United States
Environmental Protection
Agency
Environmental Vo~>'. :-'•••'
Laboratory
Cincinnati OH 45268
Research and Development
Analysis
of Radioactive Contaminants
in By-Products
From Coal-Fired
Power Plant Operations
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL MONITORING series.
This series describes research conducted to develop new or improved methods
and instrumentation for the identification and quantification of environmental
pollutants at the lowest conceivably significant concentrations. It also includes
studies to determine the ambient concentrations of pollutants in the environment
and/or the variance of pollutants as a function of time or meteorological factors.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/4-78-039
July 1978
ANALYSIS OF RADIOACTIVE CONTAMINANTS IN BY-PRODUCTS
FROM COAL-FIRED POWER PLANT OPERATIONS
by
Herman Krieger and Betty Jacobs
Environmental Monitoring and Support Laboratory
U. S. Environmental Protection Agency
Cincinnati, Ohio 45268
ENVIRONMENTAL MONITORING AND SUPPORT LABORATORY
-OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
This report has been reviewed by the Environmental Monitoring and
Support Laboratory, U. S. Environmental Protection Agency, and approved for
publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
ii
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FOREWORD
Man and his environment must be protected from the adverse effects of
pesticides, radiation, noise, and other forms of pollution, and the unwise
management of solid waste. Efforts to protect the environment require a
focus that recognizes the interplay between the components of our physical
environment—air, water and land. The Environmental Monitoring and Support
Laboratory contributes to the multidisciplinary focus through progress
engaged in:
•Studies on the effects of environmental contaminants on the bio-
sphere, and
•A search for ways to prevent contaminaton and to recycle valuable
resources.
This report focuses on the radioactive contaminants released to the
environment in the course of fossil fuel power plant operations and
ascertains whether it has a deleterious effect on the population.
Dwight G. Ballinger
Director
Environmental Monitoring and
Support Laboratory
iii
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ABSTRACT
Electrical power requirements for the next 200 years will necessitate
a doubling of our present generating capacity. Even with the imposition of
strong conservation measures, additional facilities and sources of fuel must
become available. Because of restrictions on construction of nuclear
installations, coal-fired power plants have to assume most of this burden.
Since environmental discharges associated with the coal power industry
contain not only the oxides of sulfur and nitrogen, but also significant
concentrations of natural radioactivity, a potential radiation hazard from
radium, thorium and uranium could result as more coal is burned.
In this study, the major radionuclides detected in fossil fuel power
plant operations have been identified and quantified. Samples of coal, fly
ash, bottom ash and scrubber sludge were collected from different regions in
the U.S. and analyzed for radium, thorium and uranium. The standard
radiochemical procedures were modified in order to obtain reoroducible
results for the variety of samples analyzed, which then can be used to
calculate a radioactivity balance on the basis of normal operations.
The report tabulates the spectrum of activity levels in a variety of
samples, and compares the results from non-destructive spectrometry and from
radiochemical separations. The environmental impact of an expanding
fossil-fuel power plant operation is discussed, and it is concluded that for
the present, no radiation hazard exists.
This report covers a period from January 1976 to December 1977 and
work was completed as of February 1978.
iv
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CONTENTS
Foreword iii
Abstract iv
Figures vi
Tables vi
Acknowledgment vii
1. Introduction 1
2. Experimental 5
3. Results ' 7
References 16
Appendix 18
I. Pretreatment of Samples 18
II. Radiochemical Analytical Procedures 18
A. Radium-226 Analysis 18
B. Uranium and Thorium Analysis 27
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FIGURES
Number Page
1 Growth of Population and Energy Consumption from 1900 to
Present and Predictions to 2000 2
2 Schematic of Coal Burning Plant Depicting Sampling Ports . . 4
3 Ge(Li) Spectra Comparing Instrument Background, Kentucky
Coal, and Electrostatic Precipitated Fly Ash 8
4 Radon Emanation Apparatus with Scintillation Cell 20
5 A Typical Radon Bubbler (Emanation tube) 21
6 The Growth of Radon-222 from Radium-226 22
7 A Typical Scintillation Cell for Radon Counting 24
TABLES
Number Page
1 Comparison of Non-Destructive and Radiochemical '
Analysis of 226Ra 10
2 Radiochemical Analysis of Coal and Coal By-Products,
pCi/g 11
3 By-Product Production and 22^Ra Activity Data for
a 1000 Megawatt Fossil Fuel Plant 13
vi
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ACKNOWLEDGMENT
The cooperation of the Cincinnati Gas and Electric Company and of the
Radiation Control Branch, Bureau of Health Services, Frankfort, Kentucky, is
gratefully acknowledged. Their engineers and technicians were most helpful
in obtaining and delivering the representative samples required.
The thorium and uranium analyses were performed by the analytical
section under Mrs. Ann Strong, EERL, Montgomery, Alabama, and the dose
determinations were computed and interpreted by Dr. R. L. Blanchard, EERL,
Montgomery, Alabama. This assistance is deeply appreciated.
vii
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SECTION 1
INTRODUCTION
Today, the vulnerability and future needs of the U.S. in the area of
electrical power are uppermost in the minds of the consuming public. The
energy crisis has become a complex of economic, environmental, conservation
and cost-benefit issues that must be resolved to preserve the way-of-life as
we now know it. The oil embargo showed how dependent we were on foreign
nations for the raw materials to keep oil-burning engines in operation; the
extremely cold winters of 1977 and 1978 cautioned us about our depleted
natural gas reserves and the importance of energy conservation; and the
environmental battle against nuclear power stations, coupled with the
presidential edict against fuel reprocessing operations, emphasized our
energy predicament. In addition, the latest energy plan stressed both fuel
conservation and a penalty for those industrial consumers who would not or
could not convert to coal, the dwindling coal reserves resulting from labor
disputes notwithstanding.
f
The search for alternative sources of energy plus the need for energy
conservation is a must. But the fact that population growth and electrical
power requirements have been increasing more rapidly than electricity
generating capacity has aggravated this problem.^' This observation is
graphically depicted in Figure 1, and predicts the situation that will be in
existence at the turn of the century. In spite of the most stringent
conservation efforts or the effectiveness of alternative sources of
electricity, power requirements should more than double over the next 20
years.
The alternative sources of electrical power do not give us cause to
be optimistic. Solar, hydroelectric and geothermal power are potential
sources, but in the opinion of the experts, their full-scale operation is at
least 10 years away. A similar prediction is made for coal degasification
operations, which will utilize all types and grades of coal without
pretreatment. Since the present state of the art is pilot plant evaluation,
since gas and oil reserves are severely limited, and since there remain many
environmental problems connected with the construction and operation of
nuclear power stations, the main thrust in the energy picture today is that
additional coal burning power plants must be built. Our electrical needs
may be satisfied if these are brought rapidly into operation, but to
accomplish this, the fossil fuel economy must undergo major changes, and
energy consumption must be controlled.
The United States has an almost inexhaustible supply of fossil fuel,
which today accounts for more than half of the thermal electrical energy
production. A conservative estimate^2) puts the availability of our coal
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10
20
30
40
1950
60
70
80
90
Figure 1. Growth of population and energy consumption from 1900 to present
and predictions to 2000.
V?
O
Ul
VI
O
O
?
-J
i
60
2000
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reserves at 200 years or more, with deposits in more than 30 states that are
potentially developable for commercial purposes. Fuel production
operations, however, have not been able to keep up with the unusual increase
in coal consumption, especially during periods of labor disputes.
The ineffectiveness of present mining techniques usually results in
the discarding of potential coal reserves in the overall process. Because
of the projected heavy demand for fuel, this waste product needs to be
recovered. And, as these demands increase, mining operations will become
less selective, and a poorer grade of ore will be extracted. This projected
increase in coal consumption, coupled with the decreasing quality of
available coal, will also result in substantially increased quantities of
coal ash.
The geological and geographic factors associated with the fossil fuel
beds determine the nature of the ultimate residue; the actual mining devices
determine the extent of environmental insult. Even with low sulfur coal,
mined primarily in Western U.S., several million tons of S02, N02 and
particulates find their way into the environment as emissions from coal
burning plants. Projecting this into the future, it is evident that double
this volume may be released in 1999.'3) The bulk of this solid waste will
be recovered from scrubber operations and therefore its disposal needs to be
considered.
The schematic diagram that shows the flow of air, fuel and ash in a
typical fossil fuel plant is depicted in Figure 2. By analyzing each
segment of the coal burning process, and with the information available
regarding plant operation, a material balance could be made and a dose
committment from releases could be calculated.
There have been investigations into the health hazards resulting from
increased use of coal and other fossil fuels - the effect of N02, S02
and particulates that are found in plant exhaust. These, however, are the
non-radioactive components from fossil fuel combustion.
There have been studies that have measured the concentration of
radium, thorium, and uranium that have been released to the environ-
ment as fly ash from the combustion of coal in fossil-fuel plant
operations.(^-5) There have been investigations that have compared stack
discharges from coal-fired plants with that from nuclear power plants and
have determined that a greater hazard results from the ^2opa emitted from
fossil fuel than from the noble gases and 131i released from a comparable
size nuclear plant.(6-8)
Therefore, if the radiation hazard from coal burning plants is to be
determined, the activity in coal and its operational by-products must be
obtained. With this information available, dose commitment results for each
component can be estimated.
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^r
SCRUBBER
FLY ASH -*•
SUPER
HEATER
ELECTROSTATIC
PRECIPITATOR
•*• TO BOILERS
FURNACE
COAL
FROM
HOPPER
MIXER
a
r
HOT AIR
BOTTOM ASH
Figure 2. Schematic of coal burning plant
depicting Sampling ports.
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SECTION 2
EXPERIMENTAL
Through the assistance of the radiation representatives of several
regional offices, samples of coal and combustion by-products were collected
during fossil-fuel plant operations. Additional coal samples were obtained
from different mines in the United States.
During this study, 75 samples of coal and products of combustion were
collected during actual operations, and shipped to the laboratory for
analysis. The quality control data relating to these aliquots, obtained
from the Federal Power Commission, indicated the annual operating experience
of these plants. The radionuclides present in these fossil fuels were then
determined using radiochemical procedures applicable to liquid samples. The
methods had to be modified to assure quantitative recovery of all activity.
Each sample was air dried, pulverized if necessary, ard homogenized
until uniform. In a few instances the samples were sieved to a 60 mesh size
in order to separate any non-uniform aggregates. Each sample was placed in
a 400 ml polyethylene container and filled to the mark. After recording the
tare weight, the gamma radioactivity in the sample was determined.
Radionuclides that emit gamma rays were identified by their characteristic
gamma-ray energies. A 2048-channel spectrometer and a Ge(Li) detector were
employed to obtain the spectra. Because of the low activity and the low
abundance of these nuclides, overnight and long week-end counting times were
required. Once the gamma emitters were identified, the activities of
several of them were determined and concentration factors were calculated.
The radium, thorium and uranium concentrations were ascertained by
radiochemistry using methodology applicable to aqueous samples that had to
be modified to accommodate the variety of samples and sample sizes. Testing
continued until reliable and reproducible results were obtained on replicate
determinations. The selected methods were effective for all kinds of
fossil-fuel and by-product samples and assured that all the activity was
completely solubilized at the start of the analysis.
Various methods were evaluated for solubilizing the sample matrices.
These included hydrogen fluoride digestion, Parr bomb ignition and fusion
with different flux combinations. The modified procedures appear in the
Appendix*, and are summarized as follows.
*We appreciate the cooperation and assistance of Mrs. Ann Strong, Chief,
Analysis Section, Eastern Environmental Research Laboratory, Montgomery,
Alabama, for the thorium and uranium analyses.
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1. 226Ra: The fossil-fuel sample is dried at 110°C for a few
days, cooled, pulverized and sieved for homogeneity using a sixty mesh
sieve.. In order to avoid activity loss during ignition, a weighed aliquot
(5-10 g) is carefully pre-ashed with a Meker burner.
The pre-ashed sample is placed in a muffle furnace and ashed
overnight or longer if the ashing is incomplete. During this operation the
temperature is slowly increased to 600°C. The sample is cooled and
weighed to determine ash content. For the initial solubilization, a 1-gm
aliquot is fused with an alkaline flux and dissolved with strong acid. The
BaSOij, carrying the radium activity, is precipitated, dissolved and
transferred to a radon bubbler. The radon in the sample is deemanated, and
the bubbler is set aside for about a week for the ingrowth of 222Rn from
its 22°Ra parent.
The radon that has grown in is deemanated into a calibrated
scintillation cell, and the radon and its alpha-emitting daughters are
allowed to come to equilibrium. The 222Rn ^n the cell is determined with
an alpha scintillation counter.
This modification of the radon emanation' technique'9) assures
complete dissolution of the sample and quantitative measurement of radium
activity.
2. Uranium and Thorium: The fossil-fuel sample is dried at 110°C
overnight, cooled, pulverized and sieved for homogeneity using a sixty-mesh
sieve. Up to 5 g of sample is ashed in the muffle furnace at 550°C
overnight.
The ashed sample is transferred to a teflon beaker and standardized
232{j and 23^Th tracers are added for yield calculations. After an HF
digestion, the residue is transferred to a platinum crucible for a
pyrophosphate fusion. Sulfuric acid digestion, evaporation to fumes and
dissolution in hydrochloric acid complete the solubilization.
Uranium is extracted into triisoctylamine and coprecipitated with
lanthanum fluoride. The thorium in the acid phase of the extraction is
purified by anion exchange and coprecipitated with lanthanum fluoride.
The planchets are counted by alpha spectroscopy to determine the
uranium and thorium isotopes, respectively. This improvement of existing
methodology^10-11^ enables all the activity to be determined on the same
aliquot.
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SECTION 3
RESULTS
Gamma Spectroscopy - The gamma-ray activities in the coals, ashes and
sludges were found to be a function of the source and type of fuel
combusted—a fact which was recently reported.'12) Although most of the
nuclides were evident in all samples, there were some differences. As
evidenced by differences in photopeak height, none of the activities were
lost during combustion, but were concentrated in the ash. The Ge(Li)
spectra of these samples revealed the presence of the 23o\j and 232^
series and indicated qualitatively what could be expected in stack releases.
An indication of what activities may be present can be obtained by
comparing the gamma photopeaks of the coal and fly ash samples with that of
normal background. The peaks that have been identified verify the presence
of 214pb, 226Ra, 21^Bi, and ^°K. These scans are shown in Figure 3,
and refer to coal and by-products collected from operating plants in Ohio
and Kentucky. A similar compilation was made recently on Western
Pennsylvania coal plant operations. The small differences that existed were
attributed to differences in equilibrium that had been attained in the
respective coal fields and to different coal mining operations.
Radiochemical Analyses - Methodology for determining radium, thorium
and uranium in aqueous samples have been tested and found quite reliable for
many years. The scientific literature has described these procedures, and
reported on modifications that were required when samples of silt, biota and
vegetation were analyzed. Several procedures were evaluated by replicate
analyses of the coal and ash samples. The non-agreement of results
suggested that the sample was not completely in solution, and initial
treatment had to be more rigorous to overcome this obstacle.
Investigations involving replicate analysis of coal and ash samples
demonstrated that an acceptable treatment consisted of ashing and
hydrofluoric acid digestion in platinum, ashing overnight at high pressure
in a Parr bomb capable of handling one gram samples and finally an
assortment of flux fusions. For some samples one of these treatments was
sufficient, but it was generally agreed that a universal dissolution
technique for all coal and by-product samples would assure uniformity of
analytical results and provide reliable values for dose calculations. An
alkaline borax flux was determined as satisfactory for all samples. Using 8
g of flux per gram of sample assured complete dissolution of the sample
which was subsequently purified as the sulfate and dissolved for radon
emanation analysis.
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1,000,000
00
100,000 .
200
1800
Figure 3. Ge(Li) spectra comparing instrument background,
Kentucky coal, and electrostatic precipitated fly ash.
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The initial preparation of samples for the uranium and thorium
procedures included prior ashing, a hydrofluoric acid digestion, plus a
pyrosulfate fusion. This meant that for the uranium and thorium extractions
to be considered complete,- both a digestion and fusion technique were
necessary.
Although the same procedure was employed on'all samples, obvious
differences were noted in the appearance of the ash initially and in
subsequent steps. Dependent on the nature of the coal sample, the ash took
on a reddish, whiteish or grayish texture. Despite differences in
appearance, the ash was readily solubilized during the fusion treatment, and
the final separation was a purified precipitate.
After obtaining the gamma spectra for these samples, the areas under
the 187 keV 22^Ra and the 1462 keV ^°K photopeaks were summed and
quantified. The 22°Ra was then determined by radiochemical analysis using
the modified radon emanation technique. Comparing the values listed in
Table I, it can be concluded that the 2 error associated with gamma
spectral analyses, results in values that are significantly higher even with
a 1000-minute counting time. This difference may be attributed to the
235y contribution to the 0.186 MeV peak. As an indication of the presence
of 22°Ra and other nuclides in the uranium and thorium series,
non-destructive spectral analysis is satisfactory if long counting time is
available, but for the measurement of this activity and the calculation of a
radiation dose, radiochemical analysis is required.
The analytical results indicate small differences in the 22°Ra in
coal, the average value being less than 1.0 pCi/g. The activity in the ash,
however, varies as a function of the plant operation and possible prior
treatment of the fossil fuel following mining operation. A 1-10 fold
concentration has been observed and similar results have been described in
the literature. Generally speaking, the levels in fly ash and bottom ash
indicate possible differences in mining and coal washing operations, and
differences in the source of the fossil fuels.
The results from the radiochemical analyses of samples from the
Louisville, Kentucky power plant one year apart are listed in Table II. No
stack samples could be collected, so no activity balance is possible. The
aliquots for the uranium, thorium and 226pa analyses were taken at the
same time so that a close correlation of all activities could be made. From
this data it can be concluded that radioactive composition varies as coal
sources vary. This will result when the natural acitivity is in a different
state of equilibrium at the time of mine operations.
It is generally accepted that a 1000-megawatt power plant, the
average capacity for a fuel plant, burns 2 x 10" tons of coal annually.
Even though the sources of coal in the United States do vary with respect to
chemical composition, ash content, burn-up and activity, average values have
been selected in order to calculate a radiation dose. The Louisville Gas
and Electric Company has indicated that the ash content of coal last year
averaged 15$. This value is a little higher than the norm, and indicates
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Table 1
Comparison of Non-Destructive and Radiochemical Analyses of
Sample 4°K 226Ra, pCi/g
Identification pCi/g Spectral Result Radiochemical Analysis
Coal:
W. Ky 3/76 3.6 + 1.0 1.'7 + 1.2 0.49 + 0.01
W. Pa 4/76 8.3 +0.5 1.0 + 0.2 0.49 + 0.01
E. Pa 4/76 8.1 + 0.05 1.1 + 0.2 0.55 + 0.01
E. Ky 11/76 4.2 + 0.4 1.3 + 0.5 0.49 + 0.02
Ohio 6/76 4.4 + 0.3 0.4 + 0.3 0.29 + 0.01
W. Montana 5/76 1.1 + 0.2 0.7 + 0.5 0.65 + 0.20
E. Ky 4/77 6.2 + 0.4 1.6 + 0.4 0.56 + 0.01
W. Ky 4/77 4.6 + 0.2 1.1 + 0.3 0.59 + 0.04
Fly Ash:
W. Pa 4/76 23.0 + 0.9 4.6 + 0.3 1-36 + 0.02
Ohio 6/76 18.0 + 1.0 8.8 + 0.6 4.04 + 0.07
E. Ky 11/76 18.0 + 2.0 5.8 + 1.0 3.86 + 0.07
W. Ky 4/77 19.0 + 1.0 7.2 + 0.5 3-92 + 0.07
Bottom Ash:
E. Ky 6/76 15.0 + 1.0 10.6 + 1.0 4.89 + 0.11
E. Ky 6/77 18.5 + 0.7 7-5 + 0.7 3.08 + 0.07
10
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Table 2
Radiochemical Analysis of Coal and Coal By-Products, pCi/g
234.
226
235
238.
228.
230,,
Date
6/76
6/77
Identification Ra
E.
W.
W.
W.
E.
W.
W.
W.
Ky.
Ky.
Ky.
Ash
Ky.
torn
Ky.
Ky.
Ky.
Ash
Ky.
torn
Coal
Coal
Fly
Bot-
Ash
Coal
Coal
Fly
Bot-
Ash
0.28±0.01
1.98+0.01
7.0 ±0.1
5.0 ±0.1
0.46±0.01
0.72+0.01
3.8 ±0.1
3.1 ±0.1
U
0.54+0.07
0.80±0.10
6.3 ±1.1
5.6 +0.8
0.56+0.16
0.92+0.10
4.2 +0.5
2.7 ±0.4
0.
0.
0.
0.
0.
0.
0.
0.
U
03+0.01
04+0.01
33±0.09
22+0.07
07±0.02
05±0.02
20±0.07
09±0.04
U
0.51+0.07
0.78+0.03
8.6 ±1.1
5.5 ±0.8
0.58+0.12
0.92±0.10
4.4 +0.5
2.7 ±0.3
Th
0.40+0.04
0.21+0.03
1.9 +0.1
1.9 ±0.4
0.60±0.08
0.34±0.04
1.8 ±0.2
1.7 ±0.2
Th
0.46±0.03
0.71±0.05
6.5 ±0.3
6.0 ±0.7
0.61+0.13
0.85±0.05
4.5 +0.3
i
2.7 +0.3
Th
0.30+0.03
0.19±0.02
1.8 ±0.1
1.6 ±0.3
0.39±0.09
0.27+0.03
1.57±0.18
1.3 ±0.2
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the possibility of poorer grade of coal being mined. Continued
deterioration can be expected in the future.
With this information and with our results, the following
calculations evolve:
The annual total ash production would be 3 x 10^ tons (2 x
tons x 0.15); divided into bottom residue (15%) and fly ash (85?). The
quantity of bottom ash, 4.5 x 101* tons (3 x 10^ tons x 0.15) is normally
buried and completely covered for disposal. Airborne pollution will be
negligible from this operation, and no hazard from the alpha activity will
result.
The 3 x 105 tons of fly ash that are generated annually are
collected by electrostatic precipitation followed by stack scrubbers. This
fly ash is normally used in the building trades or road improvement
operations. If the coal ash is incorporated in concrete and concrete
products as a replacement for cement, radon emanation may become a problem,
and regular monitoring would then be required. Past experience has shown
that a radiation problem may result from possible radioactive emanations
from walls and floors of buildings constructed from this material. Other
uses of the fly ash have been in reclaiming surface mine spoil and as a soil
nutrient.
The efficiency of electrostatic precipitators has been rated at
90-95?. Hence most of the fly ash will be trapped in this operation.
Effectively operating scrubbers which can clean up about 80-90? of the stack
influent will collect that fraction of the residue. Hence, about 5000 tons
of fly ash could find its way into the environment as stack gas effluent.
Subsequent methods development and radiochemical analysis for 22°Ra
and the other important nuclides entering the fossil fuel plant stack as
gaseous effluent may provide a more accurate determination of the activity
balance that is experienced when coal is burned in 1000 megawatt fossil fuel
power plants for one year- The data obtained in the radiochemical analysis
of coal, fly ash and the other by-products were used to calculate the
following assessment which is shown in Table III.
This assessment is based only on the grab samplings of the coal, fly
ash and scrubber sludge and the 22^Ra content as determined by our
procedures. Levels of 22^Ra ±n coai as indicated in the literature ranged
from 0.2 - U.O pCi/gm of coal, from 3-0 - 10.0 pCi/gm of fly ash and from
0.2 - 1.0 pCi/gm dried scrubber sludge. Depending on the source of mining
operations, the 20 mCi 22*>Ra that is calculated as an average discharge
from a 1000 megawatt plant may be a conservative estimate. The activity
levels selected for this assessment can also be much higher. In any event,
direct measurement of the activity in the stack effluent will provide a more
reliable estimate of radiation dose.
12
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Table 3
By-Product Production and 22^Ra Activity Data
for a 1000 Megawatt Fossil Plant
Component
Coal
Bottom Ash
Fly Ash
Scrubber
Sludge
Stack
Effluent
Annual
Production,
tons
2 x 106
0.05 x 106
0.3 x 106
0.1 x 106
5000
Average
Activity,
pCi/g
0.9
5.0
5.0
0.5
5.0
Total Acti-
vity Available
Annually,
Ci/yr
1.65
0.23
1.35
0.05
Potential
Annual
Discharge,
Ci/yr
0.02
13
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The foregoing analytical and calculated results plus general
operation data and assumptions are to be utilized to calculate the annual
dose rate. The criteria have been compiled in a report soon to be
published.
These then are the assumptions:
1. Electrostatic precipitators and stack scrubbers operate at
maximum efficiency.
2. Operating information:
Stack height - 500 ft. (150 m.)
Average stability -neutral condition
Max. downwind concentration - at 5.5 km (3.4 mi.)
Wind direction - SSW to NNE - 15% of the time
Average wind speed - 8.4 mph
Regular source of fuel
3. Relatively flat terrain between stack and receptor.
4. No plume rise due to buoyancy of heated effluent.
The critical organ for 22^Ra, which is designated as a "W
compound*", is the bone, where the dose limit has been set at 25 mrem/yr.
The average annual concentration of 22°Ra that is released from a 1000
megawatt coal burning plant is 20 mCi or 2.4 x ID'11 Ci/m3. The dose to
the bone for this activity is 3.7 x 10~2 mrem/yr. or 2 x 10~3 of the
bone dose limit. The radiation dose to the lungs for the 22°Ra discharge
is about a factor of 10 lower.
Similar calculations for the 232Th and 23^u being emitted from
the plants indicated only a small fraction of the allowable radiation dose
occurring. The chemical toxicity from these was more significant.
In summary, then, a very minimal radiation hazard results from the
discharges from present-day coal plants under the optimum conditions
stated. However, if scrubbers are not employed, or if these collectors
operate at less than maximum efficiency, the radiation hazard may become
significant. If present coal supplies are replaced with fuel of a higher
radioactive and ash content, an increase in the radiation hazard could
result. For the present, the greater hazard results from mining and
pre-combustion operations, and it is these activities that must be carefully
monitored. Therefore, if plant operations are carefully monitored, an
expanding fossil- fuel economy need not have a serious environmental
radiation impact.
*A "W compound" is defined as one having a clearance time of a few
days to a few weeks.
14
-------
The procedures which have been developed for measuring ""Ra,
and 23°u ^n COal and coal by-products have been instrumental in
calculating an activity balance in a coal plant operation. From these
radiochemical results, the minimal radiation hazard could be calculated.
15
-------
REFERENCES
1. "Outlook for Coal" - ACS Symposium on Coal Dilemma, Feb. 1977.
Report in Chem. and Eng. News, Feb. 14, 1977.
2. Guerrieri, S.A. "Achieving Energy Self-Sufficiency With Coal,"
Combustion, 11-22 (April 1977).
3- "Trends in Powerplant Capacity and Utilization - Inventory of
Powerplants in the United States." Report, Federal Energy
Administration, Washington, D.C. (1976).
4. Eisenbud, M. and Petrow, H., "Radioactivity in the Atmospheric
Effluents of Power Plants that Use Fossil Fuels". Science, 144,
April 17, 1964.
5. Marquardt, W., Hoehle, R., and Schub, U., "Radioactive Emissions by
Coal-Fed Power Stations." Z. Gesamte Hyg. Ihre Grenzgeb 16, 188-191
(1970).
6. Martin, J. E., Harward, E. D., Oakley, D. T., "Comparison of
Radioactivity From Fossil Fuel and Nuclear Power Plants." DHEW,
Bureau of Radiological Health, Public Health Service Report, Appendix
14 (Nov. 1969).
7. Hull, A. P., "Some Comparisons of the Environmental Risks from
Nuclear and Fossil Fueled Power Plants." Nuclear Safety, 12 (3)
185-196 (1971).
8. Terrill, J. G., Harward, E. D., Leggett, I., "Environmental Aspects
of Nuclear and Conventional Power Plants." Industrial Medicine and
Surgery, 36, 412-418 (June 1967).
9. Rushing, D. E., "The Analysis of Effluents and Environmental Samples
from Uranium Mills and of Biological Samples for Uranium, Radium and
Polonium." SM/41-44, Symposium on Radiological Health and Safety,
Vienna, Austria (1963).
10. Hyde, E. K., "The Radiochemistry of Thorium." National Academy of
Sciences, National Research Council, NAS-NS 3004 (I960).
11. Grindler, J. E., "The Radiochemistry of Uranium." National Academy
of Sciences, National Research Council, NAS-NS 3050 (1962).
16
-------
12. Barber, D. E., Giorgio, H. R., "Gamma-Ray Activity in Bituminous,
Sub-bituminous and Lignite Coals." Health Physics, 32, £, 83-88
(Feb. 1977).
13. Blanchard, R. L., Kolde, H. E., Montgomery, D. M., "Criteria for the
Estimation of Radiation Dose." Office of Radiation Programs, U. S.
E.P.A. (to be published).
17
-------
APPENDIX
Methods of Analysis
I. Pretreatment of Samples (Note 1)
A. Coal - Take an aliquot (20-30 g), grind in a mortar and put
through a 60-mesh sieve. Transfer to a tared porcelain dish, weigh and
pre-ash with a Meker burner. The pre-ashing must proceed carefully and
slowly- Starting with a low flame, to keep losses at a minimum, gradually
increase the flame until all gases are released and the carbon deposits are
burned off the rim of the dish. Continue ashing overnight in a muffle
furnace at 600°C. After cooling and weighing, take a 1 gm aliquot of the
ash for the initial alkaline fusion step.
B. Bottom Ash - Take an aliquot (5-10 gm), grind in a mortar, put
through a 60-mesh sieve and transfer to a porcelain dish. Ash overnight in
a muffle furnace at 600°C, cool, weigh and take a 1 gm aliquot for the
initial alkaline fusion step.
C. Fly Ash - Ash an aliquot (1-2 g) overnight in a muffle furnace at
600°C. After cooling, take a 1 gm aliquot for the initial alkaline fusion
step.
D. Scrubber Sludge - Dry an aliquot (5-10 g) in a drying oven
overnight at 105°C. Transfer to a mortar and grind till uniform. Ash
overnight in a muffle furnace at 600°C. After cooling, take a 1 gm
aliquot for the initial alkaline fusion step.
II. Radiochemical Analytical Procedures
A. Radium-226 Analysis - Radon Emanation Technique (Fig. 4).
1. Principle of Method
The radium in the coal and by-product sample is recovered
by an alkaline fusion of a pretreated ash. The melt is
dissolved in sulfuric acid and the activity is concentrated and
separated by coprecipitation with barium as the sulfate. The
precipitate is dissolved in EDTA, placed in a bubbler,
deemanated, sealed and stored for ingrowth of 222Rn.
2. Reagents
Radioactive tracer standard: 22°Ra
Alkaline flux reagent - prepared reagent
Ammonium hydroxide, NHiiOH: 15 N (cone.)
Ascarite: drying reagent, 8-20 mesh
18
-------
Barium carrier: 16 rag/ml
EDTA reagent: 0.25 M (Note 2)
Helium gas
Hydrochloric acid, HC1: 12 JI (cone.)
Hydrogen peroxide, H202: 3%
Magnesium perchlorate, Mg(C10i|)2
Potassium carbonate,
Sodium carbonate,
Sodium borate decahydrate, Na2Bi}07' 10H20
Sodium hydroxide, NaOH: 10 N
Sulfuric acid, H2SOij: 36 N (cone.), 18 N, 0.1 N
3. Procedure
a. Prepare an alkaline flux reagent (Note 3), and store in an
air-tight bottle.
b. For each gram of ashed sample, mix thoroughly with 8 g of
the alkaline flux reagent in a 100 ml platinum dish. Fuse the
sample by heating with a blast burner, swirling until the melt
is a clear red, then continue heating for 20 minutes. Cool.
c. Place crucible with melt in a covered beaker containing 120
ml water, 20 ml 36 N H2SOn and 5 ml 3% H202 for each 8
g of alkaline flux reagent. When solids are dissolved, remove
and rinse dish, adding rinse to beaker. Heat solution and
slowly add 2.0 ml barium carrier. Continue stirring and
heating for 30 minutes. Allow the precipitate to settle
overnight, decant and discard supernatant.
d. Slurry the precipitate and transfer to a centrifuge tube
with a minimum amount of 0.1 N H2S04- Centrifuge and
discard supernatant. Wash twice with 0.1 N H2SOij and
discard washes.
e. Add 20 ml EDTA reagent, heat in a hot water bath and stir
well. Add a few drops 10 N NaOH if the precipitate does not
readily dissolve (Note 4).
f. Transfer the solution to a radon bubbler (Fig. 5). Open
both the upper and lower stopcocks and deemanate the solution
by slowly passing helium gas through the bubbler for about 20
minutes.
g. Close the two stopcocks, and record time. Store the
solution for U to 8 days for ingrowth of 222Rn (Fig. 6).
h. At the end of the storage period, fill the upper half of an
absorption tube with magnesium perchlorate and the lower half
with ascarite (Note 5). Attach the tube to the radon bubbler
and then attach the evacuated scintillation cell (Fig. 7) to
the tube.
19
-------
-Scintillation Cell
Manometer, I 1/2mm, 1.0.
Capillary T-Tube
Thermometer Capillary
Anhydrous Magnesium Perchlorcta
Ascarite (8-20 mesh)
Aged Air. From Compressed
Air Regulator
Radon Bubbler
— Mercury Reservoir
Figure 4. Radon Emanation Apparatus with Scintillation Cell
20
-------
<:
135
<
<
33
Liquid^
Level
mm
I7mrn^
•>
^±
mm
->
^ -
ii
* — 7mm O.D.
k
ff^
*— - -—
ViT^-lfi
X
1
^
&35mm^
"1 ^\ Corning No. 2
1 .s^ or Equivalent
~^^^
=^C
f
l^ Bubble Trap
^ 7 mm I.D.
rtigiuiiy Draco
7mm Capillary Tubing
* IV? mm I.D.
Fritted Glass Disc
/" 10-15 micron pores
Volume to be kept
at minimum
Figure 5. A Typical Radon Bubbler (emanation tube)
21
-------
to
1.0
0.9
0.8
I 0-7
k_
J3
| 0.6
^0.5
° 0.4
I 0.3
o
o
£0.2
O.I
0.0
10
Days
15
20
Figure 6. The Growth of Radon-222 from Radium-226.
-------
i. Open the stopcock on the cell and check the assembly for
leaks. Gradually open the outlet stopcock on the bubbler, and
when the stopcock is fully open and no further significant
bubbling takes place, close the stopcock.
j. Adjust the aged air or helium gas pressure so that the gas
flows at slightly above atmospheric pressure.
k. Connect the hose to the bubbler inlet and gradually open
the inlet stopcock using the bubbling as a guide. When the
stopcock can be fully opened without a significant amount of
bubbling, the bubbler is essentially at atmospheric pressure
again.
1. Open the outlet stopcock very slightly and allow bubbling
to proceed at a rate, determined by experience, such that 15 to
20 minutes are required to complete deemanation.
m. Toward the end of the deemanation, when the vacuum is no
longer effective, gradually increase the helium gas pressure.
When the system is at atmospheric pressure, shut off the helium
gas, disconnect the .tubing from the bubbler inlet and close the
inlet and outlet stopcocks of the cell and bubbler, and record
time. This is the beginning of 222Rn decay and ingrowth of
222Rn daughters.
n. Store the scintillation cell for at least 4 hours to ensure
equilibrium between radon and radon daughters. Count the alpha
scintillations from the cell in a radon counter with a
light-tight enclosure that protects the photomultiplier tube.
Record the counting time to correct for the decay of 222Rn.
4. Calculation
Calculate the concentration, D, of the 22°Ra activity in
picocuries per gram as follows:
D- C 1 _J_ ^3
D 2.22 EV A ^ A --1*
where:
C = net count rate, counts/minute (Note 6),
E = calibration constant for the deemanation system and the
scintillation cell in counts per minute/disintegrations per
minute of 222Rn (Note 7),
23
-------
67mm
90mm
Phosphor
^Coated
Clear Silica
V/indow
Corning No. 2
or Equivalent
Brass Collar
Kovar Metal
lit lit H HUHilllII IIJ U
50 mm
Figure 7. A Typical Scintillation Cell for Radon Counting
24
-------
V = sample aliquot in grams,
t-1 = the elapsed time in days between the first and second
deemanations (steps g and m) and A is the decay constant of
222Rn (0.181 d-1),
^2 = the time interval between the second deemanation and
counting and X is the decay constant of 222Rn (0.00755
hr~l), and
^3 = the counting time in minutes and A is the decay constant
of 222Rn (1.26 x 10-4 min"1).
Notes:
(1) Sample weight prior to ashing should be obtained, as well
as the weight of the ashed aliquot used in analysis. This
information is of value for relating pCi/g ash to pCi/g
original sample.
(2) Preparation of 0.25 M EDTA reagent - Dissolve 20 grams
NaOH in about 750 ml water, heat and slowly add 93 grams
Na2c10Hl4°8N2'2H2° (disodium ethylenedinitri-
loacetate dihydrate) while stirring. After the salt is in
solution, filter through coarse filter paper and dilute to 1
liter.
•
(3) An alkaline flux reagent is prepared by mixing thoroughly
30 mg BaS04, 65.8 g K2C03, 50.5 g Na2CC>3 and 33-7 g
^26407• 101^0 in a 500 ml platinum dish. Heat
cautiously to expel water. Using a blast burner, fuse the
mixture by swirling constantly during the heating. Cool the
mixture, transfer to a large mortar and grind until the fines
pass through a 10-mesh screen. Store in an air-tight bottle.
(U) The volume of these bubblers is usually greater than 20 ml
allowing for at least a 1 cm air space between the bubbler and
the stopper. In those instances where the solution volume
exceeds the capacity of the bubbler, it will be necessary to
continue the boiling in the water bath until the volume is
reduced.
(5) For minimizing corrections that would be required in
subsequent calculations, the voids above the bubbler must be
kept very small. Capillary tubing should be used whenever
possible, and the drying tube volume with the Ascarite and
magnesium perchlorate must be kept to a minimum. A typical
system consists of a drying tube 10 cm x 1.0 cm (I.D.), with
each of the drying agents occupying 4 cm and being separated by
small glass wool plugs. The column can be reused several times
before the chemicals need to be replaced.
(6) After each analysis, flush the cell three times by
evacuation and filling with helium, and store filled with
helium at atmospheric pressure. This procedure removes radon
25
-------
from the cell and prevents the build-up of radon daughter
products. Before each analysis, the scintillation cell should
be evacuated, filled with helium and counted to ascertain the
cell background.
(7) The calibration constant, E, is determined as follows:
(a) Place 50 pCi of the 226Ra standard solution in a
bubbler (50 pCi of 226Ra will produce about 6 pCi
222Rn in 18 hours). Attach the bubbler to the assembly
as shown in Fig. 4.
(b) With the scintillation cell disconnected, bubble
helium gas through the solution for 20 minutes.
(c) Close both stopcocks on the bubbler to establish zero
time for ingrowth of 222Rn. Set aside for approximately
18 hours..
(d) Evacuate the scintillation cell and attach to the
column and bubbler.
(e) Proceed with steps i-m, 22"Ra-Radon Emanation
Technique.
(f) The calibration constant, E, is determined from the
22°Ra activity in the bubbler and the ingrowth time of
222Rn by the equation:
E =
A(l-e~Xtl)(e U2)
where:
C = net count rate, counts/minute,
A = activity of 22°Ra in the bubbler (d/m),
tl = ingrowth time of 222Rn in hours,
t-2 - decay time of 222Rn in hours occurring between
deemanation and counting, and
A = decay constant of 222Rn, 0.00755 hour -1.
The calibration constant, E, includes the deemanation
efficiency of the system, the counting efficiency of the
cell, and the alpha activity contributed bv 2l8Po and
^l^Po, which will be in equilibrium with 222Rn when
the sample is counted 4 hours after the deemanation. A
100-minute counting time will be sufficient for the
standard and will eliminate the need to correct for decay
of 222Rn, which occurs during counting.
26
-------
The bubbler used for the oRa standardization should
not be used for sample analysis. It should be set aside
to be retained for future calibrations. Each
scintillation cell should be calibrated periodically with
the 226fla standard to ensure instrument quality control.
B. Uranium and Thorium Analysis
1. Principle of Method
an(j 23HTJ-J tracers are added to a pretreated ash of a
coal or by-product sample. Silicates are removed by repeated
HF evaporations. A pyrosulfate fusion solubilizes the residue,
and the final solution is made 8 N^ in HC1. Uranium is
separated by extraction with triisooctylamine, back extracted
with water, coprecipitated with lanthanum fluoride for counting
by alpha spectroscopy . Thorium activity, which is not
extracted, is concentrated on an anion column, eluted with HC1,
and coprecipitated with lanthanum fluoride for counting by
alpha spectroscopy.
2. Reagents
Radioactive tracer standards: 232y an(j 234 Th
Ascorbic acid, C6H805: Crystals
Ethanol, C2H5OH: 95?
Hydrochloric acid, HC1: 12 N (cone.), 8 N, 6 N, 2 N, IN
Hydrofluoric acid, HF: 28 N (cone.), 5% (3 N)
Lanthanum carrier: 0.10 mg/ml
Nitric acid, HNC^: 8 N, 6 N, 0.1 N
Perchloric acid, HClOij: 70% (cone.)
Potassium fluoride, KF: solid
Potassium pyrosulfate, ^8207: solid
Sulfuric acid, ^SCty: 6 N
Titanium trichloride, TiC^: 0.4? (freshly prepared)
Triisooctylamine/xylene solution, TIOA/xylene: 10%
3- Procedure
a. Add 1-5 g (Note 1) of ashed sample to a 50 ml teflon
beaker. Add 1.0 ml each of 232U and 234Th tracer
solutions. Mix.
b. Add 28 N^ HF (5 ml HF per gm ash) and evaporate to dryness
at a low heat. Repeat 3 more times with 10 ml volumes of HF to
volatilize the silica. Additional treatment may be necessary
if residue remains.
c. Add 25 ml 12 N HC1 and evaporate to dryness.
d. Transfer the powdery residue to a platinum crucible. Add 2
g KF for each gram of ash used and fuse with a Meker burner for
27
-------
30 minutes. Continue swirling, then add 3 g K2S20j for
each gram of ash and continue fusion for another 30 minutes.
e. Cool the crucible in an ice bath, add 15 ml 12 {£ HC1 and
evaporate to dryness. Slurry residue with water, transfer to a
beaker, bring volume to 150 ml, and evaporate to dryness.
f. Take up residue with 100 ml 6 N f^SOij and evaporate
past white fumes.
g. Add 10 ml 12 N[ HC1 and evaporate to dryness. Repeat.
h. Add 115 ml 8 II HC1 to dissolve residue and transfer to a 1
liter separatory funnel.
i. To the solution in the separatory funnel, add 100 ml of a
IQ% TIOA/xylene solution. Shake for 2 minutes and after the
phases separate, drain the aqueous acid solution into a beaker
and reserve for thorium analysis, step s.
j. To the organic phase add 50 ml 8 N HC1 and shake for 20
seconds. Discard the aqueous wash solution.
k. Add 100 ml 0.1 JJ HNOg to the separatory funnel and shake
for 2 minutes. Drain the aqueous layer into a 250 ml beaker.
1. Repeat step k, adding the aqueous fraction to that in the
250 ml beaker. Evaporate to dryness.
m. Add 10 ml 8 fl HNO^, evaporate to dryness. Repeat.
n. Wet ash again with 5 ml 8 JI HC1 and 5 ml HC10j4 and
evaporate to dryness.
o. Add 10 ml 12 N[ HC1, evaporate to dryness. Repeat.
p. Dissolve residue in 10 ml 1 II HC1, plus a pinch of ascorbic
acid to reduce the iron. Add 1.0 ml lanthanum carrier, 1 ml of
freshly prepared 0.4$ TiCl3 and 2 ml 5% HF. Stir well, and
let stand 30 minutes.
q. Filter through a 25-mm nucleopore filter (0.2 u pore
size). Wash three times with 10 ml portions of alcohol. Mount
on a s.s. planchet using double-stick tape to secure the sample.
r. Count for 1000 minutes, using an alpha spectrometer to
determine ^U, 235u, and 23°U; and for the chemical
recovery of 232U. (Note 2).
s. Evaporate to dryness the aqueous acid solution from step i
which contains the thorium activity.
28
-------
t. Wet ash the residue with 10 ml 8 N_ HNC>3 and evaporate to
dry ness. Repeat.
u. Add 5 ml 8 N[ HC1 and 5 ml HC104 and evaporate to dryness.
v. Add 10 ml 8 1} HNO^ and evaporate to dryness.
w. Take up the residue in 100 ml 6 N HNC>3 and heat until
dissolved.
x. Cool and pass over prepared anion resin column (Note 3) at
gravity flow. Discard effluent.
y. Wash the resin column with 100 ml 6 ^ HC1 and collect the
eluate in a 400-ml beaker; evaporate to dryness.
z. Add 10 ml 8 N HNO^ and evaporate to dryness. Repeat.
aa. Add 10 ml 2 IJ HC1 and evaporate to dryness. Repeat.
bb. Dissolve residue in 10 ml 1 N^ HC1, add 1.0 ml lanthanum
carrier, 2 ml 5% HF and stir well. Let stand for 30 minutes.
cc. Filter through a 25-mm nucleopore filter (0.2 u pore
size). Wash three times with 10 ml portions of alcohol. Mount
on a s.s. planchet using double-stick tape to secure the sample.
•
dd. Beta count for 10 minutes to obtain 23^Th recovery (Note
4). Count for 1000 minutes, using an alpha spectrometer to
determine 232Th, 230ih, 228Th, and 22?Th.
Notes:
(1) If only 1 g samples are used, the fusion step (d) can be
eliminated, since the HF and HC1 treatments will completely
solubilize the sample. The procedure can continue with step
(h).
(2) A 232u standard used for determining chemical recovery
of uranium is prepared by pipetting 1.0 ml 232u tracer (f*3
dpm) into a beaker and coprecipitating as described in steps p
and q. Count 1000 minutes using an alpha spectrometer.
(3) Preparation of anion resin - Slurry anion resin (Dowex
1-X8 or equivalent) (50-100 mesh) with water and transfer to a
column 1.0 cm (I.D.) x 20 cm until a layer 10 cm deep is
formed. Wash with 25 ml 6N HC1 followed by 100 ml water before
use.
(4) A xh standard used for determining chemical recovery
of thorium is prepared by pipetting 1.0 ml 23^Th tracer (^^
1000 dpm) into a beaker and coprecipitating as described in
29
-------
steps cc and dd. Beta count for 10 minutes on the same day
samples are counted in the alpha spectrometer.
4. Calculations
(1) Uranium
Sum the counts in the 232u standard under the 232U
peak (5.32, 5.27 MeV), and compare with the counts in the
sample under the 232u peak. For calculating the
specific isotopes of uranium, sum the counts under the
following peaks:
234(j (4.77, 4.72 MeV)
235{j (4.37, 4.40, 4.58 MeV)
238.u (4.20, 4.15 MeV)
pop
pCi 23Vg - _ cpm ^
cpin 232U in sample • Eff . fEfi x sample x
— - - x dPm slze
cpm U in standard
(2) Thorium
Compare the 23^Th beta counts in the sample to those in
the standard to determine chemical recovery. For
calculating the specific isotopes of thorium, sum the
counts under the following peaks:
232Th (4.01, 3-95 MeV)
230Th (4.68, 4.62 Mev)
228Th (5.43, 5.34 MeV)
232
c- 232 , _ cpm J Th
P X g " cpm 23V in sample _ Eff. fES x sample
r 23lti e X dpm size
cpm Th in standard
30
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/4-78-039
3. RECIPIENT'S ACCESSION-NO.
4. TITLE ANDSUBTITLE
Analysis of Radioactive Contaminants in By-Products
From Coal-Fired Power Plant Operations
5. REPORT DATE
July 1978
issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Herman Krieger and Betty Jacobs
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Rad. Methods Section, Phys. § Chem. Methods Branch
EMSL-Cinti U.S. EPA
26 W. St. Clair St.
Cincinnati, Ohio 45268
10. PROGRAM ELEMENT NO.
1BD612
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Env. Monit. and Support Lab
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
In-House __
14. SPONSORING AGENCY CODE
EPA/600/06
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The major radionuclides detected in fossil fuel power plant operations have been
identified and quantified. Samples of coal, fly ash, bottom ash and scrubber sludge
were collected from different regions in the U.S. and analyzed for radium, thorium,
and uranium. The standard radiochemical procedures were modified in order to obtain
reproducible results for the variety of samples analyzed, which then can be used to
calculate a radioactivity balance on the basis of normal operations.
The report tabulates the spectrum of activity levels in a variety of samples,
and compares the results from non-destructive spectrometry and from radiochemical
separations. The environmental impact of an expanding fossil-fuel power plant
operation is discussed, and it is concluded that for the present, no radiation hazard
exists.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Radioactive Contaminants*
Environments
Radium Isotopes*
Coal
Coal Mining
Irradiation
Gamma Ray Spectroscopy
Radiochemical Analysis
Procedures
Radiation Exposure
Environmental
Monitoring
97A
99E
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
39
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
31
•A U.S. GOVERNMENT PRINTING OFFICE: 1978-757.-14O/1376
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