United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-78-185
September 1978
Analysis for Radionuclides
in SRC and Coal
Combustion Samples
nteragency
Energy/Environment
R&D Program Report
-------
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EPA-600/7-78-185
September 1978
Analysis for Radionuclides
in SRC and Coal
Combustion Samples
by
Pamela A. Koester and Warren H. Zieger
Hittman Associates, Inc.
9190 Red Branch Road
Columbia, Maryland 21045
Contract No. 68-02-2162
Program Element No. EHE623A
EPA Project Officer: William J. Rhodes
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
-------
TABLE OF CONTENTS
Page
1. SUMMARY 1
2. INTRODUCTION 3
3. SAMPLE COLLECTION AND ANALYSIS 6
4. DATA ANALYSIS 10
5. ESTIMATED RADIONUCLIDE EXPOSURE LEVELS 24
REFERENCES 27
iii
-------
1. SUMMARY
This report deals with the determination of the levels
of uranium, thorium, and their daughter products in coal,
SRC, coal flyash, and SRC flyash samples taken from Georgia
Power Company's Plant Mitchell during the May and June 1977
combustion tests to compare the environmental emissions from
the use of coal and SRC in the boilers. Gross alpha and
beta activities were also measured in the samples.
Uranium and thorium were observed to be present at
concentrations ranging from 0.8 to 39 ppm and 3.7 to 20 ppm,
respectively. Calculated levels of other radionuclides in
secular equilibrium with uranium and thorium were found to
range from 7.4x10" ppm to 1.0x10 ppm. Quantitative
alpha measurements could not be made due to the self absorp-
tion of the alpha particles in the samples. Beta measure-
ments, however, could be taken and were found to be on the
12
order of 50 pCi/gm. (A pCi is 10 curies. A curie is a
basic unit for measurement of radioactivity, equaling
3.7x10 nuclear transformations per second).
Levels of radionuclides in the samples were also com-
pared with reported levels of uranium and thorium in coal
and SRC and with estimated emissions from coal fired power
plants. Uranium and thorium levels in the samples were
found to be of the same order of magnitude as those reported
in the literature. Data obtained from Plant Mitchell and
other coal fired power plants, as well as data obtained in
-------
this report, were used to estimate the level of uranium-238
which may be discharged from a power plant. The estimated
3
level was found to be 0.2 yg/m which is lower than allowed
3
general public dose radiation levels of 7.0 ug/m . This
leads one to conclude that the radionuclide levels present
in the tested samples do not appear to pose any significant
problem from a radiotoxic standpoint. Further analysis of
various types of coal and SRC products is recommended,
however, before this may be concluded on an overall basis.
-------
2. INTRODUCTION
There are three major distinct chains of radioactive
elements contained in essentially all coals: (1) the uranium
series which originates with uranium-238; (2) the thorium
series which originates with thorium-232; and (3) the
actinium series which originates with uranium-235. These
three elements decay into a number of radioactive species
which are important from a radiotoxic standpoint. The decay
process is a process of transformation of radioactive ele-
ments to other elements. This transformation is acompanied
by emisson of alpha or beta particles and gamma radiation.
When a radioactive element decays, a new radioactive element
is born which itself is subject to decay. The uranium,
thorium and actinium decay series are shown in Figure 1.
Since the first member of each decay series has a relatively
long half-life when compared to the other members, a steady-
state condition is established which is known as "secular"
equilibrium. This steady-state condition allows one to
calculate the concentration of each of the daughter radio-
nuclides. Those elements of most importance include thorium-
230, radium-226, radon-222, lead-210, polonium-210, radium-
228, thorium-228, and radon-220.
The concentrations of elements within these decay
chains may vary significantly from one coal to the next. It
has been observed that eastern coals generally contain about
1.6 ppm uranium and 2.0 ppm thorium although individual
values may vary considerably (2). Western coals have been
-------
DO
'
C
-
-
-
u
~
I
144 -— ^-t-
78 80 82 84 86 88 90 92 94
Hg Tl Pb Bi Po Ai Rn Fr Ka Ac Th Ha U
Atomic Number
78 80 82 84 86 88 90 92 94
Hg Tl Pb Bi Po At Rn Fr Ra Ac 1h Pa U
Atomic Number
78 80 82 84 86 88 90 92 94
Hg Tl Pb Bi Po Ai Rn Fr Ra Ac Th Pa U
Atomic Number
Figure 1. Radioactive Decay Chains (1)
-------
reported to contain much higher concentrations ranging from
10 to greater than 5000 ppm (3). The concentrations of
uranium-238, uranium-235 and thorium-232 naturally affect
the levels of other radionuclides within the three chains as
they are all considered to be in secular equilibrium with
each element within their respective chains.
It has been observed in coal and SRC processing opera-
tions that radionuclides are most likely to be found in
solid residues and flyash (4). Smaller quantities may be
found in gaseous and liquid wastes. These operations tend
to concentrate the radionuclides thereby possibly posing
some occupational health hazards. This report examines the
levels of several radionuclides in various coal and coal
product samples and the significance of these levels from a
radiotoxic standpoint. Also, the measurement of numerous
radionuclides in the SRC samples is especially significant
in view of the fact that the SRC samples were obtained from
the first commercial coal fired facility ever to use SRC
in a full scale comprehensive combustion test program.
-------
3. SAMPLE COLLECTION AND ANALYSIS
3.1 Sample Collection
Samples were collected from combustion tests performed
at Georgia Power Company's Plant Mitchell during the summer
of 1977 (5). At this installation, both Kentucky coal and
SRC solid fuel were individually burned in a pulverized
coal-fired boiler to determine if SRC could replace coal as
a primary fuel.
A Source Assessment Sampling System (SASS) train
analysis was performed on the stack gases from the boilers.
A typical train is shown in Figure 2. Samples analyzed for
radionuclides in this report were taken from the 10-micron,
3-micron, and 1-micron cyclones, and from the filters of
coal Run No. 1 on 5/25/77 and SRC Run No. 2 on 6/17/77. Two
sets of coal, SRC solid fuel, coal particulate, and SRC
particulate samples were analyzed.
3.2 Sample Preparation
In order to prepare the coal and SRC solid fuel samples
for analysis, it was first necessary to pulverize and ash
them to remove all available carbon. This step facilitated
the subsequent sample digestion process. Coal and SRC
particulate samples were also ashed and digested prior to
analysis after a specific homogeneous mixture of particulate
-------
STACK T.C.
HEATER
CON-
TROLLER
CONVECTION
OVEN
r~
FILTER ,
/^x-1 SS PROBE* | |-
1
1
1
JIJ
GAS
COOLER
DRY GAS METER ORIFICE METER
CENTRALIZED TEMPERATURE
AND PRESSURE READOUT
CONTROL MODULE
GAS
TEMPERATURE
T.C.
XAD-2
CARTRIDGE
IMP/COOLER
TRACE ELEMENT
COLLECTOR
CONDENSATE
COLLECTOR
10 CFM
VACUUM PUMP
IMPINGER
T.C.
Figure 2. Source Assessment Sampling System (5)
-------
matter had been obtained. The weights of cyclone and filter
particulates used in the analysis are given in Table 1 along
with the coal and SRC sample weights.
The samples used to determine gross alpha and beta
activities were only pulverized prior to analysis. The
weight percentage of cyclone and filter particulate matter
was similar to that shown in Table 1.
3.3 Sample Analysis
Levels of uranium, thorium, and gross alpha and beta
activities were measured in all coal, SRC solid fuel, coal
particulate and SRC particulate samples. Levels of uranium
were measured using techniques based on the U.S. Geological
Survey Fluorimetric Methods of Uranium Analysis (15). Melts
obtained by fusing uranium salts with sodium fluoride fluor-
esce a brilliant yellow green when exposed to ultraviolet
light. The intensity of the fluoresence is proportional,
within wide limits, to the amount of uranium present, and
this relationship is the basis for the quantitative fluori-
metric determination of uranium. A standard colorimetric
test - ASTM D2333-68, was used to determine the levels of
thorium in the selected samples (6). Alpha and beta activ-
ities were measured using a Baird Atomic Model 530 Spectro-
meter with a 2-inch gas flow proportional detector having an
ultra-thin window ( 100 mg/cm3). In order to detect the
presence of any uranium and thorium daughter products, gamma
ray activities were measured using a Baird Atomic Model 530
Spectrometer with a 1.75 inch x 2 inch thick Nal (TI) scin-
tillation detector.
8
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TABLE 1. WEIGHT DISTRIBUTION OF SAMPLES ANALYZED
(Grams)
Composite 10- Cyclone
Coal
Particulates
#1 0.03750
n 0.037385
SRC
Particulates
#1 0.5719
//2 0.5719
Coal
#1
#2
SRC
//I
#2
3- Cyclone 1- Cyclone Filters Total
0.29040 0.28090 0.05540 0.6641
0.29020 0.28100 0.05550 0.664085
0.1902 0.0106 0.2312 1.0039
0.1901 0.0103 0.2294 1.0017
2.0036
2.0051
2.0041
2.0115
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4. DATA ANALYSIS
4.1 Analyses by Fluorimetric Methods
4.1.1 Summary of Analyses
Table 2 lists the results of the uranium and
thorium analyses. From these values, the concentrations of
their daughter products were calculated assuming they are in
secular equilibrium with their respective parent, and mea-
sured uranium is 99.27 percent uranium-238 (natural uranium
contains this percentage of uranium-238). Calculated con-
centrations of uranium, thorium, and their daughter products
of particular interest from a radiotoxic standpoint and/or
with long half-lives are given in Table 3.
4.1.2 Discussion of Data
Several observations may be made based on the
results of the laboratory analyses:
(1) Uranium levels were found to be less than
thorium in all cases but the SRC parti-
culates.
(2) Uranium and thorium were more concentrated in
the SASS train particulate samples than in
the coal and SRC solid fuel.
(3) The limited data do not allow one to predict
any trends in the increase of uranium, thorium,
and their daughter products in the particulate
10
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TABLE 2. RADIONUCLIDE CONCENTRATIONS
(ppm by weight)
Source
Coal
Sample #1
Sample #2
SRC
Sample #1
Sample #2
Coal Particulates
Sample #1
Sample #2
SRC Particulates
Sample #1
Sample #2
Uranium
1.3
1.4
0.8
1.3
2.6
1.9
39
28
Thorium
4.74
4.24
4.99
3.73
14.99
20.50
11.46
9.48
11
-------
to
TABLE 3. CALCULATED LEVELS OF RADIONUCLIDES IN COAL AND COAL PRODUCTS
(ppm by weight)
Product/Source
u238
Th234
u234
Th230
Ra226
Rn222
Bi210
Po210
Th232
Ra228
Th228
Ra224
„ 220
Rn
235
u
Th231
pa239-231
A 227
Ac
227
Til
_, 223
Ra
Pb211
Coal
1.29-1.39
1.9-2.04xlO~11
7. 0-7. 54x1 0~5
2.1-2.3xlO~5
4.4-4.7xlO~7
2.8-3.0xlO~12
3.4-3.7xlO~12
9.6-10.3xlO~U
4.24-4.74
1.73-1.94xlO~9
0.57-.64xlO~9
2.8-3.2xlO~12
5-5.7xlO~16
0.009-0.01
3.7-4.0xlO~13
4.2-4.5xlO~6
2.6-2.8xlO~9
6.1-6.5xlO~12
3.7-4.0xlO~12
1.14-1.23xlO~16
SRC
0.79-1.29
1.16-1.25xlO~n
4. 3-4. 6x1 0~5
1.3-1. 4x1 0~5
2.7-2.9xlO~7
1.7-1.85xlO~12
2.3-2.44xlO~12
5.9-6.4xlO~U
3.73-4.99
1.7-2.99xlO"9
0.56-0.75xlO~9
2.8-3.8xlO~12
5-6.8xlO~16
0.006-0.009
2.3-3.7xlO~13
2. 6-4. 2x1 0~6
1.6-2. 6x1 0~9
3.8-6.1xlO~12
2.4-3.7xlO~12
0.74-1.14xlO~16
Coal Particulate
1.88-2.58
2.77-3.8xlO~U
10.2-14xlO~5
3. 0-4. 2x1 0~5
6.4-8.8xlO~7
4.1-5.6xlO~12
5.4-7.4xlO"12
19.2-14.0xlO~U
14.99-20.5
6.9-9.3xlO~9
2.3-3.0xlO~9
11.5-15xlO"12
20.7-27xlO~16
0.014-0.02
5.4-7.7xlO"13
6.1-8.8xlO"6
3.8-5.5xlO~9
8.9-12.8xlO~12
5. 5-8. Oxl O"12
1.7-2.5xlO~16
SRC Particulate
27.8-38.7
4.10-5.72xlO~U
15-21xlO~5
4.5-6.3xlO~5
9.5-13.3xlO~7
6.0-8.4xlO~12
8.0-ll.lxlO~12
20.6-28.9xlO~U
9.48-11.46
4.4-5.3xlO~9
1.4-1.7xlO~9
7-8.5xlO~12
12.6-15.3xlO~16
0.20-0.30
77-lllxlO~13
87-126xlO~6
54-79xlO~9
126-185xlO~12
78-115xlO~12
24-35xlO"16
-------
samples, whether the radionuclides are more heav-
ily concentrated in SRC flyash as opposed to coal
flyash, or what percentage of the radionuclides
pass from coal to SRC since the coal is not known
to be the same coal from which the SRC was pro-
duced. Literature has indicated, however, that at
least 90 percent of the uranium is expected to be
retained in the bottom ash and collected flyash
(4).
4.1.3 Variation Within Data
Uranium levels were measured in duplicate samples
by uranium fluorimetric analysis to determine whether the
fluctuation between pairs of results was real or due to
inadequacies in the method. The variance and standard
deviation of the paired results were found to be 1.37 per-
cent and 1.22 percent, respectively. This leads one to
conclude that the differences in the reported values are not
due to laboratory procedures but rather to nonhomogeneous
samples. This is expected to be similar for the thorium
results.
Efforts were also made to compare the observed
levels of uranium and thorium in coal and SRC samples with
those reported in the literature. Figures 3 and 4 give some
indication of the wide range of uranium and thorium levels
which may be found in coal. The data from the Eastern
United States are plotted as unpatterned bars, those from
the Illinois Basin as vertically striped bars, and those
from the Western United States as horizontally striped bars.
Table 4 provides reported data collected on levels of uran-
ium and thorium in different types of samples.
13
-------
a ••
i-
0.0 2.0
1.0 10.0
21
2 '•
IS
0.0 1.
S i
6 I
(PPM)
u IPPM
Figure 3. Distribution of Thorium
in coals analyzed (7)
Figure A. Distribution of Uranium
in coals analyzed (7)
Note: Unpatterned bars - Eastern United States
Vertical striped bars - Illinois basin
Horizontal striped bars - Western United States
-------
TABLE 4. LEVELS OF URANIUM AND THORIUM IN COAL AND RELATED PRODUCTS
(ppm by weight)
Coal Boiler Precipitator Mineral
Location Coal Flyash Residue Collected Ash SRC Residue
Uranium
Navajo Mines (4)c 2.56
Rocky Mt. Area (4)c 0.69 -- 6.78 9.4
S. Illinois (4)c 2.18 -- 14.9 30.1
Four Corners,NM (4)° -- -- 9.77 9.8
Illinois (8)c 1.1-4.2
General (9)b 1.41-1.53 11.6-11.9
Kentucky <10)a 1.1 — — -- 0.54 .73
Thorium
Kentucky (10)c 1.9
Illinois (8)c 3.1-8.0
General (9)b 3.0-6.5 26.1-30.4 — — 0.19 10.0
aNeutron Activation Analysis
Delayed Neutron Determination
X-ray Fluorescence
-------
The coal samples analyzed in this project origi-
nated from Kentucky while the SRC samples originated from
the processing of Illinois coal. Average levels of uranium
and thorium reported in the literature for Illinois coals
are 1.5 and 2.1 ppm, respectively (7). Average levels of
uranium and thorium reported for Kentucky coals are 1.85 and
2.6, respectively (7). The reported levels of these radio-
nuclides are not significantly different between the two
types of coal.
If we assume the coal samples contain approxi-
mately 10 percent ash and allow the variable "X" to repre-
sent the quantity of coal processed (in gm/day), then the
quantities of uranium and thorium observed in the analyzed
samples may be summarized as shown in Table 5.
TABLE 5. LEVELS OF URANIUM AND THORIUM IN COAL SAMPLES
(Ug/day)'
Sample Uranium Thorium
Coal Sample 1 1.3X 4.7AX
Coal Sample 2 1.4X 4.24X
Coal Sample 1 Particulates 0.03X 1.50X
Coal Sample 2 Particulates 0.02X 2.05X
16
-------
For all samples, the quantities of uranium and
thorium in the particulate samples were found to be lower
than in the coal samples. This observation correlates well
with the literature where it has been suggested that uranium
and thorium are partitioned between the flyash, bottom ash,
liquid streams, and, in the case of coal liquefaction
processes, in the final SRC product.
If we assume the SRC to contain, on the average,
0.1 percent ash and allow the variable "Y" to represent the
quantity of SRC combusted (in gin/day) , then the quantities
of uranium and thorium observed in the analyzed samples (in
micrograms/day) may be summarized as shown in Table 6.
TABLE 6. LEVELS OF URANIUM AND THORIUM IN SRC SAMPLES
Sample
SRC Sample
SRC Sample
SRC Sample
SRC Sample
(ug/day)
Uranium
1 0.8Y
2 1.3Y
1 Particulate 0.04Y
2 Particulate 0.03Y
Thorium
4.99Y
3.73Y
0.01Y
0.009Y
In all instances, the total quantity of uranium
and thorium present in the particulate samples appears to be
significantly less than the levels observed in the SRC
samples. This leads one to conclude that the uranium and
thorium is being partitioned more heavily into other process
constituents.
17
-------
Although this analysis appears to indicate that
the total quantities of uranium and thorium are smaller in
the flyash samples, the variable and limited data do not
allow one to conclude that this is the general trend which
should be observed in all cases. This is especially evident
in view of the fact that bottom ash samples could not be
analyzed to substantiate reported literature observations
that 90 percent of the uranium and thorium should be re-
tained in the bottom and flyash (A).
Assuming the following data for the combustion of
SRC Run No. 2 on June 17, 1978 (data collected during plant
visit).
Fuel Flow - 8.060 kg SRC/hr.
SASS Sample Volume - 28.5 m3
Gas Flow - 3,620 m3/minute
Weight of SRC particulates per sample volume -
1.0017 gm
Uranium concentrations in:
SRC - 1.3 ppm
SRC particulates - 28 ppm
Thorium concentrations in:
SRC - 3.7 ppm
SRC particulates - 9.5 ppm
18
-------
Weight of SRC = 362° S x £0_jnin x 1 Sample x 1.0017 8tn
Particulates/Hr min hr 28.5 m 1 sample
= 7634 gtn/hr
Weight of Uranium = 7634 ^ x ^ =0.214 gm/hr
in particulates hr 1,000,000
Weight of Uranium = 8,060,000 gm x 1_3 = 1Q 48
in SRC feed hr 1,000,000
% Uranium not = 1Q'48 " °-2U x 100 = 98
in Particulates 10.48
As shown above, the percentage of uranium not in
the particulates was calculated to be approximately 98 per-
cent of the total uranium in the SRC feed. Similar calcu-
lations for thorium show greater than 99 percent of total
thorium not in the particulates. It is unfortunate that no
samples were taken during the Plant Mitchell runs of the
bottom ash. Therefore, there is no way to verify or re-
fute this indicated bottom ash radioactivity concentration.
Table 7 lists the observed sample means (x) and
the means of the literature values (y). On an absolute
basis, the observed sample means correlate well with the
means of the literature values and are of the same general
order of magnitude.
4.2 Uranium Analysis by Atomic Absorption
Efforts to measure the levels of uranium in the samples
were unsuccessful. Limits of detectability for uranium were
found to be on the order of 50 ppm.
19
-------
TABLE 7. EVALUATION OF SAMPLE DATA
(ppm by weight)
Source
Coal
Uranium
Thorium
SRC
Uranium
Thorium
Coal Particulates
Uranium
Thorium
SRC Particulates
Uranium
Thorium
Observed
Data (x)
1.4
4.5
1.0
4.4
2.2
17.8
33.5
10.5
Literature
Data
1.0 (7)
2.0 (7)
0.5 (10)
0.2 (10)
11.8 (9)
28.0 (9)
7.0 (10)
10.0 (10)
20
-------
4.3 Gross Alpha and Beta Activities
4.3.1
Summary of Analyses
Alpha and beta activities were measured in all the
samples listed in Table 1. Radiation was qualitatively
detected in all samples, but only quantitatively measured
for the coal and SRC solid fuel particulate samples. Alpha
radiation could not be determined due to self absorption of
the alpha particles in the samples. Results of the beta
analysis in coal and SRC particulate samples are given in
Table 8. Expected levels of selected radionuclides are
given in Table 9.
TABLE 8. BETA ACTIVITIES OF COAL AND SRC SAMPLES
Source
Coal
Coal Flyash
SRC
SRC Flyash
Weight
(gtn)
1.945
0.678
1.842
0.208
Activity
(pCi)
BD
17.2
BD
12.3
Activity
Concentration
(pCi/gm)
BD
25.0
BD
59.0
BD = Below Detection
4.3.2
Discussion of Data
Photo-peak analysis was used in an attempt to
confirm and identify the presence of uranium and thorium
daughter products. The 239 KeV gamma ray of lead-212 (thor-
ium- 232 daughter) and the 609 KeV gamma ray of bismuth-214
(uranium-238 daughter) were selected because of their high
21
-------
TABLE 9. EXPECTED RADIONUCLIDE ACTIVITIES
(pCi/gm)
Product /Source
u238
Th23A
u23A
Th230
Ra226
Rn222
Bi21°
Po210
232
Tli
„ 228
Ra
„ 224
Ra
Rn22°
u235
Th231
Pa231
Ac227
Th227
Ra223
Pb211
Coal
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004-0.005
0.004-0.005
0.004-0.005
0.004-0.005
0.002
0.002
0.002
0.002
0.002
0.002
0.002
SRC
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.004-0.005
0.004-0.005
0.004-0.005
0.004-0.005
0.001-0.002
0.001-0.002
0.001-0.002
0.001-0.002
0.001-0.002
0.001-0.002
0.001-0.002
Coal
Particulates
0.006-0.008
0.006-0.008
0.006-0.008
0.006-0.008
0.006-0.008
0.006-0.008
0.006-0.008
0.006-0.008
0.017-0.023
0.017-0.023
0.017-0.023
0.017-0.023
0.003-0.004
0.003-0.004
0.003-0.004
0.003-0.004
0.003-0.004
0.003-0.004
0.003-0.004
SRC
Particulates
0.008-0.012
0.008-0.012
0.008-0.012
0.008-0.012
0.008-0.012
0.008-0.012
0.008-0.012
0.008-0.012
0.011-0.013
0.011-0.013
0.011-0.013
0.011-0.013
0.04 -0.06
0.04 -0.06
0.04 -0.06
0.04 -0.06
0.04- 0.06
0.04 -0.06
0.04 -0.06
22
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yields. The spectrometer was set up to window in on these
energies. Concentrations of these elements were too low to
measure using this method. The low levels of radionuclides
observed in these samples correlate with the calculated
levels listed in Tables 3 and 4.
The summations of calculated beta radiation levels
resulting from the presence of uranium, thorium, and their
daughter products were found to be much lower than those
recorded by the spectrometer. Possible explanations for
this observation include: incorrect counting efficiency,
interference from radionuclides other than those of specific
interest, and levels of radiation being at the threshold of
detection limits as was the case for the atomic absorption
unit.
23
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5. ESTIMATED RADIONUCLIDE EXPOSURE LEVELS
The levels of observed and calculated radiation appear
to be quite small. To give some indication of their small-
ness, they may be compared to typical occupational and
general public exposure levels given in Table 10 (3) . The
following assumptions, based on data obtained from Plant
Mitchell and other typical coal fired power plants, were
used to estimate the levels of uranium-238 expected to be
discharged from a power plant which combusts SRC solid fuel.
(1) Stack gas particulates _ R A9 ,n-3
coal input °'^ x iu
(2) Ash content of coal - 15.01% (11)
(3) Expected ash content of SRC = 0.173 (12)
(4) Stack gas particulates _ 0.1 ft ~3
SRC input 15.01 B
(5) Stack gas _ Stack gas
coal input SRC input
= 183 scf/lb coal or SRC (avg) (13)
(6) SRC load = 17,600 Ib/hr (Plant Mitchell tests) (14)
(7) U238 = 0.9927 (U)
24
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TABLE 10 EXCERPTS FROM 10CFR20 STANDARDS FOR PROTECTION AGAINST RADIATION
FOR MAJOR RADIONUCLIDES ASSOCIATED WITH COAL-BURNING FACILITIES
Element
(Isotope)
"Occupational"
Exposure Standard
Air Water
"General Public"
Exposure Standard
Air Water
"Occupational"
Exposure Standard
Air Water
yg/m^ umg/fc
"General Public"
Exposure Standard
Air Water
yg/m3 pmg/Jl
Uranium Series
Uranium (238) S
I
Thorium (234)
Uranium (234)
Thorium (230)
Radium (226)
Radon (222)
Lead (210)
Bismuth (210)
1,2
1,1
S
T
S
I
S
I
S
T
s3
S
T
S
T
Polonium (210) S
I
-7 x 10-11
1 x 10-10
6 x 10~8
3 x 10~8
6 x 10-10
1 x 10-10
2 x 10-12
1 x 10-11
3 x 10-U
5 x ID'11
3 x 10'8
1 x ID'10
2 x 10-10
6 x 10"9
6 x 10~9
5 x 10-10
2 x 10~L0
1 x 10~3
1 x 10~3
5 x 10-11
5 x 10~4
9 x 10"4
9 x 10~4
5 x 10"5
-4
9 x 10
4 x 10~7
9 x 10~4
4 x 10'6
5 x 10~3
1 x 10~3
1 x 10"3
2 x 10~5
8 x 10~4
3 x 10-12
5 x ID'12
2 x 10~9
1 x 10~9
2 x 10-11
4 x 10~12
8 x 10-14
3 x 10-13
3 x 10-12
2 x 1C'12
3 x 10~9
4 x 10~12
8 x 10-12
2 x 10-10
2 x 10-10
2 x 10-11
7 x 10-12
4 x 10~5
4 x 10"5
2 x 10"5
2 x 10"5
3 x 10"5
3 x 10~5
2 x 10'6
3 x 10~5
3 x 10'8
3 x 10~5
1 x 10~7
2 x 10~4
4 x 10"5
4 x 10~5
7 x 10~?
3 x 10~5
200
300
2.6 x 10~6
1.3 x 10~6
9.7 x 10~2
1.6 x 10"2
1 x 10~4
5 x 10"4
3 x 10~5
5 x 10~5
1.9 x 10~7
1.2 x 10~6
2.4 x 10~6
9
9
1.1 x 10~?
4.4 x 10"8
2.
2.
1.
1.
2.
4.
3 x 103
3 x 103
2 x 10~8
2 x 10~8
5 x 10
5 x 10'1
6 x 10~3
6 x 10~2
4 x 10~7
9 x 10~4
4.8 x 10"8
6.0 x 10~5
4
1
1.3
1.3
.4 x 10~9
.8 x 10~7
8.
4.
3.
6.
4.
1.
7
15
6 x 10~8
3 x 10"8
•j
2 x 10
5 x 10~4
1 x 10"6
5 x 10~5
£
3 x lO'6
2 x 10'6
Q
1.9 x 10 "
4.8 x 10~8
9.6 x 10~8
4
1
0.3
0.3
.4 x 10~
.5 x 10~9
1.2 x 10
1.2 x 10
8.6 x 10~10
8.6 x 10~10
3
4.8 x 10
4.8 x 10~3
A
1 x 10
1.5 x 10"3
_ 0
3 x 10 8
1 x 10~5
1.2 x 10~9
2.3 x 10~6
_9
6.1 x 10
, -2
6.1 x 10
_i n
1.6 x 10 1U
6.8 x 10~9
-------
(8) U = 33.5 ug/gm particulate SRC (data from this
report)
U238 discharged = (5.6xlO"5)(1.76xl04)(33.5)(454)(0.9927)
(183)(1.76xl()4)(0.028)
U238 =0.2 yg/m3
This compares to the general standard of 7.0 yg/m and
O
is much less than an occupational exposure of 200 yg/m shown
in Table 10 for uranium-238. Since this analysis has not
included dispersion in the atmosphere, the actual levels
which should be observed would be significantly less than
2
0.2 yg/m . The conclusion that the levels of uranium,
thorium, and their daughter products which may be discharged
are quite small has also been reported by other authors (3).
This may not be the case, however, for coals with very high
uranium and thorium contents.
26
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REFERENCES
1. Arya, A.P., Fundamentals of Nuclear Physics, Boston
1966.
2. Gluskoter, H.J., W.G. Miller, R.A. Cahel, R.R. Ruch,
and M.F. Shimp, "An Investigation of Trace Elements in
Coal," Illinois State Geological Survey, Urbana,
Illinois. EPA-600/7-77-064, June 1977.
3. Battelle, Columbus Laboratories. Radionuclides from
FBC Processes - Brief Technical Memo No. 3_, January
1977.
4. Los Alamos Scientific Laboratory. A Review of Trace
Element Studies Related to_ Coal Combustion in The Four
Corners Area of New Mexico. Los Alamos, New Mexico,
July 1976.
5. Koralek, C.S. and May, V.B., "Flue Gas Sampling During
the Combustion of Solvent Refined Coal in a Utility
Boiler," In: Proceedings of EPA Symposium on Environmental
Aspects of Fuel Conversion Technology, III, September
1977, Hollywood, Florida, EPA-600/7-78-063, Franklin
Ayer, Compiler.
6. ASTM. 1976. Annual Book of ASTM Standards Part 31^
Water, ASTM 1976.
27
-------
7. Illinois State Geological Survey. EPA-600/7-77-064.
Trace Elements in Coal: Occurrence and Distribution.
June 1977.
8. Los Alamos Scientific Laboratory. Trace Elements
Characteriz at ion and Remoya1/Reco very from Coal and
Coal Wastes, Los Alamos, New Mexico, October 1977.
9. EPA-NBS Interlaboratory Comparison for Chemical
Elements in Coal, Flyash, Fuel Oil and Gasoline, May
1973.
10. Fruchter, J.S., J.C. Laul, M.R. Peterson, P.W. Ryan,
and M.E. Turner. High Precision Trace Element and
Organic Constituent Analysis of_ Oil Shale and Solvent-
Refined Coal Materials. December 19, 1977.
11. Federal Power Commission. January 1976. Steam-Electric
Plant Air and Water Quality Control Data. Washington,
D.C.
12. Pittsburgh and Midway Coal Mining Co. Solvent Refined
Coal Pilot Plant.
13. Radian Corp., September 1975. Coal Fired Power Plant
Trace Element Study. Prepared for the EPA, Region VIII,
Denver, Colorado.
14. Data obtained from the Plant Operator at Georgia Power
Company's Plant Mitchell.
15. U.S. Department of the Interior. U.S. Geological
Survey Fluorimetric Methods of Uranium Analysis. Geo-
logical Survey Circular 199.
28
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
. REPORT NO.
EPA-600/7-78-185
2.
3. RECIPIENT'S ACCESSION NO.
4. T.TUE AND SUBTITLE Analysis for Radionuclides in SRC and
oal Combustion Samples
5. REPORT DATE
September 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
Pamela A. Koester and Warren H. Zieger
8. PERFORMING ORGANIZATION REPORT NO.
. PERFORMING ORGANIZATION NAME AND ADDRESS
littman Associates, Inc.
9190 Red Branch Road
olumbia, Maryland 21045
10. PROGRAM ELEMENT NO.
EHE623A
11. CONTRACT/GRANT NO.
68-02-2162
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PE
Final; 11/77 - 7/78
PERIOD COVERED
14. SPONSORING AGENCY CODE
EPA/600/13
IB.SUPPLEMENTARY NOTES ffiRL-RTP project officer is William J. Rhodes, Mail Drop 61, 919/i
U41-2851.
16.ABSTRACTThe report deals with the determination of the levels of uranium, thorium,
and their daughter products in coal, Solvent Refined Coal (SRC), coal flyash, and SRC
lyash samples from Georgia Power Co. Ts Plant Mitchell May and June 1977 combus-
ion tests to compare the environmental emissions from the use of coal and SRC in the
)oilers. Gross alpha and beta activities were also measured. Uranium and thorium
concentrations ranged from 0.8 to 39 ppm and 3. 7 to 20 ppm, respectively. Calculated
evels of other radionuclides in secular equilibrium with uranium and thorium ranged
rom 7.4 x 10 to the minus 17th power to 0.0001 ppm. Alpha levels could not be quanti-
ied due to the self absorption of the alpha particles. Beta levels, however, were on
he order of 50 pCi/g. (A pCi is 10 to the minus 12th power curies; a curie is a basic
inlt for measurement of radioactivity, equalling 3.7 x 10 to the 16th power nuclear
ransformations per second.) Levels of radionuclides were also compared with repor-
ed levels of uranium and thorium in coal and SRC and with estimated emissions from
joal-fired power plants. Uranium and thorium levels were of the same order of magni-
ude as those reported in the literature. Data from Plant Mitchell and other coal-fired
jower plants, as well as data obtained in this report, were used to estimate the level
>f uranium-238 that may be discharged from a power plant: the estimated level was
).2 micrograms/cu m. wfilch'is below the allowable public use level. .
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
oal
iquefaction
ombustion
hdustrial Processes
Radioactive Isotopes
Analysis
Uranium
Thorium
Fly Ash
Alpha Particles
Beta Particles
Pollution Control
Stationary Sources
Solvent Refined Coal
Radionuclides
13B
21D
07D
21B
13H
18B
MB_
07B
20H
8. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
33
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
29
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