oEPA
           Environmental >
           Ottice of R.uii   jrams
               ility
           PO Box 18416
            Vegas NV 891 T4
                                EPA 520 6 82 018
                                November 1982
           Radiation
Emissions Of Naturally
Occurring Radioactivity
From Aluminum And
Copper Facilities

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                                                  EPA-520/6-82-018
                                                  November  1982
   EMISSIONS OF NATURALLY OCCURRING RADIOACTIVITY
         FROM ALUMINUM AND  COPPER  FACILITIES
                         by
                  Vernon  E. Andrews
          Office of Radiation Programs-LVF
        U.S. Environmental Protection Agency
              Las Vegas,  Nevada  89114
                  Project Officer
                      Tom  Bibb
    Emission Standards and Engineering Division
        U.S.  Environmental  Protection Agency
   Research Triangle Park, North Carolina  27711
This report was prepared with the technical support
 of Engineering-Science  Inc. contract 68-02-2815,
 and PEDCo Environmental  Inc. contract 68-02-2811
 Office of Radiation Programs - Las Vegas Facility
       U.S. Environmental Protection Agency
             Las Vegas, Nevada  89114

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                                  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 use.
                                      ii

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                                    FORWARD


    The  Office  of Radiation Programs (ORP) of  the  U.S.  Environmental  Protec-
tion  Agency  (EPA)  conducts  a  national   program  for  evaluating exposure  of
humans to  ionizing  and  nonionizing  radiation.   The goal of  this  program is to
develop  and  promote protective controls necessary to  ensure the  public health
and safety.

    In  response to the  1977 amendments  to the  Clean Air  Act  the Las Vegas
Facility was  given  the responsibility  to collect field  data on  emissions to
the  atmosphere  of  natural  radioactivity from  operations  involved   in  the
mining, milling,  and  smelting of minerals  other  than uranium and  coal.  This
report  is  one  of  a  series  which  describes  an  individual  facility   and  its
associated radioactive emissions.

    ORP encourages  readers  of the report  to inform  the Director,  ORP-Las Vegas
Facility, of any omissions or errors.  Comments or requests for further  infor-
mation are also invited.
                                       Wayne A. Bliss
                                       Acting Director
                                       Office of Radiation Programs-LVF
                                     iii

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                               CONTENTS


                                                                       Page
Forward	iii
Figures	vi
Tables	vi
Abbreviations and Symbols 	 vii


   1.  Introduction 	   1
   2.  Sample Collection and Analysis 	   3
                Sample collection 	   3
                Sample analysis 	   3
                Data reporting	   4
   3.  Bauxite Mine (Aluminum Industry) 	   5
                Process description 	   5
                Results 	   5
   4.  Alumina Reduction Plant  	   7
                Process description 	   7
                Results 	   9
   5.  Aluminum Reduction Plant 	  13
                Process description 	  13
                Results	15
   6.  Underground Copper Mine and Mill	17
                Process description 	  17
                Results	20
   7.  Open Pit Copper Mine and Concentrator	21
                Process description 	  21
                Sampling points 	  22
                Sample results	22


References	28

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                                  FIGURES
Number                                                                   Page
   1  Uranium and thorium radioactivity decay schemes 	    2

                                   TABLES
Number                                                                   Page
   1  Bauxite Pit Radon Emanation Rates 	    6
   2  Radioactivity in Alumina Plant Process  Samples	    8
   3  Alumina Plant Particulate Radioactivity Rate	    9
   4  Alumina Plant Ambient and Stack Radon-222  Measurements	10
   5  Brown Mud Tailings Radon Emanation Rates	12
   6  Radioactivity Aluminum Reduction Plant  Process  Samples	14
   7  Aluminum Reduction Plant Emission Rate	15
   8  Underground Copper Mine and Mill  Process Sample Radioactivity  ...   18
   9  Underground Copper Mine and Mill  Radon-222 Measurements  	   19
  10  Open  Pit Copper  Mine  and Concentrator
      Process Sample Radioactivity	23
  11   Ambient Station  Radon-222 Concentrations - Open Pit  Copper  Mine  .  .   24
  12  Copper Mine Crusher and Concentrator -  Radon-222 Measurements  ...   25
  13   Average Annual Emissions From  An  Open Pit  Copper Mine  	   26
  14   Aerodynamic Particle  Size Distributions from
      Open  Pit Copper  Mine	26
  15   Open  Pit Copper  Mine  Radon Emanation Rates	27
                                    vi

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                       LIST  OF  ABBREVIATIONS  AND  SYMBOLS
ABBREVIATIONS


Ci   *
fCi/m3
mCi/g
nCi/nv3
pCi
pCi/g-
pCi/irr-min
TSP
urn

SYMBOLS

AMAD
EIC
GMD
GSD
HSS
MSHA
curies, 3.7 x 10]° disintegration per second
femtocuries (10~15 curies) per cubic meter
millicuries (10~3 curie) per gram
nanocuries (10'9 curie) per cubic meter
picocuries, 10~'2 curies
picocuries per gram
picocuries per square meter per minute
total suspended particulates
micrometer, 10~6 meter
activity mean aerodynamic diameter
Eberline Instrument Corporation
geometric mean diameter
geometric standard deviation
Horizontal Stud Soderberg
Mine Safety and Health Administration
                                      VI1

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                                  SECTION  1


                                 INTRODUCTION


    The Clean Air  Act,  as amended  in  August 1977, required  the  Administrator
of the Environmental Protection Agency  (EPA) to  determine  whether emissions  of
radionuclides into ambient air should be regulated under the  Act.  In  December
1979  the  Administrator  listed  radionuclides as a  hazardous pollutant  under
Section 112 of the Clean Air Act.

    The naturally occurring radionuclides most likely to be  emitted in signif-
icant  quantities  are  those  in the  uranium-238  and  thorium-232  decay  series
(Figure 1).   These radionuclides  and their  daughter products occur  naturally
in widely  varying amounts  in  the  soils  and rocks  that  make  up  the  earth's
crust.  Average  values for uranium-238 and  thorium-232 in soils  are  approxi-
mately 1.8 ppm  (0.6  pCi/g) and 9 ppm  (1  pCi/g)  respectively (1).   The  radio-
activity concentration of  each  of the daughter  products  in  the  two  series  is
approximately equal to that of the uranium-238 or thorium-232 parent.

    Almost all operations  involving removal  and  processing of  soils  and rocks
release  some of  these  radionuclides  into  the  air.    These releases  become
potentially  important  when the materials  being  handled contain  above-average
radionuclide concentrations or  when processing  concentrates  the  radionuclides
significantly above the average amounts in soils  and rocks.

    Because mining and milling operations  involve  large quantities of ore, and
because there is  little  information about how these  activities  release radio-
active emissions, EPA, in  1978, began to measure airborne radioactive emissions
from various mining, milling, and smelting operations.

    Operations were selected for  study on  the basis  of  their potential to emit
significant quantities of  naturally occurring radionuclides to the atmosphere.
Some of the  factors  in the selection  included typical  mine  size,  annual  U.S.
production,  measured  working levels  of radon daughters  in  underground mines
and  associated  ventilation rates,  production  rate  and process  of individual
facilities,  and  previous  association  with naturally occurring  radionuclides.
Usually, we  chose  to  look  at  large  facilities in order to improve the chances
of  obtaining  emission   samples  with   radioactivity   contents  significantly
greater than background.

    These  surveys were  screening  studies  designed to   identify potentially
important  sources  of emissions  of  radionuclides  into  the  air.   Any  such
sources can  then  be studied in detail  to  determine whether  or  not a national
emission standard for hazardous pollutants is needed under the Clean Air Act.

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URANIUM - 238 DECAY SERIES
                                                          THORIUM - 232 DECAY SERIES
238
U
4 5x1O»yr
!
Of
234
Th
24 da



234
Pa
6 75 hr
. /I
/,,

234
U
2.5x105yr
t
a.V
t
230
Th
8x104yr
i
0,7
>
226
Ra
1620yr
i
a.y
222
Rn
3 8da
I
a, X
218
Po
3min.

Of

214 210
Po Po
1.6x104sec. 138da.
* j '
214 / a Y 210 /„
B, ^ ' B, '* "•*
197min 5 da.

214
Pb
27 mm
/B.y 210 /ft,y 206
/ Pb / Pb
19.4yr. Stable
                    Figure 1.   Uranium and thorium  radioactivity decay schemes.

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                                  SECTION 2


                        SAMPLE COLLECTION AND ANALYSIS
SAMPLE COLLECTION


    Most  samples  were  collected   using  EPA  reference  methods  (2).   Stack
sampling points were selected  according  to  EPA Method 1,  "Sample  and velocity
traverses  for  stationary  sources."   Stack   gas  velocity  and volumetric  flow
rate were determined by EPA Method  2,  "Determination  of  stack gas  velocity and
volumetric flow rate (type S pitot  tube)."   Gas  samples  for radon-222 analysis
were collected  using  EPA Method 3,  "Gas analysis  in carbon  dioxide,  oxygen,
excess air,  and  dry molecular  weight."  Total suspended  particulates (TSP) in
ducts and exhaust stacks were  determined using EPA  Method 5, "Determination of
particulate emissions  from  stationary  sources,"  or EPA Method  17, "Determina-
tion of  particulate emissions from stationary  sources  (in-stack filtrations
method)."  High  volume ambient TSP  samples  were collected  in  accordance with
the  "Reference  Method  for the  Determination of  Suspended  Particulates  in the
Atmosphere (3)."

    Several  contractors performed  the sample  collection.   They  used  7.6-cm
(3-inch)  glass  fiber filters  for  Method 5  samples  or  5-  by 12.7-cm  (2- by
5-inch) glass fiber filters for Method 17 samples.   The  contractors used 20.3-
by  25.4-cm  (8-  by  10-inch) Microsorban  polystyrene fiber  filters for ambient
TSP  samples.   Stack and ambient whole  air  samples for  radon analysis  were
collected in Tedlar bags of 20 to 30 liter capacity.

    Generally  one  set  of duplicate   radon samples  was   collected  at  each
sampling  point   as  part  of the  quality  assurance  program.  When  possible,
duplicate Method  5  particulate samples were  collected  from  one or  two stacks
at a given facility.

    The   contractors    collected   samples   of   process   materials    so   that
radionuclide  emission   rates  could  be compared  to the  radioactivity of the
material handled at that point.


SAMPLE ANALYSIS


    The  contractors  made  mass  determinations  on  the   various  TSP  sample
fractions  before   forwarding   them  for  radiological   analysis.    Eberline
Instrument Corporation  (EIC) performed the radiological analyses of all samples

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 except  for some  duplicate radon  samples  that  were  analyzed by  EPA  in  our
 Las Vegas  laboratory as an interlaboratory cross-check.

     EIC  analyzed  process  and  TSP   samples  by  dissolving   the  samples  and
 separating  the  elements  of  interest  by  chemical  techniques.  The  separated
 uranium  and  thorium  fractions  were  counted   on  alpha  spectrometers  for
 individual isotopic quantisation.  An alpha scintillation  counter  measured  the
 polonium-210.   Lead was separated and set aside for  about  2  weeks  to  allow  for
 ingrowth  of  bismuth-210  from  lead-210.   After   the   ingrowth   period  the
 bismuth-210 was separated  from the  lead and was  counted  on  a beta counter  to
 quantitate lead-210.   Radium  was separated  and   enclosed  as  a  solution in  a
 sealed tube to allow for ingrowth of  radon  from radium-226.   After three weeks
 of ingrowth the radon gas  was  evolved and collected in an alpha  scintillation
 cell  to be counted.  Stack and ambient gas samples were  transferred  to  alpha
 scintillation  cells and counted for radon.


 DATA  REPORTING


    The  radioactivity  reported for each sample, except for radon  collected  on
 charcoal canisters,  is  the net radioactivity plus or minus twice  the  standard
 deviation  (2s).   The net  radioactivity is  the gross  sample radioactivity  minus
 the counting  equipment  background and minus either   a) for filter samples   an
 average  value  for the radioactivity content  of  a  blank filter, or b) for  stack
 radon  samples, the  ambient radon  concentration.    The standard  deviation   is
 based  only  on  the random variations inherent in radioactivity counting and  is
 propagated  through  the  various  steps to  the   final result.    This  random
 variation,  plus  the variable  radioactivity  content  of   individual  filters
 occasionally results in a  net radioactivity of   less  then zero.   Of course'
 there  is no negative radioactivity.    In these  cases,  as with  all  others, the
 net result  must be  considered  along  with the standard  deviation.   Averages  of
multiple emission samples are given with the standard error of  the mean.

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                                   SECTION 3


                       BAUXITE MINE (ALUMINUM INDUSTRY)
PROCESS DESCRIPTION


    Bauxites,  the  principle  aluminum ore,  are  known  to  have  substantially
higher levels of uranium and thorium than the parent rock  (5).  ORP  included  a
domestic bauxite mine as part of this project.

    At  the  survey site,  bauxite  was mined  from open  pits which  varied  in
approximate area from  0.3  to 30 hectares.  Typical  pit  dimensions were 40  by
700 m.  The mining company conducted pit development by expanding  the  pit  in  a
direction perpendicular to  the  long side.  Overburden removed by  dragline  was
used  to  fill  the  previously mined  area  which  was  then  reclaimed.   Dragline
operations were conducted 24 hours  per  day.   The day shift  drilled  and  loaded
blasting holes  in  the ore  which  were blasted  at  the end  of  the shift.   The
coarsely broken  ore  was hauled  by truck to  storage areas  or  to the alumina
plant.  The  high  moisture content  of overburden  and ore  prevented  production
of  airborne  particulates  during  mining operations.   Water  was  applied  to
haulage roads as necessary to prevent any dust problem.

    The area  of  potential  concern regarding radioactivity emissions was  radon
emanation from the surface  of the ore body  and overburden  piles.   Some  radon
is probably released  during blasting, but the ore  is  generally  quite coarse so
that  release  is minimal.   Activated charcoal  canisters  were  emplaced on  the
ore body, exposed faces of overburden, spoils piles,  and undisturbed  soil.


RESULTS


    Radon emanation rates measured  are shown in Table 1.   The  average  observed
rate  of  45  ± 15  pCi/mz-min from the ore body surface  is twice  the  observed
background rate of 22  * 11.   The  exposed surface  of  the ore body  is  less  than
that of both the overburden  and spoils  area.  The  average radon  emanation  rate
for the  entire developed pit  area of  about  20 pCi/m2_min  is  about  equal  to
the background rate for the area.

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                  TABLE 1.  BAUXITE PIT RADON EMANATION RATES
          Location
 Top of ore  body
 Top of ore  body
 Top of ore  body
                                   Average
Radon Emanation Rate
   (pCi7nr-nrin)a
         35
         62
         39
         45 ± 15b
 Top  of overburden - topsoil removed
 Overburden sidewall, 5 ft. below top
 Overburden sluffage berm, midway
   between surface and top of ore
                                   Average
          5.9
         13

          2.6
         7.2 ± 5.3
 Spoils area
 Spoils area
                                   Average
          4.9
         12
          8.5  ±  5.0
Pit background, undisturbed soil
Pit background, undisturbed soil
Pit background, undisturbed soil
Pit background, undisturbed soil
                                   Average
         27
          9.6
         16
         35
         22 ± 11
a) Picocuries (10~   curies) per square meter per minute.
b) Uncertainties of averages are standard deviation about  the mean.

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                                  SECTION 4


                           ALUMINA REDUCTION PLANT
PROCESS DESCRIPTION


    The  alumina  reduction  plant surveyed  used  a modified  "American  Bayer"
process to  recover  alumina (aluminum oxide)  from bauxite  ore.   Red mud,  the
waste material resulting from this process,  is further treated in a lime-sinter
process to remove sodium aluminum silicate  in the form of  pure  chemical  grade
alumina hydrates.  The final waste product is referred to as brown mud.

    Imported  South  American  ore and  domestic ore  are  blended  and  used  as
described above.   Imported Jamaican ore is  used separately  and  is treated only
by the  Bayer  process.   In the  Bayer  process ore  is  wet ground  in  rod  mills.
The  resulting slurry   passes  through  a  digestion   process  to  dissolve  the
alumina  in  caustic  liquor  which  is  separated  from  the  red  mud.   Alumina
trih^drate  is  precipitated  from the liquor, washed,  filtered,  and calcined at
1150,C  (2100°F) in rotary kilns to  produce  alumina, which may be shipped as is
or  may receive  further chemical   processing  for metallurgical   and  chemical
alumina uses.

    Red  mud  from the  Bayer  process  is  filtered   and' reslurried  with  the
addition of limestone and soda ash, then  is ball  milled.   The milled slurry is
sintered at 1260°C (2300°F) in rotary kilns.   Sinter  is ball  milled with water
to dissolve sodium  aluminate  formed during sintering.   After purification the
sodium  aluminate liquor is  routed  to precipitators  for recovery  of  chemical
grade hydrates.

    Radon present  in  the  ore is  presumed to  be lost to  the  atmosphere  during
the milling and  digestion  processes.   No single  source  of  emission  exists to
sample  such emissions.   Radon concentrations were measured  in  the exhausts of
the  Bayer  process, alumina  hydrate vacuum  filter,  rotary  kiln, and red mud
vacuum  filter.  Also radon was measured in  exhausts from the  lime-soda process,
lime  and  sinter  kilns, and  in  natural  gas  fuel  to  alumina  and  sinter  kilns.
Radon  emanation  from the brown  mud tailings  area was measured  with  charcoal
canisters.

    TSP  and  size-fractionated   particulate samples  were  collected from the
alumina kiln  electrostatic  precipitator  inlet and exhaust and from the red mud
kiln  exhaust.

    Process samples  included  domestic ore  from the  mine pit surveyed, blended
bauxite, alumina kiln feed, alumina product,  chemically treated  alumina product

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                                       TABLE  2.   RADIOACTIVITY  IN ALUMINA PLANT  PROCESS SAMPLES
                                                                     Radioactivity Concentrations  (pd/g)a
co
Sample
Bauxite Ore
Blended Bauxite
Alumina Ki In Feed
Alumina Product
RC-64 Alumina
Red Mud Filter Cake
Prepared Sinter Mud
Sinter
Brown Mudb
U-238
6.8
4.0
0.05
0.28
0.31
7.5
4.8
6.4
5.5
± 0.7
* 0.5
± 0.03
± 0.10
* 0.09
* 1.2
* 0.5
* 0.8
* 0.4
U-234
6.9
4.0
0.07
0.28
0.35
7.5
4.7
6.6
5.6
± 0.7
± 0.5
± 0.03
± 0.10
* 0.10
* 1.2
* 0.5
± 0.9
± 0.5
Th-230
6.4 ±
3.5 ±
<0.
<1
1.1
0.3
05

<0.6
5.1 *
4.2 *
6.5 *
8.0 ±
1.3
1.1
1.6
2.7
Ra-226
7.4
4.4
0.08
0.23
0.19
6.5
3.9
3.9
5.6
± 2.2
± 1.3
± 0.05
± 0.07
* 0.06
* 2.0
* 1.2
* 1.2
* 1.2
Pb-210
9.1
5.3
0.20
<]
<]
7.6
6.8
3.6
5.7
± 1.1
* 0.4
± 0.15
L.4
..3
± 0.4
* 0.4
± 0.4
± 0.8
Po-210
10.0 ± 1
4.2 ± 0.5
0.00 ± 0.20
<0.6
<0.6
7.7 ± 1.7
4.6 ± 0.5
3.2 ± 1.2
5.4 ± 0.7
	 Th
5.5
5.2
<0
<0
<0
5.0
5.0
9.2
12.5
-232
± 1.0
* 1.2
.05
.2
.2
* 1.5
± 1.3
± 2.1
± 4
Th-228
5.5 ± 1.0
5.6 ± 1.2
<0.05
<0.2
<0.2
6.3 * 1.5
5.5 ± 1.4
8.6 * 2.0
12.5 ± 4
        a) Picocuries  (10-1? curies) per gram plus  or minus twice the standard deviation based on counting statistics.
        b) The results are derived from duplicate samples.

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 (RC-64),  red  mud filter  cake,  prepared  sinter  mud,  sinter,  and  brown  mud
 tailings.
 RESULTS
    As  shown  in Table 2, the bauxite ore  was elevated in both  uranium-238  and
 thorium-232  with  concentrations  of  6.8  and  5.5  pCi/g.    The  addition   of
 imported  ore  reduced  the  concentration of  uranium to 4.0  pCi/g.  Removal  of
 alumina,  which contained  only 0.05  pCi/g of  uranium-238 and  less than 0.05
 pCi/g  of  thorium-232 resulted  in increasing  the concentrations  in  red mud.
 The uranium  and thorium concentrations  were again diluted  by the  addition  of
 lime  and  soda  ash to about  5  pCi/g.   The first fractionation of radioactivity
 occurred  in  the  sinter  kiln where  lead-210 and  polonium-210  were reduced  to
 about  half the concentration  of  the precursors.   The brown mud  lake  tailings
 results,  collected  from  the vicinity of the  charcoal  canisters,  shows  that  the
 lead-210  to be in approximate equilibrium with  its precursors  and polonium-210
 to  be  in  equilibrium with  lead-210.   Lead-210  in the  other process  samples
 appears to be  biased high, relative  to  uranium  and the  same  bias  probably
 applies  here   as  well.   Because  of  the  age  of  the   tailings  sample  the
 polonium-210 would  have  grown  to some higher degree of equilibrium than in  the
 sinter  material.

    The  low   radioactivity of   alumina  is  reflected  in   the  radioactivity
 emissions from the alumina  kilns  (Table 3).  Even though kiln  4  was  found  to
 be  emitting  about  20  times  as much  mass  as  usual,   probably  due  to  an
 inoperative electrostatic  precipitator,  the estimated annual  release  for  the
 four  kilns operating  during the  survey was  0.068 mCi/y  for  uranium-238  and
 -234 and <0.055 mCi/y for  radium-226.


 	TABLE  3.  ALUMINA  PLANT  PARTICULATE  RADIOACTIVITY EMISSION RATES
Source
Hood System 1
Hood System 3
Stacks'5
U-238
<0.7
<2.0
<6.0
U-234
<1.0
<0.7
<4.0
Th-230
<2.0
<2.0
<3.0
Ra-226
<0.4
<0.3
<2.0
Pb-210
8.1
7.8
32.0
Po-210
<5.0
7.5
<27
Th-232
<2
a
<6
Th-22!i
<2
<1
<6
a) Estimated from Method 5 contractor results
b) Four stack total
    Emissions  of   radionuclides   from  the  red  mud  sinter  kiln  were  below
measurable  concentrations  except  for  lead-210  and  polonium-210.   The  high
temperatures  caused a large  fraction  of those to  be  volatilized, as  shown by
the  process sample results.   Emissions  of  the  two nuclides were  essentially
equal  with  7.8 mCi/yr for lead-210 and 9.3 mCi/yr for polonium-210.

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TABLE 4.  ALUMINA PLANT AMBIENT AND STACK RADON-222 MEASUREMENTS
          Collected
Concentrations (nCI/m3)3      Annual
Source
Ambient Air


Alumina
Alumina

Time
1252-1650
0955-1417
0941-1332
1319-1618
1009-1358
0956-1301
Date
11/13/79
11/14/795
11/15/79
11/13/79
ll/14/79b
11/15/79
Gross
0.13
0.16
0.45
0.07
0.25
0.29
Net
± 0
± 0
± 0
± 0
± 0.
± 0,
.04
.03
.08
.03
.04
.07
Source Average
Alumina


1315-1606
0925-1230
1013-1332
11/13/79
11/14/79
ll/15/79b
0.49
0.50
0.52
± 0.
± 0.
± 0.
,07
06
05
Source Average
Alumina


1314-1621
1337-1345
1010-1322
ll/13/79b
11/14/79
11/15/79
0.53
0.47
0.55
± 0.
± 0.
± 0.
05
06
11
Source Average

Red Mud

Total for
1145-1611
0941-1338
4 Kilns
11/13/79
11/14/795
0943-11/15/79

1.5
2.1
1.5

± 0.
± 0.
± 0.

1
1
1






-0.06
0.
.09
-0.16
-0.04
0.
0.
0.
0.
0.
0.
0.
0.

1.
1.
1.
.36
,34
07
,26
40
31
10
27

4
9
0



Emissions(Ci/Yr)



± 0.05
± 0.
± 0,
,05
.11
± 0.18
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.
± 0.

± 0.
± 0.
± 0.
,08
08
09
16 0.074
06
08
14
15 0.067
0.27
1
1
1
     Source Average
               1.4  ±0.5
0.019
                              10

-------
TABLE 4. (Continued)

                 Collected
             Concentrations  (nCi/nrJa      Annual
Source
Lime Kiln
Red Mud


Time
1216-1552
1228-1606
0930-1331
0930-1320
Date
11/13/79
ll/13/79b
11/14/79
11/15/79
Gross
0
1
.03
.2
1/3
1
.7
± 0
± 0
± 0
± 0
.01
.1
.1
.1
Source Average
-0
1
1
1
1
Net
.13
.1
.1
.2
.1
± 0.
± 0.
± 0.
± 0.
* 0.
Emi
04
1
1
1
1
ssions(Ci/Yr)




0.39
Total for 5 kilns
                                            2.0
Natural Gas  1515
11/15/79'
5.8 ± 0.1
a) Nanocuries (10~9 curies) per dry, standard cubic meter (20*C, 760 mm
   mercury pressure) plus or minus twice the standard deviation based either on
   counting statistics or in the case of source averages on sample variance..

b) The results are derived from duplicate samples.
                                      11

-------
    Two  size-fractionated  particulate samples were collected  from  the alumina
kiln 8 stack and  from  the  sinter kiln stack.   Radioactivity was below detect-
able  levels on the  size fractions  collected from the  alumina kiln,  but  the
mass distribution by aerodynamic particle  size for  the  two  samples  showed  a
geometric  mean  diameter (GMD) of  2.2 urn with  a geometric  standard  deviation
(GSD) of 2.4 on one sample and a GMD of 3.3 um  with a GSD  of 2.8 on the other.
The sinter kiln  aerodynamic  size distribution  was a  GMD  of 2.3 um and  GSD of
3.9 on one sample and a GMD  of  2.4  vm and GSD of  3.8 on  the other.   Radio-
activity levels on the  first  sinter  kiln  sample, analyzed  by individual stages
were below detectable.   Compositing  of stages  from the second sample resulted
in  detectable  quantities   of  polonium-210   being   measured.    Polonium-210
activity mean aerodynamic diameter (AMAD) was 5.5  ym  with  a GSD of 8.1.   This
result was the opposite of the expected AMAD of less than 1 um and low GSD.

    The  highest  average radon concentration  in a  stack   was  measured on  the
discharge  from  the  red mud  vacuum  filter  at  1.4   ±  0.5  nCi/m3  (Table  4).
With a low exhaust flow  rate  it  emitted  only 0.019 Ci/y.   The largest process
source of  radon-222  was the  red  mud sinter kiln with  a   single kiln  emission
rate of  0.39  Ci/y.   Total  for   the  five  kilns operating  at  that  time  was
2.0 Ci/y.   The  alumina  kiln  emissions  averaged .074  Ci/y  from kiln  4  and
.067 Ci/y  from kiln  8 with an average for  four operating kilns of  .27  Ci/y.
It is probable, considering the  low  radioactivity  of  alumina  and the  negative
result  for the  discharge rate of radon-222  from  the  alumina vacuum  filter,
that the alumina  kiln  emission was  due to radon-222  in  the natural gas  fuel.
Natural  gas was  found to have  a radon-222  concentration of  5.8 ± 0.1 nCi/m3.
                                                                            mud
     Charcoal  canister  radon-222  emanation  measurements  from  the  brown
 tailings  lake and an undisturbed area nearby are shown  in  Table 5.  The over-
 lapping  confidence intervals rule out any finding  of a significant  difference
 between  the emanation rate averages.


               TABLE 5.   BROWN MUD TAILINGS RADON EMANATION RATES

                          Emanation Rates  (pCi/m2-min)a
                          Tailings           Background
                            67              —tr—
                            33                  40
                            43                  26
                            48                   5
                            15
                            11
       ,                     19                   ^
Average0                    34 ± 20             23 ± 14


a) Picocuries (10-12 curies) per square meter per minute.
b) Average plus or minus the standard deviation about the mean.
                                     12

-------
                                   SECTION 5


                           ALUMINUM REDUCTION PLANT
PROCESS DESCRIPTION


    Aluminum  metal  is  produced  from  alumina  by  the  "Hall"  electrolytic
reduction process.  An electric  current  passed through a large  shallow  pot  of
cryolite  (Na3AlF6) raises  the  temperature  to  about  975*C,  which  maintains
the  cryolite  in  a  molten  state.   Alumina,  in  a  fine  powder  form,  is
periodically added to the surface  of  the molten cryolite which  serves  as both
an  electrolyte  and  solvent  for   the   alumina.   Small  amounts  of  aluminum
fluoride are added to maintain the optimum  level  of fluoride which  is  lost  in
the pot emissions.

    A  carbon  lining  in the  pot  serves   as  the cathode  and  a carbon  anode  is
immersed in  the  molten cryolite from  above the pot.   Two  forms of  anode are
used,  either prebaked  anodes consisting of  large  blocks of  petroleum  coke  or
an asphalt pitch  binder  which is  baked  to  a hard  carbon.  These  are replaced
as the anodes are  consumed  by  the oxygen  released  in the  alumina  reduction
process.   Horizontal  Stud Soderberg  (HSS)   anodes  use  a process  in which  a
coke-pitch mixture is  placed in  a  hopper  atop  the  pot.   Horizontal  metal
studs, which  also serve as  the  electrical   connection,  are inserted  into the
mass  above the molten  surface.    The  high   temperature of the  pot  bakes the
mixture  into  a   solid  carbon  mass  as  it   nears  the  pot.    The  studs  are
periodically withdrawn and inserted higher to  allow the anode to descend as  it
is consumed.

    Several processes, including materials handling and electrode preparation,
produce atmospheric emissions of  vapors  and particulates which were  not con-
sidered  to  be  significant  sources  of  radioactivity.   The  only sources  of
concern to this survey were  the  controlled  and uncontrolled emissions from the
reduction  pots.   Reduction  pot  operation is essentially an  open  process  but
hoods  are  employed to control emissions.   Several  techniques for  hooding the
pots  were  being   evaluated to determine  the optimum  for each  pot  type   Wet
scrubbers treat the fumes collected from groups of 40  pots  before discharging
the exhaust to the atmosphere through 36 m stacks.  Eighty  pots  in each of two
buildings comprise the pot line.  Each  building, approximately  350  m long,  is
ventilated by natural circulation  through roof ridgeline monitors.   The combi-
nations  of winds  and  thermal  rise  from  the hot  pots produces  a  reported
ventilation rate of one air change every minute or two.
                                      13

-------
                          TABLE  6.   RADIOACTIVITY ALUMINUM  REDUCTION PLANT  PROCESS  SAMPLES
                                                             Radioactivity Concentrations  (pCi/q)a
Sample
Alumina
Alumina
Average
Aluminum Fluoride
Aluminum Fluoride
Average
Cryolite
Cryolite
Average
Aluminum
Aluminum
Average
U-238
0.08
0.12
0.10
0.13
0.08
0.11
0.11

0.11
0.04
0.15
0.10
* 0.05
± 0.06
± 0.04
± 0.05
* 0.05
* 0.04
* 0.06

* 0.06
* 0.03
± 0.06
* 0.03
0
0
0
0
0
0
0
0
0
0,
0
0
U 234
.11
.13
.12
.26
.13
.20
.12
.09
.11
.09
.10
.10
* 0.06
± 0.06
± 0.04
± 0.08
* 0.06
± 0.05
* 0.06
* 0.05
* 0.04
± 0.05
* 0.05
± 0.04
Th-230
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
Ra-226
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
20 ±
14 *
17 *
12 ±
12 ±
12 ±
15 ±
12 *
14 *
15 ±
14 ±
15 ±
0.06
0.04
0.04
0.04
0.04
0.03
0.04
0.04
0.03
0.04
0.04
0.03
Pb 210
<1 .4
<1.6
<1.5
<1.5
<1 .4
<1.5
<1.6
<1 .6
<1 .6
<1.5
<1 .6
<1 .6
Po-21i
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
<0.7
Th-232
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
>0.2
Th-228
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
>0.2
>0.2
<0.2
<0.2
<0.2
>0.2
a)  Picocuries  (10    curies) per gram plus or minus twice the standard deviation based on counting statistics.
b)  Picocuries  per gram plus or minus the standard deviation based on sample variance.

-------
 RESULTS

     Two exhaust  stacks  were sampled.  One  handled  emissions from  40  HSS pots
 and one handled  emissions  from 20 HSS pots  and 20 prebake  pots.   High volume
 air samplers collected  participate emissions from the  roof  monitors over each
 building.   Radon was measured in the stack emissions and at the roof monitors.

     The company  provided  samples  of alumina, aluminum  fluoride,  cryolite, and
 aluminum.    All  materials   exhibited  similar   radioactivity  concentrations,
 averaging  0.13  pCi/g  for those  uranium  chain  nuclides which were present in
 detectable quantities (Table 6).

     Radon-222 in stack  emissions  and building ventilation air was  found to be
 indistinguishable from ambient levels.

     Only  lead-210  and  polonium-210  were  collected  from  the hooding system
 exhaust stacks  in  measurable quantity.   Lead-210 emissions  averaged 8.1 mCi/y
 in hooding system  1  and 7.8  mCi/y in hooding  system 3  (Table 7).  The total
 from  the  four  stacks  was   32  mCi/y.   Polonium-210  averaged   <6 mCi/y from
 hooding system 1 and 7.5 from hooding system 3,  with  a four-stack total of  27
 mCi/y.  The  total  emissions  of the  other  particulate  radionuclides   averaqed
 <8 mCi/y.


 	TABLE 7.  ALUMINUM REDUCTION PLANT EMISSION RATE
Source U-238 U-234
Alumina 0.068 0.058
Kilnsb
Red Mud
Sinter Kilnsc
Th-230 Ra-226 Pb-210
<0.24 <0.055 <0.34
7.8
Po-210
<0.14
9.3
Th-232 Th-22t'
<0.05 <0.05

a) Estimate from Method 5 contractor results.
b) Total emissions from four kilns
c) Total emissions from six kilns


     Lead-210 and  polonium-210 were collected  in measurable  quantities  on the
 high volume  filter samples collected  from the  roof  monitor of  the  north pot
 room.  No  measurable quantities of  any radionuclides were  collected from the
 south building  roof  monitor.   Roof access  limited sampling  to  the south side
 of the north building roof monitor and  to  the  north side of the south building
 roof monitor.   Wind  directions  may  have  influenced  the  flow  of  particulates
 through  the  monitors,  but mass  loading on  the  south  building  samples were
 higher than  on the  north  building  samples.   Concentrations measured  in the
 north  building  roof  monitor  were:  lead-210,  8  ± 220  fCi/m3;  polonium-210,
 200  *  250  fCi/iTH.    The  concentrations   measured  the  following  day  were'
 lead-210,  60  * 130  fCi/nP;  polonium-210,  550  ±  210 fCi/m3.   The  relatively
 high  uncertainties associated  with   the net  concentrations  result  from the
 relatively large and variable blank filter analyses.  These compare to ambient
                                       15

-------
concentrations  measured   near   the  plant  of:  lead-210,  16   ±   6  fCi/m3;
polonium-210, 17 ± 6 fCi/m3.  The average lead-210 emission concentration of
16 ±  6 fCi/m3;  polonium-210,  17 ± 6 fCi/m3.   The  average lead-210 emission
concentration of  33 ±  26  fCi/m3 did not  differ  significantly  from ambient.
The average  polonium-210  concentration of  380  * 180 was  significantly  higher
than ambient.  Assuming one air change every 2  minutes  the annual emissions of
polonium-210 from the building,  based on  the two samples, would be 17 mCi.
                                     16

-------
                                  SECTION 6


                       UNDERGROUND COPPER MINE  AND MILL
PROCESS DESCRIPTION

    Selected for this survey was an underground copper-iron-zinc-sulfide mine.
The Mine  Safety and  Health  Administration (MSHA)  had  reported average  radon
daughter WL* measurements of 0.087 with a maximum of 0.21.   (personal  communi-
cation with  Aurel  Goodwin,  MSHA).  The  ore runs less  than  1  percent  copper,
less than 1  percent  zinc, 20  percent  iron,  and 25 percent sulfur.  A mill  and
flotation plant  produces concentrates of  the three  sulfides and disposes  of
about 50 percent of the ore as tailings.

    The mine operates three shifts per day,  5 days per week.   Blasting of  the
drilled ore is done at about  1500 hours  each  day.   An exhaust fan  housed above
a  vertical  shaft  into  the  mine  provides  a  ventilation rate of  2,660 m3-min
through  the mine.   Air  discharge  is horizontal  at  ground  level  through  a
1.76-m diameter outlet.

    Ore from the mine surveyed, from  another  adjacent underground  mine, and an
adjacent  open  pit  mine  is  processed in  the  flotation  plant.   Primary  and
secondary crushers  reduce the ore to less than  2-inch  size before  it enters
the ball  mills of the  flotation  plant.   A rotoclone wet  scrubber  cleans  the
emissions from the crushers.   The scrubber discharges  horizontally  about  4 m
above  ground  at  484 m3-min.   The mill  produces  about  15,000  tons  each  of
copper and zinc and 300,000 tons of iron as sulfides per year.

    As shown in  Table 8,  the  uranium  decay chain nuclides were at or  slightly
above the average  concentrations  found in  crystal rock.  The ore concentration
averaged about 1 pCi/g.

    As  would  be  expected  in  a  process  which  is  designed  to  selectively
concentrate  metals,   the  concentrates   generally   have   lower  radionuclide
concentrations than  the  ore or  tailings.  The zinc concentrating process seems
to  be the  most  discriminating  with  concentrations averaging  40  percent  of
those in ore.
*  Working  Level  (WL)  is defined  as  any  combination  of  short  lived radon
daughter  products  in one  liter  of  air  that  will  result  in  the  ultimate
emission  of  1.3  x  lO^   Mev  of  potential  alpha  energy  (U.S.  Public  Health
Service publication No. 494,  1957).
                                      17

-------
                      TABLE 8.    UNDERGROUND  COPPER  MINE AND MILL PROCESS  SAMPLE RADIOACTIVITY
Sample
U-238
U-234
Th-230
                        Radioactivity Concentrations  (pCi/g)a
                            Ra-226         Pb-210         Po-210
Th-232
Th-228
Ore

Average
Copper
Concentrate
Average
Zinc
Concentrate
Average
Iron
Concentrate
Average
Tailings

Average
0.79 * 0.14
0.78 ± 0.19
0.79 ± 0.20
0.79 ± 0.10
0.63 ± 0.14
0.59 ± 0.15
0.73 ± 0.17
0.65 ± 0.09
0.28 ± 0.07
0.29 ± 0.07
0.37 * 0.09
0.31 ± 0.04
0.37 ± 0.11
0.42 * 0.10
0.52 * 0.12
0.44 * 0.06
0.86 * 0.16
0.88 * 0.18
0.71 ± 0.12
0.82 ± 0.09
0.72 * 0.13
0.93 * 0.22
0.80 ± 0.20
0.82 ± 0.11
0.63 ± 0.15
0.57 ± 0.16
0.78 ± 0.18
0.66 ± 0.09
0.33 ± 0.08
0.36 * 0.08
0.41 * 0.10
0.37 * 0.05
0.38 ± 0.11
0.47 * 0.10
0.51 ± 0.12
0.45 * 0.06
0.79 * 0.15
0.84 ± 0.16
0.77 ± 0.13
0.80 * 0.08
0.92 * 0.60
1.6 ± 0.4
1.5 ±0.9
1.3 * 0.4
0.73 * 0.21
0.87 ± 0.29
0.98 ± 0.34
0.86 ± 0.16
0.52 * 0.24
0.42 * 0.18
0.34 ± 0.18
0.43 ± 0.12
0.44 * 0.30
0.72 ± 0.1S
0.94 * 0.26
0.70 * 0.15
0.86 * 0.22
1.1 * 0.2
1.3 ± 0.2
1.1 * 0.1
0.33 ± 0.20
1.4 ± 0.4
0.69 ± 0.21
0.81 * 0.16
0.84 * 0.25
0.99 * 0.30
0.77 * 0.23
0.87 * 0.15
0.17 ± 0.05
0.44 ± 0.13
0.40 ± 0.12
0.34 * 0.06
0.10 ± 0.06
0.86 * 0.26
0.52 ± 0.16
0.49 ± 0.10
0.76 ± 0.23
1.4 ± 0.4
0.41 * 0.12
0.86 * 0.16
0.80 * 0.43
2.1 * 2.0
1.1 * 0.4
1.3 ± 0.7
0.84 ± 0.64
0.41 ± 0.29
0.44 * 0.27
0.56 * 0.25
0.45 * 0.22
0.52 ± 0.32
0.67 ± 0.28
0.55 ± 0.16
0.8 ± 1.8
0.60 ± 0.36
0.86 ± 0.75
0.75 * 0.66
1.3 ± 0.7
1.2 ± 0.9
0.97 ± 0.58
1.2 * 0.4
0.73 ± 0.39
2.0 * 1.9
t.O * 0.4
1.2 * 0.7
0.76 ± 0.58
0.41 ± 0.29
0.41 ± 0.25
0.53 * 0.23
0.41 ± 0.20
0.48 * 0.29
0.62 * 0.26
0.50 * 0.15
0.8 ± 1.6
0.55 ± 0.33
0.80 ± 0.70
0.72 ± 0.59
1.2 ± 0.7
1.1 * 0.8
0.90 * 0.54
1.1 * 0.4
0.53 ± 0.46
0.46 * 0.17
0.88 ± 0.61
0.62 * 0.26
0.04 ± 0.04
0.14 * 0.09
0.04 * 0.05
0.07 * 0.04
0.10 ± 0.09
-0.01 * 0.03
-0.18 ± 0.12
-0.03 ± 0.05
0.10 ± 0.12
0.09 ± 0.05
0.37 ± 0.14
0.19 ± 0.06
0.19 ± 0.8
0.23 ± 0.09
0.29 * 0.06
0.24 * 0.27
0.36 * 0.31
0.44 ± 0.16
0.88 ± 0.61
0.56 ± 0.23
0.04 ± 0.04
0.13 * 0.09
0.04 ± 0.05
0.07 * 0.04
0.07 * 0.06
0.18 * 0.09
-0.18 * 0.12
0.02 * 0.05
0.10 * 0.12
0.09 * 0.05
0.37 * 0.14
0.19 ± 0.06
0.19 * 0.08
0.22 ± 0.09
0.25 ± 0.06
0.22 * 0.04
 a)  Picocuries  (10    curies) per gram plus or minus twice the standard deviation based on counting statistics.
 b)  Picocuries  per gram plus or minus the standard deviation based  on sample  variance.

-------
      TABLE 9.  UNDERGROUND COPPER MINE AND MILL RADON-222 MEASUREMENTS
                 Collected
                      Concentrations  (nCi/m  )a
Source
Time
Date
Gross
Net
    Annual
Emissions(Ci/Yr)
Ambient Air  1000-1400  1/30/79
             1600-1835  1/30/79
             2300-0215  1/31-2/01
             0940-1200  2/01/79
             1202-1350  2/01/79
                       0.64 ± 0.28
                       0.40 ± 0.16
                       0.14 ± 0.20
                      -0.01 * 0.14
                      -0.03 ± 0.20
Crusher      1625-1720  1/30/79
             1500-1700  2/01/791
                       0.26 ± 0.14
                       0.02 ± 0.13
Mine Outlet  1230-1500  1/30/79
             1530-1800  1/30/79
             2305-0235  1/31-2/01
             0950-1210  2/01/79
             1212-1400  2/01/79
             1410-1630  2/01/79
             Mine Outlet Average
4
6
4
5
2
4
.6
.0
.0
.4
.8
.8
±
±
±
±
±
±
0
0
0
0
0
0
.2
.4
.2
.4
.4
.4
4
5
3
5
2
4
.0
.6
.9
.4
.8
.8
±
±
±
±
±
±
0
0
0
0
0
0
.3
.4
.3
.4
.4
.4
                                      4.4 * 1.1
                                          6.2
Crusher      1626-1720  1/30/79       0.68 ± 0.16
             1500-1700  2/01/79       1.8  ± 0.2
             Crusher Exhaust Average
                                     0.42 ± 0.23
                                     1.8  * 0.3
                                     1.1  ± 1.0
                                          0.28
 a)  Nanocuries  (10~9 curies) per cubic meter plus or minus twice the standard
    deviation based on counting for individual sample results; plus or minus the
    standard deviation of the mean for source averages.
 b)  The results are derived from duplicate samples.
                                       19

-------
RESULTS


    Ambient  radon  concentrations  measured  near the  facility  and  discharges
from  the  mine  and  the  mill  crusher are  shown  in Table 9.   During  the latter
part of the survey, snow-cover apparently reduced the ambient radon concentra-
tion by reducing radon emanation from soil.  Radon concentrations in mine
exhaust  air  averaged 4.4  ± 1.0  nCi/m3  with an  annual estimated emission  of
6.2 Curies.  Some disagreement exists between  the MSHA WL  measurements and EPA
radon  measurements  in  the  mine  exhaust.   The  MSHA  reported  an  average  of
0.087   WL would require  a radon concentration of 8.7  nCi/m3  at 100 percent
equilibrium.   One  or  both  sets  of  measurements  may  be  biased,  or  mine
operations may have changed.

    Radon  in  the  crusher  exhaust  averaged  1.1  ±  1.0 nCi/m3  above  ambient
levels, with a net annual emission of 0.28 curies.

    Radioactivity in  suspended  particulates  in the crusher  exhaust  were  not
significantly greater than zero.  Annual  emissions  of  individual  uranium chain
radionuclides were each less than 6
                                     20

-------
                                  SECTION 7



                    OPEN PIT COPPER MINE AND CONCENTRATOR


PROCESS DESCRIPTION


    A  large  open-pit copper  mine and  the associated  mill  and  concentrating
plant were surveyed to  further characterize the copper  industry  radioactivity
emissions.  At the time of the survey the pit covered an  area of  about 2250 by
1700 m  and  had reached  a  depth of about  550 m.   The  mine  operators removed
about 158,000 MT of material per day,  of which about 45,300 MT were ore.

    Ore and  rock  were blasted  each  day at noon.   Ore  trucks  operated around
the clock hauling  ore to the crusher or  leach  screening pile  and  rock to the
waste  dump.   Ore  which graded  0.24  percent copper or  higher was  sent to the
crusher.  That which  graded 0.10 to 0.23  percent  went  to  the leach  screening
pile where copper was chemically  leached from the  ore.   Rock grading  less than
0.10 percent  was  waste rock.   A baghouse controlled particulate emissions at
the crusher  and  truck hopper.   Vibrating grizzly  feeders  screened the crushed
ore at  4  inches.   Oversize is  sent to  a gyratory  primary  crusher.   Undersize
and crushed ore were moved  by conveyor  belt to  an  open  coarse ore  stockpile or
to six  coarse  ore  storage  bins.  "Chem-Jet" sprays were  used to suppress dust
formation after the grizzlies,  at the entrance to  the  primary crusher, and at
the crusher  discharge.   A  baghouse  identical  to  the one on  the truck hopper
collected dust from all primary crusher operations.

    "Chem-Jet" sprays and  hoods connected  to  the baghouse controlled  dust from
transfer  points on  the  conveyor from the  primary  crusher to  storage.   Similar
controls  collected dust  from  transfer  and discharge  points  on the  conveyor
system  from coarse ore storage  to six surge bins at the  secondary crusher.

    Vibrating  screens separated  ore  from  the  surge bins  at  1  inch   (2.5  cm)
with undersize going  directly  to 12 fine ore storage bins at  the  concentrator
building.   Oversize  was  crushed  to  3/4-inch  (2-cm)  size  in three  gyratory
crushers  and sent to fine ore storage.   Transfer points were hooded and  the
dust was  collected by  six Ducon wet  scrubbers.  Chem-Jet  spray  systems  also
controlled dust at belt  transfer  points.

    A  system of  belts carried ore from the 12  fine ore  bins to  six rod mills.
Twelve ball  mills,  operating in a closed  circuit, further ground  the ore from
the rod mills.  A cyclone  and  flotation  section recovered mineral  values from
the pulverized ore.   Sand tailings were thickened and  pumped  4.8  km  (3 miles)
to  the tailings  pond.  Wet concentrates  were carried by  rail to  the smelter.
Seven  Ducon  scrubbers collected dust  from  the fine ore  bins area.  Roof fans,  a


                                       21

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  wall  fan,  and  natural  ventilation provided  ventilation  for  the  concentrator
  building.   The entire  process of  milling,   flotation,  and  concentration  was
  carried on  under  one roof.  The process  was  wet and  generated  no  appreciable
  airborne particulates.   Water  decanted from the tailings pond was  recvcled  tn
  be used as flotation spray water.


  SAMPLING POINTS


      Ambient suspended  particulate  and  radon  samples  were  collected  at  three
  locations  around  the  facility.  One ambient  site,  identified as Mountain Con
  was about 0.8  km  northwest of  the  mine pit,  2.9  km northwest of the concen-
  trator.   The second site, Alpine, was  about  270  m  southeast  of the concentrator
  building and 1.9 km southeast of the mine center.  The third  site, Kaw Avenue
  ?JSi,     1.1  u*   ,km southwest of ^e  mine pit  and  concentrator.   Continuous
  24-hour  high volume particulate samples were collected simultaneously with all
  plant  emission radon samples.   Sufficient samples  were collected to assure at
  least  two  samples from each  4-hour  period of the  day.  Measurements  of  radon
  emanation  from  the surface  were made  in  the  mine  pit and  from  surrounding
  areas  by charcoal  canisters.

  +h  ISP  ,an?  Slze-fractionated particulate  emission  samples  were collected from
  the truck hopper and  primary crusher exhausts.  Company data and  visual  exami-
  nation indicated that other possible controlled  sources would be insignificant
  compared to those  two.

     Emissions  of radon were  measured  from the  truck  hopper,  primary  crusher
  secondary crusher, and concentrator  handling exhausts.

     Size-fractionated suspended particulate samples were collected  adjacent  to
  the coarse ore storage pile and  the  leach screening pile.


 SAMPLE RESULTS



    TRd,ii0antlVrty concentrations in  ore, concentrates,  and  tailings are  shown
  J   *  Jf       Concentrations  in ore of  uranium and  thorium chain nuclides are
 J««J-  5T  *JjeLthe  avera9e ejected  in crustal rock.  As  in  the mill process
 JSSfnfSS/lS *5* ^!r2rou"d  C0pper mlne» tne  radioactivity  levels in
T KiRa1Sn  Concentrat1ons measured at  the  three ambient  stations  are shown in
 3 1?   u   "?ur]y average wind  directions  were evaluated to  determine  if the
station had been  upwind,  downwind,  or crosswind from  the open mine pit durina
each sampling  period.   In only  three cases was  it  determined that  a station
had  been  downwind.  Although  diurnal variations  are  quite evident,  with the
highest concentrations during the early morning hours and lowest concentrations

downwind 0VtheemTn°en:  "° '^  ""  °bSerVed "  *  r6SUlt °f be1ng  Upw1nd  or
                                      22

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                         TABLE  10.   OPEN  PIT  COPPER MINE AND CONCENTRATOR PROCESS  SAMPLE  RADIOACTIVITY
                                                                   Radioactivity Concentrations  (pCi/g)
ro
CO
         Sample
U-238
U-234
Th-230
Ra-226
Pb-210
Po-210
                                                                                   Th-232
                                                                                   Th-228
Ore-Primary Crusher

Ore- Secondary Crusher

Ore Average
Concentrate

Concentrate Average
Tailings


Tailings Average
2.4
2.0
2.2
2.0
2.2
1.1
1.7
1.4
1.5
1.7
1.7
1.6
± 0.3
* 0.4
± 0.5
± 0.3
± 0.3
* 0.3
* 0.4
* 0.3
* 0.3
* 0.3
* 0.3
± 0.2
2.2
1.9
2.2
1.4
1.9
1.2
1.6
1.4
1.5
1.5
1.7
1.6
± 0.3
* 0.4
± 0.5
± 0.2
± 0.3
* 0.3
* 0.3
* 0.2
± 0.3
* 0.3
± 0.3
* 0.2
3.6
6.7
3.8
2.4
4.1
2.0
3.4
2.7
3.2
4.3
2.3
3.3
± 0.9
* 1.7
± 1.4
± 0.8
± 0.8
± 0.8
± 1.1
* 0.7
* 1.4
± 1.5
± 0.9
* 0.8
0.92
1.5
0.42
0.72
0.89
0.14
0.93
0.54
1.0
1.6
1.0
1.2 *
* 0.28
± 0.4
± 0.13
* 0.21
± 0.12
* 0.04
* 0.28
* 0.14
* 0.3
* 0.4
± 0.3
t 0.2
7.2 ± 2.7
4.7 ± 1.5
2.6 ± 1.3
2.0 ± 1.3
4.1 * 0.9
<2.3
2.6 * 1.5
<2.5
2.1 * 1.4
<6.6
2.2 * 1.4
<3.6
6.3
5.0
3.5
3.3
4.5
<]
2.2
<1
2.0
2.0
2.8
2.3
± 1.6
± 1.5
* 1.3
* 1.3
± 0.9
..2
* 1.1
..7
* 1.1
± 1.1
* 1.2
* 0.7
2.5
4.2
3.5
2.0
3.1
1.3
0.82
1.1
3.7
4.2
1.2
3.0
± 0.7
± 1.2
± 1.0
± 0.7
* 0.6
± 0.6
* 0.46
± 0.4
± 1.6
± 1.4
* 0.6
* 0.7
3.5
4.5
3.8
1.5
3.3
0.94
1.0
0.97
4.9
4.2
1.1
3.4
± 1.2
* 1.4
* 1.2
± 0.6
± 0.7
± 0.40
± 0.4
± 0.3
± 1.5
* 1.4
* 0.4
* 0.7
        a) Picocuries (10~^ curies) per gram plus or minus  twice the standard deviation based on counting statistics.

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      TABLE 11.   AMBIENT STATION RADON-222  CONCENTRATIONS  -  OPEN PIT  COPPER MINE
 Date
 10/14/80
   Time
 1200-1500
 1600-1900
 2000-2300
           Radon-222 Concentration (nCi/m3)a
     Kaw Avenue              Alpine            Mt.  Con
                      0.53 ± 0.07 (U)b
                      0.21 ± 0.06 (C)        0.20 ±  0.06  (C)
                      0.30 ± 0.07 (C)        0.32 ±  0.06  (C)
0.63 ± 0.7  (C)D
 <0.07      (U)
0.28 ± 0.05 (U,D)
 10/15/80
 0300-0600
 1200-1500
 1600-1900
 1.1   ± 0.1   (U,C)
 0.44  ± 0.06  (U)
                     1.3  ± 0.1   (D,C)
                     0.22 ± 0.05  (C)
                     0.09 ± 0.05  (C)
                                                                    0.32  ±  0.05  (U,C)
                                                                    0.20  ±  0.05  (C)
 10/16/80   0700-1000    0.57 ±0.04  (NA)
           1200-1500
           1600-1900
             0.10 ± 0.04 (C)
             0.16 ± 0.05 (U)
                     0.69 ± 0.09
                     0.95 ± 0.09
                     0.82 ± 0.06 (NA)
                     0.12 ± 0.05 (U)
                     0.08 ± 0.03 (C)
                                                        0.55 ± 0.04
                                                        0.77 ± 0.11
                                                        0.66 ± 0.06 (NA)
                                          0.23 ± 0.06 (C)
10/17/80
0000-0300
1200-1500
0.81 ± 0.06 (C)
0.14 ± 0.02 (U)
                    1.2  ±0.1  (U)
                    0.19 ± 0.02 (C)
                                                                   0.83 ± 0.08 (D)
                                                                   0.28 ± 0.03 (C)
a) Nanocuries (10~9 curies) per cubic meter plus or minus twice the
   standard deviation based on counting statistics.
b) Upwind (U), downwind (D), or crosswind (C) from the open pit mine,
   based on hourly average wind observations at Mt. Con site.  NA = not
   available due to recorder failure.
                                        24

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  TABLE 12.  COPPER MINE CRUSHER AND CONCENTRATOR - RADON-222 MEASUREMENTS
Collected Concentrations (nCi/m )
Source
Primary


Time
1422-1706
0300-0600
1200-1500
Date Gross
10/14/80
10/15/80
10/17/80b
0
0
0
.62
.90
.66
± 0.
± 0.
* 0.
08
09
03
Primary Crusher Average
0
-0
0
0
Net
.46
.20
.46
.24
± 0.
± 0.
± 0.
* 0.
Annual
Emissions(Ci/Yr)
11
13
08
38



0.22
Secondary    1435-1752   10/14/80      0.45  ±0.08
             1225-1538   10/15/80      0.26  ± 0.07
             Secondary  Crusher Average
             Total for  seven stacks
                                       0.29  ± 0.11
                                       0.06  * 0.10
                                       0.18  ± 0.16
                              0.077
                              0.50
Truck
1630-1903  10/15/80
1154-1412  10/16/80
1514-1819  10/16/80b
Truck Hopper Average
0.36 ± 0.06
0.74 ± 0.06
0.35 ± 0.03
0.25 ± 0.08
0.63 ± 0.06
0.23 * 0.07
0.37 ± 0.23
                                                                    0.31
Concentrator 1106-1419  10/14/80°     1.1  ± 0.1
             1140-1505  10/15/806     0.45 ± 0.05
             1519-1825  10/15/80      0.25 * 0.06
             Concentrator Bldg. Ventilator Avg.
                                       0.57 ± 0.12
                                       0.16 ± 0.14
                                       0.16 ± 0.14
                                       0.30 ± 0.24
                              0.86
 a)  Nanocuries  (10~  curies) per cubic meter plus or minus twice the
    standard deviation based either on counting statistics or sample variance
    for  source  averages.
 b)  Derived from  duplicate  samples.
 c)  144-hour per  week operation.
                                      25

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     Radon  concentrations  and  emission  rates  determined  for  the  stacks  ™H
 building surveyed are given  in  Table 12.   Each  of the sources  showed  average
 radon  concentrations which  were above the ambient levels determined from  the
 ambient  stations.   The  maximum net  concentration observed  was 0 37  ±  0 23
 new  in  the truck  hopper exhaust.  The  maximum annual  emission  rate for  a
 single source was 0.86 Ci/y from the concentrator building.  Total radon
 emissions from the crusher  and  concentrator operations  was 1.9 Ci/y.

     Concentrations of  uranium-234 and uranium-238  in  stack emissions averaged
 0.2 pCi/rrP from the primary  crusher  and 0.09  pCi/m3 from  the  truck hopper
 These   compare  to  measured  ambient  concentrations   of  about  0 5   fCi/m3
 Annual  emissions measured from the primary crusher and truck hopper were  less
 than 1  mCi  (Table 13).


         TABLE 13.   AVERAGE ANNUAL EMISSIONS FROM AN OPEN PIT COPPER MINE
Source
Primary
Crusher
Truck Hopper
U-238
0.24
0.07
U-234
0.24
0.14
Th 230
<0.3
<0.3
Ra-226
0.11
0.07
Pb-210 Po-210 Th-232
0.89 <1 
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    Measurements of  radon emanation  rates  from the  surface of  the mine  and
surrounding areas are  summarized  in Table  15.   Several  canisters in the mine
were  lost  due  to  mining  activities,  but  those  that were  collected  show  an
increase in emanation  rates  as a function  of  depth.   This may be real  or  may
result from  infiltration of radon  from  the surrounding  air.   Radon would  be
expected  in  higher  concentrations near  the  bottom  of  such  a  pit,  whether
natural or man-made.   The difficulty  of  sealing canisters  to the  rocky mine
surfaces could  have allowed  some  infiltration.   In  general,  the emanation rate
from a rock surface would be less  than from soil  because  of  the lower porosity
of rock.  Radon emanation rates from the area east of the pit are comparable to
the  reported  national   average  for  U.S.   soils  of  35   pCi/m^-min   (4).   The
highest radon  emanation rate  was  measured  from a  reportedly  undisturbed soil
area  northwest of  the  mine.   High  radon  emanation rates  in  the area  are
believed to be  due to  a combination of extensive underground mining, cracks in
the earth structure, and the high mineralization of the area.


             TABLE 15.   OPEN PIT COPPER MINE RADON EMANATION RATES

                          Emanation Rates (pCi/m -min)a
Mine Pit (In Order           East of Pit (In Order         NW of  Pit (In  Order
of Increasing  Depth)        of Increasing Distance)       of  Increasing  Distance

      2.3                              15
     14                                25                          100

      4.5                              35                          170
     26                                 1.2                       120
     130                                39                          24
 a)  Picocuries  (10"12  curies)  per square meter per minute.
                                       27

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                                  REFERENCES

1.  National  Council  on   Radiation   Protection  and  Measurements.   Natural
    Background Radiation in the  United States,  NCRP Report No. 45, Washington,
    D.C., 1975.


2.  Code of Federal Regulations, Title 40, Chapter  1, Part 60, Appendix A.


3.  Code of Federal Regulations, Title 40, Chapter  1, Part 50, Appendix B.


4.  Turekian, Karl  K.,  Y.   Noyaki,  and  Larry  K.  Benninger, Geochemistry  of
    Atmospheric  Radon  and  Radon  Products,    Annual   Review  of  Earth  and
    Planetary Sciences, 5:227-255, Palo Alto, California, 1977.


5.  Polanski,  A.   Geochemistry   of   Isotopes,  TT61-31327   (Engl.   Transl.)
    Scientific Publ. Foreign Coop. Center, Warsaw, Poland, 1965.
                                     28

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                                 TECHNICAL REPORT DATA
                          (Please read Instructions on the reverse before completing)
      NO.
   EPA-520/6-82-018
                            2.
       AND SUBTITLE
   Emissions of Naturally  Occurring Radioactivity
   from Aluminum and Copper Industries
                                                          6. PERFORMING ORGANIZATION CODE
                                                          8. PERFORMING ORGANIZATION REPORT NO.
 Vernon E. Andrews
                                                          3. RECIPIENT'S ACCESSION NO.
                                                            REPORT DATE
                                                             Movereber  19S2
PERFORMING ORGANIZATION NAME AND ADDRESS
 U.S. Environmental  Protection Agency
 Office of  Radiation Programs-Las Vegas  Facility
 P.O. Box 18416
 Las Vegas,  Nevada  891H
                                                          1O. PROGRAM ELEMENT NO.
                                                            11. CONTRACT/GRANT NO.
 SPONSORING AGENCY NAME AND ADDRESS
                                                           13. TYPE OF REPORT AND PERIOD COVERED
 Same As Above
                                                           14. SPONSORING AGENCY CODE
-^SUPPLEMENTARY NOTES
1 'This is the sixth
   to the 1 977 Clean
                    in a series  of  reports
                    Air Act Amendments
covering  work  performed in response
^ABSTRACT
     This  report summarizes  five  surveys which were  conducted at a Bauxite mining
 operation,  an Alumina reduction  plant, an Aluminum  reduction plant, an underground
 Copper  mine and mill, and an  open pit Copper mine and  concentrator.  Process
 components  and controlled source releases were sampled for naturally occurring
 radioactivity.  Particular  emphasis was given to Radon-222, Lead-210, and
 Polonium-210 emissions from crushing and drying processes.
                               KEY WORDS AND DOCUMENT ANALYSIS
                 DESCRIPTORS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
 Natural  Radioactivity
 Airborne Wastes
 Exhaust Gases
 Underground Mining
 Beneficiation
 Tailings
 -5lSTHIBUTIONi,IATEMENT

   Release to Public
                                                 Technologically
                                                 Enhanced Radioactivity
                                                19, SECURITY CLASS (ThisReport)
                                                     Unclassified
                                                20. SECURITY CLASS iThis page)
                                                     Unclassified
                                                                             COSATI Field/Group
                                  1808
                                  1302
                                  2102
                                  1308
                              21. NO. OF PAGES

                                        28
                              22. PRICE
              V. 4-77)   PREVIOUS EDITION IS OBSOLETE

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