indoor radon levels, it is
impossible to tell what the concentration of radon decay products would be
without the tailings. Small elevations when tailings are present cannot be
distinguished from normal background levels. Furthermore, contaminated
buildings vary in location, design, materials, and patterns of use, all of
which affect the indoor radon decay product concentration. Therefore, it
is neither practical to determine an expected background value for a
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particular building from measurements of unaffected buildings, nor by any
other means.
For the above reasons, an action level expressed in terms of an
increment over the background radon decay product concentration could not
be implemented easily. We prefer an action level in terms of the total
indoor concentration, which is directly measurable. With a fixed
measurement method, this standard gives an unambiguous decision of
eligibility for remedial action for any building affected by tailings.
We also considered expressing the standard in terms of the quantity
or concentration of tailings near the building, or the gamma radiation
they produce. However, there is no sure way to relate these quantities to
indoor radon decay product concentrations. This is a critical deficiency,
because the radon products are the basic hazard.
A standard for total concentration of radon decay products provides
the same action level for all affected buildings, regardless of whether
normal concentrations in one affected area may tend to be higher than in
another. While normal indoor radon decay product concentrations vary with
natural radium concentrations in soil, soil porosity, and other factors,
we know of no way to take them into account in the standard. In these
circumstances, we consider the regional protection inequity minor, as long
as the action level we choose is within the normal range of levels in the
affected areas.
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We believe that the proposed remedial action level of 0.015 WL
(including background) for occupied or occupiable buildings is the most
protective level that can be justified for the PL 95-604 remedial action
program. It is about the same as that applied to homes and schools over
the last seven years in the Grand Junction remedial action program,
because the action level there was 0.01 above an "average" background
value taken as 0.007 WL. Experience in the Grand Junction program and
studies performed by EPA for homes in Florida (without basements) indicate
that remedying concentrations greater than 0.015 WL is usually practical
in view of technical and cost considerations. In some situations, a lower
action level might be justified. However, studies of normal houses with
basements in Grand Junction, New York, and New Jersey indicate that about
10 percent or more are above 0.015 WL. We have concluded that efforts to
reduce levels significantly below 0.015 WL by removing tailings would
often be unfruitful, and the funds expended wasted.
Although indoor radon decay product levels exceeding 0.015 WL can
occur without the presence of uranium mill tailings, these proposed
standards are explicitly for remedial actions at sites designated under
PL 95-604.1 PL 95-604 is clearly directed at potential health problems
due to tailings, and not to similar hazards from other causes. It is not
our intention for there to be lengthy and expensive procedures to determine
1In particular, the proposed remedial action standard should not
necessarily be taken as an appropriate design goal for indoor radon
decay product concentration in new housing.
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whether any tailings are present when the level is only slightly exceeded.
Professional judgment in the field must be relied upon in such cases for
sensible implementation of the standards. If the allowable level is still
exceeded after all apparent tailings have been removed or otherwise
prevented from affecting the interior of the building, then the standard
would not require further remedial measures.
8.2.2.2 Standards for Indoor Gamma Radiation
The proposed limit on indoor radon decay product concentration is
based on the hazard from breathing air containing these products. Tailings
also emit gamma radiation, however, which can penetrate the body from the
outside. We expect the indoor radon decay product concentration standards
generally will be met by removing of the tailings from the building, and
this will eliminate any indoor gamma radiation problem. It is only in
unusual cases that a standard for limiting gamma radiation exposure may be
needed.
It will often be possible to meet the radon decay product standards
without removing the tailings. Removal is the remedial method we wish
most to encourage, however, because of its positive and long lasting
effectiveness. To this end, we propose an action level for gamma
radiation of 0.02 mR/hr above background,1 which allows a limited degree
Indoor background levels of gamma radiation are easier to determine
and less variable than is the case for measurements of radon decay
product concentration.
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of flexibility in the methods for reducing indoor radon decay product
concentrations. On the other hand, reducing the standard much below
0.02 mR/hr would virtually eliminate flexibility in remedial methods, and
provide only a small additional health benefit to those few individuals
who might be affected. Assuming the occupants of the building to be
present 75 percent of the time, the proposed standard would allow gamma
radiation doses from the tailings of about 130 mrad per year. This is
about twice the average annual background dose from gamma rays in the
regions near the piles.
8.2.2.3 Radiation Hazards not Associated with Radium-226
The total protection provided by a standard based on radium-226
depends on the extent to which radium has been separated from other
radioactive substances during ore processing. Radium-226 concentrations
in the residual material may not be an adequate measure of the radiation
hazard in all cases.
For the reasons discussed in Sec. 7.3, we are not yet able to say in
all cases how effective cleanup standards based on radium-226 will be in
controlling U-235 decay products and thorium, and we are not in a position
to set a separate standard for them. It is our judgment, however, that
adequate protection would be provided if, after cleanup, the total risk
from all uranium and thorium isotopes and their decay products posed no
greater risk than the proposed final cleanup standards allow for
radium-226 and its decay products. The degree to which any particular
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site would need to be cleaned in order to meet this condition will have to
be determined following detailed studies of its tailings, and further
evaluation of the hazard pathways.
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References for Chapter 8
(AE 77) Atomic Energy Control Board (of Canada), April 7, 1977,
"Criteria For Radioactive Clean-up in Canada," Information
Bulletin 77-2.
(CH 79) Chappell, W.H., et al.., 1979," Human Health Effects of
Molydbenum in Drinking Water," USEPA Health Effects Research
Laboratory Report, EPA-600/1/79-006.
(EP 76) U.S. Environmental Protection Agency, 1976, "Quality Criteria
for Water," Report EPA-440/9-76-023.
(EP 78) U.S. Environmental Protection Agency, June 1978, "State of
Geological Knowledge Regarding Potential Transport of High-Level
Radioactive Waste From Deep Continental Repositories," Report
EPA/520/4-78-004.
(FB 76-78) Ford, Bacon, and Davis, Utah, Inc., "Phase II-Title 1,
Engineering Assessment of Inactive Uranium Mill Tailings"
20 contract reports for Department of Energy Contract
No. E(05-D-1658, 1976-1978.
(FR 79) Federal Register 44. p 53438-53468, September 13, 1979;
40 CFR Part 257.
(FR 79a) Federal Register 44. p 23738-23767, April 20, 1979.
(GJ 79) Grand Junction Office, February 1979, "Progress Report on the
Grand Junction Uranium Mill Tailings Remedial Action Program,"
U.S. Department of Energy Report DOE/EV-0033-
(GS 78) U.S. Geological Survey, 1978, "Geologic Disposal of High-Level
Radioactive Wastes — Earth-Science Perspectives," Circular 779.
(HE 78) Healy, J.W., and Rodgers, J.C., October 1978, "A Preliminary
Study of Radium-Contaminated Solid," Los Alamos Scientific
Laboratory Report LA-7391-MS.
(NE 78) Nelson, John D., and Shepherd, Thomas A., April 1978,
"Evaluation of Long-Term Stability of Uranium Mill Tailing
Disposal Alternatives," Civil Engineering Department, Colorado
State University prepared for Argonne National Laboratory.
(NR 79) U.S. Nuclear Regulatory Commission, April 1979, "Draft
Generic Environmental Impact Statement on Uranium Milling,"
NUREG-0511.
(PE 70) Letter by Paul J. Peterson, Acting Surgeon General to
Dr. R.L. Cleere, Executive Director, Colorado State Department
of Health, July 1970.
8-30
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9. IMPLEMENTATION
9-1 Administrative Process
Public Law 95-604 requires that EPA's standards for uranium mill
tailings from inactive processing sites be implemented by the Secretary of
the Department of Energy (DOE). The Secretary or a designee will select
and perform remedial actions for designated processing sites in accordance
with the standards, with the full participation of any State which shares
the cost. Selection and performance of the remedial actions will be with
the concurrence of the Nuclear Regulatory Commission and in consultation,
as appropriate, with affected Indian tribes and the Secretary of the
Interior. The costs of the remedial actions will be borne by the Federal
government and the States as prescribed by law.
9.1.1 Disposal Standards
The disposal standards will be implemented by showing that the
disposal method provides a reasonable expectation of satisfying the radon
emmission limits and water protection provisions of the standard for at
least 1000 years. We intend for this expectation to be founded upon
analyses of the physical properties of the disposal system and the
potential effects of natural processes over time. Computational models,
theories, and expert judgment will be major tools in deciding that a
proposed disposal system will satisfy the standard. Post-disposal
monitoring can serve only a minor role in confirming that the standards
are satisfied. It is not reasonabe to expect that any violations
-------
discovered hundreds of years from now will be remedied under the authority
of PL 95-604. The disposal standards must be satisfied in the current era
by methods that provide a reasonable expectation of continued
effectiveness over the required period.
9.1.2 Cleanup Standards
Subsequent to making a radiation survey of open lands and buildings in
areas believed to have tailings, DOE must determine whether or not tailings
are causing the standards to be exceeded. After performing necessary
remedial actions to reduce radiation levels, it will be necessary to verify
compliance with the standards. To conduct these activities, DOE, working
with NRG, will need to develop radiological survey, sampling, and measure-
ment procedures to determine necessary and practical cleanup actions, and
to certify the results of the cleanup. We have published elsewhere the
general requirements for an adequate land cleanup survey (EP 78a).
These procedures are significant elements in determining the effec-
tiveness of the standards. In view of this, we considered providing more
details of the implementation as part of our rulemaking. We chose not to
do so in order to give more flexibility to the implementers. We believe
this is warranted because of widely varying and incompletely known
conditions among and within the various processing sites. However, the
following clarification of our intentions should help to avoid unproductive
use of resources. This could result if the standards were interpreted so
strictly that demonstrating compliance would be unreasonably burdensome.
9-2
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The purpose of our standards is to protect public health and the
environment. We designed them to be adequately protective using search
and verification procedures whose cost and technical requirements are
reasonable. For example, since we intend the cleanup standards for
buildings to protect people, measurements in such locations as crawl
spaces and furnace rooms are inappropriate. Remedial action decisions
should be based on radiation levels in occupiable parts of the buildings.
The standards for cleanup of land surfaces are designed to limit exposures
of people to gamma radiation, and to radon decay products in future
buildings. In most circumstances, failure to clean a few square feet of
land contaminated by tailings would be insignificant. Similarly, in
attempting to find tailings which are below the surface on open land,
reasonableness must prevail in determining where and how deeply to search.
It would be unreasonable to require proof that all the tailings had been
found. In all applications of our proposed cleanup standards, search and
verification procedures which provide a reasonable assurance of compliance
with the standards will be adequate. We are confident that DOE and NEC,
in consultation with EPA, will adopt specific implementation procedures
which apply most of the resources to reducing radiation exposures, and
will minimize the resources needed for surveys.
9-3
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9.2 Exceptions
We believe that our proposed standards are the strictest that are
justified for general application at all the inactive uranium processing
sites covered by PL 95-604. However, providing greater protection may be
reasonable at specific sites. Therefore, we urge the implementers to
lower the residual risk as far as reasonably achievable, within the limits
set by the standards.
In the decades since tailings at inactive sites were deposited,
weather and people have created a wide range of problems needing remedi-
ation. There may be exceptional circumstances for which the standards are
unreasonably strict. If it is impossible to meet the standards, or if some
clearly undesirable health or environmental side-effects are unavoidable,
applying the standards would not be justified. For example, when tailings
are not accessible to the equipment needed for their removal, or where
workers might be endangered in trying to remove them, application of the
standards should be reconsidered. Similarly, distrubing scarce desert
vegetation and soils may not be justified where the standards are only
slightly exceeded.
We do not consider cost a reason for noncompliance unless the cost to
comply is very high or the benefit is very small. For example, it may not
make sense to spend a great deal of money to clean up an infrequently
occupied building where the standards are only slightly exceeded.
In order to allow for reasonable implementation of PL 95-604 in all
of the varied circumstances, we are proposing criteria which the
implementers may use to determine whether particular circumstances are
9-4
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exceptional. In such exceptional cases, DOE may select and perform
remedial actions which come as close to meeting the standards as is
reasonable. In the selection of such remedial actions, DOE shall ask any
property owners and occupants for their comments, the concurrence of NRC
shall be required, and DOE shall inform EPA.
9-5
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9.3 The Effects of Implementing the Standards
9.3-1 Health
The proposed standards reduce average radon emissions of the tailings
piles more than 99% for one thousand years. If the current rate of lung
cancer deaths would otherwise have persisted, then we estimate applying
the standards will avoid about 2000 premature lung cancer deaths.
Some people now living very near tailings piles could bear a risk of
premature death due to lung cancer of several chances in 100. Under the
disposal standards, people living in comparable locations during the next
1000 years will bear much lower risk from the pile, about 1 chance in
10,000.
After remedial actions are completed on buildings eligible under
PL 95-604, their occupants will be subject to radon decay product
concentrations less than 0.015 WL (including background), and gamma
radiation exposure rates lower than 0.02 mR/hr. Their estimated total
risk of fatal cancer due to residual tailings following remedial action
will average less than about 1/&. This is within a normal range of
fluctuation for risk due to indoor radon decay products alone in the
absence of tailings.
After remedial actions are carried out on eligible open land,
residual contaminated materials will have less than 5 times the radon
9-6
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release of average soils. It could also cause a gamma radiation dose of
less than 80 millirad per year to a person who spends 100 percent of the
time outdoors on the site. These levels of radon emission and gamma
radiation are within the variations that occur in undisturbed land areas.
We believe that the actual radon and gamma ray levels after cleanup will
usually be much less than the maximum possible under these standards.
radium-226, almost certainly distributed in a thin layer. Gamma radiation
from a 5 centimeter thickness of residual soil having the maximum allowable
concentration under the standard could produce about 2 chances in 1000 of
fatal cancer for a person exposed outdoors continuously over a lifetime.
Actual exposures will be much lower. The gamma radiation increment over
the affected region would be within a normal range of fluctuation among
similar regions which are unaffected by tailings.
9.3.2 Environmental
Tailings will be controlled for at least 1000 years under the proposed
standards, so dispersal by floods, erosion, or mass movement should not
occur during that period. Releases of radon gas to the air from the site
will be slightly above average, but within a normal range. High quality
ground water will be protected for a wide range of uses, including
drinking; lower quality ground water will not be degraded by the tailings.
Contaminated open land will be subjected to scraping and digging by
the cleanup operations. Generally these activities will occur immediately
adjacent to the piles, but off-site areas where tailings had been purpose-
9-7
-------
fully used will also be affected. Disposal operations may require large
quantities of clay and soil for covering the tailings (depending on the
disposal method). The environmental effects of obtaining these materials
will vary with the site. The general ecological effects of land cleanup
and restoration operations are examined in detail in an EPA report
(EP ?8b).
9.3.3 Economic
The total cost of disposing of all the tailings piles eligible under
PL 95-604 is difficult to estimate, primarily because methods will be
chosen site-specifically. We estimated the cost of covering an average
pile to meet the proposed radon emission standard as $1-6 million if the
existing site is suitable, or $6-13 million for a new location. Therefore,
the total disposal cost for all sites would be $21-273 million. Deep
burial and chemical treatments could be considerably more expensive.
Cleanup costs for open land and buildings have been estimated using
interim cleanup criteria as about $10 million (see Section 7.4). Even
allowing for increased costs under the proposed standards, tailings
disposal is still by far the largest cost component of the remedial action
program.
Although difficult to estimate, the total cost of the entire program
probably will be $200-300 million. These costs will be shared by the
Federal Government (90%) and any State government (10%) in which an
9-8
-------
inactive processing site is located. We expect the expenditures will be
spread over the seven-year authorization of the program. Most of these
expenditures will occur in the regions the tailings are located. Their
significance depends on the amount expended, the size of the local
economy, and the availability of necessary equipment and labor.
Contaminated land and buildings may be made available for use as a
result of the cleanup program. Balancing this, when tailings are
relocated, is the removal of the new disposal site from other potential
uses.
In summary, the program could result in net economic benefits of
decreased unemployment and increased business activity for the regions the
piles are located. We expect little or no perceptible national economic
impact because the total seven-year expenditures will be small compared to
the annual Federal budget (less than 0.06$ of 1978 budget), the annual
Gross National Product (less then 0.01$ of 1978 GNP), and the construction
industry (less than Q.5% of 1978 billings).
9-9
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9.4 The Proposed Standards
The proposed standards are presented in Appendix C,
9-10
-------
References for Chapter 9
(EP 78a) "Response to Comments: Guidance on Dose Limits for Persons
Exposed to Transuranium Elements in the General Environment," EPA
Technical Report 520/4-78-010.
(EP 78b) "The Ecological Impact of Land Restoration and Cleanup,"
August 1978, EPA Technical Report 520/3-78-006.
9-11
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APPENDIX A
Comments
-------
APPENDIX B
Development of Cost Estimates
-------
APPENDIX B
Development of Cost Estimates
B.1 The Average Inactive Uranium Mill Tailings Pile
B.2 Development of Unit Cost Computations 4
B.2.1 Earth Work 4
B.2.2 Caps and Liners 8
B.2.3 Stabilization 9
B.2.4 Fencing 11
B.2.5 Irrigation 12
B.2.6 Matrix Fixation 12
B.2.7 Tailings Transportation 13
B.2.8 Discount Rate 16
B.2.9 Present Worth of Future Costs 16
B.2.10 Land Costs 17
B.3 Cost Estimates For Disposal Options 18
B.3-1 Option 1 - No Radon Control 18
B.3.1.1 Option 1a - Fencing 18
B.3.1.2 Option 1b - Stabilization With No Radon Control . . 19
B.3.2 Controlling Radon Emissions with an Overburden ... 22
8.3.3 Option 2 - Existing Surface Site, Covered
to Control Radon Emissions 22
B.3.3.1 Dimensions 24
B.3.3.2 Cost Estimates 26
B.3-3.3 Use of Tables B-7 Through B-11 32
B.3.4 Option 3 - New Site, Below Grade, with Liner if
Needed 34
B.3.4.1 Requirements 34
8.3.4.2 Dimensions and Cost Estimates 36
B.4 Other Disposal Methods 44
B.4.1 Extraction and Disposal of Hazardous Materials ... 44
B.4.2 Long-Term Radon and Hydrology Control 49
References for Appendix 8 54
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FIGURE
Page
B-1 Cross-Section of the "Average" Mill Tailings Pile 3
TABLES
Page
B-1 Unit Costs 5,6
B-2 Estimated Capital Costs of Matrix Fixation 14
B-3 Annual Operating Costs for Matrix Fixation 15
B-4 Costs and Dimensions of Particulate Control 21
B-5 Thickness (meters) of Cover Required to Reduce Radon to
Control Level 23
B-6 Control Methods for Disposal Option 2 25
B-7 Costs and Dimensions for Disposal Option 2 with Control
of Radon to 100 pCi/m2/sec 27
B-8 Costs and Dimensions for Disposal Option 2 with Control
of Radon to 10 pCi/m2/sec 28
B-9 Costs and Dimensions for Disposal Option 2 with Control
of Radon to 5 pCi/m2/sec 29
B-10 Costs and Dimensions for Disposal Option 2 with Control
of Radon to 2 pCi/m2/sec 30
B-11 Costs and Dimensions for Disposal Option 2 with Control
of Radon to 0.5 pCi/m2/sec 31
B-12 Control Methods for Disposal Option 3 35
B-13 Constant Costs for Below-Grade Disposal of Uranium Mill
Tailings 37
B-14 Variable Costs and Dimensions for Disposal Option 3 with
Control of Radon to 100 pCi/m2/sec 39
B-15 Variable Costs and Dimensions for Disposal Option 3 with
Control of Radon to 10 pCi/m2/sec 40
B-16 Variable Costs and Dimensions for Disposal Option 3 with
Control of Radon to 5 pCi/m2/sec 41
B-17 Variable Costs and Dimensions for Disposal Option 3 with
Control of Radon to 2 pCi/m2/sec 42
B-18 Variable Costs and Dimensions for Disposal Option 3 with
Control of Radon to 0.5 pCi/m2/sec 43
B-19 Costs of Nitric Acid Leachate Disposal 47
B-20 Costs of Residual Tailings Disposal 50
B-21 Cost Estimates of Deep Disposal When a Nearby Open-pit
Mine is Available 52
B-22 Cost Estimates of Deep Disposal When a Nearby Underground
Mine is Available 53
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APPENDIX B
Development of Cost Estimates
B.1 The Average Inactive Uranium Mill Tailings Pile
For the purpose of developing cost estimates of the various uranium
mill tailings disposal methods, we employed an "average" inactive uranium
mill tailings pile, with dimensions based upon the average dimensions
found at the 21 inactive uranium mill tailings sites. The tailings area,
volume, and weight dimensions have been computed from the information
found in the Ford, Bacon and Davis, Utah, Inc, engineering reports on the
inactive uranium mill tailings sites (FB 76-?8).
The "average" pile has the configuration of s. truncated regular pyra-
mid with a lower base of 436m on a side including embankments. Figure 3-1
gives a cross section of the uranium mill tailings impoundment area. The
mill tailings pile covers a surface area of a little more than 19 hectares
(190,000m2, or 47 acres). The embankments contain 784,000m3
(1,026,000 yd3) of uranium mill tailings that weigh 1,325,000 short
tons, and the tailings are assumed to be 5.0m deep within the embankments.
Furthermore, it is assumed that when the uranium milling operations had
ceased at the location, the tailings pile was left flat on top but
uncovered, and there is evidence of both wind and water erosion. Tests
indicate that tailings have migrated as far as 1000m from the average
tailings pile.
B-2
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B.2 Development of Unit Cost Computations
The unit costs used for estimating the costs of the disposal options
are presented in Table B-1. They are average costs and represent the
expected monetary values that will be encountered while completing indi-
vidual tasks, or purchasing specific items necessary for the various
uranium mill tailings disposal methods considered in this report. The
unit costs are evaluated in 1978 dollars and reflect the economic
conditions of that year.
The procedures used to derive the unit costs are as follows:
a. Any costs not already evaluated in 1978 dollars, are adjusted
to reflect 1978 values using an appropriate price index (usually the U.S.
Department of Commerce Composite Construction Cost Index published in the
Survey of Current Business).
b. When only one source for the cost of an item is available,
that value is used.
c. When more than one cost estimate is available, the average
of these values is used.
B.2.1 Earth Work
The sources for computing the costs for various types of earth work
are Dodge (DO 78), Means (RA 77), and the NRC-DGEIS (NR 79).
B-4
-------
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-------
TABLE B-1
Unit Costs
Task Cost (1978 dollars)
1. Earth work
a. Below grade excavation in normal soil $1.63/m3
Below grade excavation in shale $3.10/m3
b. Dragline excavation and loading $1.53/m3
c. Excavate, load, and haul $1.13/m3
d. Spread and compact $0.38/m3
e. Haul, dump, spread, and compact $1.33/m3
2. Caps and Liners
a. Clay when available $2.07/m3
b. Clay when purchase is required $5.00/m3
c. Synthetic $4.4l/m2
d. Asphalt emulsion (1/2" thick) $1.76/m2
3- Stabilization
a. Vegatation when soil is available $0.75/m2
b. Vegatation when soil purchase is required $2.51/m2
c. Rip rap (.5m thick) $12.90/m2
d. Gravel (.5m thick) $2.57/m2
e. Chemical $0.7*1/m2
4. Fencing
a. 5-6 foot high chain link fence $29.69/m
b. Security fence (prison grade) $84.51/m
5. Irrigation
a. Equipment (excluding pumps) $1070/hectare
b. Annual operating costs $273/hectare
c. Submersible pump $1000 each
B-5
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TABLE B-1 (continued)
Unit Costs
Task Cost (1978 dollars)
6. Matrix Fixation
a. Cement with thermal evaporator
capital costs $4,750,000
annual operating costs $6,575,000
b. Cement with filter bed
capital costs $6,550,000
annual operating costs $2,140,000
c. Asphalt with thermal evaporator
capital costs $7,900,000
annual operating costs $8,515,000
d. Asphalt with filter bed
capital costs $9,700,000
annual operating costs $4,070,000
7. Tailings Transportation
a. Truck $0.10/ton-mile
b. Rail $0.08/ton-mile
c. Pipeline (7" diameter)
capital equipment and right-of-way $63,840/mile
operating costs $0.048/ton-mile
8. Discount rate (real rate of return) 7%
9. Future Costs
a. Vegetation stabilization
Annual operating cost $3,900/hectare
Irrigation equipment $400/hectare
Submersible pump $2,500 each
b. Chemical stabilization $23,800/hectare
c. 5-6 foot high chain link fence $4.27/m
d. Security fence (prison grade) $12.17/m
10. Land Costs (farmland) $781/hectare
B-6
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There are two types of below-grade excavation depending on the
consistency of the material being excavated (i.e., normal and shale).
Although classified as one category, normal below-grade excavation is not
homogeneous; it includes digging in soft soil as well as various forms of
clay. Similarily, the costs of excavating in such a variety of soil types
can vary significantly. As a result, the expected cost for normal below
grade excavation is $1.63/m3, but may actually range anywhere between
$0.56/m3 and $5.98/m3. On the other hand, when excavating shale, the
cost for below-grade excavation rises to $3.10/m3, on the average, and
may range between $2.56/m^ and $3-8l/m3.
According to Ford, Bacon and Davis, Utah, Inc. (FB 76-?8), a dragline
method of tailings excavation is required to remove the uranium mill
tailings from their present site. This method of tailings excavation is
assumed throughout this report. Estimates of dragline excavation and
loading establish the cost for removing the uranium mill tailings at
$1.53/m3.
Excavation, loading, and hauling (up to one mile) of surface soil is
expected to cost $1.13/m^, but may be as low as $0.92/m3 or as high
as $1.58/m3. Spreading and compacting materials (such as mill tailings,
top soil, clay, etc.) will average $0.38/m^, but may range between
$0.22/m3 and $0.75/m3. Finally, hauling (up to one mile), dumping,
spreading, and compacting is expected to cost $1.33/m^ and is considered
to be a single task.
B-7
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B.2.2 Caps and Liners
The sources for unit cost estimates of caps and liners are Dames and
Moore (DA 77), the NRC-DGEIS (NR 79), and Smith and Lambert (SM 78).
There are basically three types of caps and liners; clay, synthetic,
and asphaltic emulsion. The major purpose of a cap is to reduce radon
emissions from the mill tailings into the surface environment. Some
hydrologic control is also afforded by a cap because it reduces seepage
of surface water into the tailings. On the other hand, liners are used
chiefly to provide hydrologic control beneath the pile. That is, a liner
will reduce moisture seepage from the mill tailings into the ground water
or ground water infiltration into the tailings.
Assuming a nearby source of suitable clay (i.e., a clay having a
large proportion of montmorillonite) is available at no cost, a clay cap
or liner can be expected to cost $2.07/m^ to install, but may actually
range between $1.l4/m3 and $2.93/m3. If a suitable type of clay must
be purchased, an additional $2.93/m3 should be added to the cost of
installing a clay cap or liner.
Many types of synthetic materials are available which could be used
as a cap or liner for uranium mill tailings (e.g., polyster reinforced
Hypolon or Polyvinylchloride). Because these types of caps and liner
require a carefully prepared installation, they can be quite expensive.
B-8
-------
On the average, $4.4l/m2 is the expected cost of installing a synthetic
cap or liner, but the cost may range between $2.00/m2 and $11.89/m2.
The least expensive method of providing a cap or liner for uranium
mill tailings appears to be an asphaltic emulsion. Smith and Lambert
(SM 78) estimate that the cost of applying a 0.5 inch thick layer of
f}
asphaltic emulsion costs $7,1^0 an acre or $1.76/m .
B.2.3 Stabilization
All methods of stabilizing uranium mill tailings disposal sites have
a common purpose; that is, to provide wind and water erosion protection.
This reduces the quantity of uranium mill tailings that migrate from the
disposal site. Four methods of stabilization are considered in this
report: vegetation, rip rap, gravel, and chemical.
a. Vegetation used as a stabilizer consists of plant growth
which holds the surface in place. The proper installation of vegetation
requires approximately eight inches of suitable surface soil to insure
plant propagation. Besides seeding, fertilizer, lime, and soil binders
are also necessary to aid plant growth until a ground cover is
established. If it is assumed that a suitable type of top soil is
locally available, the cost of providing a cover of vegetation will cost
$0.75/m2, but may range between $0.38/m2 and $1.12/m2. If top soil
and loam must be purchased, then the cost of vegetation becomes
B-9
-------
significantly more expensive (i.e., the average cost will be $2.51/nr
and range between $1.48/m2 and $3-93/ni^). These cost estimates do
not include the cost of irrigation for those areas where adequate
precipitation to maintain vegetation is not available. The capital and
operating expenditures associated with irrigation are discussed later.
b. Rip rap consists of large stone or concrete chips (1/4 to
3/8 yd3 in size) in a layer approximately 0.5m thick as a cover on the
uranium mill tailings disposal site. Rip rap is either placed loose or
enclosed in galvanized steel mesh boxes called gabions. Rip rap has an
average installation cost of $12.90/m^. If placed loose, rip rap can
cost as little as $4.?8/m2. But if the rip rap must be enclosed in
gabions, the cost of providing a rip rap cover may be as high as
$25.79/m2.
c. Like rip rap, gravel provides wind and water erosion protec-
tion for the uranium mill tailings disposal site, and an 0.5m thick cover
of gravel is assumed to be required for adequate wind and water erosion
fy
protection. Installing a 0.5m thick gravel cover costs $2.57/m , on
average, but ranges between $2.49/m^ and $2.73/m .
d. Other types of covers, categorized here as chemical
stabilizers, include asphalt, asphaltic emulsion, road oil, and various
other chemicals. Although the chemical stabilizers appear to be the
least expensive method of stabilizing a uranium mill tailings disposal
8-10
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site (i.e., average cost of installation is $0.75/m2), the cost of
application has a wide range (between $0.05/m2 and $9.69/m2).
Furthermore, their long-term stability is untested. Some methods require
replacement in less than a year while others may last as long as twenty
years or more. For cost estimation, it is assumed that a chemical
stabilizer will need replacement very four years.
B.2.1* Fencing
Sources for unit costs of fencing are Dodge (DO 78), Means (ME 77),
the NRC-DGEIS (NR 79), and Smith and Lambert (SM 78).
Isolation of the uranium mill tailings disposal site from intrusion
can be accomplished by a fence barrier. Two types of fences are consid-
ered in this report. A 5 to 6 foot high chain link fence with or without
several strands of barbed wire on top costs an average of $29.69/m to
install, but may range between $21.33/m and $49.21/m. If more security
from intrusion is required, a 12 to 16 foot high security fence (prison
grade) will cost $84.51/m for installation, but may be as low as $73.49/m
or as high as $95.5Vm. These costs include instalation, corner posts,
and a gate. The effective life of these fences is assumed to be 100
years, if proper maintenance is performed. Annual maintenance costs for
the fences are expected to be 1$ of the original expenditure for the
fences.
B-11
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B.2.5 Irrigation
The capital and annual operating expenditures for irrigation used in
this report have been taken from the NRC-DGEIS (NR 79). All costs are
stated on a per hectare basis, except for submersible pumps. Annual
operating expenditures for running and maintaining irrigation equipment
are expected to be $273 per year per hectare. This value includes
fertilizer, power, operating labor, maintenance on the irrigation equip-
ment, and ground water analyses. Installation of the irrigation
equipment, including pumps, and miscellaneous valves and nozzles, will
cost $1,070 per hectare. It is expected that this equipment will need
replacement an average of every 20 years. In addition, one submersible
pump is required for every 20 hectares to be irrigated at a cost of
$1,000 each. Replacement of the submersible pumps can be expected every
5 years.
B.2.6 Matrix Fixation
Uranium mill tailings could be incorporated into a concrete or
asphalt mixture, thus reducing the leachability of the tailings into the
hydrologic system. A detailed discussion of the methods and require-
ments for fixing uranium mill tailings in a concrete or asphalt matrix
can be found in the NRC-DGEIS (NR 79).
B-12
-------
Detailed breakdown of the estimated capital expenditures and annual
operation costs for the various methods of matrix fixation are given in
Tables B-2 and B-3. These tables have been taken directly from the
NRC-DGEIS (NR 79), Tables 11.9 and 11.10, respectively.
From a cost standpoint, significant savings can be realized in
initial capital costs and in annual operating expenditures if a cement
matrix is used rather than an asphalt matrix. In addition, the method of
drying the tailings before incorporation into either a cement or asphalt
matrix has significant cost implications. For both concrete and asphalt
fixation, initial capital costs are somewhat less expensive for
mechanically drying the tailings (via a thermal evaporator) than for
drying the tailings with a "dewatering filter bed" (i.e., a sand filter).
However, significant savings in annual operating expenditures can be
gained by using the "dewatering filter bed" rather than the thermal
evaporator. That is, annual operating costs are at least a factor of two
less than those for a thermal evaporator for both cement and aslphalt
matrix fixation.
B.2.7 Tailings Transportation
Three methods of hauling uranium mill tilings were considered:
truck, rail, and pipeline for slurry. According to Ford, Bacon and
Davis, Utah, Inc. (FB 76-78), contract haulers can transport mill
tailings at a cost of $0.10/ton-mile. For longer distances (e.g.,
B-13
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TABLE B-2
Estimated Capital Costs of Matrix Fixation
.(a)
(thousands of 1978 dollars)
Equipment
Sand washing and drying
Lime neutralization
Thermal Evaporator
Cement Asphalt
230 230
670 670
Filter Bed
Cement Asphalt
230 230
670 670
Slimes filtration (vacuum disc
filter)
1150
1150
Tailings dewatering bed
Evaporators
Evaporation pond
Asphalt fixation
Cement fixation
TOTAL
1470
1210
4750
1470
4400
7900
2120
2300
1210
6550
2120
2300
4400
9700
(a)NRC-DGEIS (NR 79), Table 11.9.
B-14
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TABLE B-3
Annual Operating Costs for Matrix Fixation
.(a)
(thousands of
1978 dollars)
Thermal Evaporator
Costs
Salaries
Maintenance
Power
Fuel
Asphalt
Cement
Total (annual)
Cement
170
110
75
4,250
1,970
6,575
Asphalt
170
170
75
4,740
3,360
8,515
Filter
Cement
85
50
35
1,970
2,140
Bed
Asphalt
85
100
35
490
3,360
4,070
(a)NRC-DGEIS (NR 79), Table 11.10.
B-15
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50 miles or more) transporting uranium mill tailings by rail, at
$0.08/ton-mile, can offer some cost advantages over truck
transportation. However, unless the tailings pile is located at a rail
head, the tailings will have to be hauled to the rail line by truck.
Uranium mill tailings transportation by pipeline offers greatly
reduced operating expenditures as compared to either truck or rail, but
requires heavy initial capital and right-of-way costs. According to
Dames and Moore (DA 77), a 7" diameter pipeline costs $63,840/mile to
construct and to reserve the right-of-way. Transporting mill tailings
via a 7" diameter pipeline is estimated to cost $0.048/ton-mile.
B.2.8 Discount Rate
The discount rate is assumed to be 7%. This is the estimated
average real rate of return considering all elements of society (NR 76).
The real rate of return is independent of inflation (i.e., it is the
current rate of return minus the inflation rate). The discount rate is
used for computing the present discounted value of future costs (e.g., to
maintain and replace fences in the future).
B.2.9 Present Worth of Future Costs
Several control methods may require perpetual care or periodic
replacement in order to maintain the intended level of effectiveness.
B-16
-------
For example, chemical stabilization is assumed to require replacement
every four years. Fences are assumed to require annual maintenance, and
replacement every 100 years. Finally, natural precipitation may need to
be supplemented with an irrigation system to maintain a proper vegetation
cover for surface stabilization. The irrigation system is assumed to
require annual maintenance, and periodic replacement.
The present worth of all future costs are included in the cost
breakdown shown in the tables where appropriate. The formula used for
present worth calculations is:
PW =
where: PW = present worth,
C = replacement cost of the item considered, or
its periodic maintenance cost,
n = the useful life of the item, or the
periodic maintenance period,
and i = the annual discount rate.
This formula assumes maintenance and replacement continues indefinitely.
The annual discount rate used in all calculations is 1%.
B.2.10 Land Costs
Smith and Lambert (SM 78) estimate that farmland costs $781 per
hectare, on average, and may range between $160 and $5,189 per hectare.
B-17
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B.3 Cost Estimates For Disposal Options
Using the estimated unit costs (from Table B-1) and assuming the
dimensions of the average inactive uranium mill tailings pile, we have
estimated costs for the tasks that are necessary to complete various
disposal options. When considered as various combinations of the tasks,
the estimated costs offer numerous control options. In actual practice,
the choice of a specific disposal option and actual control cost will
depend on such site-specific parameters as the radon emanation rate,
size, and condition of the specific mill tailings pile.
B.3.1 Option 1 - No Radon Control
This option may be implemented by either constructing a fence around
the existing disposal site (thereby restricting access) or stabilizing
the existing mill tailings pile to reduce future wind and water erosion.
B.3.1.1 Option 1a - Fencing
In this disposal option, the uranium mill tailings pile is left at
its existing surface location and-a fence is~erected around the site. No
control of radon-222 releases, particulate releases, or ground water
impacts is provided, although fencing provides some control of direct
gamma radiation by preventing people from living near the tailings pile.
It is assumed that wind erosion can cause particulates to migrate as far
as 1000m from the pile. Therefore, it is assumed that a 1000m
exclusionary zone is required on all sides of the tailings pile.
B-18
-------
The cost of constructing a fence can be expected to range between
$290,000 for a 5 to 6 foot high chain link fence and $820,000 for a
security fence of prison grade. The present worth of annual maintenance
and replacement every 100 years is estimated to be $40,000 for a chain
link fence and $120,000 for a security fence.
In either case, the fence encloses 593.4 hectares of land. The
tailings pile is assumed to be on a 49-hectare site that is already
publically owned. It is assumed that the remainder (i.e., 593-4 -49 =
544.4 hectares) must be purchased at a cost of $430,000. The 49 hectares,
already under public ownership, is imposing a cost to society since it is
not available for alternative uses. The best alternative use is assumed
to be agricultural. That is, the market value (i.e., the opportunity
cost) of the land is estimated to be $40,000. In total, the cost for the
"no control" option is $790,000, if a 5 to 6 foot high chain link fence
is used, and $2,410,000, if a security fence is employed.
B.3.1.2 Option 1b - Stabilization With No Radon Control
The mill tailings pile is left in place in this disposal option but
is stabilized to prevent wind and water erosion. Several of the existing
inactive tailings piles have already been stabilized with about six inches
of soil cover, vegetation, gravel, or rip-rap. The equivalent of 0.5m of
rip-rap cover is required to ensure longevity. A 15cm to 0.5m dike cover
would meet short-term requirements, but would be subject to both wind and
water erosion and thus subsequent degradation. Rip-rap cover has been
utilized at one pile and experience with stabilization of large tailings
B-19
-------
piles is quite limited. This level of control might be accomplished
through the use of chemical sprays, which provide either a surface crust
or bind the surface tailings into a crust. However, experience with such
methods has indicated that the resulting crusts are not resistant to
environmental degradation (e.g., Tuba City and Salt Lake City (FB 76).
The degradation results from intrusion by man and animals, ultraviolet
radiation, and various climatological effects. Chemical sprays and
binders appear to require a protective layer of dirt or rip-rap to assure
even a relatively short lifetime of 10 years. Thus, they have a limited
applicability for this level of control.
The sides of the tailings pile must be shaped to a slope ratio of
8:1 to minimize future erosion and a 20m exclusionary zone should be
provided around the pile. Besides the two types of fences (i.e., a 5 to
6 foot high chain link fence and a security fence), several stabilization
methods are considered here. Vegetation could be employed, but may
require the purchase of a suitable type of top soil or may need an
irrigation system. Potentially, rip-rap and gravel could provide
long-term wind and water erosion protection. Finally, chemical
stabilizers provide erosion protection but are expected to need
replacement every 4 years.
Table B-4 presents the cost and dimension estimates for the
alternative methods that will control particulates at the model uranium
mill tailings pile.
B-20
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TABLE B-4
Costs and Dimensions of Particulate Control
Volume of earth work (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)
135000
247000
2140
287000
Earth work
Stabilization
Meg: with no need to
purchase soil
with purchase of soil
Irrigation
(labor & equip.)
Rip rap
Gravel
Chemical
Fencing
5'-6' high chain link
Security (prison grade)
Future Costs
Irrigation
(labor & equip.)
Chemical stabilization
5'-6' chain link fence
Security fence
Value of Land
-Costs (in $1000 of 1978 dollars).
200
180
620
40
3180
630
180
60
180
110
590
10
30
20
B-21
-------
At a minimum, the total cost of providing wind and water erosion
protection for the model mill tailings pile will be $500,000. This
includes enough earthwork to change the embankment slopes from 2:1 to
8:1, stabilization by vegetation that requires neither soil purchase or
irrigation, and a 5 to 6 foot high chain link fence. On the other hand,
the level of control could cost as much as $3,600,000, if the model pile
must be stabilized by rip-rap and isolated by a security fence.
B.3.2 Controlling Radon Emissions with an Overburden
As noted in the NRC-DGEIS (NR 79), radon emanation can be attenuated
by an appropriate thickness of overburden. The overburden may be a layer
of soil or a combination of soil and a cap (i.e., a cap consisting of
asphalt, clay, or synthetic material). For Option 2 (Existing Surface
Site, Covered to Control Radon) and Option 3 (New Site, Below Grade, With
Liner if Needed), seven types of overburden are considered for dimension
and cost estimation. The required thickness of overburden needed to
provide the five selected radon attenuation levels for each type of
overburden are presented in Table B-5.
B.3.3. Option 2 - Existing Surface Site,
Covered to Control Radon Emissions
This disposal option consits of covering the tailings pile at the
existing surface site for control of radon-222 releases. In addition,
this control option reduces wind and water erosion of the mill tailings,
attenuates gamma radiation, and provides some control of ground water
contamination. Basically, this option requires three steps to complete:
B-22
-------
TABLE B-5
Thickness (meters) of Cover Required to Reduce Radon to Control Level
2
Radon Control Level (pCi/m /sec)
100 10 5 2 0.5
Soil(a) 1.1 2.9 3-1* 4.1 5.1
Soil + 0.6 m Clay(b) o.3 0.9 1.4 2.1 3-2
Soil + 1.0 m Clay(c) o.3 0.7 0.8 1.0 1.9
Soil + Asphalt(d) — — — — 0.5
Soil + Synthetic(d) — — — — 0.5
with average radon attenuating properties.
includes both clay and soil. If thickness is 0.6m or less
then includes clay only.
(^Thickness includes both clay and soil. If thickness is 1.0m or less
then includes clay only.
(d'Asphalt and synthetic caps are assumed to reduce radon to at least
1.0 pCi/m2 sec. Thickness only includes soil. The dashes (—)
mean no soil is required.
Source: NRC-DGEIS, Table K-6.1, p.K-27. (Ref. NR 79)
B-23
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covering the mill tailings, stabilizing the pile against wind and water
erosion, and fencing the disposal area to prevent intrusion. Although
only three steps are required, there are several ways of accomplishing
each of the steps. These steps and their alternative methods are given
in Table B-6. This leads to numerous possible combinations of methods to
implement this disposal option.
B.3.3.1 Dimensions
All dimensions (which serve as the bases of the cost estimates) are
derived assuming that the existing uranium mill tailings piles and the
resultant disposal mounds are in the shape of truncated regular pyramids.
By assumption, the sides of the final disposal mound have a slope ratio
-------
TABLE B-6
Control Methods for Disposal Option 2
(Existing Surface Site, Covered to Control Radon)
1. Cover
a. Soil (normal radon attenuation properties).
b. Soil + 0.6m clay (no clay purchase required).
c. Soil + 0.6m clay (clay purchase required).
d. Soil + 1.0m clay (no clay purchase required).
e. Soil + 1.0m clay (clay purchase required).
f. Soil + asphalt.
g. Soil + synthetic.
2. Stabilization
a. Vegetation (no soil or loam purchase required),
b. Vegetation (soil or loam purchase required)
c. Irrigation required (a or b)
d. Irrigation not required (a or b)
e. Rip rap
f. Gravel
g. Chemical
3. Fence
a. 5'-6' high chain link fence
b. Security fence (prison grade)
B-25
-------
of 8:1 in order to resist future wind and water erosion. Also, an
exclusionary zone of 20m from the base of the final disposal mound is
assumed. Finally, the dimensions and conditions of the average inactive
uranium mill tailings pile are those described in Section B.1.
B.3.3.2 Cost Estimates
Cost estimates based on the dimensions of the average inactive
uranium mill tailings pile are presented, for each of five selected radon
attenuation levels, in Tables B-7 through B-11. Cost estimates for
various tasks necessary to implement Option 2 are found in these tables.
Notice that the total cost of implementing Option 2 will vary with such
things as the desired radon attenuation level, the selected type of
overburden, the method of stabilization, and the fencing.
Several points concerning the derivation of the cost estimates need
some explanation:
1. The volume of earth work, specific to a type of cover, does not
include the volume of the cap. That is, in the case of clay caps, the
volume of the clay cap is not included as part of the volume of the earth
work.
2. Earth work includes excavating, loading, hauling (up to one
mile), spreading, and compacting surface soil.
B-26
-------
TABLE B-7
Costs and Dimensions for Disposal
2
Option 2 with Control of Radon to 100 pCi/m /sec
Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)
Soil
1.1
415000
264000
2210
306000
t-.s (in !kinnn
Soil +
.6m Clay
.3
209000
251000
2160
292000
nf 1Q7fl Hnll;
Soil + Soil +
1m Clay Other
.3
209000
251000
2160
292000
Earth work 630 240 240
Cap
Clay
with clay available - 110 110
with clay purchase - 260 260
Other
asphalt -
synthetic -
Stabilization
Veg: with no need to
purchase soil 200 190 190
with purchase of soil 660 630 6§0
Irrigation
(labor & equip.) 40 40 40
Rip rap 3^10 3240 3240
Gravel 680 650 650
Chemical 200 190 190
Fencing
5'-6' high chain link 70 60 60
Security (prison grade) 190 180 180
Future Costs
Irrigation
(labor & equip.) 120 110 110
Chemical stabilization 630 600 600
5'-6' chain link fence 10 10 10
Security fence 30 30 30
Value of land 20 20 20
B-27
-------
TABLE B-8
Costs and Dimensions for Disposal
2
Option 2 with Control of Radon to 10 pCi/m /sec
Depth of cover (m)
Volume of cover (m3)
Aera of cover (m2)
Length of fence (m)
Area within fence (m2)
Pn
Soil
2.9
917000
295000
2330
339000
st-.s fin
-------
TABLE B-9
Costs and Dimensions for Disposal
Option 2 with Control of
2
Radon to 5 pCi/m /sec
Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)
Soil
3.4
1066000
304000
2360
349000
Soil +
.6m Clay
1.4
495000
269000
2230
312000
Soil + Soil +
1m Clay Other
.8
337000
260000
2200
301000
rVist. fin *10nn nf 1Q78 Hnnarsl
Earth Work 1610
Cap
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
Stabilization
Veg: with no need to
purchase soil 230
with purchase of soil 760
Irrigation
(labor 4 equip.) 40
Rip rap 3920
Gravel 780
Chemical 220
Fencing
5'-6' high chain link 70
Security (prison grade) 200
Future Costs
Irrigation
(labor & equip.) 140
Chemical stablization 720
5'-6' chain link fence 10
Security fence 30
Value of Land 30
590
210
520
200
680
40
3480
690
200
70
190
120
640
10
30
20
300
290
690
190
650
40
3350
670
190
70
190
120
620
10
30
20
B-29
-------
TABLE B-10
Costs and Dimensions for Disposal
2
Option 2 with Control of Radon to 2 pCi/m /sec
Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)
Earth Work
Cap
Clay
with clay available
with clay purchase
Soil
4.1
1283000
317000
2410
362000
1940
-
Soil +
.6m Clay
2.1
687000
281000
2280
324000
innn of 107?
880
210
520
Soil + Soil +
1m Clay Other
1.0
389000
263000
2210
305000
}/•?(•> 1 1 *D ¥*! f ]
330
360
870
Other
asphalt
synthetic
Stabilization
Veg: with no need to
purchase soil 240
with purchase of soil 790
Irrigation
(labor & equip.) 40
Rip rap 4080
Gravel 810
Chemical 230
Fencing
5'-6' high chain link 70
Security (prison grade) 200
Future Costs
Irrigation
(labor & equip.) 140
Chemical stabilization 750
5'-6' chain link fence 10
Security fence 30
Value of Land 30
210
710
40
3630
720
210
70
190
130
670
10
30
20
200
660
40
3390
680
190
70
190
120
630
10
30
20
B-30
-------
TABLE B-11
Costs and Dimensions for Disposal
2
Option 2 with Control of Radon to 0.5 pCi/m /sec
Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)
Soil
5.1
1607000
335000
2470
381000
-(Vishs Mn !fc1
Soil +
.6m Clay
3-2
1006000
300000
2350
3^5000
000 of 1Q7ft rir
Soil +
1m Clay
1.9
631000
278000
2270
321000
Soil +
Other
.5
260000
255000
2180
296000
Earth work
Cap
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
Stabilization
Veg: with no need to
purchase soil
with purchase of soil
Irrigation
(labor & equip.)
Rip rap
Gravel
Chemical
Fencing
5'-6' high chain link
Security (prison grade)
Future Costs
Irrigation
(labor & equip.)
Chemical stabilization
5'-6'chain link fence
Security fence
Value of Land
2430 1360 690
390
250
840
50
4320
860
250
70
210
150
800
10
30
30
210
520
360
870
230
750
40
3880
770
220
70
200
130
720
10
30
30
210
700
40
3590
710
200
70
190
120
660
10
30
30
300
760
190
640
40
3290
650
190
60
180
110
610
10
30
20
B-31
-------
3« Caps are assumed to cover both the tailings and the crest of the
impoundment dikes.
4. Asphalt and synthetic caps are expected to reduce radon releases
to 1.0 pCi/m^/sec without additional soil cover. As a result, cost
estimates for covers involving asphalt or synthetic caps have been
computed only for radon control levels of 1.0 pCi/m^/sec and below.
5. Several control methods in Table B-6 require periodic mainten-
ance and replacement of equipment (e.g., irrigation equipment, chemical
stabilizers, and fences). The discounted present value of these future
costs have been computed in each case.
6. After completion of the control measures, it is expected that the
use of the land within the fences will be restricted. Therefore,
alternative uses, such as agricultural, will be permanently denied. This
opportunity cost needs to be considered in the decision-making process
along with the other costs. For this purpose, the restricted land is
assumed to have agricultural uses, and the opportunity cost is equal to
the market value of the property.
B.3.3.3 Use of Tables B-7 Through B-11
Since Tables B-7 through B-11 present only the costs of accomplishing
particular tasks that may be employed in a control option, it is important
B-32
-------
that the reader understand the proper use of these tables for deriving the
total cost for a desired control option.
After selecting the desired radon attenuation level and type of
overburden (i.e., reading down one column of the selected table) one can
calculate a total cost for the selected control option.^ The total
cost is then equal to the sum of the cost of the required overburden
(i.e., earth work plus cap costs), the cost of the specific method of
stabilization (plus the cost of irrigation if required), the cost of the
desired fence, the necessary future costs, and the opportunity cost of
the restricted land (i.e., the market value of the land). For example,
^
the total cost of attenuating to a radon flux equal 5 pCi/m /sec (refer
to Table B-9) is $1,220,000, if soil plus a 1.0m clay cap is used as an
overburden (assuming a suitable clay is locally available at no cost). It
is assumed the site is stabilized with vegetation requiring both the
purchase of top soil and irrigation equipment, and that a 5 to 6 foot
high chain link fence is required.
''The column labeled "Soil + Other" in Tables B-7 through B-11 actually
represents two separate types of overburden, the combinations of soil,
and asphalt or synthetic caps. In either case, only the cost of the
asphalt or synthetic caps differ.
B-33
-------
B.3-4 Option 3 - New Site, Below Grade, With Liner if Needed
The objective of Option 3 is not only to reduce radon emanation and
gamma radiation, but also to provide greater hydrologic control than
would be afforded by Option 2.
B.3.4.1 Requirements
In addition to the three steps necessary to implement Option 2, this
option requires excavating a special pit, installing a liner (if neces-
sary), and transporting the tailings to the pit site. The need for a
liner depends on characteristics of the subsoil at the new site. If the
subsoil is relatively impervious to moisture seepage (e.g., clay with a
high montmorillonite content or impervious shale), then a special liner
may not be required. Also, selecting a new site for the pit, which is
above the water table, may obviate the need for a liner. For this option,
transporting the tailings includes excavating the tailings from their
present site, hauling them to the new site, and depositing the mill
tailings in the pit.
Like Option 2, there are several ways of accomplishing each step of
this option. Table B-12 presents each step and their alternative
methods. Considering each possible combination presented in Table B-12
leads to numerous methods of implementing this disposal option.
-------
TABLE B-12
Control Methods for Disposal Option 3
(New Site, Below Grade, with Liner if Needed)
1. Tailings Transportation
a. Truck
b. Truck and rail
c. Pipeline
2. Below Grade Excavation
a. Normal
b. Shale (ripping necessary)
3- Liner
a. Clay (with clay available)
b. Clay (clay purchase required)
c. Asphalt
d. Synthetic
e. None
4. Cover
a. Soil (normal radon attenuation properties)
b. Soil + 0.6m clay (with clay available)
c. Soil + 0.6m clay (clay purchase required)
d. Soil + 1.0m clay (with clay available)
e. Soil + 1.0m clay (clay purchase required)
f. Soil + asphalt
g. Soil + synthetic
5. Stabilization
a. Vegetation (no soil or loam purchase required)
b. Vegetation (soil or loam purchase required)
c. Irrigation required (a or b)
d. Irrigation not required (a or b)
e Rip rap
f. Gravel
g. Chemical
6. Fence
a. 5'-6' high chain link fence
b. Security fence (prision grade)
B-35
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6.3-4.2 Dimensions and Cost Estimates
For each of five selected radon attentuation levels, dimensions and
costs were calculated for the various control methods for implementing
Option 3 (Table B-12). The distance to the new disposal site and the
geometric configuration of the pit are assumed constant in this analysis.
Several of the dimensions (and, therefore, the costs) also remain constant
regardless of the depth and type of overburden placed over the mill
tailings, while other dimensions (and costs) vary. These constant costs
are given in Table B-13-
As previously noted, there are 784,246m3 of uranium mill tailings
(weighing 1,325,376 short tons) to be excavated by dragline and hauled to
the pit site. The area to be stabilized is 176,400m2 (i.e., the pit,
regardless of depth, is assumed to be square and 420m on a side).
Similarly, 1,840m of fencing will be required to enclose 211,600m2 of
land (including both the pit and the exclusionary zone which is 20m on
each side). The excavated pit is assumed to be in the shape of a
truncated inverted regular..pyramid (i.e., with its base on top), whose
sides are required to have a slope ratio of 3:1.
The pit site is assumed to be located 10 miles from the inactive
mill tailings site. Rail heads are assumed to be situated one mile from
both the inactive tailings site and the pit site. It is assumed that the
land for the pit and its exclusion zone will be purchased at the market
B-36
-------
TABLE B-13
Constant Costs for Below-Grade Disposal of Uranium Mill Tailings
$1000 1978 dollars
Excavate, load, spread, and compact tailings 1500
Tailings Transportation
Truck 1300
Truck and rail 1100
Pipline 1280
Stabilization
Veg: with no soil purchase 130
with soil purchase 440
Irrigation
(labor and equip.) 30
Rip rap 2280
Gravel 450
Chemical 130
Fencing
5'-6' high chain link 50
Security (prison grade) 160
Land Cost 20
Future costs
Irrigation (labor and equip.) 100
Chemical stabilization 500
5'-6' high chain link fence 10
Security fence 20
B-37
-------
value of farmland. For this disposal option "earthwork" means below-grade
excavation, hauling (up to one mile), dumping, spreading, and compacting
subsoil, and disposing of any excavated subsoil not used in the cover.
The costs that vary by radon control level are given in Tables B-14
through B-18 for each selected level.
B-38
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TABLE B-14
Variable Costs and Dimensions for Disposal
p
Option 3 with Control of Radon to 100 pCl/m /sec
Depth of cover
(m)
Soil
1.1
Soil +
.6m Clay
.3
Soil +
1m Clay
.3
Soil +
Other
—
Vol. of pit
with clay liner (m3) 1145000 1014000 1014000
no clay liner (m3) 975000 837000 837000
Vol. of clay liner (m3) 170000 177000 177000
Area for other liner (m2) 172000 176000 176000
Vol. of clay cap (m3) - 53000 53000
Area for other cap (m2) -
Earth work
No clay liner
normal digging 2890
shale 4320
Clay liner
normal digging 3390
shale 5100
Liner
Clay
with clay available 350
with clay purchase 850
Other
asphalt 300
synthetic 760
Cap
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
-Costs (in $1000 of 1978 dollars).
2480
3710
3000
4490
370
890
310
780
110
260
2480
3710
3000
4490
370
890
310
780
110
260
B-39
-------
TABLE B-15
Variable Costs and Dimensions for Disposal
2
Option 3 with Control of Radon to 10 pCi/m /sec
Depth of cover (m)
Soil
2.9
Soil +
.6m Clay
.9
Soil +
1m Clay
.7
Soil +
Other
.
Vol. fo pit
with clay liner (m3) 1436000 1111000 1078000
no clay liner (m3) 1275000 941000 906000
Vol. of clay liner (m3) 162000 170000 172000
Area for other Iiner(m2) 163000 173000 174000
Vol. of clay cap (zn3) - 104000 122000
Area for other cap (m2) -
-Costs (in $1000 of 1978 dollars)-
Earth work
No clay liner
normal digging 3770 2790 2680
shale 5650 4170 4020
Clay liner
normal digging 4250 3290 3190
shale 6360 4920 4780
Liner
Clay
with clay available 330 350 360
with clay purchase 810 850 860
Other
asphalt 290 300 310
synthetic 720 770 770
Cap
Clay
with clay available - 220 250
with clay purchase - 520 610
Other
asphalt -
synthetic -
B-40
-------
TABLE B-16
Variable Costs and Dimensions for Disposal
2
Option 3 with Control of Radon to 5 pCi/m /sec
Depth of cover
(m)
Soil
3.4
Soil +
.6m Clay
1.4
Soil +
1m Clay
.8
Soil +
Other
.
Vol. of pit
with clay liner (m3)
with no liner (m3)
Vol. of clay liner (m3)
Area for other liner (m2)
Vol. of clay cap (m3)
Area for other cap
1514000
1355000
158000
161000
1195000
1026000
168000
171000
103000
1095000
924000
172000
174000
140000
Earth work
No clay liner
normal digging 4010
shale 6000
Clay liner
normal digging 4480
shale 6710
Liner
Clay
with clay available 330
with clay purchase 790
Other
asphalt 280
synthetic 710
Cap
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
-Costs (in $1000 of 1978 dollars)-
3040
4550
3540
5290
350
840
300
750
210
510
2730
4090
3240
4850
360
860
310
770
290
700
B-41
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TABLE B-17
Variable^ Costs and Dimensions for Disposal
2
Option 3 with Control of Radon to 2 pCi/m /sec
Depth of cover
(m)
Soil
4.1
Soil +
.6m Clay
2.1
Soil +
1m Clay
1.0
Soil +
Other
.
Vol. of pit
with clay liner (m3)
no clay liner (m3)
Vol. of clay liner (m3)
Area for other liner (m2)
Vol. of clay cap (m3)
Area for other cap
1621000
1468000
155000
158000
1308000
1144000
165000
167000
100000
1128000
958000
170000
173000
174000
Earth work
No clay liner
normal digging 4340
shale 6490
Clay liner
normal digging 4800
shale 7180
Liner
Clay
with clay available 320
with clay purchase ~ 780
Other
asphalt 280
synthetic 700
Cap
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
-Costs (in $1000 of 1978 dollars)-
3390
5070
3870
5800
340
820
290
740
210
500
2840
4240
3340
5000
350
850
300
760
360
870
B-42
-------
TABLE B-18
Variable Costs and Dimensions for Disposal
2
Option 3 with Control of Radon to 0.5 pCi/m /sec
Depth of cover (m)
Vol. of pit
with clay liner (m3)
no clay liner (m3)
Vol. of clay liner (m3)
Area for other liner (m^)
Vol. of clay cap (m3)
Area of other cap (m2)
Earth work
No clay liner
normal digging
shale
Clay liner
normal digging
shale
Liner
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
Cap
Clay
with clay available
with clay purchase
Soil
5.1
1771000
1620000
151000
153000
_
-
cjf^ fin 4*1000
•3 UO \J_il «p I \J\J\J
4800
7180
5240
7850
310
760
270
670
-
-
Soil +
.6m Clay
3.2
1482000
1323000
159000
162000
97000
-
nf 1Q7fl
OI I y 1 o
3920
5860
4390
6570
330
760
290
710
200
490
Soil +
1m Clay
1.9
1277000
1110000
166000
168000
169000
-
«4*^ll«*AMl
3290
4920
3780
5660
340
830
300
740
350
850
Soil +
Other
.5
1045000
872000
173000
175000
.
174000
2580
3860
3090
4630
360
870
310
780
-
-
Other
asphalt
synthetic
310
770
B-43
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B.4 Other Disposal Methods
There are several high cost alternatives to the disposal methods
previosly considered. These methods are discussed in the NRC-DGEIS
(NR 79). Two of these methods are considered here: burial in a strip-
mine or underground mine, and nitric acid leching for the removal of
hazardous materials. Potentially, these alternatives offer considerable
radon attenuation (below 0.5 pCi/m^/sec), but the long-term
environmental impact of these methods has not been tested.
B.4.1 Extraction and Disposal of Hazardous Materials
Technology has not been developed for extracting radium or
nonradiological elements from the tailings, because there has been no need
for this method for disposing of tailings.
A nitric acid leaching plant could be set up to remove the radium and
thorium in the tailings. Tailings from this process would still require
some treatment although the radioactivity level would be considerably
lower. Some of the nonradiologically hazardous elements would remain.
Seepage from the new pile would contain nitrates instead of the sulfates
found in a conventional mill tailings. Nitrates are quite mobile if the
seepage reaches ground water. The cost of chemical treatment of tailings
is as yet undetermined, but could be expected to be as expensive as the
original milling process, excluding ore grinding. Since this technique is
expected to be only about 90% effective, some action would still be
-------
required to isolate the tailings from the biosphere and to dispose of the
extracted material in a licensed waste burial site.
Uranium mill tailings disposal by a nitric acid leaching process
requires the construction and operation of a nitric acid leaching mill,
the disposal of the concentrated nitric acid leachate, and the disposal of
the residual tailings. The construction and operation of a nitric acid
leaching mill is quite expensive. The NRC-DGEIS (NR 79) estimates that a
model nitric acid leaching mill costs $35 million to construct and an
additional $37.7 million to equip (1978 dollars), while operating costs
are expected to run $12.50 per ton of processed uranium mill tailings.
Assuming the model inactive mill pile contains 1,325,000 short tons
of tailings and a model nitric acid leaching mill can process 1,984 short
tons (1800 metric tons) of mill tailings and produce 55 short tons (50
metric tons) of nitric acid leachate per day, then 668 days of operation
are required to process the mill tailings. In addition, approximately
37,000 short tons of nitric acid leachate will be generated. Consequently,
the total operating cost for a model nitric acid leaching mill at the model
inactive mill tailings pile is expected to run $16.6 million. Some of the
construction materials used in a model nitric acid leaching mill might be
employed at more than one inactive mill tailings site, or might have some
scrap value. These possibilities are not analyzed here, due to the
uncertainties of apportioning construction costs and determining future
scrap values. We therefore assume that each inactive mill tailings site
B-45
-------
requires the construction of a new nitric acid leaching mill at a cost of
$35 million. On the other hand, we assume that the nitric acid leaching
equipment can be used at more than one inactive mill tailings site. As a
result, cost of the nitric acid leaching equipment is equal to its
depreciated value. Assuming two years of use at the model inactive mill
tailings site, a fifteen year life expectancy for the nitric acid leaching
equipment, and straight-line depreciation, the expected cost of the nitric
acid leaching equipment is $5 million at each model inactive mill tailings
site. An additional $5 million is added to cover the costs of transport-
ation between different mill tailings sites, set-up and take-down costs,
and extra wear and tear on the equipment, as well as other contingencies.
Therefore, we expect the total nitric acid leaching equipment costs to be
$10 million. In total, we expect nitric acid leaching to cost $61.6
million (1978 dollars) to construct, equip, and operate the model inactive
mill tailings site.
When combined in an asphalt or cement matrix, the nitric acid
leachate matrix has a volume of 17,08lm3 and requires a cover 10m thick
for proper disposal. The disposal of the nitric acid leachate would
require a pit 13.^Sm deep and covering an area of .5 hectares (100m by
50m). The possible costs of disposing of the nitric acid leachate are
presented in Table B-19.
The NRC-DGEIS (NR 79) estimates that the concentration of radium
remaining in the residual tailings after nitric acid leaching is at least
an order of magnitude greater than background levels. If soil with
average radon attenuation properties is available in the area, a 3-8m
B-46
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TABLE B-19
Costs of Nitric Acid Leachate Disposal
($1000 of 1978 dollars)
Task Cost
Earth work
Normal digging 200
Shale 300
Fixation
Asphalt 560
Cement 380
Stabilization
Vegetation
No need to purchase soil 4
With soil purchase 30
Irrigation 2
Rip rap 60
Gravel 10
Chemical 4
Fencing3
5'-6' high chain link fence 10
Security (prison grade) fence 40
Future costs
Irrigation 10
Chemical stabilization 30
5'-6' high chain link fence 2
Security (prison grade) fence 10
Value of land 1
B-47
-------
thick cover will provide attenuation to .1 pCi/m^/sec. Assuming the
nitric acid leaching process does not significantly alter the quantity of
residual tailings and the assumptions that were employed for Option 3
(Section B.3.4 — New Site, Below Grade, with Liner if Needed), then the
disposal costs for the residual tailings can be computed. The costs of
disposing of the residual tailings are presented in Table B-20.
In summary, nitric acid leaching of the tailings for the model
inactive mill site will cost $61.6 million. Under the best conditions,
disposal of the nitric acid leachate can be expected to cost an additional
$600,000 (normal soil excavation, stabilization with vegetation (no
irrigation required), and isolation with a 5'-6' high chain link fence).
Under the worst conditions, the cost of disposing of the nitric acid
leachate will run $970,000 (shale excavation, rip rap stabilization and
security fence isolation). Disposal costs for the residual tailings
will, at best, be $7,010,000, if no liner is required, excavation is in
normal soil, tailings are transported by truck and rail, vegetation
requiring no irrigation is used to stabilize the disposal site, and the
disposal site is isolated with a 5'-6' high chain link fence. On the
other hand, the costs of disposing the residual tailings could be as high
as $13,060,000, if a clay liner is used (and the clay must be purchased),
pit excavation is in shale, only truck transportation is available for
the tailings, and the disposal site is stabilized by rip rap and isolated
by a security fence. As a result, the cost of uranium mill tailings
disposal at the model inactive mill site, via a nitric acid leaching
process can be expected to range between $96.9 and $103-3 million.
B-U8
-------
B.4.2 Long-Term Radon and Hydrology Control
It is not reasonable to expect that complete isolation of the
uranium mill tailings can be accomplished at the existing sites. The
concept of complete long-term isolation (of both radon and ground water)
essentially requires special site selection and emplacement techniques.
The NEC DGEIS (NR 79) describes two such methods that will meet this
criteria: deep disposal in an open-pit mine and deep disposal in an
underground mine.
In the case of an open-pit mine, the mill tailings may be loosely
deposited in the pit but enclosed in a water tight liner and cap, or they
can be combined with asphalt or cement to prevent leaching into the
surface and ground water environment. Table B-21 presents cost estimates
in the case where a nearby (i.e., within 10 miles) open-pit coal mine or
copper quarry is assumed to be available. Long-term radon and hydrology
control can cost as little as $6,900,000. This include only the costs
for dragline excavation of the tailings, truck and rail tailings
transport, and loose tailings disposal with an asphalt liner and cap.
These cost estimates are relatively low because it is assumed that there
is an operating open pit mine close to the mill tailings pile, and the
mine owners are willing to cover the mill tailings at no cost as part of
their post-operation reclamation of the mine site. On the other hand,
the costs may increase to $57,550,000, if the mill tailings are deposited
in an abandoned open pit mine, transported by truck, dried by a thermal
evaporator, and incorporated into an asphalt matrix. It is also assumed
B-49
-------
TABLE B-20
Costs of Residual Tailings Disposal
($1000 of 1978 dollars)
Task Cost
Earth work
Clay liner not required
Normal digging 4200
Shale 6290
Liner
Clay
With clay available 320
With clay purchase 780
Asphalt 280
Synthetic TOO
None
Tailings excavation, loading,
spreading and compacting 1500
Tailings transportation
Track 1300
Truck and rail 1100
Pipeline 1270
Stabilization
Vegetation
No need to purchase soil 130
With soil purchase 440
Irrigation equipment 30
Rip rap 2280
Gravel 450
Chemical 130
Fencing
5'-6' high chain like fence 50
Security (prison grade) fence 160
Future Costs
Irrigation equipment 100
Chemical stabilization 500
5'-6' high chain link fence 10
Security (prison grade) fence 20
Value of land 20
B-50
-------
that the disposal site is stabilized with vegetation requiring the
purchase of suitable top soil. Unlike the previous control levels,
however, there is no long-term commitment to institutional maintenance and
the site will be available for alternative future uses.
In another, it is assumed that an abandoned underground mine is
available nearby. In this case, it is assumed tht the tailings will need
to be incorporated in an asphalt or cement matrix to prevent leaching.
Furthermore, holes will be bored into the mine cavities for depositing the
asphalt or cement matrix. Cost estimates for deep disposal of the mill
tailings in an underground mine are presented in Table B-22. This method
of tailings disposal will cost at least $13,150,000, but not more than
$27,480,000 to implement.
B-51
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TABLE B-21
Cost Estimates of Deep Disposal
When a Nearby Open-pit Mine is Available
(in 1978 dollars)
Task ($1,000)
Evacuate & load tailings 1,200
Tailings transportation
Truck 1,330
Truck & rail 1,100
Pipeline 1,300
Tailings disposal
Loose with liner & cap 4,600
Cement fixation
Thermal evaporator 17,900
Filter bed 10,830
Asphalt fixation
Thermal evaporator 24,930
Filter bed 17,840
Disposal of mine contents 28,130
Vegetation cover
No need to purchase soil ___ 690
Soil purchase required 4,600
B-52
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TABLE B-22
Cost Estimates of Deep Disposal
When a Nearby Underground Mine is Available
(in 1978 dollars)
Task ($1,000)
Evacuate & load tailings 1,200
Tailings transportation
Truck 1,330
Truck & rail 1,100
Pipeline 1,300
Bore holes 20
Tailings disposal
Cement fixation
Thermal evaporator 17,900
Filter bed 10,830
Asphalt fixation
Thermal evaporator 24,930
Filter bed 17,840
B-53
-------
References for Appendix B
(DA 77) Dames & Moore, 1977, "An Evaluation of the Cost Parameters for
Hypothetical Uranium Milling Operations and Ore Transportation
Systems in the Western United States," Argonne National
Laboratory, Job No. 10263-001-07.
(DO 78) Dodge Building Cost Services, 1978, 1978 Dodge Guide for
Estimating Public Works Construction Costs, McGraw-Hill: New
York, N.Y.
(ME 77) Means, Robert Snow, 1977, Building Construction Cost Data 1977.
Robert Snow Means, Co., Inc.: Duxbury, Mass.
(NR 76) U.S. Nuclear Regulatory Commission, August 1976, "Final Generic
Environmental Statement on the Use of Recycle Plutonium in
Mixed Oxide Fuel in Light Water Cooled Reactors," NUREG-0002,
Vol. 4.
(NR 79) U.S. Nuclear Regulatory Commission, April 1979, "Generic
Environmental Impact Statement on Uranium Milling," NUREG-0511.
(SM 78) Smith, C. Bruce and Lambert, Janet A., June 1978, "Technology
and Costs for Cleaning Up Land Contaminated with Plutonium," in
"Selected Topics: Transuranium Elements in the General
Environment," U.S. Environmental Protection Agency,
ORP/CSD-78-1.
B-54
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APPENDIX C
The Proposed Standards
-------
PROPOSED STANDARDS
The Administrator of the Environmental Protection Agency hereby
proposes to add a Part 192 to Title *IO of the Code of Federal Regulations
as follows:
Part 192 - ENVIRONMENTAL PROTECTION STANDARDS FOR
URANIUM MILL TAILINGS
Subpart A — Environmental Standards for the Disposal of Residual
Radioactive Materials from Inactive Uranium Processing Sj.tes
Sec.
192.01 Applicability
192.02 Definitions
192.03 Standards
192.0*1 Effective date
Subpart B - Environmental Standards for Cleanup of
Open Lands and Buildings Contaminated with Residual
Radioactive Materials from Inactive Uranium Processing Sites
192.10 Applicability
192.11 Definitions
192.12 Standards
192.13 Effective date
C-2
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Subpart C — Exceptions
192.20 Criteria for exceptions
192.21 Remedial actions for exceptional circumstances
(Authority: Section 275 of the Atomic Energy Act of 195**, 42 U.S.C. 2022,
as amended by the Uranium Mill Tailings Radiation Control Act of 1978,
PL 95-604.)
Subpart A — Environmental Standards for Disposal of Residual
Radioactive Materials from Inactive Uranium Processing Sites
192.01 Applicability
This subpart applies to the disposal of residual radioactive material
at any designated processing site or depository site as part of any
remedial action conducted under Title I of the Uranium Mill Tailings
Radiation Control Act of 1978 (PL 95-604), or following any use of
subsurface minerals at such a site.
192.02 Definitions
(a) Unless otherwise indicated in this subpart, all terms shall have
the same meaning as in Title I of the Uranium Mill Tailings Radiation
Control Act of 1978.
(b) Remedial action means any action performed under Section 108 of
the Uranium Mill Tailings Radiation Control Act of 1978.
(c) Disposal means any remedial action intended to assure the
long-term, safe, and environmentally sound stabilization of residual
radioactive materials.
C-3
-------
(d) Disposal site means the region within the smallest practical
boundaries around residual radioactive material following completion of
disposal.
(e) Depository site means a disposal site selected under Section
104(b) or 105(b) of the Uranium Mill Tailings Radiation Control Act of
1978.
(f) Aquifer means a geologic formation, group of formations, or
portion of a formation capable of yielding usable quantities of ground
water to wells or springs.
(g) Ground water means water below the land surface in the zone of
saturation.
(h) Underground drinking water source means:
(1) an aquifer supplying drinking water for human consumption, or
(2) an aquifer in which the ground water contains less than
10,000 milligrams/liter total dissolved solids.
(i) Curie (Ci) means the amount of radioactive material which
produces 37 billion nuclear transformations per second. One picocurie
(pCi) = 10~12 Ci.
(3) Waters of the United States, including the territorial seas
means "navigable waters," as defined in the Federal Register, Volume 44,
page 32901, June 7, 1979. (Comment; This definition is taken from the
Regulations for the National Pollutant Discharge Elimination System,
40 CFR 122.3(t). In essence, it includes all surface waters which the
public may traverse, enter, or draw food from.)
C-4
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192.03 Standards
Disposal of residual radioactive materials shall be conducted in a
way that provides a reasonable expectation that for one thousand years
following disposal:
(a) The average annual release of radon-222 from a disposal site
to the atmosphere by residual radioactive materials shall not exceed
2 pCi/m2-sec, and
(b) Substances from residual radioactive materials released
after disposal to an underground drinking water source shall not cause
(1) the concentration of that substance in the ground water
to exceed the level specified in Table A, or
(2) an increase in the concentration of that substance in
the ground water, where the concentration of that substance prior to
remedial action exceeds the level specified in Table A for causes other
than residual radioactive materials.
This subsection shall apply to the dissolved portion of any substance
listed in Table A at any distance greater than 1.0 kilometer from a
disposal site which is part of an inactive processing site, or greater
than 0.1 kilometer if the disposal site is a depository site.
(c) Substances released from residual radioactive materials
after disposal shall not cause an increase in the concentration of any
substance in any waters of the United States, including the territorial
seas.
192.04 Effective date
The standards of this Subpart shall be effective 60 days from
promulgation of this rule.
C-5
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Subpart B — Environmental Standards for Cleanup
of Open Lands and Buildings Contaminated with Residual
Radioactive Materials from Inactive Uranium Processing Sites
192.10 Applicability
This subpart applies to open lands and buildings which are part of any
processing site designated by the Secretary of Energy under PL 95-604,
Section 102. Section 101 of PL 95-60H, states that "processing site"
means —
(A) any site, including the mill, containing residual radioactive
materials at which all or substantially all of the uranium was produced
for sale to any Federal agency prior to January 1, 1971 under a contract
with any Federal agency, except in the case of a site at or near Slick
Rock, Colorado, unless —
(i) such site was owned or controlled as of January 1, 1978, or is
thereafter owned or controlled, by any Federal agency, or
(ii) a license (issued by the (Nuclear Regulatory) Commission or
its predecessor agency under the Atomic Energy Act of 195*1 or by a
State as permitted under section 27^ of such Act) for the production
at such site of any uranium or thorium product derived from ores is
in effect on January 1, 1978, or is issued or renewed after such
date; and
(B) any other real property or improvement thereon which —
(i) is in the vicinity of such site, and
(ii) is determined by the Secretary, in consultation with the
Commission, to be contaminated with residual radioactive materials
derived from such site.
C-6
-------
Any ownership or control of an area by a Federal agency which is acquired
pursuant to a cooperative agreement under this title shall not be treated
as ownership or control by such agency for purposes of subparagraph (A)(i).
A license for the production of any uranium product from residual radioac-
tive materials shall not be treated as a license for production from ores
within the meaning of subparagraph (A)(ii) if such production is in
accordance with section 108(b).
192.11 Definitions
(a) Unless otherwise indicated in this subpart, all terms shall have
the same meaning as defined in Title I of the Uranium Mill Tailings
Radiation Control Act of 1978.
(b) Remedial action means any action performed under Section 108 of
the Uranium Mill Tailings Radiation Control Act of 1978.
(c) Open land means any surface or subsurface land which is not a
disposal site and is not covered by a building.
(d) Working Level (WL) means any combination of short-lived radon
decay products in one liter of air that will result in the ultimate
emission of alpha particles with a total energy of 130 billion electron
volts.
(e) Dose equivalent means absorbed dose multiplied by appropriate
factors to account for differences in biological effectiveness due to the
type and energy of the radiation and other factors. The unit of dose
equivalent is the "rem."
C-7
-------
(f) Curie (Ci) means the amount of radioactive material which
produces 37 billion nuclear transformations per second. One picocurie
(pCi) = 10-12 Ci.
192.12 Standards
Remedial actions shall be conducted so as to provide reasonable
assurance that —
(a) The average concentration of radium-226 attributable to residual
radioactive material from any designated processing site in any 5 cm
thickness of soils or other materials on open land within 1 foot of the
surface, or in any 15 cm thickness below 1 foot, shall not exceed 5 pCi/gm.
(b) The levels of radioactivity in any occupied or occupiable
building shall not exceed either of the values specified in Table B
because of residual radioactive materials from any designated processing
site.
(c) The cumulative lifetime radiation dose equivalent to any organ of
the body of a maximally exposed individual resulting from the presence of
residual radioactive materials or byproduct materials shall not exceed the
maximum dose equivalent which could occur from radium-226 and its decay
products under paragraphs (a) and (b) of this section.
192.13 Effective date
The standards of this Subpart shall be effective 60 days after
promulgation of this rule.
C-8
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Subpart C — Exceptions
192.20 Criteria for exceptions
Exceptions to the standards may be justifiable under any of the
following circumstances:
(a) Public health or safety would be unavoidably endangered in
attempting to meet one or more of the requirements of Subpart A or
Subpart B.
(b) The goal of environmental protection would be better served by
not satisfying cleanup requirements for open land, Sec. 192.12(a) or the
corresponding part of Sec. 192.12(c). To justify an exception to these
requirements there should be a clearly unfavorable imbalance between the
environmental harm and the environmental and health benefits which would
result from implementing the standard. The likelihood and extent of
current and future human presence at the site may be considered in
evaluating these benefits.
(c) The estimated costs of remedial actions to comply with the
cleanup requirements for buildings, Sec 192.12(b) or the corresponding
part of Sec. 192.12(c), are unreasonably high relative to the benefits.
Factors which may be considered in this judgment include the period of
occupancy, the radiation levels in the most frequently occupied areas, and
the residual useful lifetime of the building. This criterion can only be
used when the values in Table B are only slightly exceeded.
(d) There is no known remedial action to meet one or more of the
requirements of Subpart A or Subpart B. Destruction and condemnation of
buildings are not considered remedial actions for this purpose.
C-9
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192.21 Remedial actions for exceptional circumstances
Section 108 of PL 95-604 requires the Secretary of Energy to select
and perform remedial actions with the concurrence of the Nuclear Regulatory
Commission and the full participation of any State which pays part of the
cost, and in consultation, as appropriate, with affected Indian tribes and
the Secretary of the Interior. Under exceptional circumstances satisfying
one or more of the conditions 192.20(a), (b), (c), and (d), the Department
of Energy may select and perform remedial actions, according to the proce-
dures of Sec. 108, which come as close to meeting the standard to which
the exception applies as is reasonable under the exceptional circumstances.
In doing so, the Department of Energy shall inform any private owners and
occupants of affected properties and request their comments on the selected
remedial actions. The Department of Energy shall provide any such comments
to the parties involved in implementing Sec. 108 of PL 95-604. The
Department of Energy shall also inform the Environmental Protection Agency
of remedial actions for exceptional circumstances under Subpart C of this
rule.
U.S. Environmental Protection
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TABLE A
Arsenic 0.05 milligram/liter
Barium 1.0 milligram/liter
Cadmium 0.01 milligram/liter
Chromium 0.05 milligram/liter
Lead 0.05 milligram/liter
Mercury 0.002 milligram/liter
Molybdenum 0.05 milligram/liter
Nitrate nitrogen 10.0 milligram/liter
Selenium 0.01 milligram/liter
Silver 0.05 milligram/liter
Combined radium-226 and radium-228 5.0 pCi/liter
Gross alpha particle activity (including
radium-226 but excluding radon and uranium) 15.0 pCi/liter
Uranium 10.0 pCi/liter
TABLE B
Average Annual Indoor
Radon Decay Product Concentration
(including background) • 0.015 WL
Indoor Gamma Radiation
(above background) 0.02 milliroentgens/hour
C-ll
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U.S. Environmental Protection Agency
Region V, Library
230 South Dearborn Street
Chicago, Illinois 60604 x^
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