EPA CONTRACT NO. 68-0 1-4490
URANIUM
MINING &
MILLING
THE NEED, THE PROCESSES,
THE IMPACTS, THE CHOICES
ADMINISTRATOR'S GUIDE
SS>
Western Interstate Energy Board
-------
URANIUM MINING & MILLING; '
THE NEED, THE PROCESSES, THE IMPACTS, THE CHOICES
ADMINISTRATOR'S GUIDE
Prepared for
WESTERN INTERSTATE ENERGY BOARD/WINS
(formerly the Western Interstate Nuclear Board)
2500 Stapleton. Plaza, "• " '""••'- •
3333 Quebec .Street,,,. .... : ...
Denver,. .Colorado ":,'8020:7 "Y- ' ".''•-•..
'>, •' .•..•' •"*• '...-••' ' • r ' -•-.- -
Under Contract to the .. - v\.
United States Environmental Protec'tion Agency
Contract No. .68-01-44:90 -V.\""-' ' ".
.by
Stone & Webster Engineering Corporation
Denver, Colorado
• •-•-May* 1978 ' ...:•-..• ."'^/ 't
-------
Disclaimer
This report: was prepared as an
account of work sponsored by the
United States Government. Neither
the United States, nor the SPA, nor
Western Interstate Energy 3oard/r,NlNB
nor Stone S Webster Engineering
Corporation nor any of their
employees, nor any of their
contractors, suhcon-rac-ors, or
their employees acting on iehalf of
either;
a. makes any warranty,
expressed or implied, as
to the accuracy, com-
pleteness or .usefulness
of any information, appa-
ratus, product or process
disclosed, or represents
that its use would not
infringe privately owned
rights; or
fa. assumes•• any liability
with respect to the use
of or ' for damages re-
sulting from the use of
any information, appa-
ratus, method or process
disclosed in tihis report.
-------
EPA- 908 /.I -,7 8 -
URANIUM MINING & MILLING
THE NEED, THE PROCESSES, THE IMPACTS, THE CHOICES
ADMINISTRATOR'S GUIDE
Prepared for
WESTERN INTERSTATE ENERGY BOARD/WINB
(formerly the Western Interstate .Nuclear Board)
2500 Stapleton Plaza
3333 Quebec Street
Denver, Colorado .. 80207
Under Contract to the ••'
United States Environmental Protection Agency
Contract No. 68-01-4490,
by
Stone & Webster Engineering Corporation
Denver, Colorado
May 1978
-------
Disclaimer
This report was prepared as an
account: of work sponsored by the
United States Government. Neither
the United States, nor the EPA, nor
Western Interstate Energy Board/'-NlNB
nor Stone S Webster Engineering
Corporation nor any of their
employees, nor any of
contractors, subcontractors, or
their employees acting en behalf of
either;
a. makes any warranty,
expressed or implied, as
to the accuracy, com-
pleteness or .usefulness
of any information, appa-
ratus, product or process
disclosed, or represents
that its use would not
infringe privately owned
rights; or
b. assumes any liability
with respect to the use
of or for damages re-
sulting from the use of
any information, appa-
ratus, method or process
disclosed in -chis report.
-------
Acknowledgements
The Administrator's Guide was
prepared for the Western Interstate
Energy Board/WINB (formerly the
Western Interstate Nuclear Hoard) by
Stone & Webster Engineering
Corporation (SWEC) under the
sponsorship of the Environmental
Protection Agency's (EPA) Region
VIII Energy Office, Denver,
Colorado. The Colorado School of
Mines Research Institute (CSMRI)
provided the basic technical
information in Chapter 3 on uranium
mining and milling. Dr. Ward
Whicker and Dr. James Johnson",
Consultants and Professors at the
Department of Radiation Biology at
Colorado State University,
contributed to the radiological
information in Chapter 4. The
Denver Research Institute (DRI)
developed Chapter 5, Socioeconomic
Considerations. Mr. Paul Smith, EPA
Project Officer, and Mr. Ross
Scarano of the Nuclear Regulatory
Commission's Nuclear Material Safety
and Safeguards Group provided
guidance on approach and content.
The Project Steering Committee of
WISB/WINB chaired by Dr. Richard
Turley provided valuable review and
comments.
The work began under the direction
of Mr. Wyatt Rogers, Jr., former
Executive Director of WIEB/WINB,
continued with the assistance of Mr.
Fred Gross, and was completed under
the direction of Mr. John Watson,
the current WIEB/WINB Executive
Director.
-------
SOURCE; Adapted from EPA
GUAM
PUERTO RICO
Regional Offices
United States Environmental Protection Agency
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Table of Contents
1 INTRODUCTION 1-1
1.1 PURPOSE OF THE GUIDE 1-1
1.2 ORGANIZATION AND CONTENT 1-2
1.3 URANIUM MILL LICENSING 1-4
1.4 COMMENTS AND UPDATING 1-5
2 NUCLEAR POWER AND URANIUM RESOURCES 2-1
2.1 THE NEED FOR URANIUM 2-1
2.1.1 Projected Generation by Energy Sources 2-1
2.1.2 Growth of Nuclear Power 2-5
2.1.3 Uranium Requirements 2-6
2.2 URANIUM SUPPLY 2-10
2.2.1 Uranium Ore Reserves 2-11
2.2.2 Uranium Resources 2-15
2.2.3 Future Uranium Production Centers 2-22
REFERENCES 2-26
BIBLIOGRAPHY 2-27
3 MINING AND MILLING URANIUM ORE 3-1
3.1 URANIUM RESOURCE DEVELOPMENT 3-1
3.1.1 Steps Prior to Mining and Milling 3-2
3.1.2 Methods to Mine and Process Uranium Ore 3-3
3.2 URANIUM MINING 3-6
3.2.1 Mining Method Selection 3-6
3.2.2 Underground Mining 3-10
3.2.3 Surface Mining 3-14
3.2.4 Bore-Hole Mining 3-17
3.3 URANIUM PROCESSING METHODS 3-19
3.3.1 Conventional Acid Leaching 3-21
3.3.2 Conventional Alkaline Leaching 3-27
3.3.3 In-Situ Leaching (Solution Mining) 3-30
3.3.4 Heap Leaching 3-37
3.3.5 Other Methods 3-40
3.3.6 Processing Methods at U.S. Uranium
Mills 3-41
3.3.7 Future Trends in Yellowcake Production 3-43
v
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TABLE OF CONTENTS (CCNT'D.)
3.4 PRODUCTION COSTS 3-46
3.4.1 Resource .Requirements 3-46
3.4.2 Capital and Operating Costs 3-49
3.5 MILL TAILINGS MANAGEMENT . 3-54
3.5.1 Performance Objectives 3-55
3.5.2 Site Selection For Tailings
Impoundments 3-56
3.5.3 Current Tailings Disposal Practice 3-59
REFERENCES . 3-68
4 ' SITING AMD ENVIRONMENTAL IMPACT 4-1
4.1 REGULATIONS, STANDARDS AND GUIDELINES 4-2
4.1.1 Regulatory Authority 4-2
4.1.2 Regulatory Procedures and Permit
Requirements 4-7
4.1.3 Proposed Legislation and Requirements 4-8
4.2 FACTORS AFFECTING FACILITIES SITING 4.-11
4.2.1 Topography 4-12
4.2.2 Population 4-13
4.2.3 Geology and Geochemistry 4-14
4.2.4 Hydrology 4-15
4.2^5 Soils and Overburden 4-17
4.2.6 Meteorology 4-19
4.2.7 Biology 4-21
4.2.8 Seismicity 4-23
4.2.9 Cultural Features 4-23
4.3 NON-RADIOLOGICAL IMPACTS 4-24
4.3.1 Land Use 4-25
4.3.2 Topography 4-27
4.3.3 Surface and Ground Water 4-27
4.3.4 Air Quality 4-33
4.3.5 Biology and Soils 4-37
4 RADIOLOGICAL IMPACTS . 4-39
4.4.1 Movement of Radionuclides in the
Environment 4-44
4.4.2 Accidental Releases 4-50
4.4.3 Biological Effects of Radiation Dose 4-52
4.4.4 Control of Radioactive Waste 4-53
4.5 RECLAMATION, STABILIZATION AND
DECOMMISSIONING 4-54
4r5t.j. Reclamation 4-55
4.5,2 Stabilization 4-59
4,5.3 Decommissioning 4-63
VI
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TABLE OF CONTENTS (CONT'D.)
4.6 MONITORING AND SURVEILLANCE PROGRAMS . 4-64
4.6.1 Preoperational Monitoring 4-65
4.6.2 Operational Monitoring • 4-68
4.6.3 Post-Reclamation Surveillance 4-72
REFERENCES 4-74
APPENDIX
A-1 Radionuclides of the Uranium Decay
Series 4A-1
A-2 Radionuclide Transport and Exposure
Pathways 4 A-4
A-3 Prediction of Radiation Dose 4A-6
A-4 Radiation Dose Rates and Their
Significance 4A-7
5 ' SOCIOECONOMIC CONSIDERATIONS 5-1
5.1 DIRECT IMPACTS ON EMPLOYMENT AND
INCOME 5-7
5.1.1 Employment 5-8
5.1.2 Income 5-11
5.2 INDIRECT AND INDUCED IMPACTS ON
EMPLOYMENT AND INCOME 5-15
5.2.1 Non-Basic Economic Activity ' 5-15
5.2.2 Analytical Approaches 5-16
5.3 POPULATION CHANGES 5-18
5.3.1 Settlement Patterns 5-19
5.3.2 Prediction Techniques 5-20
5.4 PUBLIC SERVICES AND PUBLIC FINANCE 5-22
5.4.1 . Revenues 5-24
5.4.2 Expenditures 5-27
5.4.3 Public Finance Constraints 5-28
5.5 HOUSING AND COMMERCIAL DEVELOPMENT 5-31
5.5.1 Housing 5-32
5.5.2 Commercial Development 5-34
5.6 SOCIO-CULTURAL AND POLITICAL CHANGES 5-37
5.6.1 Sccio-Cultural Changes 5-39
5.6.2 Political and Demographic Changes 5-40
5.7 OTHER POTENTIAL CONFLICTS 5-41
5.8 CONTINGENCY PLANNING AND MONITORING
PROGRAMS 5-43
Vll
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TABLE OF CONTENTS (CONT'D.)
REFERENCES ' 5-45
BIBLIOGRAPHY 5-46
GLOSSARY G-1
Vlll
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List of Tables
CHAPTER 2
2-1 Projected Generation of Electric Power From
Principal Energy Sources 2-2
2-2 Summary of Uranium Production, Reserves and
Potential Resources By Regions 2-16
2-3 Distribution of $30 Per Pound 0308 Potential
Uranium Resources By State as of 1/1/77 2-20
2-4 Summary of Surface Drilling for Uranium 2-21
CHAPTER 3
3-1 Process Variations at U.S. Uranium Mills 3-7
3-2A Process Variations at Operational U.S. Uranium
Mines and Mills 3-42
3-2B Process Variations Proposed for Future U.S.
Uranium Mines and Mills 3-44
3-3 Economics of Conventional Mining and Milling 3-51
3-4 Economics of Solution Mining 3-53
CHAPTER 4
4-1 Status of Approvals and Permits Required for
the Sweetwater Project as of November 1977 4-10
4-2 Approximate Land Requirements (in acres) for
Various Mine and Mill Activities 4-26
4-3 Typical Airborne Emissions from Uranium Mills 4-34
4-4 Estimated Emissions from Heavy Equipment at
Surface and Underground Mines 4-35
4-5 Summary of Typical Radiation Dose Rates from
the Natural Environment in the Wyoming Area 4-41
4-6 Comparison of Annual Dose Commitments to
Individuals with Radiation Protection
Standards 4-43
IX
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LIST OF TABLES (CONT'D.)
4-7 Estimated Airborne Release Kates of Radio-
nuclides from Model Uranium Mills in New Mexico
and Wyoming 4-48
4-8 Operational Monitoring Program 4-69
CHAPTER 4 APPENDIX
A-1 Calculated Exposure Rates for Radionuclides
Uniformly Distributed in Soil '4A-9
A-2 Total Maximum Annual Radiation Dose to
Individuals from an Operating Mill in New
Mexico 4A-10
A-3 Total Maximum Annual Radiation Dose to
Individuals from an Operating Mill in Wyoming 4A-11
A-4 Radiation Dose Commitment to Individuals from
the Bear Creek Project 4A-13
A-5 Radiation Dose Commitments to Individuals
(mrem/yr) for the Sweetwater Project 4A-14
A-6 Estimated Short-Term Radiation Exposures
Required to Damage Various Plant Communities 4A-15
A-7 Summary of Estimates of Annual Whole-Body
Dose Rates in the United States (1970) . 4A-16
A-8 Dose Rates Due to Internal and External
Irradiation from Natural Sources in "Normal"
Areas 4A-17
CHAPTER 5 •
5-1 Factors Influencing the Occurrence of
Socioeconomic Impacts 5-4
5-2 Estimates of Work Forces for Selected Uranium
Mines and Mills 5-9
5-3 Changes in Worker Productivity 5-11
5-4 Average Monthly Salary Ranges for Selected
Areas 5-13
5-5 Examples of Average Wages for Uranium Industry
Workers .. 5-14
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LIST OF TABLES (CONT'D.)
5-6 Examples of Utah Taxes to be Paid by Uranium
Mining and Milling Companies 5-25
5-7 Estimated Major Utah Taxes to be Paid by a
Hypothetical Uranium Mine-Mill Complex 5-26
5-8 Indicators of Societal Change - Converse
County, Wyoming 5-38
XI
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List of Figures
United States Regional Offices Environmental
Protection Agency iv
CHAPTER 2
2-1 Electric Generation By Principal Energy
Sources In Contiguous United States 2-3
2-2 U.S. Uranium Production Capability 2-7
2-3 U.S. Uranium Production Capability vs.
Requirements 2-7
2-4 Distribution of $30 Per Pound U30a Reserves
as of 1/1/78 in major districts 2-12
2-5 U.S. Reserves of $30 Per Pound U308 by States
(1/1/78 Preliminary) 2-13
2-6 Regions of the National Uranium Resource
Evaluation (NURE) Program 2-17
2-7 National Uranium Resources Evaluation (NURE) -
Potential Uranium Resource Areas 2-18
2-8 Significant Exploration Activities, 1977 2-19
2-9A Class 1 and Class 2 Production Centers
in the United States - $30.00 per pound U30a 2-24
2-9B Class 3 and Class 4 Production Centers
in the United States - $30 per pound U3Oa 2-25
CHAPTER 3
3-1 Steps In Uranium Resource Development 3-4
3-2 Steps Common To Most Processing Methods 3-5
3-3 Room-and-Pillar Mining 3-13
3-4 Typical Open Pit Mining Method 3-16
3-5 Hypothetical Bore-Hole Mining System 3-18
3-6 U3Oa Extraction By Sulfuric Acid Leaching 3-22
3-7 U30a Extraction By Alkaline Leaching 3-28
3-8 Well and Well Field Design For Solution Mining 3-33
xii
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LIST OF FIGURES (CONT'D.)
3-9 Typical Well Field Pattern ' 3-34
3-10 U30a Extraction By Solution Mining 3-36
3-11 Typical Construction for Heap Leaching 3-38
3-12 Methods of Tailings Dam Construction 3-64
CHAPTER 4
4-1 Transport and Movement of Radionuclides to Man 4-45
CHAPTER 4 APPENDIX
A-1 The Primary Decay Series of Uranium - 238 4A-2
GLOSSARY
G-1 The Light Water Reactor Fuel Cycle G-5
Kill
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INTRODUCTION
CHAPTER t
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CHAPTER 1
Introduction
1.1
Purpose of the Guide
During the past decade, -here has been increased concern about
the environmental impacts of uranium mining and milling. In
response to these concerns, improved methods have been developed
to reduce or mitigate undesirable impacts. The Administrator's
Guide is intended to meet the need for a single document that
provides current information about these concerns and
developments, particularly with respect to siting and operating
uranium facilities. It focuses on those factors that require
adoption of methods to prevent contamination of the environment,
limit exposure to radioactivity, and mitigate long-term and
short—term adverse effects, including socioeconomic impacts.
The primary objective of the Guide is to address the technical,
economic, social, and environmental factors that influence
uranium mining and the siting of milling facilities in the
western United States. Although the Guide is not a regulatory
document, the information should be useful to local, state, and
federal adminstrators, legislators, policy makers, planners, and
regulators involved in the review or approval process for uranium
projects. The information should also be of interest to citizens
who would be affected by a proposed project.
1-1
-------
The Guide also highlights information that is considered by
industry during the planning process. For example, site-specific
aspects of mill tailings management are receiving increased
attention from regulators and industry, and some earlier tailings
disposal practices are no longer acceptable. To assure that the
Guide will be useful to the uranium industry, comments from the
Project Steering Committee (which includes mine and mill
operators) were considered.
A. secondary objective of the Guide is to inform developers of the
various options that may be available when planning uranium
development projects. Although the location of the mine is
fixed, there are options available in the design of the mill,
such as alternative sites, process methods, waste disposal
locations and pollution control techniques.
1.2
Organization and Content
The Guide covers three important aspects of uranium resource
development:
Why and where uranium resource development is likely to
occur
• How ore is mined and processed
How environmental and social considerations relate to
siting, licensing and operating new or expanded facilities
1-2
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The focus of the Guide is on the third aspect listed.
Accordingly, uranium resource development and mining and milling
technology are treated to the level required to establish a basis
for the more detailed discussions of siting and environmental
impacts and socioeconomic considerations which follow. Each
chapter is independent of the others so that the reader may go
directly to the material of interest and not have to refer to
sections in other chapters. The information in the Guide is
basically limited to uranium mining and milling, the initial
steps in the nuclear fuel cycle. A description of the fuel cycle
and a simplified diagram of the activities necessary to fuel a
nuclear power reactor and dispose of the wastes produced are
presented in the Glossary.
The material is organized as follows:
Chapter 2- "NUCLEAR POWER AND URANIUM RESOURCES." This
chapter summarizes information prepared by the
Department of Energy (DOE). The need for
uranium for existing and future nuclear
generating stations is discussed. Estimates of
the uranium industry's production capability and
data for known ore reserves and potential
uranium resources are included. Additionally,
areas with favorable uranium geology that may be
the site of new or increased activity are shown.
Chapter 3- "MINING AND MILLING URANIUM ORE." A generalized
perspective of uranium mining and milling
technology is presented. Project lead times and
relative costs are compared for a conventional
mine and mill complex and an in— situ (solution
mining) operation. Engineering techniques for
mill tailings management are included.
1-3
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ORGANIZATION, Continued
Chapter 4- "SITING ANE ENVIRONMENTAL IMPACT." Those
factors affecting uranium mines and the site
specific conditions which influence location of
mills are described. The biological, chemical,
and radiological impacts that occur during
development, operation, and post-reclamation are
discussed.
Chapter 5- "SOCIOECONOMIC CONSIDERATIONS." The social and
economic costs and benefits associated with
uranium resource development are reviewed and
summarized. The positive and negative impacts
of development on employment, income, . and
population are discussed. Jurisdictional
problems, competition for labor and land, and
the stress on public services and finance are
analyzed. The opportunity and timing of
mitigation and growth management strategies are
reviewed. Selected data from New Mexico,
Wyoming, and Utah -are presented to illustrate
growth—induced impacts and mitigation practices
in regions experiencing rapid development.
1.3
Uranium Mill Licensing
The Guide refers to many of the licensing and. regulatory
requirements that apply primarily to uranium mines and mills.
The licensing process is complex, and specific requirements for a
uranium project vary from state to state. Timely coordination
with regulatory authorities and an understanding of their
requirements are essential to projec-c scheduling and planning.
Such coordination must include federal, state and county
officials.
1-4
-------
One major distinction in licensing uranium mills (and any other
facility where ore is processed) is in the role of the Nuclear
Regulatory Commission (NRG) and the states. The provisions of
the Atomic Energy Act of 1954, as amended, provide for states . to
enter into agreement with the NRC and perform as the regulatory
authority. Those states which have been delegated licensing
authority are called "agreement" states. Those states in which
the NRC maintains its authority are called "non-agreement"
states. The information on this subject and a list of pertinent
regulations and guidelines are included in Section 4.1 of
Chapter 4.
1.4
Comments and Updating
The information in the Guide was compiled from many sources. It
has been carefully reviewed by representatives of government and
industry to eliminate errors or inconsistencies and to update
information obtained from the literature when appropriate.
Readers are invited to submit comments to:
U. S. Environmental Protection Agency
Region VIII
1860 Lincoln Street
Denver, CO 80295
Attention Mr. Paul B. Smith
1-5
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In the future, significant progress is expected to improve waste
disposal practices and impact mitigation techniques for siting,
design and construction of new uranium mines and mills. The
Guide is in looseleaf form so that its usefulness may be extended
by future revisions to reflect the results of this progress.
1-6
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NUCLEAR POWER AND URANIUM RESOURCES
CHAPTER 2
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CHAPTER 2
Nuclear Power and Uranium Resources
2.1
The Need for Uranium
The need for uranium in the future will te determined by the
contribution of nuclear power to the domestic and world energy
supply. The generating capacity of new nuclear power plants is
the subject of continuing study, and differing energy supply and
demand scenarios have been projected. Increased exploration
activity and mine and mill expansion and/or development clearly
indicate that the domestic and international uranium industry is
expecting significant growth in electric generation capacity from
nuclear reactors. A recent study maintains that "the reactors
now under construction will result in an increase in demand for
fuel in excess of existing supply" and that "the fuel supply
industry... must increase capacity in a major way during the next
10—20 years under the most pessimistic future nuclear plant order
assumptions" (Nucleonics Week, March 16, 1978} .
2.1.1
Projected Generation by Energy Sources
The . National Electric Reliability Council (NERC) has projected
the amount of electric power that will be generated from
2-1
-------
principal energy sources from 1977 through 1986, as shown on
Table 2—1 below and in Figure 3—1. The NEKC projections are
especially useful in that they are revised annually to reflect
utility-Industry plans. The 1977 forecasts indicate a compound
annual growth rate of 5.7 percent for the next ten years. The
National Energy Plan (NEP) projects a similar rate of total
energy consumption for industrial use at more than 5 percent a
year through 1985 (NERC, July 1977) .
Table 2-1
Projected Generation of Electric Power from Principal Energy Sources
Nuclear
Coal
Oil
Gas
Hydro
Total
Net Electrical Energy Generated
(Million KWHR)
1977
281,211
1,009,851
350,189
238,240
232,915
1986
989,000
1,698,164
458,163
93,751
238,256
2,112,406 3,477,344
Source: NERC, August 1977.
Total Change
1977 to 1986
+35255
+ 168%
+ 131%
2%
+ 164%
2-2
-------
KILOWATT HRS
TRILLIONS
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
KILOWATT HRS
TRILLIONS
4.0
1986
/ 27.7%
" NUCLEAR
1977 /
'
47. 5%
COAL
46.9%
17.1%
OIL
14.6%
1_1_J%
10.8% HYDRO 6.7%
2.
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
SOURCE: NERC, August 1977.
* Other energy sources include
diesel, geothermal and undesignated.
These sources account for 0.4% in
1977 and 0.7% in 1986.
Figure 2-1
Electric Generation by Principal Energy Sources in Contiguous United States.
2-3
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In 1976 nuclear power represented 8 percent of the installed
generating capacity in the U.S..and accounted for 9.7 percent
of electricity produced. NERC's projected increase from about
13 percent in 1977 to about 28 percent in 1986 represents an
increase in nuclear energy production of three and one—half
times in one decade (NERC, August 1977).
Nuclear generation data from the Department of Energy (DOE),
Energy Information Administration (EIA), differs slightly from
NERC data but show that nuclear power contributed 11.7 percent
in 1977 to total electricity generation as compared to
9.4 percent in 1976 (DOE, EIA, February 1978).
Other NERC projections are as follows:
• Coal fired generation will nearly double from 1977 to 1986
and will average about 47 percent of . electric energy
production.
• Oil fired generation will continue at 17 percent through
1982 and decrease to less than 15 percent in 1986. Oil
consumption will increase, however, from 631 million
barrels in 1977 to 878 million barrels in 1986. Oil
consumption will rise as it replaces natural gas.
• Gas fired generation will decline from 2.6 billion
thousand cubic feet (MCF) to 1.1 billion MCF.
• Hydro generation will increase slightly but decrease in
percentage to about 7 percent by 1986.
V J
Most of the requirements for fuel for new base load capacity to
be added by 1986 have been determined.
2-4
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2.1.2
Growth of Nuclear Power
Nuclear electric power is expected to resume its growth and to
significantly increase its share of the U.S. energy supply
despite current institutional and regulatory constraints. Light
water reactors (LWR's) will probably supply most of the nuclear
generation capacity in the short term and during the early years
of the twenty—first century.
Although forecasts for future growth of the nuclear power differ,
most agree on continued growth in the industry. The National
Energy Plan (NEP) proposed by the Administration in April 1977
projects U.S. installed nuclear capacity as follows:
Year
1976
1985
1990
2000
Nuclear Capacity
MW(e)
42,000
127,000
195,000
380,000
According to the NEP, the nuclear power capacity will increase at
the rate of 16 percent per year through 1985 and 7.3 percent from
1985 through 2000. An industry survey of reactor commitments
shows reactor generation capacity of 159,964 MW(e) in 1985 and
193,591 MW(e) in 1990 (Electrical World, January 15, 1978).. If
these commitments by industry are realized, the NEP projection
will be exceeded by about 33,000 MW (e) in 1985 and within
1,400 MW(e) of that projected for 1990.
2-5
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2.1.3
Uranium Requirements
The total requirement for uranium through the year 2000 and for
30 more years thereafter is nearly 3 million tons D30a« The
uranium requirements for the 380,000 MW(e) projected in the year
2000 would be a little more than 1 million tons, using the
present light-water reactors without reprocessing spent fuel.
The 30—year lifetime requirements for this 380,000 MW(e) would be
on the order of 2 million tons (U.S. DOE, December 1977). About
5000 to 8000 tons of uranium (0308) is required to fuel a
1000 MW(e) light-water reactor during its operating life (Boyd,
1977) .
Uranium Production Capability
The DOE has estimated both the uranium industry's production
capability and production capability versus requirements. In
making these estimates, the DOE differentiates between ore
reserves and potential resources. It also defines three
categories of potential resources:, "probable," "possible," and
"speculative." These terms, as well as the basis of the costs,
are defined in the Glossary.
The estimated capability of the uranium industry is based on the
maximum annual tonnages that could be produced from S30/lb
uranium reserves through the year 2000, as seen on Figure 2—2.
Industry production and planned capacity is within the limits of
reserves to about 1984; after that, production may be from
probable potential resources (Nininger, 1978).
2-6
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80
60
40
20
MAXIMUM PRODUCTION CAPABILITY
FROM $30 RESOURCES
PROJECTED PRODUCTION
CASED ON COMPANY PLANS
(Includes production from facilities
existing, under construction or
pub Iicly announced)
Under Construction
Current FaciIi ties
^—Exports
1977 1980 '
1985
1990
Figure 2-2
U.S. Uranium Production Capability
From Reserves
1995
2000
SOURCE: Nininger, 1978
80
60
40
20
TAILS ASSAY ASSUMED AT:
•70% THROUGH FY 80
-25S THEREAFTER
Maximum CaqaBility
(Less Exports)
„ 380G»e
Net Requi rements
Current Contracts
Maximum Contract Re!ief
Company Plans
1977 1980
1985
1990
1995
Figure 2-3
U.S. Uranium Production Capability vs. Requirements
2000
2-7
-------
The estimated uranium production capability versus requirements
in the U.S. to the year 2000 are shown on Figure 2—3. In this
figure, the maximum production capability (less exports) is
compared with the net uranium requirements, based on uranium
enrichment contracts with utilities (Nininger, 1978).
The requirements for current enrichment contracts are near the
industry's production capability estimated for the early 1980's.
Several companies have plans as yet unannounced according to DOE,
which could increase production during this period. However, if
the use of nuclear power increases as predicted in the
administration's National Energy Plan, a production shortage will
occur in the mid 1990's (Nininger, 1978). Production
requirements would be met by expansion of low-cost reserves and
potential resources or by use of higher cost material, in the $30
to $50 per pound category.
The costs used by the DOE are called "forward costs" (see
Glossary) and do not by definition equate to market price
directly. For example. Collieries Management Corporation
indicates the price of OaOa, in 1978 dollars, will be
»$49.20-$60.80 in 1980; $79.20-$100.80 in 1985; and
$86.70-$110.20 in 1990." (Nucleonics Week, iMarch 16, 1978.)
Breeder Reactors May Extend Uranium Resources
A breeder reactor produces more fuel than it consumes, and thus
could extend uranium resources. However, breeder reactors are
not likely to be available to lessen the short-term uranium needs
of LWR's.
2-8
-------
An alternative to the breeder is the Canadian Natural Uranium
Reactor (CANDU), which reportedly can obtain 20 to 40 percent
more energy from uranium than a LWR. Other reactor development
concepts which do not require highly enriched uranium are being
investigated to limit proliferation of nuclear material.
Uranium Enrichment
Almost 90 percent of the world's present and planned nuclear
generating capacity requires slightly enriched uranium as fuel
(Keeny at al., 1977). The enrichment process requires that the
U30a be converted to uranium hexafluoride (UF6), which is the
input (feed) for the process. Natural uranium contains about
0.7 percent of the fissionable isotope 23SU. Enrichment
increases the concentration of this isotope to approximately
3 percent, which is necessary to provide fuel for a light-water
reactor.
Commercial quantities of enriched uranium are produced by
government-owned gaseous diffusion plants. These plants are
energy intensive. At full capacity the plants require 6,1000 MW
of electrical power (NRC GESMO, NUREG-0002, Vol. 3, 1976). The
plants not only produce the enriched UF6 product but also UF6
that is depleted in "SU, called tails. The tails assay,
expressed as the percentage of 23SU, at which an enrichment plant
is operated, depends upon availability of uranium feed, plant
capacity, and power availability. In 1980 the government will
operate at an increased tails assay. At that time, the
percentage will increase to 0.25 percent from 0.2 percent.
2-9
-------
Because of the increase in the tails assay, the overall
requirements for U30a concentrate will increase more than
20 percent (Keeny et al., 1977).
Recycling (Reprocessing)
There is now a moratorium on recycling spent fuel from LWR's.
Domestic uranium reserves would be extended ty recycling spent
fuel (Boyd et al., 1977). Although recycling would ease demand,
there would be a shortfall in the supply of uranium.
2.2
Uranium Supply
Estimates of domestic uranium reserves and resources follow.
U30a/ Millions
of Short Tons
Reserves [known] 0.7 all that is certain
Probable maximum 3.7 upper planning limit
Prudent planning base 1.8-2.0
Source: (Culler, 1977)
Estimates of known reserves total about 680,000 tons, and
probable resources may add 1.1 million tons, resulting in a
1.8 million ton prudent planning base. The 3.7 million tons
include possible and speculative resources yet to be located
(Culler, 1977).
2-10
-------
2.2.1
Uranium Ore Reserves
DOE estimates of domestic ore reserves are based largely on data
furnished by industry. These data consist primarily of gamma-ray
logs of drill holes and other ore deposit sampling information. .
The majority of uranium reserves in the United States are in
sandstones of the Mesozoic and Tertiary ages in the following
comparatively small areas:
• Grants mineral belt of New Mexico
« Tertiary basins in Wyoming
• Gulf Coastal Plain in Texas
• Paradox Basin in Colorado and Utah
• Spokane area in Washington
The DOE has estimated the amount of- uranium that can be exploited
for a forward cost of $30/lb. The location of these reserves and
the estimated amount of uranium oxide within each reserve are
shown on Figure 2—4.
2-11
-------
I-1
N>
g 2000-6000 TONS
I. N Black Hills
I. S Black HIM*
3. Sand lash Basin
^ 9000-10.000 TONS
4. Front Range
5. Marshall Pass
6. Duval
O 10.000-30.000 TONS
7. Spokane
8. Paradox Basin
Over 30.000 TONS
0. lyoBing Basin
10. Kerns-Live Oak
II. Grants Mineral Belt
Significant Net Discoveries
12. Date Creek
13. Tallahassee Creek
SOURCE: Adapted Iron Ueehan. 1877
Figure 2-4
Distribution of $30 Per Pound UaOa Reserves as of 1/1/77 in Major Districts
-------
Arizona
Colorado
Utah
*OTHER STATES
California
Idaho
Montana
Nevada
North Dakota
Oklahoma
Oregon
South Dakota
Washington
SOURCE: Nininger, 1978
STATE
New Mexico
Wyoming
Texas
Ariz, Colo, Utah
Other
Total (rounded)
THOUSANDS
TONS U308
364
207
47
52
20
690
%
53
30
7
7
3
100
Figure 2-5
U.S. Reserves of $30 Per Pound UaOs by States (1/1/78 Preliminary)
2-13
-------
Each ore body must be able to support the total forward operating
and capital costs in order to be recognized as a reserve. A more
comprehensive discussion of forward costs, ore reserve
categorization and estimation methodology is given by Meehan
(1977). The distribution of U.S. uranium reserves as of
January 1, 1977 for the $30/lb forward cost category is given on
Figure 2-5.
Additions to reserves are likely to be in, or extensions of,
presently-known producing districts, mostly in Wyoming and New
Mexico. New Mexico accounts for approximately 50 percent of the
uranium produced in the U.S. (Nininger, 1978). The New Mexico
Environmental Improvement Agency (NMEIA) expects 15 new uranium
mills to become operational in New Mexico in the next few years.
Nine new mines are in the development stage and 13 more have been
proposed (Rocky Mountain Energy Summary, January 23, 1978.) Many
of the proposed developments will be in the San Juan Basin north
of the Grants mineral belt.. In northeastern Wyoming, the
Sundance project is reported to have potential yellowcake
reserves "in the 50 million pound vicinity believed to be
economically recoverable by solution mining techniques."
(Nucleonics Week, January 12, 1978.)
Other significant new discoveries are being developed in Arizona
at Date Creek and the central Colorado Rockies at Tallahassee
Creek (Meehan, 1977). Also, plans were announced for a uranium
mine to be operating near Bakersfield, California, by fall 1978.
Proven reserves total about 162,000 pounds in hard rock, not
sandstone. According to reports by Portland General Electric
2-14
-------
geologists, potential reserves within 3 miles of the mine may
total 5—10 million pounds (Nucleonics Week, March 2, 1978).
2.2.2
Uranium Resources
The location of new uranium-producing districts and the extent to
which thay will be developed are of primary interest to those who
may be affected by uranium activities. Table 2—2 shows the
locations of potential uranium resources and estimates of how
much ore these resources may yield. Figure 2—6 is a map of
National Uranium Resource Evaluation reporting regions. Table
/•
2—3 tabulates the amount of 530/lb uranium by state. Figure 2—7
shows the location of potential uranium areas.
The DOE resource classifications, which reflect the differences
in the reliability of the resource estimates, are listed in the
Glossary. Additional information on estimates of ore reserves
and potential resources is given in the "Statistical Data of the
Uranium Industry," which is compiled by the Grand Junction Office
of DOE.
Surface Drilling Activities
The rise in the price of uranium and the increased demand for
uranium supplies have stimulated exploration in the U.S.
Exploration activities have increased dramatically since 1972,
and the amount of surface drilling for uranium in 1977 was the
highest ever.
2-15
-------
Region
Colorado Plateau
Wyoming Basins
Coastal Plain
Northern Rockies
Colorado and Southern Rockies
Great Plains
Basin and Range
Pacific Coast and Sierra Nevada
Central Lowlands
Appalachian Highlands
•Columbia Plateaus
Southern Canadian Shield
Alaska
TOTAL
Tons U..OQ
Production
to 1/1/77
206,400
63,600
8,900
16,500 •
<1,000
<1,000
<1,000
<1,000
0
<1,000
296,400
Tons t^Og
1/1/77
Reserves
378,
210,
43,
20,
9,
6,
10,
1,
680,
000
100
900
000
400
300
900
400
0
0
0
0
0
000
1/1/77
Probable
545
300
115
27
46
23
29
4
1
1,090
,000
,000
,000
,000
,000
>000
,000
,000
*
*
*
*
,000
,000
($30/lb.)
Potential Resources
Possible
610
50
60
63
38
59
228
12
1,120
,000
,000
,000
,000
,000
,000
,000
,000
*
*
*
*
*
,000
Speculative
90,000
30
25
49
20
37
51
8
71
78
21
480
,000
,000
,000
,000
,000
,000
,000
,000
,000
,000
*
*
,000
*Resources not estimated because of inadequate knowledge.
SOURCE: Hetland, 1977
Table 2-2
Summary of Uranium Production, Reserves, and Potential Resources by Regions
-------
Pacific
Coast I
Sierra
Nevada
Columbia)j Northern
Pliteaus f Rockies
Southern Canadian Shield
ppalachian
Highlands
Basin
I Range
Central Lowland
) Coastal Plain!
L
SOURCE: Hetland.1977
Figure 2-6
Regions of the National Uranium Resource Evaluation (NURE) Program
-------
to
•i
OP
Legend
Probable & Possible
Potential Areas
Speculative Potential Areas
SOURCE: Adapted from Hetland, 1977
Figure 2-7
National Uranium Resource Evaluation (NURE) Potential Uranium Resource
Areas
-------
• M
CD
SANDSTONE
12.
13.
14.
16.
M-
23.
SI Montana
HIIlliton Basin
Southirn Black Hills
Powder River Basin
Great Divide Basin
Denver Basin
Henry Mountains
Paradoi Basin
Tallahassee Creek
San Juan Basin
Rio Grande Trench
South Texas
3.
5.
ID.
II.
15.
Owl Creek Mtns
Central Black Hills
Thomas Range
Toiybe Range
San Juan Utns
IB.
19.
20.
21.
22.
24.
25.
26.
22
Sierra Ancha
Date Creek
Uojave Desert
Seward Peninsula
Prince of Wales Island
Grandfather Mountain
Reading Prong
N Michigan
Figure 2-8
Significant Exploration Activities, 1977
SOURCE: Adapted from Chenoweth. 1877
-------
State
Probable
Possible
Speculative
Alaska
Arizona
Arkarsas
California
Colorado
Connecticut
Idaho
Montana
Nevada
New Jersey
New Mexico
North Carolina
North Dakota
Oklahoma
Oregon
Pennsylvania
South Dakota
Texas
Utah
Washington
Wyoming
TOTAL
1,000
37,000
—
11,000
101,000
—
—
—
4,000
—
398,000
• —
7,000
—
7,000
—
7,000
117,000
77,000
9,000
314,000
50,000
—
10,000
82,000
—
5,000
7,000
13,000
—
466,000
—
9,000
—
21,000
—
4,000
60,000
270,000
23,000
100,000
11,000
1,000
8,000
37,000
9,000
31,000
43,000
14,000
9,000
77,000
17,000
—
65,000
7,000
45,000
5,000
54,000.
5,000
15,000
27,000
1,090,000
1,120,000
480,000
Table
SOURCE: Hetland, 1977
Distribution of $30 Per Pound UaOs Potential Uranium Resources by State
as of 1/1/77
2-20
-------
Most of the exploration is concentrated in the vicinity of the
major uranium-producing districts. Wyoming, New Mexico, Texas,
Colorado, and Utah accounted for 92.7 percent of the surface
drilling in 1977 (Nininger, 1978). Significant 'exploration
activities in 1977 reported by DOE are shown on Figure 2—8.
Surface drilling statistics given in Table 2-4 show the rapid
expansion of exploration and development drilling since the low
point, in 1971.
Table 2-4
Summary of Surface Drilling for Uranium
AVE.
MILLIONS THOUSANDS
YEAR
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
OF FEET OF
24
30
24
15
15
16
22
27
35
40
Source: Nininger,
V
HOLES
30
58
76
59
39
37
34
40
67
94
1978
HOLE
DEPTH
IN FEET
410
394
400
398
421
480
550
457
506
434
PERCENT-
EXPLORATION
DRILLING
68
69
76
74
78
66
73
65
57
.64
PERCENT
DEVELOPMENT
DRILLING
32
31
24
26
22
34
27
35
43
36
J
2-21
-------
Other Exploration Activities
Industry and DOE have recently increased their exploration
activities, such as geologic mapping and geochemical and
geophysical surveying, in new areas. The success of exploration
in frontier areas remains to be demonstrated (Chenoweth, 1977).
Production from Lower Grade Ores
Production estimates for 1985—1990 are difficult to project
because of the problems with development of lower-grade uranium
ore. Yellowcake production in 1977 was estimated as, 15,000 short
tons (Kahn, 1977) from ore of a higher grade than would be
expected in the 1980's and 1990's. Development of future uranium
supplies will be tied directly to world-wide demand.. The selling
price of uranium oxide extracted from lower-grade ores is
expected to be higher.
2.2.3
Future Uranium Production Centers
The DOE Supply Analysis Division has analyzed existing, expanded,
and proposed uranuim mining and milling capabilities in the U.S.
The production centers are shown on Figures 2—9A and 2—9B. The
DOE projections should prove helpful to planners in that the
projections are for a relatively long time span.
2-22
-------
The production capabilities are an upper limit estimate of how
much uranium the industry could produce. It appears that the
estimate does not include financing or licensing constraints that
might alter mine development or mill construction schedules.
Production centers were classified according to certainty of
future production. The classifications are excerpted as follows
(Klemenic et al., 1977):
• CLASS 1 CENTERS include the existing mills with supporting
mines and other facilities at which concentrate was being
produced at the time the capability estimate was made.
Ownership of the facilities and tributary sources can
readily be identified. Production costs can reasonably be
defined, and future production is well assured.
• CLASS 2 CENTERS include uranium mills and supporting
resources for which construction commitments are evident
and mine .development has been announced or is underway.
Class 2 centers are generally converted to Class 1 centers
within three years.
• CLASS 3 CENTERS are uranium mills in regions where the
amount and grade of reserves justify production but where
mill construction is not yet evident. Three to five years
are estimated for mine and mill installation.
• CLASS 4 CENTERS are possible centers postulated for areas
in which present reserves are insufficient to support
production facilities but where exploration and/or
geologic evidence has indicated sufficient "probable"
potential resources to warrant the assumption of eventual
production. The assummed lead time to develop reserves
and construct mining and milling facilities for Class 4
centers generally ranges from 6 to 22 years and averages
14 years. Consolidation of land holdings is a long lead-
time item.
2-23
-------
iaPr"i7
I L rA—».
r ^3o429 T~-i
CLASS t PRODUCTION CENTERS'
1. The Anaconda Company
2. Atlas Corporation
3. Conoco & Pioneer Nuclear, Inc.
4. Cotter Corporation
S. Dawn Mining Company
6. Exion Company, U.S.A.
7. Federal American Partners
8. Intercontinental Energy Corp.
9. Kerr-McGee Nuclear Corp.
10. Lucky Me Uranium Corporation
It. Lucky le Uranium Corporation
12. Modi I Oil Company
13. Rie Algoei Corporation
14. Rocky Mtn. Energy Company
15. Sohio Oil-Reserve Oil
16. Union Carbide Corporation
17. Union Carbide Corporation
18. United Nuclear Corporation
19. United Nuclear Hoaestake-
Partntrs
20. Uranium Recovery Corp.
21. U.S. Steel
22. U.S. Steel-Mi agra Mohawk
23. Western Nuclear. Inc.
24. Wyoming Mineral Corporation
Grants. New Mexico
Hvab. Utah
Falls City, Texas
Canon Rity, Colorado
Ford, Washington
Powder River Basln,Wy«
Gas Hills, Wyoming
Pawnee, Texas
Grants, New Mexico
Gas Hills, Wyoming
Shirley Basin, fyo
Sruni, Texas
La Sal, Utah
Sear Creek, lyo
Ljguna, New Mexico
Gas Hi I Is. Wyoming
Uiavan, Colorado
Church Rock, N.M.
Grants, New Mexico
Mulberry, Florida
Seoige West, Texas
George West, Texas
Jeffrey City, Wyoming
Bruni & Ray Point, Texas
2 PRODUCTION CENTERS
25. Chevron Resources Company
26. Farmland Industries, Inc
27. Freeport Uranium Recovery Co
2B. Gardinier, Inc
29. Gulf Mineral Resources Co
30. Hones take Mining Company
31. Kerr-BcGes Nuclear Corp
32. Mineral Exploration Company
33. Pttrotoaics Company
34. Phillips Petroleum Company
33. Durita Development Company
36. Solution Engineering, Inc
37. United Nuclear Corporation
38. Western Nuclear, Inc
39. Wyoming Mineral Corp
40. Wyoaing Mineral Corp
Panna Maria, Texas
Pierce, Florida
Uncle Sam, Louisianna
Tampa, Florida
San Mateo, New Mexico
Marshall Pass, Colo
Powder River Basin,Wyo
Red Desert, Wyoming
Shirley Basin, Wyo
Nose Rock, New Mexico
Naturita-Qurango, Col
Falls City. Texas
Morton Ranch, Wyoming
Wellpinit, Wash
Binghan, Utah
Powder River Basin,Wyo
SOURCE: Adapted from Klemenic, 1977
Figure 2-9A
Class 1 and Class 2 Production Centers in the United States
$30 Per Pound UaOs
2-24
-------
•'ar
CLASS 3 PRODUCTION CENTERS
41. Artillery Peak
42. Cleveland-Cliffs Iron Co
43. CroM Point
44. East Crooks Gap
45. Edgeorant
46. Pioneer Nuclear, Inc
47. Rampant Exploration, Corp
48. Rio Grande Trench
49. Rocky Mountain Energy Co
O
CLASS 4 PRODUCTION CENTERS
50. Baggj
51. Caaeron
52. Cast
53. Fernley
54. Likevie*
55. Karysvale
56. Mountain City
57. It. Taylor
SB. N€ Great Divide Basin
53. North Black Hills
80. Ship rock
St. Sierra Aacha
Other Capper Operations By-Product
Other Phosphate By- Prod.
Arizona
Pumpkin Butte.Vyo
Ne» Rexico
Vyoning
South Dakota
Utah
Tal lahassee Creek, Col
Men Mexico
Copper Mtn.lyo
fyoning
Arizona
California
Nevada
Sr egon
Utak
Nevada
Ne« Mexico
tyoning
South Dakota
N«i Mexico
Arizona
Restern U.S.
S£ t I U.S.
SOURCE: Adapted from Klemenic, 1977
Figure 2-9B
Class 3 and Class 4 Production Centers in the United States
$30 Per Pound LbOs
2-25
-------
CHAPTER 2
References
Boyd, James and .L. T. Silver. United States Uranium Position.
Paper presented at the ASME—IEEE Joint power Generation
Conference, Long Beach, California, September 18—21, 1977.
Chenoweth, William L. Exploration Activities. Paper presented
at the Uranium Industry Seminar, Grand Junction, Colorado,
October 1977.
Culler, F. L. An Alternate Perspective on Long Range Energy
Options. Conference on U.S. Oprions for Long Term Energy
Supply, Denver, Colorado, June 20, 1977. Atomic Industrial
Forum Program Report Vol. 3, No. 10, n.d.
Hetland, Donald L. and Wilbur D. Grundy. Potential Resources.
Paper presented at the Uranium Industry Seminar, Grand
Junction, Colorado, October 1977.
Kahn, M. L. "Uranium." Mineral Commodity Summaries 1978,
pp 182 and 183. U.S. Department of the Interior, U.S. Bureau
of Mines, n.d.
Xeeny, Spurgeon M., Jr. (Chairman). Nuclear Power Issues and
Choices. Report of the Nuclear Energy Policy Study Group,
Cambridge, Massachusetts: Ballinger Publishing Company, 1977.
Klemenic, John and David Blanchfield. Production Capability
and Supply. Paper presented at the Uranium Industry Seminar,
Grand Junction, Colorado, October 1977.
Meehan, Robert J. Ore Reserves. Paper presented at the
Uranium Industry Seminar, Grand Junction, Colorado, October
1977.
National Electric Reliability Council. 7th Annual Review of
Overall Reliability and Adequacy of the North American Bulk
Power Systems: A Report by Interregional Review Subcommittee
of the Technical Advisory Committee, July, 1977.
National Electric Reliability Council. Fossil and Nuclear Fuel
for Electric Utility Generation Requirements and Constraints,
1977-1986, August 1977.
2-26
-------
Nininger, Robert D. Remarks at Atomic Industrial Forum "Fuel
Cycle '73" Conference, New York, New York, March 7, 1978.
U.S. Department of Energy. DOE Role in Nuclear Policies and
Programs, Official Transcript of Public Eriefing: Addendum,
December 1977.
U.S. Department of Energy. Energy Information Administration.
Monthly Energy Review, Fehuary 1978.
U.S. Nuclear Regulatory Commission. Final Generic Environ-
mental Statement on the Use of Recycle Plutonium in Mixed
Oxide Fuel in Light Water Cooled Reactors (GESMO).
NUREG-0002, Vol. 3, August 197/6.
Bibliography
Brown, R. w. and R. H. Williamson. Domestic Uranium
Requirements. Paper presented at the Uranium Industry
Seminar, Grand Junction, Colorado, October 26, 1977.
Davis, W. Kenneth (Chairman-Session 1). Session 1: New Energy
Policy from a New Administration. Introductory Comments at
the Conference on U.S. Options for Long Term Energy Supply,
Denver, Colorado, June 19—22, 1977. Atomic Industrial Forum,
Program Report, Vol. 3, No. 10, n.d.
Edison Electric Instititute. 1977 Annual Electric Power
Survey. A Report of the Electric Power Survey Committee of
the Edison Electric Institute, April 1977.
Rathjens, George. Address to the Atomic Industrial Forum,
Denver, Colorado. Paper presented at the Conference on U.S.
Options for Long Term Energy Supply, Denver, Colorado,
June 20, 1977, Atomic Industrial Forum, Program Report,
vol. 3, No. 10, n.d.
2-27
-------
MINING AND MILLING URANIUM ORE
CHAPTERS
-------
CHAPTER 3
Mining and Milling Uranium Ore
Uranium development projects must operate within the framework of
acceptable mining and milling technology. General understanding
of the current state of this technology is necessary in order to
compare siting options and development processes in respect to
environmantal and socioeconomic concerns. Current practices in
mining and milling uranium ores are summarized under the
following topics:
Overview of uranium resource development
Uranium mining
Uranium processing methods
Production costs
Mill tailings management
3.1
Uranium Resource Development
Successful uranium resource development depends upon
comprehensive planning prior to mining and milling. The
following sections briefly discuss the planning steps and provide
an overview of the common processing stages and methods.
3-1
-------
3.1.1
Steps Prior to Mining and Milling
Once a uranium ore body has been located and the necessary
permits and licenses have been obtained, exploration drilling is
followed by development drilling to determine the grade, size,
depth and shape of the deposit. The drilling provides samples
which are analyzed to identify the physical and chemical
properties of the ore. Samples from the deposit are also tested
to determine the. process necessary to extract uranium from the
ore and recover the material as a marketable product. Site
surveys and preliminary mine—planning studies are usually
conducted simultaneously with the process development
investigation. A series of coordinated site—surveys is performed
to provide data relative to soil mechanics, hydrology,
topography, meteorology, vegetation and wildlife, public health
and sanitation, labor resources, transportation and available
sources of material and equipment. Assuming the ore responds
favorably to treatment, the data collected from the process
development studies and site surveys are used to conduct
preliminary mill—engineering studies and to determine the
economic feasibility of the project. If the economics appear
favorable, financing is arranged, environmental factors are
assessed, a mill site is selected and detailed engineering is
initiated (O'Rourke and Whelan, 1968).
Developing a uranium prospect is similar to developing other
mineral deposits except that regulatory controls are strictly
enforced by the NEC or one of the agreement states in accordance
with the Atomic Energy Act of 1954 as amended. Accordingly, many
3-2
-------
federal, state and local government agencies must be consulted,
and ultimately their approval to proceed must be obtained. The
licensing and permitting process may result in long lead times
for development of uranium properties.
After licenses, permits and approvals are secured, construction
of the mine-mill complex begins. Development usually requires
several years to complete. The exact development route followed
by companies will vary, but a simplified program is illustrated
on Figura 3—1.
3.1.2
Methods to Mine and Process Uranium Ore
A variety of methods are employed by the industry to mine and
process uranium ore. Most methods have several steps in common.
As illustrated on Figure 3—2, the uranium-bearing ore is mined
and transported to the processing facility. The ore is crushed
and ground to expose the uranium minerals on the surface of
barren host—rock particles. The ground ore is pulped with water,
and chemicals are added to dissolve the uranium. The dissolved
uranium is separated from the leached residue, and the uranium-
bearing liquor is treated by selective chemical techniques to
yield a uranium-rich product liquor. The uranium is precipitated
from this liquor, dried and shipped to enrichment plants.
One . notable exception to this general mining-milling scheme is
the in—situ extraction of uranium from intact ore bodies. This
technique is relatively new to the mining industry, and
relatively few deposits are presently treated in this manner.
Basically, in—situ extraction (solution mining) involves drilling
3-3
-------
STEP
UJ
. Locate and secure mineral claims
Obtain permits and licenses
Exploratory drilling
Development drilling
Process-development studies
Geotechnical site surveys
Preliminary planning and
engineering of mine
Economic feasibility analysis
Financing
Environmental assessment
Mill site selection
Detailed design and engineering
of mine and mill
Construction
YEARS ^
12 3 A 5 6 7 8 9 10
Figure 3-1
Steps in Uranium Resource Development
SOURCE: Adapted from CSMRI, 1978
-------
Mining
Crushing
Grinding
Leaching
Liquid-Sol id
Separation
(residue)
Concentration
(product Iiquor)
Precipitation
Dewater ing
Drying &
Packaging
URANIUM
PRODUCT
SOURCE: CSMRi
Figure 3-2
Steps Common to Most Processing Methods
3-5
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a series of wells into a permeable uraniferous aquifer, injecting
a leaching agent into the wells, and pumping the uranium-bearing
solution to the surface for further treatment and recovery of the
U308 (See Figure 3—8). This eliminates the costly steps of
mining, crushing, and grinding and reduces the above-ground
deposition of mill tailings. However, the long term impact of
in—situ extraction on ground water and the methods to effectively
restore solution-mined aguifiers to premining or to acceptable
water quality are being studied.
Table 3—1 lists the process variations for open pit and
underground mines and for solution mining.
3.2
Uranium Mining
Uranium mining methods fall within the categories of underground
mining, surface mining, and bore-hole mining. The preferred
method is the one that requires the least cost per pound of ore
recovered while remaining within the constraints of many
technical, environmental, and regulatory factors,
3.2.1
Mining Method Selection
Selection of the mining method is based on a detailed geologic,
engineering and economic analysis of the ore deposit. Factors to
be considered are the ore body's size, grade, host—rook
mechanics, location, depth, geometry and engineering properties.
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Open-Pit Mines
Development drilling
Stripping
Mine waste*
Vaste dump
Develop ore faces
Drill, blast*
Load
Haul
Crush
Grind*
Leach uranium
Liquid-solid separation
U_00 concentration
3 o
Precipitate, dry, package
Tailings dam operations
Reclamation
16
Underground Mines
Development drilling
Shaft sinking
Development drifting
Vaste dump*
Develop stopes
Drill, blast
Muck out
Haul
Hoist
Haul to mill
Crush*
Grind*
Leach uranium
Liquid-solid separation
U,00 concentration
J Q
Precipitate, dry, package
Tailings dam operations
Reclamation
18
Solution Mining
Development drilling
Drill wells
Leach uranium
Pump solution to mill
Liquid-solid separation
UJDg concentration
Precipitate, dry, package
Recirculate leach
solutions
Aquifer restoration
Total stages to produce a saleable product
SOURCE:
Adopted from
Hunkin, October,
1975
NOTE:
* Denotes stages generally producing
significant changes in or affecting
land surfaces, water quality, personnel
safety or radiation exposure.
Table 3-1
Process Variations at U.S. Uranium Mines and Mills
3-7
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Size and Grade of the Ore Body
The boundaries of naturally occurring uranium deposits are seldom
easily defined, and the mineralization grade usually varies from
barren to mineralized rock. Although methods for selective
mining are available, it is still impossible to distinguish
completely between barren and mineralized material. The mining
plan is based on information from development drilling and
normally contains an allowance for dilution of the ore during
mining.
Unit costs for moving ore and waste are normally less in a
surface operation than for underground mines because the larger
machines used are more efficient and productivity is greater. As
a result, surface mining is preferred whenever the ore body is
sufficiently large and close to the surface so that waste removal
costs (stripping ratio) are not excessive.
Geographic Location of the Ore Body
The location of an ore body is a major factor in making the
decision to proceed with mine design and evaluation. If an ore
body is located within a specially designated public land (e.g.,
a wilderness area), mining may not be allowed. As more public
lands are reserved for special uses, (e.g., the Alaska
Wilderness) the number of the potential uranium reserves
available for development is reduced.
3-8
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Depth and Geometry of the Ore Body
Depth and geometry of the ore body have a definite impact on the
mining method selected. Open pit uranium mining is practiced to
depths of 400 feet, but the grade of the ore and the size of the
deposit dictate the practical depth of a surface mine. Small,
high-grade deposits can often be mined more efficiently by
underground methods even though they may be located within a few
hundred feet of the surface. A large blanket-type deposit could
oe more easily mined by open-pit methods even if depths are
equivalent.
Engineering Properties of the Ore and Waste
Mine design must take into account the engineering properties of
the ore, waste rock, and material surrounding the ore deposit (s).
Underground mining requires sufficient rock strength and
competency to economically prevent failure of mine walls, roofs
and pillars. In surface mining, rock strength determines the
slope of the pit walls required to maintain slope stability.
The presence of ground water may reduce rock strength by
increasing pore pressure in the material. The result may be the
failure of the surrounding rock and a cave-in in an underground
mine or flooding and wall collapse in a surface mine. Ground
water may also soften shale beds, allowing pillars in an
underground mine to punch into the surrounding rock, resulting in
a roof fall. Intrusion of large volumes of ground water into an
underground or surface mine requires costly pumping and treatment
3-9
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systems; for example, the Mt. Taylor mine in New Mexico has a
13,000—gpm capacity pumping system (Jackson, 1977}.
3.2.2
Underground Mining
Underground mining has the advantage of selectivity. The only
waste materials removed are those associated with the ore body or
from adits, access tunnels and shafts. On the other hand,
because underground mining methods are costly, they are selected
only whan other methods are impractical, such as when the ore
body is at too great a depth for surface development. Also,
underground mining is more labor-intensive because of confined
work spaces and smaller capacity machines used. Special
provision must be made for access, haulage systems and
ventilation.
Access
In an underground mine, access to the ore is generally by means
of a vertical shaft, a sloped incline or decline, or a relatively
level tunnel or adit. Tunnels are generally preferred because
they can be driven so that natural drainage will occur and ore
haulage is less difficult. However, tunnels are only feasible
where .topography allows the portal to be located at an elevation
near that of the ore body. Typical examples of tunnel or adit
access are the underground mines of the Federal-American Partners
in the Gas Hills of Wyoming and the older workings of the
Schwartzwalder Mine in Colorado.
3-10
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A vertical shaft project is being constructed at Mt.
Taylor, New Mexico, by Gulf Mineral Resources Co.
(Jackson, 1977). The ore body is approximately 3,200 feet
below the surface of the ground in an area of relatively
flat terrain. Two vertical, concrete-lined shafts at a
maximum depth of 3,300 feet will provide access to the ore
body and sumps for mine water that must be pumped to the
surface and ventilation. The shafts are 400 feet apart.
A 24—ft diameter main shaft will provide a hoisting
capacity of 4,500 tpd from the ore body by means of two
skips powered by a 2,500—hp double drum hoist. The main
shaft also serves as the air exhaust for the mine. A
smaller, 14—ft diameter shaft serves as the intake shaft
for ventilation and provides access for men and materials.
Mine Transportation
Mine transportation or haulage systems are required to move ore
and wastes out of the mine or to the bottom of the shaft and to
move men and supplies into the mine. Typically, conveyor belts,
rubber-tired trucks or rail systems are used. Truck and rail
systems are preferred in uranium mines. The advantages of each
system are compared in Dwosh, (1978).
Tunnels and drifts are usually driven in waste rock so that
extraction of the ore and subsequent subsidence will not damage
the mine transportation and ore haulage systems. The tunnels and
drifts also provide conduits for the ventilation system.
Ventilation
The mine ventilation system must remove all fumes from equipment,
explosions, etc., and must also reduce dust and radon gas
concentrations to below regulatory levels. Ventilation
requirements vary from state to state, and careful attention to
ventilation system design is required.
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Room-and-Pillar Mining
A common mining method in tabular ore bodies is called the room-
and-pillar method, illustrated on Figure 3—3. There is a high
degree of flexibility in room-and-pillar mining.. Work is done by
equipment sections. A section might consist of a wheel or
crawler type of loader, drill, and one or more rubber-tired
trucks or buggies to haul the ore. The successful use of this
type of equipment depends upon having a sufficient number of
working places so that each machine can be rotated from place to
place as its function is completed. This requires a sufficient
number of working places in a reasonably confined district and
close supervision on the part of the section foreman.
Thinning or thickening of the ore body, barren zones and poor
roof conditions may be handled easily by the room and-pillar
method. When the ore body is quite regular, the rooms and
pillars are uniform in size and equally spaced as previously
shown. However, when the ore body is irregular, as is the case
in most uranium deposits, a system of room-and-random-pillar
mining is generally used. Pillars are generally left whenever
waste material is encountered, but if ore pillars must be left,
they may be recovered just before the mine is abandoned when
caving of the stopes is no longer a problem.
Open Room With Random Pillar Mining
Mining of ore by the open room with random pillar method begins
on either an outcrop (rare occurrences at this late date for new
mines) or at an ore intercept in an exploration hole at the
3-12
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•Ore Ready to Load
SOURCE: CSMRI
•Loading Machine
•Roof Bolting Machine
•Dri11 ing Machine
Blasting
Ore Ready
to Load
Figure 3-3
Room-and-Pillar Mining
3-13
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terminus of the drift or entry. Development then generally
progresses along the ore trend with attempts being made to stay
in ore. As the ore bodies broaden beyond 20 feet wide, and
depending on roof conditions, pillars are left in waste or low
grade ore, if possible.
A typical example of a small open room with random pillar
uranium mine is the Deremo Mine operated by Union Carbide
(Harvey, 1977). The Deremo Mine is located on the
Colorado-Utah state line approximately 64 miles from the
Four Corners and about 80 miles road distance from Uravan.
The mine workings cover an area 8,500 feet in the north-
south direction by 6,500 feet in the east-west direction.
The Deremo Mine is being serviced through three vertical
shafts about 750 feet deep. A three-compartment timbered
shaft named the Deremo No. 1 was sunk in 1957, and the
first ore was hoisted in 1958. As mining advanced to the
south, additional hoisting facilities were needed, and in
1967, the Deremo No. 2 and the Snyder shafts were put into
operation. These consisted of 64—inch diameter holes
drilled from the surface and lined with a 48—inch metal
casing. The annulus is filled with cement. Four—inch
heavy-duty pipe was welded to the casing, and this serves
as a shaft guide for the skips as well as for compressed
air and water lines. The haulage system at the Deremo
Mine was originally rail, but by 1971 it had been
converted from track to trackless haulage.
A total of 103,000 tons of ore and 90,000 tons of waste
was removed from the mine during 1976. All loading and
hauling of muck from the face to shaft station is done
with rubber-tired trackless equipment. Drilling is
accomplished with compressed air-driven push-feed drills.
The rock is broken with conventional explosives. The
average output for production crew personnel is 24 tons of
ore and waste per man-shift and for all mine personnel is
6.9 tons per man-shift.
3.2.3
Surface Mining
Frequently, • an ore body is large enough and close enough to the
surface that it may be mined by surface or open-pit methods. An
3-14
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example of surface mining in flat terrain is shown on .figure 3—4.
Unit operations are the same as for underground mining; however,
the auxiliary requirements are not as complex, and the overall
operation is generally less costly.
\
Generally, an extremely large excavation is required to get at a
fairly small tonnage of ore. In many uranium mines, from
10 to 20 tons of waste must be removed for each ton of ore mined
and occasionally, the stripping ratio may exceed 30 to 1.
Stripping ra-ios of up to 80:1 could be encountered
(Goodier, 1978).
Rock breakage in open pits is often accomplished with
conventional drilling and blasting methods, but in uranium mines
the strata are frequently soft enough so that crawler tractor
mounted rippers may be used. Rock loading may be done by shovels
or front-end loaders or by self-propelled scrapers. Haulage is
accomplished by trucks or scrapers. Frequently, mine fleets
include a- number of each of these units.
Surface mining methods are used in uranium mines in the Gas Hills
i
and Shirley and Powder River Basins in Wyoming, Laguna District
of New Mexico and in south Texas, and in several areas in
Colorado and Utah. A number of excellent papers on open-pit
mining describe operations in these states (Wood, 1977; White,
December, 1975; "Conquista...", Mining Engineering, 1972).
3-15
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Uranium Ore
Limits of Pit Floor
Mine
Limits
Pit Benches
High Grade
Mill Run
Low Grade
PLAN VIEW
•Ground Surface
-Beginning Pit
Waste Rock
(Overburden)
Final Pit
Uranium Ore
SOURCE: Adapted from CSMRI
CROSS SECTION
Figure 3-4
Typical Open Pit Mining Method
3-16
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A typical open-pit mine is the Utah International
Inc.'s Lucky Me, located in the Gas Hills of Wyoming.
Wheel tractor scrapers push-loaded by bulldozers were
the initial machines used for the overburden removal.
However, as pit depths increased, a shift to shovel or
loader and truck fleets were used because of the more
favorable machine-to-payload weight ratios obtained
with trucks.
Ore trends at Lucky Me are quite narrow, sinuous and
discontinuous. Therefore, when the stripping operation
is within about 10 feet of the ore horizon, great
caution must be exercised to avoid loss of ore. Very
thin cuts of waste are taken with the scrapers as the
ore body is approached, and each cut is supervised by
grade-control personnel. As the ore is exposed, it is
cleaned by dozers or loaders until a large exposed lump
of ore remains on the pit floor.
Mining of the ore is accomplished with a backhoe of
2 1/4 to 2 3/8 cubic yard capacity. Ore is loaded into
20— or 35—ton trucks for transport out of the pit.
Mining is controlled by grade-control personnel
equipped with Geiger counters which detect the gamma
radioactivity associated with uranium daughter products
in the mineralized ore.
Mine reclamation is playing an increasingly important role in the
feasibility, planning and economics of open pit mining. State
regulations and their enforcement vary from state to state. .
3.2.4
Bore-Hole Mining
Bore hole mining differs from solution mining in that the ore is
actually broken up in—place and removed from the bottom of the
bore .hole by fluid flow. Figure 3—5 depicts a hypothetical bore-
hole mining arrangement. A series of bore holes is first drilled
into the ore body, and then a steel pipe is used to lower a
high—pressure .horizontal nozzle into the hole, and water is
pumped at high pressure into the ore body. The high pressure
water breaks up the ore and puts it into a slurry. The slurry is
3-17
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Collection
Tank
Uranium Recovery
Plant
Install ing
Bore Hole
Mining
SOURCE: Adapted from Lang & Archibald, 1976
BackfiII ing
Mined-out Cavities
Figure 3-5
Hypothetical Bore-Hole Mining System
-------
pumped from the bore-hole to a mill for processing via a
collection tank. Tailings from the . mill are pumped into the
mined-out cavities in the ore body as backfill. Bore-hole mining
is being tested in various mining applications but this technique
is currently not in commercial use in the uranium industry.
3.3
Uranium Processing Methods
Uranium ore processing methods include:
• Conventional acid leaching
• Conventional alkaline leaching
• In—situ leaching (solution mining)
• Heap leaching
• Recovery of uranium as a byproduct
V J
Comparison of Acid and Alkaline Leaching
Uranium is recovered from the ore by dissolution in a liquid
medium, commonly called leaching. In order to increase the rate
of uranium dissolution, the pH of the leaching solution is either
decreased (acid) or increased (alkaline), depending on the
characteristics of the ore. Acid leaching is generally more
effective than alkaline leaching for treating difficult ores-.
Acid treatment usually requires less leaching time and lower
temperatures and provides more flexibility to deal with changing
ore characteristics than is possible with an alkaline process.
3-19
-------
Also, acid leaching usually does not require grinding the ore to
as fine a size as does alkaline processing. In acid circuits,
however, a substantial portion of the leaching solution must be
rejected to tailings after the uranium is removed because soluble
impurities tend to concentrate excessively.
In contrast, alkaline leaching is more selective for uranium
minerals so that leaching solutions contain fewer impurities.
Because of the relatively pure solutions, direct precipitation of
yellowcajce often is feasible without solution purification, and
leaching solutions may be regenerated and recycled with less
problems due to impurity buildup. Alkaline solutions are
relatively noncorrosive and are very suitable for treating high
lime ores which would consume large quantities of acid.
Leaching Agent Determination
The characteristics of the ore and the relative process economics
will determine the leaching reagent best suited to a particular
ore. The -predominant 'factors in this decision are reagent
consumption and the maximum uranium extraction obtained with the
particular leach liquor (Merritt, April 1977). .Sulfuric, nitric,
hydrochloric and other acids may be used for leaching, but
sulfuric acid is used almost exclusively due to cost and
corrosion factors. Usually, mixtures of ammonium carbonate and
ammonium bicarbonate solutions are used for solution mining.
Environmental considerations may also influence lixiviant
selection, especially for solution mining operations. Federal
and state agencies have placed strict requirements for restoring
3-20
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the water in a uraniferous aquifer to its original state, and
thus many solution mining operators may find it necessary to
select a leaching solution based on these environmental
regulations. Of particular concern with ammonium carbonate
solutions is the residual ammonia level in mined aquifers.
3.3.1
Conventional Acid Leaching
The majority of the uranium ores treated in the U.S..today are
processed in conventional sulfuric acid leaching mills. In its
simplest form, the typical sulfuric acid mill reduces the size of
the ore, leaches the ground pulp to dissolve the uranium,
purifies the uranium-bearing solution and precipitates the
yellowcaJce from the purified solution. A typical flowsheet for
an acid leaching mill is shown on Figure 3—6.
Crushing and Grinding
Coarse ore is retrieved from storage pads and fed to the crushing
circuit. The primary crusher reduces the size of the ore to
2 to 6 inches in diameter, while the secondary crusher further
reduces the size of the ore to 1/8 to 1/2 inch. The product from
the crusher circuit is fed to rod or ball mills where water is
added, and the.ore is ground finer to liberate the uranium
minerals from waste constituents, thereby rendering the uranium
minerals susceptible to chemical attack. In general, most acid
leaching mills grind the ore to 28 mesh, but the size of grind
may vary from 10 to 200 mesh.
3-21
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Ore from Receiving Pads
Primary Crushing
solution
Clarification
Secondary Crushing
.Grinding
Leaching
Liquid-Sol id
Separation
residue
Concentration
Precipitation
Oewatering
Drying &
Packaging
YELLOW CAKE
recycle solution
& water
Tai I ings Pond
SOURCE: CSMRI
Figure 3-6
LbOs Extraction by Sulf uric Acid Leaching
3-22
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Semiautogenous Mills
A relatively recent trend is to replace mechanical secondary
crushers and rod mills with semiautogenous grinding mills. The
semiautogenous mills eliminate the need for fine ore storage and
simplify the problems associated with wet and frozen ore. The
primary crushing circuit is not necessarily an integral part of
the main plant.
Leaching
From the grinding circuit, the ore slurry is pumped to the
leaching circuit. Sulfuric acid and an oxidant, such as sodium
A
chlorate, are added to the pulp to dissolve the uranium. Acid
leaching is usually accomplished in mechanically agitated tanks
arranged in series, but air agitated tanks. (Pachucas) are also
used. Leaching times vary from 4 to 30 hours, and leaching
temperatures range from ambient to 90 degrees Centigrade. Acid
and oxidant requirements depend on the mineralogy of the ore and
the concentration of free acid required to dissolve the uranium.
Liqui'd-Solid Separation
The next stage in the milling process is to separate the uranium-
bearing solution from the spent ore residue. Basically, the
liquid-solid separation may be accomplished by countercurrent
decantation (CCD) in thickeners of by separating the sand and
slime fractions of the pulp followed by treating the slime
portion in a CCD or resin-in-pulp (RIP) circuit.
3-23
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The majority of the acid-leaching mills operating today use CCD
for liquid-solid separation. In the CCD circuits, solids and
washing solutions move countercurrently to each other in
thickeners to achieve displacement of all but 1 percent or less
of the soluble values from the solid residue. The residue is
then discharged to waste while the solution advances to
purification and concentration.
At some mills, the sands are separated from the slimes by
cyclones and/or mechanical classifiers. Usually, this is done to
prevent the coarse sand particles .from overloading the
thickeners. After the sand-slime split is accomplished, the
slime pulp will contain over 99 percent of the soluble uranium,
and the sands can therefore be discarded. The slime fraction can
then be processed in a conventional CCD thickener circuit. At
two mills, however, the slimes are treated in RIP .circuits to
recover uranium directly from the pulp. Solution from the CCD
circuit is clarified or filtered to insure removal of fine,
suspended solids from the uranium-bearing liquor.
Concentration
The next step involves concentration of the uranium in solution.
All acid leaching mills use at least one stage of resin ion
exchange (IX) or solvent extraction (SX) and in some cases both
to selectively extract uranium from the leaching solution.
Subsequent removal of uranium from the resin or solvent with a
suitable reagent yields a purified and concentrated solution of
uranium from which a high-grade uranium product can be
3-24
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precipitated. Solvent extraction and resin ion exchange both
involve the interchange of ions between the leaching solution and
either a solid resin or an organic liquid. Both techniques are
multistage processes employing various types of equipment to
contact the solution with the exchange media.
Resin ion exchange involves contacting the solid 20—50 mesh resin
beads with uranium-bearing liquor in a series, of tanks or
"columns." The uranium ions are selectively adsorbed onto the
resin beads and the barren solution leaving the columns can be
recycled to the CCD washing circuit and/or discarded. After the
resin beads are saturated with uranium, the resin is eluted with
a suitable reagent, and the concentrated solution is pumped to
the precipitation circuit.
RIP systems are used to recover dissolved uranium directly from
slime pulp. Different types of specialized equipment and
circuits are used for this purpose in which, as the name implies,
the resin is suspended directly in the pulp.
The solvent extraction process involves transfer of the uranium
ions in the solution to a liquid organic extractant. The organic
complex formed with uranium is soluble in the organic phase and
insoluble in the aqueous phase. The exchange reaction requires
intimate mixing of the two phases. Subsequent separation of
these immiscible phases by settling yields a top layer of the
metal-enriched organic solution and a bottom layer of barren
solution which is recycled to the CCD washing circuit and/cr
discarded. The loaded organic is then recontacted .with a
3-25
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suitable reagent to transfer the uranium back to a concentrated
aqueous solution.
A two-stage concentration process employing resin ion exchange
followed by solvent extraction is termed the Eluex process.
Conventional column or RIP ion exchange is used to adsorb soluble
uranium. The loaded resin is eluted with sulfuric acid, and the
eluate is fed to a solvent extraction circuit where uranium is
extracted by an organic liquid. The loaded organic is stripped
of the uranium, and the concentrated solution goes to
precipitation. The Eluex process is an extremely efficient
method for concentrating uranium from dilute solutions and
eliminates extraneous ions (such as chlorides used during elution
and stripping) from the circuit (Merritt, Oct. 1977) . Also, the
process decreases reagent costs and may provide a purer uranium
product. The system, however, is more complicated than other
concentration processes and usually requires a greater capital
investment. Although the exchange resins and organics are very
selective for uranium, certain impurities may interfere with IX
or SX and complicate the entire concentration circuit.
Precipitation
Several ' techniques can be used to precipitate uranium from acid
solutions; direct neutralization with a base such as ammonia is
the most common. The uranium precipitate (yellowcake) is
dewatered, dried and shipped to the refinery. This final product
usually contains 85 percent to 95 percent U3O8 and a very small
percentage of uranium daughters.
3-26
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Strong Acid Curing
Acid leaching methods other than mechanical or air agitation have
been used in the U.S. and are now used at certain foreign
operations. One such method is the strong acid curing technique.
This process involves agglomerating coarsely ground ore with
concentrated sulfuric acid and allowing the wetted but free-
flowing ore to cure at elevated temperatures in silos, rotating
drums or on p'ads. The acid-cured material is water leached, and
the dissolved uranium can be recovered by the various methods
previously described. Proponents of the process claim reduced
acid consumption, increased extraction, decreased reaction times
and lower capital costs (Lendrum, 1974; Smith ana Garrett, 1972).
33.2
Conventional Alkaline Leaching
Unlike acid leaching systems, alkaline- leaching requires the use
of an integrated, closed-circuit process, since economics dictate
recovery of the reagents in the leaching solutions.
A typical alkaline leaching flowsheet is illustrated on
Figure .3—7.
Crushing and Grinding
The crushing plant for alkaline circuits is essentially the same
as an acid-leaching plant except for the grinding circuit. In
the alkaline-leaching process, the chemical reactions are slower
and must be assisted by exposing more of the mineral surfaces.
To obtain the finely-ground product, the . grinding-sizing
operation is usually performed at relatively low pulp densities;
3-27
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Ore from Receiving Pads
Primary Crushing
Secondary Crushing
Grinding &
Classi fication
solution
Clarification
Recarbonation
Liquid- Sol id
Separation
solution
Leaching
Liquid-Sol id
Separation
residue
TAILINGS POND
Precipi tation
Dewatering
SOURCE: CSMRI
Drying &
Packaging
YELLOW CAKE
(U308)
Figure 3-7
UsOs Extraction by Alkaline Leaching
3-28
-------
therefore, a thickener or filter is used between the grinding and
leaching circuits to remove the excess solution. The excess
solution is recycled to the grinding circuit, and the thickened
pulp (50—60 percent solids) is transferred to the leaching
circuit.
Leaching
Both atmospheric and pressure leaching vessels are used in
alkaline circuits, and leaching times are related to the
temperature and pressure used. Pressure leaching in autoclaves
may require from 4 to 20 hours at temperatures ranging from
95 to 120 degrees Centigrade and pressures varying from
30 to 90 psig. Air—agitated Pachucas are frequently used for
atmospheric leaching at temperatures of 75 to 90 degrees
Centigrade and leaching times of up to 96 hours. Pachucas are
particularly well-suited to alkaline leaching, since the
agitation air also provides the air necessary to oxidize the
uranium. Since most Pachuca tanks are 40 to 60 feet deep, the
benefit of approximately 25 psig at the bottom of the tanks is
also realized.
Liquid-Solid Separation
The method of separating the liquids from the solids in an
alkaline circuit is very similar to that used in an acid system
except that filters are generally preferred because of tetter
washing efficiency and because of the difficulties associated
with achieving good densification with the finer solids and more
viscous alkaline solutions.
3-29
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Precipitation
Since alkaline-leaching solutions are very selective for .uranium,
the uranium can be precipitated directly from the clarified leach
liquor, and thus the - concentration step prevalent in acid
leaching circuits can be eliminated. Two methods are used to
precipitate uranium from alkaline liquors. If nearly
quantitative recovery is required, the solutions are acidified,
boiled to expel carbon dioxide and then neutralized to
precipitate the uranium. However, it is usually more important
to conserve the reagent for recycle than to achieve complete
precipitation, and therefore the preferred method is to
precipitate yellowcake with sodium hydroxide. The precipitate is
dewatered, dried, packaged and shipped to the refinery (Merritt,
April 1977). .
The solution from the precipitation circuit is regenerated and
recycled;, The regeneration step involves sparging the solution
with carbon dioxide in recarbonation towers to achieve the
desired carbonate content. Solid sodium carbonate may also be
added depending on the sodium balance throughout the circuit.
3.3.3
In-Situ Leaching (Solution Mining)
In—situ leaching is a relatively new method of extracting uranium
in which wells are injected with a lixiviant and the uranium-
bearing liquor is recovered. The uranium is recovered by
drilling into the ore body, circulating a lixiviant to dissolve
the mineral, extracting the values from the liquor and
3-30
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regenerating the lixiviant for continued use underground (Lewis,
et al., 1976).
Advantages and Disadvantages
Increasing interest in this technique is understandable since
solution mining offers several advantages compared to
conventional mine-mill complexes. For ore bodies mineable by
in—situ leaching, the advantages include:
• Minimal surface disturbance, particularly compared to
surface mining
• Personnel exposure to radiation is significantly reduced
• Lower grade ores can be treated, effectively increasing
the recoverable reserves of uranium
• Lower capital costs, improved cash flow, and generally
greater return on the investment
• Less waste generation and land restoration
Major disadvantages are the potential for ground water
contamination and a lower level of uranium extraction. Also,
few ore bodies are suitable for in—situ leaching.
3-31
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Solution Mining Criteria
For an ore body to qualify as a candidate for solution mining,
the following criteria must be met (Hancock, 1977):
The deposit should be a relatively horizontal bed
underlain by impermeable strata.
The ore body must be below the water table (i.e., a
uraniferous aquifer) .
The permeability, porosity and hydrology of the deposit
must be favorable.
Well Field Operations
Well development is perhaps the most important aspect of solution
mining. Wells for injecting the leaching solution are typically
4 inches in diameter and cased with PVC pipe cemented to the
surface. Production wells are similar in construction but are
usually larger in diameter. The continuous casing is interrupted
where the well intersects the mineralized zone to allow
introduction of a lixiviant. An example of well construction and
a vertical cross section of a typical well field is shown on
Figure 3—8 (Wyoming Mineral Corp., 1976). Several different
types of well patterns have been investigated, but the five-spot
pattern is probably the most common. A typical five-spot pattern
used at U.S. Steel's property at Clay West, Texas, is shown on
Figure 3-9 (White, 1975).
3-32
-------
Well Head
PCV Casing—gii
i-vViii--Screen Casing
SOURCE: Wyoming Mineral
Corporation
Upper
Sandstone^
Uni.t
Recovery Wei I
Injection We!
Recovery Wei I
Ground Level
Uranium Ore
—^-*
-^__
Well Screen
Shale or Mudstone
(Confining Layer)
Figure 3-8
Well and Well-Field Design for Solution Mining
Sandstone
Aqu i fer
3-33
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A
A A
A
Outline of Pattern
A
Wei
/
) / f
s
k
;
100ft
A
f
l
J^-—
X"
A
~ Shallow Monitor Wells
&
^>\
A
A
Injectors are Located at each Grid
Intersection
Producers are Located at Each Grid Center
A
SEE DETAIL BELOW
Injection Wei I
Injection Wei I
Figure 3-9
Typical Well-Field Pattern
A
SOURCE: Wyoming Mineral
Corporation & Hancock, 1977
njection Wei
Recovery Wei
njection Wei
3-34
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Injection of a lixiviant forms a hydraulic gradient, within the
uraniferous aquifer. This gradient, together with the withdrawal
rate at the production well, determines the direction and
velocity of solution flow; Solution flow is toward the
production well, since the hydraulic head at that point is less
than that developed at the point of injection. Thus, the pumping
rates and pressures can be used to confine the lixiviant to the
desired area; Normally, more liquor is withdrawn than injected
to prevent solution migration and contamination of the ground
water. Monitor wells are placed in the aquifer as well as
outside the ore zone to detect escaping solution. If solution
migration is noted, the hydraulic gradient can be adjusted by
pumping to force the liquor back into the well fiald.
The uranium-bearing liquor is collected from the recovery wells
and pumped to the plant area. The liquor is usually clarified
and then treated in ion exchange columns to remove the uranium.
A typical flowsheet for a solution mining operation is shown on
Figure 3—10.
Although several types of leaching solutions can be used to
extract the uranium, relatively weak solutions of ammonium
bicarbonate or carbonate are used at most operations. Unlike
conventional milling, the choice of reagent for in—situ leaching
is based primarily on underground performance, including factors
such as selectivity, maintenance of permeability, suitability to
recirculation and environmental considerations.
3-35
-------
Leach Field
Restoration
Leach Field
H >
I
i barren
i solution
L,
1
Solution
Treatment
pregnant solution
Resin Ion
Exchange
REAGENTS
NH3, C02
OXIDANT
recycle
leaching evaporation
solutions
water
Holding
Ponds
|
Solution
Purification
— --- 4
disposal
I 1
i
Precipitation
REAGENTS,
STEAM
Dewatering
Dry i ng i
Packaging
YELLOW CAKE
PRODUCT
SOURCE: CSMRI
Figure 3-10
UsOs Extraction by Solution Mining
3-36
-------
3.3.4
Heap Leaching
Heap leaching is broadly defined as laaching of an ore in a
static or semistatic condition either by gravity flow downward
through an open pile or by flooding a confined ore pile. Heap
leaching is useful for the treatment of low-grade dumps, small
ore bodies located at considerable distances from the processing
facilities, ores that otherwise would have been treated as waste
material or, in some cases, abandoned mill tailings. The major
disadvantage of heap leaching is that uranium recovery is lower
than for conventional milling processes. Not all of the ore in
the sloping sides of the heap is contacted by the leaching
solution, and therefore uranium in the unwetted zone is not
recovered.
Heap Leach Pad Construction
Typically, leaching pads are prepared by leveling a site and
covering it with an impermeable liner such as plastic sheeting or
a clay base (Woolery et al., 1977). The pad is constructed with
a slight slope, and pipes are placed at intervals to collect the
solution. The entire pad is then covered with gravel to improve
drainage, and the ore is placed on the pad and leveled. Usually,
berms are constructed around the ore pile to permit ponding of
the leaching solutions. The actual size and configuration of a
heap may vary, but a typical construction for heap leaching is
illustrated on Figure 3—11 (Merritt, 1971). The solution flows
downward through the ore, into the pipes, and is collected in
launders. Weak sulfuric acid solutions are used, and several
3-37
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Acid from Leach
Make-up Tank
Collection Trough
SOURCE: Merritt, 1971
Figure 3-11
Typical Construction for Heap Leaching
Retaining Ridges to
Form Acid Ponds
Waste rock
Fine Gravel Cover
Polyethylene Sheet or Clay Base
Prepared Ground Site
Perforated Col lection Pipe
To Solution Sump
-------
months may be required to complete the leaching cycle.
Uranium Recovery Options
Uranium can be recovered from the solution by the methods
previously discussed—IX, SX, or Eluex. At Western Nuclear's
heap leaching operation in Wyoming, which is not operating at
this time, high-grade solution was shipped to the nearby mill for
uranium recovery while low-grade solutions were processed through
a small SX circuit at the site. Yellowcake was precipitated at
the site but transported to the mill for subsequent drying and
packaging. At Union Carbide's heap leaching operation at
Maybell, Colorado, the uranium is concentrated by IX and
precipitated at the site, but the yellowcake product is shipped
to Union Carbide's Uravan, Colorado, plant for further
processing. Ranchers Exploration and Development Company
recently initiated a heap leaching operation near Naturita,
Colorado. The operation is unique in that previously abandoned
uranium mill tailings are being reprocessed. In this case, the
tailings are being moved for processing from a river flood plain
to a more desirable disposal site.
As with solution mining, the costly grinding and liquid-solid
separation steps associated with conventional milling are
eliminated. However, the ore must be mined and usually must be
crushed to some extent and stockpiled to facilitate leaching.
Leaching in heaps or in—situ requires several months for maximum
uranium extraction in contrast to leaching times of a few hours
in the majority of conventional mills. Also, recovery from a
3-39
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heap or solution mining operation rarely exceeds
60 to 70 percent, while recoveries in excess of 90 percent are
common at conventional mills. No one processing method is right
for a particular ore body—each case must be treated separately
and a method selected based on the characteristics of the ore and
the process economics.
Byproducts
The description of the various processing methods was simplified
somewhat in that certain impurities in the uranium ore can
complicate the milling flowsheet, as will the recovery of
byproducts. Vanadium, copper and molybdenum are notable
byproducts of uranium mills.
3.3.5
Other Methods
Most of the uranium concentrates produced in the U.S. each year
are processed by the methods described. Treatment of other types
of ores, however, often yields uranium as a byproduct. Phosphate
and copper ores are notable examples. These ores and resultant
waste streams may require consideration as radioactive materials.
Uranium Byproduct of Phosphate Concentrate
It has been estimated that the minable reserves of phosphate rock
in the U.S. contain more than one billion pounds of uranium.
Since the uranium content of the phosphate rock is 50 to 200 ppm,
conventional leaching methods have not been effective in
selectively extracting the uranium. However, an increasing
amount of phosphate concentrates are being converted to
3-40
-------
phosphoric acid, and sulfuric acid used to digest the phosphate
concentrates also dissolves any contained uranium. A number of
uranium recovery methods are being studied. The most successful
method developed thus far is a complex solvent extraction
technique for recovering the dissolved uranium from the impure
phosphoric acid. Uranium Recovery Corporation has been operating
a commerical facility near Bartow, Florida, for several years,
and Gardinier Incorporated is proceeding with construction of a
similar plant near Tampa. Other companies with processes in
various stages of development include Earth Sciences,
Incorporated, Gulf Oil Chemicals, and Preeport Minerals (Ross,
1975) .
Uranium Byproduct of Copper Leaching
Heap leaching of copper ores is practiced throughout the western
United States. In this process U308/ if present, is also
extracted, and leach liquors at many operations contain from
1 to 40 ppm U30a. Resin ion exchange can be used to recover the
uranium. At the present time, Wyoming Mineral Corporation's
Eluex plant at Kennecott's Bingham Canyon property is the only
commercial facility extracting U30a from copper leaching
solutions. Anamax is operating a similar pilot plant at their
copper mine south of Tucson, and several other companies are
evaluating this source of uranium (Brooke, 1976).
3.3.6
Processing Methods at U.S. Uranium Mills
The mining and processing methods used at domestic uranium mills
are outlined in Table 3—2A. Proposed facilities have been listed
3-41
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Plant
Anaconda Co., Grants, New Mexico
Atlaa Corp., Moab, Utah
Conoco l> Pioneer Nuclear, Falls City, Texas
Cotter Corp., Canon City, Colorado
Dawn Mining Co. , Ford, Washington
Exxon, U.S.A., Powder River Basin, Wyoming
Federal American Partners, Gas Hills, Wyoming
Intercontinental Energy Corp. , Pawnee, Texas
Kerr McGee Nuclear Corp., Grants, New Mexico
Lucky Me Uranium Corp. , Gas Hills, Wyoming
Lucky Me Uranium Corp., Shirley Basin, Wyoming
Mobil Oil Co.. Brunt, Texas
Rio Algom Corp., La Sal, Utah
Rocky Mountain Energy, Powder River Basin, Wyoming
Ranchers Exploration, Naturita, Colorado
Sohlo- Reserve, Ccbolleta, New Mexico
Union Carbide Corp. , Uravan, Colorado
Union Carbide Corp., Gas Hills, Wyoming
Union Carbide Corp. , Maybcll, Colorado
Union Carbide Corp. , Klngsvlllc, Texas
United Nuclear Corp., Church Rock, New Mexico
United Nuclear - Home stake Partners, Grants, New Mexico
U.S. Steel, George West, Texas
U.S. Steel - Niagra Mohawk, George West, Texas
Uranium Recovery Corp., Mulberry, Florida
Western Nuclear, Inc., Jeffrey City, Wyoming
Wyoming Mineral Corp., Brunl, Texas
Wyoming Mineral Corp., Ray Point, Texas
Wyoming Mineral Corp. , Blngham Canyon, Utah
Mining
Method
Operational
O.P. t U.G.
U.G.
U.G.
O.P.
U.G.
O.P.
O.P. + U.G.
U.G. + O.P.
In Situ
U.G.
O.P.
O.P.
In Situ
U.G.
O.P.
Nono
U.G. + O.P.
U.G.
O.P.
O.P.
O.P.
In Situ
U.G.
U.G.
In Situ
In Situ
None
U.G.
In Situ
In Situ
None
Leaching
Method
Acid
Acid
Alkaline (Na)
Acid
Alkaline (Na)
Acld-Preasure
Acid
Acid
Acid
Alkaline (Nil,)
Acid
Acid
Acid
Alkaline (NH,)
Alkaline (Na)
Acid
Acid Heap Cure
Acid
Acid
Acid
Acid Heap
Acid Heap
Alkaline (Nil,)
Acid
Alkaline (Na)
Alkaline (NH,)
Alkaline (NH,)
None
Acid
Alkaline (Nil,)
Alkaline (NH,)
None
Liquid-Solid
Separation
CCD
CCD + Flit.
Filt.
CCD
CCD + Flit.
CCD
CCD
CCD
SS
None
SS
CCD
SS
None
Filt.
CCD
None
CCD
CCD
S3
None
None
Nono
CCD
Flit.
None
None
None
SS
None
None
None
Concentration
SX
SX
None
SX
None
SX
IX
SX
RIP 4 SX
IX
SX
Eluex
SX
IX
None
SX
SX
SX
IX
RIP + SX
Solution to
IX
IX
SX
None
IX
IX
Precipitation
NH,
H,0,
NaOH-HjO,
NH,
NaOH
NH,
NH,
NH,
NH,
Steam
NH,
NH,
NH,
Steam
NaOH
NH,
NH,
NH,
NH,
NH,
Main Mill---
--
--
NH,
NaOH
--
--
SX from Phosphoric ---
RIP + SX
IX
IX
-- Eluex from
NH,
--
--
Cu Solutions--
SOURCE) CSMRI
Key to Table: O.P. - Open Pie
Table 3-2A
Process Variations at Operational U.S. Uranium Mines and Mills
U.C. • Underground
CCD • Councercurrenc Decancation In Thickeners
SS - Sand Slime Separation
File.- Filter*
IX - Column Ion Exchange
SX - Solvent Extraction
RIP • Realn In Pulp
-------
in Tails 3—2B and are in various stages of development (White,
1975; Facer, 1977; Reed et al., 1976).
3.3.7
Future Trenas in Yellowcake Production
In 1975, 23 open—pit mines produced 55 percent of the uranium ore
while approximately 42 percent of the tonnage came from
121 underground mines. The balance of production was attributed
to heap leaching operations, solution mining, uranium recovered
from mine waters and phosphoric acid, and miscellaneous low—grade
stockpiles. In 1974, the percentage of ore mined from open pits
was 58 percent and 40 percent from underground mines (Prast,
1976; Gordon, 1976). However, it is difficult to predict trends
with any reasonable degree of accuracy. New discoveries in rlaw
Mexico are deep and will therefore be exploited by underground
mining methods. In contrast, several large, shallow, low—grade
deposits are being investigated elsewhere, and economic
development of these ore bodies will require mining large
tonnages from open pits.
New plants are not likely to differ significantly from existing
plants. Recent improvements in filtration, ion exchange, and
thickening technology will alter the type of equipment used, but
the basic processing methods will remain the same. However,
exploitation of small, low-grade deposits by solution mining, and
heap or vat leaching will receive increased attention. Portable
skid—mounted plants may be used in many cases or crude
concentrates and solutions may be shipped to mills located some
distance away from the field operation. Also, beneficiation
3-43
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Plant
Chevron Oil, Panna Maria, Texas
Cleveland Cliffs Iron Co.. Pumpkin Duties, Wyoming
Conoco, Crownpolnt. Now Moxlco
Energy Fuels, Ulanding, Utah
Gulf Mineral n.'sunrren. McKlnlry County, New Mexico
Homestake Mining Co., Gunnison, Colorado
Mobil Oil Co., Crownpolnt, Now Mexico
Ogle Petroleum, Bison Basin, Wyoming
Petrotumlc 3, Shirley Haaln, Wyoming
Phllllpps Petroleum, McKinloy County, New Mexico
Plouec r- Uravan, Uravan, Colorado
Plateau Resources. Ltd.. Hanks vlllo, Utah
Rocky Mountain Energy. Casper. Wyoming
TVA. Edgemont, South Dakota
Union Oil. Shirley Rasin, Wyoming
United Nuclear Corp.. Morton Ranch, Wyoming
Wyoming Minerals Corp., Irigrary Situ, Wyoming
Gardinler Inc. . Tampa. Florida
Cyprus Mines Corp.. Canon City, Colorado
Freeport Minerals, Uncle Sam, Louiaianna
Texura Corp. , llobson. Texas
Solution Engineering. Three Rivers. Texas
Phelps Dodge, ttishee, Arizona
Anamax, Tucson, Arizona
Kerr McGee Nuclear Corp., Casper, Wyoming
Mining
Method
Proposed
O.P.
In Situ
U.O.
Ore Buying
U.G.
O.P.
U.G.
In Situ
O.P.
U.G.
U G
U.G. + O.P.
U.G.
In Situ
O. P.
O.P.
U.G. + O.P.
Op
. i .
In Situ
None
O.P. + U.G.
None
In Situ
Recovery from Tailings
None
None
O.P. + U.G.
Leaching
Method
Acid
Alkaline (Nil,)
Acid
Acid
Alkaline (Na)
Acid
Alkaline (NH,)
Acid
Acid
Acid
Acid
Acid
Acid
Acid
Acid
A rlfl
i. 1U
Alkaline (Nil,)
None
Acid
No no
Alkaline (NH,)
Liquor
None
None
--
Liquid- Solid
Separation
Nona
SS or CCO
1 1
CCD
Fill.
ecu
None
CCD
CCD
Un * rtfif
Concentration Precipitation
IX Steam
SX NH,
.
SX NH,
None NuOH
SX NH,
DC Steam
SX NH,
SX NH,
.... Unannounced
CCD
None
CCD
CCD
f f n
v> *** if
None
None
None
None
None
None
SX NH,
IX
II c&d
SX NH,
SX NH,
cy KJI i
3 A r« 1 1)
IX
SX from Phosphoric
- Unannounced
SX from Phosphoric
IX
-- Klu ex from Cu Solutlona--
-- Elucx from Cu Solutlons--
- Unannounced .
SOURCE: CSHRI
Key co Table: O.P. *> Open Pit
U.C. *> Underground
CCD - Councercurrenc Decancatlon la Thickeners
SS ' Sand Slime Separation
File.- Filters
IX "• Column Ion Exchange
SX * Solvent Extraction
RIP « Resin In Pulp
Table 3-20
Process Variations Proposed for Future U.S. Uranium Mines and Mills
-------
methods and ore buying stations may increase. Experience has
shown that some ore buying stations may also become mill sites
when sufficient ore supplies are assured through exploration and
mining in nearby areas.
Beneficiation
For the few ores exhibiting suitable berief iciation
characteristics, effective methods have included sizing,
radioactive sorting and froth flotation to generate uranium—rich
concentrates. However, beneficiation methods rarely yield
tailings low enough in uranium to justify the economic loss as
compared to processing all of the ore in a mill. The most
successful applications of beneficiation techniques have not been
for direct concentration of the uranium, but for separation of
the ore into fractions, such as high and low lime and carbon or
sulfide fractions, which can be treated more efficiently by
specific leaching methods. Nevertheless, beneficiation methods
will receive increased attention as lower and lower grade ores
are developed.
Ore Buying Stations
Certain corporations buy ore from several independent miners in a
given area. The individual lots of ore are processed through a
centrally located sampling plant to determine the uranium content
of the ore lot and expedite settlement payments. The primary
crushing is accomplished at the sampling plant, and the crushed
ore is then shipped to the mill, which may be located some
3-45
-------
distance from the sampling plant. Examples of ore buying
stations include the four sampling plants located at Blanding,
and Hanksville, Utah (operated by Energy Fuels and Plateau
Resources, Ltd.) and two plants located near Naturita and
Whitewater, Colorado (General Electric Corp. and Cotter Corp.).
3.4
Production Costs
Uranium production costs vary substantially with the location of
the deposit, stripping ratios, ore grade, mill capacity, reagent
consumption and many other factors. Resource requirements and
capital and operating costs for a mine/mill complex are presented
in the following section.
3.4.1
Resource Requirements
In addition to the availability of an ore supply, important
considerations in evaluating a potential site for a uranium mill
are the availability of labor, utilities, land, services and
sources of required supplies in the area. Significant resource
requirements for uranium complexes are:
• UU30R - Total employment in the uranium industry in 1975
was approximately 9,700, 2,100 in exploration, 5,400 in
mining and 2,200 in milling. Of the 5,400 individuals
associated with mining, 1,800 were employed as underground
miners, 700 as open— pit miners and 1,200 as supervisors
and administrators.
A typical 2,000 tpd open— pit conventional acid— leaching
operation (CCD, SX NH3 precipitation) employs
approximately 200 people. Of the 200, approximately
65 would be employed in the mill, 90—100 in the mine and
the remainder in administration and nonprocess functions.
However, labor requirements vary greatly and may be as
high as 400—450 people (Goodier, 1978) . A total of about
3-46
-------
230 people would be employed during the peak construction
phase of such a facility. For comparison, a typical 1,000
tpd underground mine would require approximately the same
labor force for mining as a 2,000 tpd open— pit operation.
UTILITIES - Requirements for utilities vary substantially
in the industry, but the range for uranium mills is
approximately (Merritt 1971) :
Utility Quantity/Ton ; Or e
Electricity 17 to 35 kw hr
Fuel 348,000 to 1,120,000 Btu
Water 1 to 7 tons
Steam 179, to 800 Ibs
Compressed Air 1,000 to 13,000
Most of the power required by uranium mills is for
crushing and grinding, and the wide range is due to
variations in ore hardness and fineness of grind required.
Variations in fuel requirements are due to different
temperatures employed during leaching, the amount of
building heat required, and the availability of by— product
steam from various sources such as acid plants. Most of
the variations in water and air requirements are due to
the process employed.
Utility requirements for mines also vary substantially.
Power requirements for a 1,000 tpd underground mine were
recently reported at approximately 22 kw hr/ton. Of this
value, 50 percent was for ventilation. Water consumption
at the same mine was reported at 1,000 gpd (Harvsy 1977).
Utility requirements for open— pit mines are considerably
different than those for underground mines. Electrical
power requirements are minimal, 2 kw hr per ton of ore;
principal applications are pit dewatering and lighting.
Water requirements are normally greater in open— pit mines
with dust abatement the major use. Consumption could
approach 50,000 gpd, although much of this could be
obtained from the pit itself. Fuel consumption for mobile
machinery represents the major utility requirement in
surface mining. Fuel consumption typically runs from
10 to 40 gal of diesel fuel per machine per hour (Goodier,
1978). Mines using electric-powered equipment would
consume more electricity and less fuel. Depending on
quantities of overburden moved to recover the ore, fuel
requirements could range from 2 gal per ton.
SUPPLIES - A large portion of the supplies necessary to
sustain an operation are the chemicals used in the milling
operation. It is not possible to generalize chemical
requirements, since the amounts will vary widely with the
type and amount of ore being processed. Acid requirements
3-47
-------
SUPPLIES, Continued
can vary from 40 Ib/ton for an easily treated Wyoming ore
and 300—500 Ib/ton for a refractory ore from the western
slope of Colorado, For alkaline circuits, sodium
carbonate consumption can vary from 10 to 80 Ib/ton of
ore.. Similary, oxidant requirements for an acid circuit
can vary from 0 to 40 Ib of sodium chlorate per ton of ore
treated. Flocculating agents are used to aid the
liquid—solid separation process. Typical requirements are
0.1 Ib/ton of ore. Ammonia requirements for yellowcake
precipitation are typically 0.4 Ib/lb of U30a. Other
chemicals which are used in a typical acid circuit include
lime, kerosene and amine organic extractant. Blasting
explosives also contribute significantly to supply
requirements.
• LAND - Surface land requirements are directly related to
the type of mining method used and the tonnage of ore
processed. A 5,000 tpd open—pit operation with a 30:1
stripping ratio will cover more surface area than a
1,000 tpd underground operation. The mine is the greatest
land consumer, followed by the tailings pond, and then the
surface works. Several thousand acres may be involved in
a surface mining operation, and the workings of an
underground mine can cover as much area, although it is
not visible. Typical land requirements for the mill and
other surface works range from 10 to 20 acres.
• MAJOR MINE EQUIPMENT.- Machinery requirements for a
1,000 tpd underground and open—pit mine are compared
below:
Underground Open-pit
14 long hole drills 3 shovels, 16 yd3 electric
3 Wagner trucks 2 rotary blast hole drills
11 tractor-trailer units 2 hydraulic backhoes, 3 yd3
1 single-boom jumbo 16 haulage trucks, 120 ton
1 road grader 9 haulage trucks, 35 ton
1 compressor 2,400 cfm 2 wheel loaders
1 compressor 1,200 cfm 7 push-pull scrapers
1 fan 4 crawler tractors
1 hoist 2 wheel tractors
3 motor graders
The equpiment fleet for the open—pit operation includes
the equipment needed for pre-production stripping.
• SUPPORT FACILITIES - In addition to the mine, the mill and
the tailings pond, additional on—site facilities are
required to service the operation. Support facilities
V J
3-48
-------
which are common to all processing complexes include a
warehouse, a mill maintenance shop, a repair and service
garage for the mine motile equipment, an analytical and
metallurgical laboratory, a changehouse and an
administration building. Smaller, additional buildings
are required for the scale house, fire truck garage,
lubrication oil storage, flammable liquids storage,
tailings water pumphouse, and tire storage.
Other on— site and off— site facilities may be necessary to
support the operation. Facilities which may be included
in this category include an acid plant and a town site.
Western Nuclear 's operation at Jeffery City, Wyoming,
represents a good example of an .uranium operation with a
town site.
3.4.2
Capital and Operating Costs
Although the price of U30a for immediate delivery has risen from
35.95/lb in August 1971 to greater than S40/lb today (Nucleonics
Week, March 16, 1978), the average contract price for U3Oa is
approximately $14/lb. Since many uranium producers have been in
operation since the early 1950' s, the plants and all of or a
major portion of the mine development costs have been amortized.
For these reasons, these producers can continue to produce
relatively low— cost yellowcake.
In contrast, the newcomer to the industry must absorb the
inflation which has occurred since the 1950 's and must,
therefore, demand a higher price for the product. Since 1973,
average mining labor costs have increased from approximately
$4.50/hr to S8/hr. The cost of drilling rigs capable of
1,000— foot depths has increased from $22/hr in 1970 to about
$65/hr in 1978 (Butts, 1978) . Also, the cost of No. 2 diesel
fuel has risen over 350 percent in the past six years (Koch,
3-49
-------
1977). These are but a few examples of the inflationary trends
affecting the industry. For these and other reasons, a new
producer in 1978 must receive $25 to $30/lb of D308 to break even
(recover capital and operating costs). This break—even value
excludes the cost of exploring for new reserves.
Due to the many possible combinations of mining and processing
methods, it is difficult to present cost generalizations.
However the capital expenditure required to develop a
1,000—foot—deep ore body by underground mining methods is roughly
$80 to $120 (1978 dollars) per annual ton of ore recovered. A
2,000—foot—deep deposit could require capital investment of as
much as $200 per annual ton. The capital cost of a surface mine
can equal the capital costs of the underground mine. This
situation is due to the extensive pre-production stripping
required to expose the ore body. Mill capital costs are
presently about $15,000 per daily ton of capacity (1978 dollars),
assuming a conventional acid—leaching, CCD and SX circuit is
utilized.
Example Costs for Open—pit Mine and Mill
Typical capital and operating costs for a new conventional 1,000
tpd open-pit mine and mill facility are summarized in Table 3—3
(Phillips, 1977). The costs are based on milling 1,000 tpd of
ore containing 0.10 percent U308 with a stripping ratio of
22 cu yd/pound of U308. Truck shovel combinations and scrapers
are used for stripping, and one—third of the stripping costs are
treated as pre—stripping. Trucks and front end loaders or
3-50
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Operating Costs
Strip and Internal Waste
Mining
Milling
General and Administrative
Aquifer Restoration
Royalty and Severance Taxes
Total
$/ton Ore
20.00
3.80
7.00
3.00
0.80
3.60
$38.20
$/lb U 0
3 8
11.11
2.11
3.89
1.67
0.44
2.00
$21.22
Investment $ Million
Mine Mobile Equipment
Mill and Tailings
Mine Shops and Electric
Roads, Site Preparation, etc.
Total Capital
Working Capital
Pre-stripping
Infrastructure
Total Initial Investment
9.0
15.0
2.5
1.0
$27.5
3.0
7.0
4.0
$41.5
SOURCE: Adapted from Phillips, April 1977.
Table 3-3
Economics of Conventional Mining and Milling
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backhoes are used for mining and an internal waste ratio of three
cu yd/ton of ore was assumed. Milling costs were based on a
conventional agitated acid leaching, solvent extraction, .and
precipitation circuit. Acid consumption was assumed at 60 Ib/ton
of ore, and overall recovery was estimated at 90 percent.
General and administrative expenses include on—site supervision,
office and safety personnel, and home office overhead allocation.
Royalties and severance taxes were estimated at 2 percent and
3 percent of gross revenue. Working capital allows for three
e
months of operation, and infrastructure including relocation and
training expenses, housing subsidies and pre—startup
admininstrative expenses. A 24—month construction period was
assumed, and the life of the property was estimated at 12 years.
Estimated Costs for In—Situ Leaching
The estimated capital and operating costs for in—situ leaching of
a 0.05 percent U30a ore body are shown in Table 3-4. The
estimate was based on a production rate of 250,000 Ib U3O8/yr
from a 500—foot—deep deposit. The wells are drilled in a
line—drive pattern, and the number of production and injection
wells are 'egual. The injection and production wells are
constructed identically to allow reversal of functions, and each
well is 5 inches in diameter, cased with PVC and cemented to the
surface.. The wells are spaced at 50 feet, and the injection rate
was assumed at 10 gpm per well. Well costs were increased by
5 percent for failures.
The estimate was based on a sulfuric acid rather than ammonium
3-52
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Operating Costs $/lb U,0
Q
o
Wells - 12 . 10
Pumps and Piping 2.32
Power, Coring, etc. 0.86
Milling 6.76
General and Administrative 1.40
Reclamation 0 . 34
Royalty and Taxes 2. 00
Total $25.78
_ Investment _ ; _ $ Million
Mobile Equipment 2.3
Mill and Tailings 6.5
Roads, Site Preparation, etc. 1.0
Total Capital 9.8
Working Capital 1.4
Initial Well Field 2.2
Infrastructure 1.3
Total Investment $14.7
SOURCE: Adapted from Phillips, 1977.
Table 3-4
Economics of Solution Mining
J
3-53
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carbonate leaching, but the costs should not vary significantly.
Mild stael would replace FRP tanks for a savings, but most other
costs would remain essentially the same. The uranium—bearing
liquor contains approximately 50 ppm U30a .and is processed in ion
exchange columns followed by solvent extraction. Calcined
yellowcake is the final product, overall recovery was estimated
at 60 percent for the solution mining operation. Design and
construction of the in—situ complex was assumed to require
18 months, and the productive life of the deposit was assumed at
12 years to match the open—pit model.
The reported values are presented to acquaint the reader with
general uranium production costs. These cost figures should not
be used to project the economics associated with any existing or
proposed facilities, since estimates vary greatly and depend on
many project specific conditions. For example, the Wyoming
Department of Economic Planning and Development estimates the
operating cost of a uranium mill to be $10 per ton of ore
(Goodier, 1978). . However, certain uranium mill operators have
recently reported that total process chemical costs alone
approach $16 per ton of ore treated (Butts, 1978).
3.5
Mill Tailings Management
Mill tailings, as discussed herein, are defined as gangue and
'other refuse material resulting from the washing, concentration
and treatment of ground ores. Their disposal is a critical part
of the uranium milling, process. In view of the long half lives
of. the radionuclides in tailings, the integrity of related
3-54
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containment structures must be assured for many millennia, which
for planning purposes can be considered perpetuity.
Historically, in the mining industry, some practices have
resulted in unsafe structures, and disastrous failures have
occurred. The problem is complex. An interdisciplinary
technical approach is required for safe and efficient
construction and operation. However, it is possible with today's
earth dam design practices to build safe, permanent structures.
Concerns related to environmental impacts add an additional
dimension to uranium mill tailings management. Post—operational
reclamation and maintenance are important regulatory concerns in
preventing radioactive contamination of the environment and
exposure of the population to radiation.
3.5.1
Performance Objectives
The following performance objectives for management of tailings
from uranium ore processing plants were issued for industry
guidance by the Nuclear Regulatory Commission (NEC Branch
Position, May 13, 1977).
Siting and Design
1 Locate the tailings isolation area remote from people such
that population exposures are reduced to the maximum
extent reasonably achievable.
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r
SITING AND DESIGN, Continued
2 Locate the tailings isolation area such that disruption
and dispersion by natural forces is eliminated or reduced
to the maximum extent reasonably achievable.
3 Design the isolation area such that seepage of toxic
materials into the ground water system is eliminated or
reduced to the maximum extent reasonably achievable.
During Operations
4 Eliminate the blowing of tailings to unrestricted areas
during normal operating conditions.
Post-Reclamation
t
5 Reduce direct gamma radiation from the impoundment area to
essentially background.
6 Reduce the radon emanation rate from the impoundment area
to about twice the emanation rate in the surrounding
environs.
7 Eliminate the need for an ongoing monitoring and
maintenance program following successful reclamation,
8 Provide surety arrangements to ensure that sufficient
funds are available to complete the full reclamation plan.
_ J
3.5.2
Site Selection for Tailings impoundments
Factors which must be considered when evaluating the suitability
of candidate sites for tailings disposal include economics,
engineering feasibility, safety and environmental impact.
Environmental considerations are discussed in Chapter 4.
Site—specific factors are discussed below.
Location of Ore Processing Facility
Suitable locations for tailings disposal have an important
influence on the selection of candidate sites for the ore
3-56
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processing facility. The location of suitable disposal sites
may, in fact, limit siting options. The location of the mill is
also influenced by the mine location and other factors, such as
population centers, transportation and availability of services.
Accordingly, although certain physical conditions are required
for a suitable tailings disposal site, the final selection must
be made in conjunction with economic and engineering studies
which take into account siting of all elements of the mining and
processing facilities.
Topography
A natural depression offers the most economical and, in most
cases, the safest structure for impoundment of tailings, but such
disposal sites are rare. Dams across valleys or on side hills
must take into account storm runoff waters and provide measures
to prevent erosion. A stock—pile type of dam on relatively level
ground can eliminate the damage from runoff water.
Engineering Geology
Thorough geotechnical investigations of a potential site must be
made. subsurface investigations must assess the characteristics
of foundations and abutments with respect to seepage and
stability when subjected to the loadings of the retaining
structures. Geotechnical design parameters for all materials to
be utilized in the retention embankment and its foundation must
be defined. Discussions of necessary geotechnical
3-57
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are presented in NEC Regulatory Guide 3.11, and in Colorado
Geological Survey Guidelines, March 8, 1978.
Seismic Activity
The potential site for tailings impoundment may be subjected to
the effects of seismic activity. Application of modern earth—dam
practices can result in safe impounding structures even in zones
of high seismic activity.
Meteorology
Meteorology is important for site . evaluation. Site
meteorological data and dispersion models are used to estimate
airborne contaminant movement, concentration and radiation dose.
Hydrology
Depending on the methods used to seal an impoundment, the
potential for seepage will vary. Seepage may enter streams,
rivers or potable water supplies through surface runoff or ground
water recharge. Accordingly, the hydrologic characteristics of
the area are important factors in assessing site suitability.
The .requirements for water tightness of the reservoir are thus
related to this hydrologic evaluation.
The - potential for flooding from heavy rainfall and runoff must
also be evaluated to permit impounding structure design that will
avoid overtopping, erosion and subsequent failure. This is
particularly true with cross valley and sidehill types of
embankments which may be in the path of large volumes of storm
3-58
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runoff. Adequate storage volume and diversion channels and
spillways must therefore be used to prevent pollution of
downstream surface waters. The stockpile dam and subgrade
disposal structure are the least susceptible to damage from
excess surface runoff.
Population Density
Population density and future growth projections should be
considered in the'selection of a site for disposal of tailings.
Tailings dams in the proximity of populated areas may be
objectionable for the following reasons:
• Danger of structural failure with resultant release of
pollutants
• Fugitive dust and radioactive emissions during operation
and after decommissioning
• Aesthetic characteristics
« Possible pollution of potable water sources
• Unauthorized removal of tailings
3.5.3
Current Tailings Disposal Practice
In the past, methods of disposing of uranium tailings have
generally followed the methods practiced for waste disposal
from orher mineral processing plants. A uranium tailings
disposal facility, however, has the following unique features:
3-59
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• Hazards from incorrect clam design or facility management
are potentially long—lived because of the long half—life
of the radioactive substances involved.
• Required capacity is generally smaller than for a number
of other mineral processing operations (2,000 tons per day
compared to as much as 100,000 tons per day).
V .J
Disposal and Retention Systems
Historically, the following methods of tailings disposal have
been used:
• Disposal in bodies of water, including rivers, lakes and
oceans. This method is usually inappropriate for uranium
tailings due to the nature of the material.
• Disposal in depleted mines.
• Disp9sal in natural basins.
• Disposal behind embankments constructed of tailings or
borrow material.
Rarely can the activities of mining and milling be coordinated
well enough for the mined—out areas to serve as the only
impoundment site for the tailings. In addition, ground water
pollution potential often makes disposal in depleted mines
unacceptable unless tailings can be dewatered. France and Canada
have implemented such treatment and disposal techniques. In the
United States, however, above-ground disposal has been used.
The predominant method for storage of tailings has been disposal
and retention behind one of the following embankments:
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• CROSS VALLEY — The embankment is constructed in a canyon
or valley. The embankment extends from valley wall to
valley wall.
• SIDE HILL — The embankment is constructed on the side of a
slope. An impounding embankment is constructed on the
downhill side, and the uphill ground surface completes the
enclosure.
• STOCKPILE — A complete embankment enclosure is built on
relatively flat ground.
V
The cross valley method has been the favored method in the past
due to the economics of a single embankment.
Transport and Deposition
Uranium tailings are often transported to the disposal area by
pipeline, since this method provides flexibility in siting the
tailings impoundment. Pipeline transport and methods of
deposition at the embankment are discussed in detail in Aplin and
Argall, (1977).
Tailings Embankment Design and Construction
The purpose of tailings dam construction for uranium mills and
mines is to safely and permanently contain radioactive materials.
Current experience and knowledge in the field of geotechnical
engineering as applied to the design and construction of water
retention dams must be used. With thorough investigation and
planning, economical designs can be produced which ensure safety
and prevent contamination. Where it is not feasible to raise a
tailings dam in stages because of environmental, safety, or
regulatory reasons, construction of a full—height water—retention
3-61
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dam from borrow material or placement of tailings below grade may
be required. •
Three methods of tailings embankment construction have commonly
been used in the mining industry. These include the upstream_
method, the downstream method and the centerline method. Each
method begins with construction of a starter dike.. The
downstream and centerline methods are shown in Figure 3—12.
"Each tailings dam must be developed to meet the specific
requirements of the particular project. Downstream methods of
dam construction should be used for all but very minor dams
located in areas of low seismic activity." (Klohn, 1977).
THE UPSTREAM METHOD - Historically, this is the most
common method because it requires little reworking of the
hydra'ulically deposited tailings. Tailings are discharged
from the crest of a starter .dike. Coarse material settles
out at the dike, with the finer material settling further
upstream toward the pond. Each subsequent dike is shifted
upstream, with its toe resting on top of the previous dike
and its upstream portion over finer material from the
previous lift.
This type of dam is relatively simple and inexpensive, but
it has inherent weaknesses. As the dam height is
increased, the critical failure surface shifts from within
the coarser material at the downstream face to the lower
shear strength finer material and slimes within the dam.
Also, the phreatic surface may rise within the dam as, the
fill height increases. Upstream method impoundments are
particularly susceptible to failure by liquefaction under
seismic loading or to progressive failure due to erosion
or foundation instability. The U.S. Army Corps of
Engineers' position on using "upstream lifting (upstream
method) for the purpose of achieving an impervious barrier
and provide zero discharge for radioactive uranium mill
tailings is that it is not acceptable because structural
integrity can not be assured" (U.S. Army Corps of
Engineers, 1974).
3-62
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TH.£ DOWNSTREAM METHOD - Construction begins with an
impervious starter dam, which may he built as a
homogeneous embankment of impervious borrow material or a
zoned embankment with an upstream impervious zone. In the
case of the homogeneous embankment, an underdrain is
provided to control the phreatic surface (Figure 3—12).
The starter dam is compacted in layers to minimize seepage
and provide a strong structure. The height of the dam is
increased by adding material to the downstream face of the
dam. Material added to the embankment can therefore be
compacted. The centerline of this type of dam shifts
downstream as its height is increased. The impervious
zone of the embankment can be carried into the foundation
by means of a core trench to create an impervious cutoff.
The extent of this core trench depends on the geology cf
the foundation.
The major advantage of embankments constructed by the
downstream method is the the best modern pratice in the
design of earth and rockfill dams can be followed.
Therefore, they can be readily built to withstand
earthquake forces. The major disadvantage of the
downstream method of construction is the large volume of
coarse material required for its construction. If
sufficient environmentally-acceptable coarse tailings are
not available, borrow material may be required. Also,
since the downstream slope changes continuously during
construction, some measures may be required to prevent
wind and rain erosion.
THE CENTERLINE METHOD - A variation of the downstream
method, except that the crest of the dam is raised
vertically without a horizontal shift (Figure 3—12).
Therefore, only the downstream half of the retention
embankment is constructed with the structural integrity
and control which is possible for the whole embankment in
the downstream method. The advantage of this method is
that it reduces the required amounts of borrow materials.
The disadvantage is reduced structural stability.
A summary discussion of tailings dam design and additional
references are presented in Soderburg and Busch (1977), Short
Course, CSU (1978), and NRC Regulatory Guide 3.11.
3-63
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Slurry Pipe Discharging
onto Surface of Pond
Subsequent
Construction
Future
Construction
Engineered Embankment
Starter
Dam
Underdrains
DOWNSTREAM METHOD
Rock Toe FiIter
Final Section
Slimes
Subsequent
Construction
Future
Construction
Irregular Contact
Between SIimes
and Dams
ineered Embankment
Starter
Dam
Underdrains
CENTERLINE METHOD
SOURCE: Adapted from Mittal and Morgenstern, 1977
Rock Toe FiIter
for Final Section
Figure 3-12
Methods of Tailings Dam Construction
-------
Seepage Control for Tailings Embankments
Control of pore water pressure and seepage forces within a water-
retaining embankment is essential to overall embankment and
foundation stability. Measures must therefore be taken to
maintain the phreatic surface at a low level within the
embankment. This is basic to modern earth dam design.
Seepage through the tailings embankment may be reduced to a
minimum by placing an impermeable seal of clay or a membrane on
the upstream face of the dam, or by deposition of tailings slimes.
on the upstream face of the dam. These methods are only
applicable to the downstream method of embankment construction.
In the downstream method, where the whole embankment is
controlled fill, the zoning of the embankment is designed to
provide drainage within the embankment and keep the phreatic
surface low in the downstream zones. Where the embankment is one
homogeneous zone, an underdrain is used to draw down the phreatic
surface (Figure 3—12). In the centerline method, the same
techniques can be applied. However, the full hydrostatic
pressure may be present at the centerline of the embankment. If
a vertical impervious zone is incorporated immediately downs-ream
of the centerline in the constructed portion of the embankment, a
dam equivalent to a conventional dam with an impervious central
core can be provided. In the upstream method, no drainage
provision can be provided, and high phreatic surfaces may result
in many cases. This is one of the factors leading to instability
of this type of structure.
3-65
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In some cases, sand drains or other vertical drains may be
required in the foundation beneath the downstream slope of the
embankment to control pore pressure due to underseepage.in
certain foundation geology.
In conjunction with installation of positive seepage control
measures within the tailings embankment, various monitoring
systems should be installed in the structure. These should
include, as a minimum, the following:
• A system of piezometers in the embankment and foundation
to define the phreatic surface(s) .
• A seepage collection system to monitor volume of flow.
• Wells downstream (i.e. down gradient) of the structure to
facilitate environmental sampling.
Further discussion of seepage control measures are presented in
U.S. Bureau of Reclamation (1973), and Soderburg and Busch
(1977).
Embankment Stabilization
Certain design and construction measures can be taken to
stabilize the impoundment and prevent structural failure. These
measures, listed below, may also assist in the reclamation
program, discussed in more detail in Chapter 4.
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• The potential for erosion of the downstream slope of the
embankment may be reduced by terracing, placing topsoil
and seeding, or placing riprap.
• The potential for saturation and development of excess
pore pressures due to continued precipitation or surface
runoff inflow may be reduced by several means. Shaping
and contouring of the final impoundment surface will
prevent areas of ponding. Placement of a clay seal over
the final surface will minimize infiltration.
• Placement of topsoil and seeding of the finished surface
will enhance the formation of an adequate vegetative cover
and will reduce erosion of the impoundment surface. In
arid climates it may be necessary to substitute coarse
rock to prevent wind and water erosion.
3-67
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CHAPTER 3
References
Aplin, A. C.. and G.O. Argall Jr. Tailing Disposal Today.
Proceedings of the Firs-t International Tailing Symposium, Tucson,
Arizona, 1972.
Brooke, James N. Uranium Recovery from Copper Leaching
Operations. Paper presented at the Mining Convention of the
American Mining Congress, Denver, Colorado, September 26—29,
1976.
Butts, Gary. Projects Manager, Process Manager, Process
Division, CSMRI. Personal Communication, 1978.
Colorado Geological Survey. Guidelines for Preparing Engineering
Geologic Reports for Uranium Mill Siting, Badioactive Tailing
Storage and Associated Land Use Changes, Denver: Colorado
Geological Survey, March 8, 1978.
"Conquista, Conoco—Pioneer U3O3 Venture on Stream." Mining
Engineering, August 1972.
CSMRI. Source Material Furnished under EPA contract
No..68-01-4490.
Dwosh, Douglas M. "Rubber—Tired Versus Rail Haulage as a Service
Function." Mining Congress Journal, January 1978.
Facer, F.J. Uranium Production Trends. Paper presented at the
Uranium Industry Seminar, Grand Junction, Colorado, October
26, 1977.
Fifth Annual Short Course on Embankment Dams Including Mine Waste
Dams. Vol. I and II. St. Louis, Missouri: University of
Missouri of Rolla, August 15—20, 1977.
Gordon, Emanuel. "Uranium—New Projects Anticipate Coming
Demand." Engineering and Mining Journal, March 1976, pp.
190-206.
3-68
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Goodier, John T., Chief of Mineral Development, Wyoming
Department of Economic Planning and Development. Letter to
Mr.'D. Matchett, Stone & Webster Engineering Corporation,
May 2, 1978.
Hancock, Bill. Uranium In—Situ Leaching: Its Advantages,
Practice, Problems, and Computer Simulations. Paper presented at
the annual AOMZ meeting, Atlanta, Georgia, March 1977.
Harvey, G. Jr. Trackless Mining at Union Carbide1s Operations in
Southwestern Colorado and Southeastern Utah. Paper presented at
the Conference on Uranium Mining Technology, University of
Nevada, Reno, Nevada, April 25, 1977.
Hunkin, G. "The Environmental Impact of Solution Mining for
Uranium." Mining Congress Journal, October 1975, pp. 24—27.
Jackson, Dan {Western Editor) "Gulf Eigs in to Tap a Major
Uranium Ore Body". Engineering and Mining Journal, August 1977.
Klohn, Earle J. "Design, Construction, and Performance of
Tailings Dams". Paper presented at the 5th Annual Short Course
on Embankment Dams with Special Workshop Including Mine Waste
Dams. St. Louis, Missouri, August 15—20, 1977. Vo. II.
Koch, Ludwig. Cost Trends. Paper presented at the American
Nuclear Society Conference on Uranium Fuel Supply, Monterey,
California, January 23—26, 1977.
Lendrum, F.C. Developments in Uranium Ore Processing. CIM
Bulletin. Golden, Colorado: Colorado School of Mines,
September 1974.
Lewis, F.M., C.K. Chase, and R.B. Bhappu. Economic Evaluation of_
In—Situ Extraction for Copper, Gold, and Uranium. Paper
presented at the Annual AIME meeting, Denver, Colorado,
September 1976.
Merritt, R.C. Recipe for Yellowcake. Paper presented at the SME
Section Meeting, San Fransico, California, October 10, 1977.
. The Metallurgy of Uranium Extraction. Paper presented
at the Uranium Mining Technology Conference, Reno, Nevada,
April 25-29, 1977.
. The Extractive Metallurgy of Uranium. Golden,
Colorado: Colorado School of ' Mines Research Institute under
contract with the U.S. Atomic Energy Commission, 1971.
Mittal, H.K. and N.R. Morgenstern. Designed Performance—
Tailings. Proceedings of the Conference on Geotechnical Practice
for Disposal of Solid Waste Materials, Ann Arbor, Michigan,
June 13-15, 1977.
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Nuclear Regulatory Commission. Office of Standards and
Development. Regulatory Guide 3.11: Design, Construction, and
Inspection of Embankment Retention . Systems for Uranium Mills
(Revision 1) , March 1977.
. Branch Position: Uranium Mill Tailings Management,
Fuel Processing and Fabrication Branch, May 13, 1977. .
O'Rourke, J. and H.J. Whelan. "The Elements of Practical Plant
Design." Engineering and Mining Journal, June 1968, pp. 160—170.
Phillips, P.E. A Comparison of Open—Pit and In—Situ Leach
Economics. Paper presented at the Conference on Uranium Mining
Technology, Reno, Nevada, April 28, 1977.
Prast, W.G. "Prospects for the U.S. Uranium Industry." Mining
Magazine, October 1976, pp. 349-357.
Reed, A.K..et al. Assessment of Environmental Aspects of Uranium
Mining and Milling. Inter-agency Energy-Environment Research and
Development Program Report. EPA-600/7—76—036, December 1976.
Ross, Richard C. "Uranium Recovery from Phosphoric Acid Nears
Reality as a Commercial Source." Engineering and Mining Journal,
December 1975.
Short Course on Design and Construction of Tailings Dams.
Denver, Colorado: Colorado State University, January 1978.
Smith, S.E.. and K.H. Garrett. "Some Recent Developments in the
Extraction of Uranium from its Ores." The Chemical Engineer,
December 1972.
Soderburg, R. L. and R.A..Busch. "Design Guide for Metal and
Nonmetal Tailings Disposal." U.S. Bureau of Mines Information
Circular 8755. . Washington, D.C.: U.S. Government Printing
Office, 1977.
U.S. Army Corps of Engineers. Letter from Major General J.W.
Morris, U.S..Army Director of Civil Works, to Mr. John A. Green,
Region VIII Administrator, U.S. EPA, October 2, 1974.
U. . S. Bureau of Reclamation. Design of Small Dams. Washington,
D.C.: U.S. Government Printing Office, 1973.
White, Lane. "Wyoming Uranium Miners Set Sight On Higher
Production." Engineering and Mining Journal, December 1975,
pp. 61-71.
• . "In—Situ Leaching Opens New Uranium Reserves in
Texas." Engineering and Mining Journal, July 1975, pp. 73—81.
Wood, J.T. The Anaconda Company: Open Fit Mining of Uranium.
Paper presented at Conference .on Uranium Mining Technology,
University of Nevada, Reno, Nevada, April 25, 1977.
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Woolery, R.G. et al. Heap Leaching of Uranium—A Case History.
Paper presented at the annual AIME Meeting, Atlanta, Georgia,
March 6-10, 1977.
Wyoming Mineral Corporation. "Uranium Solution Mining."
Lakewood, Colorado: Wyoming Mineral Corporation, 1976.
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SITING AND ENVIRONMENTAL IMPACT
CHAPTER 4
-------
CHAPTER 4
Siting and Environmental impact
Once the decision has been made to proceed with a uranium mining
and milling project, the operator must decide where to site the
facilities and how to mine and process the ore in the most
economical and environmentally safe manner possible. His
decisions are influenced by many factors, one of which is a
continuing concern on the part of government and the public for
the effects of mining and milling on the environment and public
safety. This concern is manifested in a series of local, state,
and federal regulations covering all phases of the project from
the pre—mining stage, throughout the active life of the project,
to post—reclamation surveillance.
The purpose of this chapter is to highlight the regulations and
procedures that the operator incorporates in his project plans,
the environmental factors affecting location of mine surface
facilities such as the mill and tailings disposal sites, the
project activities and their impact on the environment, and the
objectives of monitoring, surveillance and reclamation. .
4-1
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4.1
Regulations, Standards and Guidelines
Various federal and state agencies prepare and administer
regulations and standards to insure public safety and to protect
the environment during development of uranium resources. These
agencies also issue guidelines to assist industry in obtaining
the required licenses and permits.
4.1.1
Regulatory Authority
The federal agencies primarily involved in uranium mining and
milling are the Nuclear Regulatory Commission (NEC) and the
Environmental Protection Agency (EPA). The NRC licenses and
regulates the nuclear energy industry to protect the. public
health and safety and the environment. It fulfills its
responsibilities through licensing and regulation of nuclear
facilities, which include uranium mills. It also develops
working relationships with the states regarding regulation of
nuclear materials such as processed uranium ore. The purpose of
the EPA is to "control and abate pollution in the areas of air,
water, solid waste, . . . and radiation" (U.S. Government Manual,
1976). . One of its activities is to coordinate and support
research and anti-pollution activities" by state and local
governments.. Several other federal agencies may also be
involved. For example, in the western states, federal lands are
administered primarily by the Bureau of Land Management (BLM) and
the U.S. Forest Service (USFS).. In addition to the BLM and USFS,
4-2
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the Bureau of Reclamation and the Bureau of Indian Affairs are
often involved in approval of rights-of-way or special land use
applications or operating plans.
Some of the NRC requirements and guidelines are:
• Requirement for Source Material License (10CFR40.31f)
• Requirement for Supporting Environmental Report (10CFR51)
• "Standard Format and Content of License Applications for
Uranium Mills," NRC Regulatory Guide 3.5 (Revision 1,
November 1977, distributed for comment)
« "Preparation of Environmental Reports for Uranium Mills,"
NRC Regulatory Guide 3.8, April 1973 (Being Revised
1978) .
« "Design, Construction, and Inspection of Embankment
Retention Systems for Uranium Mills," NRC Regulatory
Guide 3.11 (Revision 2, December, 1977)
• "Measuring, Evaluating, and Reporting Radioactivity in
Releases of Radioactive Materials in Liquid and Airborne
Effluents from Uranium Mills," NRC Regulatory Guide 4.14
(distributed for comment June 1977)
• "Quality Assurance for Radiological Monitoring Programs
(Normal Operations) Effluent Streams and the Environment,"
NRC Regulatory Guide 4.15, December 1977
• "Applications of Bioassay for Uranium," NRC Regulatory
Guide 8.11, June 1974. A Branch Position for uranium
mills is expected in 1978.
• "Instruction Concerning Prenatal Radiation Exposure," NRC
Regulatory Guide 8.13, November 1975, Revision 1
The NRC is preparing other guides for inspection and operation of
tailings ponds and for slurry pipelines. The NRC also prepares
branch position papers to serve as interim guidelines. For
example, the Fuel Processing and Fabrication Branch released
4-3
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"Branch Position: Uranium Mill Tailings Management" in May 1977,
which was later incorporated into Regulatory Guide 3.5. The
"Branch Position for Preoperational Radiological Environmental
Monitoring Programs for Uranium Mills" was released in
January 1978. Another branch position paper for operational
monitoring will be issued. Copies of NRC regulatory guides and
branch position papers may be obtained from the U.S. Nuclear
Regulatory Commission, Washington, B.C. 20555, Attention:
Director, Division of Document Control.
Some examples of the EPA water, air quality, and radiation
protection standards are:
ENVIRONMENTAL RADIATION. PROTECTION STANDARDS FOR NUCLEAR
POWER OPERATIONS (40 CFR PART 190, FEDERAL REGISTER,
VOLUME 42, NO. 9) were published January 13, 1977. New
dose limits for individuals were established to provide
protection for populations living in the vicinity of
uranium mills and other fuel cycle operations.
The standards specify that "operations... shall be
conducted in such a manner to provide reasonable assurance
that... the annual equivalent dose equivalent does not
exceed 25 millirems to the whole body,... of any member of
the public as the result of exposures to planned
discharges of radioactive materials, radon and its
daughters excepted, to the general environment from
uranium fuel cycle operations and to radiation from these
operations" (40CFR 190.10a). As defined in the standard,
the term "radiation" (40CFR 190.02e) includes (among
others) alpha, beta, and gamma rays, which are most
pertinent to uranium milling. The standard defines
general environment as the "total terrestrial,
atmospheric, and aquatic environments outside sites..."
(40CFR 190.02c) of fuel cycle operations, such as the
uranium mill site boundaries.
4-4
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When fully developed these standards will apply to uranium
mills and mill tailings. For instance, radon and its
daughters were not included in the initial standard. It
is expected that these standards will be updated as
additional data for the radionuclides become available
(Hendricks, 1977).
EPA LIQUID EFFLUENT GUIDELINES FOR ORE MINING AND DRESSING
(40CFR440, Subpart E) when revised will contain effluent
discharge limits. Presently the standards are suspended
by court order. Originally zero discharge limits were
specified.
RESOURCE CONSERVATION AND RECOVERY ACT (RCRA) OF 1976
defines solid waste to include all radioactive waste not
covered by the Atomic Energy Act of 1954, as amended.
This includes natural radioactive material and
accelerator-produced material. Those solid wastes to be
identified are being defined at this time in Section 3001,
"Identification and listing of hazardous waste."
EPA draft hazardous-waste criteria include radium—226 at
concentrations equal to or greater than 5 pCi per gram
(gm) of dry waste and/or 50 pCi per liter (1) of liquid
waste. Disposal of radioactive waste with activities
below this level would be regulated by the states using
RCRA Section 4004, Land Disposal Site Classification
Criteria. Waste exceeding the dry and/or liquid
concentrations of 5 pCi/gm and/or 50 pCi/1 will be
regulated by the EPA or a state through a
permit/enforcement regulatory program (RCRA Subtitle C)
O
A special study of mining waste is being conducted by the
EPA Office of Solid Waste. Following completion of the
study the standards for storage, treatment and disposal
(Section 3004) will be revised to define acceptable and
specific mining waste disposal limits and processes
(J.Yeagely, EPA personal communication, 1978).
Since the late 1950's, the states have greatly increased their
responsibilities for enforcing and monitoring federal standards
and for measuring and mitigating environmental effects of nuclear
development within their borders. Congress enacted Section 274
of the Atomic Energy Act of 1954, as amended in 1959 to recognize
the interests of the states in atomic energy, to clarify state
4-5
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and federal responsibilities, and to provide for states to enter
into formal agreement with the Atomic Energy Commission (now the
NRG) for regulatory authority over source, byproduct,- and small
quantities of special nuclear material (NEC, NUREG—0388, 1977).
States that have been delegated licensing authority for source
material under the Atomic Energy Act of 1954, as amended, are
called agreement states, and at this date . 25 states have
developed their own programs and entered into formal agreements
with the NRC. Kentucky was the first to become an agreement
state, in 1962, and New Mexico was the last, in 1974. Agreement
states, in order of effective agreement date, are:
1. Kentucky - 1962 . 14.
2. California - 1962 15.
3. Mississippi - 1962 16.
4. New York - 1962 17.
5. Texas - 1963* 18.
6. .a Arkansas - 1963 19.
7. * Florida - 1964 20,
8. North Carolina - 1964 21.
9. Kansas - 1965 22.
10. Oregon - 1965 23,
11. Tennessee - 1965 24.
12. New Hampshire - 1966 25.
13. Alabama - 1966
Nebraska - 1966
Washington - 1966*
Arizona.- 1967*
Louisiana - 1967
Colorado - 1968*
Idaho - 1968*
North Dakota - 1969
South Carolina - 1969
Georgia - 1969
Maryland - 1971
Nevada - 1972
New Mexico - 1974*
*States with licensing programs for uranium milling activi-
ties (Smith, EPA, personal communication, 1978)
States that have not entered into a formal agreement are called
non-agreement states. In these states, the NRC maintains its
regulatory authority. The non-agreement states include three
uranium-producing states: South Dakota, Utah, and Wyoming. In
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uranium-producing states: South Dakota, Utah, and Wyoming. In
non-agreement states, the NEC requires a Source Material License
to process or refine uranium ore once it is mined. The NRC
license requirements apply to ore that contains 0.05 percent or
more by weight of uranium or thorium or any combination of the
two prior to processing, such as grinding, roasting, or refining
(10CFR 40.Uh,k). Agreement states have been delegated (by
agreement) the authority for source material;, they issue a
Radioactive Material License, which is comparable to . the NEC
Source Material License.
4.1.2
Regulatory Procedures and Permit Requirements
The procedures and requirements for obtaining a permit to mill
uranium are similar for agreement and non-agreement states;
however, these vary from state to state and with each project.
Early during development of project plans the operator contacts
the regulatory agencies to coordinate compliance with their
requirements, which influence engineering and economic
feasibility of the project. The project team should work closely
with the agencies to insure completeness of the applications and
to develop a schedule that reflects their review procedures.
After clarifying what permits are required and what supporting
information is needed for each one, a program is finalized. The
applicant collects baseline data (including radiological data),
provides results of pre-mining investigations, prepares and files
applications, and submits detailed project plans.
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4.1.3
Proposed Legislation and Requirements
Additional or revised requirements may result from:
• SAFE DRINKING WATER ACT - The states are to develop
programs to protect existing and potential sources of
drinking water.
CLEAN AIR ACT AxMENDMENTS OF 1977 - The amendments
authorize EPA to set guidelines for certain radioactive
materials that are presently unregulated (P.L. 95—95,
sec. 122 (a)). The amendments also have significant
implications on uranium projects particularly in meeting
national ambient air quality standards (NAAQS) and
prevention of significant deterioration (FSD).
EPA policy has been that NAAQS and PSD increments need not
be attained on company property where physical access by
the general public is precluded by fence or other physical
means (Environment Reporter, February 1978). The EPA is
reconsidering the policy which may lead to a revised
definition of "ambient air" on company property. Uranium
mines and mills would be among sources significantly
affected by a policy revision.
The preceding comments are examples of changing regulations
prompted by new or revised legislation. The potential technical
and economic impact of the legislation during its formulation and
after enactment is well documented in comments and reports by
government and industry. Investigators and reviewers who need to
know more should consult the responsible agency and industry
groups.
In a non-agreement state, the applicant's environmental report
accompanies the application to the NRC for a Source Materials
License. The NRC then prepares a draft environmental statement.
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Agreement states have their own licensing procedures, which have
to be comparable to the NRC; however, an environmental impact
statement may not be required by some states. By example,
Table 4—1 shows the permits and time required for the Sweetwater
Project uranium mine and mill in Wyoming, a non-agreement state
(NRC, NUREG-OU03, 1977). The principal agencies involved were
the Wyoming Department of Environmental Quality (DEQ), the State
Engineer (SE), the Wyoming Industrial Siting Commission (WISC),
the U.S. Nuclear Regulatory Commission (NRC), and the Bureau of
Land Management (BLM).
When an applicant files for permits or license approvals, the
lead agency will request comments from the other agencies
involved. Comments will be incorporated into the environmental
statement. Project plans will be reviewed to determine if
regulatory and bonding requirements are satisfied and if designs
have been developed to control and mitigate environmental effects
and provide for the safety of the public.
Public hearings may be required once the lead agency review
process is complete. After the review and hearings the permit is
either granted or denied. The permit may be granted with
stipulations which often include performance bonds, specific
monitoring and post-reclamation procedures.
The concern about long—term effects of low—level radioactive
wastes has resulted in revised regulations for licensing uranium
mills and improving tailings disposal systems. The regulations
require stringent project decommissioning and post-reclamation
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X*"
Permit or License
License to Mine
Permit to Mine
Air Pernlt to Construct
Air Permit to Install Mill
Processing Equipment
Sanitary Sewage Disposal
NPDES (mine dewatering)
Mill Waste Water (tailings)
Potable Water Supply
Waste Treatment Plant
(Bad, treatment equipment)
Water Wells (18)
Tailing Impoundment
Mill Settling Pond
Mine Dewatering Settling Ponds
Right-of-Way
Access Road
Transmission Line
Access Road (Sweetvater
County)
Sand 4 Gravel Pit (mining)
Site Equipment Staging Approval
Industrial Siting Permit
Zoning Change
Final Impoundment
Air Permit to Operate
Industrial Waste Disposal Site
Source Materials License
Granting
Authority
DEQ-LQD*
DEQ-LQD
DEQ-AQDb
DEQ-AQD
DEQ-WQDC
DEQ-WQD
DEQ-WQD
DEQ-WQD
DEQ-WQD
SEd
SE
SE
SE
BLM6
BLM
County of
Sweetvater
DEQ-LQDf
DEQ-LQD8
WISCh
County of
Sweetvater
SE
DEQ-AQD
DEQ-SWMD^
NSC*
Date of
Application
Dec. 1976
Resubmitted Aug. 24, 1977
Dec. 1976
Resubmitted Aug. 24, 1977
May 1977
— —
~
Feb. 1977
Jul. 28, 1977
Jul. 28, 1977
Jul. 28, 1977
Jul. 28, 1977
Jul. 28, 1977
Jul. 28, 1977
Jul. 28, 1977
Feb. 1977
Dec. 1975
May 1977
Show cause hearing
Oct. 1976
Dec. 1975
Jul. 28, 1977
Aug. 1977
Nov. 1976
Date ^*N
Granted
Denied
In Review
Denied
In Review
Aug. 30, 1977
—
—
Jul. 1977
In Review
—
In Review
In Review
In Review
In Review
In Review
May 1977
Jan. 1976
Amended Jun. 1976
Jun. 1977
Jun. 1977
Mar. 19771
Apr. 1976
In Review
Withdrawn
Refiled Nov. 1977
In Review
Doming Dept. of Environmental Quality-Land Quality Div.
^Wyoming Dept. cf Environmental Quality-Air Quality Div.
cwyoming Dept. of Environmental Quality-Water Quality Div.
Wyoming State Engineer
eU.S. Bureau of Land Management
^Obtained via Sweetwater County Engineers Office
^Modification to existing DEQ-LQD Permit 302 for open test pit
"Wyoming Office of Industrial Siting Administration
%egative Declaration issued March 1977
^Wyoming Dept. of Environmental Quality-Solid Waste Management Div.
''U.S. Nuclear Regulatory Commission
SOURCE: NRC, DES, NUREG-0403,
December 1977
Table 4-1
Status of Approvals and Permits Required for the Sweetwater Project as of
November 1977
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procedures. . A Generic Environmental Impact Statement on uranium
milling (GEIS) is to be released by the NBC in the fall of 1978
which may alter future tailings disposal system designs and
modify recent license permit stipulations.
4.2
Factors Affecting Facilities Siting
Decisions for siting are made within a framework of engineering,
economic and regulatory requirements. The location of the mine
is limited to where the ore is; however, some options are
available for the mill location. Because the large tonnages of
ore have to be hauled to the mill from the mine, the mill should
be as close to the mine as possible. The cost of hauling many
thousands of tons of ore is one of the major production costs.
Another restriction that limits the location of the mill is the
need for disposal and storage of the mill liquid and solid wastes
remaining after ore processing. With these restrictions in mind,
several sites within the project boundaries are usually examined
to select the best site for construction and operation of the
mine's surface facilities and for a disposal site for mine waste.
Similarly, sites are selected for the mill and its large volume
of wastes. Economics also dictate that the facilities be located
so that they do not interfere with recovery of the ore. In
addition to these engineering and economic restraints, the
operator is required to design the mine and/or mill to comply
with environmental, safety, and .radiation protection standards.
Environmental factors considered in opening a mine and siting the
mill and waste disposal facilities include:
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• Topography
• Population
• Geology and geochemistry
• Hydrology, surface and groundwater
• Soils and overburden
• Meteorology
• Biology
• Seismicity
• Cultural features
These factors do not operate independently but are related to
each other. Por example, hydrology and meteorology are dependent
on the local topography. Topography, likewise, is controlled to
a large extent by geology. Meteorology at the site is affected
by hilly or rugged terrain, since the winds are sometimes
channeled along canyons, gullies and water courses.
4.2.1
Topography
The topographic features of a site influence the location of
facilities such as buildings, ore storage pads, and waste
handling an.d disposal impoundments. For instance, flat terrain
is favored for the location of buildings, storage pads and roads,
while sloping terrain is favored for gravity flow from the mill
to the set-tiling ponds and tailings impoundments. stable
topography is desirable for siting the permanent facilities.
Rapidly changing topography indicates rapid erosion or other mass
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wasting processes that can cause problems for mine and mill
facilities. Of particular importance is the reduction of erosion
potential for tailings impoundments.
The topography of a site and surrounding area also influences
other environmental conditions, such as meteorology, hydrology,
and biology. These influences are discussed in the sections
pertaining to the specific conditions.
4.2.2
Population
The proximity to the nearest resident and to important population
centers is of concern in deciding where to locate mills or other
facilities that discharge radioactive or chemical contaminants to
the environment. Population centers include humans, agricultural
plants and animals consumed by humans, economically or
esthetically valuable wildlife, and indigenous natural
populations that are important to the self-maintenance and
stability of ecological systems. "Proximity" refers to the
nearness of a pollution source to population centers and the
degree to which pollutants can contact such populations. The
estimated radiation dose is calculated based on populations
living within 50 miles of a mill using expected radioactive
effluent release estimates, on—site meteorological data, and land
use.and population data. If no radioactive liquids are to be
released, estimates are then prepared for particulate and gaseous
effluents. These estimates include mill and tailings site
characteristics, the mill equipment performance and exposure
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to man. Radionuclide doses to individuals are predicted at
reference locations such as the nearest permanent residence and
at the downwind project-site boundary.
4.2.3
Geology and Geochemistry
Geology is interrelated with the surface and subsurface features
of the site, the ore, the project activities and elimination or
reduction of environmental impacts. The types of rock materials
and their structure not only determine where ore will be found,
but influence surface drainage, ground water flows and soil
formation. This geologic information is basic to predicting the
fate of materials, particularly subsurface effluents. The
geochemistry of the sites are determined to show how uranium and
other elements and isotopes are distributed and how they may
migrate as a result of mining. Open pit mining will alter the
subsurface structure, soil profile, land form and hydrology of
the local area. To predict the effects of mining a geochemical
survey is conducted to provide rock, soil, overburden, plants and
water sample data.
The effects of geologic conditions upon the proposed project
construction and land use, and conversely the effects of the
project upon geologic processes and conditions in the area, are
evaluated to satisfy statutory requirements and/or guidelines.
For instance, "Recommended Guidelines for Preparing Engineering
Geologic Reports for Uranium Mill Siting, Radioactive Tailing
Storage and Associated Land Use Changes" was issued by the
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Colorado Geological Survey (CGS) in March 1978. The guidelines
include regulations of "the State of Colorado and the NRC.
4.2.4
Hydrology
The source, quantity, quality and movement of surface and ground
waters influence the design of mine facilities and the siting and
design of mill facilities and waste disposal systems. Water is
required for makeup for mill processes and domestic use.
Hydrologic systems can be- major pathways for movement and
transport of radioactive and chemical waste from mine and mill
sites to the environment. In cases where water for mill use is
taken from surface or ground water supplies, the impact of water
withdrawal on the supply must be evaluated. Depletion of surface
water flows and drawdown of local water tables are generally
regulated and must not exceed agency requirements, which vary
from state to state. The quality of water used for domestic
purposes should meet minimum requirements set by state agencies,
usually following the U.S. Public Health Service recommended
drinking water standards.
The National Pollution Discharge Elimination System (NPDES)
permit specifies discharge conditions in those instances where
surface waters are -to receive liquid discharges from a mine/mill
operation. Dilution capacity and water quality must be
determined 'to predict environmental effects in the event of
accidental releases and undetected seepage. Dilution capacity
increases with flow rate and turbulence of streams. Changes in
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water quality, such as sediment load and dissolved solids
content, which might occur as a result of an accidental mine/mill
discharge, may have a significant biological or esthetic impact
and possibly provide potential for food chain transport of
radionuclides and other contaminants to the human population.
Water systems are major pathways of radionuclide transport to the
environment. Radionuclides in seepage from tailings retention
systems can migrate downward into aquifers that may appear at the
surface as springs or seeps that may affect humans, crops, or
livestock. Conversely, radionuclides in surface waters,
resulting from aerial deposition or waste discharge, may enter
the ground water system by infiltration and affect ground water
supplies. Therefore, the relationship and interactions of
surface water with ground water must be understood.
The depth to the ground water table is important in the design of
mine dewatering systems. Where a mine penetrates the water
table, accumulated water must be removed (dewatering). The rate
of dewatering depends on the hydraulic characteristics and the
depth of penetration of the water table. In the majority of
cases, the natural ground water associated with uranium deposits
is not suitable for consumption because the radium content
exceeds state and' federal limits. This water may require
treatment to remove uranium, radium or other contaminants before
discharge to comply with, NPEES permit limitations. Depth to
ground water is also important in locating tailings disposal
areas, since a large distance between ground water and tailings
is desirable. Surface waters and natural drainages at or near
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prospective mine or mill sites should be examined for erosion and
deposition potential. High water runoff from rapid snow melt or
thunderstorms can dramatically alter stream channels and cause
severe erosion. This should be of particular consideration when
siting mill tailings retention systems and ore storage piles.
4.2.5
Soils and Overburden
The soils and overburden at a potential site are sampled and
tested to determine the following:
• Chemical and physical properties
• Presence and concentration of radioactive or toxic
materials
• Reclamation potential
• Suitability for construction of embankments
• Suitability for construction of surface facilities
• Susceptibility to erosion by wind and water
The analyses of soils and overburden are routinely performed to
evaluate project sites. The relationship of the soils and
overburden to radioactive or toxic materials movement at the mine
and at mill sites is also part of the evaluation.
Soil and sediments usually become a major reservoir for
potentially toxic or radioactive materials at mines and mills.
Material particles are subject to wind erosion and off-site
migration, depending upon particle size, moisture content,
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vegetation cover, wind speed and other factors. In an open-pit
operation overburden properties are determined, since it is often
stored, backfilled or used as a substrate in reclamation. Soil
properties which affect dispersal of these materials in the
environment include porosity, permeability, ion exchange
capacity, and erodibility.
If tailings are to eventually be covered with topsoils from the
site, the porosity and diffusion coefficients which affect radon
diffusion should be known. In general, clay soils provide a more
efficient barrier to radon migration than coarse-textured soils.
Clay is also somewhat advantageous as a substrate for tailings
ponds because of its large capacity to adsorb and retain
dissolved radionuclides (Whicker and Johnson, 1978). High
adsorption capacity of soil and geological substrate can provide
effective protection of subsurface aquifers from radionuclides
and undesirable chemicals. The textural .properties of surface
soils also affect erosion potential and thus determine their
suitability in tailings management and reclamation.
The nature of soil and earth materials in contact with surface
and subsurface water affects surface water exchange of dissolved
minerals and hence, radionuclide migration. In general, the
greater the ion adsorption capacity of such materials, the more
effectively elements and radionuclides will be retained near a
mine or mill site and result in lower concentrations of dissolved
radionuclides in water. A disadvantage of fine-grained, highly
adsorbent sediments in surface drainages is that they are subject
to scouring and long-distance displacement during high water
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runoff periods. In some cases, adsorbent clay beds are
advantageously protected by overlying gravel and boulders in
streambeds.
4.2.6
Meteorology
Meteorological conditions influence the dispersion and deposition
of airborne effluents, such as stack releases or resuspension of
radionuclide-tear.ing particles eroded from ore or from dry mill
tailings. Wind direction determines, the overall directional
spread of airborne materials. A representative "wind rose" is
used to evaluate proposed mine or mill sites. A wind rose is a
graphic representation of wind direction and speed frequencies
based upon data gathered over some period of time. These data
are used to predict prevailing wind direction, mean wind speed
azimuth, and frequency of occurrence.
Understanding wind speed regime is necessary to predict
radionuclide movement in the vicinity of a mine or mill site and
to design an appropriate monitoring program when operations
begin. Sources of airborne radioactivity dispersed in the
atmosphere largely by wind action are radioactive 222Rn gas,
which.emanates from uranium ore and from mill tailings; small
particles of yellowcake, which are released from dryer stacks;
and ore and mill tailings dust generated by human activity or
wind resuspension. According to typical Gaussian plume models
(Turner, 1970; Smith, 1968), the air concentration at some point
downwind of a source is inversely proportional to the mean wind
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speed which acts upon a plume. Thus, higher mean wind speeds
will usually reduce air concentrations and potential radiation
doses downwind from such sources.
Another meteorological feature which affects atmospheric
dispersion of air—borne materials is the vertical stability of
the atmosphere. Vertical stability depends largely upon the
temperature structure of the atmosphere. Unstable conditions
promote mixing of air—borne contaminants with the atmosphere and
stable conditions do not. Vertical stability is often described
by the Pasguill stability category (Turner, 1970), which can be
predicted reasonably well from wind speed and solar insolation or
wind direction variability (wind sigma) data. These data vary
according to regional and local topography, the capability of the
earth's surface to absorb and reflect solar radiation, and other
factors.
Precipitation influences the migration of materials from mine and
mill sites. For instance, precipitation increases surface
moisture which in turn stabilizes otherwise win.d-erodible soils.
On the other hand, high runoff- may cause undesirable water
erosion of ore and tailings. Precipitation also removes
particles from the atmosphere through the processes of "washout"
and "rainout" (Slade, 1968). This can affect the spatial
distribution of radionuclides as well as their route of intake by
animals. Precipitation patterns also affect ground water and the
subterranean migration of radionuclides. Moisture can also
affect the rate of radon emanation through soil cover,
particularly in a ground frost situation.
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The tendency for ore and tailings dust to become resuspended and
entrained in the air stream as well as the process of saltation
increases sharply with wind speed, in fact, some studies have
shown that soil movement is proportional to the cube of the wind
speed (Skidmore, 1976). The net effect of wind speed upon
radiation doses around uranium mines and mills depends on the
nature of the ore and tailings as well as other factors. .
Therefore, a general statement cannot be made as to the
feasibility of windy sites, except that the problem is complex
and should be evaluated for each potential site.
4.2.7
Biology
The ecology of a prospective site and the surrounding area may be
affected by mine and mill operations. Of primary concern are the
kinds and numbers of organisms and their direct value to man, or
their value for maintenance of the character and stability of the
environment. Sound management decisions are particularly
important if potential sites are on or adjacent to lands with
crops, domestic livestock, important game and fish species, or
rare or endangered wildlife, because the consequences of
operational mishaps or accidents such as tailings dam failures
would be worse in such areas than in biologically unproductive
areas. Furthermore, food-chain transport of radioactive
materials and heavy metals under normal operations may be
enhanced in areas that are productive in agriculture, fish or
wildlife.
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Agriculture, crops and livestock operations adjacent to a mine-
mill project have considerable potential to become contaminated
with radionuclides or toxic materials like selenium or
molybdenum. Cases have existed in the past where contaminated
irrigation water and dust from operations have resulted in
contaminated crops, and milk and meat products, which constitute
part of the human food chain (Whicker and Johnson, 1978). A case
of molybdinosis in cattle was reported near an operation where
uranium was recovered from lignite ash (F. Smith, EPA personal
communication, 1978). While the radiation or toxic exposures to
crops, livestock and humans resulting from such contamination may
be acceptable and within standards and regulatory guidelines,
such exposures can be minimized through careful site selection
and appropriate environmental controls.
Fish and game species have economic and ecological values in
themselves, and in addition are consumed to varying degrees by
humans. Fish and wildlife can use areas not readily controlled
by human intervention. For example, waterfowl can use ponds
associated with mines and mills, become contaminated, leave the
area, and then be consumed by humans* Most terrestrial wildlife
can cross ordinary fences and feed adjacent to a tailings
retention system and ingest contaminated soil and vegetation.
Certain animals can burrow into dams or reclaimed tailings piles,
reducing the integrity of the stabilization materials. Fish can
concentrate to a remarkable degree certain radionuclides which
enter watercourses. For these and other reasons, siting
decisions should give due consideration to natural populations
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and to a reduction in radioactive emissions,
4.2.8
Seismicity
Earthquakes have the potential to disrupt the integrity of
tailings dams, mine structures and mill processing facilities.
Ground motion and subsequent dynamic response could cause
structural failures which could result in the release of
radioactive and chemical materials to the environment. Siting
and design of mines, mills, and waste retention systems should be
consistent with the probability of damaging ground motion. Zones
of specific earthquake magnitude have been delineated on a
regional basis, and specific sites can be examined locally for
faults and other evidence of geologic instability. For
seismicity information in the U.S. see Algermissen and Perkins
(1976), Coffman and von Hake (1973) and NOAA (1973).
4.2.9
Cultural Features
Historical and , archeological sites in the project area may
require special consideration in the location of mine and mill
facilities. These include natural landmarks and historic sites
or areas listed in the National Registry of Natural Landmarks
(37 CFR 1496) or the National Register of Historic Places.
Contact with the State Liaison Officer - Historic Preservation or
Historic Preservation Officer is usually required. Procedures
for protection are given in 36 CFR 800.
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The archeological significance of the site must also be
determined. Steps to recover historical or archeological data
are required by the Historic and Archeological Preservation Act
of 1974 (PL 93—291), and may affect the development of a project.
4.3
Non-Radiological Impacts
The potential for environmental impacts from uranium mines and
mills is greatest during the operational phase of the project
when ore is extracted, transported and milled, and wastes are
disposed of. The importance of environmental concerns which are
generally associated with a uranium project varies with the type
of project, method of operation and a multitude of site-related
characteristics. Therefore, it is not possible to qualify
potential impacts, or in many cases even to predict if they will
be significant, until after the project is defined. The project
operator has the responsibility to limit operational impacts to
acceptable levels, and he must provide evidence of this in
environmental reports or other documents which are required to
license the project. In all cases, as a condition of licensing,
impacts will be limited to comply with regulations set by federal
and state agencies to protect the health and safety of the
public. In order to limit environmental impacts to acceptable
levels, it is necessary to:
s 'X
• Identify potential impact sources
« Assess the importance of impacts from these sources
• Control impacts, when necessary, by employing specific
design or operational measures
4-24
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The . potential non-radiological impacts for a mine and mill
include changes in land use, topography, surface and ground water
quality, air quality, and biology and soils.
4.3.1
Land Use
Mining and milling operations which remove land from other uses
for the duration of the project include:
Exploration and pre-mining investigations
Mine development and operation
Overburden disposal
Ore stockpiling
Roads for access and ore haulage
Utility corridors
Table 4—2 lists the amount of land that has been used for various
uranium projects. It is readily apparent from this table that
specific land requirements cannot be generalized or predicted
from the type or size of an operation. The impacts are more a
function of location and size of ore deposits, mining and
extraction methods, and duration of activity.
The land use impacts are mitigated by disturbing as little area
as possible and by reclaiming the areas disturbed after
operations cease, as discussed in section 4.5.
Although most states require reclamation back to productive use,
the land use capacity in some areas may be permanently altered.
4-25
-------
Proleet
Mill Mine
Present Proleeted Talllnga Road« Peuaterlnn
Total
Lucky HcMlne
Caa aill», Vyoalng
(open pit-acid leach)
Bur Creek Project
Convena County, Wyoming
(open pit-acid leech)
Sheruood Project
Spokane Indian Raaarv.,
Washington
(open pit-acid leach)
Irlgaray Project
(in-aitu)
Suaetvater Project
Red Desert, Wyoming
(open pit-acid laach
and Heap leach)
Union Carbide
Caa Bills, Wyoming
(open pit-acid leach)
Rio Algom Mine
Hoab, Utah
(underground nine)
aill and tailings
Atlas
Hoab, Utah
•ill and taillnga
50 2550
130
40
5
87 (4001)
2232 1300
230 occupied
500 alte
500
2060
1600
150
153 104
155 106
1000 —
300
leaa than 1
(2-13* holea
plua head
atructurea) 25
3150
30
3450
no average
(supplies
fron «T30
different oinaa)
(included
la mill)
320
—1000
-.6000
1725
27
2SO
Heap leach and reclamation
2Iocludea tailing*
SOURCE: Compiled by SHZC
Table 4-2
Approximate Land Requirements (in acres) for Various Mine and Mil! Activities
4-26
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For instance, waste disposal areas such as overburden dumps and
tailings piles would have restricted grazing if a vegetation
cover were not reestablished or if radioactive releases were not
controlled. The highwall and pit left after open pit mining
would constitute a permanent alteration in land use capability,
unless reclamation were undertaken.
4.3.2
Topography
Some topography alterations occur as part of any project
operation. Large topographic changes may result from open—pit
operations, which generally leave a highwall, a small pit, and.a
spoils disposal area higher than the local terrain. Also, the
construction of mill tailings impoundments and the deposition of
tailings into them creates a permanent change in topography.
Additional minor changes are caused by roads and other
transportation facilities, leveling for construction, drainage
diversions, and construction of heap leach pads and in—situ
facilities in some proposed operations.
433
Surface and Ground Water
Surface and ground waters in the vicinity of uranium projects may
be affected by a number of project—related activities.
The. significance of a particular potential impact on site
hydrology is closely related to the type of project, method of
operation, and specific site characteristics. Activities which
have potential for hydrologic impact include the following:
4-27
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,
' • Mine dewatering
• Water makeup requirements
• Liquid waste disposal
• Surface runoff
Mine dewatering is required when a surface or underground mine
penetrates the local ground water table. Water accumulates in
the mine and must be removed so that operations can continue.
Mine dewatering may affect surface and ground water in three
ways: 1) by lowering the local ground water table, 2) by changing
the water quality in surface and ground water systems, and 3) by
increasing the flow in local water systems. Localized lowering
of the ground water table (drawdown) usually results from
dewatering activities and may interfere with the production of
wells drawing from the same aquifer or from a hydraulically
connected aquifer. Dewatering may also change the quality of the
ground water. As water is continually removed, transport of
water from surrounding areas to the area of pumping will occur.
If this water is of different quality than the local water, a
change in composition will occur. Surface water quality and flow
may be changed if mine water is discharged. The magnitude of
these changes is dependent on the respective volumes and
compositions of the discharge and receiving water. The discharge
of mine water would have to comply with NPDES permit limitations.
Water makeup requirements for uranium mills are reported to range
from 230 to 400 gallons of water per ton of ore for acid leaching
4-28
-------
circuits and approximately 60 gallons per ton for an alkaline
leaching circuit. Mills using the acid leach process require
more water than mills using alkaline leaching because more of the
alkaline leach solution may . be recycled. Makeup water is
obtained from mine dewatering or from wells. In general, the
withdrawal of makeup water used in a uranium mill does -not
adversely impact local water supplies.
Liquid waste disposal is required in the operation of
conventional acid and alkaline leach mills. In most cases, the
wastes are mixed with spent tailings to form a slurry, which is
transported to the tailings disposal area; discharge of wastes to
surface waters is not generally practiced. There is generally
some recycling of sluice water. • The primary waste produced is
spent leaching solution, which also contains small amounts of
organic process solvents, mostly kerosene. Organics lost to
tailings ponds have been reported to be 20 and 160 gpd for
1000-tpd mills and 3000-tpd mills, respectively.
Liquid waste disposal may impact surface and ground water
quality. Since liquid wastes are generally impounded with mill
tailings, the primary impact of disposal will result from seepage
from the tailings pond. Seepage will affect the quality of
surface and ground water. The amount of seepage of tailings
solution from the pond depends on the depth and size of the pond,
the tailings placement and dam construction, the soil
encountered, and liner, if any, used. Two reported seepage rates
are 45 gpm and 75 gpm for 50—acre and 150—acre impoundments,
4-29
-------
respectively. Seepage in recent impoundments has been reduced by
impervious clay and plastic liners.
Seepage from the tailings impoundment system may have high
concentrations of dissolved solids, including heavy metals, and
will increase the concentration of these materials in the ground
water. Of particular concern are the metals which exhibit higher
solubilities at low (acidic) pH and are leached from the ore with
uranium in acid leaching. Alkaline leaching is a more selective
uranium leaching process and does not dissolve as many metals as
acid leaching; therefore, the impact of a unit volume of acid
leach tailings solution on dissolved metals concentrations in
ground water is greater than for a unit volume of alkaline leach
tailings solution. Also, the alkaline leach process produces
approximately one—fifth tha liquid waste volume of the acid leach
process. The quality of surface waters may be altered if ground
water reaches the surface.
Surface rungff from disturbed areas may affect the quality of
surrounding water and may cause erosion. Due to differences in
material characteristics, surface runoff from overburden and
waste rock dumps may contain dissolved solids not normally
present in surface runoff. Also, prior to reclamation, surface
runoff can carry sediments from disturbed areas, including
tailings impoundments. This runoff may impact local water
quality. Since overburden dumps and backfilled mines (surface
mines) contain material that has been excavated and not
recompacted to its original density, runoff characteristics from
these areas could be different than from surrounding material.
4-30
-------
These differences could result in an alteration of local surface
and ground water characteristics and quality.
Reducing Hydrological Impacts
The. impacts of the operation of uranium mines and mills on
surface and ground water systems can he reduced or mitigated in
most cases. Although the lowered ground water table resulting
from mine dewatering is unavoidable, interference with the
production of local wells may be overcome by deepening existing
wells, drilling new wells or providing an alternate source of
water. Mine water can be used within the project for dust
control and mill makeup to reduce the quantity of water
discharged, thus reducing the impact on the receiving water body.
Seepage of liquids from the tailings impoundment may be reduced
by proper impoundment location, distribution of tailings behind
the dam, and installation of an impermeable liner. Because
complete elimination of seepage is difficult due to faults that
develop in the liner, the ground water needs to be monitored
periodically.
Runoff and dam seepage may be collected by a smaller, second dam
downstream of the impoundment and returned to the tailing
impoundment, thus preventing discharge of tailing solutions to
surface waters or drainages. Drainage ditches are, employed to
divert.runoff from the overburden dumps and from the tailing area
to minimize the quantity of precipitation entering these areas.
Solution mining impacts are different from those of conventional
4-31
-------
mining and milling, primarily because leaching solution is
injected into the ore body. 'This process changes the quality of
ground water in the uraniferous aquifer. The migration of
leaching solution from the field is controlled by changes in the
pumping rate (injection and withdrawal) of solution. At the
completion of operations at each facility, ground water will be
recirculated and -created to restore water quality to an
acceptable level. Disposal of liquid wastes is usually by
ponding, and seepage from the ponds may alter water quality, as
previously discussed.
Heap leaching is a process used to recover uranium from low—grade
ore and tailings from abandoned mills. Process water
requirements for heap leaching have been estimated to be
•
approximately 200—300 gallons per ton of ore. Since this water
is completely recycled, makeup is only required to replace losses
such as evaporation. After a water inventory has been achieved,
makeup requirements are low. In 'a properly constructed and
operated heap leaching facility, there should be no liquid waste
discharge. All process water (that is, leaching solution) is
recovered and recycled to the heap leaching area or to the
uranium mill as makeup. Seepage of leaching solution to ground
water may occur if the pads for the heaps are not impervious or
are faulted. Leaching solution would be of low pH with a high
concentration of metals, and could affect local ground water
quality. Proper construction of the pad minimizes seepage from
the heap.
4-32
-------
4.3.4
Air Quality
Uranium mining and milling produce two types of air—borne
contaminants— gaseous wastes and fugitive dust. Typical
air—borne emissions from mills are listed on Table 4.3.
Gaseous wastes result from the combustion of fuels in mining and
from vaporization of mill process fluids. Mining equipment is
frequently diesel or gasoline powered, and the combustion
products are discharged to the atmosphere. The combustion
products of concern are unburned hydrocarbons, carbon monoxide,
nitrogen oxides, sulfur oxides, and suspended particulates. The
quantity of combustion gases released to the atmosphere depends
on the number, size and types of mine equipment used and is
increased by on—site generation of process steam and electricity.
Typical air—borne emissions from heavy equipment are given on
Table 4.4.
Although fuels presently used for on—site generation (e.g.,
propane and light fuel oil) are relatively clean, use of coal in
the future may result in increased emissions of sulfur oxides and
particulates. Gaseous wastes occur in the milling process in the
form of vaporized fluids. These wastes occur in the process area
itself (that is, the mill building) and from pond and tailings
impoundment surfaces. Since the majority of uranium mills
operate with an acid leach circuit, more experience with this
process is available than for the other listed processes. Fluid
vaporization from alkaline leaching circuits has been estimated
to be very low. Ammonia releases from in—situ leaching (ammonium
4-33
-------
Process Liquids Vaporization
Sulfur trioxide
Hydrocarbons
Chlorine
Ammonia
Acid. Leach
0.2-2 Ib/day
100 - 180 Ib/day
0.2 - 0.4 Ib/day
Alkaline Leach
In-Situ Leach
Heap Leach
ME
NE
NE3
NE NE
NE NE
55 - 80
Yellowcake Dust
Fugitive Dust from
Dry Tailings Surface
0.25 - 5 Ib/day
O.A - 4 Ib/acre-hr
2.5 Ib/day
0.4-A.lb/acre-hr
3
3
Hydrocarbons are primarily kerosene with small amounts of amines and alcohols
Based on ammonium carbonate as the llxlviant
Values not reported but would be within range for an acid leach mill of similar size
SOURCE: Compiled by SWEC
Table 4-3
Typical Airborne Emissions from Uranium Mills
-------
Surface Mine
Underground Mine
I
Co
en
Carbon Monoxide
Hydrocarbons
Nitrogen Oxides
Sulfur Oxides
Suspended Particulates
Mining
Ib/day
295
36
485
36
17
Stripping
Ib/day
328
54
539
40
19
Ib/day
42
7
68
5
3
* Reported values increased to the next whole number
SOURCE: EPA, Assessment of Environmental Aspects of Uranium Mining and Milling,
EPA 600/7-76-036, December 1976
Table 4-4
Estimated Emissions from Heavy Equipment at Surface and Underground
Mines
-------
carbonate lixiviant) are primarily from lixiviant storage
treatment and disposal pond surfaces.
Fugitive dust is produced in both mining and milling. In the
mining process, it is produced from vehicular traffic (primarily
ore transport), and its impact is generally limited to the
vicinity of the mine and haul roads, except under adverse
meteorological conditions. Mining also produces dust from
overburden and ore handling. In the milling process, yellowcake
dust can be released.into the atmosphere. The primary impact of
fugitive dust is discussed under the effects of mining on
vegetation in Section 4.3.5. .
Reducing Air Quality Impacts
Mitigation measures to contain gaseous wastes are usually
unnecessary because the quantities released into .the atmosphere
are small and have little impact on ambient air quality. In
addition, fuels used for combustion are relatively clean fuels
such as propane and light fuel oil, although burning of coal may
increase in the future. Vaporization of process fluids generally
occurs at a low rate, and the impact on ambient air quality is
negligible. Some organics (mostly kerosene) may be contained in
the mill tailings and can evaporate; however, since the quantity
of organics is low and evaporation is primarily from the surface
of the tailings area, the rate of release is low and the impact
on ambient air quality is also negligible.
Fugitive dust from vehicular traffic and ore crushing and
4-36
-------
handling may be minimized by using wet processes and dust—removal
equipment.
Yellowcake dust resulting from drying and packaging is generally
recovered, and the impact on suspended particulate levels is
negligible.
43.5
Biology and Soils
Loss and displacement of soils and destruction of vegetation and
wildlife habitat are impacts of mining and milling. The removal
of vegetation and soils from disturbed areas represents a loss of
primary biological productivity on which the local ecosystems
depend.. Some areas, such as the mine and waste dumps, will be
temporarily distrubed and will be reclaimed during mining. Other
areas, such as the mill site, tailings disposal area and roads,
will be reclaimed after operations cease.
Soils are severely disrupted by most mining activities. Soils as
pedogenic units have developed into horizons by natural processes
of weathering and biological activity. These soil units are
destroyed by removal, transport, and stockpiling. The character
of replaced soils will change and, if left stockpiled for long
periods of time, will lose the soil organisms responsible for
decomposition and nutrient cycling. These soil biological
processes are only slowly restored in soils, and may cause
reduced plant growth during the early revegetation stage.
Fertilizing can partially compensate for the reduced biological
soil activity. Vegetation can be affected from dust deposited on
leaf surfaces, which may reduce plant vigor. This occurs usually
4-37
-------
along dirt roads and in the immediate vicinity of mines. The
problem is minimal and of short duration.
Wildlife effects are related first to direct loss of animals by
construction and mining activities and, secondly, by the loss of
food and shelter when plant cover and habitat are destroyed.
There is permanent loss of habitat during the life of a project
by roads and buildings, and mostly a temporary loss of areas
disturbed by mining activity, such as an open—pit operation.
Underground mines generally disrupt such small acreage that the
effect on wildlife is insignificant. Increased human populations
and travel to mining and milling activities impact wildlife such
as large mammals and predators that are not tolerant of human
disturbances. Other problems are associated with increased human
activity and include poaching and shooting of animals in the
vicinity of remote projects, increased traffic and road kills,
and the use of off-road vehicles.
Mine dewatering may occasionally create temporary aquatic habitat
where none previously existed. The effect of new aquatic habitat
may increase production and provide habitats for waterfowl and
aquatic organisms. One possible detrimental effect of additional
water is that the survival of wildlife that may come to depend on
it would be threatened by its removal (Wyoming Game & Fish,
personal communication).
The impacts on biology and soils can be reduced by reclamation
procedures, as discussed in Section 4.5.
4-38
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4.4
Radiological Impacts
iMan is subjected to low-level exposure from natural radiation
sources that are a part of the natural ambient environment.
These uncontrollable exposures result from radioactive materials
in the earth's crust, radionuclides in air and water, and cosmic
radiation (EPA, 1977). As a result also of man's activities, he
is subjected to additional exposure, which can be controlled.
These radiations have been called technologically enhanced
natural radiation (TENR) to distinguish them from natural
terrestrial and cosmic radiation (EPA, 1977). TENR can result
from a number of sources, including weapons testing, medical
treatment and diagnosis, uranium mining and milling, fertilizer,
supersonic air travel at high altitudes, and burning of fossil
fuels,
In uranium mining and milling, only 10—15 percent of the
radioactive material in the ore is removed; the remaining
85—90 percent remains in mill tailings. The mining and
processing increases the potential for TENR to human populations
and ecosystems in the vicinity of uranium projects. . Such
exposure has the potential, if not controlled, of increasing
genetic and somatic effects, such as cancer in occupationally
exposed workers and others near a mine or mill. The dose
commitment to populations around uranium mines and mills is only
a fraction of natural radiation doses and is also much less than
medical radiation doses. Quantitative comparisons between
radiation dose from natural background radiation, from medical
4-39
-------
sources and from uranium facilities are provided for a proposed
uranium mill in the Chapter U appendix.
The annual dose commitments to individuals and populations in the
vicinity of a uranium mill are predicted and supplied with the
application for a new or continued NEC Source Material License.
Included in the supporting data are radiation dose rates from the
natural environment in the area and a comparison of annual dose
commitments -to individuals with respect to existing and future
regulations. These data provide a perspective as to the
contribution from new or continued operations.
A -summary of dose rates from the natural environment is presented
on Table U.S. The existing radiation environment shown is
composed mainly of secondary cosmic radiation, cosmogenic
radioactivity and terrestrial radioactivity and radiation from
offsite sources such as other uranium mining and milling
operations. The specific dose rates for the natural radiation
sources of exposure are contained in the referenced. NRC Draft
Environmental Statement, NttREG—0439, April 1978.
For -Wyoming the radiation dose equivalent rate from the natural
environment is estimated to be about 185 mrem per year.
Additional site-specific natural radiation background data may be
required, especially that concerning the radon level for the area
to detail the site-specific levels for the project..
The evaluation of radiological impacts is in part based on the
predicted annual dose commitments to the whole body, skeleton,
lungs, and bronchial epithelium resulting from normal operations.
4-40
-------
Dose, mrem/yr
Source of Exposure
Cosmic radiation
Direct
Co smog en ic radionuclides
Terrestrial radiation
Internally deposited radionuclides
Inhaled radionuclides (chiefly Rn-222)
Total Dose Rate
Whole-Body
77
1
88
20
___
186
Bone
77
1
70
45
_ -
193
Lung
77
1
88
20
1.0C
187
Bronchial
Epithelium
-
-
-
-
625
625
These doses are typical of the general region; exposure levels fluctuate from area
to area, and other data may vary because of this.
Outdoor dose equivalent rates; shielding from building structures is not accounted for.
Inhalation dose due to radon daughters is expressed as dose to the bronchial epithelium.
SOURCE: Adapted from U.S. Huclear Regulatory Commission, DES NUREG-0439 pg 2-29 April 1978.
Table 4-5
Summary of Typical Radiation Dose Rates from the Natural Environment in the Wyoming area
-------
Table 4—6 summarizes the predictions for dose commitments for an
operation in which burial of tailings in clay—lined pits above
the water table would be used. The predictions indicate that
they are less than the present NRG dose limits for members of the
public outside of the restricted areas (10 CFR Part 20; Standards
for Protection Against Radiation) and the proposed EPA standard
for annual dose commitment (40 CFR 190). In this case the
nearest permanent resident was 6.8 miles north of the proposed
mill (NRG, NUREG-0439, April 1973).
The population dose commitments were also calculated and found to
be "only small fractions" of the dose received from natural
background radiation and "also small" when compared to the
average medical and dental X—ray exposures currently given to the
public for diagnostic purposes (NRG, NUREG-0439, April 1978).
The EPA standard does not yet specify the value for doses from
222Rn daughters.
The principal radiological concerns related to uranium mines and
mills are:
« Movement of radionuclides in the environment
• Biological effects of radiation
• Control of radioactive wastes and emissions
4-42
-------
Receptor Organ
Estimated Annual
Dose Commitments,
mrem/yr
Radiation Protec-
tion Standard,
mrem/yr
Fraction of
Standard
Whole body
Lung
Bone
Bronchial epithelium
Whole body
Lung
Bone
Bronchial epithelium
0.08
0.28
0.26
PRESENT NRC REGULATION (10 CFR 20)
500
1500
3000
0.0000145 (WL) 0.033 (WL)
FUTURE EPA STANDARD (40 CFR 190)
0.08 25
0.28 25
0.26
0.0000145 (WL)
25
NA
0.02
0.02
0.009
0.04
0.3
1.1
1.0
NAb
Radiation standards for exposures to Rn-222 and daughter products are expressed in Working
Level (WL). WL means the amount of any combination of short-lived radioactive decay products
of Rn-222 in one liter of air that will release 1.3 x 10-> mega electron volts of alpha
particle energy during their radioactive decay to Pb-210 (radium D).
Not applicable, since 40 CFR 190 does not include doses from Rn-222 daughters.
c
Nearest private residence 6.8 miles north of proposed mill.
SOURCE: USNRC, DES, NUREG-0439, April 1978.
Table 4-6
Comparison of Annual Dose Commitments to Individuals with Radiation
Protection Standards
-------
4.4.1
Movement of Radionuclides in the Environment
Uranium ore contains naturally occurring isotopes of the element
and a series of radioactive progeny which are formed by the
radioactive decay of parent materials. These radionuclides have
the potential for movement in the environment through a number of
pathways. A generalized scheme illustrating the principal
radionuclide transport pathways around uranium mines and mills is
given on Figure 4—1. The boxes represent compartments, or
"reservoirs," which contain radioactive materials, and the arrows
represent flows or transfers between the compartments. The major
processes or mechanisms which cause such transfers are indicated.
Not all possible transfer pathways are shown in order to simplify
the diagram, but the pathways that are usually of major interest
f
are given. The radionuclides of principal concern are also
indicated for some of the pathways. While losses of
radionuclides may occur in the system depicted by dispersion in
air and water, these losses are not shown. A more detailed
description of the radionuclides involved and their transport
pathways is given in the Chapter 4 appendix.
The abundance of these .radioactive materials depends primarily
upon the grade of the ore, which in turn is dependent upon the
geological and geochemical history of the ore deposit. The ore
body, when exposed to the environment through mining, can serve
as a source of radioactivity. Dissemination of radioactive
material from an ore body may occur by three mechanisms:
4-44
-------
^.
Ln
SOURCE: Whicker and Johnson, 1978
NOTE:
IKE RADIOACTIVE ELEIENTS OF PR III ART CONCERN ARE
INDICATED Bt ORDER OF IMPORTANCE IN PARENTHESES.
RnO • DAUGHTERS OF 222Rn. U • 23BU.
' Tn.230.234It). Ri-226Bj P1) . 2IOP|))
AND Po - 2IOPO.
SION OF
ICLfS
Mine & Mill
1
SEEPAGE
f SURFACI
Ground Water
1
RADON EMANATION
t IAIER TABLE
INGESTION
ADSORPTION
I UPTAKE
L
Aquatic
Invertebrates
INGESTION
INGESTION
(Ra.Pu.Po)
Figure 4-1
Transport and Movement of Radionuclides to Man
-------
• Emanation of radon gas
• Movement of radionuclide-bearing particles from the
surface of the ore body by physical disturbance
• Leaching of the ore body by mobile ground water
Radon gas (222Rn) a daughter product of the uranium decay series,
can emanate from the ore body and reach the atmosphere as soon as
the ore is exposed in a shaft or open pit. Radon also emanates
from the ore in transit and in stockpiles. The rate of radon
release is greater with higher grade ore, increased porosity and
exposure to the atmosphere. The decay of 222Rn forms a .series of
radioactive daughter products whose fate depends largely upon the
dispersion characteristics of the air in contact with the ore
body and the physical nature of the surroundings.
The movement of radioactive particles of ore from the ore body
depends upon the physical characteristics of the ore, such as
texture and cohesiveness and the physical disturbance to which
the ore surface is exposed. Dry ore sometimes generates
considerable quantities of radioactiva dust as it is mined. Ore
stockpiled on the surface, awaiting the milling process, is
subject to wind erosion, particularly if it crumbles to form
loose particles. Radioactive emissions may result from crushing
and grinding of ore, yeliowcake drying and disposal of tailings,
which contain only a little less radioactivity than the raw ore
(except for uranium).
Like- exposed ore bodies, mill tailings are subject to radon
4-46
-------
emanation, erosion by precipitation and wind resuspension, and
leaching of radionuclides into the ground water. Tailings are
also subject to limited invasion by plants and animals that can
transport radionuclides. The chemical processes within the mill
may convert some of the radioactive materials in tailings to more
soluble, biologically mobile forms than were in the ore.
The actual 'quantities of radionuclides released to the
environment from uranium mines and mills are subject to many
variables and therefore differ.from site to site. However, some
data are available on estimated or measured release rates for
currently operating mines and mills. Data for mills are more
plentiful than for mines.
The major pathways by which radionuclides are dispersed to the
environment are (1) aerial transport of dusts and gases and (2)
liquid discharges (see Appendix). • Aerial transport of
radionuclides may extend well beyond the boundaries of an
operating facility. Some approximate figures estimated for
airborne release rates from various sources at "model" or typical
uranium mills in New Mexico and Wyoming are presented in
Table 4—7. It is evident that the release rates vary by source
and that 222Rn release rates are far greater than for the other
radionuclides. This immediately calls attention to 'radon and
progeny for radiation exposure to populations in the environs of
a uranium mill.
There are different contributions by source between acid— and
alkaline-leach mills, but the total release quantities are
4-47
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ore crusher & bins
yellow cake
tailings pond
tailings beach
5
85
-
1
5
1
-
5
5
2
-
9
5 5
2
-
1 8
5 5 37,000
- - -
166,000
8 8 3,240,000
Source
U
"°Ra 234Th 2l0Pb 210PO 21°Bi 222Rn
Totals 91 11 16 8 13 13 13 3,443,000
*The values are in mCi/year and represent averages of acid-leach and
alkaline leach processes.
rt
Values calculated for operating model mills near the end of their expected
life of 20 years.
SOURCE: Adapted from Sears, et al. (1975).
Table 4-7
Estimated Airborne Release Rates of Radionuclides from Model Uranium Mills in New Mexico
and Wyoming
-------
similar (Sears et al., 1975). The length of operating time of a
mill also affects the effluent releases, with the greatest
potential releases occurring near the end of the expected mill
life of 20 years when several million tons of tailings have
accumulated.
Specific figures for airborne release rates of radionuclides from
mines are not readily available. In underground mines, radon is
released from the mine ventilation systems in measurable
quantities, but few reliable measurements are currently
available. In large open-pit mines which have exposed ore bodies
that are porous, relatively dry, and spread over a large surface
area, the 222Rn emanation rates could approach those of mill
tailings systems.
Liquid releases of radionuclides outside the confines of a mill
tailings complex through seepage have been estimated below:
r
Release Rates of Radionuclides to the Ground Water
(From Acid-Leach and Alkaline-Leach Mill Tailings
Values in mCi/year
Process
Acid-leach
Alkaline-leach
Source: Adopted
U 226Ra 23QTh 2*opb 21°
660 51 18,000 51 5
690 7 1 6
from Sears et al. (1975)
A
Seepage
Ponds)
Po 21°Bi
1 51
1 7
4-49
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The values shown in the table are based on using tailings
material for the tailings dam. In this case the assumption was
made that 10 percent of the radionuclides in untreated liquid
waste was lost by seepage from the tailings pond. Other cases
were examined which assumed a combination of careful siting of
the tailings disposal dam, use of earth embankments with clay
cores and treatment of the liquid waste. The assumed loss of
radionuclides for these various combinations was considerably
less, about 0.1 percent of the radionuclides in untreated wastes.
These combinations and assumptions are tabulated by sears et al.
(1975) .
4.4.2
Accidental Releases
Careful design of uranium processing facilities is required to
avoid accidental releases involving radionuclide-bearing
materials. Several systems or processes have the potential for
accidental releases. These include the release of mill tailings
solids or slurry which have the potential for dissemination of
the radionuclides and contamination of affected areas. Failure
of the air cleaning system used in yellowcaJce drying and drumming
may result in release of radioactive materials into the
atmosphere.. Transportation mishaps also may result in localized
yellowcaJce spills. Because of the radioactive nature of these
releases they must have thorough cleanup and decontamination
procedures. The potential for accidental chemical releases
should be considered also. . For example, reagents used in ore
4-50
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processing may escape because of a rupture in a line or by
seepage from a faulty tank.
Operators of uranium mines and mills have the responsibility for
cleaning up and decontamination of affected areas. The plans and
contingency procedures for treatment of spills caused by
accidents need to be coordinated with local and state authorities
that may have their own emergency procedures.
In general, accidental releases occur because of improper design
or operation or as a result of catastrophic events such as fires,
floods, windstorms or earthquakes. Recent tailings spills have
been attributed to inadequate design. Examples of these spills
are:
• Several leaks in a slurry pipeline prevented development
of the tailings beach at the upstream face of the dam.
(The slimes in the beach tend to seal the face and contain
the liquids.) In this instance, the liquids leaked through
the dam.
• A break in a pipe went undetected for several hours during
which time the dam eroded causing a breach and loss of
tailings downstream.
• During the winter months the height of the embankment was
.increased with dirt containing snow and moisture.
Coincident with the onset of milder temperatures the
tailings water was in direct contact with the embankment.
A section of the embankment failed and flooded a portion
of the mill.
Most accidental releases can be prevented by judicious design and
maintenance of safe conditions. However, accidental releases may
occur due to natural events beyond the control of the mine or
4-51
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mill operator. The frequency of occurrence and severity of the
releases can be predicted and analyzed by using probability
statistics and experience from similar operations. Potential
affects of the releases can be evaluated and emergency plans and
procedures prepared.
4.4.3
Biological Effects of Radiation Dose
Estimates of biological effects can be made by predicting or
measuring the radiation dose to populations in areas adjacent to
mine or mill sites and relating the dose to biological effects.
Prediction of dose first requires the collection of quantitative
data on source terms, which describe the quantities and nature of
various radionuclides released through time and the circumstances
of the releases. Second, environmental transport .pathways must
be understood, and quantitative parameters must be used to
describe dispersion, deposition, adsorption, ingestion, and
inhalation. Third, the distribution and retention of various
radionuclides in the tissues of organisms must be understood.
Finally, the dose in units of rads or rems must be calculated
from the tissue concentrations. Dose is usually translated to
expected effects on the basis of the studies (NAS/NRC, 1972)
dealing with the biological effects of ionizing radiation.
Because of the numerous steps involved in calculating dose and
its. variability with time and location, it is important to
validate theoretically predicted doses by periodic sampling of
biota and radiochemical measurement of radionuclides in
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biological tissues. Such validation is possible for operating
mines and mills -and can be used in the adjustments and
modifications necessary in the development of predictive models.
Validated models for a given mine or mill can be used with care
to predict the radiological effects of comparable mines or mills
in similar ecological settings. In this fashion, operational
experience can be used effectively to guide further growth of the
industry in an environmentally acceptable manner.
4.4.4
Control of Radioactive Wastes
Release of radioactive materials in uranium mines and mills can
be controlled by several means. Dust containing radionuclides
from exposed ore, haul roads, and stockpiles can be reduced by
watering or applying chemical stabilizers. Dust and yeliowcake
can be removed from the air in mills by filtering or scrubbing,
and gaseous effluents may be released through stacks to promote
dispersion. Mill floors can be sloped to a sump where spilled
materials can be collected and mill tailings can be. discharged to
a lined impoundment where all liquids are contained.
When operations cease, tailings can be carefully graded and
covered with sufficient overburden and topsoil to reduce radon
release. Seeding and fencing of the area completes the initial
stabilization. Continued irrigation may be required to establish
vegetative growth.
The NRC position is that underground disposal is one of the most
environmentally acceptable means of tailings disposal (NRG,
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Branch Position, May 1977). Underground disposal would eliminate
the problem of erosion and, with sufficient cover, the
radiological hazards. This method may also be cost effective.
Potential problems related to ground water contamination were
previously noted. The NRG is suggesting as an option that
tailings be dewatered to about 20 percent moisture and disposed
into either an open pit or back into an excavation.
4.5
Reclamation, Stabilization and Decommissioning
Most states require reclamation of lands affected by mining,
milling and waste disposal. The objective of reclamation is to
return these lands to their former use or to a more biologically
productive use. Many states require that a reclamation plan be
submitted and approved before a permit to mine or a uranium mill
license is issued. In Wyoming, for example, the plan and
supporting information must satisfy statutes, rules, regulations,
standards and guidelines of the state Environmental Quality Act
of 1973, as amended, the state Land Quality Division Rules and
Regulations of 1975, the Nuclear Regulatory Commission (10
CFR 40) and Regulatory Guide 3.8w In instances where federal
lands are involved, U.S. Geological Survey and U.S. Forest
Service regulations would apply. The scope of a reclamation plan
generally includes decommissioning, stabilization, and
reclamation of the mine and mill site and tailings disposal area
as well as the procedures necessary for establishing plant growth
and restoration of the hydrological features of the site.
Mine reclamation, particularly for open pit mines, is becoming
4-54
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increasingly important in the feasibility, planning and costs of
open—pit mining. Contouring, high—wall elimination and
back—filling requirements are important considerations. State
regulations and interpretations vary greatly. The estimated cost
of reclamation is the basis for a surety bond arrangement to
insure that reclamation and decommissioning are carried out
according to the reclamation plan.
At the present time (1978), the KRC is requiring operators of new
projects to update or change their reclamation and
decommissioning plans, especially for mill tailings management,
as information is developed either from the NEC Generic
Environmental Impact Statement on uranium milling or from new
research.
4.5.1
Reclamation
Planning for reclamation of affected lands begins with an
inventory of the project area soil and overburden, its vegetation
and a determination of the suitability of the soil to support
plant growth. In addition, the water quality and affinity of
wildlife for the vegetative species of the area is also evaluated
(Wyoming Department of Environmental Quality, Land Quality
Division, Guidelines Nos. 1—6, 1976—J 8) . As an example of
reclamation planning, Wyoming requires a pre—mining vegetation
inventory that includes a quantitative estimate of plant
productivity for .evaluating post—mining reclamation. . This
involves various state agencies depending on the proposed
post—mining land use; for instance, state fish and wildlife
4-55
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personnel must be consulted where wildlife habitat is to be
restored.
The topsoil is especially critical to reclamation in arid regions
of the West. In some areas these soils are not well. developed
and not present in sufficient amounts to1 adequately cover the
affected areas. Consequently, overburden may be used with
stockpiled soil in combination with soil conditioners,
fertilizers and chemical stabilizers. The objective of these
additions is to promote retention of moisture and air and to
provide support and nourishment for plant growth.
The re—establishment 'of native grasses, shrubs and forbs is
essential for wildlife habitat, since the grassland and
agricultural crops may not be particularly beneficial to wildlife
in some areas. Recontouring to provide varied terrain also
enhances diverse wildlife populations.
The Soil Conservation Service has prepared recommended seed
mixtures that are best suited to climatic and soil conditions in
different areas, of the ^est; hovever, where overburden is used
without proper conditioning, the overburden may .inhibit
infiltration and result in buildup of clay soils. The clay soils
are not conducive to plant growth and are subject to surface
erosion, which can increase sediment loads into watercourses.
The availability of water is a key factor in reclamation. Water
must be available to supplement the natural rainfall to establish
the initial plant growth. Although irrigation practices vary.
4-56
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once the vegetation is established it can grow without irrigation
within a few seasons.
Reclaimed areas are generally protected from grazing by fencing
for at least two growing seasons to allow the plants to become
established. Release of surety bonds is dependent on this final
step in reclamation.
For an open pit mine and a mill, reclamation may be required for
the following:
• Mine pit
• Overburden and topsoil storage areas
• Ore stockpile areas
• Waste or refuse disposal areas
• Mill tailings impoundment
• Embankments or impoundment basin
• Drainage conduit and control structures
• Shop and mill areas
• Processing areas external to the mill
'j
• Access and haul roads
• Other affected lands
Reclamation of mined areas begins and continues during mining.
Typically, reclamation of the mine pit begins shortly after the
initial stripping operations have been completed and sufficient
ore has been removed to permit backfilling of the overburden into
the pit. The overburden is graded and shaped to permit topsoil
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spreading, seedbed preparation, and seeding at the start of the
next growing season. Some haul roads may be ripped, graded and
prepared as a seedbed for revegetation as the mine pit advances.
Also, as some mill tailings impoundment or disposal areas are
filled to capacity, the liquids are allowed to evaporate and the
failings are stabilized and revegetated. ether areas are
reclaimed using similar procedures at the time the mine and mill
operations cease and the facilities are decommissioned.
The overall cost of reclamation may include the cost of the
following elements; the combination of these costs depends on the
area and project site specifics:
« Topscil and overburden moving and segregation
• Overburden dump shaping
• Topsoil spreading
« Tailings burial
• Settling pond and mill site filling
• Fertilizing
• Seedbed preparation
• Seeding and seed
• Placement of special stabilization materials
• Decommissioning
An ongoing monitoring and maintenance program may not be required
if it can be demonstrated that the reclamation and
decommissioning effort has produced a stable area free from wind
4-58
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and water erosion or other distrubance, and that the radioactive
and toxic materials are sufficiently contained.
4.5.2
Stabilization
A variety of methods may be used to stabilize the topsoil,
overburden or spoil that are stockpiled and used in reclamation
of mined areas. The topsoil can support vegetation quickly,
although irrigation and plant nutrients may be needed to
establish plant growth. Overburden and spoil may be stabilized
by covering with topsoil and by revegetation. The piles are
graded to a slope of less than 3:1 to reduce surface water runoff
erosion.
The mill tailings pose special problems because the waste still
contains 'more than. 85 percent of the total radioactivity that was
present in the original ore. Therefore, stabilization and
reclamation of tailings require special consideration of the
long—term potential hazards of radioactivity and possible
chemical toxicity. While the tailings retention system is
active, surface stabilization is less of a problem because the
sands and 'slimes are covered by liquid except at the tailings
beach. After mill operations are complete, the liquid evapora-ces
and the surface becomes dry. Wind related processes, such as
saltation, can erode the surface, resulting in radioactive
particles being carried away from the impoundment. Covering the
surface with overburden and either rip—rap (rock cover) and/or
vegetation effectively stabilizes the surface; however,
additional measures may be taken to provide protection from
4-59
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radiation, as evidenced by the recent objectives of the NRC and
EPA.
The NRC Branch Position of May 1977 requires the operator to
minimize erosion, radon emanation and direct gamma radiation from
tailings after operations cease. This can be accomplished
through tailings removal and below—grade burial, if justified, or
through a covering with uncontaminated overburden and soil.
Specific performance objectives include:
• Reduction of direct gamma radiation to a level
indistinguishable from background in the area
• Reduction of the radon emanation rate from the tailings
area to a level no greater than twice that of the
surrounding area
• Elimination of the need for an ongoing monitoring and
maintenance program following successful reclamation
• Provision of surety arrangements to assure that sufficient
funds are available to complete the full reclamation plan
It can be shown by calculation that the first performance
objective, reduction of direct gamma radiation, can be achieved
by covering the surface of tailings piles with overburden
material. Cover in excess of 3 feet can be expected to reduce
the gamma radiation levels to nearly background.
Reduction of the radon emanation rate can also be achieved by a
cover of overburden. The magnitude of this reduction is a
function of overburden depth and porosity to gaseous flow. Since
clay is less permeable to gases than coarser materials, it
4-60
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provides a tetter barrier to the flow of gases and liquids. A
clay cap of approximately one-foot-thick covered with 5 1/2 feet
of overburden will reduce radon emanation by a factor of roughly
100 (NEC, NUREG-0129, 1977) which should meet the performance
objective. Without the clay cap, some 15 feet of overburden may
be required to produce the same reduction (Whicker and Johnson,
1978) .
Current design objectives for tailings impoundments provide for
total containment and the control of the release of material into
the environment. Erosion and seepage of solutions are controlled
by dams and by lining the tailings ponds with either bentonite
clay or an artificial liner. Dikes, berm's, and water diversion
channels prevent erosion into natural drainages. Wind erosion is
controlled by keeping the tailings constantly wet or by chemical
stabilization of the edges. Fences control animal access, and
pickett type of drift fences can decrease wind velocities at the
surface. Specific control- measures for tailings impoundments
being installed include covering the tailings with overburden and
soil to a depth of 6 to 15 feet, bulldozing the edges of the
tailings toward the center to reduce the area to be reclaimed;
and revegetating.
Revegetation of tailings impoundments can pose special problems
if the plants create conditions that accelerate the release of
radioactive materials from the tailings. Hendricks (1977) has
postulated that.plants can take up radionuclides through the
roots and release them to the environment or be grazed by animals
that may be eaten by man. Radon may also be released through the
.4-61
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leaves of plants. The alternative to revegetation is to riprap
the surface with rock or otherwise stabilize the tailings
surface. Plants stabilize a soils surface, and since the period
of time in which radioactive releases are a concern is in
thousands of years, stabilizing the tailings surface with
mechanical means is only a short—term solution. Natural
processes of soil formation and plant succession will revegetate
all but the most resistant rock surface in a few hundred years.
Use of tailings impoundment areas after reclamation may be
restricted. At the Bear Creek project. Lucky Me Uranium Mill,
and the Sweetwater Project, the NRC has placed the following
restrictions on the tailings disposal system (NRG, NUREG — 0129,
0295, 0403, 1977):
"1 The holder of possessory interest will not permit the
exposure and release of tailings materials to the
surrounding area.
2 The holder of possessory interest will prohibit erection
of any structures for occupancy by man or animals.
3 Subdivision of the covered surface will be prohibited.
4 No private roads, rails, or rights—of—way may be
established across the covered surface."
More recently, the NRC has proposed burial of tailings in open
pits or excavations to solve the long—term problem of erosion and
radioactive releases. This is in line with the NRC position that
future tailings disposal systems be designed to eliminate the
need for long—term monitoring and care. At present there is no
4-62
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experience with this system of tailings disposal and there has
been no evaulation of potential problems such as transport of
tailings and ground water contamination. Nevertheless, the NRG
and uranium industry are currently evaluating this method for
technical and economic feasibility.
Continued research is leading to a better understanding of
tailings management. Literature dealing with tailings
rehabilitation issues includes Schiager, 1974; Goldsmith, 1976;
Bernhardt, Johns and Kaufmann, 1975; Kaufman, Eadie and Russell,
1976; Scarano, 1977; Ford, Bacon and Davis Utah Inc., 1977.
4.5.3
Decommissioning
The NEC requires a decommissioning plan, including estimated
costs and surety arrangements at the beginning of a project. A
more detailed plan is required near the end of the useful life of
the project (NRG, NUREG-0403, December 1977). The plan for a
mill may include:
• Decontamination of the processing facilities
• Disposal of fuels and chemicals
• Dismantling and removal of buildings and structures (power
lines)
• Burial of foundations
• Covering of buried materials, grading, covering with
topsoil and revegetating
4-63
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In some cases selected buildings, structures, roads, wells and
flood control ponds may be left for future use by the land owner.
The mill site area will be contoured, layered with topsoil and
also revegetated. Radiation surveys may be conducted to
demonstrate that levels of radioactivity are within prescribed
limits and that the decontamination procedures were successful.
4.6
Monitoring and Surveillance Programs
Federal and state agencies require that monitoring programs be
designed and approved before any significant development
activities begin and that these programs continue during
operations. After operations cease and reclamation procedures
are complete, surveillance of the project site may be required to
measure the success of reclamation and to demonstrate that the
requirements of the performance bond have been met. As noted in
Section 3.5, NRG performance objectives include elimination of
ongoing monitoring and maintenance following successful
reclamation.
Preoperational and operational monitoring programs are conducted
to predict and evaluate the impact of mine and mill operations.
The major elements of the monitoring programs include:
• Establishing sampling procedures, frequencies, material to
be collected, and types of analyses
• Maintaining accurate records in an accessible form,
including the traceability of samples
•• Analyzing and interpreting data
•• Periodically reviewing the results and updating programs
4-64
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NRC prescribes monitoring requirements in non—agreement states,
and agreement states pattern their programs after the following:
• NRC Regulatory Guide 3.8, Preparation of Environmental
Reports For Uranium Mills (1973)
• NRC Regulatory Guide 4.14, Measuring, Evaluating, and
Reporting Radioactivity in Releases of Radioactive
Materials in Liquid and Airborne Effluents From Uranium
Mills. Distributed for comment, June 1977.
• "Branch Position For Preoperational Radiological
Environmental Monitoring Programs For Uranium Mills"
(1978)
• "Proposed Branch Position For Operational Radiological
Environmental Monitoring Programs For Uranium. Mills"
(1978)
V
The sampling parameters needed to satisfy the non-radiological
aspects of a uranium project are usually similar to any other
mining project. Sampling for radionuclides is conducted either
on a more frequent or continuous basis.
4.6.1
Preoperational Monitoring
The objective of preoperational monitor .ing is to measure the
characteristics of the site prior to mining or mill construction
activities. The impact from these activities may be predicted
using modeling techniques and site measurements. These data also
serve as a reference for monitoring the impacts that result from
construction and operation.
4-65
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Section 6.0, Effluent and Environmental Measurements and
Monitoring Programs, of NRC Regulatory Guide 3.8, sets forth
objectives and information needs for the applicants
preoperational program for each of the following:
SURFACE WATERS
GROUND WATER
Physical and chemical parameters
Models
AIR
Meteorology
Models
LAND
Geology and soils
Land use and demographic surveys
Ecological parameters
RADIOLOGICAL SURVEYS
The radiological surveys are not classified further in the
Guide, but they may include:
External gamma radiation
Radionuclides in soils
Radioactivity analyses of water
Biological radioactivity
Airborne radioactive dust
Radon in air
4-66
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Instrumentation, scheduling, techniques and procedures are
emphasized in Section 6.0 of Regulatory Guide 3.8.
The NEC Branch Position for preoperational radiological
environmental monitoring programs specifies the need for data on
background radionuclide concentrations and radiation dose rates
at the mill site and vicinity prior to operations. The data is
required for:
• Assessing radiological impacts of the future milling
operations
• Determining compliance with applicable environmental
standards
• Base line reference data at time of site decommissioning
The data from the program may include many of the components
listed in the example program illustrated in the NRC Branch
Position. In general, the sampling media, the frequency of
sampling, and types of analyses performed will be continued
during operational monitoring. Typically, preoperational
monitoring begins one year before milling operations start.
Similarly, this type of monitoring is conducted prior to mining.
4-67
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4.6.2
Operational Monitoring
The elements of the operational program also set forth in
Section 6.0 of NRC Regulatory Guide 3.8 are:
Mill-effluent monitoring
Environmental Radiological Monitoring
Chemical effluent monitoring
Meteorological monitoring
Ecological monitoring.
In the case where the proposed project includes a uranium mine, a
mine and mill effluent monitoring program is required. An
example of an operational monitoring program is shown in
Table 4—8. This example is a- proposed program fo.r the Sweetwater
Uranium Project, and therefore it may be modified somewhat by the
time it is finally approved by NRC. The environmental elements
and materials sampled include all of the five elements cited in
the Regulatory Guide 3.8.
After the applicant submitted the program, the NRC issued a
proposed Branch Position For Operational Radiological
Environmental Monitoring Programs For Uranium Mills (NRC,
Proposed Branch Position, 1978) . The NRC has formally defined
the measurement data needs for radiation dose rates and
radionuclide concentrations in the mill site environs.
4-68
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Environmental Element
4 Mutorial Sanolfd
Aabient Air
Suspended particles
Clean air
Effluent Air
Ground Vater
Monitor wells
Monitor wells
Tailings Liquid
Aabient Radiation
Direct external
arpoaura
Mine Devatericg
Discharge
Topsoil
Biota
Vegntation
Chemical parameters to
operations of the mill
s™.
Location
6 Locations, at least
3 downwind of the site
6 Locations, at least
3 downwind of the site
Tellovcake drier
and packaging stacks
All mill stacks
Roof vents, a-x bldg.
U-6 Locations near
tailings inpoundment
^-6 Locations near
mining & mill aitas,
including potable
water supply
Tailings pond
6 Locations
(soae as ambient air
stations)
Settling ponds outlet
6 Locations
6 Locations
(Sane aa soil)
be analyzed for will be
have bogun.
lii« Pro?™
Method
High voiuno
air saaplor
GRAB
0.5-2 L/min
for 1 week
Representative
GRAB
Representative
GRAB
GRAB
GRAB
GRAB
Thernc—
luminescent
dosiaeters •
GRAB
GRAB
(C-a»)
GRA3
dotorainetl froa
Fr«au»n~v
Continuous
Monthly
(1 week con-
tinuous per
month)
Seai-annually
Quarterly
Seai-annually
Annually
First year:
aonthly,
quarterly
Following yrs:
quarterly,
annually
First year:
quarterly,
annually
Following yrs:
semi-annually,
annually
Annually
Continuously
Per NFDES
Perait
Annually
Annually
Soople
Analysis
rr^uencv
Quarterly
(composite)
Monthly
Seai-annually
Quarterly
Semi-annually
Annually
Monthly
Quarterly
Quarterly
Annually
Quarterly
Annually
Seai-annually
Annually
Annually
Quarterly
Per NFDES
Perait
Annually
.Annually
an analysis of samples taken from
1
Isotope, Radiation, or
Chenicnl Identified
Total suspended particles,
0-nat, Ra-226, Th-230, and
Pb-210
Rn-222
Rn-222
Th-230, Ra-226
0-nat
0-nat, Total suspended
parti culates
Total hydrocarbons, NH
0-nat, Ra-226
Th-230, Pb-210, chenicals
U-nat, Ra-226
Th-230, Pb-210, chemicals"
0-nat, Ra-226
Th-230, Pb-210, chemicals*
U-nat, Ra-2S6
Pb-210, Th-230, cheaicala*
Pb-210, U-oat, Ra-226
Th-230, pH
Gaaoa, Beta
Per NPDZS Permit
(see Appendix D)
U-nat, Ra-226, Th-230
Pb-210, Gross
U-nat, Ra-226, Th-230
Pb-210
the tailings pond once
SOURC2I NRC, DES, NURBG-Oll03, Docomber 1977.
Table 4-8
Operational Monitoring Program
4-69
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"These measurement data are needed:
To demonstrate or confirm compliance with applicable
environmental radiation standards and regulations, e.g.,
10 CFR 20, "Standards for Protection Against Radiation"
and 40 CFR 190, "Environmental Radiation Protection
Standards for Nuclear Power Operations (EPA Uranium Fuel
Cycle Standards)." Section 20.201 of 10 CFR 20 entitled
"Surveys" requires that a licensee conduct such surveys of
concentrations of radioactive materials as may be
necessary to demonstrate compliance with the regulations.
For use by the NRG staff in evaluating the environmental
impact of the radioactive effluents from the milling
operations including estimates of the potential radiation
doses to the public.
For evaluation by the NRC staff of the adequacy and
performance of effluent control systems and procedures,
including tailings retention systems."
The NRC stresses effluent measurements off-site rather than at
the point of release because of the difficulty of taking direct
measurements for sources such as tailings piles and ore storage
pads. The NRC lists several essential program elements: air,
water soil, and vegetation or forage sampling, and direct
radiation measurements.
• AIR SAMPLING - Ambient air quality is sampled because of
the potential radiological hazard from airborne ore,
yellowcake and dusts as well as radon gas generated from
radium contained in tailings.
• WATER SAMPLING - Water is sampled because several of the
radionuclides in the tailings may be leached and leave the
site by ground water or surface water movement.
Ground water must be collected from sampling wells located
down gradient around the designated "tailings disposal
area. Hydrological data are used to place these wells in
the predominant flow direction away from the site. A
control well is located upgradient above the tailings site
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disposal area. Drinking water or livestock well water is
also sampled.
Surface water must be collected from large water
impoundments near the mill site that may be subject to
surface drainage or influenced by seepage from the
tailings site. Samples of surface water are also
collected upstream and downstream of the mill site.
• SOIL SAMPLING - Surface soil samples are taken as a
measure of area radioactivity contamination due to site
operations. Contamination could result from airborne
dispersion or transport due to liquid effluents or runoff.
These samples are taken at the same locations for air
particulate samples.
• VEGETATION OR FORAGE SAMPLING - Samples of plants that
serve as forage for local wildlife or livestock are
important to collect for two reasons. First, since plants
generally have large surface areas, they are collectors of
radioactive contamination resulting from the operation.
Secondly, plants are part of terrestrial food pathways to
wildlife, livestock and eventually to humans.
The sampling is considered necessary if dose calculations
show that ingestion of meat from these grazing animals
constitute a potentially important exposure pathway.
DIRECT RADIATION MEASUREMENTS - Gamma rays from
radionuclides are measured at the same locations as air
particulate samples to obtain gamma dose rates.
The specific number, frequency and type of analyses required for
each of the program elements are outlined in NRC's proposed
Branch Position. Although the NRC position is not final, each
program element is reviewed on a site—specific basis, and final
approval of these is documented in the Final Environmental Impact
Statement for the proposed project.
4-71
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4.6.3
Post-Reclamation Surveillance
Surveillance is necessary to determine that reclamation has been
successful. Revegetation is necessary to restore productivity
and to meet surety requirements. stabilized areas should be
periodically checked, particularly if there is a potential
radiological or chemical hazard.
Radiological and chemical surveillance should continue until it
is determined that no significant release of material is
probable. The tailings impoundment design, the reclamation
procedures, and the type of stabilization of any other material
produced or stored onsite will determine the extent and duration
of the surveillance program.
»
For instance, surveillance and monitoring activities may be more
frequent at first and then diminish as the land and reclamation
adjust to normal cycles. If no change in the project site is
detected after a period of time, usually 5 to 25 years, then
inspection of the area will only be necessary on a long-term
basis.
The . long—term institutional controls that govern the use of the
project site or use of materials from the site have yet to be
established. In the past, tailings were used as fill in the
construction of residences. Radon emanating from the tailings
was trapped in the dwellings resulting in a radiological health
hazard to the occupants due to inhalation of radon and its
daughters. An expensive remedial program was required to remove
the tailings from under the homes. The questions of who has
4-72
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title to project lands after mining and milling has ceased and of
how to provide'continued protection of the public are unresolved
and r,emain the subject of regulatory agency review and public
comment.
Two reports which address the problems of long term controls are
the EPA Background Report, Considerations of Environmental
Protection Criteria for Radioactive Waste, February 1978, and the
report by the Western Interstate Nuclear Eoard Committee on
Mining and Milling of Nuclear Fuels, Policy Recommendations on
Financing Stabilization, Perpetual Surveillance and Maintenance
of Uranium Mill Tailings, April 1977.
4-73
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CHAPTER 4
References
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of Maximum Acceleration in Rock in the Contiguous United States.
U.S.. Geol. Survey Open-File Report 76—416. Washington, D.C.:
U.S. Government Printing Office, 1976. .
Bernhardt, D.E., F.B. Johns and R.F. Kaufmann. Radon Exhalation
from Uranium Mill Tailings Piles, Description and Verification of
the Measurement Method. Technical Note CRP/LV—75—7(A). Las
Vegas, Nevada: U.S. Environmental Protection Agency, 1975.
Blanchard, R.L. Relationship Between 21QPo and ziopb jn Man and
His Environment. In B.. Aberg and F.P. Hungate (eds.).
Radiological Concentration Processes. New York: Pergamon Press,
1967.
Cannon, H.L. "The Effect of Uranium Vanadium Deposits on the
Vegetation of the Colorado Plateau." Am. J. Science 250:735-770,
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Coffman, Jerry L., and Carl A. von Hake. Earthquake History of
the United States. Publication 41—1. . Washington, D.C.: U.S.
Government Printing Office, 1973.
Eisenbud, M. Environmental Radioactivity (2nd ed.). New York:
Academic Press, 1973.
Englemann, R.J. and G.A. Sehmel. Atmosphere-Surface Exchange
(1974). ERDA Symposium Series 38. CONF-740921. Springfield,
Virginia: National Tech Inf. Service, 1976.
Environment Reporter. Current Developments, Volume 8, No. 41,
Washington, D.C.: .Bureau of National Affairs, February 10, 1978.
Environmental Protection Agency. Assessment of. Environmental
Aspects of Uranium Mining and Milling. EPA 600/7—76—036, 1976.
. Radiological Quality of the Environment in the United
States. EPA 520/1-77-009, 1977.
Evans, R.D.."The Radium Standard for Bone Seekers: Evaluation of
the Data on Radium Patients and Dial Pointers." Health
Physics 13:267-278, 1967.
. "Engineer's Guide to the Elementary Behavior of Radon
Daughters." Health Physics 17:229-252, 1967.
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Finkel, A.J., C.E. Miller and R.J. Hasterlik. Radium Induced
Malignant Tumors in Man. In C.W. Mays et al. (eds.). Delayed
Effects of Bone-seeking Radionuclides. Salt Lake City, Utah:
University of Utah Press, 1969.
Ford, Bacon and Davis, Utah Inc. Phase II—Title I Engineering
Assessment of_ Inactive Uranium Mill Tailings. GJT—3: Mexican Hat
Site, Mexican Hat, Utah. Grand Junction, Colorado: U.S.
Department of Energy, 1977.
Garner, R.J. Transfer of Radioactive Materials from the
Terrestrial Environment to Animals and Man. Cleveland: CRC
Press, 1972.
Goldsmith, W.A. "Radiological Aspects of Inactive Uranium Milling
Sites: an Overview." Nuclear Safety 17(6), 1976.
Gopal-Aysngar, A.R. and K.B. Mistry. On Radioactivity of Plants
from the High Radiation Areas of the Kerala Coast and Adjoining
Regions. In Radioisotopes in Soil—Plant Nutrition Studies.
Vienna: International Atomic Energy Agency, 1962.
Healy, J.W. and J-.J. . Fuguay. Wind Pickup of Radioactive
Particles from the Ground. Vol. 18. Proceedings of the Second
United Nations International Conference on the Peaceful Uses of
Atomic Energy, Geneva, Switzerland. New York: United Nations and'
IAEA, 1958.
Hendricks, D.W. Uranium Mill Tailings Storage, Use, and Disposal
Problems. Paper presented at the University of -Nevada Conference
on Uranium Mining Technology, Reno, Nevada, April 28, 1977.
Hill, C.R. "Lead-210 and Polonium-210 in Grass". Nature 187:211,
1960.
Hine, G.J. and G.L. Brownell. Radiation Dosimetry. New York:
Academic Press, 1956.
International Atomic Energy Agency. (IAEA). Effects of Ionizing
Radiation on• Aquatic Organisms and Ecosystems. Tech. Rept.
Series 1972. Vienna: International Atomic Energy Agency, 1976.
International Committee on Radiation Protection (ICRP). "Report
of Committee II on Permissible Dose for Internal Radiation."
Health Physics 3:1-233, 1960.
Kaufman, R.F., G.G. Eade and C.R. Russell. "Effects of Uranium
Mining and Milling on Ground Water in the Grants Mineral Belt,
New Mexico." Ground Water 5(5), 1976.
Kraner, H.W., G.L. Schroeder, and R.D. Evans. Measurements of
the Effects of Atmospheric Variables on Radon 222 Flux and
Soil—Gas Concentrations. In J.A.S. Adams and W.M. Lowder (eds.)
The Natural Radiation Environment. Chicago: University of
Chicago Press, 1964.
4-75
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Meeks, A.T. et al. Assessment of Environmental Aspects of Uranium
Mining and Milling. Columbus, Ohio: Eattelle Columbus
Laboratories, 1976.
Mills, M.T., R.C. Dahlman, and J.S. Olson. Ground Level Air
Concentrations of Dust Particles Downwind from a Tailings Area
During a Typical Windstorm. ORNL—TM—4375. Oak Ridge, Tennessee:
Oak Ridge National Laboratory, 1974.
Morgan, K.Z. and J.E. Turner. Principles of Radiation
Protection. New York: John Wiley & Sons, Inc., 1967.
National Academy of Sciences (NAS). Radionuclides in Foods.
Washington, D.C.: National Academy of Sciences, 1973.
National Academy of Sciences/National Research Council (NAS/NRC).
The Effects on Populations of Exposure to Low Levels of Ionizing
Radiation. Report of the advisory committee on the biological
effects of ionizing radiations. Div. of Med. Science.
Washington, D.C.: National Academy of Science/National Research
Council, 1972.
National Council on Environmental Radiation Measurements.
Environmental Radiation Protection and Measurements. NCRP Report
No. 50. Washington, D.C.: National Council on Radiation
Protection and Measurements, 1976.
National Oceanic and Atmospheric Administration (NOAA).
Earthquake History of the United States. U.S. Dept. of Commerce
Publication 41-1, 1973.
Nuclear Regulatory Commission. Draft Environmental Statement
Related to Operation of Moab Uranium Mill, Atlas Minerals
Division, Altas Corporation. NUREG—0341, November 1977.
. Draft Environmental Statement Related to Operation of
Morton Ranch Mill, United Nuclear Corporation. NUREG-0439,
April 1978. •
. Draft Environmental Statement Related to Operation of
Sweetwarer Uranium Prelect, Minerals Exploration Company.
NUREG-0403, December 1977.
. Draft Environmental Statement Related to Operation of
Bear Creek Project, Rocky Mountain Energy Coir.pany. NUREG—0129,
January 1977.
Draft Environmental Statement Related to Operation of
Lucky Me Uranium Mill, Utah International Inc. (Lucky Me Uranium
Corporation). NUREG-0295, June 1977.
. Final Task Force Report on the Agreement States
Program. NUREG—0388, December 1977.
4-76
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. Standard Format and Content of license Applications
for Uranium Mills. Regulatory Guide 3.5 (Revision 1), November
1977.
. Branch Position: Uranium Mill Tailings Management.
Fuel Processing and Fabrication Branch, May 13, 1977.
Osburn, W.S. "Primordial Radionuclides: Their Distribution,
Movement:, and Possible Effect Within Terrestrial Ecosystems."
Health Phys. 11:1275-1295, 1965.
Polikarpov, G.G. Radioecology of Aquatic Organisms. New York:
Reinhold Book Div., 1966.
Rocky Mountain Energy. Environmenta1 Report, Bear Creek Project,
Converse C_ounty_, Wyoming, for Rocky Mountain Energy. Denver,
Colorado: Rocky Mountain Energy Company, 1975.
Russell, R.S. and K.A. Smith. Naturally Occurring Radioactive
Substances: the Uranium and Thorium Series. In R.S. Russell
(ed.). Radio-Activity and Human Diet. New York: Pergamon Press,
1966.
Scarano, R.A. Current Uranium Mill Licensing Issues. In Harward,
E.D. (ed.). Workshops on Methods for Measuring Radiation in and
Around Uranium Mills. Washington D.C. : Atomic Industrial Forum,
Inc., .1977.
Schiager, K.J. "Analysis of Exposures on or Near Uranium Mill
Tailings Piles."_ Rad. Data and Reports 15:411-425, 1974.
Sears, M.B. et al. Correlation of Radioactive Waste Treatment
Costs and the Environmental Impact of Waste Effluents in the
Nuclear Fuel Cycle for Use in Establishing "As Low As Practical"
Guides - Milling of. Uranium Ores. Vol. 1. ORNL/TM-4903. Oak
Ridge, Tenn: Cak Ridge National Laboratory, 1975.
Skidmore, E.L. A Wind Erosion Equation: Development, Application,
and Limitations. In Atmosphere—surface Exchange of Particulate
and Gaseous Pollutants. CONF-740921 1974. Springfield, Va:
National Tech, Information Service, 1976.
Slade, D.H. (ed.). Meteorology and Atomic Energy 1968.
TID-24190. Springfield, Va: National Bureau of Standards, 1968.
Smith, M. Recommended Guide for the Prediction of the Dispersion
of Airborne Effluents. New York: American Society of Mechanical
Engineers, 1968.
Tanner, A.B.' Radon Migration in the Ground: A Review. In J.A.S.
Adams and W.M. Lowder (eds.) The Natural Radiation Environment.
Chicago: University of Chicago Press, 1964.
4-77
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Turner, D.B. Workbook of Atmospheric Dispersion Estimates.
Cincinnati, Ohio: National Air Pollution Control Administration,
1970.
United Nations Scientific Committee on the Effects of Atomic
Radiation (UNSCEAR). Ionizing Radiation: Levels and Effects.
New York: United Nations, 1.972.
U.S. Government Manual. Washington, D.C.: U.S. Government
Printing Office, 1977-78.
Whicker, F.W. and L. Fraley, Jr. Effects of_ Ionizing Radiation on
Terrestrial Plant Communities. In J.I. Lett, H. Adler, and M.R.
Zelle (eds.). Advances in Radiation Biology. Vol. 4. New York:
Academic Press, Inc., 1974.
Whicker, F.W. and J.E. Johnson. "Preliminary Draft for Comment:
Radiological Considerations for Siting, Operation and
Decommissioning of Uranium Mines and Mills." Fort Collins,
Colorado, February 1978.
Wyoming. Department of Environmental Quality. Land Quality
Division. Guidelines Nos. 1—6. Cheyenne, Wyoming, 1976—1978.
4-78
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CHAPTER 4
Appendix
This appendix contains discussions of the following topics
• radionuclides of the uranium decay series
• radionuclide transport and exposure pathways
• prediction of radiation dose
• radiation dose rates and their significance
Also included are tables that summarize estimated dose rates from
background sources of radioactivity and from uranium mills.
A-1
Radionuclides of the Uranium Decay Series
The radionuclides extracted from uranium ore are fissile 2 3 so and
fertile 23aU. Some 99.28 percent of natural uranium is 238U,
while only 0.72 percent is 23SU. The potential radiation
contamination from uranium mining and milling arises not so much
from the uranium itself, but from the radionuclides generated by
its decay. . Natural uranium exists in the earth's crust because
of the long half— lives of the principal uranium isotopes. The
physical half— life of 23«U is 4.5 billion years, and that of 235jj
is 0.7 billion years. The radioactive decay of 23sy and 23au
generates shorter-lived daughter products at an essentially
constant rate as measured in terms of human experience. Although
both 23SU and zaag generate a series of radioactive products, the
chain is discussed due to the abundance of 238U.
The . 23aU series includes 13 principal radionuclides in addition
to the primordial parent (see Figure A— 1) . The series terminates
with the formation of stable 206Pb. Secular equilibrium of 23«u
4A-1
-------
3.1 m:
238
U
4.5xl09 yr
234
Tli
218
Ln
i
Po
3.8 day
222
Rn
24 day
ft.y
_ 1.6xl03 yr
234
Pa
1 . 2 mi n
234
U
a
>
226
Ra
8x10 A yr
2.5x]05 yr
I
230
Th
a
i
214
Pb
27 min y
Ay
214
Bi
20 min x
ft.y
214
Po
1.6x10 A sec ^
210
Pb
r
206
Pb
138 day
210
Po
5 day
21 yr
r
210
Bi
Stable
SOURCE: Whicker and Johnson, 1978
figure A-l
The Primary Decay Series of Uranium - 238
Note: Half lives and major types of
radiation are shown. Alternate,
less frequent branching decays
are not shown.
-------
and daughters is usually assumed for geological deposits, which
means that daughter and parent activities, expressed as curies,
or disintegrations per unit time, are equal. Chemical, physical
and biological processes can act upon a sample of ore to cause
chemical separation of some members of the uranium decay series,
disrupting secular equilibrium.
During milling, about 85—95 percent of the uranium is recovered
from the ore as uranium oxide (yellowcake). The mill tailings,
therefore, are depleted in the uranium isotopes. They are also
soon depleted in 234Th and 23*Pa as well, because these nuclides
are being produced at a much reduced rate and the amounts present
decay in a matter of months to innocuous levels, owing to their
short half—lives. However, long—lived 230Th maintains the chain
of radionuclides from 226Ra through 210Po.
In tailings, however, several complications can arise. For
instance, 22*Ra and 230Th may separate to some extent, disrupting
secular equilibrium between the two radionuclides. In addition,
gaseous 222Rn can escape from the tailings, quite rapidly in some
cases, to form a partial discontinuity in the secular equilibrium
of the decay chain. The degree of this discontinuity is
dependent upon the rate at which radon can diffuse away from its
source, 226Ra. If diffusion is very poor, essentially all the
222Rn will decay in place, and secular equilibrium is likely to
be maintained through 206Pb. If a large fraction of the 222Rn
atoms diffuse from the tailings to the atmosphere, the daughter
nuclides of radon will show reduced activity levels in the
tailings with respect to 226Ra.
Calculation shows that a curie of 226Ra will produce a curie of
222Rn every 5.5 days, or 0.18 Ci/day. A most important objective
of tailings management is to reduce the escape of radon to the
atmosphere because it usually produces a greater radiation dose
to humans, plants, and animals around a mill than any other
process.
The most commonly monitored radionuciides occurring around mill
tailings include 23<>Th, 22*Ra, 222Rn, and 210Pb. Thorium-230 is
a long—lived alpha emitter that lodges primarily in bone if
assimilated. Fortunately, because of its low solubility 23°Th is
not readily taken up by plants or assimilated by animals.
However, it can enter the body through inhalation and become a
more significant hazard than other radionuclides in mill tailings
dust (ICRP, 1960).
Radium—226 generally poses a greater ingestion hazard than 230Th
because it forms more soluble compounds and behaves chemically in
a manner similar to calcium, an essential nutrient element. It
is therefore assimilated by both plants and animals. Radium—226,
an alpha emitter, lodges tightly in the bone matrix, and in
sufficient levels, it has produced bone cancer in humans
(Evans, 1967; Finkel, Miller and Hasterlik, 1969). Overall,
226Ra is of more concern than the other, radionuclides in mill
tailings from the standpoint of food-chain transport processes.
4A-3
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Radon—222 can pose perhaps the greatest biological risk around
uranium mines and mills because it can be released into the
atmosphere in large quantities from exposed ore or tailings, and
its decay produces a series of seven radionuclides which can be
inhaled or enter food chains. These daughter products of 222Rn
generally produce a much greater health risk than does _radon
itself. The reason for this is that radon is a noble gas and is
not easily absorbed or adsorbed by biological surfaces.
Lead—210 is long—lived and has some potential -co accumulate in or
on biological tissues. It is also a bone seeker with an
intermediate tendency to be assimilated. Levels of several other
radionuclides, such as 213Po, 2143i and 210Po, can sometimes be
inferred from measurements of 222Rn and 2*opb (Evans, 1967).
A substantial body of information exists about the levels of
radionuclides in ore and mill tailings and on the quantities
which can be released to the environment (Sears, et al., 1975).
There is much less data, however, on the behavior of these
radionuclides once they enter ecological systems.
A-2
Radionuclide Transport and Exposure Pathways
Ionizing radiation emitted from the radionuclides associated with
uranium mining and milling impact bioicjgical populations in two
ways. One- is by internal irradiation from radionuclides
deposited within tissues, and the other is by external
irradiation from radionuclides that are near but external to the
exposed biological tissues. The radiation dose received is
therefore highly dependent upon the amounts of radioactive
material -chat enter the organism as well as the amounts -hat
reside in the immediate environment. In order to predict these
amounts, the environmental transport pathways must be understood
and quantified.
Two routes of radionuclide transport involve aquatic and
terrestrial systems. Transport between these systems is possible
through erosion, irrigation, and aerial deposition. As
indicated, mine—mill effluents reach the terrestrial environment
mainly through erosion of radionuclide-bearing particles of ore,
tailings or yellowcake, and through emanation of gaseous 222Rn
from ore and tailings. Aquatic systems receive radionuclides by
surface runoff, seepage into the ground water, aerial deposition,
and erosion of contaminated soil. Ground water may appear on the
surface through wells, springs, or a rising water table
associated with topographic depressions or increased hydrostatic
pressure.
Radionuclides in the atmosphere are subject to dispersion,
directional transport, deposition, and inhalation. Dispersion
and transport are determined by meteorological factors such as
wind speed, direction, and turbulence, and by precipitation.
4A-4
-------
Deposition by gravitation forces, impaction, and rainout or
washout (Slade, 1968) results in the contamination of soil,
vegetation and surface water. The smaller (<10 microns) aerosol
particles may be inhaled by animals and man. Material which has
been deposited on the soil can become resuspended by wind and
other kinds of physical disturbance. This material thus becomes
subject to further dispersal and deposition at a distant
location.
Radioactive materials in surface waters are subject to complex
processes involving dispersion, physical transport and absorption
and/or adsorption by sedimentary material, aquatic plants and
animals. Surface waters may be applied to the land for
irrigation purposes or consumed by humans and wildlife.
Dispersion and transport is determined by the nature of the
hydrological system and the sediments and aquatic biota.
Absorption and desorption processes are complex, depending upon
physical, chemical and biological factors.
Populations contaminated with radioactivity are of concern for
three major reasons. First, radionuclides incorporated into
living tissues are subject to food chain transport and may reach
man. Second, radioactive material may be spread from a site of
contamination by movements of plants and animals. Third, the
radioactivity may have a detrimental effect upon the organism
itself. Food chain transport of radionuclides in terrestrial
ecosystems involves ingestion of contaminated plant or animal
tissues and assimilation and incorporation of 'the material.
Terrestrial food chain transport to man largely involves
consumption of crops and domestic animal products, although
wildlife species are also consumed by a fraction of the
population. Aquatic food-chain-derived material can reach man
through consumption of fish and waterfowl. As mentioned
previously, food chain transport involves chemical and
physiological processes and there is discrimination at biological
membranes. Of the elements involved in the uranium series,
radium is most readily assimilated by most organisms. Lead and
polonium are intermediate in their level of absorption by
organisms.
External exposures to organisms from radionuclides in the
environment arise principally from gamma rays and secondarily
from beta particles. In most ecosystems the soil is usually the
predominant reservoir of radioactivity. Thus, the decay of
gamma—emitting radionuclides in soil normally accounts for a
large fraction of the external exposure received by plants and
animals.
4A-5
-------
A-3
Prediction of Radiation Dose
Prediction of radiation dose to organisms from environmental
releases of radioactive materials is extremely complex, yet such
predictions are required for environmental reports and impact
statements. The steps in the predictive process include:
determination of source terms; atmospheric and aqueous dispersion
and deposition; absorption and uptake by plants; ingestion and
inhalation by animals and man; retention and distribution of
radionuclides in the body; concentrations in critical organs; and
finally, calculation of dose. Each step can involve complex
equations with numerous parameters in each. Very few of the
parameters are constant over the wide range of circumstances
encountered at uranium mines and mills. Because of these
complexities, there is usually a considerable degree of
uncertainty associated with dose prediction. Predictive models
are still being developed.
Source terms are usually predicted from actual measurements at
operating facilities or from theoretical calculations. Emanation
rates of radon can be estimated on the basis of theoretical
models (Kraner et al., 1964; Tanner, 1964) and/or empirical
relationships (Schiager, 1974). Rates of particulate suspension
by wind can also be estimated in some cases from the literature.
Helpful references include Healy and Fuquay (1958); Mills,
Dahlman and Olson (1974); and several papers in the volume edited
by Englemann and Sehmel (1976). The problems of estimating
seepage of radibnuclide-bearing liquids into the ground and
subsequent migration of the material are discussed by Sears
et al. (1975) .
Atmospheric dispersion estimates have almost exclusively employed
Gaussian plume models with minor modifications to these models.
More recent modifications and applications are presented by Slade
(1968), Smith (1968), and Turner (1970). The purpose of -he
dispersion calculations is to predict the concentrations of
radionuclides in air at specific locations relative to a given
source. With appropriate meteorological data,, atmospheric
dispersion calculations can be applied with reasonable precision
at all sites, excepting -chose in complex, rugged terrain.
Estimating dispersion of radionuclides in surface waters depends
on mixing, turbulence and flow. These are site-specific and
depend upon the geometry and nature of the channel or basin.
Radionuclides in water are most likely to enter the food chain by
direct ingestion or sorption by aquatic organisms. In the case
of direct ingestion, the relationships between water
concentrations, human body burdens, and radiation doses are
thoroughly tabulated in ICRP (1960). Limited data on the
relationships between water concentrations of naturally occurring
radionuclides and concentrations in the tissues of aquatic
organisms are available (Polikarpov, 1966; IAEA, 1976). Such
data can be applied with caution to aquatic ecosystems in
4A-6
-------
general, so long as the magnitudes of uncertainty and -their
causes are understood.
Passage of the naturally occurring radionuclides through food
chains also involves many complexities. Some helpful
publications are available for radiological impact assessment.
Some of the basic models which permit the calculation of tissue
burdens from intake and retention data are outlined in ICRP
(1960). Such models are applicable to plants, animals and
humans, providing the appropriate kinds of parameters and
accurate parameter values can be located. While there is
generally a lack of information on parameters appropriate to
organisms around uranium mines and mills, useful data includes
Osburn, 1965; Russell and Smith, 1966; NAS, 1973; Eisenbud, 1973;
Cannon, 1952; Gopal-Ayengar, 1962; Garner, 1972; Hill, 1960; and
Slanchard, 1967.
When concentrations of radionuclides in the biological tissues
have been calculated, the resulting radiation' dose may be
calculated. Cose, measured in rads or preferably dose equivalent
measured in rems, is the common denominator used to describe the
effective amount of radiation energy absorbed by critical
tissues. These dose units are used as the fundamental predictors
of biological damage or risk. Doses received by various
internally deposited radionuclides, as well as those from
external irradiation, can be summed in order to estimate total
dose. Doses are expressed as a rate (that is, rads/year;
rams/year) or as a time-integrated dose commitment (that is, rads
or rems). Methods of calculating dose are outlined in several
publications (ICRP, 1960; Kine and Browneli, 1956; and Morgan and
Turner, 1967).
A-4
Radiation Dose Rates and their Significance
The radiological impact of uranium mining and milling is measured
by the radiation doses received by populations. The calculated
dose is proportional to the concentration of radioactivity and
the average residence time of the radioactivity in biological
tissue. This dose is termed "dose commitment" or the total dose
integrated over the life time of the organism.
Radiation dose rates and dose commitments calculated for all
non—human segments of the ecosystem are normally averages for the
populations involved, while those calculated for humans are worst
possible cases for the individuals involved. This practice is
followed because concern for human risk is expressed in relation
to individuals and is much more conservative than concern
expressed at the population level. The proper dose unit is a
multiple of the rem, which is often also termed the dose
equivalent. If human population doses are calculated, the proper
unit is man—rems. This is the average dose to the human
population at risk multiplied by the total number in the
4A-7
-------
population. Expressed this way the value has relevance to the
risk of genetic and somatic effects which can only be evidenced in
populations.
Direct external radiation doses to humans are by gamma—rays from
radionuclides i_n mill tailings or contaminated local soils.
Estimates of radiation exposure rates from radionucliaas
uniformly distributed in soil are provided in Table A—1.
Gamma—ray radiation doses are significant for the whole—body
and/or tne gonads and may be calculated easily from the measured
exposure rates (X) as:
DOSE RATE ( ^L ) = 0.87 X ( -^
Sears et al. (1975) measured exposure rates over several tailings
piles and found the values to average close to 900 microroentgens
per hour (^R/hr). Background exposure rates in the environs of
typical uranium mining or milling operations generally average
about 20 MR/hr. Gamma—ray exposures from tailings can be reduced
to natural background levels by covering the tailings wi-ch
approximately three feet of earth.
Internal . dose is received from 222Rn emanating from tailings and
from other radionuclides. The critical organ is the lung due to
inhalation of radon daughters. Radon emanation is a function of
the radium concentration, material porosity, atmospheric
pressure, soil moisture, and inert cover. The majority of the
lung dose is due to the daughters of 222Rn decay. Sears et al.
(1975) have shown that the major contribution -co lung dose from
radon and its daughters is the tailings pile and not the
operating mill. The maximum daughter-product concentration will
occur just beyond the edge of the tailings pile in the downwind
direction.
Dose to the lung from inhalation of other suspended radionuclides
as well as internal organ dose from food chain transfer of
radionuclides dispersed in the local environment must also be
considered. For "worst possible" dose calculations an individual
is considered to live on the site'boundary of the mill within the
prevailing wind direction from the tailings pile. Sears et al.
(1975) have calculated annual dose rates to the whole—body and
critical organs of individuals for such cases. Tables A—2 and
A—3 are from their publication and are given for model mills in
New Mexico or Wyoming for either acid leach followed by solvent
extraction or for alkaline leach processes. These are "wors-
possible" cases and assume the individuals raise their entire
food supply locally. There are climatological differences, such
as wind speed, that produce the differences between the New
4A-8
-------
Exposure Rate/Radionuclide. Concentration
Radionuclide MR hr"1/pCi g"1 M& hr"1/indicated concentration
266 -6 -1 b
Ra + daughters 1.80 0.61/0.358 x 10 p g g Ra
214 -6 -1 b
Pb 0.20 0.70/0.358 x 10 /.g g Ra
214 -6 -1 b
Bi 1.60 0.54/0.358 x 10 Mg g Ra
238 -1 238
U + daughters 1.82 0.62/^g g U
a
One meter above ground; R=Roentgen
b 226 -1 238
Concentration of Ra in equilibrium with 1 g g U.
SOURCE: Adapted from NCRP (1976).
Table A-1
Calculated Exposure Rates for Radionuclides Uniformly Distributed in Soil
4A-9
-------
' • 1
HILL PROCESSES AND TAILINGS COMBINED
Total
Bone
Liver
Kidney
Spleen
Lung
Solvent Extraction Process
(mrem)
Mill Tailings Total
Body 20.2 16.6 36.8
232.4 168.0 400.4
23.6 19.4 43.0
40.1 27.0 67.1
23.5 21.6 45.1
29.3 60.4 89.7
a
Individual is 0.5 miles from the mill during the twentieth
when tailings cover maximum area, assuming 100 per cent of
Alkaline Leach Process
Mill
25.3
265.5
28.3
40.9
29.4
35.2
year of
the food
(mrem)
Tailings
16.1
166.3
18.9
27.1
20.8
84.9
operation
is pro-
Total
41.4
431.8
47.2
68.0
50.2
120.1
duced locally. The doses are the sura of the doses from airborne particulates
and Rn gas from operating mill and the active tailings area.
SOURCE: Adapted from Sears at al_ (1975)
Table A-2
Total Maximum Annual Radiation Dose to Individuals from an Operating Mill in New Mexico
L i
-------
MILL PROCESSES AND
Solvent Extraction
(mrem)
Mill
Total Body 16.5
Done 189.4
Liver 19.1
Kidney 32.5
Spleen 19.3
Lung 23.6
a
Individual is
when tailings
duced locally.
?99
and ^Rn gas
SOURCE: Adapted
Table A-3
Total Maximum Annual
Tailings
44.4
447.9
51.7
71.9
57.7
50.8
Process
Total
60.9
637.3
70.8
104.4
77.0
74.4
TAILINGS COMBINED
\
Alkaline Leach Process
(mrem)
Mill
20.6
215.6
23.0
33.2
23.7
28.4
Tailings
81.6
841.5
95.6
137.3
105.2
100.5
Total
102.2
1057.1
118.6
170.5
128.9
128.9
0.5 miles from the mill during the twentieth year of operation
cover maximum area, assuming 100 per cent of the food is pro-
The doses are the sum of the doses from airborne particulates
from operating mill and the active tailings area.
from Sears et
Radiation Dose
al (1975)
to Individuals
from an Operating Mill
in Wyoming
,
-------
Mexico and the Wyoming cases. From these tables, bone is
observed to be the critical organ, 2Z6Ra is the limiting
radionuclide, and drinking water and the milk food—chain are the
critical environmental pathways.
For comparison, predicted doses to individuals who could or do
reside at various locations in the vicinity of two Wyoming
uranium projects are presented in Tables A—4 and A—5. Table A—4
is from a project that began recently, and Table A—5 is from a
proposed project. The predicted radiation doses are based on
conservative assumptions by overstating the exposure. The
radiation dose depends on the distance and direction from the
source. The estimates are calculated using the mine and mill
site characteristics, mill equipment performance, and the actual
pathways in the vicinity of the projects.
Radiation dose may also be calculated for all other non-human
components of the local ecosystems. Wildlife and livestock have
nearly identical radiation sensitivities as humans, and it is
generally thought that if radioactive effluents are controlled to
meet human protection standards, then animal biological effects
will be of no concern. Plants and lower forms of animal life are
much more radiation resistant than higher forms. Table A—6 from
Whicker and Fraley (1974) shows that plant communities are in
general radiation resistant. Those plant communities found near
uranium milling operations in the western U.S. would not be
expected to show any radiation effects.
From calculated human doses, the expected biological effect or
risk may also be directly calculated. Two publications are
sources for the calculation procedures (UNSCSAR, 1972; NAS/NRC,
1972). The latter publication (called the BEIR report) has
expressed the overall risk of radiation dose in terms of genetic
and somatic effects. If large populations could be exposed, the
risk of genetic effects must be considered. The BEIR report
states that between 5 and 50 percent of all ill health is due to
genetic defects and estimates that 170 mrem/year to a large
population would increase the overall incidence of ill health by
5 percent.. Again, the increased incidence is thought to be
directly proportional to the additional dose.
Since the number of persons that might be exposed as a result of
mining and milling operations is relatively small, the
appropriate risk is not genetic effects in a large population but
somatic effects to the individuals involved. Cancer induction is
generally assumed to be the most sensitive measure of somatic
effects, and the BEIR report predicts that an additional exposure
of 170 mrem/year to the U.S. population would result in an
increase "of about 2% in the spontaneous cancer death rate which
is an increase of about 0.3% in the overall death rate from all
causes." The risk to any individual per unit radiation dose' is
expected to be the same. The risk is also directly proportional
to the radiation dose, and direct extrapolations to the doses
calculated for uranium mining and milling may be made.
4A-12
-------
Location
Point of maximum ground-
level concentrations off
site:
Site boundary in the
direction of the pre-
vailing wind:
Site boundary nearest the
sources of emission:
Nearest residence in the
direction of the pre-
vailing wind
(Carson Ranch)
Distance From
Source (meters)
2000
1800 (min)
2500 (max)0
1100
10,500
Exposure (mrem/year)
Sector Whole
Affected Body Kidneys Lungs
E
NE
W
NE
<0.01
<0.01
<0.01
<0.01
1.1
1.2
1.5
approx.
0.05
27.5
23.0
28.0
approx,
1.30
Bone
4.8
5.2
6.5
approx.
0.23
Based on 50 year dose commitments. To determine total annual exposure,
the accumulated dose can effectively be divided by 50.
b
The shortest distance to a site boundary within the affected sector.
c
The greatest distance to a site boundary within the affected sector.
SOURCE: Rocky Mountain Energy, 1975
Table A-4
Radiation Dose Commitment to Individuals from the Bear Creek Project
-------
f
Location
Bairoil,
35 km NE
Property
boundary,
2.5 km NE
Exposure
Pathway
Inhalation
External
Subtotal
Ingestion
Total
Inhalation
External
Subtotal
Ingestion
Total
Whole Body
2.3 x 10~3
1.9 x 10~
2.1 x 10
4.5 x 10~
6.6 x IO"3
2.6 x 10~2
8.8 x 10~^
1.2 x 10~
-3
4.5 x 10
-I
1.2 x 10
Bone
4.9 x IO""3
2.2 x 10~^
7.1 x 10
5.7 x 10~
6.4 x 10~2
5.7 x 10~
1.0 x 10~
6.7 x 10~
_2
5.7 x 10~
-1
7.3 x 10
Lung
3.0 x 10~2
1.8 x 10~^
3.2 x 10
4.5 x IO"3
3.6 x 10~2
3.2
8.1 x 10
3.3
_3
4.5 x 10
3.3
Bronchial *
Epithelium
1.48
1.48
62.5
62.5
62.5
uoses integrated over a 50-year period from one year of inhalation or ingestion.
Doses to whole body, lung and bone are those resulting from Inhalation of particulates
of U-238, U-234, Th-230, Ra-226, and Pb-210. The doses to the bronchial epithelium are
those resulting from inhalation of radon daughters.
SOURCE: NRC, NUREG, 0403, December, 1977
Table A-5
Radiation Dose Commitments to Individuals (mrem/yr) for the Sweetwater Project
-------
Exposures (kR) to Produce
Community Type
Coniferous Forest
Deciduous Forest
Shrub
Tropical Rain Forest
Rock Outcrop (herbaceous)
Old Fields (herbaceous)
Grassland
Moss-lichen
Minor
Effects
0.1-1
1-5
1-5
5-10
8-10
3-10
8-10
10-50
Intermediate
Effects
1-2
5-10
5-20
10-40
10-40
10-100
10-100
50-500
Severe
Effects
2
10
20
40
40
100
100
500
aShort-term exposures range from about 8 to 10 days, according to
the literature from which this table was derived. Exposures
might be reduced by factors of 2 to U for acute or fallout-decay
irradiation.
SOURCE: Adapted from Whicker and Fraley (197*0.
Table A-6
Estimated Short-Term Radiation Exposures Required to Damage Various
Plant Communities
4A-15
-------
Average Dose Rate*
Source (mrem/yr)
Environmental
Natural 102
Global Fallout 4
Nuclear Power 0.003
Subtotal 106
Medical
Diagnostic 72**
Radiopharmaceuticals 1
Subtotal 73
Occupational 0.8
Miscellaneous 2
TOTAL 182
*Note: The numbers shown are average values only. For
given segments of the population, dose rates considerably
greater than these may be experienced.
**Based on the abdominal dose.
SOURCE: Whicker and Johnson, 1978
Table A-7
Summary of Estimates of Annual Whole-Body Dose Rates in the United States
(1970)
4A-16
-------
Dose Rates (mrad y )
Source of Irradiation
External irradiation
Cosmic rays: ionizing component
neutron component
Terrestrial radiation
(including air)
Internal irradiation
3H
14C
40K
87Rb
aQPo
22°Rn
222Rn
226Ra
228Ra
238n
ROUNDED TOTAL
Gonads
28
0.35
44
0.001
0.7
19
0.3
0.6
0.003
0.07
0.02
0.03
0.03
93
Bone-
lining
Cells
28
0.35
44
0.001
0.8
15
0.6
1.6
0.05
0.08
0.6 .
0.8
0.3
92
Bone
Marrow
28
0.35
44
0.001
0.7
15
0.6
. 0.3
0.05
0.08
0.1
0.1
0.06
89
SOURCE: Whicker and Johnson, 1978
Table A-8
Dose Rates Due to Internal and External
"Normal" Areas
Irradiation from
Natural
Sources in
4A-17
-------
Prom inspecting the data in Tables A—2 through A—5 it is seen
that the BEIR report predictions are based on an exposure which
approximates "worst case" conditions which are orders of
magnitude higher than predicted for the general population in the
vicinity of an operating facility. Although such predictions are
useful in setting standards to protect the public, they are not
particularly meaningful to local populations who wish to assess
the "real world" risk of siting uranium processing facilities
near their communities. The doses to the average individual in
the vicinity of a model uranium mill has been estimated at
.045 mrem/yr (EPA, 1977). Therefore, the actual , risk to
populations is probably less than predicted above by a factor of
several 1000, assuming a linear relationship between dose and
health effects.
Additional perspective to the risk of radiation from uranium
production facilities is provided by comparing that dose
increment to the dose from natural radiation background, although
background radiation must be qualified since it is variable. The
cosmic ray component of background dose approximately doubles
with every mile of altitude increase from sea level to about
20,000 feet. The contribution from natural gamma-ray emitters in
the earth's crust also, of course, varies. A description of
background radiation whole body gamma dose should include
terrestrial dose equivalent (DE) and cosmic DE. The cosmic DE
has two components, an ionizing one and a neutron one. The
increased radium and thorium concentrations.in the western states
significantly increase the terrestrial dose. As a result the
annual background dose in the western states probably averages
over 200 mrem/year (Whicker and Johnson, 1978). Background is
measured during the preoperational phase of radiological
monitoring and should be used when comparing the doses calculated
for mining and milling operations. Tables A—7 and A—8 present
estimates of dose rates to U.S. inhabitants.
Another way of considering the biological effects of radiation
dose is to discuss life-span shortening of human populations. It
is generally thought that life-span shortening is an integration
of all radiation effects which are non-specific for low level
chronic radiation. The consensus is that a life-span shortening
of 1 day per total accumulated dose of 1 rem is a conservative
quantitative measure of human life-span shortening from ionizing
radiation (Whicker and Johnson, 1978). Again, assuming an
average individual dose from a uranium mill of 0.045 mrem/yr, an
accumulated dose of 1 mrem would not be received in a lifetime.
4A-18
-------
SOCIOECONOMIC CONSIDERATIONS
CHAPTERS
-------
CHAPTER 5
Socioeconomic Considerations
Socioeconomic impacts can be positive, negative, or more
commonly, a combination of both. Positive impacts frequently
include expanded employment and business opportunities, enlarged
local tax bases, and arrested decline in some rural areas.
Negative impacts may include shortages in public facilities,
shortages or inflated prices for housing and privately supplied
goods and services, and the emergence of new types of social and
political frictions. The potential for -negative impacts arises
because most energy reserves are in relatively isolated areas
where local communities may not have the expertise, the growth
management institutions, or the financial resources necessary to
accommodate rapid economic growth without major disruptions.
In general, neither the opportunities nor the problems presented
by uranium developments are as significant as those presented by
other new energy developments, such as coal mines, synthetic
fuels facilities, or power plants, because uranium mines and
mills typically have fewer employees. However, the opportunities
may be enhanced and many of the negative impacts avoided or
mitigated if growth is anticipated and public and private sector
decision makers cooperate in developing responses.
5-1
-------
Based on analysis of a number of uranium and other energy
development projects, impacts fall into the following categories:
• DIRECT IMPACTS ON EMPLOYMENT AND INCOME - The introduction
of a new mine or mill means new jobs, usually at higher
than average wages,
• INDIRECT AND INDUCED IMPACTS ON EMPLOYMENT AND INCOME
Mines, mills, and their employees make new demands for
local goods and services and spend a portion of their
incomes locally.
* POPULATION CHANGES - There may or may not be significant
numbers of newcomers co the community.
o PUBLIC SERVICES AND PUBLIC FINANCE - Tax revenues will
increase, but so will demands for public facilities and
services.
• HOUSING AND COMMERCIAL DEVELOPMENT - Demand for private
facilities and services also increases; if local
entrepreneurs do not respond, shortages and inflation will
result.
• ® SOCIOCULTURAL AND POLITICAL CHANGE - The introduction of
large numbers of newcomers may produce changes in both
formal and informal relationships.
» OTHER POTENTIAL CONFLICTS - These may include competition
between regulatory agencies for authority, competition
among alternative users of land (e.g., recreationists vs.
mining interests), or competition for local labor.
Because of the complex interaction between uranium development
projects and their host communities, there is no universal model
to predict socioeconomic impacts. Even in cases where models
exist, the state of the art in forecasting is not precise. Some
degree of uncertainty concerning the future is unavoidable. On
the other hand, in contrast to certain impacts to the physical
environment from uranium development, most adverse socioeconomic
5-2
-------
impacts are relatively easy to mitigate by institutional means.
Accordingly, one key to harmonious development of uranium
resources is early contingency planning by both the developer and
the host community, followed by an impacts—monitoring program
once development gets under way.
Socioeconomic impacts depend on the characteristics of the host
community, the region, and of the project itself. The effects of
all growth near the host community should be included in the
analysis of appropriate responses. Frequently, the impacts of a
single project are relatively negligible, while the impacts of
all new stimuli to the local economy, including one or more mines
and/or mills, are quite large. Table 5—1 summarizes important
factors in each category and will serve as a convenient checklist
for administrators and planners.
The following discussion provides a more detailed description of
impacts as well as other sources of information and possible
industry and government responses for each impact category. In
some instances, more text is devoted to problems than to
opportunities; this is not done because the problems will
necessarily outweigh the opportunities, but because with proper
attention and planning, most problems can be avoided or at least
alleviated.
5-3
-------
Impact Category
Related Mine/Mill Charactei latica
KfclaCfcd Coimpttnlf y
a I Choruct er tqc ICQ
(1) Direct Impacta on
Employment and
Income
(2) Indirect and
Induced Impacts on
Employment and
In co KB
• Couuitunlttea with high unemployment
will receive neei.^d new joba.
• Increased economic activity may
bring increased per capita Incotuea.
* Substantial growth of limited duration
(e.g., depleting rctierveu) or uncertain
duration (e.g.. uu a consequence of
volatility In uranium prices) may aet thu
community up for a buat to follow the boon.
• The rate of growth and/or uncertainty
concerning the t lining or dm at Ion uf
or breakdowns in other ayatema.
fhaulng of construction and oper-
ating employment.
Production levulu .
Marginal veraua cl early economic
ore grades .
Local hiring veraus the number of
ln-uilgraiiit> .
Labor retjulruuiciit for highly upu-
clallzed
Degree of rug lonal unemployment and
underemployment .
• liicruuiiud in local purchasing power nmy
ultimately lead to the availability ol a
wider range of private good a and aervicet*.
* Incrcabud growth may lead to new local
entrepreneurial opportunit leu.
• Locat lubor c o u 11» IBUy be forced upwatd by
c output! lion from the incoming uraniuiu in-
duatry , produc ing local inf1 a tIon. LocaI
buulneuticu way not bu uble to coiujiute with
highcr Industry waged. Reduced availability
of labor degradea quality of tiervIce.
* ttccruliuiunt ctforcu of the uranium
and construction companies und/or
union pot Iclts .
• Availability of on- the- Job training
program.
• Distance to local coununit leu.
• bixtizitt of local veraua uon-locu 1
purchati lug .
• Distance to local comrunnlt lea .
* Set i lumen t patterns of employ eeu .
Availability of upeclallzed aklllB and
cxiutence of local union hall.
Relationship of local ualarlea to cou-
titructloit and uranium project ualarleu.
Presence and et'f ectiveneua at local
vocational, technical or induutry training
programs .
Commuting distance to work site.
Distance to regional trade center.
freuent level of diversification.
Preucat local salary levcld.
Degree of regional unemployment and
undci'&iiployoient.
Likelihood of local versud non-local pur-
chaaeu by houticho) d and uervice Hector t*.
Aval lability and r.apital for f Inane log
bud inuim viiiiturtia.
(3) Population Chaugea
• l-'ewer of the community'^ yuung people
may leave becauue they perceive a lack
of economic oppurtunlty.
* fopulatIon gcouth may over tax enidtlng
pubi ic And pilvate fucilltlea and
aervlceu.
Employment totalu.
Charactcrlutlcu of Incoming work
forco and tamilieu.
• Present availability of public and
private facilities and iiervicea, houulag
and other amenitleu.
• Travel time to place of employment.
SOURCE: DRI
Table 5-1
Factors Influencing (he Occurrence of Socioeconomic Impacts
-------
Impact C«tcgorr
Opportunlt ies/Problema
Relate,! Mine/Hill Char
Btlco
Belated Community/Regional Characteristic!
(4) Public Service*
«nd Public Hnar.c.
T
tri
• Uranium developments lead Co large In-
creased in the local property tax base.
Ultimately, this nay provide for reduc-
tions In tax rates and/cr Increasea In
the level of public services.
• During the Initial development pcrlou,
tax base grouth may lag far behind popula-
tion growth. Local jurisdictions may also
encounter Institutional constraints In
attempting to borrow funda to finance
development. The result may be Increases
In local tax rates and/or degradation in
public services for several years.
• Public finance problems prevent llinely
provision of services and facilities.
• Dissatisfaction of workers and their
families with their Duality of life way
lead to alienation and to high labor
turnover rates, low productivity and higher
production coats.
* Dissatisfaction with reductions In tl.«
quality of life may lead to increase'!
opposition to future energy developments
by residents and state and local
government:*.
Phasing of construction and
operating employment.
Tinting of assessed valuation
increases.
Juriadlctlon(e) receiving new
assessed valuation versus thot»«
receiving population.
• Local rev
• Institutional
borrowing.
OD public
• Jurisdlctlon(s) receiving population
Increases versus those receiving incre*»«ult.
» Salaries of Incoming workers.
• Housing preferences of incoming
workera.
• Degree ot local veruu* non-local
purchattlng.
• Timing and duration ot uranium
development.
• Availability and coat of factor* of
production.
• Present diversity of local economy.
• Constraints 0:1 borrowing development
capital, obtaining mortgage*.
• Availability* cost, »nd quality of
existing housing.
• Local entrepreneurial ability.
SOURCE: OKI
Table 5-1 (continued)
Factors Influencing the Occurrence of Socioeconomic Impacts
-------
Impact Category
Opportunttlea/l'robleiiifi
Rulnteil Hlnc/Hll) Clmrnctcl'lat lea
Related Communlty/Reftlunal Characterlatlea
(6) Soclocultursl and
Political Change*
LTI
• Newcomers nay bring ssaeta (education,
managerial skills) wltlch can benefit
the connumity.
• Values conflicts may arise between old-
tine and newcomer cultures.
• Old-tlmera may experience a loss of
Intimacy and "small town feeling"
as the community grows.
• Old-tlmcra may lose political control
of their community.
• Housing shortages, shortages or de-
gradation In the quality of other
privately and publicly financed goods
and services, and rural sprawl settle-
Bent patterns all tend to produce more
alienation of rcsldcnta. This aliena-
tion also further Increases the likeli-
hood that old-timers will resent the
changes in life-styles snd that values
conflicts will urine.
• Local governments' inability to handle
their own houulng and public finnnca
problcmn ntny bring more ntnte nnd
federal Intervention Into community
affairs. This intervention may be
rcacnted by local rcitldrnta and
officials.
• Social characteristics of
incoming work force.
• Expectations of quality of life.
• Existing social, political and cultural
structures.
• Settlement patterns encouraged by
community.
• Efforts to assimilate ne
(I) Other Potential
Conflicts
• Lou paying jobs in public and
private aector cannot compete for
labor.
• Competition for land may bid up
prices. Land uses change (margins!
agriculture Isnd taken out of
production).
• Competing regulatory authorities
auy Increase uncertainty concerning
the occurrence and timing of develop-
ment and Chun hinder efforts to
mitigate impacts.
• Wage rates of construction and
uranium industry.
• Location of development and
characteristics of surrounding
area.
• Vage rstea and extent of underemployment
in other local sectors.
• Existence of planning and lonlog prohibit!
some uses.
• Applicable state regulatory structures.
SOURCE: DEI
Table 5-1 (continued)
Factors Influencing the Occurrence of Socioeconomic Impacts
-------
5.1
Direct Impacts on Employment and Income
Changes in employment and income as a result of uranium-related
development cause direct impacts on the local and regional
economy. These impacts are usually viewed as positive by the
host community. The benefits of these changes can be increased
and other indirect negative impacts reduced if uranium projects
can hire local residents; for instance, local unemployment can be
reduced and per capita income increased, thereby reducing the
negative impact of requiring new schools before the tax base is
available to pay for them. Generally, total direct impacts on
employment and income will be a function of the following:
• The number of facilities being built in the same area.
When several projects occur in the same region, each
succeeding project will rely more on outsiders for
employees.
• The phasing of development of multiple facilities.
Construction—related employment can often be made much
more stable if projects are timed so that essentially the
same work force is employed for each project.
• The level of effort by the mine or mill to hire local
residents.
• The labor requirement for highly specialized skills,
Local labor pools in rural areas are not often able to
provide workers with highly specialized or technical
expertise,
• The degree of regional unemployment. Improper functioning
of formal or informal information networks on employment
opportunities may lead to the number of newcomers
exceeding the number of new jobs, actually increasing
unemployment.
5-7
-------
5.1.1
Empioyment
The three most common analytical approaches used to estimate the
number of local employees versus newcomers are (1) to assume all
employees are newcomers, (2) to extrapolate from the ratio of
newcomers found in similar projects, and (3) to analyze the local
market's capabilities to meet project needs. To assume that all
new employees will be newcomers is a conservative approach, often
taken where there is little available data. It is based on the
premise that local hirees will be vacating jobs that will be
filled in turn by newcomers. The extrapolation approach is to
use the results of surveys taken in previous energy-impacted
areas. The market—analysis approach is to analyze the skills of
the local labor force and relate them to the needs of the mine or
mill.
In analyzing direct employment, a distinction is made between
construction and permanent workers. This distinction is
important in both assessing long—term impacts and in considering
mitigation measures. Since construction workers tend to be
temporary, area populations may fall as rapidly at the end of
construction as they rose at the beginning. Thus classrooms and
utilities systems built to handle the increased population will
not be efficiently used, but the remaining residents will still
be responsible for the debt incurred for construction of such
facilities.
5-8
-------
/
Project
Mines
Surface
Surface
Surface
Underground
Underground
Underground
.Mills
Mill (acld-
leach)
Mill
(carbonate-
leach)
Mill (acid-
leach &
akaline-
leach)
Mill (acid-
leach)
Start-up
Date
old
1970's
mid
1950' s
early
1970'»
projected
early
1980's
early
1970's
early
1970's
mid
1950's
expanding
late
1970'»
early
1970's
old
1950's
converted
aid 1970' »
mid
1970'i
Normal
Capacity
1,700 TPO
varies
according
to -jrade
2,000 TPD
4,500 TPD
1,100 TPD
600 TPD
3,000 TPD
expanding to
6,000 TPD
750 TPD
1,200 TPD
1,000 TPD
Construction
Time
7 month*
2 years
2-1/2 years
(initially
scrapper
operation)
10 years for
all construction
to be complete
2-1/2 year*
4-1/2 years for
all construction
to be complete
11 months
for expansion
20 nontc*
4 years for
entire
conversion
1 year
(includes 2
month delay
for NRC
Statement)
Peak.
Construction
Force
141
HA
HA
300
60
HA
600
60
(all surface
. buildings)
120
(conversion)
70
Total
Operating
Force*
141
455
220
750
164
ISO
421
83
135
51
\
Union/
Non-Union
non-union
union
non-unloa
HA
mixed
union
union
mixed
non-union
non-union
'Includes office and naintenance personnel.
SOURCE: DRI interviews with mine and mill operators.
Table 5-2
Estimates of Work Forces for Selected Uranium Mines and Mills
5-9
-------
Examples of the number of operation and construction employees
and construction times for various types of uranium mines and
mills are shown in Table 5—2. These vary widely from project to
project, depending on such factors as:
• Geologic conditions
• The resultant mine and mill plans and engineering
specifications
• The construction techniques used (e.g., extent of
prefabricated subsystems)
• The geographic location (including the consideration of
established transportation systems and distance to
regional trade centers)
• The existence of regional union labor pools and types of
skills represented
* The discretion allowed project managers to make trade-offs
to use smaller construction forces over longer periods of
time
The prime contractor for the construction project and operating
companies for mine and mill facilities are the best sources for
obtaining data on employment. Where an employer's data are
unavailable, general figures on worker productivity may be used
in combination with estimates of mine output. Table 5—3 gives
the average worker- productivity in the U.S. for underground and
open— pit mines. As indicated, it is important to use recent
estimates because productivity has fluctuated sharply with
technological innovations and changes in mine safety
requirements.
5-10
-------
1
Tons Per Man- Shift
Underground Mines Open Pit Mines
Miners
1969 7.8
1970 8.5
1971 8.1
1972 8.6
1973 8.2
1974 8.3
1975 6.4
1976 7.5
Source: ERDA,
Table 5-3
Service
and
Support
18.0
18.6
18.1
19.4
15.3
19.0
10.6
9.0
January
Total
5.4
5.8
5.6
6.0
5.4
5.8
4.0
4. 1
Miners
16.6
19.1
21.7
22.7
28.0
30.7
26.1
21.3
1976.
Service
and
Support
22.1
27.1
27.8
32.0
38.6
35.3
29.6
30.6
Total
9.5
11.3
12.2
13.3
16.2
16.4
13.9
12.7
Changes in Worker Productivity
5.1.2
Income
Wage rates for construction and operating employees will normally
be considerably higher than those of the local service and public
employees, even allowing for variations such as region, skills
involved and union pay scales. Dranium industry employees can
further augment their base pay by overtime, bonuses and other
incentives based on individual productivity. As a result, it is
frequently possible for an experienced miner taking advantage of
all offered incentives to make $30,000 per year. Typical wages
received by employees in various industries are given in
5-11
-------
Table 5—4. Wage differentials for different skills are
illustrated in Table 5—5.
Potential actions to enhance opportunities and/or mitigate
problems include;
Community actions
• Vocational training programs for local residents
• Accurate job status publicity (to prevent in—migration of
workers in excess of available jobs)
Industry actions
• Local recruitment efforts by both construction contractors
and operators
For more information see:
General sources on worker characteristics
• University of Wyoming. Agricutural Experiment Station.
Profile of a Rural Area Work Force: The Wyoming Uranium
Industry. Research Journal 79, Laramie: January 1974.
• Uhlmann, Julie M., et al. A Study of Two Wyoming
Communities Undergoing the Initial Effects of Energy
Resource Development in the Powder River Basin: Buffalo
and Douglas, Wyoming—1975. Laramie: University of
Wyoming, 1976.
• Mountain West Research, Inc. Construction Worker Profile.
Washington, D.C.: Old West Regional Commission, 1976.
Other sources
• Environmental Impact Statements for specific facilities
(e.g.. Rocky Mountain Energy Company, Bear Creek facility,
Converse County, Wyoming; Minerals Exploration Co., Red
Desert facility, Sweetwater County, Wyoming; Rio Algom,
La Sal facility, San Juan County, Utah)
• State and regional employment offices
• Unions
5-12
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Occupation
Wyoming
Hew Mexico
Utah
Uranium Industry
Mine
Mill
$1.250 - 1.833
$1,250 - 1,667
$1,000 - 1.833
$1.000 - 1.500
$1,500 - 1,833
$1,000 - 1.500
Carpenter (union)
(non-union)
Police Officer
Fireman
City Laborer
City Mechanic
Clerk-Typist (steno)
(bookkeeper)
Auto Mechanic
Truck Driver (heavy)
(light)
$1,600 - 1,900
$ 920 - 1,070
$ 780 - 930
$ 700 - 850
$1,190 - 1,340
$ 500 - 650
$ 580 - 730
$ 930 - 1,080
$ 840 - 990
$ 630 - 780
$1,730 - 1,880
$ 870 - 1,020
$ 800 - 1.100
$ 600 - 800
$ 550 - 650
$ 800 - 900
$ 520 - 670
$ 800 - 900
$1,130 - 1,280
$ 780 - 930
$ 700 - 850
$ 700 - 850
$ 680 - 830
$ 520 - 670
$ 870 - 1.020
$ 440 - 590
$ 660 - 810
$ 910 - 1.060
$ 490 - 640
SOURCEl 1977 State Job Listings.
Table 5-4
Average Monthly Salary Ranges for Selected Areas
-------
Job
Category
mior lab
echnician,
Industry
Average
under
$10,000
Mill
Average
under
$10,000
Mine
Average
under
$10,000
unskilled,
beginning
secretary
Secretary,
entry level,
semi-skilled
$10,000-
15,000
$10,000-
12,000
$10,000-
15,000
Skilled
draftsmen,
operators ,
miners
Supervisory
personnel
Administration
$15,000-
20,000
$20,000-
25,000
above
$25,000
$12,000-
18,000
$14,000-
20,000
above
$20,000
$15,000'
20,000
$20,000
25,000
above
$25,000
SOURCE: DRI interviews with industry officials in Wyoming, Utah, and
New Mexico.
Table 5-5
Examples of Average Wages for Uranium Industry Workers
5-14
-------
5.2
Indirect and Induced Impacts on Employment and Income
The direct changes in employment and income associated with
uranium development can cause indirect and/or induced changes in
virtually every other sector of the local and regional economies.
Uranium development may produce indirect changes in other basic
industries; for example, increases in uranium-linked industries,
such as railroad— and mining—equipment suppliers, may occur.
Capital expenditures and salary dollars invested in the local
economy by the uranium industry and associated activities
increase spending, which leads to induced changes, such as
increased purchasing power, economic activity, and supporting
(nonbasic) jobs.
Indirect changes are not always positive. For example,
agricultural production may decrease because of competition for
local labor. This in turn could reduce economic diversity.
5.2.1
Non-Basic Economic Activity
Uranium development also stimulates changes in nonbasic economic
activity. In a simple model of a local or regional economy,
basic economic activities are those which import purchasing power
from outside the region. Nonbasic activities, activities which
provide goods and services to households and/or businesses within
the region, are considered to be a function of the level of basic
economic activities. Nonbasic economic activities include some
(but not necessarily all) wholesaling, commercial and financial
5-15
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establishments, some light industries, the local housing
industry, and the local public sector.
The extent of indirect or induced impacts in the host community
depends upon the following:
The distance to the nearest regional trade center.
Regional trade centers are capable of absorbing a portion
of the increased activity due to area resource development
without much disruption. Small rural communities are not
able to do this.
The shopping habits of local residents. As an example,
Albuquerque is within easy driving distance (all
interstate) of Grants, New Mexico, and many residents of
Grants drive there to shop. This may tend to reduce the
incentive for Grants to greatly expand its businesses.
Present diversification of the local economy. Many
businesses in small rural communities could not handle a
sudden, large increase in business. Limited shopping is
available, usually consisting of a drug store, small
department— type store, a limited item grocery store, etc.
5.2.2
Analytical Approaches
The analytical approaches used most frequently for estimating
changes in nonbasic economic activity due to changes in basic
economic activity are . export—base multipliers and input-output
models. Export—base analysis expresses the relationship between
basic and nonbasic activities in terms of simple ratios, or
multipliers. Multipliers may be calculated using either
employment or income data.
Input-output analysis is based on the interrelationships of firms
5-16
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both as purchasers of inputs and as producers of outputs. It
provides a means of determining how changes in the output of any
industry will affect each sector of the economy. Input-output
analysis is a more sophisticated technique than export—base
analysis; however, it is used much less frequently in impact
assessment. One reason is the cost. Up-to-date input-output
tables are frequently unavailable for the area to be studied and
are expensive to prepare. The most common approach is the
employment multiplier, primarily because of ease of application.
Income multipliers may be used almost as easily.
Depending on the local economic and political environment (e.g.,
present levels of unemployment and underemployment and political
attitudes toward growth), the host community may want to maximize
or minimize the indirect and induced effects of the proposed
development.
f 'N
Potential actions to enhance opportunities and/or mitigate
problems include:
Community actions
• Informal actions (e.g., Chamber of Commerce) to publicize
business opportunities
Industry actions
* Maximizing (or minimizing) local purchases of supplies and
material
• Encouraging employees to live nearby (or to commute to
nearby communities)
__ J
5-17
-------
For more information see;
More detailed descriptions of analytical techniques
• Miernyk, William H. The Elements of Input— Output Analysis.
New York: Random House, 1965.
• Tiebout, Charles M. The Community Economic Base Study .
New York: Committee for Economic Development, December
1962.
• Hirsch, W.Z. Urban Economic Analysis. New York:
McGraw-Hill, 1973. .
Examples of use of these techniques
• Employment Multiplier: Denver Research Institute,
University of Denver (e.g., Gilmore, et al., Socioeconomic
Analysis Appropriate for an Environmental Impact Statement
for a Uranium Mine— Mill Complex at Bear Creek, Wyoming) .
• Income Multiplier: Arizona State University, Department of
Economics (e.g., Chalmers, James A. and E.J. Anderson
[Mountain West Research, Inc.], Economic/Demographic
Assessment Manual. Denver: Bureau of Reclamation,
November 1977) .
• Input— Output: University of New Mexico, Bureau of Business
and Economic Research, Albuquerque, New Mexico.
5.3
Population Changes
Estimates of population growth related to development are based
on employment projections. First, employment estimates are
adjusted to account for any expected increases in jobs held by
local residents (e.g., changes in unemployment levels and/or
labor participation rates) . The resulting estimates, that is
jobs to be taken by outsiders, are then translated into estimates
of population growth using one of the following three techniques:
5-18
-------
• Labor participation — The ratio of labor force members to
population. This technique assumes that this ratio is the
same as the regional average.
• Worker characteristics — The characteristics of the work
force are assumed to be similar to those found in surveys
at previous project sites. Singles and families are
projected separately using such variables as head of
household, family size, and number of children. Different
variables are normally used for construction and operating
employees.
• Cohort survival — Births, deaths, and net migration are
projected separately for each age and sex cohort of the
population at periodic intervals. Additional assumptions
must be made concerning the age and sex distribution of
newcomers.
While the cohort survival technique provides the most detailed
results, it is the most time consuming and requires the most data
and initial assumptions. This added detail may be appropriate in
special situations such as where there is concern over the size
of the elderly population or where mines or mills are located
near Indian reservations.
5.3.1
Settlement Patterns
In addition to the magnitude and timing, the geographic
distribution of income and employment effects among local
communities and taxing jurisdictions is important. Possible
settlement patterns are influenced by the following:
5-19
-------
• Loca-cion of the new facility
• Travel time to the point of new employment
• Present availability and quality of public amenities
(e.g., utilities, schools, public services, recreation
facilities)
• Present availability and quality of private facilities and
services (e.g., shopping and medical care) and presence of
employment opportunities for any other wage earners in
families
• Present availability and quality of housing
• Announced plans for new housing developments, and public
and private facilities and services
• Residential choices of people presently working at or near
the point of new employment
• Special incentives (e.g., availability of subsidized
housing or special transit systems)
5.3.2
Prediction Techniques
Three of the most commonly used approaches for predicting the
geographic distribution of impacts are as follows:
r
• The gravity model, in which community attractiveness is a
function of population mass and distance
• A community weighting approach, which incorporates housing
prices and subjective assessments of the community
attractivenes s
• The Delphi technique, a system for eliciting expert
opinion by sequential rounds of questioning
. J
5-20
-------
None of these methods have been shown to be particularly accurate
predictors of settlement patterns. It may be that the decision
process is sufficiently random that no technique is a good
predictor. In some instances, it may be better to think of
worker settlement patterns as a policy variable rather than
something to forecast. Workers might be encouraged to live in
the communities where their presence causes the most favorable
impacts and the fewest problems.
Potential actions to enhance opportunities and/or mitigate
problems include:
Community actions
• Encouragement of housing growth to accomodate types of
population desired (e.g., permanent single family units or
mobile homes and barracks)
• Use of growth management techniques (e.g., zoning, utility
moratoria, higher tap fees) in those areas which would
suffer the most adverse impacts
Industry actions
• Recruitment efforts focused on desired types of employees
• Informal encouragement of employees to live in designated
areas
• Incentives to employees to live in designated areas (e.g.,
bus service to mine/mill sites, subsidized housing)
V
5-21
-------
For mors information see:
Examples of population analysis techniques
• Labor Participation: Tennessee Valley Authority. Final
Environmental Statement Morton Ranch Uranium Mining.
Chattanooga, Tennessee: January 1976.
• Worker Characteristics: U.S. Nuclear Regulatory
Commission. Draft Environmental Statement Rocky Mountain
Energy Company's Bear Creek Project. Washington, B.C.:
January 1977.
• Cohort Survival: Wyoming. Department of Economic Planning
and Development (DEPAD). The Navajo Nation, Office of
Program Development. The Navajo Economic-Demographic
Model. Window Rock, Arizona: January 1976. Available
from Office of the State Planning Coordinator, Salt Lake
City, Utah.
Examples of techniques for analyzing population settlement
patterns
• Gravity Models: Chalmers, James A. "The Role of Spatial
Relationships in Assessing the Social and Economic Impacts
of Large Scale Construction Projects." Natural Resources
Journal, April 1977, pp. 209—222.
• Community Weighting: Williams, David, et al. Impacts of
the Proposed Peabody Rochelle Coal Mine. Reston,
Virginia: USGS, 1978.
• Delphi: Schmitz, Steve, et al. Growth Monitoring System
Project Report for State Planning and Management Region
XI. . Rifle: Colorado West Area Council of Government,
1977.
5.4
Public Services and Public Finance
The development of uranium resources may have major impacts on
public finance and public services. Many local jurisdictions
hosting uranium development eventually benefit from an increased
tax base. In the short run, however, uranium developments in
5-22
-------
sparsely populated areas may also cause serious public finance
problems. When a new development is initiated, the need for
public expenditures frequently grows much faster than revenues
from existing sources. This is particularly true for city, or
town governments, since development normally takes place outside
corporate limits.
Local officials may confront the following problems:
• Revenue shortfalls (cash flow problems) resulting from the
lag times in receipts of increases in revenues and the
lead times required to provide new facilities.
• The potential for mismatches between those receiving
revenue increases and those confronted with increases in
demands for services (uranium development can take place
across county, school district or even state lines from
where population settles). For example. Grants, in
Valencia County, New Mexico, is the home of employees of
the Kerr-McGee-Ambrosia Lake Hill, the Rancher's Johnny M
Mine, and the Gulf Mt. Taylor Mine—all located in
McKinley County. Municipalities almost always have these
problems, since uranium operations are rarely within
corporate limits.
• The high level of risks for local bonding. The timing and
duration of uranium developments are subject to
uncertainty. Since the tax base depends on their
presence, their delay or abandonment imposes a high bond
repayment burden on the residual tax base.
• The potential for sharp increases in public operating
costs. Salary costs frequently increase due to
competition with the new uranium-related jobs.
• The need for new expertise. The financial expertise
necessary to be successful in obtaining outside assistance
or in obtaining satisfactory arrangements with outside
financial institutions or bond markets is frequently not
available in small communities.
J
5-23
-------
The revenues and expenditures associated with uranium development
must be projected to determine net impacts. Projections should
be made at least on an annual basis to reflect concerns over
front-end financing and cash flow problems. They should be made
separately for each relevant jurisdiction to address the issue of
mismatches between those receiving the costs and those receiving
the benefits.
5.4.1
Revenues
A close examination of the tax structure of the state where the
operations are located is necessary for accurate estimates of
public revenues directly related to uranium production.
Table 5—6 lists the taxes applicable in the state of Utah.
Table 5—7 provides an example of the taxes due from a typical
mining operation in Utah. Other states vary greatly from this
example. The approach commonly used to project other indirect
public revenues includes dividing revenues into sub-categories
which can be estimated based on previously derived estimates of
increases in real property,, production, income and/or population.
Estimates of virtually all revenues other than those directly
related to uranium development are made on a per capita basis.
Some more complex estimating methods involve use of input-output
analysis to derive public sector revenues and use of multivariate
relationships derived from cross-sectional analysis.
5-24
-------
s
Title k
Legal
Citation
General
Property
59-1-1
to
59-11-16
Sales
and Use
59-15-4
59-16-3
11-9-4
11-9-6
11-9-4
11-9-6
Corporate
Franchise
59-13-65
Unemploy-
ment
Compensa-
tion
35-4-7
Motor
Fuel
41-11-6
Motor
Vehicle
Registra-
tion
41-1-127
Mine
tlon
59-5-67
Year
Enacted
1849
1933
1959
1974
1931
1936
1923
1909
1937
Basis of Tax
30Z of "reasonable fair cash value"*
of real and tangible personal
property. Metalliferous mines
assessed at $5 an acre plus two
times average net proceeds. In
addition, machinery and other
property of mines assessed at 30"
of reasonable fair cash value.
Retail sales or use of tangible
personal property, utility services,
admissions, meals, general services.
hotel, motel, laundry and dry
cleaning.
Local option — county, city.
Local option — county (only Salt
Lake, Ueber and Davis Counties).
Net income allocable to state; no
deduction for federal taxes.
Base is the latest average annual
wage; this changes every year —
currently $9,600.
Gallons of motor fuel sold or used.
Motorcycles, private autos, house
trailers, manufacturers, transport-
ers, dealers, and wreckers— flat
fees. Motor vehicles, trailers.
and semitrailers used for trans-
property— unladened weight of
vehicle.
Gross amount received or gross value
exempt.
Rates
Varies in each city, county
and school district. In
1977, total property tax
ranged from 46 mills in an
unincorporated area of
Daggett County to 114.95
in Salt Lake City; state
averaee was 78.59.
41 of purchase price.
3/4Z of purchase price.
.
1/4Z of purchase price.
4Z of net taxable Income.
Minimum tax for state banks
and corporations Is $25.
A range of 1.3Z to 3Z
of covered payroll. En-
tire tax paid by employer.
9c per gallon.
(July 1, 1978)
Motorcycles and small
trailers — $2.50; private
autos — $5.00; house
trailers — $5.00; commercial
vehicles— $7.50 to $535,
plates — $1.00 per set.
1Z.
"\
'
Allocation
and Use
School districts.
municipalities.
counties, and
special districts.
To General Fund.
Returned to local
unit Imposing tax.
Transit District.
To' Dnlform School
Fund; distributions
to districts under
minimum school
program.
To Unemployment
Compensation Fund;
used to pay unem-
ployment benefits.
To Highway Con-
struction and
Maintenance Fund;
used for highway
construction and
maintenance.
Cities and coun-
ties get first
$2,000,000 after
admin, expense.
Balance: 3/4 to
cities and coun-
ties, 1/4 to State
Hifchwav Fund.
To General Fund.
'"Seasonable fair cash value" la not necessarily current market value. Presently the actual assess-
ment ratio is between 6Z to 24Z in the extremes, but the state aim Is for all property to eventually be
assessed at 20Z of current market value.
SOURCE:
Compiled by the Utah Foundation from the Utah Code Annotated 1953, as amended.
Updated based on interviews with the Utah State Tax Commission.
Table 5-6
Examples of Utah Taxes to be Paid by Uranium Mining and Milling Companies
5-25
-------
Assumptions;
• Initial investment - $45,000,000 (1977 dollars)
Cost of mine = $25,000,000
Cost of equipment = $ 1,000,000
• Mine normal capacity = 1,700 TPD
• Mill normal capacity = '1,000 TPD
• Pounds of yellowcake/year = 600,000
• Selling price • $ 40
• Complex is on BLM land
• Estimated taxes for first year of operation (1978)
• Uranium company property and assets are distributed equally between
Utah and another state
Property Tax
Assessed value of mill is 20% of $25,000,000 $ 5,000,000
Assessed value of machinery is 20% of $1,000,000 200,000
Assessed value is 2 times $1,300,000 (net proceeds -
gross proceeds minus mining cost and machinery
purchased during year) 2,600,000
$ 7,800,000
Tax rate 60 mills
$ 468,000
Sales or Use Tax
$3,000,000 expended annually for mine and mill
supplies times 4.75X $ 142,500
Corporate Franchise Tax
Net proceeds ($1,300,000) minus 1/3 for depletion
allowance (432,900) = $867,100
$867,100 divided by two (because company equally split
between two states) = $433,550
$433,550 x 4Z : $ 17,342
Unemployment Compensation
Estimate for 210 employees earning $3,816,000 is 2.7%
on the first $9,600 paid to each employee during 1978
($9,600 x 210 = $2,016,000 x 2.7%) $ 54,432
Mine Occupation Tax
Gross proceeds ($2,400,000) minus deduction
($50,000) = $2,350,000 x 1% $ 23.500
TOTAL $ 705,744
SOURCE: DRI
Table 5-7
Estimated Major Utah Taxes to be Paid by a Hypothetical Uranium Mine-Mill
Complex
5-26
-------
Another important variable is the revenues mix of local
jurisdictions. Jurisdictions which rely heavily on ad valorem
taxes are the hardest hit by revenue lags. Sales taxes and tap
fees are examples of sources which arrive earlier. Equally
important is consideration of the fiscal position of the
jurisdiction • before development begins. Counties with
substantial amounts of other resource production, such as oil,
gas, and coal, are in a much better position to address uranium
development problems than those with predominantly agricultural
tax bases.
5.4.2
Expenditures
A variety of techniques are available for estimating needs for
new public expenditures. Two of the most common approaches are
the use of national or regional per capita standards and the use
of the "best judgment" of local officials responsible for
providing the services, . No approach is without problems, and a
detailed analysis of these issues is necessary before carrying
out an expenditure analysis.
Special emphasis should be given to. the differences between
public facilities and services required by permanent residents
and those required by temporary construction workers. This is
necessary to avoid overestimating the increases in public
expenditures. Needs also vary greatly from community to
community. A useful rule of thumb for early planning is that
roughly $1,000 per year in new operating expenditures and 55,000
5-27
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in new capital outlays are required for each new resident if the
quality of local services is to be maintained (Moore, 1976).
Some capital outlays need to occur one to two years prior to the
arrival of the new construction work force.
5.4.3
Public Finance Constraints
With the exception of jurisdictional mismatches, most
development-related public finance problems are relatively short-
term, lasting from two to seven years. Host communities and
other local jurisdictions require either outside capital or a
substantial line of credit to get through these critical years.
Unfortunately, most experience thus far has been that outside
assistance and local borrowing have not been sufficient to
prevent a reduction in the level of local services. Local
borrowing is inhibited by the following mutually reinforcing set
of constraints.
r
• ACCESS TO INFORMATION — Local officials often do not
receive early warning of impending development. Industry
is faced with development uncertainty due to such things
as litigation and international resource prices.
• ACCESS TO EXPERTISE — Small communities may have little
experience in capital improvements programming or other
intermediate range budgeting techniques, the bond market
or in federal grantsmanship.
• ACCESS TO CAPITAL — Institutional constraints may limit
local governments' participation in the bond market. For
example, statutory bonding limits range from 10 percent of
assessed valuation for school districts to 2 percent for
counties in Wyoming.
5-28
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CONSTRAINTS, Continued
• RISK —The uncertainty of the timing of development and the
possibility of abandonment may cause concern that public
facilities financed to accommodate growth will not be
needed and that bonds will have to be paid out of the
existing tax base.
• ABILITY TO PAY — Some local entities may be unable to pay
off early years' debt service without large increases in
tax rates. Voters may often refuse to pass bond issues
even when the need for new facilities is apparent.
V J
Potential actions to enhance opportunities and/or mitigate or
avoid these problems include:
•Community actions
• Tax base sharing where there is a jurisdictional mismatch
(Wyoming has examples of both formal mechanisms — the
state's Joint Powers Act — and informal mechanisms —
movement of the school district boundary within Converse
County)
• Shifts in reliance from taxes with long lead times (e.g.,
property taxes) to faster revenue sources (e.g., utilities
tap fees)
• Extensive us.e of external assistance programs (e.g.,
Environmental Protection Agency, Economic Development
Administration, state energy impact assistance funds)
Industry actions
• Coordination of scheduling of construction with local
officials
• Temporary financial assistance (e.g., planning grants) to
particularly needy local governments
• Prepayment of future taxes (only Utah presently has this
option)
V ^___ _
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POTENTIAL ACTIONS, Continued
State actions
• Establishment of energy impact assistance funds with a
portion of energy—related revenues
• Provision of local technical assistance in planning,
growth management, and grantsmanship
• Establishment of institutions to coordinate assistance and
ensure that problems are mitigated (e.g., Wyoming
Industrial Siting Council, Wyoming Department of Community
Development, New Mexico Energy Resources Council, Colorado
Impact Assistance Coordinator, and Texas Energy Advisory
Council)
For more information see:
General discussion of fiscal analysis
• Real Estate Research Corporation. Costs of Sprawl.
Washington, D.C.: U.S. Government Printing Office, 1974.
• Muller, Thomas and Grace Dawson. The Fiscal Impact of
Residential and Commercial Development: A Case Study.
Washington, D.C.: The Urban Institute, 1972.
• Gilmore, John, et al. (Denver Research Institute).
Impacts of Western Energy Development. Washington, D.C.:
The President's Council on Environmental Quality, 1978.
Examples of the use of alternative techniques
• U.S. Nuclear Regulatory Commission. Draft Environmental
Statement Rocky Mountain Energy Company's Bear Creek
Prelect. Washington, D.C.: January 1977.
• Combination: Baldwin, Thomas E., et al. A Socioeconomic
Assessment of Energy Development in a Small Rural County:
Coal Gasification in Mercer County, North Dakota, Vol. II.
Argonne National Laboratory, 1976.
• Per capita: Laholm, Arlene G., et al. The Economic Impacts
of Construction and Operation of Coyote Station £ 1
Electrical Generation Plant and Expansion of Coal Handling
Facilities at the Beulah Mine of Knife River Coal Company.
Denver: Stearns—Roger, Inc., 1976.
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MORE INFORMATION, Continued
Discussions of mitigation alternatives
• Briscoe, Maphis, Murray and Lament, Inc. Action Handbook
for Small Communities Facing Rapid Growth. Denver:
Environmental Protection Agency, 1978.
• Moore, K.D., et al. (Denver Research Insitute).
Mitigating Adverse Socioeconomic Impacts of Energy
Development; Present Programs and Mechanisms and Further
Policy Options. Washington, D.c.: D.S. Department of
Energy, 1977.
• Centaur Management Consultants, Inc. Assistance for Energy
Developers: A Negotiating Guide for Small Communities,
Washington, D.C.: Energy Research and Development
Administration, 1977.
_J
5.5
Housing and Commercial Development
In addition to shortages in public facilities and services, rapid-
growth can lead to shortages in housing and in commercial
development. Housing problems are often the first major sign of
population growth impacts. Prices for new construction and for
rental units begin to increase as demand overtakes supply. The
private business sector of the local economy is not able to keep
up with demand either. Financing for expansion of commercial
establishments is difficult to obtain or .nonexistent; existing
businesses are accustomed to operating under stable conditions
and may not have the stock or the help to handle increased
business.. In times of rapid growth, the private sector suffers
many of the same problems as the public sector.
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5.5.1
Housing
Most assessments of housing impacts consist of an estimate of the
increased need for housing. These are usually based on housing
surveys done in the area by local lending institutions, realtors
or planning agencies. Information collected often includes the
number of housing units by type, such as single family,
apartments, and mobile homes; types of housing available; price
or monthly rental; age of dwelling; and household income levels.
However, equal attention should be (and seldom is) given to
whether suppliers are likely to provide the needed units and
whether buyers are able to pay for them.
The housing needs of construction workers are often temporary.
Many workers live in mobile home parks (often bringing their own
trailers or campers), rooming houses, or motels for the duration
of the construction project. The housing demand of the permanent
operating work force is basically a function of:
x^ ^\
• the need for housing (normally based on household size)
• preference for different types of units (mobile homes,
single family units or apartments)
• income levels and willingness to pay
• ability to secure financing
^ S
Although the income levels of most uranium mine and mill
employees are high enough to initially qualify them for a
mortgage, the uranium-mining industry is known for the mobility
of its work force. This can cause difficulty in providing
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adequate credit and employment histories for loan applications.
Conservative lending institutions frequently do not look upon
these newcomers as good risks and question the probable period of
residence of the applicant and the strength of local housing
demand after completion of the project.
Even when demand appears adequate to insure increased housing
production, a number of other factors may constrain the supply of
needed housing units. These include:
UNAVAILABILITY OF MORTAGE CREDIT - Small local economies
cannot normally generate the rate of capital formation
required to meet the needs for new housing mortgages
without importing capital from outside financial centers.
The institutional constraints encountered include the
absence of effective correspondent banking relationships,
the inability to have access to the secondary mortgage
market due to the relatively small size of the mortgage
packages, and the rejection of secondary mortgage packages
as too risky and/or too difficult to evaluate and
supervise.
LIMITATIONS ON LOCAL ENTREPRENEURIAL SKILLS - In some
instances, there is no active construction industry prior
to initiation of the uranium project.
UNAVAILABILITY OR HIGH COST OF SKILLED CONSTRUCTION LABOR
Whatever local construction force exists may be bid away
from the housing industry by the uranium project.
DIFFICULTIES IN ACQUIRING SUITABLE LAND - This is 'hampered
in coastal areas by environmental constraints and
competition from other land users (e.g., resorts), in many
semi-rural eastern areas by large lot zoning, in
Appalachia by terrain and monopolistic land ownership
patterns and in the Rocky Mountains by public land
ownership.
SHORT PAY-OUT PERIODS FOR RENTAL UNITS - Where peak work
forces create temporary housing demand, rapid amortization
of developers1 and creditors' investments may lead to
extremely high income requirements for rental units and
mobile home sites. .
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ABNORMAL FRONT-END RISKS - Where a single -project is
responsible for a large proportion of the local housing
demand (e.g., a large power plant in a small community),
developers and construction lenders may feel that their
vulnerability to project delays (e.g., due to
environmental litigation) is unacceptable. Lenders in
particular may refuse to take part in housing developments
until project construction is actually underway.
EXCESSIVE FRONT-END COSTS - Factors limiting land
availability may also increase costs of roads, utilities,
etc. Also, local governments facing financial
difficulties with front-end financing may respond by
shifting a portion of the burden to private developers in
the form of higher utility tap fees, requirements for
cost-sharing on roads and utilities, and requirements for
school and park land dedications.
Because of these difficulties and the problems of employee
recruitment and retention, housing has become an area where
industries have actively intervened. Activities range from (1)
attempting to remove the constraints described (i.e.,
guaranteeing the sale or rental of housing constructed in advance
of the project, lease-purchase arrangements for employees, and
recruiting outside developers) to (2) acting as developers of
bunkhouses, subdivisions and mobile home parks to (3) providing
housing subsidies. The extent to which industry becomes involved
varies from company to company and from region to region.
5.5.2
Commercial Development
In addition to the housing supply and demand difficulties, the
host community can experience other related problems.. If there
are no effective controls on the pattern of development (i.e.,
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zoning and subdivisions regulations), "rural" sprawl can develop.
The difficulties which may be encountered when sprawl development
occurs include:
• HEALTH PROBLEMS — Adherence to and enforcement of the
health standards associated with water and liquid waste
treatment facilities may be neglected.
• INCREASED COST OF PROVIDING PUBLIC SERVICES - Water and
sewer lines must be extended to fringe areas, and
additional police and fire protection may be difficult to
provide.
• SPRAWLED DEVELOPMENT LIKELY TO REMAIN - The pattern of
development which first begins in response to the stresses
of growth is the one which is likely to continue after
growth stabilizes.
J
Even in the absence of formal controls/ communities can exert
some degree of authority over growth patterns by carefully
choosing when and where to expand utilities and services.
Many of the same financial considerations and constraints can be
applied to the problems of commercial development. In small
rural areas there is often a lack of local entrepreneurial skill.
Furthermore, local lending institutions do not always have the
well-developed correspondent banking relationships required to
import substantial amounts of outside capital. Outside lenders,
as well as local ones, may not be willing to lend money for
commercial development when there is substantial uncertainty
about the timing and duration of the expected development. Large
chain operations (e.g., K—Mart and Safeway) have their own
criteria for opening stores in an expected'growth area.
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Potential actions to enhance opportunities and/or mitigate
problems include:
Community actions
• Industrial revenue bonds to improve industrial and
commercial sectors' access to credit
• Publicity (e.g., Chamber of Commerce activities)
concerning the need for new entrepreneurial activity in
local services and housing
• Public housing programs (e.g., HUD Section 12)
• Expanded efforts by local financial institutions to have
access to secondary credit markets and develop
correspondent banking relationships
Industry actions
• Recruitment of outside housing developers
• Guarantees (underwriting) of credit for housing
development started in anticipation of the arrival of
construction workers
• Purchase of land for housing development prior to
announcement of energy development intentions (to prevent
land speculation)
• Acting as housing developers, especially for temporary
construction housing
State/federal actions
• Increasing fund allocations and accessibility of FHA
mortgage guarantees in impacted areas
For more information see:
Data on housing demand
• Mountain West Research, Inc. Construction Worker Profile.
Washington, D.C.: Old West Regional Commission, 1976.
• Wyoming Department of Economic Planning and Development,
ongoing housing—market projections.
5-36
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Examples of previous industry involvement in housing
• Rocky Mountain Energy Company underwrote the construction
of 32 homes in a new subdivision in Douglas, Wyoming
• Gulf Oil Company plans to develop a plat of land in
Grants, New Mexico. Actual construction will be done by
independent contractors. At least one—third of the homes
must be offered to general public.
• Phillips Petroleum Company anticipates the development of
a Planned Unit Development (PUD) in Thoreau, New Mexico,
near Grants. Plans include single family lots,
multi—family units, trailer spaces, a park, commercial
areas, and a KOA—type park for campers and motor homes to
serve temporary construction workers.
5.6
Socio-Cuitural and Political Changes
Uranium development projects can have significant social,
cultural and political effects on the host community. These
changes include varying impacts to diverse parties of interest
(e.g., federal, state, or local governmental entities, industry
and commercial interests, and the general public). Impacts on
long-time residents have included loss of political power
traditionally dominated by ranching or farming interests and
perceived decline in personal safety. Effects on newcomers have
included perceived .rejection by long-time residents, strong
feelings of alienation, and stress reactions by unemployed mates.
Table 5—8 provides an example of some of the "before" and "after"
sociocultural changes expected as a consequence of uranium and
other resource development in Converse County, Wyoming.
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Indicators
Characteristics of Society—1975
Characteristics of Society—1985
Social Structure
Economy
Technology
Occupational structure
Regulates distribution
of power
Adjudicates conflict
and claims
Culture
Expressive sycbolism
Institutions
family
Education
Communities
SUMMARX
Total employment—3,150
Balanced economic bane-
Agriculture is 39Z of basic employment
Mining and processing is 33Z
Retired individuals comprise 32.4* of
population
Expanding Job opportunities within the
county since 1970; gain of population since
1970 vs. a loss of population ia the 1960's
Agriculture technology fairly advanced;
large power plant and several mines
Rancher S blue collar workers roughly
equally significant
Rancher dominated counties (the 3 county
commissioners are ranchers); county vnich
has traditionally bean intiplanning is now
establishing and stressing acre conprehen-
slve planning aachanisnis
Legislature is rural dominated; county
government deals with few conflicts, largely
between revenues (taxes) and expenditures
(service requirements)
Protestant Christian values—United Method-
ist, Baptist, Episcopal—37.5X of county
population are church adherents (the
national average Is 501)
£aphasis on independence and self-reliance—
801 of the fares (i ranches) are owner-
occupied (the national average is 62%) ; 20Z
of all the work force is self-employed (the
national average is 112)
Attitude of peraanence—attachment to the
area Is high; (76Z of 1970 residents had
lived ia county for S years or more)
1972 divorce rate—4.26/1,000 population,
an increase in chu 1970 race of 3.03/1,000
Low dropout rate of 7.2Z (the national
average is 2SZ)
Two very snail service canter tovns; high
proportion of pemanent housing
Traditionally an agrarian society, recent
increase in the number of ainers & con-
struction workers; county now dominated
by ranchers and employees of the energy
Industry; includes service and governmental
components
Total employment—6 ,600
Single industry economic base-
Agriculture is now 15Z of basic employment
Mining and processing is now 731
Job opportunities will continue to draw aew
residents, they may also help stem out
migration of young people from the area
Advanced mining and processing technology;
more specialized; more diversified and
sophisticated; improved technical, educa-
tional and professional services in the area
Blue collar dominated
Changes in occupational structure, technol-
ogy, and economy all aust be dealt vlth and
will change constituencies; urban centers
will be larger S aore cocolex, will require
sore planning and administration
Hew conflicts: newcomer vs. old tiaer, aore
urban vs. rural strain; interindustry 4
environmental conflicts aore coanon; more
concern with 4 need for Federal intervention
with aore urbanization; unions probably aore
of issue & possibly a political force
More emphasis on political,
economic groups
social, and
.Presence of a large population who view
themselves as temporary
Dropout rate may coma closer to the national
average as the county becomes aore industrial
Growth, more diversity in the two service
centers, increase in the proportion of tem-
porary housing; possible degradation of ser-
vices and overcrowding to accompany rapid
.SXSXtfc
More urban, complex society, including new
extractive & processing components: county
now dominated by the energy industry
SOURCE:
NRG, NUR2G 0129
January, 1977
Table 5-8
\w Indicators of Societal Change - Converse County, Wyoming
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5.6.1
Socio-Cultural Changes
Often the integration of newcomers and native populations has
been a major problem. This problem is particularly difficult
during aarly development stages when the construction work force
arrives and the two different cultures confront each other. In
later development stagest the construction work force is replaced
by the permanent mining and milling work force and their
families. These new permanent residents may be different than
the old timers, but ideally, a mutual accommodation occurs.
Those families that permanently settle in the community (e.g.,
buying houses, raising children) eventually become a part of the
social, political, religious, cultural and civic life of the
community.
Newcomers may have different values and life-styles than the
existing population. For example, ranchers may not view
leisure—time activities in the same way as miners or construction
workers. The newcomers may desire baseball and Softball fields,
bowling alleys, and the use of farm land and open space for
hunting and fishing. These desires might be in conflict with the
ranchers' common view that land is to be conserved and valued for
production of food, livestock and personal hunting.
Denominational affiliation and church attendance may also change.
Cultural differences may be particularly important considerations
when uranium development takes place near or on Indian lands and
where Indians may account for a significant portion of the work
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force. Many tribes have varying beliefs and customs that play a
significant role in future relationships with other employees and
with the uranium companies. For example, in some cases, attempts
at hiring Indians for an underground mining operation would be
futile. Age-old beliefs keep some tribal members from going
underground. Because of strong tribal and family ties, many
Indians prefer to live on the reservations and commute to work.
Cultural differences are very important considerations in any
active recruitment program for Indians.
5.6.2
Political and Demographic Changes
One of the more visible changes that is likely to occur in the
community will be the redirection of the social, and political
leadership. Traditionally, rural communities have been dominated
by the ranchers or farmers. As more white—collar and blue—collar
workers move into the community and become active in local
affairs, they often challenge the traditional leadership. They
may hold different views concerning energy development of all
types, environmental issues or planning and zoning. These
differences will slowly be reconciled and eventually community
leadership may be held jointly.
Other expected changes include a shift from an older population
to a younger one and an increase in the standard of living for
many employees. Often rural communities have an older
population, with many of the ranchers having retired to town.
Because uranium development increases job opportunities, young
5-40
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people are likely to remain instead of moving out after high
school graduation. In addition, new miners and mill employees
moving into the area are apt to be in their late 20 's or early
30 's. The retired population may not decrease, but their size
relative to the other segments may change drastically. The
uranium industry's wages will be significantly higher than other
available positions in the community. This will, in effect,
drive up the average wage scale and, perhaps, the cost of living.
Elderly residents who live on fixed incomes may be adversely
affected by higher rents, food prices, taxes, etc.
Additional sources of information on social change include:
• Davidson, Conna. Social Impact Prevention and Human
Service Needs in the Energy Impacted Areas of New Mexico:
Recommendations to the State Government. Santa Fe: State
of New iMexico Health and Social Services Planning
Department, 1977.
• Uhlmann, Julie M., et al. A Study of Two Wyoming
Communities Undergoing the Initial Effects of Energy
Resource Development in the Powder River Basin: Buffalo
and Douglas, Wyoming — 1975. Laramie: University of
Wyoming, 1976.
5.7
Other Potential Conflicts
Other potentially adverse impacts may occur as a result of
conflicts between parties of interest and public agencies and
regulatory institutions. Many of these conflicts result from
increased competition for water, land or labor within the region.
Competition for scarce resources often results in the price of
5-41
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the resource being bid up, the supply reduced or both. Industry
and commercial developers often compete with the agricultural and
ranching sectors of the economy for land and water. This
conflict can become further complicated if land for development
includes, or is near recreation or environmentally sensitive
areas. For example, some recent wilderness area designations
have eliminated potential areas of uranium discovery.
The local markets may also be disrupted as the uranium developers
hire at high wages and attract labor from local employers.
Personal income of new uranium employees is favorably impacted,
but many business and local governmental employers are unable to
change their wage structures to compete and are without needed
help. Unless some hiring restrictions are imposed, some
teenagers may also be tempted to quit school and work for the
uranium or construction companies.
Another potential area of conflict is regulatory jurisdictions
and responsibilities in overseeing uranium developments. For
example, there are state and federal regulations regarding
tailings disposal. Some states are agreement states (i.e., they
have the authority to issue their own uranium mill licenses), but
others are not. To the extent that regulatory uncertainty
increases the uncertainty of mine or mill development, the
difficulty of mitigating each of the categories of impacts
described previously is increased. Many of these conflicts have
not been formally addressed.
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5.8
Contingency Planning and Monitoring Programs
The state of socioeconomic impact assessment is currently
undergoing rapid development, and more reliable forecasting
techniques will be available in the future. However, for the
present, communities and uranium firms can reduce the penalties
for inaccurate forecasting by developing contingency plans.
A community may prepare by planning for a range of likely
occurrences. Such contingencies could include alternative
capital budgets and reservation of some of the legal bonding
capacity for unforeseen events. Financial institutions might
plan for flexibility in mortgage terms, and housing developers
could design mobile home parks which could later be converted to
permanent housing. Contingency planning may be desirable in each
of four development phases:
• ANNOUNCEMENT PHASE - For example, to direct adverse
effects of speculation in land and housing.
• BUILE-DP PHASE - For example, to encourage a corresponding
build—up in local business and to time public sector
investments.
• OPERATING PHASE - To monitor changes.
• ABANDONMENT PHASE - To prepare for eventual declines in
mine/mill employment as, for example, the ore body is
depleted.
V J
5-43
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Much of the uncertainty surrounding socioeconomic impacts can be
removed by continuing monitoring programs. Such monitoring
programs have only very recently been initiated to check the
accuracy of impact projections, track the effectiveness of
mitigative programs and provide a sound basis for mid—program
corrections. These monitoring programs are not only very useful
in providing more data for general forecasting use, but also can
guide the specific project in timely implementation of contingent
plans. An effective ongoing monitoring program will help bridge
the gap between prediction and actual occurrence and thus permit
adjustment of mitigative efforts to changing circumstances.
5-44
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CHAPTER 5
References
DRI. work performed under subcontract to
Stone & Webster Engineering Corporation, 1978.
EREA. Statistical Data of the Uranium Industry.
GJO—100—76. Grand Junction, Colorado: ERDA, January
1976. .
Moore, K.D. Financing Options for Communities Near
Large Energy Developments. Denver, Colorado: Rocky
Mountain Center on Environment, July 1976.
NRC. Draft Environmental Statement Related to Operation
of Bear Creek Prelect Rocky Mountain Energy Company,
NUREG-0129, January 1977.
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Bibliography
DIRECT IMPACTS ON EMPLOYMENT AND INCOME
Mountain West Research, Inc. Construction Worker
Profile. Washington, B.C.: Old West Regional
Commission, 1976. Extensive survey of construction
workers and projects in nine western communities and
14 major construction sites.
University of Wyoming, Agricultural Experiment Station.
Profile of a Rural Area Work Force: The Wyoming Uranium
Industry. Research Journal 79. Laramie: University of
Wyoming, January 1974. Detailed profile of the
existing Wyoming uranium industry work force.
INDIRECT AND INDUCED IMPACTS ON EMPLOYMENT AND INCOME
Hirsch, W.Z. Urban Economic Analysis. New York:
McGraw-Hill, 1973. Descriptions and comparisons of
strengths and weaknesses of alternative analytical
techniques.
Miernyk, William H. The Elements of Input-Output
Analysis. New York: Random House, T965. Detailed
description of input—output models.
Tiebout, Charles M. The Community Economic Base Study.
New York: Committee for Economic Development,
December 1962. General formulation of the economic
base concept and examples of simple procedures.
POPULATION CHANGES
The Navajo Nation. Office of Program Development. The
Nava1o Economic/Demographic Model. Window Rock,
Arizona: The Navajo Nation, January 1976. Available
from Office of the State Planning Coordinator, Salt
Lake City, Utah. Example of sophisticated
economic/demographic model using cohort survival
analysis.
Tennessee Valley Authority. Final Environmental
Statement Morton Ranch Uranium Mining. Chattanooga,
Tennessee: TVA, January 1976. Description of
socioeconomic impacts (including labor participation)
of the mining of uranium deposits at Morton Ranch in
Converse County, Wyoming.
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POPULATION CHANGES, Continued
U.S. Nuclear Regulatory Commission. Draft
Environmental Statement Rocky Mountain Energy Company's
Bear Creek Project. Washington, D.C.: U.S. Government
Printing Office, January 1977. Description of
socieconomic impacts (including characteristics of the
incoming work force) of a uranium mine—mill operation
in Bear Creek, Wyoming.
Williams, David, et al. Impacts of the Proposed Peabody
Rochalle Coal Mine. Reston, Virginia: USGS, 1978.
Example of community weighting techniques (combing
"hard" data such as miles from mine with "soft" data
such as community attractiveness) for determining
population settlement patterns.
Schmitz, Steve, et al. Growth Monitoring System Project
Report for State Planning and Management Region XI.
Rifle: Colorado West Area Council of Governments, 1977.
Example of Delphi technique (interviewing knowledgeable
local residents) for determining population settlement
patterns.
Chalmers, James A. "The Role of Spatial Relationships
in Assessing the Social and Economic Impacts of Large
Scale Construction Projects." Natural Resources
Journal, April 1977, pp. 209-222. Example of a
modified gravity model (using only easily obtained,
quantified information) to estimate population
settlement patterns.
PUBLIC SERVICES AND PUBLIC FINANCE
Gilmore, John, et al. (Denver Research Institute).
Impacts of Western Energy Development. Washington,
D.C.: The President's Council on Environmental Quality,
1978. Description and validation of fiscal impact
models and methodology on selected Coloado and Utah
communities.
Muller, Thomas. Fiscal Impacts of Land Development.
Washington, D.C.: The Urban Institute, 1972. . Summary
of alternative approaches and detailed bibliography for
fiscal impact analysis.
Real Estate Research Corporation. Costs of Sprawl.
Washington, D.C.: U.S. Government Printing Office,
1974. Summary of detailed cost analyses and
bibliography for alternative development patterns.
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PUBLIC SERVICES AND PUBLIC FINANCES, Continued
Briscoe, Maphis, Murray and Lament, Inc. Action
Handbook for Small Conununitiss Facing Sapid Growth.
Denver: Environmental . Protection Agency, 1978.
Planning processes and additional sources of
information for the small community.
Centaur Management Consultants, Inc. Assistance for
Energy Developers: A Negotiating Guide for Small
Communities. Washington, D.C.: Energy Research and
Development Administration, 1977. Alternative roles
for industry, written primarily for public officials in
potentially affected communities.
Moore, K.D., et al. (Denver Research Institute).
Mitigating Adverse Socieconomic Impacts of Energy
Development; Present Programs and Mechanisms and
Further Policy Options. Washington, D.C.: U.S.
Department of Energy, 1977. Description and analysis
of existing federal, state, and industry programs
dealing ' with socioeconomic impacts of energy
development.
HOUSING AND COMMERCIAL DEVELOPMENT
Metz, Dr. William C. Residential Aspects of Coal
Development. Pittsburgh: Westinghouse Electric
Corporation Environmental Systems Department, for
American Institute of Planners Conference, October
10—12, 1977. Examples and methods of company
initiatives to provide adequate housing to miners.
Mountain West Research, Inc. Construction Worker
Profile. Washington, D.C.: Old West Regional
Commission, 1976. Extensive survey of construction
workers and projects in nine western communities and
fourteen major construction sites.
SOCIO-CULTURAL AND POLITICAL CHANGES
Davidson, Donna. Social Impact Prevention and Human
Service Needs in the Energy Impacted Area of New
Mexico: Recommendations to the State Government.
Santa Fe: State of New Mexico Health and Social
Services Planning Department, 1977. Description of
problem areas and subsequent recommendations for human
service delivery systems in an energy impacted area.
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SOCIO-CULTURAL AND POLITICAL CHANGES, Continued
Gilmore, John S. and Mary K. Duff. Egom Town Growth
Management: A Case Study of Rock Springs—Green River,
Wyoming. Boulder: Westview Press, 1975. The future of
the mining and construction boom in the two communities
were analyzed and projected. Description and
categorization of problems in two impacted communities
and suggestions for new legislation/institutions.
Uhlmann, Julie M., et al. A Study of Two Wyoming
Communities Undergoing the Initial Effects of Energy
Resource Development in the Powder River Easin: Buffalo
and Douglas, Wyoming—-1975. Laramie: University of
Wyoming, 1976. Comparison of characteristics and
attitudes of longtime residents to newcomers in two
rural Wyoming communities.
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GLOSSARY
-------
Glossary
Adit - A horizontal or nearly horizontal passage driven from the
surface for the working or unwatering of a mine.
Amendment - A material added to soil to improve its capability
for supporting plant growth, particularly for reclamation.
Autogenous Grinding - Grinding ore by tumbling the material in a
revolving cylinder without balls or rods. The ore itself acts as
the grinding media.
Btu - British thermal unit.
Beneficiation - The dressing or processing of ores for the
purpose of regulating the size of a desired product, removing
unwanted constituents, or improving the quality, purity or assay
grade of a desired product.
Beta Particle - A positively or negatively charged particle
having the mass of an electron which is emitted from a nucleus
during radioactive decay.
Breeder Reactor - A reactor which generates more fissile material
than it consumes.
CANDU - Canadian Natural Uranium Reactor.
CSMRI - Colorado School of Mines Research Institute.
Caving - An unsupported stoping method in which the hanging wall
in the stop.ed-out area is allowed, or sometimes forced, to
collapse and close the opening..
Circuit - The path of.material through the mill.
Countercurrent Decantation - The clarification of liquor and the
densification of tailings by the use of several thickeners in
series. The liquor flows in the opposite direction from the
solids.
Curie - A unit quantity of radioactive material in which
3.7 x IQio disintegrations per second occur.
DES. - Draft Environmental Statement.
Dose - An amount of radiation absorbed.
Dose Commitment - The total dose that an organism is expected to
receive in its lifetime from a given quantity of radioactive
material deposited in the body.
G-1
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Dose Equivalent - The product of absorbed dose in rads and
certain modifying factors. It expresses all radiation on a
common scale for calculating the effective absorbed dose.
DRI — Denver Research Institute.
Enrichment - The process of increasing the percentage of the
fissionable isotope zasij above that contained in natural uranium,
usually to 2—4 percent for use as reactor fuel.
Extract ant - The active organic reagent which forms an
extractable complex with the dissolved uranium.
FRP - Fiber reinforced polyester, a fiberglass construction
material.
Face - The solid surface of the unbroken rock at the advancing
end of an underground working.
Fertile - Able to be converted to fissionable material.
Fissile Material - Atoms such as zasu or 239Pu that fission upon
absorption of a low energy neutron (Keeny et al., 1977) .
Fission - The splitting of an atomic nucleus with the release of
energy.
Flocculants - Agents that induce or promote flocculation or
aggregation of solids.
Forward Costs - The Department of Energy, through the NURE
program, provides estimates of reserves and resources for U30a at
various dollar-per-pound forward costs. The estimates are ranked
by cost of recovery termed forward cost. Forward costs are
operating and capital costs that are not yet incurred at the time
the estimate is made. Past expenditures for such items as
property acquisition, exploration,- mine development, return on
investment, or profit are not included.
The forward costs are not production costs or market selling
price. Each forward cost category is used as a maximum cutoff
although average costs may be less overall for each reserve or
resource estimate (Keeny et al., 1977).
Forward operating costs include direct and indirect mining costs,
haulage, royalty and milling costs. Forward capital costs
include cost estimates for the, mill, mine plant construction,
additional mine development and equipment (Meehan, 1977).
The market price to stimulate full production of a resource base
may be significantly higher than the estimated cost of producing
that resource. Many recent contracts in the early 1980's are $40
to $65 per Ib in year-of-delivery dollars. In part, the price
difference is due to low-grade ore and relatively high-price
recovery projects. New underground mines operating at greater
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depths and new surface mines extracting lower grade ore are
examples of high cost projects. Recovery from mill tailings ' and
mined-out areas are relatively high cost also.
GPP - Gallons per day.
GPM - Gallons per minute.
Gamma Radiation - Short wavelength electromagnetic radiation
emitted when an excited nucleus drops to its ground state.
Half-Life - The amount of time required for one half of the
amount of radioactive material present to decay.
Haulageway - The gangway, entry or tunnel through which mine cars
are moved.
In Situ - In a natural or original position.
Injection Well - For a solution mining operation, a lined hole
placed in the ore body for the purpose of introducing the
leaching solution.
Ion Exchange - Reversible exchange of ions contained in a resin
for different ions in solution without destruction of the resin.
Ion Exchange Columns - A vessel packed with beads of resin.
KWHR - Kilowatt-hour.
Leaching - Extracting a soluble compound from an ore by
selectively dissolving it in a suitable solvent.
Light Water Reactor (LWR) - A nuclear reactor that uses ordinary
water as a coolant to transfer heat from the fissioning uranium
to a staam turbine and employs slightly enriched uranium as fuel
(Kaeny, at al., 1977).
LWR Natural Uranium Requirements - The 1000 MW(e) LWR requires
about 550 to 625 short tons of U308 for initial fuel loading and
about 200 tons for annual refueling. The U30a is processed and
enriched slightly for fuel rod assemblies which fuel the reactor.
(NRC, GESMO, 1976, pg IV F-1.)
Liquor - Liquid.
Lixiviant - Leaching solution.
Low Grade Ore - Ore which has a low content of the metal for
which it is mined.
14 CP - Thousand cubic feet. -
MT/D - Metric tons per day.
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MW (e) - Megawatts of" electricity.
Monitor Well - . For. a solution mining operation, a hole
strategically located in the ore body, aguifer, etc., for the
purpose of detecting escaping leaching solutions.
Muck - Unconsolidated rock.
Mudstone Splits.- Localized mudstone interbedding between two
masses of sandstone.
Nuclear Fuel Cycle - The nuclear fuel cycle for the Light-Water
Reactor shown in Figure G—1 depicts the operations that occur
before and after fissioning of fuel at the reactor. In the
figure the steps connected by a solid line are currently (1978)
operational. The steps connected by a dotted line are yet to be
implemented pending government resolution of its policy on
reprocessing, storage, and disposal of spent fuel.
The nuclear fuel cycle consists of several steps:
• EXTRACTION - removing the ore (uranium) from the ground,
separating uranium from the waste, and converting the
uranium to a chemically stable oxide (nominally U308).
« CONVERSION - changing the 0308 to a fluoride (UF6), which
is a solid at room temperature but becomes a gas at
slightly elevated temperatures, prior to enrichment.
• ENRICHMENT - concentrating the fissionable isotope (23SU)
of uranium from the naturally occurring 0.7% to 2—4fo for
use in reactors for power generation.
• FABRICATION - converting the enriched uranium fluoride to
uranium dioxide (U02) f. forming it into pellets, and
encasing the pellets in tubes (rods) that are assembled
into fuel bundles for use in power generating reactors.
• NUCLEAR POWER GENERATION - using the heat resulting from
the fissioning 6f uranium and plutonium for generating
steam for the turbines.
• SPENT FUEL REPROCESSING - chemical separation of
fissionable and: fertile values (235U, 238U, Pu) from
fission products (waste), with concurrent separation of
uranium from plutonium.
• WASTE MANAGEMENT - storage 'of fission products and low-
level wastes resulting from reprocessing in a manner that
is safe and no threat to health or environment.
Source: NRC, NUREG-0403, 1977.
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Overburden/SpoiI,
Minewater, Disposal
>|0re Stockpi les
Radioactive TaiI ings Waste
Storage/Disposal
Conversion to
Uranium Dioxide
Fuel
Preparation
Plutoruun
Fuel
Fabrication
Fresh Core
Reactor
Spent Core
- Full Cycli Stift Cuireitlf
Opinlleml
-- Steps Cuniatlf ttoMipluiated
rifldini OpinlUn ol l«p(actiiln|
Pilots u< ippititl •(
ti III fu«l.
• *«r f'" leicUf
Reactor Site
Spent Fuel Storage
Shipping
High-Level Wastes
Low and Intermediate-Level Wastes
SOURCE: Adapted from NRC, DES, NUREG-0403
Figure G-1
The Light Water Reactor Fuel Cycle
AFR* Spent
fuel Storage
-••Reprocess ing I—
I
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The extraction' step also 'shows the spoil material produced in
mining and the tailings residue remaining after milling
(conversion of ore to U.308 concentrate) . The concentrate is
called "yellowcake" and is about 75 percent uranium. The largest
portion of the ore (feed for the mill) remaining as tailings is
depleted in uranium but contains radium 226 and its long half
life parent thorium 230. These tailings are a source of
radon '222 emissions, which can last for thousands of years (EPA,
Technical Note, 1976). The storage and disposal of these
radioactive materials and the radiological concern about them are
discussed in detail in Chapter 4.
The NRC, Draft Environmental Statement related to the operation
of Sweetwater Uranium Project, pages H-1, H-2, NUREG-0403, NEC
December 1977 provides additional details on the nuclear fuel
cycle. Also the reader is referred to Ellett, W.H.M. and
Richardson, A.C.B., Estimates of the Cancer Risk Due to Nuclear-
Electric Power Generation, 35pp, Environmental Protection Agency,
Technical Note ORP/CSD-76— 2, EPA, October 1976.
Ore Body - Generally, a solid and fairly continuous mass of ore,
which may include low-grade ore and waste as well as pay ore, but
is individualized by form or character from adjoining country
rock (Fay, b.s. Afr.). A mineral deposit that can be worked at a
profit under the existing economic conditions.
PPM - Parts per million parts^
PVC - Polyvinyl chloride, a plastic - construction material.
Pathway - Any specific process or combination of processes
whereby a material is transported from its source to a
destination.
Pedogenic - Relating to the soil.
Phreatic Surface - The elevation at' which the pressure in the
water is zero with respect to- the atmosphere.
Porosity - The ratio of the volume of interstices in a material
the volume of material.
Portal - Any entrance to a mine.
., ••••_ -.i' •-.-'• [. . ' '
Pulp - A mixture of solids and leaching solution
Rad^ -'•' A dose of ionizing radiation equal to 0.01 joules per
kilogram of irradiated material.
Rkinoutv- In— cloud scavenging of aerosol particles by ice
crystals-.
Recovery Well - For a solution mining operation, a lined hole
placed in the ore body for the purpose of removing the leaching
solution which contains dissolved uranium.
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Refractory Ore - Ore which.is difficult to treat for recovery of
the valuable substances. ,".'.„
gem - (Roentgen Equivalent .Man) A special unit of dose
equivalent, in reins, numerically equal to the absorbed dose, in
rads, multiplied by modifying factors..
Roentgen - The special unit of exposure. One roentgen equals
2.58 x 10* coulomb per kilogram of air.
Reprocessing - The process of,.recovery of uranium and plutonium
from spent fuel.
Reserves - For uranium those resources that , are known in
location, quantity and quality and that are recoverable below a
specified cost using currently available technologies (Keeny,
et al., 1977) . . . . ,-
Resources - Deposits that may be known to.exist, but not in such
quantity or state as to be economically recoverable by present
technologies, or those that are unidentified but suspected or
probable on the basis of indirect evidence (Keeny, et al^ 1977).
"Probable" Potential Resources - Those estimated to occur in
known productive uranium districts:. . .
1. In extensions of known deposits, or
2. In undiscovered deposits within known geologic
trends or areas of mineralization.
"Possible" Potential Resources - Those estimated, to" occur in
undiscovered or partly defined deposits in formation . or
geologic settings productive elsewhere within the same
geologic province. . . .
"Speculative" Potential Resources - Those estimated to occur
in undiscovered or partly defined deposits: ' ". '
1. In formations or- geologic settings not previously
productive within a productive geologic -:"province,
or
2. Within a geologic province not previously
productive. . . , - .
"Productive" infers that -past production plus known reserves
exceed 10 tons U308. ., 4 "
Saltation - The process of soil transport where.a wind-blown, soil
particle impacts the ground and dislodges other soil particles.
Semi-Autogenous Grinding - Grinding ore by., tumbling the material
in a revolving cylinder with fewer steel balls or r'dds" thi|i . in
typical tall or rod mills.. .. .... . ...... .;; *'..:•;.
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Separative Work - Work required to separate isotopes in the
enrichment process, measured in Separative Work Units (SWU's).
It takes about 100,000 SWU's per'year to keep a 1000 MW(e) LWR
:': 6 per at ing*: "•
Shaft - A vertical or inclined excavation of limited area
compared with its depth/ > made ""for ;' finding ore, mining ore,
raising water, ore, rock, hoisting or lowering men and material
or ventilating underground workings.
Skip - A guided hopper, usually rectangular, used in vertical or
inclined •shafts for hoistiri'g rock, .men or materials.
„- *• . •'" •
Solution Mining - The technique of•/dissolving minerals in situ by
injecting a suitable leaching solution into the ore body and
recovering the metal bearing liquors in a pattern of wells.
Solvent Extraction - Selective transfer of metal salts from
aqueous solutions- to- an:immiscible organic liquid.
Somatic - An adjective pertaining to the body.
Source Term - The quantity of material which is released from a
given source per unit time. The source term may include a
qualitative description of the material released, as well as the
geometry of the release.
Sparging - In this context, bubbling gas into liquid or a liquid-
solid mixture.
Spent Fuel - The fuel removed from a reactor after several years
of generating power. Spent fuel contains radioactive waste
materials, unburned uranium and plutonium (Keeny et al., 1977).
Sto.pe - An underground opening from which ore is being excavated
in a series of steps.
Stoping - The act of excavating ore by means of a series of
horizontal, vertical or inclined workings in veins or large,
irregular bodies of ore, or by rooms in a flat deposit. Includes
the breaking and removal of ore from underground openings, except
those driven for exploration and development.
Stripping Ratio - The unit amount of waste that must be removed
to gain access to a similar unit amount of ore.
Student "t" Test - A common statistical procedure used to test
the difference between the means of two sets of numbers.
Sump - That portion of the shaft below the normal winding level
which is used for the collection of water for pumping.
Surface Mining - Mining in surface excavations.
SWEC - Stone & Webster Engineering Corporation.
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TPD - Tons per day-., . ,...-. "' , . < •.,', .,»'.;.
Tails Assay - The percentage of the isotope -zssg ±n. the-uranium
remaining after production of enriched uranium. The., percentage
is usually less than 0.3 percent.
Tunnel - A horizontal" or nearly-horizontal uhdergrbuneliyp"a;ssage
that is open to the atmosphere a^t'both ends. \.,i
Uraniferous - Uranium bearing.
Uranium Oxide (U30fl) - The most common oxide of uranium in ore.
The amount of elemental uranium in raw" material (in terms of
black oxide equivalent-, U^9a) may be determined:by mul-^L-plying
the U30a content by 0.85., ..;,,• . ;; . ;' . ";'C '*"'• "•./:
Vat Leaching - Leaching in troughs without mechanical agitation.
Washout - Scavenging of aerosol particle^ by fail-i.ng raindrops or
ice crystals.
Well Field - Por a solution mining operation, the area which
encompasses the injection and recovery welds. V"
Yellowcake - The uranium concentrate.: produced by uranium mills.
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