United States Office of Radiation Programs ORP/LV-80-1
Environmental Protection Las Vegas Facility January 1980
Agency P.O. Box 18416
Las Vegas NV89114
Radiation
&EPA Particle Size Distribution
of Yellowcake Emissions
at the United Nuclear-
Churchrock Uranium Mill
-------
PARTICLE SIZE DISTRIBUTION OF YELLOWCAKE EMISSIONS
AT THE UNITED NUCLEAR-CHURCHROCK URANIUM MILL
C. W. Fort Jr.
R. Douglas
R. Gauntt*
A. R. McFarland*
Consultants
January 1980
United States Environmental Protection Agency
Office of Radiation Programs - Las Vegas Facility
Las Vegas, Nevada 89114
-------
DISCLAIMER
This report has been reviewed by the Office of Radiation Programs -
Las Vegas Facility, U.S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for their use.
-------
PREFACE
This study was conducted by the Office of Radiation Programs - Las Vegas
Facility (ORP-LVF) of the U.S. Environmental Protection Agency. The purpose
of the study was to evaluate the particle size distribution of yellowcake
(uranium concentrate) emissions from the yellowcake processing stacks at a
uranium mill. This is one of a series of similar studies that are being
conducted at several uranium mills.
As a follow-on study to yellowcake emission rate tests at six uranium
mills, this work supports the requirements of Section 122 of the Clean Air Act
Amendments of 1977, Public Law 95-95. Section 122 directed EPA to review all
relevant information and determine if emissions of radionuclides cause or
contribute to air pollution. The uranium milling industry is one of the
source categories being considered by the Office of Radiation Programs in
implementing the Clean Air Act.
The field work for this study was conducted by Mr. Charles W. Fort with
the assistance of Mr. Richard Douglas. The samples were analyzed by Dr. Emil
Kalil at Uranium-West Laboratories. Following initial analysis of the
resulting data by Mr- Fort, Dr. Andrew McFarland, consultant to ORP-LVF, and
Mr. Randy Gauntt performed the final data analysis and report preparation.
Dr. McFarland is a Professor of Civil Engineering at Texas A&M University and
Mr. Gauntt is a research associate at Texas A&M.
We would appreciate receiving any comments on this report that readers may
have to offer.
Donald W. Hendricks
Director, Office of
Radiation Programs, LVF
-------
ABSTRACT
Tests were conducted to characterize the particle size distribution of
yellowcake dust from the packaging and dryer stacks of a uranium mill in New
Mexico. A multistage inertia! impactor was used to sample the particulate
matter to provide a basis for determining particle size distributions and
emission rates. The principal results, from four tests with the packaging
stack and eight tests with the dryer stack, are as follows:
Parameter Packaging Stack Dryer Stack
Mass median aerodynamic
particle diameter 1.62 ym 1.19 ym
Respirable fraction
(Utot activity associated
with sizes 1 2.5 ym) 69% 90%
Concentration of 558 ± 192 pCi/dscm 6120 ± 1070 pCi/dscm
Utot (equivalent (0.971 ± 0.335 mg/dscm) (10.7 ± 1.86 mg/dscm)
in stack
Total emission rate 1.19 ± 0.397 yCi/hr 62.5 ± 15.8 yCi/hr
of Utot (equivalent (2.07 ± 0.692 g/hr) (109 ± 27.1 g/hr)
-------
CONTENTS
Page
PREFACE iii
ABSTRACT iv
LIST OF FIGURES vi
LIST OF TABLES vi
LIST OF ABBREVIATIONS AND SYMBOLS vi i
ACKNOWLEDGMENTS viii
INTRODUCTION 1
SAMPLING METHODOLOGY 3
ANALYSIS AND RESULTS 5
SUMMARY AND CONCLUSIONS 13
REFERENCES 15
APPENDICES
A -- Basic Impactor Data A-l
B -- Summary of Size Parameters and Total Mass for
Individual Tests B-l
C -- Composite Size Distribution Data C-l
D -- Example of Calculations for Determination of
Particle Concentration and Emission Rate D-l
-------
LIST OF FIGURES
Number Page
1. Cumulative Size Distribution of Yellowcake Particles
in Packaging Stack 6
2. Cumulative Size Distribution of Yellowcake Particles
in Dryer Stack 7
3. Mass Frequency of Particulate Matter from Packaging Stack 11
4. Mass Frequency of Particulate Matter from Dryer Stack 12
LIST OF TABLES
Number Page
1. Test Parameters and Information 8
2. Emission Characteristics of Packaging and Dryer Stacks 9
3. Summary of Emission Characteristics for Individual Tests 14
-------
LIST OF ABBREVIATIONS AMD SYMBOLS
A combination of both English units and the International System of Units
(SI) are used in this report. For the most part the units dealing with mass
and particle size follow SI; however, since gas flow rates are typically
measured in the English system, certain flow parameters are expressed corre-
spondingly. In addition, gas volumes can be presented either dry or moist. A
summary of the special gas volume, flow rate, and radioactivity units and
abbreviations used herein follows:
acf = actual cubic feet. The units of gas volume that include the
moisture component and that correspond to the actual pressure
and temperature of the gas.
dscf = dry standard cubic feet. Gas volume, with moisture fraction
removed, that would exist if the temperature were 68°F and
the pressure were 29.92 in. Hg.
acfm = actual cubic feet per minute. Units of volumetric flow rate
of gas based on actual conditions.
dscfm = dry standard cubic feet per minute. Flow rate of gas that
would exist if moisture were deleted and if temperature and
pressure were as given above for units of dscf.
dscm = dry standard cubic meters. Identical to dscf except converted
to SI. 1 dscm = 35.3 dscf.
utot = total uranium activity, i.e., the sum of U-238, U-234, and
U-235 activities.
pCi = picocurie = 10~12 curie.
ym = micrometer = 10-6 meter.
-------
ACKNOWLEDGMENTS
The authors wish to express their appreciation to Dr. Noel Savignac,
United Nuclear Corporation - Albuquerque, and Mr- Todd Miller and his staff at
the United Nuclear Churchrock uranium mill in Churchrock, New Mexico for the
assistance and cooperation they extended during this study.
vm
-------
INTRODUCTION
From May 16 to May 21, 1979, a series of tests were conducted to determine
the size distributions of the yellowcake* particles vented from the dryer and
packaging stacks at the United Nuclear Corporation uranium mill near
Churchrock, New Mexico. The exhaust gases from both the packaging and dryer
operations are passed through air pollution control equipment before being
discharged through the stacks. A Joy venturi wet scrubber is used on the
packaging gases and a Sly "Impi-Jet" scrubber is used for the dryer stack.
The basic sampling tool used in these tests was an eight-stage inertial
impactor fitted with an after-filter (Andersen, 1977). This device collects
particles in a manner compatible with determining the mass distributions of
particles as a function of aerodynamic diameter (Da)-**
EPA is considering the adoption of size standards for airborne particulate
matter (Miller et al., 1979). Recommended is a standard based on inhalable
particulate matter defined as _<15 ym with emphasis also on the <2.5 ym
fraction. Particles in this latter size range are capable of penetrating the
gas-exchange region of the lower respiratory tract and will be referred to in
this report as respirable particulate matter.
* Yellowcake is the generic name given the packaged uranium concentrate
produced by uranium mills. It is generally a dry, powdery material having a
variety of chemical forms ranging in color from bright yellow through olive
green to black, depending on each mill's process. The uranium content of
yellowcake is typically expressed as an equivalent mass of one of these
compounds, UsOg, as in this report. However, since the chemical form of
the United Nuclear yellowcake is unknown, it is important for the reader to
realize this material may not be UsOg or have the solubility character-
istics of 0303.
** Aerodynamic diameter relates the aerodynamic behavior of irregularly shaped
particles with varying densities to the diameter of a unit density spherical
particle that would behave identically under the same conditions. All
particle size references in this report are to aerodynamic diameters.
-------
Data from an inertia! impactor can be used to characterize the respirable
fraction. However, the inertia! impactor used in these studies does not
does not provide size resolution for particles larger than approximately
10 yin. Highly definitive information, therefore., is not obtainable on
material in the inhalable/non-inhalable fractions.
-------
SAMPLING METHODOLOGY
Four sampling locations at 90° intervals (one in each of the four
quadrants) were used for the dryer stack. Prior to each test, the velocity
distribution for the quadrant of interest was determined with a pi tot tube
(USEPA, 1977). A sampling point was selected corresponding to the location at
which the dynamic pressure was equal to the average pressure for that
quadrant. By coincidence, each of the four sampling points was 3.4 inches
from the stack wall. Duplicate tests were conducted at each of the four
points. The inside diameter of the stack is 33.5 inches.
The packaging stack, which is 11.25 inches in diameter,, would not
accommodate the entire impactor without causing undue flow blockage; there-
fore, the criterion for location of a sampling point was that the impactor be
inserted into the stack to a depth whereby the flow blockage would be less
than 2 percent. Two locations were used with the points 90° apart and 3.75
inches from the wall. Duplicate tests were conducted at each of the two
points.
In preparation for a test, glass fiber collection substrates and a glass
fiber after-filter were placed in the impactor, and the impactor was then
inserted into the stack. The unit was equipped with heater tapes to enable
the impactor to operate well above the stack dew-point temperature. Before
sampling began, the impactor was allowed to equilibrate with the stack
temperature for 30 minutes. The sampling flow was then started, and sampling
continued for a period of 30 to 75 minutes.
At the completion of particle collection, the impaction substrates and
after-filter were removed and sent to Uranium-West Laboratories (15515 Sunset
Blvd., Suite B07, Pacific Palisades, California 90272) for determination of
the total' uranium deposited on each element. Samples were analyzed by a
delayed-neutron counting technique. This method has a detection sensitivity
of 0.17 pCi Utot (0.25 ygm Utot).
-------
A program was developed for the Hewlett Packard 97 calculator (Fort, 1979)
to compute impactor stage cut-points. The program incorporates the effects of
such sampling variables as flow rate, temperature and pressure as well as the
most current impactor calibration data published by Gushing et al. (1976).
The program has been validated through an independent cross-check (McFarland,
1979).
-------
ANALYSIS AND RESULTS
The basic test parameters and variables are summarized in Table 1. For
each test, the sampler was operated for a period of 30-75 minutes at a flow
rate of approximately 0.5 acfm. Total flow rate through the packaging stack
ranged from 1217 to 1275 dscfm and through the dryer stack from 4930 to 7130
dscfm.
The particle size data from use of the inertial impactor are tabulated in
Appendix A, where the quantity of uranium associated with each stage of the
impactor is given as a function of the cut-point particle size of the stage
(aerodynamic particle diameter for which the particular impactor stage has a
50 percent collection efficiency). For example, in Test A of the packaging
stack, 90.4 yg of uranium was collected on the stage that has a cut-point of
11.0 ym. Similarly, 1.7 yg was collected on the stage with a cut-point of
10.2 ym. Thus, of the material collected during Test A, 90.4 yg of uranium
had aerodynamic sizes O.1.0 ym, and 1.7 yg had aerodynamic sizes between 10.2
and 11.0 ym.
Normalized cumulative size distributions were calculated for each test.
The results for the packaging stack are plotted in Figure 1 and those for the
dryer stack in Figure 2. Smooth composite curves fitted through the data
points can be used as a basis for estimating the mass median aerodynamic
particle size (corresponding to the 50th percentile) and the fraction of
material in the respirable range. These values (Table 2) show the mass median
sizes to be 1.62 and 1.19 ym for the packaging and dryer stacks, respectively.
The corresponding values for the respirable fractions are 69 and 90 percent.
Cumulative distributions for the individual tests were also plotted, and
determinations were made of the mass median sizes and the respirable
fractions. A summary of these data appears in Appendix B.
-------
AERODYNAMIC ARTICLE DIAMETER, DQ ,
FIGURE 1. CUMULATIVE SIZE DISTRIBUTION OF YELLOWCAKE PARTICLES
IN PACKAGING STACK
-------
100
5 vi
, W
Li- UJ
O N
CO W
™ Q
. UJ
UJ
O O
o: o
UJ
-------
TABLE 1. TEST PARAMETERS AND INFORMATION
CO
Stack
Packaging
Dryer
Test
A
B
C
D
E
F
G
H
I
J
K
L
Sampling
Point
1
1
2
2
1
1
2
2
3
3
4
4
Test
Time
Minutes
45
60
60
75
60
75
30
30
45
30
30
30
Temperature
(degrees F)
91
77
77
84
132
166
152
139
146
154
139
140
Fl ow Rate
(acfm)
0.507
0.520
0.532
0.539
0.419
0.419
0.594
0.601
0.502
0.495
0.536
0.498
• Stack Moisture
Mol Fraction
0.029
0.026
0.025
0.027
0.060
0.060
0.060
0.058
0.060
0.058
0.051
0.070
Stack Flow
Rate (dscfh)
1217
1260
1265
1275
4970
4930
7020
7130
5830
5700
6320
5830
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TABLE 2. EMISSION CHARACTERISTICS OF PACKAGING AND DRYER STACKS
Parameter
Packaging Stack
Dryer Stack
Mass Median Aerodynamic
Diameter
1.62 urn
1.19 ym
Average Respirable
Fraction
0.688
0.902
Geometric Mass Mean
Aerodynamic Diameter
2.19 ym
1.28 ym
Geometric Standard
Deviation
2.95
1.92
Total Concentration
of Utot,
(U308)*
558 ± 192 pCi/dscm
(0.971 ± 0.335 mg/dscm)
6120 ± 1070 pCi/dscm
(10.7 ± 1.86 mg/dscm)
Respirable Concentration
of
(U308)
Average Emission Rate
of Utot>
CU308)
382 ± 123 pCi/dscm
(0.665 ± 0.215 mg/dscm)
1.19 ± 0.397 yCi/hr
(2.07 ± 0.692 g/hr)
5750 ± 760 pCi/dscm
(10.01 ± 1.32 mg/dscm)
62.5 ± 15.8 yCi/hr
(109 ± 27.1 g/hr)
Average Respirable Emission
Rate of Utot> °-812 ± °-253
(1.41 ± 0.441 g/hr)
56.3 ± 14.2 yCi/hr
(98.1 ± 24.7 g/hr)
'Quantities in parentheses represent Utot expressed as equivalent
** Error terms are one standard deviation of replicate tests.
-------
I he composite curves. Figures 1 and 2, were each divided into size inter-
vals of approximately equal logarithmic increments, Aln(D), and derivative
approximations at the interval midpoints (geometric means) were formed as
AG(D)/Aln(D), where AG(D) represents the difference of the cumulative distri-
bution values at the interval upper and lower particle size boundaries. The
results of this procedure appear in Appendix C and are plotted in Figures 3
and 4 as AG(Da)/AlN(Da) versus aerodynamic diameter, Da. Since the
irnpactor does not provide information on the distribution of particles with
sizes greater than approximately 10 ym, an upper boundary size was assumed
for the largest fraction. The values selected were 20 ym for the packaging
stack and 13 urn for the dryer stack data. The bimodal appearance of these
mass densities may be due, in part, to the selection of the upper limit of the
largest size interval; however, the plot of the packaging stack data, Figure
3, illustrates that considerable material is associated with particle sizes
_<10ym. Figure 1 shows that approximately 20 percent of the uranium mass from
the packaging stack is associated with these larger sizes. Correspondingly,
only 5 percent of the uranium mass collected from the dryer stack is seen to
be associated with particles larger than 10 ym.
The geometric mass mean aerodynamic diameter, Dg, and the geometric
standard deviation, sg, for the distributions in Figures 3 and 4 were
computed using:
In Dg = z (In Di} mp) * AGj
where D-j jfnp = midpoint size of ith interval
Di,mp = (Di,u * DijL)1/2
DI,U = interval upper boundary
^i,L = interval lower boundary
and:
In2 sg = i (In Di5mp - In Dg)2 * AGi (McFarland,1978)
in conjunction with the data tabulations of Appendix C. The results are given
in Table 2,
10
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AERODYNAMIC PARTICLE DIAMETER, D ,
FIGURE 3. MASS FREQUENCY OF PARTICIPATE MATTER FROM PACKAGING STACK
-------
AERODYNAMIC PARTICLE DIAMETER, DQ ,
FIGURE 4. MASS FREQUENCY OF PARTICULATE MATTER FROM DRYER STACK
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Using the procedure outlined in Appendix D, total concentrations and
respirable concentrations were computed for each test. Concentrations were
calculated in terms of pCi Utot/dscm and mg UsOg/dscm. Total and re-
spirable emission rates (pCi Utot/nr and g UsOs/hr) were then calculated
for each test using the dry standard concentrations and the dry standard stack
flow rates. The basic assumptions used in calculating emission rates from
impactor data are (1) a homogeneous yellowcake concentration exists throughout
the stack, and (2) the gas velocity at the sampling point is the average
velocity for the stack. These results are summarized by test in Table 3. The
values of the parameters for each stack in Table 3 were averaged, and a stand-
ard deviation was calculated. These values are listed in Table 2.
SUMMARY AND CONCLUSIONS
The yellowcake particle emissions from the uranium mill packaging and
dryer stacks can be characterized by mass median aerodynamic diameters of 1.62
and 1.19 ym, respectively. If respirable particulate matter is defined as
particles with aerodynamic sizes <2.5 ym, then the packaging stack has a
respirable fraction of 69 percent while that of the dryer is 90 percent.
Since both stacks are controlled with scrubbers, the actual size distributions
and respirable fractions are quite dependent upon the scrubber performance.
Approximately 20 percent of the particulate mass emitted by the packaging
stack was associated with aerodynamic particle sizes larger than 10 ym. A
scrubber should efficiently remove these larger particles from the distribu-
tion, so it appears that the packaging stack scrubber may have abnormal mist
carryover or may have other operational or design problems.
The packaging stack discharges an average of 1.19 yCi Ut0t/hr (2.07 g
UsOs/hr) to the atmosphere. The rate for the dryer stack is 62.5 yCi
Utot/hr (109 g U308/hr).
13
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TABLE 3. SUMMARY OF EMISSION CHARACTERISTICS FOR INDIVIDUAL TESTS
Stack
Packaging
Dryer
Test
Number
A
B
C
D
E
F
G
H
I
J
K
L
Total Uranium
Concentration
626.23
767.44
527.51
310.53
4760.76
6266.36
6706.62
6272.10
6351.88
7475.20
6813.95
4287.78
Respirable Uranium
Concentration
(pci Ut0t/dscm)
456.90
491.34
363.92
214.68
4047.85
5827.25
6035.61
5707.86
5778.46
6727.85
6063.74
5772.14
Total Uranium
Emission Rate
(yCi Utc,t/hr)
1.296
1.636
1.138
0.679
40.161
52.521
79.958
76.026
62.949
72.391
73.128
42.495
Respirable Uranium
Emission Rate
(yCi Utot/nr)
0.946
1.047
0.785
0.468
34.137
48.739
71.962
68.804
57.283
65.152
65.230
39.095
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REFERENCES
Andersen 2000, Inc. (August 1977). Operating Manual for Andersen 2000, Inc.:
Mark II and Mark III Particle Sizing Stack Samplers. Atlanta, Georgia.
Gushing, K. M., G. E. Lacey, 0. D. McCain and W. B. Smith (October 1976).
Particulate Sizing Techniques for Control Device Evaluation: Cascade
Impactor Calibrations. Ind. Env. Res. Lab., U.S. EPA, Research Triangle
Park, N.C. and Southern Research Inst., Birmingham, Alabama. Contract No.
EPA-68-02-0273. EPA 600/2-76-280.
Fort, C. W. (1979). "Impaction Stage Cut-point Calculations for the
Anderson Mark III Impactor." An original program for the Hewlett Packard 97
calculator (unpublished).
McFarland, A. R. (March 1978). Aerodynamic Particle Sizing Air Quality
Laboratory Publication, Texas ASM University.
McFarland, A. R. (1979). Personal Communication.
Miller, F. J., D. E. Gardner, J. A. Graham, R. E. Lee, Jr., W. E. Wilson, and
0. D. Bachmann (1979). "Size Considerations for Establishing a Standard for
Inhalable Particles," Journal of the Air Pollution Control Association,
29, 6, (June 1979), pp 610-615.
U.S. EPA, (August 18, 1977). Standards of Performance for New Stationary
Sources: Method 1 Sample and Velocity Traverses for Stationary Sources.
Federal Register, 42, 160.
15
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APPENDIX A
Stack
Packaging
Packaging
Packaging
Packaging
Basic Impactor Data
Sampling Impactor Aerodynamic
Test Point Cut-Point Size, um
A 1 11.0
10.2
6.4
4.3
2.3
1.1
0.65
0.36
0 (Filter)
B 1 10.8
10.0
6.2
4.2
2.3
1.1
0.64
0.35
0
C 2 10.6
9.9
6.2
4.2
2.2
1.0
0.63
0.35
0
D 2 10.6
9.9
6.2
4.2
2.2
1.0
0.63
0.35
0
Uranium
Collected,yg
90.4
1.7
9.0
13.0
48.5
285.4
80.2
24.8
5.8
166.8
10.4
37.8
37.1
118.2
358.3
151.8
58.8
24.6
137.1
3.2
11.9
12.6
70.3
265.7
112.3
41.3
23.2
84.5
4.1
16.2
15.4
52.2
179.6
77.6
37.4
31.0
A-l
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APPENDIX A (continued)
Basic Impactor Data
Stack
Dryer
Dryer
Dryer
Dryer
Sampling Impactor Aerodynamic
Test Point Cut-Point Size, um
E 1 12.5
11.6
7.2
4.9
2.6
1.2
0.74
0.41
0
F 1 12.7
11.8
7.4
5.0
2.7
1.2
0.75
0.42
0
G 2 10.6
9.8
6.1
4.1
2.2
1.0
0.61
0.33
0
H 2 10.4
9.7
6.0
4.1
2.2
1.0
0.60
0.33
Uranium
Collected.ua
0*
186.8
16.0
55.2
336.7
1442.4
1014.5
872.0
295.5
87.4
16.1
24.7
35.0
182.9
2544.4
2277.7
1160.1
268.8
89.6
23.4
31.8
52.0
316.9
2338.4
966.0
227.1
28.9
34.3
11.8
22.4
40.4
338.2
2343.6
936.6
182.3
0 26.7
*Uranium on first impactor stage combined with second stage.
A-2
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APPENDIX A (continued)
Basic Impactor Data
Stack
Dryer
Dryer
Dryer
Dryer
Sampling Impactor Aerodynamic
Test Point Cut-Point Size,- um
I 3 11.5
10.6
6.6
4.5
2.4
1.1
0.67
0.37
0
J 3 11.6
10.8
6.7
4.5
2.4
1.1
0.68
0.37
0
K 4 11.1
10.2
6.4
4.3
2.3
1.1
0.64
0.35
0
L 4 11.5
10.6
6.6
4.5
2.4
1 .1
0.67
0.37
0
Uranium
Collected, UQ
163.9
17.1
22.8
30.8
222.5
2401 .1
1450.0
546.5
74.5
163.5
14.8
21.7
30.8
187.1
1771.3
1163.5
373.7
45.3
164.1
17.5
28.0
45.5
238. 2
2050.1
1022.6
252.7
29.5
63.6
10.0
11.9
18.1
85.8
926.8
842.5
213.5
28.9
A-3
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APPENDIX B
Stack Test
Packaging A
B
C
D
Dryer E
F
G
H
I
J
K
L
Summary of Size Parameters
Total Mass for Individual
Mass Median
Aerodynamic Diameter,
1.55
1.77
1.56
1.52
1.17
1.11
1.25
1.27
1.21
1.18
1.35
1.18
and
Tests
Respirable
urn Fraction, %
73.0
64.0
69.0
69.0
85.0
92.8
90.0
90.5
91.0
90.0
89.2
92.0
Total Uranium
Collected, mg
0.5588
0.9638
0.6776
0.4980
4.2191
6.5471
4.0741
3.9363
4.9372
3.7717
3.8484
2.2011
B-l
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APPENDIX C
Composite
C.I Packaging Stack
Interval
Lower
Size
DL
0.25
0.32
0.40
0.50
0.64
0.80
1.0
1.28
1.60
2.0
2.5
3.2
4.0
5.0
6.3
8.0
10.0
20.0
In DL
-1.3863
-1.1394
- .9163
- .6931
- .4463
- .2231
0
0.2469
0.470
0.6931
0.9163
1.1632
1.3863
1.6094
1.8405
2.0794
2.3026
2.9957
G(DL)
0.008
0.010
0.025
0.059
0.100
0.158
0.235
0.353
0.492
0.600
0.685
0.730
0.750
0.768
0.780
0.795
0.810
1.000
Size Distribution Data
Aln(D)
0.2469
0.2231
0.2231
0.2469
0.2231
0.2231
0.2469
0.2231
0.2231
0.2231
0.2469
0.2231
0.2231
0.2311
0.2389
0.2231
0.6931
A6(D)
0.002
0.015
0.034
0.041
0.058
0.077
0.118
0.139
0.108
0.085
0.045
0.020
0.018
0.012
0.015
0.015
0.190
AG(D)
Aln(D)
0.00810
0.06722
0.1524
0.1661
0.2599
0.3451
0.4780
0.6229
0.4840
0.3809
0.1823
0.0896
0.0807
0.0519
0.0628
0.0672
0.2741
Interval
Midpoint
D
mp, \im
0.280
0.358
0.447
0.566
0.716
0.894
1.131
1.431
1.789
2.236
2.828
3.578
4.472
5.612
7.099
8.944
14.142
C-l
-------
APPENDIX C
Composite
:.2 Dryer Stack
Interval
Lower
Size
DL
0.25
0.32
0.40
0.50
0.64
0.80
1.0
1.28
1.60
2.0
2.5
3.2
4.0
5.0
6.3
8.3
10.0
13.0
In DL
-1.3863
-1.1394
- .9163
- .6931
- .4463
- .2231
0
0.2469
0.470
0.6931
0.9163
1-1632
1.3863
1.6094
1.8405
2.1163
2.3026
2.5649
G(DL)
0
0
0.01
0.03
0.10
0.20
0-35
0.55
0.725
0.850
0.91
0.95
0.95
0.952
0.955
0.956
0.958
1.0
Size Distribution Data
Aln(D)
0.2469
0.2231
0.2231
0.2469
0.2231
0.2231
0.2469
0.2231
0.2231
0.2231
0.2469
0.2231
0.2231
0.2311
0.2757
0.1863
0.2624
AG(D)
0
0.01
0.02
0.07
0.10
0.15
0.20
0.175
0.125
0.060
0.040
0
0.002
0.003
0.001
0.002
0.042
AG(D)
Aln(D)
0
0 . 0448
0.0896
0.2836
0.4481
Q.6722
0.8102
0 . 7842
0.5602
0.2689
0.1620
0
0.0089
0.0130
0.0036
0.0107
0.1601
Interval
Midpoint
D
mpj ym
0.280
0.358
0.447
0.566
0.716
0.894
1.131
1.431
1.789
2.236
2.828
3.578
4.472
5.612
7.099
9.110
11.402
02
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APPENDIX D
Example of Calculations for Determination of
Particle Concentration and Emission Rate
1. Select Packaging Stack Test A for sample calculation.
2. From Table I and Appendix B:
Stack flow rate =1217 dscfm
Moisture = 0.029 (mol fraction)
Temperature = 91 F
Total mass of UL Oft collected = 0.6589 mg
O O
Respirable fraction = 73%
Sampling rate = 0.507 acfm
Test time = 45 min
3. Calculate the volume of air sampled based on dry conditions,
-------
APPENDIX D (continued)
4. Conversion of Utot to equivalent
6.77 x 105 pCi Ut0t/gm Utot * 0-848 gm Utot/9"1
= 5.74 x 105 pCi Utot/gm
5. Total concentration of Utot °r ^303 in stack:
Total concentration Utot = 378 pCi Utot * 0.6034 dscm
= 627 pCi Utot/dscm
Total concentration UaOg = 627 pCi Utot/dscm * 5-74 x lo5 Pci
Utot/9 U308
= 1.092 mg/dscm
6. Respirable concentration of Utot:
Respirable concentration = 627 pCi Utot/dscm * 0.73
= 458 pci Utot/dscm
7. Total emission rate of Utot:
Total emission rate = 627 pCi Utot/dscm * 1217 dscfm *
1 m3/3531 ft3
= 2.16 x 104 pci Utot/min
= 1.30 x 106 pci/min * yCi/106 pCi
=1.30 yCi Utot/hr
8. Emission rate of respirable Utot:
Respirable emission rate = 0.73 * 1.30 yCi Utot/nr
= 0.95 yCi Utot/hr
D-2
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Particle Size Distribution of Yellowcake Emissions
at the United Nuclear-Churchrock Uranium Mill
5. REPORT DATE
January 1980
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
C.W. Fort, Jr., R. Douglas, R. Gauntt, and
A.R. McFarland
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Radiation Programs-Las Vegas Facility
U.S. Environmental Protection Agency
P.O. Box 18416
Las Vegas, Nevada 89114
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Tests were conducted to characterize the particle size distribution of yellowcake dust
Tom the packaging and dryer stacks of a uranium mill in New Mexico. A multistage iner-
;ial impactor was used to sample the particulate matter to provide a basis for determining
^article size distributions and emission rates. The principal results, from four tests
\nth the packaging stack and eight tests with the dryer stack, are as follows:
Parameter Packaging Stack Dryer Stack
lass median aerodynamic
particle diameter 1.62 ym 1.19 ym
lespirable function
'utot activity associated
vith size _< 2.5 ym)
oncentration of
^ (equivalent
in stack
otal emission rate
f utot (equivalent
69%
558 ± 192 pCi/dscm
(0.97 ± 0.335 mg/dscm)
1.19 ± 0.397 yCi/hr
(2.07 ± 0.692 g/hr)
90%
6120 ± 1070 pCi/dscm
(10.7 ± 1.86 mg/dscm)
62.5 ± 15.8 yCi/hr
(109 ± 27.1 g/hr)
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Particle Size Distribution
Uranium Isotopes
1407
1802
Yellowcake
!. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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