U.S. GEOLOGICAL SURVEY CIRCULAR 994 

Uranium Resource Assessment by 

the Geological Survey: 

Methodology and Plan to Update 

the National Resource Base 

Uranium Resource Assessment by 

the Geological Survey: 

Methodology and Plan to Update 

the National Resource Base 

By Warren I. Finch and Richard B. McCammon 

U.S. GEOLOGICAL SURVEY CIRCULAR 994 

Work done in cooperation with the Energy Information 

Administration, U.S. Department of Energy 

Describes a new method to estimate undiscovered uranium 

endowment and the plan to conduct assessments necessary for a 

sound, current resource picture 

7987 
Department of the Interior 

DONALD PAUL HODEL, Secretary 

U.S. Geological Survey 

Dallas L. Peck, Director 

Library of Congress Cataloging-in-Publication Data 

Finch, Warren Irvin, 1924-

Uranium resource assessment by the Geological Survey. 

(U.S. Geological Survey circular; 994) 

Bibliography: p. 

Supt. of Docs. no.: I 19.4/2:994 

1. Uranium ores-United States. 2. Mine surveying. I. McCammon, Richard B. II. Title. 

III. Series: Geological Survey circular; 994. 

QE75.C5 no. 994 557.3 s 86-600418 

[TN490. U7] [553.4 '932 '0973] 

Free on application to the Books and Open-File Reports Section, U.S. Geological Survey 

Federal Center, Box 25425, Denver, CO 80225 
CONTENTS 

Page 

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Chronology of assessing potential uranium resources 2 

Terminology of resource reporting . . . . . . . . . . . . . . 2 

National uranium resource assessment responsibilities 2 

Purpose of this report . . . . . . . . . . . . . . . . . . . . . . . . 3 

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Standard NURE method . . . . . . . . . . . . . . . . . . . . . 4 

Deposit-size-frequency method, a modification of the 

standard NURE method . . . . . . . . . . . . . . . . . . . . 5 

The assessment procedure . . . . . . . . . . . . . . . . . . . . . . . . 7 

Geologic favorability . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Control area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

Development of grade-tonnage distributions for control areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

Development of deposit-size-frequency data . . . . . . 11 

Elicitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Calculation of the estimate . . . . . . . . . . . . . . . . . . . . 11 

Page 

The assessment procedure-Continued 

Review process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Comparison of the two methods . . . . . . . . . . . . . . . . . . . 11 

The Colville-Okanogan study area . . . . . . . . . . . . . . 12 

Recognition criteria for young organic-rich 

uranium deposits by J. K. Otton . . . . . . . . . . 12 

Description of the Lake Gillette proto-control 

area for young organic-rich uranium deposits 

by J. K. Otton . . . . . . . . . . . . . . . . . . . . . . . . . 13 

Estimate by the Standard NURE method . . . . . . . 13 

Estimate by the deposit-size-frequency method . . . 15 

Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

Reporting of endowment and integration into the National 

resource base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

Strategy to update the National uranium endowment 

estimates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

International nuclear energy minerals information . . . 18 

References cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

Appendix A-Memorandum of Understanding . . . . . . . 23 

ILLUSTRATIONS 

Page 

FIGURE 1. Correlation diagram for uranium resource terminology used by DOE, DOl, and NEA/IAEA . . . . . . . . . . . 3 

2. Comparison ofF of the standard NURE method with the nJ Ac of the deposit-size-frequency method . . . 6 

3. Elicitation summary form for the deposit-size-frequency method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

4. Grade-tonnage curves for the Ambrosia Lake control area, New Mexico . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

5. Map showing the Colville-Okanogan favorable area and Lake Gillette proto-control area in the Sandpoint and 

Spokane 2° NTMS quadrangles, Washington, Idaho, and Montana . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

6. Uranium endowment data form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

7. Principal surficial uranium deposit terranes in the conterminous United States . . . . . . . . . . . . . . . . . . . . . . . 19 

8. Map of the conterminous United States showing A-priority and B-priority quadrangles for uranium endowment estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

TABLES 

Page 

TABLE 1. A list of topics to consider for comparison with available criteria to recognize favorability for uranium . . 9 

2. Values of A, F, t, and G for the standard NURE method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

3. Values of Ac and size distribution of deposits for the deposit-size-frequency method . . . . . . . . . . . . . . . . . . . 13 

4. NTMS 2 o quadrangles in conterminous United States selected to be assessed for uranium resources by the 

U.S. Geological Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

III 
GLOSSARY 

Assessment: the economic evaluation of undiscovered resources. 

Central moments: values about the mean that are special 

mathematical expectations useful in describing, and 

mathematically manipulating, random variables. The first 

four central moments (the mean, the variance, and the third 

and fourth moments about the mean) are generally adequate 

to describe most distributions. 

Confidence: belief that the true value of a given variable lies 

within a stated interval. 

Confidence interval: a range of values, between stated upper 

and lower limits within which an actual measurement is expected to occur with a stated probability. 

Confidence limits: the probability values that bound a confidence interval. The lower and upper limits used in this report 

are 5 percent and 95 percent, respectively. 

Control area: a specific geographic area for which the uranium 

reserves, potential resources, production (if any), and geologic 

characteristics of uranium concentration are known. 

Cutoff grade: the lowest grade of mineralized material, in percent U 30 8, at a minimum specified thickness that can be 

mined. at a specified cost. 

Elicitation: the formalized discussion between a principal 

scientist and a team of experts that leads to an estimate of 

the undiscovered uranium endowment within a favorable 

area. 

Endowment: [see Uranium endowment.] 

Estimated additional resources-Category I (EAR-l, NEAl 

IAEA): refers to uranium in addition to reasonably assured 

resources (RAR) that is expected, mostly on the basis of direct 

geological evidence, to occur in extensions of well-explored 

deposits and in deposits in which geological continuity has 

been established but where specific data and measurements 

of the deposits and knowledge of their characteristics are considered to be inadequate to classify the resource as RAR. 

Estimated additional resources-Category II (EAR-II, NEAl 

IAEA): refers to uranium in addition to EAR-I that is expected to occur in deposits believed to exist in well-defined 

geological trends or areas of mineralization with known 

deposits. 

Favorable area: a geographic area in which the available data 

indicate the existence of geologic environments that were 

favorable for the concentration of uranium. 

Hypothetical resources (DOl): undiscovered resources in 

deposits that are similar to known uranium deposits and that 

may reasonably be expected to exist in the same producing 

district or region under analogous geologic conditions. 

Indicated reserves (DOl): reserves whose quantity and grade 

are calculated from data similar to that of measured reserves 

but for which data points are less adequately spaced. 

Inferred reserves (DOl): reserves whose estimates are based on 

assumed continuity beyond measured and (or) indicated 

reserves for which geologic evidence exists. 

Mean: the expected value, or the first central moment, of a probability distribution. 

Measured reserves (DOl): reserves whose quantity is computed 

from measurements revealed in outcrops, trenches, workings, 

or drill holes; grade is computed from analyses of closely 

spaced samples. 

Possible potential resources (DOE): estimates of undiscovered 

or partly defined uranium deposits in rocks or geologic 

settings productive elsewhere within the same geologic province or subprovince. 

Potential resources: the portions of the uranium endowment, 

in tons of U 30 8, that are estimated to be producible at 

selected forward costs in dollars per pound of U 30 8• 

Probability: a statistical measure, where zero is impossibility 

and one is certainty, of the likelihood that a given event will 

occur or that a specific level of a quantifiable variable will 

be attained or exceeded. 

Probable potential resources (DOE): estimates within known 

productive uranium areas that are either extensions of known 

deposits or undiscovered deposits within known geologic 

trends or areas of mineralization. 

Proto-control area: a specific geographic area for which geologic 

characteristics of the uranium concentration are known but 

data for reserves and production are too limited to qualify 

as a fully described control area. 

Reasonably assured resources (RAR, NEA/IAEA, DOE): refers 

to uranium that occurs in known mineral deposits of such 

size, grade, and configuration that it could be recovered within 

the given production cost ranges, with currently proven mining and processing technology. 

Reserves (DOE): estimated quantities of uranium in known 

deposits of such tonnage, grade, configuration, thickness, and 

depth that uranium can be recovered at, or less than, a 

specified cost using state-of-the-art mining and processing 

technologies. 

Speculative potential resources (DOE): estimated quantities in 

undiscovered or partly defined deposits in formations or 

geologic settings not previously productive within a productive geologic province or subprovince or within a geologic 

province or subprovince not previously productive. 

Resource: a concentration of naturally occurring material in 

such form and amount that economic extraction is currently or potentially feasible. 

Speculative resources (SR, NEA/IAEA): refers to uranium, in 

addition to Estimated Additional Resources-Category II, 

that is thought to exist mostly on the basis of indirect 

evidence and geological extrapolations, in deposits that could 

be discovered with existing exploration techniques. 

Speculative resources (DOl): undiscovered uranium resources 

that may occur either as known types of deposits in favorable 

areas in which no discoveries have been made or in new types 

of deposits not yet recognized for their economic potential. 

Uncertainty: the inability to specify a single value for some 

variable because of limited data or information about the 

variable. Confidence intervals are measures of uncertainty. 

Uranium deposit: a discrete uranium concentration of possible 

economic interest. 

Uranium endowment: the uranium that is estimated to occur 

in rock with a grade of at least 0.01 percent U30 8• Unconditional endowment is based on the assumption that one or 

more deposits exists in the favorable area. 

Uranium inventory: preproduction tons U30 8 at and above 

minimum grade of 0.01 percent U3

0 8 contained in discovered mineralized material. 

Variance: a measure of variability or dispersion about the mean; 

the second central moment. 

World-class deposit: a type of uranium deposit that is important in world uranium production. 
URANIUM RESOURCE ASSESSMENT BY THE GEOLOGICAL SURVEY: 

METHODOLOGY AND PLAN TO UPDATE THE NATIONAL RESOURCE BASE 

By Warren I. Finch and Richard B. McCammon 

ABSTRACT 

Based on the Memorandum of Understanding (MOU) of 

September 20, 1984, between the U.S. Geological Survey of the 

U.S. Department of Interior and the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE), 

the U.S. Geological Survey began to make estimates of the undiscovered uranium endowment of selected areas of the United 

States in 1985. A modified NURE (National Uranium Resource 

Evaluation) method will be used in place of the standard NURE 

method of the DOE that was used for the national assessment 

reported in October 1980. The modified method, here named 

the "deposit-size-frequency" (DSF) method, is presented for the 

first time, and calculations by the two methods are compared 

using an illustrative example based on preliminary estimates 

for the first area to be evaluated under the MOU. The results 

demonstrate that the estimate of the endowment using the DSF 

method is significantly larger and more uncertain than the 

estimate obtained by the NURE method. We believe that the 

DSF method produces a more realistic estimate because the 

principal factor estimated in the endowment equation is disaggregated into more parts and is more closely tied to specific 

geologic knowledge than by the NURE method. 

The DSF method consists of modifying the standard NURE 

estimation equation, U=A · F · T· G, by replacing the factors F · T 

by a single factor that represents the tonnage for the total 

number of deposits in all size classes. Use of the DSF method 

requires that the size frequency of deposits in a known or control area has been established and that the relation of the sizefrequency distribution of deposits to probable controlling 

geologic factors has been determined. Using these relations, the 

principal scientist (PS) first estimates the number and range 

of size classes and then, for each size class, estimates the lower 

limit, most likely value, and upper limit of the numbers of 

deposits in the favorable area. Once these probable estimates 

have been refined by elicitation of the PS, they are entered into the DSF equation, and the probability distribution of 

estimates of undiscovered uranium endowment is calculated using a slight modification of the program by Ford and McLaren 

(1980). 

The EIA study of the viability of the domestic uranium industry requires an annual appraisal of the U.S. uranium resource 

situation. During DOE's NURE Program, which was terminated in 1983, a thorough assessment of the Nation's resources 

1 

was completed. A comprehensive reevaluation of uranium 

resource base for the entire United States is not possible for 

each annual appraisal. A few areas are in need of future study, 

however, because of new developments in either scientific 

knowledge, industry exploration, or both. Four geologic environments have been selected for study by the U.S. Geological 

Survey in the next several years: ( 1) surficial uranium deposits 

throughout the conterminous United States, (2) uranium in 

collapse-breccia pipes in the Grand Canyon region of Arizona, 

(3) uranium in Tertiary sedimentary rocks of the Northern Great 

Plains, and (4) uranium in metamorphic rocks of the Piedmont 

province in the eastern States. 

In addition to participation in the National uranium resource 

assessment, the U.S. Geological Survey will take part in activities of the Nuclear Energy Agency of the Organization for 

Economic Cooperation and Development and those of the International Atomic Energy Agency. 

INTRODUCTION 

On September 20, 1984, the Memorandum of 

Understanding (MOU) between the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE) and the U.S. Geological 

Survey (USGS) of the U.S. Department of Interior 

(DOl) was signed. The memo "describes the implementation of an agreement for assistance from 

the USGS in the assessment of U.S. potential 

uranium resources in support of the E lA 's work 

under Public Law 97-415 (January 4, 1983) to 

develop and provide information about the viability of the domestic uranium mining and milling industry." The 1984 MOU (appendix A) is a 

continuant to the MOU between DOE and DOl 

dated November 12, 1983, that called for a plan 

to conduct research on data collected under the 

National Uranium Resource Evaluation (NURE) 

Program and to provide for continuing the assessment of the Nation's uranium resources. The 1984 
EIA/USGS MOU returned to the USGS the full 

responsibility for the studies of geology and 

resources of uranium that were abrogated by the 

Atomic Energy Act of 1946. Thus, the responsibilities for uranium resource evaluation are now 

the same as for other minerals decreed by the 

USGS Organic Act of 1889. 

CHRONOLOGY OF ASSESSING 

POTENTIAL URANIUM RESOURCES 

The three basic steps that characterize the process of assessing undiscovered uranium resources 

are: ( 1) the determination (ranking) of geologic 

favorability within an area being studied, (2) the 

subjective probabilistic estimation of undiscovered endowment of uranium in the area, and (3) the 

economic evaluation of the undiscovered endowment. Determination of geologic favorability is 

based on the process of analogy in which the characteristics of the geologic setting of an area under 

study are compared to those of settings that contain known uranium deposits. In this process, 

areas are assigned a simple ranking of either favorable or unfavorable. Areas that are known insufficiently may be designated as having uncertain 

favorability. Subjective probabilistic estimates of 

the undiscovered endowment within study areas 

are derived primarily by comparisons to the known 

deposits in what are referred to as control areas. 

The economic evaluation of the undiscovered 

uranium endowment is based on several factors 

that include grade cutoff, thickness, depth, and 

mining and milling costs. Economic evaluation 

leads to potential uranium resource (Estimated 

Additional Resources) estimates of DOE. The data 

required to support the first two steps listed 

above, the methods used in estimating undiscovered endowment, and the role of the USGS in providing estimates of the undiscovered uranium 

endowment or resources are the main topics of this 

report. 

TERMINOLOGY OF RESOURCE REPORTING 

1980; Energy Information Administration, 1985), 

NEA/IAEA (Nuclear Energy Agency and International Atomic Energy Agency, 1984), American 

Society for Testing and Materials (1983), United 

Nations (Schanz, 1975), and Canada Department 

of Energy, Mines and Resources (1977). Many 

countries use variations of one or another of these 

classifications. For the purposes of this report as 

set out in the MOU (appendix A, section E), a 

modified DOE classification using in part the 

NEA/IAEA classification will be used (fig. 1, 

DOE, 1983-current). This modification correlates 

quite closely to the classification used by the 

USGS. The terms used in figure 1 are defined in 

the glossary. If the definitions are studied carefully, one can see that each classification is based on 

actual and geologic assurance of existence. Correlations in figure 1 are in many places only approximate, especially in the zone between identified 

resources and extensions of identified resources 

into undiscovered categories. Our report is basically for guiding the estimation of the undiscovered 

uranium resource endowment, so we concentrate 

on the methodology for this purpose. Guidance for 

making economic evaluations of the different 

classes of resources is beyond the scope of our 

report. However, those interested can learn of the 

cost categories used by DOE (U.S. Department of 

Energy, 1980; Energy Information Administration, 1985) and NEA/IAEA (Nuclear Energy 

Agency and International Atomic Energy Agency, 1984) by referring to their publications. 

Endowment is defined as the amount of uranium 

in recognizable concentrations in rocks that average 0.01 percent U30 8 or more. Although the 

initial estimate of endowment is termed the conditional endowment by DOE (U.S. Department of 

Energy, 1980), we modify the equation to calculate 

unconditional endowment directly. From the unconditional endowment, one may segregate, using 

different grade cutoffs, the economic portion or 

potential uranium resources. 

NATIONAL URANIUM RESOURCE 

ASSESSMENT RESPONSIBILITIES 

Terminology used to report resources probably According to the 1984 MOU formal agreement, 

varies more for uranium than for any other mineral the determination of geologic favorability and the 

commodity. Worldwide, several major classifica- estimation of undiscovered endowment are the 

tions of economic uranium resources exist, includ- responsibility of the USGS. The economic evaluaing those of the USGS (U.S. Department of tion of the undiscovered endowment is the responInterior, 1980), DOE (U.S. Department of Energy, sibility of the EIA. These economic resource 

2 
Resource classes Agency (see Glossary for definitions) 

Possible and 

DOE (1974- Speculative 

1982) Reserves Probable Potential Resources Potential 

Resources 

DOE (1983- Reasonably Assured Resources Estimated Additional Resources Speculative 

current) (RAR) (EAR) Resources 

Identified Undiscovered 

DOl 

Measured 

I 

Indicated Inferred Reserves Hypothetical Speculative Reserves Reserves 

Estimated Additional Estimated Additional Speculative 

NEAIIAEA Reasonably Assured Resources (RAR) Resources I (EAR=I) Resources II (EAR=II) Resources (SR) 

Decreasing confidence in estimates 

FIGURE !.-Correlation of uranium resource terminology used by DOE, 1972-1982 (U.S. Department of Energy, 1980), DOE, 

1983-current (Energy Information Administration, 1985), DOl (U.S. Department of Interior, 1980), and NEA/IAEA (Nuclear 

Energy Agency/International Atomic Energy Agency, 1984). 

estimates and the reserve and production data provided by industry are reported in the "Uranium 

Industry Annual" (Energy Information Administration, 1985), a new publication that replaces the 

former annual "Statistical Data of the Uranium 

Industry" report (U.S. Department of Energy, 

1983). The determination of favorability and 

estimation of the uranium endowment for individual regions will be reported to the public in one of 

the regular USGS publications. 

PURPOSE OF THIS REPORT 

The primary purpose of this report is to describe 

the new method to be used by the USGS in assessing undiscovered uranium resources and to provide a step-by-step guide in its application. The 

method described is a modification of the standard 

NURE method (U.S. Department of Energy, 

1980). For purposes of comparison, calculations by 

both methods are made in our first area of study. 

The new method is intended to be used by USGS 

scientists in their geologic studies and in assessment of potential uranium resource regions. 

The second purpose of this report is to provide 

the public an insight into plans to continue a program to update our Nation's uranium resource 

base. The USGS has assumed the role of providing 

3 

basic data on estimates of uranium endowment in 

new areas as well as reevaluations of areas assessed during the NURE program prior to 1983. 

These data will be applied by EIA to the economic 

model to develop estimates of the current economic portions for the Uranium Industry Annual 

Report. 

ACKNOWLEDGMENTS 

The DOE file material on uranium resource 

assessment methodology prepared by the DOE 

staff in the 1970s and 1980s was particularly 

helpful in preparing this report. We appreciate the 

participation of J.K. Otton and C.T. Pierson in the 

elicitation of data for the example given in the first 

study area described below. Consultation with 

Luther Smith, EIA, on many aspects of the development of the DSF method and other matters 

related to this report are gratefully acknowledged. 

Helpful discussion with D.P. Harris, University of 

Arizona, led to the development of figure 2. 

METHODOLOGY 

The methods for estimating undiscovered 

uranium resources have received a great amount 
of attention since 1975, mainly as part of the 

NURE Program (Harris, 1976, 1977, 1984; U.S. 

Department of Energy, 1980; Harris and Agterberg, 1981; Harris and Carrigan, 1981). To a varying degree, these methods are all somewhat 

subjective. Recently, an effort by McCammon and 

others (1986) has attempted to reduce this subjectivity by integrating large data sets with genetic 

models in a relatively well-explored basin in New 

Mexico. The most widely applied method, referred 

to in the MOU as "the Standard Methodology," 

is that of the NURE Program reported by the 

DOE in 1980 (U.S. Department of Energy, 1980). 

In our current resource assessment work as 

prescribed in the MOU (appendix A, "Conduct of 

follow-on potential resource appraisal work"), we 

developed a modification of the NURE method to 

estimate the undiscovered uranium endowment. 

To explain this modification, the standard NURE 

method is first described below. 

STANDARD NURE METHOD 

The standard NURE method is described in the 

October 1980 assessment report on uranium in the 

United States (U.S. Department of Energy, 1980, 

p. 23-29), and an example of its application was 

given by Hetland and Grundy (1977). 

The standard NURE endowment equation is as 

follows: 

1U=A·F·T·G·P (1) 

where: 

U =unconditional uranium endowment in tons 

U30 8 above a cutoff grade of 0.01 percent 

UaOa, 

A =projected surface area of favorable ground 

in square miles2, 

F =fraction of A that is underlain by endowment, 

T =tons of endowed rock per square mile within 

A·F2, 

G =average grade of endowment, in decimal form, 

and 

P =probability of occurrence, a factor that expresses the likelihood that one or more 

deposits actually exist within the favorable 

area. 1

For simplification, we have combined equations U=Ue·P0 and Ue=A·F·T·G, 

where Ue=conditional endowment, and use Prather than P. 2

A may be estimated also in volume (cubic miles) or length (mlles); then T must 

be expressed as either tons per cubic mile or tons per linear mile. 

4 

The formula is applied using values of A, F, T, 

G, and P obtained from the principal scientist by 

a team of elicitors. 

Favorable area, A, is obtained by measuring the 

area determined by scientific study to be favorable 

as drawn on a map, most commonly on a quadrangle map at a scale of 1:250,000. The area need 

not comprise contiguous segments, but each segment should have the potential of containing at 

least one deposit of the type represented in the 

selected control area and should be amenable to 

the same grade-tonnage model. Where the favorable area extends onto one or more adjacent maps, 

the total favorable area on all of the maps is 

measured and the proportion for each map is 

recorded. The favorable area excludes areas of mining and reserves. Because A is treated as a constant, it is assigned a single value. 

Factor F is a variable and the lower (5 percent 

probability), most likely (mode), and upper (95 percent probability) values are estimated. The fraction of the favorable area, A, underlain by uranium 

endowment, F, can be estimated in several ways. 

First, F can be computed directly by comparing 

the favorable area with a selected control area and 

estimating the area underlain by endowment in 

square miles and dividing this value then by A to 

give F as a decimal fraction. Second, the number 

of deposits of a selected size that are likely to exist within A are estimated, based on the frequency of occurrence of deposits in the control area, and 

F is obtained by dividing A into the product of the 

number of deposits multiplied by the area of the 

average deposit. Third, if geologic information is 

insufficient for either of the above two ways, F is 

estimated directly from the selected control area. 

In any case, the geologic reasoning in support of 

the estimate is recorded. 

Factor Tis obtained by multiplying the average 

thickness of the endowed portion of the host rock 

by the mean (average) density of the rock in tons 

of rock per square mile per foot of thickness. Tis 

expressed as tons of rock per square mile as 

follows: 

T=c·d·t (2) 

where: 

d =density of endowed rock, 

t =average thickness, in feet, of the layer which 

constitutes the endowed rock, and 

c =conversion factor equal to 62.4 · 5,2802/2,000 

= 869 806.

1 short tons . 

' mi2 X 1 ft 
The average thickness is estimated by comparing 

the favorable area with the analogous control area. 

Lower, most likely, and upper values are estimated, and the geologic reasoning for each is 

recorded. 

Factor G is the estimated grade (percent U30 8), 

based either on known deposits near the favorable 

area or on the average grade for an analogous control area, adjusted where warranted by geologic 

conditions. The geologic reasoning for the choice 

of grade is recorded. To make G consistent with 

units in the equation, the percentage for G is converted into a decimal by dividing by 100. 

The uncertainty of the actual existence of one 

or more uranium deposits in the favorable area is 

elicited from the principal scientist. This probability factor, P, is expressed as a number between 

0.0-1.0. P is difficult to estimate, but to assume 

always that the favorable area is identical to the 

control area will result in overstating the 

endowment. 

A computer program that treats the uncertainties associated with the factors F, T, and G is used 

to calculate U. The result is then discussed with 

the principal scientist to see if the value is reasonable. If the value for U is judged to be either too 

high or too low, the estimates for the factors in 

the equation are reevaluated and adjusted for 

justifiable geologic reasons, and a new value for 

U is calculated. This process is repeated until the 

principal scientist and the elicitors are in agreement. Factor F has the largest possible variation 

of the variables (O.X -O.OOOOX); it is the most difficult factor to estimate and is most commonly the 

factor adjusted most in elicitations. The difficulty in estimating F led to the USGS modification 

given below. 

In the past, DOE has applied economic factors 

to the unconditional endowment estimate to obtain the potential (mineable) resources in three 

forward-cost categories to cover a wide range of 

economic interests (Blanchfield, 1980; U.S. Department of Energy, 1980, p. 23-24). This procedure 

required a large technical staff, as well as an annually updated data base, and, with the closing of 

the Grand Junction Office in 1983 and continued 

low government budgeting, such an analysis is no 

longer feasible on a large scale. The responsibility 

of estimating potential resources is that of E lA, 

and now reserve data are collected annually by 

solicitation from industry. Because industry does 

not have uniform reserve calculating procedures, 

5 

the reserves will be reported in more general terms. 

To aid in economic analysis, the USGS-generated 

data will include the physical and chemical characteristics of the ore (Blanchfield, 1980). 

DEPOSIT -SIZE-FREQUENCY METHOD, 

A MODIFICATION OF THE 

STANDARD NURE METHOD 

The need for a modified and more flexible appr.oach to estimating the undiscovered uranium endowment within an area derives from the difficulty 

experienced by principal investigators during the 

NURE Program in estimating the factor F, the 

fraction of favorable area underlain by endowment. The difficulty in estimating F arose from a 

number of considerations that included the kind 

and quality of the available data, the level of exploration activity in the favorable area, the state 

of knowledge about the mode of occurrence of the 

type of deposit being considered, and the size of 

the area being assessed. These difficulties were 

thoroughly discussed by Harris (1984, p. 364-367). 

In most cases, the factor F was estimated by considering how many more of the best-known, usually the largest, deposits of the type being 

considered were likely to exist in the favorable 

area. Partly because of this but mostly because 

geologists tend to think of deposits as purely 

geologic entities rather than as ore bodies with 

specific dimensions, a modified method is developed herein whereby the number of deposits of a 

given size is explicitly included in the estimation 

equation. 

To emphasize the use of geologic knowledge in 

the estimating process and to provide greater flexibility in the endowment equation, the standard 

NURE endowment equation is modified first by 

replacing factors F and T by a single factor; this 

factor includes estimates of the number of deposits 

of different deposit-size classes within the favorable area, A, or, equivalently, the spatial density 

of deposits; hence, the name "deposit-sizefrequency" method. Second, Pis replaced with an 

optional factor L. The general equation then 

becomes: 

I u =A .E. k (y) nic Ti l G . L 

l-1 c 

(3) 
where: 

U =unconditional uranium endowment in tons 

of U30 8 above a cutoff of 0.01 percent U30 8, 

A=favorable area in square miles, 

k=number of deposit-size classes, 

ni/Ac=spatial density (number of deposits/unit 

area) of deposits of size Ti(tons of endowed 

rock) in the ith deposit-size class within a control area A c' 

Ac=control area from which estimates of ni/Ac 

are taken, 

G=average grade of endowment, in decimal fraction form, and 

L=optional scaling factor that expresses the 

relation between the endowment in the favorable area and that in either the control area or 

some designated subarea for which estimates 

of the number of deposits in different size 

classes have been made. 

The random variables are U, (n1/Ac)+(n2/Ac)+ 

. . . (nk/Ac), G, and L. The key assumption is 

that these variables are independent. 

The term ni/Ac in the expression that replaces 

F and Tin equation 1 is a measure of the relative 

number of natural discrete physical objects, 

whereas F, which is the fraction of A containing 

the endowment, in equation 1 is an abstraction. 

The drawings in Figure 2 illustrate this difference. 

The value F in the standard NURE method is 

dependent upon the boundary of A, arbitrary, and 

difficult to ascribe, whereas the deposit-density 

factor ni/Ac is independent of the boundary of Ac. 

The introduction of this spatial density distribution disaggregates the input and permits one to 

relate size and grade of known deposits to identifiable and measurable geologic features, such as 

character of sedimentary or structural forms in a 

control area. This gives the scientist a means of 

evaluating the potential numbers and sizes of 

deposits at specific grade cutoffs in the study area. 

This form of representation allows adjustments 

either upward or downward for estimated values 

for the favorable area relative to the control area 

or proto-control area. As in the case of the standard NURE method, the size of a deposit expressed 

in tons of endowed rock is assumed to be statistically independent of the average grade of the endowment. The available data tend to support this 

assumption (Harris, 1984, p. 289). 

To make the deposit-size-frequency method as 

6 

flexible as possible, the principal scientist can 

estimate the number of deposits using one of three 

options, depending on the level of knowledge, extent of exploration, and size of area being assessed. 

Option A: In cases where the favorable area has 

been examined in sufficient detail (L=l.O) and 

where estimating directly the number and size of 

deposits that may occur is possible, equation 3 

becomes: 

B 

A 

A 

T= A · F · Tc 

Where: T = Tons of endowed rock 

F = Fraction of A with unspecified 

area underlain by endowed rock 

Tc =Tons/unit area of endowed ground 

(equal to T of equation 1 ) 

Log T 

Where: k = Number of deposit-size 

classes 

T1 =Tons of endowed rock 

in size-class 1 

(4) 

FIGURE 2.-Comparison of F of the standard NURE method 

with the n./ A of the deposit-size-frequency method. A, 

standard NURE method (equation 1); B, deposit-sizefrequency method (equation 3). 
Option B: In cases where the favorable area has 

been examined cursorily but sufficiently so that 

spatial densities of deposits of different sizes can 

be estimated with reference to a control area 

(L=l.O), equation 3 becomes: 

(5) 

Option C: In cases where the favorable area can 

be delineated but has been examined in detail only 

for some portion, that is, a proto-control area, Ac, 

so the number and size of deposits within that portion can be estimated, equation 3 becomes: 

(6) 

The factor L is assumed to be independent of the 

other factors and is estimated by the principal 

scientist as the relation between the undiscovered 

endowment in the portion of the favorable area for 

which estimates of the number and size of deposits 

are made and the undiscovered endowment in the 

favorable area. L can take on any positive value. 

Small values of L are expected, generally much 

less than 1.0, simply because of a lack of knowledge about the favorable area. Therefore, option 

C will result invariably in an estimate of undiscovered endowment with the widest range of possible values. 

At the beginning of the elicitation, the principal 

scientist must decide which option (A, B, or C) is 

to be used. Such a decision takes into consideration the level of knowledge about the geology, the 

extent of exploration, and the size of the area being assessed. Depending upon which of the three 

options is chosen, the appropriate values for the 

parameters in equations 3, 4, 5, or 6 are elicited and 

recorded in the summary form shown in figure 3. 

The relation of depth versus endowment is an 

important factor for economic. evaluation by the 

EIA. Each estimate of endowment is partitioned 

in percentage in the required depth ranges of 

0-100, 101-200, 201-300, 301-400, 401-500, 

501-1,000, 1,001-1,500, 1,501-2,000, 2,001-3,000, 

3,001-4,000, and 4,001-5000 ft. The maximum 

depth to be considered is 5,000 ft. 

7 

THE ASSESSMENT PROCEDURE 

The assessment procedure for a chosen area of 

study consists of a sequence of seven steps: (1) 

determination of geologic favorability, (2) selection 

of control area, (3) development (or selection of an 

established set) of grade-tonnage data, (4) development of deposit-size-frequency data, (5) selection 

of option for calculation of endowment and estimation of necessary factors through elicitation or, if 

the principal scientist is fully qualified, singlehandedly (review process may substitute for 

elicitation), (6) calculation of endowment, and (7) 

expert peer review of steps 1-6. Prior to beginning 

step 1, the principal scientist should study this 

manual of instructions to prepare for the elicitation and expert review. 

GEOLOGIC FAVORABILITY 

Determination of the geologic favorability for 

uranium deposits of a given area is based on 

analogy with the geology of an area known to contain a specific type of uranium deposit. Guides or 

criteria to recognize areas having similar geologic, 

geochemical, and geophysical characteristics have 

been established for the world-class and other important deposits. These criteria are reported as 

conclusions of hundreds of reports on areas 

studied during the past 30 years, and several summaries of recognition criteria are available for use 

in resource assessments (Mickle and Mathews, 

1978; Mathews and others, 1979). 

The study of an area for estimation of uranium 

endowment proceeds from a general determination 

of favorability to the specific outlining of the 

favorable area. Table 1 is an aid in studying and 

summarizing the geologic favorability of an area. 

From this, the actual boundaries of the favorable 

area are drawn on the basis of controlling geologic 

features, such as favorable rock outcrop; distribution of a distinctly favorable sedimentary facies; 

area of faulting, shearing, and fault intersections; 

and areal distribution of a favorable unconformity. For purposes of National resource records, the 

area is drawn on an appropriate National Topographic Map Service (NTMS) 2 o quadrangle map 

(scale 1 :250,000). 

For application of the deposit-size-frequency 

method, particular attention is paid to the specific geologic features that are known from an 
Favorable area: 

Quadrangles (indicate %endowment in each): 

Deposit type: 

Control or proto-control area: 

Grade-tonnage model: 

Estimates: 

A: 

d: 

Size class 

k 

2 

3 

4 

Tons of ore 1 , 

or contained U3 0 8 

per deposit 

Lower 

limit2 Upper 

limit3 

t: 

Date: 

Principal scientist: 

Elicitors: 

Ac L: 

Depth: 

Size-class density 

(number of deposits) 

Lower Most Upper 

limit2 likely limit3 

1 

Average grade(% U308 ) - lower: most likely: upper: 

Cutoff grade (% U30s): . Indicate if ore not used. 2 

Lower limit taken as the 5 percent confidence level. 

:Upper limit taken as the 95 percent confidence level. 

k may be less th_an or greater than 5. The number and size limits of classes should reflect the size distribution of 

known depos1ts. Est1mate the midpoint of the largest size class. 

FIGURE 3.-Elicitation summary form for the deposit-size-frequency method. 

analogous control area to be related to the spatial 

density of occurrence of uranium ore deposits. 

Identification of such features will aid in estimating numbers of deposits in the different size 

classes for the estimating equation (equations 

3-6). Also, mapping the distribution of those 

features containing uranium deposits of a particular size will be necessary; an example is the 

relation of elongate tabular uranium deposits to 

the length and width of fluvial channels. 

8 

CONTROL AREA 

A control area is a specific geographic area for 

which geologic characteristics (recognition 

criteria), uranium reserves, potential resources, 

and production are known. More than 50 wellestablished control areas, as well as less completely established ones, were defined during the 

NURE Program (Hetland and Grundy, 1977). A 

completely described control area of the NURE 
TABLE 1.-A form listing topics to annotate for comparison 

with available criteria to recognize favorability of an area for 

uranium (after U.S. Department of Energy, 1980, fig. 17) 

Topic 

Tectonic setting 

Regional geology 

Regional structure 

Local structure 

Host-rock age 

Host-rock lithology(ies) 

Host-rock mineralogy 

Host-rock texture 

Host-rock geometry 

Chemistry 

Alteration 

Uranium minerals 

Nature of mineralization 

Geometry of ore body(ies) 

Source of uranium 

Occurrence of uranium1 

Other 

Description Fit Rank 

1

Location of mines, airborne and surface radiometric anomalies, and stream· 

sediment and water uranium anomalies. 

program consisted of the following: ( 1) a set of 

geologic recognition criteria; (2) a map of the outcrop of the host formation, the downdip extent of 

thoroughly explored land, and locations of mines 

and reserve blocks; (3) size, thickness, and grade 

distribution for mining properties (a mining property commonly is not a single geologic deposit as 

one property might cover a whole deposit, parts 

of several, or only a part of one deposit); (4) distribution curves for the in-place inventory of U30 8 

by grade; (5) range in depth to ore; and (6) a set 

(lower limit, most likely value, and upper limit) of 

values for theA, F, T, and G factors in the standard NURE equation for estimating the undiscovered uranium endowment. 

In the deposit-size-frequency method, values for 

F and T are not required. In their place is a tabulation of the numbers of deposits, expressed as lower 

limit, most likely value, and upper limit for each 

size class within the control area. 

Although established control areas exist for 

many types of uranium deposits, possibly none will 

be applicable to a particular area. This is the case 

for the study area described below where no control 

area exists for the newly identified type of uranium 

deposit in young organic-rich sediments. In this example, a proto-control area was established, based 

on data from the best known area but where production has not taken place. Grade-tonnage data 

were available for one deposit in the area. 

9 

DEVELOPMENT OF GRADE-TONNAGE 

DISTRIBUTIONS FOR CONTROL AREAS 

Knowledge of uranium grade and tonnage 

distributions of deposits in a given control area is 

essential for the proper application of the depositsize-frequency method and of the economic model 

used by EIA to calculate potential Estimated Additional Resources. These grade-tonnage data will 

allow the principal scientist to estimate the 

numbers of deposits of various sizes and grades 

that one might expect to find in a favorable area. 

For the economic model, the distribution must be 

expressed as a set of grade-tonnage curves that 

show the increase in tonnage with the decrease of 

average grade at specified grade cutoffs. 

In areas where no grade-tonnage data are available from the files of the NURE Program and 

where the available data are not suitable (for example, where mining property information does 

not correspond to a single deposit as discussed 

above), new grade-tonnage distributions will need 

to be developed. For new areas, grade-tonnage data 

may be developed in two ways: ( 1) from a single 

well-developed deposit in the control area or (2) 

from available production and reserve data on all 

known deposits in the well-explored part of a control area In either case, the average grade and tons 

of contained U30 8 at selected cutoff grades are 

tabulated, for example: 

Grade cutoff Average grade Thns of U3

0 8 

(% U308) (% U308) 

0.01 0.06 283,000 

.02 .07 267,000 

.03 .09 246,000 

.04 .11 218,000 

.05 .13 200,000 

.06 .14 183,000 

.07 .15 168,000 

.08 .17 156,000 

.09 .18 143,000 

.10 .20 133,000 

.11 .22 124,000 

.12 .23 112,000 

.13 .24 106,000 

.14 .26 97,000 

From the above data derived from Hetland and 

Grundy (1977), the grade-tonnage curves may be 

constructed as shown in figure 4. The economic 

model requires the slope of the average-grade line 

and the first three moments to calculate potential 

resources. 
LJ.J 

0 

<( 

a: 

e, 

70 

t±: 60 0 

f-

::::> 

u 

LJ.J 

> 0 

co 

<( 

~ 50 

~ z 

LJ.J 

> 

z 

u.. 

~ 40 z 

LJ.J 

u 

a: 

LJ.J 

a.. 

30 

20 

10 

CUTOFF GRADE. PERCENT U30 8 

Percent of total inventory above 

0.09% U308 cutoff of base 

potential (48%) 

Average grade of 

base potential 

(0.18% U30 8 ) 

0.40 

00 

0 

::l "' 

fz 

LJ.J 

u 

a: 

LJ.J 

a.. 

LJ.J 

0 

0.30 ~ e, 

0.20 

0.10 

u.. 

u.. 

0 

f-

::::> 

u 

LJ.J 

> 0 

co 

<( 

>- a: 

~ z 

LJ.J 

> z 

u.. 

0 

LJ.J 

0 

<( 

a: 

e, 

LJ.J 

e, 

~ LJ.J 

~ 

FIGURE 4.-Grade-tonnage curves for the Ambrosia Lake control area, New Mex. (from Hetlund and Grundy, 1977). 

Inventory is the total tons of pre-mining, in-place U30 8 at various cutoff and average grades. 

10 
DEVELOPMENT OF 

DEPOSIT -SIZE FREQUENCY DATA 

The initial step in the development of a sizefrequency distribution for a particular class of 

deposit is to compile the number of known 

deposits of various sizes (tons of contained U30 8 

above a given grade cutoff) within a control or 

proto-control area. The sizes are ranked from 

smallest to largest, and the number of deposits in 

classes are chosen in either geometric or lognormal (not arithmetic) intervals to cover the size 

range of the known deposits. The number of 

classes should be small, generally 4-10. 

ELICIT AT ION 

Elicitation of the undiscovered uranium endowment involves formalized discussion between the 

principal scientist and the team of experts to 

review the investigation and to derive the factors 

needed to calculate the uranium endowment of a 

favorable area. The elicitation is divided into three 

parts. The first part establishes the geologic basis 

for defining a favorable area, identifying the expected deposit(s) type, and selecting a control area 

and its corresponding grade-tonnage model. This 

information is recorded on the form for geologic 

factors shown above in table 1, and these factors 

are compared directly with similar information for 

the control area to check the fit. The second part 

involves elicitation and the recording of both the 

values for the factors in the endowment equation 

and the geologic reasoning for their estimation. 

The third part consists of summary review of factor estimates and their geologic rationale. If 

necessary, the factors are modified before the 

calculation of the endowment. The calculation of 

the endowment is made using a computer program 

modified after the program described by Ford and 

McLaren (1980). 

The endowment estimates are studied and discussed, and, if both groups agree that the values 

are reasonable, they are accepted. If not, the process is repeated until an agreement on a reasonable 

endowment is reached. 

Elicitation is the key element in both methods. 

It is a convenient, relatively fast, thorough, complete, and continuous process of unbroken steps 

leading from the known to the undiscovered endowment. Furthermore, it leaves an audit trail 

11 

that consists of favorable-area definition, selection 

of a control area and a grade-tonnage model, 

equation-factor estimates, and endowment calculation that is defensible. If necessary, any part of 

the process can be modified without affecting the 

other parts. Such feedback is the main strength 

of elicitation. The creditability of the estimate can 

be judged on the basis of the audit trail. 

CALCULATION OF THE ESTIMATE 

The estimate of the endowment for the depositsize-frequency method is calculated using equation 

3, 4, 5, or 6, depending upon the option chosen to 

fit the situation applicable to the study area. The 

computer program described by Ford and 

McLaren (1980) was modified to accept input 

values for the number of deposits of each size class 

and to sum the tonnage over the range of size 

classes. In this summation, a perfect correlation 

between the number of deposits and deposit-size 

class is assumed. 

In this report, computer generated resource 

numbers· are not rounded to significant figures in 

order to permit the reader to utilize the numbers 

and round as desired. 

REVIEW PROCESS 

Review of the endowment estimate will consist 

of two parts: (1) scientific review by a panel of experts, one of whom will be a non-USGS person and 

(2) supervisory review by appropriate Branch 

Chiefs and by a representative of EIA. These 

reviews will precede publication of the estimate. 

COMPARISON OF THE TWO METHODS 

To compare the deposit-size-frequency method 

with the standard NURE method, we estimated 

the undiscovered endowment by both methods. 

The Colville-Okanogan region of Washington and 

Idaho was chosen for the comparison because 

study of the region was nearly complete by J .K. 

Otton, USGS, Project Chief of the Surficial 

Uranium Deposits Project. This region was a particularly good choice because Otton was involved 

in the 1980 NURE assessment. 
THE COLVILLE-OKANOGAN STUDY AREA 

The Colville-Okanogan region, named after the 

two forests with those names, is located in the 

Sandpoint and Spokane NTMS 2 o quadrangles 

(fig. 5). The favorable area consists of small to 

large patches of outcrops of Tertiary granitic rocks 

and associated alluvial sediments, and thus, it is 

not a contiguous area of study. Nevertheless, the 

region may be treated as a single geologic entity 

with respect to its undiscovered uranium endowment. The region contains a few known young 

organic-rich uranium deposits, a new class of 

deposits thought to have a high potential for 

uranium production at a comparatively low cost 

(Otton, 1984a, 1984b). Because these deposits were 

recognized after 1983, no recognition criteria or 

control areas were available for the assessment. 

Therefore, the necessary descriptions are given 

below. 

RECOGNITION CRITERIA FOR 

YOUNG ORGANIC-RICH URANIUM DEPOSITS 

By J.K. Otton 

This new class of uranium deposits is described 

here as an addendum to GJBX-32 (79) prepared 470 L_ _______ __L_ _______ ____il 

by Mathews and others (1979) for the NURE program. The format of this description conforms to 

that used by them. 

Young organic-rich uranium deposit: class 260 

(Otton, 1984a,b). 

Tectonic setting: Mobile belt, Precambrian to 

middle Tertiary. 

Regional geology: Faulted, sheared Precambrian 

to early Tertiary granitic rocks {granodiorite to 

granite, especially two-mica granite); silicic 

volcanic terranes in high plateau areas. 

Climate: Cool to temperate, moderate rainfall; 

usually supports heavy vegetation. 

Geomorphology: Glaciated terrane, generally 

moderate to high relief, first-through third-order 

streams, pothole lakes, fresh-water to alkaline 

marshes in closed basins. 

Regional structure: Faults, fractures, and shears; 

a regional Tertiary unconformity may be 

significant. 

Host rock: 

Age: Late Pleistocene to Holocene. 

Geometry: Long winding channel, oval basinal 

fillings, hill slope. 

50 KILOMETERS 

~-L--r-'1 ''--..L...,' lr-----l-----rl1 

30 MILES 

FIGURE 5.-The Colville-Okanogan favorable area (stippled) 

and Lake Gillette proto-control area (cross-hatched) in the 

Sandpoint (upper) and Spokane (lower) NTMS 2 ° quadrangles, Washington, Idaho, and Montana. Modified by 

J. K. Otton after Castor and others (1982, fig. 2) and 

Fleshman (1982, pl. 6). 

Lithology: Arkosic sand, sandy silt, silt, clay, and 

(or) peat; 2-100 percent organic matter. 

Mineralogy: Organic matter, quartz, feldspar, 

mica, clay. 

Texture: Medium-grained to clay-sized material, 

poorly to well-sorted. 

Depositional environment: Fluvial, lacustrine. 

Associated rocks: Granite or silicic volcanic basement in the drainage basin of the host 

sediment. 

Alteration: Decay and humification of organic 

matter. 

12 
Uranium and uranium-bearing minerals: 

Primary: Uranium adsorbed by organic matter; 

uranium locally reduced during diagenetic processes. No crystalline mineral species recognized 

to date. 

Secondary: Rare. Occur only where an older host 

is being dissected during the rejuvenation of a 

drainage. 

Note: Because of gross secular disequilibrium, 

these organic-rich uranium deposits are 

generally very low in radioactivity". 

Associated elements: Minor Cu, Mo, Ph, Zn. 

Example: Flodelle Creek deposit, Stevens County, Wash. 

References: Mathews and others, 1979; Otton, 

1984a,b; Otton and Culbert, 1984; Cameron, 1985; 

Johnson and others, 1985; Macke and others, 

1985; Otton and others, 1985; Otton and Zielinski, 

1985, 1986; Zielinski, Bush, and Rosholt, in press; 

Zielinski, Otton, Wanty, and Pierson, in press. 

DESCRIPTION OF THE LAKE GILLEnE PROTO-CONTROL AREA 

FOR YOUNG ORGANIC-RICH URANIUM DEPOSITS 

By J.K. Otton 

The Lake Gillette proto-control area corresponds 

to the boundaries of the 7.5-minute quadrangle of 

the same name (fig. 5). It was chosen because the 

best known deposit, Flodelle Creek (Joy Mining 

Company, 1983), occurs in the quadrangle. Two 

sets of data were generated: one for the standard 

NURE method (table 2) and the second for the 

deposit-size-frequency method (table 3). 

TABLE2.-Values of A, F, t, and G for the standard NURE 

method. 

Factor Estimated Values 

A 49.68 mi2 

F 1 lower limit=0.1% or 1 X w-3; most likely value=0.2%, 

or 2X10-3; upper limit=0.8% or 8X10-3 

t2 lower limit=1 ft, most likely=3 ft, upper limit=13 ft 

G lower limit=0.02, most likely=0.03, upper limit=0.08, 

all in percent U30 8 

1

Based on determinations of: {1) length of permanent streams plus long axis of 

kettle holes=24.15 mi; (2) width of outcrop of potential host sediments: 

range=100-400 ft, average=200 ft; (3) area of potentially uranium-bearing ground: 

25.5X 106 ft2

, or 0.914 mi2; and (4) percentage of potential area mineralized: 10% 

(range 5-40%). 2

T was computed using equation 2. 

ESTIMATE BY THE STANDARD NURE METHOD 

The procedure began with the elicitation; the account of this exercise follows: 

A summary of basic information to identify the 

area being investigated and the participants is as 

follows: 

Favorable area: Colville-Okanogan. 

Quadrangles: Sandpoint, WA-MT-ID (90%); 

Spokane, W A-ID (10%). 

Deposit type: Young organic-rich uranium 

deposit. 

Grade-tonnage modeL· Flodelle Creek. 

Principal scientist: James K. Otton. 

Elicitors: Warren I. Finch (leader), Richard B. 

McCammon, Charles T. Pierson. 

TABLE 3.-Values of Ac and size distribution of deposits for the deposit-size-frequency method 

Proto-control area, Ac =49.68 mi2 

Size-class interval Number 

Size (Tons mineralized rock) of deposits 

class Lower Upper Lower1 Most Upper1 

(k) limit Midpoint2 limit (0.05) likely (0.95) 

1 2.5X103 7.9X103 2.5X104 2 4 310 

2 2.5X104 7.9X104 2.5X105 4 8 18 

3 2.5X105 7.9X105 2.5X106 3 6 9 

4 2.5X106 7.9X106 2.5X107 0 0 1 

1

0dds are 9 to 1 that the true numbers lie between lower and upper estimates. 2

Midpoints of size-class intervals for size classes 1-4 are defined as the geometric mean of the upper and lower limits. 3

The number of deposits in size class k=1 does not follow the expected distribution of most epigenetic uranium deposits for 

which the largest number of deposits are estimated for the smallest size class. The departure is due to the natural occurrence of 

the organic-rich uranium deposits. The uranium deposits are constrained in size by the volume of the alluvial valley fills. This 

and the fact that the valley-fill material is commonly extensive and largely continuous preclude many small uranium deposits. 

Furthermore, some deposits are related to spring seeps at edges of alluvial fill, and these deposits are generally of considerable 

size; in this area they fall mostly in size classes K=2 and K=3. 

13 
Date: February 8, 1985. 

Elicitation of recognition criteria for the ColvilleOkanogan favorable area (compared to recognition 

criteria above using form of table 1): 

Topic 

Tectonic setting: 

Regional geology: 

Local structure: 

Host-rock age: 

Host-rock geometry: 

Host-rock lithology: 

Host-rock mineralogy: 

Host-rock texture: 

Chemistry: 

Alteration: 

Uranium minerals: 

Nature of mineralization: 

Geometry of ore body: 

Source of uranium: 

Reductantsladsorbants: 

Occurrence of uranium: 

Description Fit Rank 

Mobile belt. X 

Granite intrusions, X 

recent uplift (since 

Cretaceous), 

Pleistocene glaciation. 

Faults, fractures, X 

shears. 

Late Pleistocene and X 

Holocene. 

Long sinuous channel X 

(valley-fill), oval 

tabular (lake, basin 

fill), irregular tabular 

(hillslope seeps). 

Sand, sandy silt, silt, X 

clay, peat, organicrich (2-95% loss on 

ignition). 

Organic matter, X 

quartz, feldspar, 

clay, mica. 

Medium to fine X 

grained, porosity 

locally very high, sp 

gr=0.2-1.8. 

U; trace of Cu, Mo, X 

Zn; no C03, possible 

bacteriogenic sulfide. 

Diagenetic humifica- X 

tion of organic 

matter, local 

bacteriogenic sulfide 

production. 

No primary minerals X 

recognized. 

Adsorption on organic X 

matter and clay, 

reduction by sulfides 

and organic matter. 

Coextensive with X 

host. 

6 

5 

3 

4 

Granite, granodiorite. X 1 

Organic, bacteriogenic X 2 

sulfide. 

X 

Within the Colville-Okanogan favorable area (exclusive of the proto-control area), estimates of the 

most likely value and the upper and lower bounds 

of the value were obtained for each of the factors 

in equations 1 and 2. A summary of the input 

values is: 

14 

Factor 

A 

F 

d 

t 

G 

p 

Lower1 

(0.05) 

0.001 

.7 

1 

.02 

Most 

likely 

2020 

0.002 

1.2 

3 

.03 

1.0 

Upper1 

(0.95) 

0.008 

1.5 

8 

.08 

1

0dds are 9 to 1 that the values lie between the lower and upper estimates. 

The value of T, tons of rock per square mile with 

A · F, is calculated using equation 2. 

Rationale for estimation of endowment-equation 

factors 

The favorable area is geologically very similar to 

the Lake Gillette proto-control area (see above). 

Furthermore, reconnaissance of the two 2 o quadrangles has revealed anomalous uranium concentrations in young organic-rich sediments 

throughout most of the favorable area: 

A Measured directly from geologic maps, includes 

all granite outcrop areas (fig. 5). 

F Based on two values: (1) percentage of A underlain by wetland (environment generally most favorable for uranium deposits), and (2) estimate 

of the part of the wetland that may contain 

uranium (>100 ppm U30 8). The wetland area is 

measurable from topographic sheets (length of 

permanent stream and long axis of lakes times 

the average width). Fraction of uraniferous area 

is subjectively estimated at 10 percent. 

G Based on Flodelle Creek deposit at cutoff of 

100 ppm U30 8• 

P Considered to be 1.0 because of adjacent control 

area and of established presence of similar 

deposits. 

Using the computer program described by Ford 

and McLaren (1980), the endowment was calculated using equation 1. The mean value of the unconditional uranium endowment within the favorable area is 8,018 tons of contained U30 8• The 

probability distribution for the endowment is: 

1,977 

2,142 

2,307 

2,507 

2,805 

3,121 

3,514 

3,960 

4,468 

5,058 

Percentiles for endowment 

Probability 

unconditional 

(in percent) 

0.05 

.10 

.15 

.20 

.25 

.30 

.35 

.40 

.45 

.50 

5,745 

6,547 

7,493 

8,632 

10,049 

11,855 

14,301 

17,955 

24,721 

Probability 

unconditional 

(in percent) 

0.55 

.60 

.65 

.70 

.75 

.80 

.85 

.90 

.95 
Thus, the odds are 9 to 1 that the true endowment in the favorable area is between 1,977 and 

24,721 tons of contained U30 8• 

ESTIMATE BY THE 

DEPOSIT -SIZE-FREQUENCY METHOD 

The summary of basic information to identify 

the area being investigated is the same as given 

above. C. T. Pierson did not take part in the elicitation, which took place later. 

Principal scientist: James K. Otton. 

Elicitors: Richard B. McCammon (leader), Warren I. Finch. 

Date: July 18, 1985. 

The elicitation of recognition criteria is identical 

to those given above for the standard NURE. 

Estimates made of the most likely number of 

deposits and lower and upper bounds of number 

of deposits within each of four size classes are summarized in table 4. The values for A and G are the 

same as for the standard NURE method. 

The endowment for the Lake Gillette protocontrol area is calculated using equation 6. The 

program to combine the input values and to 

generate the distribution of the unconditional endowment, U, is identical to that of Ford and 

McLaren (1980), except that the estimates of the 

numbers of deposits in the different size classes 

are assumed to be perfectly correlated. Based on 

the estimated number of deposits in each of the 

four deposit-size classes, the unconditional mean 

value of the uranium endowment within the Lake 

Gillette proto-control area is calculated as 3,222 

tons of contained U 30 8• The probability distribution for the uranium endowment of the Lake 

Gillette proto-control area is: 

560 

795 

1,009 

1,215 

1,421 

1,630 

1,846 

2,072 

2,306 

2,562 

Percentiles for endowment 

Probability 

unconditional 

(in percent) 

0.05 

.10 

.15 

.20 

.25 

.30 

.35 

.40 

.45 

.50 

2,838 

3,139 

3,475 

3,857 

4,301 

4,843 

5,532 

6,494 

8,144 

Probability 

unconditional 

(in percent) 

0.55 

.60 

.65 

.70 

.75 

.80 

.85 

.90 

.95 

Thus, the odds are 9 to 1 that the true endowment is between 560 and 8,144 tons of contained 

U30 8 in the proto-control area, Ac. 

To expand this estimate to include the undiscovered uranium endowment in A, the favorable area, 

the similarity of the favorable area to the protocontrol area must be judged to complete the 

estimate, and the principal scientist must estimate 

factor L. 

For this example, the lower limit, the most likely value, and the upper limit of L were estimated 

subjectively as 0.05, 0.1, and 1.0, respectively. 

Thus, the odds are 9:1 that the favorable area is 

at least 1/20th as endowed or at most equally endowed as the control area; most likely, it is 1/10th 

as endowed. 

Based on this determination of the probability 

factor, the unconditional mean value of the 

uranium endowment within the favorable area was 

calculated as 35,299 tons of contained U30. The 

probability distribution for the endowment ~f the 

Coleville-Okanogan favorable area is: 

15 

Percentiles for endowment 

U308 Probability U308 Probability 

unconditional unconditional (Tons) (Tons) (in percent) (in percent) 

6,738 0.05 23,631 0.55 

7,428 .10 27,581 .60 

8,118 .15 32,407 .65 

8,808 .20 38,240 .70 

9,885 .25 45,517 .75 

11,338 .30 54,913 .80 

13,000 .35 67,707 .85 

15,009 .40 86,883 .90 

17,448 .45 122,320 .95 

20,285 .50 

Thus, the odds are 9 to 1 that at least 6, 7 38 tons 

or at most 122,320 tons of contained U 0 exist . h f 3 8 1n t e avorable area. 

The rationales for the remaining parameters are 

as follows: 

1. Number of size-class intervals: a geometric 

scale was used in defining deposit size. The 

lower limit of the smallest size class was 

chosen to include the smallest known 

deposit, and the largest size class interval 

was chosen to allow for deposits larger than 

the largest known deposit. 

2. Numbers of deposits in the different size 

classes: the total favorable area is divided 

into isolated parts and reconnaissance 
mapping and sampling permitted the assignment of varying degrees of favorability. Furthermore, lengths and widths of streams 

varied so that the permissible maximum size 

of deposit was apparent. Comparison of 

these observations with the character of the 

Gillette Creek control area permitted 

deposits larger than the largest known 

deposit in the control area. 

3. Estimated value of L: parts of A are less 

favorable than the proto-control area, and 

other parts are more favorable. The lower 

limit, most likely value, and upper limit 

values of L were estimated on the basis of 

reconnaissance sampling and mapping. 

DISCUSSION 

In the Colville-Okanogan favorable area, the 

estimate of the unconditional mean value of 

uranium endowment obtained using the depositsize-frequency method is 35,299 tons of contained 

U30 8, which is 4.4 times the mean value of 8,018 

tons obtained using the standard NURE method. 

Moreover, the ratio of the range defined here as 

the difference between the 5th and the 95th 

percentiles of the probability distribution of the 

uranium endowment obtained by the deposit-sizefrequency method to the range defined similarly 

for the standard NURE method is 5.1. The 

estimate of uranium endowment obtained by the 

deposit-size-frequency method, therefore, is larger 

and has a greater range of values as compared to 

the standard NURE method. Similar results were 

reported by Harris and Carrigan (1981) and 

McCammon and others (1986) for estimates of 

uranium endowment that were compared to those 

obtained using the standard NURE method in the 

San Juan Basin, New Mex. In general, the more 

disaggregation of the input values in the 

estimating equation and the more the parameters 

in the equation are based on geologic criteria, the 

greater the expected value and the greater the 

uncertainty. As Harris (1984) suggested, the 

greater the degree to which the mental processes 

receive support and aid in the estimation task, the 

less narrow and less conservative the estimate. We 

believe that the DSF method permits the utilization of the Principal Scientist's geological 

knowledge in a less subjective manner than was 

possible in the standard NURE method, and that 

this represents at least a qualitative improvement 

in the appraisal of undiscovered uranium 

resources. 

REPORTING OF ENDOWMENT AND 

INTEGRATION INTO THE 

NATIONAL RESOURCE BASE 

The estimates of the undiscovered uranium endowment made by the USGS will be transmitted 

to the E lA through an interagency memorandum 

report. The report will primarily consist of data 

with very brief descriptions of geology, uranium 

deposits, and rationales for estimating the factors 

in the endowment equation. In addition, for entry 

into the established National NURE data file, the 

necessary identification, estimation of endowment 

factors, and supporting information will be 

reported on the standard NURE form given in 

figure 6. 

To be consistent with the existing NURE 

database and to allow follow-up work to update 

National estimates of potential resources, the endowment factors A, F, T, G, and Pin the standard 

NURE method will be reported in terms of the 

deposit-size-frequency method as follows: 

16 

Standard 

method 

A 

F 

T 

G 

p 

Deposit-sizefrequency method 

A 

1.0 

L 

1 k 

A E nic ·T. 

' i=l 

k nic 

E Ac ·T. 

' i=l 

1 k 

Ac E nic ·T. 

' i=l 

G 

1.0 

Option 

A,B,C 

A,B 

c 

A 

B 

c 

A,B,C 

A,B,C 

For either method, the first four central 

moments of U, the unconditional undiscovered endowment, are handled identically with respect to 

the subsequent application of the economic model. 
1-15 

ID 

CODES 

AS 

~HOWN 

1-15 

ID 

CODES 

AS 

SHONN 

1-15 

ID 

CODES 

AS 

SHOWN 

1-15 

ID 

CODES 

AS 

SHCYtVN 

1-15 

I. IDENTIFICATION 

ft RES. EXP. ORA LOC AGE c REG. AREA 

I I I I I 

I 213 415 617 819 lOIII 

M C FM 

etc. = ~ ~~d 

I 

12113 14 15 

Resource Region _____________________ _ 

Exploration Area ________ _ 

Ore Reserve Area _______ _ 

Locality-----------

Formation _________ _ 

Member _________ _ 

Deposit Type---------

Probability of true value of F, T, or G 

being less than UPPER esti motes 

*For LOWER estimates, 

the default probobili ty is 5o/o. 

For UPPER estimates, 

the default probability is 95%. 

o. Probability of at least one deposit containing at least 10 tons of U308 at a minimum grade of 0.01% U3 08 . 

b. A= area of favorable ground 

in square, linear, or cubic miles. 

c. F = fraction of "A' postulated to be underlain by (or associated with) uranium endowment 

d. T = tons of uranium bearing rock per square, linear, 

or cubic mile within the fractional area "F" 

e. G =overage grade of mineralized rock at a cutoff grade of 0.01% U308. 

ill BACKUP INFORMATION AND ALLOCATION OF POTENTIAL 

CARD DEPTH RANGES= GIVE % OF ENDOWMENT IN EACH RANGE AVERAGE LEAD ~~_!ION DISCMRY 

~ o'- lot- 201- 301- 401'- 501'- 1,001- 1,501- 2,001- 3,001- 4POI- THICKNESS MIN. TIME UNEX- RATE OF ORE TYPE ~ PLORED 100' 200 ?IJO' 400' 500' 1,000' 1,500 2,000 3,000 4,000 5,000 IN FEET YRS LBS/FT. 

4 I I I I I I I I l L _l_l_ 1 I I _l I 1 I _l _l ... ... 16 17118119 20121122 23124125 26127128 29130131 32133134 35136137 3813914<> 41142143 144145146 147148~9 1~51152153 154155 56157 5859160161 ~163~5166 

CARD GEOLOGIC TYPES STATES 

NO. TYPE % TYPE "to TYPE 'Yo TYPE 'Yo ,...-- ST 'Yo ST % ST % ST 'Yo ST 'Yo 

5 1 I 1 _l _[ 1 1 1 I I I I I I I I I I 

!6 17jl8 19j20j21 22j23 24j25 26J27 28l29 30J31 32J33 J34j35 36j37J38 39J40 41j42 4~~ 45j46 47f4s 49J50 51j52 53j54 

CARO NTMS 2° QUADRANGLES 

NO. I-- QUAD CODE 'Yo QUAD CODE "to QUAD CODE 'Yo QUAD CODE % QUAD CODE % QUAD CODE % 

6 N N 1 _1 1 1 1 I N, l N I I l I N I I 

16 17l18[19l2q21[22 23[24125 26I27I28I29I30I31 32133 34[35[36137138139 40[41 ~2143[44145146147 f48149 50151152153[54[55 56[57 58159[60[61[62[63 64[65 

CARD LAND STATUS NO. 

- TYPE 'Yo TYPE 'Yo TYPE 'Yo TYPE % TYPE 'Yo TYPE % TYPE ,. TYPE % TYPE % TYPE % TYPE % TYPE % 

7 l I I I I I I I I I I I 

16 17[18 19l20j21 22[23 24125 26J27 28l29 30j31 32J33 34~5 36137 38[39 [40[41 42j43 ~5 4$7 48j49 50j51 52j53 54j55 56j57 5Bj59 60j61 62J63 64J6~ 

FIGURE 6.-Uranium endowment data form. 

17 
STRATEGY TO UPDATE THE NATIONAL 

URANIUM ENDOWMENT ESTIMATES 

Private exploration for uranium in the United 

States has declined in recent years. The exploration work that has been done, however, has generated important new geologic data that can be 

utilized in the reevaluation of estimations of undiscovered uranium resources made by the DOE 

previously and in the estimations of resources for 

new areas discovered since 1983. 

Data on the projected domestic uranium resource capability under various market assumptions are required by the Energy Information 

Administration for its annual assessment of the 

viability of the domestic uranium mining and milling industry. Within this context, an annual reappraisal is required of the Nation's undiscovered 

(potential) uranium resource base to incorporate, 

to the extent practicable, new geological data 

developed during private exploration activities and 

to assess the results of exploration activities on undiscovered resources. 

The strategy of the USGS is to select for study 

either currently assessed or new unassessed areas 

where recent exploration developments or new geologic and related information have become availabla 

In 1984, four geologic environments were identified 

for USGS uranium resource assessments. They are: 

(1) surficial uranium deposits (SUDS) throughout 

the conterminous United States, (2) uranium in 

collapse-breccia pipes in the Grand Canyon region 

of northwestern Arizona, (3) uranium in Thrtiary 

sedimentary rocks of the Northern Great Plains, 

and (4) uranium in metamorphic rocks of the Piedmont physiographic province in the eastern United 

States. The SUDS areas are in a recently recognized environment of uranium accumulation in 

young sediments and the six general areas selected 

are: (1) Mesozoic!Thrtiary granite terranes of Washington and Idaho, (2) Jurassic and Cretaceous 

Sierra Nevada terranes of California and Nevada, 

(3) the Cretaceous!Thrtiary Idaho batholith region, 

( 4) the Precambrian gneiss-granite terrane of the 

Front Range in Colorado, (5) the Paleozoic granite 

terrane in the New England States, and (6) the 

Precambrian gneiss-granite terrane of the Piedmont Province of the eastern States (fig. 7). 

1b support and prepare for the assessment of the 

four selected geologic environments, the USGS is 

carrying out projects to improve the understanding of the geologic habitats of uranium ores in 

18 

these as well as other environments and to develop 

guides and criteria to delineate areas favorable for 

undiscovered uranium deposits (Fouch and Ridgely, 1985). In these four research projects, 64 NTMS 

2 o quadrangle maps have been selected for 

uranium endowment estimation. They have been 

divided into 28 A priority (most likely to contain 

more than 500 tons U30 8 to be added to the 

resource base) and 36 B priority (less likely to add 

500 tons to the resource base) quadrangles as 

shown in figure 8 and table 4. More than one environment will be studied in some quadrangles. 

The quadrangle total for each of the four geologic 

environments expressed as a fraction of A priority/B priority breaks down as: (1) SUDS, 14/30; (2) 

pipes, 4/0; (3) Northern Great Plains, 1/0; and (4) 

metamorphic-rock hosted, Piedmont, 9/9. 

The schedule for completion of assessment of the 

four environments is uncertain because of restraints 

on budget and personnel and because of the unknown amount of time to complete field and laboratory studies in each quadrangla The first two quadrangles in the SUDS project to be completed are 

the Sandpoint and Spokane in Washington, Montana, and Idaho. The example in this report is based 

on preliminary trials on the elicitation and calculations of the favorable area in these quadrangles. 

INTERNATIONAL NUCLEAR ENERGY 

MINERALS INFORMATION 

Current information on raw materials of the 

nuclear energy fuels, uranium and thorium, is a 

vital input for analyses made by two international 

organizations, the Organization for Economic 

Cooperation and Development, OECD (NEA), and 

the International Atomic Energy Agency, IAEA. 

The USGS has taken part in numerous program 

activities of these organizations beginning with the 

first United Nations International Conference on 

Peaceful Uses of Atomic Energy in 1955. 

In the past 10 years, the USGS has made many 

contributions to the work of the IAEA. In particular, it has contributed information concerning 

thorium geology and resources and uranium program activities related to uranium exploration to 

the U.S. Department of Energy for inclusion in the 

OECD-IAEA (NEA and IAEA, 1984) joint report 

(commonly called the "Red Book") titled 

"Uranium: Resources, Production and Demand;' 

published every two years. The role of the USGS 
1--1 

co 

•o;;::,. 

" \ 

--, .... , 

.............. ,.... __ '" ..... ___ ..,J " 

0 200 400 MILES 

DENVER 

', 

\ ''../ ,. .. " \ 

\\ 

"'\ 

\,., 

~,---

J&1 

FIGURE 7.-Principal surficial uranium deposit terranes in the conterminous United States (J.K. Otton, written commun., 1985) . .P 

A. Washington-Idaho, Mesozoic-Tertiary granites 

B. California-Nevada, Jurassic and Cretaceous Sierra Nevada granites 

C. Idaho, Cretaceous-Tertiary granites 

D. Colorado Front Range, Precambrian gneiss-granites 

E. New England, Paleozoic granites 

F. Piedmont physiographic province, Precambrian gneiss-granites. 
~ 

0 

40° 

0 200 400 MILES 

FIGURE 8.-Map of the conterminous United States showing A-priority (shaded) and B-priority (cross-hatched) NTMS 2° quadrangles for uranium endowment estimation. See table 4 for identification of quadrangles. 
TABLE 4.-Index list to NTMS 2° quadrangles in conterminous 

United States selected to be assessed for their uranium 

resources by the U.S. Geological Survey 

[Keyed to figure 8) 

A PRIORITY 

Map Name, Type of 

no. State deposit 

A1 Alliance, NB Sandstone-type 

A2 Athens, GA, SC Vein 

A3 Augusta, SC Vein 

A4 Challis, ID SUDS 

A5 Charlotte, NC Vein 

A6 Craig, CO SUDS 

A7 Denver, CO SUDS 

A8 Flagstaff, AZ Collapse-breccia pipe 

A9 Fresno, CA SUDS 

A10 Grand Canyon, AZ Collapse-breccia pipe 

All Greeley, CO SUDS 

A12 Greensboro, VA Vein 

A13 Knoxville, TN, NC Vein 

A14 Leadville, CO SUDS 

A15 Lewiston, ME, NH SUDS 

A16 Macon, GA Vein 

A17 Marble Canyon, AZ Collapse-breccia pipe 

A18 Mariposa, CA, NV SUDS 

A19 Montrose, CO SUDS 

A20 Pueblo, CO SUDS 

A21 Reno, NV SUDS 

A22 Richmond, VA Vein 

A23 Roanoke, VA Vein 

A24 Sandpoint, W A, ID SUDS 

A25 Spartanburg, SC, NC Vein 

A26 Spokane, W A, ID SUDS 

A27 Walker Lake, CA, NV SUDS 

A28 Williams, AZ Collapse-breccia pipe 

B PRIORITY 

B1 Ashton, WY SUDS 

B2 Atlanta, GA SUDS 

B3 Bakersfield, CA SUDS 

B4 Bangor, ME SUDS 

B5 Bluefield, WV, VA Vein 

B6 Boston, MA SUDS 

B7 Bozeman, MT SUDS 

B8 Butte, MT SUDS 

B9 Casper, WY SUDS 

B10 Cheyenne, WY SUDS 

Bll Chico, CA SUDS 

B12 Cody, WY SUDS 

B13 Dillon, MT SUDS 

B14 Durango, CO SUDS 

B15 Elk City, ID, MT SUDS 

B16 Florence, SC, NC Vein 

B17 Georgetown, SC Vein 

B18 Greenville, GA, SC Vein 

B19 Hailey, ID SUDS 

B20 Hamilton, ID, MT SUDS 

B21 Millinocket, ME SUDS 

B22 Norfolk, VA, NC Vein 

B23 Okanogan, W A SUDS 

21 

B24 Phenix City, LA, GA SUDS 

B25 Portland, NH, ME SUDS 

B26 Providence, RI, MA, CT SUDS 

B27 Raleigh, NC Vein 

B28 Richfield, UT SUDS 

B29 Ritzville, W A SUDS 

B30 Rocky Mount, NC Vein 

B31 Rome, GA SUDS 

B32 Sacramento, CA SUDS 

B33 Salina, UT SUDS 

B34 Thermopolis, WY SUDS 

B35 Torrington, WY SUDS 

B36 Winston Salem, NC, VA Vein 

has increased since the signing of the 1984 MOU, 

particularly as being formally represented on the 

NEA/IAEA Working Party on Uranium Resources. Furthermore, the closing of DOE's Grand 

Junction Operations Office in 1983 has increased 

our involvement in the field of uranium geology 

to the IAEA. 

As a member state of the IAEA, the United 

States reports its uranium resources, production, 

and other pertinent resource information to the 

Working Party on Uranium Resource, Production 

and Demand on a regular basis, normally every 

two years. The responsibility of reporting of U.S. 

numerical resource data for inclusion in the biennial "Red Book" as a joint report by OECD's NEA 

and the IAEA (NEA and IAEA, 1984) is the prime 

responsibility of the EIA, whereas the reporting 

of supporting geologic data on both uranium and 

thorium is the prime responsibility of the USGS 

(appendix A, section G). 

REFERENCES CITED 

American Society for Testing and Materials, 1983, Standard 

classification system for uranium resources, in 1982, An· 

nual Book for ASTM Standards: Philadelphia, Penn.19103, 

Designation E 901-82, 15 p. 

Blanchfield, D.M., 1980, Methodology for uranium resource 

estimates and reliability, in Uranium Industry Seminar Proceedings, October 22-23, 1980, Grand Junction, Colo.: U.S. 

Department of Energy Report GJ0-108(80), p. 59-76. 

Cameron, C. C., 1985, Uranium in Holocene deposits (abs.): 20th 

Annual Meeting Northeastern Section, The Geological 

Society of America, Abstracts with Programs 1985, v. 17, 

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Canada Department of Energy, Mines, and Resources, Canada, 

1977, Oil and natural gas resources of Canada, 1976: Ottawa, Report EP-77-1, 76 p. 

Castor, S.B., Berry, M.R., and Siegmund, B.L., 1982, National 

uranium resource evaluation, Sandpoint quadrangle, 

Washington, Idaho, and Montana: U.S. Department of 

Energy Report PGJ/F-005(82), 77 p. 
Ellis, J.R., Harris, D.P., and VanWie, N.H., 1975, A subjective 

probability appraisal of uranium resources in the state of 

New Mexico: U.S. Energy Research and Development Administration Report GJ0-110(76), 97 p. 

Energy Information Administration, 1985, Uranium industry 

annual 1984: Energy Information Administration 

DOE/EIA-047(84), 144 p. 

Fleshman, B.R., 1982, National uranium resource evaluation, 

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Ford, C.E., and McLaren, R.A., 1980, Methods for obtaining 

distributions of uranium occurrence from estimates of 

geologic features: U.S. Department of Energy Report 

GJBX-165(80), 121 p. 

Fouch, T.D., and Ridgley, J.L., 1985, Uranium and thorium investigation in the U.S. Geological Survey (abs.) in Krafft, 

Kathleen, ed., USGS Research on Mineral Resources-1985, 

Program and Abstracts, V.E. McKelvey Forum on Mineral 

and Energy Resources: U.S. Geological Survey Circular 949, 

p. 63. 

Harris, D.P., 1976, A survey and critique of quantitative methods 

for the appraisal of mineral resources: U.S. Energy Research 

and Development Administration Report GJBX-12(76), 

624 p. 

__ 1977, Quantitative methods for the appraisal of mineral 

resources: U.S. Energy Research and Development Administration Report GJBX-14(77), 848 p. 

__ 1984, Mineral resources appraisal, mineral endowment, 

resources, and potential supply: Concepts, methods, and 

cases: Oxford, Clarendon Press, 445 p. 

Harris, D.P., and Agterberg, F.P., 1981, The appraisal of mineral 

resources: Economic Geology, 75th Anniversary Volume, 

p. 897-938. 

Harris, D.P., and Carrigan, F.J., 1981, Estimation of uranium 

endowment by subjective geological analysis-a comparison 

of methods and estimates for the San Juan Basin, New Mexico: Economic Geology, v. 76, no. 5, p. 1032-1055. 

Hetland, D.L., and Grundy, W.D., 1977, Potential resources, in 

Uranium Industry Seminar Proceedings, October 26-27, 

1977: U.S. Department of Energy Report GJ0-108(77), 

p. 143-158. 

Johnson, S.Y., Otton, J.K., and Macke, D.L., 1985, Geology of 

the north fork of Flodelle Creek drainage basin and surficial 

uranium deposit, Stevens County, Washington: U.S. 

Geological Survey Open-File Report 85-443, 38 p. 

Joy Mining Company, 1983, Environmental impact statement 

for the proposed Joy Mining Company uranium mine and 

mill: Washington State Department of Social Health Services, 112 p. 

Macke, D.L., Johnson, S.Y., and Otton, J.K., 1985, Sedimentology 

of a surficial uranium deposit on North Flodelle Creek, 

Stevens County, Washington (abs.): Society of Economic 

Paleontologists and Mineralogists Annual Midyear 

Meeting, August 11-14, 1985, Golden, Colo., Abstracts, 

v. II, p. 57-58. 

Mathews, G.H., Jones, C.A., Pilcher, R.C., and D~ndrea, R.F., 

Jr., 1979, Preliminary recognition criteria for uranium occurrences: A field guide: U.S. Department of Energy Report 

GJBX-32(79), 41 p. 

McCammon, R.B., Finch, W.l., Kork, J.O., and Bridges, N.J., 

1986, Estimation of uranium endowment in the Westwater 

Canyon Member, Morrison Formation, San Juan Basin, New 

22 

Mexico, using a data-directed numerical method, in 'lbrnerPeterson, C.E., Fishman, N.S., and Santos, E.S., eds., A basin 

analysis case study-the Morrison Formation, Grants 

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Petroleum Geologists, Studies in Geology No. 22, 

p. 331-355. 

Mickle, D.G., and Mathews, G.W., 1978, Geologic characteristics 

of environments favorable for uranium deposits: U.S. Department of Energy Report GJBX-67(78), 250 p. 

Nuclear Energy Agency and International Atomic Energy 

Agency, 1984, Uranium: Resources, Production and Demand: Paris, France, Organization for Economic Cooperation and Development, 348 p. 

Otton, J.K., 1984a, Surficial uranium deposits in the United 

States of America, in Dennis 1bens, project leader, Surficial 

uranium deposits, Report of the working group on uranium 

geology organized by the International Atomic Energy 

Agency: Vienna, Austria, Report IAEA-TECDOC-322, 

p. 237-242. 

__ 1984b, Surficial uranium deposits in granitic terranes in 

the western United States (abs.): Geological Society of 

America Abstracts with Programs, v. 16, no. 5, p. 327. 

Otton, J.K., and Culbert, R.R., 1984, Uranium in Holocene valleyfill, Carson Range, Nevada and California (abs.): Geological 

Society of America Abstracts with Programs, v. 16, no. 6, 

p. 616. 

Otton, J.K., and Zielinski, R.A., 1985, Movement and concentration of uranium in young, organic-rich sediments, Stevens 

County, Washington: La Societe Francaise de Mineralogie 

et de Cristallographie et Le Centre de Recherches sur la 

Geolgie de !'Uranium, Program and Extended Abstracts, 

p. 49-52. 

__ 1986, Movement and fixation of uranium on organic matter in a late Quaternary uranium deposit, Stevens County, 

Washington (abs.), in Carter, L.M.H. ed., USGS Research 

on Energy Resources-1986, Program and Abstracts, The Second Annual V. E. McKelvey Forum on Mineral and Energy 

Resources: U.S. Geological Survey Circular 97 4, p. 49-50. 

Otton, J.K., Zielinski, R.A., and Been, J.M., 1985, Uranium in 

Holocene valley-fill sediments, and uranium, radon, and 

helium in waters, Lake Tahoe-Carson Range, Nevada and 

California: U.S. Geological Survey Open-File Report 85-389, 

30 p. 

Schanz, J.J., 1975, Resource terminology: an examination of 

concepts and terms and recommendations for improvements: Palo Alto, Calif., Electric Power Research Institute, 

116 p. 

U.S. Department of Interior, 1980, Principles of a resource/ 

reserve classification for minerals: U.S. Geological Survey 

Circular 831, 5 p. 

U.S. Department of Energy, 1980, An assessment report on 

uranium in the United States of America: U.S. Department 

of Energy Report GJ0-111(80), 150 p., 6 microfiche. 

__ 1983, Statistical data of the uranium industry: U.S. 

Department of Energy Report GJ0-100(83), 77 p. 

Zielinski, R.A., Bush, C.A., and Rosholt, J.N., in press, Uranium 

series disequilibrium in a young surficial uranium deposit, 

northeastern Washington: Applied Geochemistry. 

Zielinski, R.A., Otton, J.K., Wanty, R.B, and Pierson, C.T., in 

press, The geochemistry of water near a surficial, organicrich uranium deposit, northeastern Washington State: 

Chemical Geology. 
APPENDIX A 

MEMORANDUM OF UNDERSTANDING 

BETWEEN THE ENERGY INFORMATION ADMINISTRATION 

U.S. DEPARTMENT OF ENERGY 

AND THE U.S. GEOLOGICAL SURVEY 

U.S. DEPARTMENT OF THE INTERIOR 

INTRODUCTION 

This Memorandum of Understanding (MOU) is an agreement between 

the Energy Information Administration (EIA), U.S. Department of 

Energy (DOE), and the U.S. Geological Survey (USGS), U.S. 

Department of the Interior (DOI). The MOU describes the 

implementation of an agreement for assistance from the USGS in 

the assessment of U.S. potential uranium resources in support of 

the EIA's v.'ork under Public Law 97-415 (January 4, 1983) to 

develop and provide information about the viability of the 

domestic uranium mining and milling industry. 

BACKGROUND 

With the close-out in Fiscal Year 1983 of the DOE's Uranium 

Resource Assessment (URA) Program at the Grand Junction Area 

Office (GJAO), including the National Uranium Resource Evaluation 

(NURE) Program, the uranium resource data collected under NURE 

end much of the data collected and compiled over the past 36 

years at the GJAO have been passed to the USGS along with the 

responsibility for conducting follow-on work in potential uranium 

resource analysis. This transfer of data and responsibility is 

consistent with a budget decision made by the Office of Management 

and Budget (OMB) (see action memorandum dated November 22, 1983, 

in the A pp end i x ) . The prior lv1 0 U bet \vee n the D 0 E and the D 0 I 

required the development of a plan to ptovide support from the 

USGS for the continued appraisal of domestic potential uranium 

resources needed for the EIA's work in reporting the viability of 

the U.S. uranium industry under Public Law 97-415. 

PURPOSE 

The purpose of this MOU is threefold: (1) to identify areas of 

support from the USGS for programs of the EIA relating to the 

ongoing study of the viability of the domestic uranium industry 

and the compilation of information on nuclear energy minerals for 

u1ternational program activities; (2) to define areas of 

cooperation between the EIA and the USGS concerning the mutual 

sharing of data on the uranium industry; and (3) to 

differentiate clearly the responsibilities of the agencies in the 

areas of cooperation and work discussed herein. 

23 
OBJECTIVE 

~he inten~ of thii MOU is to comply with the requirement, stated 

ln a prevlous MOU between the DOE and the DOI, that follow-on 

work, including potential uranium resource appraisal work 

required to meet objectives of the industry viability study, is 

to be conducted by the USGS consistent with the availability of 

its funds. The intent also is to describe the kinds and degrees 

of the USGS support foreseen for the EIA's programs. Specific 

details not addressed herein that relate to technical aspects of 

cooperation and conduct of the work shall be formalized in 

writing as necessary between the EIA and the USGS. 

Under this agreement, there are to be no duplications by the EIA 

or the USGS of the functions vested in either organization and 

required by statute, nor is any abrogation of the provisions of 

the prior MOU signed by the Secretary of the DOE and the 

Secretary of the DO! intended. 

SCOPE 

The scope of this agreement is limited to: (1) data developed at 

the GJAO under the URA program for the appraisal of domestic 

uranium endowment and potential uranium resources, including the 

computerized Uranium Resource Appraisal Data (URAD) , the map data 

of potential urunium resource areas, and the supporting software 

for these two data bases; and (2) data for potential uranium 

resource appraisal purposes compiled from industry-supplied, 

company-confidential data aggregated to prevent disclosure of 

company-specific information and added to the URA data set by the 

EIA. Proprietary data on commercial activities of the uranium 

industry collected by the EIA through the U.S. Uranium Industry 

Annual Survey ure expressly excluded fr6m the purview of this 

agreement. 

CONDUCT OF FOLLO\·~-ON POTENTIAL RESOURCE h.PPRAISAL \'"'ORK 

The principal support required from the USGS is ~o provide 

estimations of the conditional uranium endovnnent for use in the 

calculation of potential uranium resources using the DOE standard 

methodology. The DOE estimates of potential resources currently 

1 "Hemorandum of Underst.:1nding betv.'een (the) Department of 

Energy and the Department of the Interior Implementing the 

Transfer of Responsibilities for Maintenance of Data Collected 

Under the National Uranium Resource Evaluation (NURE) Program and 

Providing for the Continuing Assessment of the Nation's Uranium 

Resources." The !-lOU v.ras signed by the Secretary of Energy on 

November 30, 1983, and by the Secretary of Interior on January 13, 

19 84 . 

2

c on d it ion a l uranium en do\·lme n t is ex p lain e d in the Appendix . 

24 
are derived through a formally structured subjective-probability, 

geological-analogy procedure (the DOE standard methodology) which 

incorporates steps to minimize biases in the estimated totals. 

The estimates of U.S. potential uranium resources, covering as of 

January 1, 1984, over 700 individual estimates, are rooted in the 

standard methodology with its attendant assumptions which permit 

statistical analysis of these resource data. 

Follow-on work to update these estimates should follow the 

standard methodology to permit ready entry of the new data into 

the DOE's automated, potential-resource data base and the 

subsequent use of all those data in analysis and reporting of 

U.S. resource totals as expected quantities (mean values) of 

corresponding aggregate probability distributions at specified 

confidence levels. In estimating the conditional uranium 

endowment, the USGS will modify the calculation of "F," the 

fraction of a favorable area believed to be underlain by uranium 

endowment, so that the geological data and judgments of the USGS 

are mathematically described and verified to the satisfaction of 

both the EIA and the USGS consistent with the standard 

methodology. This procedure will assure the integrity of the 

DOE's URA data set, the USGS parameters for uranium endowment, 

and the reliability/comparability of future published U.S. 

uranium resource estimates. The use of the standard methodology 

and existing computerized procedures also will provide the EIA 

with access to the most recent potential resources data as 

stipulated in the previous MOU (see Footnote 1 on page 1). 

Computerized resource data files and programs, which were 

developed jointly by the Oak Ridge National Laboratory and the 

GJAO for the computation of uranium endowment and potential 

resources, are operational, and these procedures can be used in 

the follow-on resource appraisal work. A process will be 

developed through discussions with the USGS whereby its personnel 

will be able to use these resource data and computational 

procedures interactively as an aid in developing their own 

resource estimates. 

A. Selection of Potential Resources Study Areas 

The EIA and the USGS by mutual agreement shall compile annually 

a slate of prospective potential resource areas, wherein it is 

deemed that additional or new geological studies are warranted 

based on the availability of new data or on reinterpretations of 

existing data. The slate of areas for a given work year should 

be prepared sufficiently early to permit geological studies in 

the areas to be completed, estimations of the areas' uranium 

resources completed, and the resulting new resource data entered 

in the DOE dat3 files during the same work year. Major emphasis 

shall be given to the selections of uranium resource areas for 

which studies likely will result in significant modifications in 

the nation's uranium resource totals, i.e., by increasing or 

25 
decreasing resource estimates by 500 tons u1oR or more per area. 

Exceptions would be areas not previously assessed and areas 

currently assigned a small potential resource that, based on 

current analysis, possibly should be deleted. 

B. Access to the DOE Potential Resources Data Bases 

The DOE potential resources data currently are collected into two 

computerized data bases. The assessment data base contains 

information on regional totals for uranium reserves in the 20 

U.S. resource regions and the approximately 700 potential 

resource assessments spanning the DOE classes of probable, 

possible, and speculative. Access by the USGS to this data base, 

formally named the Uranium Resource Appraisal Data (URAD) , and 

its supporting software shall be provided by the EIA. The map 

data base contains labels and digitized areas data for both 

assessed (potential resource) areas and unassessed areas 

delineated by the field geologist who studied these areas. Under 

the current plan for follow-on resource appraisal work, the map 

data base and supporting automated procedures will be archived in 

the EIA's computer facility for possible future applications. 

The map data, program procedures, and compilations of maps of 

potential resources data shall be available to the USGS. 

C. Derivation of Potential Resource Estimates 

The standard methodology shall be utilized in deriving estimates 

of potential resources from new conditional uranium endowment 

data to assure their comparability with the DOE existing 

potential resource estimates and that the resulting data can be 

aggregated to form national resource totals. 

D. Modifying the DOE Potential Resources Data Files 

Proposed changes to add new resource data or to update existing 

resource data shall be approved by designated EIA and USGS staff 

prior to the adoption of the changes. This arrangement will 

prevent unauthorized modifications and assure the entry of 

correctly encoded data. Standard NURE codes shall be used to 

enter new data into the data bases. A manual of current listings 

of the standard DOE codes shall be provided by the EIA. The 

reporting of new data on conditional uranium endo\·nnent and backup 

information (Parts I, II, and III on the DOE UR-85 data input 

form, January l, 1984; see the Appendix, Figure 1) developed by 

the USGS shall consist of the entry of proper data into the 

assessment (URAD) data base. A manual covering the use of the 

assessment data files shall be provided by the EIA. The adding 

of new uranium endowment data shall be completed at specified 

times during the year so that timely, current listings 

26 
of the nation's uranium potential can be obtained in support of 

the EIA reports mandated by Public Law 97-415 and to meet other 

needs. A schedule of times for adding the new data will be 

developed and approved jointly by the EIA and the USGS. 

For new or revised estimations of uranium endowment, a map(s) 

showing the outline for each favorable area(s) (corresponding to 

the parameter "A" in the endowment equation, Ue = A·F·T·G) shall 

be provided by the USGS to the EIA to permit the compilation of 

an updated map of U.S. resource areas for use by the EIA, USGS, 

and other agencies. 

E. Classification of the EIA Potential Resource Estimates 

The DOE classification scheme for potential resources shall be 

used for categorizing new and revised resource estimates. This 

classification encompasses the classes of probable, possible, and 

speculative potential uranium resources and the correspo~ding 

definitions as publ~shed in the DOE's report GJ0-100(83) and the 

report GJ0-111(80). In addition, probable potential resources 

will be further delineated into two subcategori5s, designated as 

Estimated Additional Resources (EAR}-I and -II. Standardization 

to this classification scheme will assure comparability between 

future published totals, those developed under the NURE Program, 

and those required under Section G below. 

F. Sharing of Company-Confidential Data 

Hany of the company-specific uranium resource data that \vere 

received by the EIA under the transfer of the URA function from 

the GJAO are proprietary, company-confidential data. Certain of 

these company-specific data will be useful to the USGS in 

conducting its work on appraising uranium endowment. Similarly, 

certain confidential data held by the USGS might be useful in the 

conduct and reporting of the EIA work. It is the intent of this 

agreement that only the URA data, as described in the SCOPE 

section above, and the uranium resources data held by the USGS 

shall be shared by the DOE and the USGS. 

3u.s. Department of Energy, Statistical Data of the Uranium 

Industry, GJ0-100 {83), Grand Junct1on, Colorado, Grand Junction 

Area Office, U.S. Department of Energy, 1983, p.15. 

4 U.S. Dep.:1rtrnent of Energy, An Assessment Report on Uranium in 

the United St2tcs of America, GJ0-111 {80), Grand Junction Area 

Office, U.S. Department of Energy, 1980, p.21. 

5 Nuclear Energy Age11cy ~ . l . E A ana Internat1ona Atom1c nergy gency, 

Uranium: Resources, Production and Demand, Organization for 

Economic Cooperation and Development, Paris, France, 1984. 

27 
1. Data shared between the DOE and the USGS which are marked as 

company confidential are to be considered as proprietary and 

are for official, programmatic use only, and they shall be 

divulged to a party outside of the Federal Government only 

with the written consent of the company/individual which 

provided the data, or in accordance with the law. 

2. Before publishing or disseminating any aggregations based 

on the data transmitted under this agreement, each agency 

agrees to consult with and obtain the concurrence of the 

agency that originated the data on which the aggregation 

is based. Such aggregated data, which are based on 

company-confidential data, may be released only when they 

are in such a format that the identity of any portion of 

the data attributable to any specific firm is not revealed. 

3. In all cases, care shall be given to the assurance that 

there are adequate physical and procedural safeguards to 

protect the proprietary nature of any data shared between 

the EIA and the USGS from inadvertent disclosure. 

4. Each agency shall refer for response any request for data 

transmitted under this agreement to the agency that 

originated such data, including any request from the General 

Accounting Office, the Congress or any duly established 

committee of Congress, or other Congressional agency. 

5. Upon notification that a Court Order requiring disclosure of 

the data transmitted under this agreement will be or has 

been sought, the USGS agrees to: (a) consult with the EIA 

to determine whether arguments against disclosure of the 

data should be presented to the court, in the first 

instance, and, in any event, seek a protective order'that 

preserves the confidentiality and limits the use of further 

disclosure of the proprietary data; and (b) afford the EIA 

an opportunity to review and comment on the terms of the 

proposed protective order. In the event that the court 

issues an order requiring disclosure of the data, the USGS 

will provide the EIA and the originators of the data with 10 

days written notice prior to disclosure, or, alternatively, 

as much advance notice as can reasonably be provided under 

the circumstances. At the time of such disclosure, the USGS 

will advise those persons receiving the data, that the data 

were obtained by the EIA from respondents for statistical 

purposes and that the EIA and the respondents consider the 

data to be proprietary business data. The EIA, in turn, 

agrees to comply with these procedures regarding court 

orders affecting any data it receives under this agreement 

from the USGS. 

28 
G. Compilation of Nuclear Energy Minerals Information for 

International Program Activities 

Nuclear energy minerals pertinent to international program 

activities are primarily uranium and secondarily thorium. The 

resources of these minerals are reported every two years by the 

Organization for Economic Cooperation and Development's Nuclear 

Energy Agency (NEA) and the International Atomic Energy Agency 

(IAEA) in a joint report, commonly called the Red Book, entitled 

"Uranium: Resources, Production and Demand." The Red Book 

contains text and statistics on U.S. uranium resources, 

production, and demand. It also contains a section on U.S. 

resources of thorium. 

In the past, the DOE has provided the necessary information on 

U.S. uranium resources for the Red Book publication, and the USGS 

has contributed some geologic data on uranium and nearly all of 

the geologic and resource data on thorium. In the future, 

compilations of information on uranium and thorium will be 

performed cooperatively by the DOE and the USGS under the 

following arrangement: 

(a) nongeological data on uranium resources will be supplied 

by the DOE, 

(b) geological information on uranium will be supplied by 

the USGS, 

(c) all information on thorium resources will be supplied by 

the USGS, and 

(d) the submission of all final U.S. data and information 

on uranium and thorium will be coordinated by the DOE. 

To ensure consistent and useful information for the Red Book, 

both agencies will have a representative on the NEA/IAEA Working 

Party on Uranium Resources with the DOE representative serving as 

the head of the delegation, while the USGS and the U.S. Bureau of 

Mines would participate in all international activities related 

to uranium geology, for example in the work of the Joint Group of 

Experts on Research and Development in Uranium Exploration 

Techniques and the Working Group on Uranium Extraction. The DOE 

will continue to represent the United States at the joint 

NEA/IAEA Steering Group on Uranium Resources in dealing with the 

~LA and the IAEA. 

APPLICATION OF ALTERNATE POTENTIAL RESOURCES DERIVATION AND 

CLASSIFICATION 

In the preceding sections of this MOU, general procedures have 

been described that will permit the continued derivation of 

29 
annual estimates of U.S. potential uranium resources through 

application of the DOE methodology with new data on conditional 

uranium endowment from the USGS, the use of the URAD data files 

and the supporting computerized procedures for data storage, 

computation, and retrieval. Justification for this approach is 

given above. 

The proposed approach should be viewed as an interim one, 

because, with the close-out of the NURE program at the GJAO and 

the shifting of the responsibility for the study of uranium 

deposits and the determination of uranium endowment from the DOE 

to the USGS, a different set of emphases and concerns have 

emerged relative to the carrying forward of a U.S. potential 

resource appraisal effort under a new, practical, and viable 

program. The development and application of resource-estimation 

procedures that incorporate current knowledge and 

state-of-the-art technology from mathematics, geology, and other 

disciplines to construct reliable appraisals of undiscovered 

natural resources is a continuing goal. The work now is to be 

carried forward with fewer monetary and personnel resources than 

were available during the NURE program. 

The development and application of modified or alternate uranium 

endowment and resource appraisal procedures shall be encouraged 

under this MOU to ensure that state-of-the-art techniques and 

knowledge are used in the follow-on work. The feasibility of 

incorporating new procedures into the standard methodology shall 

be decided jointly by the EIA and the USGS. In a similar manner, 

the investigation of modified or alternative resource 

classification schemes shall be encouraged. 

MANAGE!•1ENT ARRANGEMENTS AND REVIEW OF FOLLOh'-ON RESOURCE 

APPRAISAL h'ORK 

Direct communication between the DOE and the USGS program 

officials designated as responsible for the performance of the 

cooperative work under this MOU is anticipated. Letters between 

the agencies describing project plans in appropriate detail will 

serve as program documentation for work arrangements as may be 

required in the implementation, coordination, and conduct of the 

work. 

An oversight committee, consisting of designated officials from 

each agency, shall meet periodically--quarterly or less 

frequently as required--to review accomplishments and the status 

of the follow-on work, and to discuss program guidance and the 

adequacy of the work in meeting the needs of the respective 

agencies' programs. 

30 
A. Public Information Coordination 

Upon receipt of any request made under the Freedom of Information 

Act (5 U.S.C., paragraph 552(b)), each agency shall respond with 

regard to that portion of the data that was originated by that 

agency. Decisions concerning the disclosure of any information 

developed jointly by the USGS and the EIA shall be determined 

jointly between appropriate representatives of the EIA and the 

USGS. 

B. Amendment and Termination 

This MOU may be modified or amended by written agreement between 

the EIA and the USGS, and it may be terminated by mutual 

agreement of the EIA and the USGS or unilaterally by either party 

upon a 60-day written notice to the other. 

C. Effective Date 

This MOU is effective upon the date of final signature. 

U.S. GEOLOGICAL SURVEY 

U.S. DEPARTMENT OF THE INTERIOR 

Dallas L Peck 

(Signature) 

(Title) 

SEP 2 0 1984 

(Date) 

31 

ENERGY INFORMATION 

AD!-1INISTRATION 

U.S. DEPARTMENT OF ENERGY 

,, ;,L ~ ~tl\9)) {r' (Signature 

Administrator 

Energy Information Administration 

(Title) 

(Da~e) 

J::i. U.S. GOVERNMENT PRINTING OFFICE:1987-573-047/66009