United States
Environmental Protection
Agency
Radiation
Office of
Radiation Programs
Washington DC 20460
Technical Note
ORP/TAD-79-10
September 1979
Sediment Characteristics
of the 2800 Meter Atlantic
Nuclear Waste Disposal
Site: Radionuclide
Retention Potential
Biogenous Materials
v v v Y
Terrigenous
Materials
Clay
Minerals
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TECHNICAL NOTE
ORP/TAD-79-10
SEDIMENT CHARACTERISTICS
OF THE ,
2800 METER ATLANTIC NUCLEAR WASTE DISPOSAL SITE:
RADIONUCLIDE RETENTION POTENTIAL
by
James Neiheisel
Technology Assessment Division
Office of Radiation Programs
U.S. Environmental Protection Agency
Washington, D.C. 20460
September 1979
This report was prepared with the technical support of
the United States Army, Corps of Engineers under Inter-
agency Agreement EPA-78-H0152
Project Officer
Robert S. Dyer
Radiation Source Analysis Branch
Technology Assessment Division
Office of Radiation Programs
U.S. Environmental Protection Agency
Washington, D.C. 20460
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EPA REVIEW NOTICE
This report has been reviewed by the Office of Radiation Programs, U.S.
Environmental Protection Agency (EPA) and approved for publication. Approval
does not signify that the contents necessarily reflect 'che views and policies
of the EPA. Neither the United States nor the EPA makes any warranty,
expressed or implied, or assumes any legal liability or responsibility of any
information, apparatus, product or process disclosed, or represents that its
use would not infringe privately owned rights.
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EPA TECHNICAL PUBLICATIONS
Publications of the Environmental Protection Agency's (EPA) Office of
Radiation Programs (ORP) are available in paper copy, as long as the EPA/ORP
supply is available, or from the National Technical Information Service
(NTIS), Springfield, VA 22161.
The following reports are part of the EPA/ORP 1976 Ocean Disposal Report
Series:
ORP/TAD-79-1 Materials for Containment of Low-Level Nuclear Waste in the Deep
Ocean
ORP/TAD-79-2 On Board Corrosion Analysis of a Recovered;Drum from the
Atlantic 2800 Meter Radioactive Waste Disposal Site
ORP/TAD-79-3 Analysis and Evaluation of a Radioactive Waste Package Retrieved
from the Atlantic 2800 Meter Disposal Site
I
ORP/TAD-79-'4 Reports of Infaunal Analyses Conducted on Biota Collected at the
Atlantic 2800 Meter Radioactive Waste Disposal Site
ORP/TAD-79-5 Geologic Observations of the Atlantic 2800iMeter Radioactive
Waste Dumpsite
ORP/TAD-79-6 Sediment Geochemistry of the 280.0 Meter Atlantic Radioactive
Waste Disposal Site
ORP/TAD-79-7 Ocean Current Measurements at the Atlantic 2800 Meter
Radioactive Waste Disposal Site
ORP/TAD-79-8 Survey Coordination and Operations Reoort -i EPA Atlantic 2800
Meter Radioactive Waste Disposal Site Survey
ORP/TAD-79-9 1976 Site Specific Survey of the Atlantic 2800 Meter Deepwater
Radioactive Waste Dumpsite: Radiochemistry
ORP/TAD-79-10 Sediment Characteristics of the 2800 Meter Atlantic Nuclear
Waste Disposal Site
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TABLE OF CONTENTS
Page
List of Tables and Figures .. 1v
Abstract ,!.......................,:. ,\\\\'
Introduction. ......................*.*.**.*.*.*.'**.'.*.'**.""** *" * " "T
Geological Setting. ....,...........'.".'.'.'.".*'.'.] **.["" * * <,
Sample Locations..'...,.,.-.... i ....".*.'.*.".*."'."***.* 1
Analytical Methods. '.'' *..' */. I'.'.'.*.''.*'. '''%
Sediment Texture ....*.*.*.*.*.*.".*.".*.".*.".*.*."* o
Sedimentary Parameters.....; *.....!!!! ' ''' *r * t
Physical Properties. ....'.":....'.'...*.".".".*.' *."." * * * ..'."*.','**"'""
Sediment Composition. ............*..*.'.*.*'.*.'.*.*.'."*"' * * *
Biogenous Materials....., '*!.*.*.* I.' .*.' J.".' J,? '.I'.'.'. .*','"' ' in
Terrigenous Materials. *.*.".!*.*.*.".*.*.*.'.".'.". 1 *" ' * " 16
Clay Minerals. ......... t ...*.".'..'.".*.*.'.... ''< ' ''''16
Characteristics of Clay Minerals..'.".". *. *.'.'.".".'.'.'.'. *.'.". *} * * -*'*' ^
Cation Exchange Capacity ..*.'.'.'.*" " *21
Distribution Coefficient, (Kd), Considerations'.'.'.'.'."" 21
Sediment Source Considerations............. . ..,',*.' .*.'.'.'"' "23
Sedimentation Processes Affecting Radipnuclide " " '";".
Distribution in Sediment..'..'............;...... 25
Summary and Conclusions..........,.,.........'.'..'..'..''.."'"'" 26
Acknowledgements..........\ ....... ^ *';'* *" * "27
Reference Cited ;'.. *".'.".I!!".'.11*.*.".!*.' 21
.8
10
iii
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LIST OF TABLES AND FIGURES
Page
TABLES
1. Texture Physical Properties and Sedimentary
Parameters of Sediment from the 2800 Meter
Atlantic Nuclear Waste Disposal Site and Vicinity 6
2. Mineral Suite of Sand-Silt-Clay Size Fractions and Average
Sediment Composition from the 2800 Meter Atlantic Nuclear
Waste Disposal Site and Vicinity 9
3. Heavy Mineral Analysis of Sand-Size Sediment from the
2800 Meter Atlantic Nuclear Waste Disposal Site and Vicinity...17
4. Clay Minerals of Clay-Size Fraction of Sediments from the
2800 Meter Atlantic Nuclear Waste Disposal Site and Vicinity...18
5. Cation Exchange Capacity of Sediment from 2800 Meter
Atlantic Nuclear Waste Disposal Site 20
FIGURES
1. Sediment Sample Locations of 2800 Meter Atlantic Nuclear
Waste Site and Vicinity taken in 1975 and 1976 2
2. Triangular Textural Diagram of Sediment from the 2800 Meter
Atlantic Nuclear Waste Disposal Site 7
3. Photomicrograph of Sand-Size Fraction of Sediment from 2800
Meter Atlantic Nuclear Waste Disposal Site ............... > ..... 11
4. Scanning Electron Micrograph of Silt-Size Material from 2800
Meter Atlantic Nuclear Waste Disposal Site ............... . ..... 12
5. Scanning Electron Micrograph of Silt-Size Material from 2800
Meter Atlantic Nuclear Waste Disposal Site ............... < ..... 13
6. Scanning Electron Micrograph of Clay-Size Material from 2800
Meter Atlantic Nuclear Waste Disposal Site ..................... 1^
7. Scanning Electron Micrograph of Clay-Size Material from 2800
Meter Atlantic Nuclear Waste Disposal Site ..................... 15
8. Direction of Longshore Currents Near Shore, Turbidity Flow
Down the Submarine Canyons, and Predominant Bottom Flow in
Vicinity of 2800 Meter Atlantic Waste Site ..................... 24
iv
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ABSTRACT
Sediment Characteristics of the 2800 Meter
_ Atlantic Nuclear Waste Disposal Site:
Radionuclide Retention Potential
by
James Neiheisel ^
The sediments of the abandoned 2800 meter Atlantic nuclear waste dumpsite
have been analyzed for texture, mineral composition, physical properties,
cation exchange capacity and factors effecting sediment deposition,- as part of
an extensive program by the Environmental Protection Agency to evaluate ocean
Si!?" i aSHSr\, aljer?ative nuclear> waste disposal method. The sediments
physical and chemical properties are evaluated in the light of the geologic
The sediments are relatively uniform silty clays and clayey silts
comprised of approximately one-third biogenous carbonate materials, one-third
terrigenous materials and one-third clay minerals. The biogenious materials in
the sand and upper silt-size fraction are predominantly foraminifera with
minor amounts of diatoms while coccoliths dominate the finer silt and clay
size fractions. The terrigenous materials in the course sediment fractions
are predominantly quartz and feldspar with minor amounts of mica, glauconite,
and heavy minerals. Clay minerals, of the clay-size fraction, in order of
abundance, include illite, kaolinite, chlorite and montmorillonite.
Relatively high cation exchange capacity in the sediment (15.2-25 l»
meq/lOOg) is attributed to the clay minerals comprising approximately
one-third of the sediment. Correspondingly high Kd values might also be
expected as a result of sorption of radionuclides onto clay minerals with most
favorable conditions related to PH, Eh, and other environmental factors. The
biogenous fraction might also be expected to retain some strontium-90 by
isomorphous substitution of this radionuclide for calcium.
Diagnostic heavy minerals in the sand-size fraction reflect the source
areas as predominantly the adjacent continental shelf, and provide important
clues concerning the mechanisms effecting transport and deposition of the
sediment. Longshore currents along the coast funnel sediment into the Hudson
Canyon and turbidity currents transport sediment down the submarine canyon;
some of this sediment is advected in a southwesterly direction from the
submarine canyon by contour currents for deposition along the continental
rise. The net deposition at the waste site thus consists of the "rain" of
biogenous microorganisms, the transport of sediment from the coastal and
continental shelf area by turbidity currents via submarine canyons, and
transport of sediment along the continental rise by prevailing contour
currents.
The effectiveness of the sediment barrier relates to timely burial of the
waste drum prior to leachate release from ruptured or corroded drums as well
as freedom from "short circuiting" effects such as bioturbation or other
mechanisms capable of providing migration pathways for the radionuclides.
v
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Introduction
The Ocean Disposal Program of the Environmental Protection Agency is
currently involved in investigating abandoned nuclear waste disposal sites in
the Pacific and Atlantic Oceans. The condition of the 55 gallon steel waste
drums deposited at these sites between 1950 and 1962 and their impact on the
ocean environment is under extensive investigation. Information gained by
field and laboratory investigations of the factors effecting the stability of
the waste site will enable evaluation of ocean disposal as a potential
alternative method to present land burial disposal methods. An evaluation of
the ability of the sediment to act as a barrier to the migration of
radionuclides leached from the waste form and the geological stability of the
site will provide important data for considerations governing; future ocean
disposal.
At present, little is known about deep ocean sediment as regards its
physical properties, mineral composition, or ability to effect sorption and
retention of radionuclides. This laboratory investigation of sediment samples
from the 2800 meter site reports on the geologic setting, sediment texture,
physical properties, mineral composition, and chemical parameters of one of
the major abandoned waste sites. Consideration is given to the potential
ability of this sediment to act as a geochemical barrier in the sorption of
radionuclides and preventing their migration from the disposal site. Site
stability is evaluated in light of the sedimentological findings, including
use of diagnostic heavy minerals to delineate source areas, as well as field
observations of the hydrodynamic factors.
Geologic Setting
The 2800 meter Atlantic site, situated approximately 190 kilometers off
the New Jersey coast, comprises an area of 256 km2 centered at 38° 39«N
and 720 00' w> The bottom topography at this site is a smooth, gently
sloping surface typical of the upper continental rise (Figure 1).
The Hudson Canyon, approximately 70 km northeast of the 2800 meter site,
is the largest submarine canyon of the Atlantic continental shelf. Submarine
canyons are believed to act as sediment traps that funnel terrigenous
sediments down the slope as turbidity currents. Deltas on the abyssal plain
at the foot of the Hudson Canyon have been described by Pratt (1) and other
investigators as material transported via the thalweg of the canyon to this
deposition site. Some of the sediment undoubtedly overflows the canyon or is
resuspended from the submarine canyons by hydrodynamic agents and other
mechanisms including biological activity. This sediment source as well as
sediment transported by bottom contour currents and the biogenous materials of
the marine environment constitute the materials available for deposition at
the waste site.
Observations of the 2800 meter nuclear waste by the SRV Alvin during 1975
and 1976 by Rawson and Ryan (2) reveal that the site is carpeted by fine
grained muds. Photographs of the steel drums reveal sediment plumes extending
in a southwesterly direction; this reflects prevailing or strongest current
flow from the northeast predominantly parallel to bottom topography. Current
measurements from meters deployed during field operations in August and
November 1976 indicate diurnally varying oscillatory currents up to 0.5 knots
with strongest velocity flow in a southwesterly direction.
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Sample Locations
The sample locations and type recovery of the sediment samples are
depicted in Figure 1. In addition to the core samples (to 40 cm depth) in the
2800 meter site area, several Smith-Mclntire grab samples were obtained at the
waste site, and other locations in the adjacent shelf edge, slope, and
submarine canyons, for contrast analyses. A Smith-Mclntire grab sample (SH2)
.was collected from 100 meter depth in the ancestoral Hudson River Valley which
existed in this location during the Pleistocene Epoch. Another sample,
(SH16), was obtained in the Hudson Canyon at the 2000 meter depth at the foot
of the continental slope (Figure 1). Other grab samples were obtained at the
2000 meter contour, approximately 110 kilometers northwest of the Hudson
Canyon between Block Canyon and Atlantis Canyon (SH15), and another sample
approximately 40 kilometers upslope from the nuclear waste disposal site
(SH4A). The comparison of the texture and mineral compositon of these samples
with those from the waste dumpsite provide important clues regarding the
possible source area and transport pathways of the sediment to the deposition
site in the study area.
Analytical Methods
^~~~~ -^^^^« |
The texture of the sediment was determined by standard sieving and
hydrometer techniques and a grain size distribution curve constructed from
this data. The sand, silt, and clay size fractions were retained for mineral
identification of each size fraction. The mineral identification of the
sand-size fraction was determined by standard petrographic techniques while
x-ray diffraction, scanning electron microscopy, and chemical techniques were
used in the identification of the finer silt and clay-size fractions. X-ray
diffraction analysis of the clay minerals in the clay-size fraction was in
accordance with Biscaye, 1965 (3). The special techniques necessary to
distinguish kaolinite from chlorite, utilized the slow scan techniques
proposed by Bicaye, 1964 (4); the areas of the 3.54 A peak were measured for
chlorite and the areas of the 3.58 A peak for kaolinite. Carbonate
evaluations were made on each of the size fractions by acid leach techniques
using 1:4HC1. The fractional components determined on each size fraction was
weighted by the grain size distribution curve and the sum recorded as the
average for the sample.
The cation exchange capacity determinations were made using a method
similar to that of Zaytseva, as briefly described by Sayles and Mangelsdorf
(5). The samples were squeezed into a stainless steel device and the pore
water collected and analyzed for Na+, K+, Mg++, and Ca++; the remaining
squeeze cake was split into two parts. One part was used for determination of
the residual water content (110oc drying) and the other was leached of
residual sea water and exchange cations, using a succession of washes (80%
methanol, IN NH4C1 adjusted to pH 8 with NH4 OH). The exchange cations were
calculated by subtracting the seawater contribution from the total leach
solution. The purpose of this_ involved procedure was to circumvent the
exchange cation-seawater reequiTibrium (Donnan effect) that occurs during the
washing 'step which' proceeds the .exchange dn the, more ..traditional .approach.
The pH adjustment and the use:;of methanol [were used to:minimize ;solutiqnpfjl
during leaching.
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Sedimentary parameters were computed from the grain size curve by
standard procedures. Physical parameters, including bulk specific gravity,
moisture, porosity, and Atterberg limits were performed in accordance with
U S Army Corps of Engineers standard soil testing procedures (b). ihese
parameters are used in correlating uniformity of conditions within the
sediment and in computations for radionuclide retention.
Any water loss as a result of storing samples for three years before
analysis is considered to be inconsequential for most of the parameters
tested. The physical parameters and cation exchange capacity, most
susceptible to water loss, were performed on samples well contained and
observed to be in a highly plastic state so as not to detract from the
significant information presented.
Sediment Texture
The sediment texture of the upper continental rise has been described on
a regional basis by several investigators using various classifications.
Emery (7) and others, stressing grain size, depict the general region as
comprised of silt and clay; others stressing the relatively high biogenous
content, have described the sediment as globigerina ooze. The texture
classification used in this report is in accordance with Shepards (8)
classification and particle sizes comply with EM1110-2-1906, (6); sand-size
consists of particles between 5.00 and 0.074mm size, silt-size consists of
particles between 0.074 and 0.002mm size, and clay-size material consists of
particles less than 0.002mm size. A ternary plot of the sand-silt-clay values
and sediment description is depicted in Figure 2 and listed in Table 1.
The predominant sediment type at the 2800 meter site is clayey silt with
subordinate amounts of silty-clay and silt (Figure 2). Sand is abundant only
in- the Pleistocene Hudson River sample (SH2) taken at the edge of the
continental shelf and the sample from 2000 meter depth between Block and
Atlantis Canyons (SH15). Within the 2800 meter study area, the sand content
averages 6.3 percent and ranges between 2 and 14 percent; the silt content
averages 55.0 percent, ranging between 42 and 76 percent; the clay content
averages 38.7 percent ranging between 20 and 50 percent (Table 1). The
sediment samples within the 2800 meter nuclear waste disposal site are
generally uniform in texture from the surface to 40 cm depth and throughout
the area; samples outside the area are less uniform.
Stanley and Wear (9) in a survey of surface sediments on the outer shelf,
shelf break, and upper slope between Norfolk and Wilmington canyons have
disclosed a transition textural facies which generally parallels the upper
continental slope between 250 and 300 meter depth, except at canyon heads.
This "mud-line" (> 0.062mm size) , identifies the long-term separation of
erosional versus depositional regimes and thus serves as a major energy-level
boundary on the upper continental slope. In this investigation, all the
sample locations except SH15 have a texture in general compliance with the
"mud-line" concept. Sample location SH15 at 2000 meter depth contains sand,
silt, and clay in generally similar amounts and this coarser texture may be
related to slumping or canyon controlled sedimentation.
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Sedimentary Parameters
!
The sedimentary parameters are statistical measurements derived from the
textural grain-size distribution curve and are commonly used in most
sedimentological investigations. These parameters have most application in
the higher energy zone at shallower depths (10) but are included in this
investigation to reflect on the deposit ional environment, provenance, and for
correlation purposes. The sedimentary parameters considered are in accordance
with standard procedures and include the median diameter, standard deviation,
skewness, and kurtosis. The values for the various station locations are
listed in Table 1.
The median diameter is the 50 percentile of the grain size distribution
curve. The median diameter for the samples from the 2800 meter site is
The standard deviation is a statistical measurement of the amount of
sorting and is one of the more useful parameters for correlation purposes.
The standard deviation of samples outside the waste site ranges from 0.48, for
the sandy Pleistocene river sample on the shelf, to 1.39 for the sample at the
foot of the continental slope at 2000 meter depth at location SH 15 (Figure
1). More uniform conditions prevail at the waste site. The standard
deviation for dive 538 samples at 4 cm intervals from surface to 20 cm depth
are respectively: 3.78, 3.20, 4.57, 3.60, and 3.47. Standard deviation for
two samples from dive 584 are 2.8l and 3.13 while for dive 58'j values are
3.10, 2.96, 2.87, and 2.39 (Table 1). Thus, it is apparent that generally
uniform conditions prevail with no apparent trend with depth at the waste site.
In accordance with Friedman's classification (11) for sorting, the
samples range from well sorted (Class 1) to extremely poorly sorted (Class 6)
with progressively poorer sorting in the seaward direction. The Pleistocene
River sample, (SH2), is well sorted (Class 1), while samples SH15 and SH16, at
the base of the continental shelf, are moderately well sorted (Class 3) All
samples from the 2800 meter waste site and sample SH14 (immediately upslope of
the waste site) are extremely poorly sorted (Class 6). The sorting in general
becomes poorer as the clay content increases and this parameter correlates
well with the "mud-line" concept cited previously. ;
The skewness is a measure of the direction and degree of overall
deviation from symmetry. It is a dimensionless number which expresses tht
predominance of coarse or fine admixtures and may be positive or negative.
Positive values demonstrate that the curve is skewed toward the finer grain
sizes and may indicate a stronger depositional environment. Negative values,
in turn, show a tail toward the coarser grain sizes and may, therefore,
reflect some removal of fines. The skewness values at the waste site range
from -1.35 to +2.80 with the highest value at greatest depth from core samples
of Dive 585. Near surface samples to 7cm depth at all locations have negative
values which indicates a different sedimentation rate than the intermediate
depth positive values (Table 1). No trend is apparent from the middle to the
bottom of core depth (Table 1). i
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SILT
Figure 2. Triangular diagram depicting sediment samples from North Atlantic
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oneparcf (1954) °
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8
The kurtosis is a measure of the peakedness of the curve. It shows the
relationship of the sorting within the main body of the curve to that of the
tails. A kurtosis of 1 is normal whereas a kurtosis of 2 is leptokurtic,
meaning that it is excessively peaked by a factor of 2; a leptokurtic sample
is better sorted in the main body than in the tails. All the samples at the
waste site are leptokurtic with values ranging between 2.48 and 4.20 (Table
1). No trend is apparent over the area of the waste site or with depth, but,
it is significant that all samples are better sorted in the main body than in
the tails. <
While sedimentary parameters tell little of the adjustment of the
sediments td their present environment or of provenance, these parameters can
reflect homogeneous conditions within an area. These parameters enable a
relatively inexpensive means of establishing if uniformity of physical
conditions prevails within the area investigated.
Physical Properties
Physical properties bf the sediments provide basic data necessary for
prediction of radionuclide migration in sediment. Some of these physical
parameters are listed in Table 1.
The water content (percent dry weight) varies from 209 percent to 62
percent in the 2800 meters, study site. Within the 2800 meter site the lowest
water content is associated with samples containing the higher sand content.
The lowest water content occurs in the sandy samples (SH 2 and SH 15) outside
the study area.
The.bulk density values of the samples from the 2800 meter site varies
between 0.49 gcm-3 and 1.11| gcm"3 with;values depending on the amount of
interstitial water. Sample number 22 from dive 585 is a surface sample and
has the lowest measured bulk density of 0.36 gcm-3 and. the highest water
content of 240 percent (dry weight) while sample number 2, (5 to 12.5 cm
depth) from dive 585 has the highest measured bulk density value of 1.14
gcm-3 and a correspondingly low water content of 46 percent (Table 1).
The porosity of the sediment within the nuclear waste dump site ranges
between 0.75 and 0.86 with higher values generally correlating with higher
water content (Table 1). Both the bulk specific gravity
and porosity values are used in computing the radionuclide retention
capability of the sediment.
.Atterberg Limits are useful in describing quantitatively the effect of
varying water content on the consistency of fine grained sediments. The
boundaries are defined by trie water content which produces a specified
consistency. The liquid limit (LL) defines the water content at which the
sediment closes with standard mechanical manupliation, while the plastic limit
(PL) is the water content at which the sediment begins to crumble or break
apart. The shrinkage limit (SL) is the water content at which the soil
reaches its theoretical minimum volume after drying from a saturated
condition. Atterberg Limits for 6 samples within the 2800 meter waste site,
and one sample (SH15) outside the area, are listed in Table 1. All the
samples at the nuclear waste site display marked similarity and uniformity
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10
with depth, whereas the sample outside the area has markedly different
values. In themselves, the Atterberg Limits mean little, but they are very
useful as indices to significant properties of sediments. For example, the
difference between the plastic and liquid limits, termed the plasticity index
(PI), represents the range in water contents through which the sediment is in
a plastic state and is inversely proportional to the ease with which water
passes through the sediment. Thus, the low PI value of 18 for the sample
outside the study site (SH15) reflects a more permeable sediment as compared
to the range of PI values of 59 to 76 for the less permeable samples within
the 2800 meter nuclear waste site. The Atterberg limits are also useful in
identifying and classifying sediments and for correlation purposes.
Sediment Composition
The mineral composition of the sediment varies considerably within the
sand, silt, and clay fractions. Since both mineral composition and grain size
are important factors in assessing the radionuclide retention capability, the
sediment in this investigation is treated in as quantitative manner as
possible in order to obtain realistic values. The fractional components are
reported for each size fraction and the average composition of"the sediment is
the sum of these fractional components reduced to their representation in the
total sample as shown on the grain size distribution curve.
The average mineral composition for 60 samples from the Atlantic upper
continenatal rise of the mid-Atlantic States by Hathaway (12) is as follows:
quartz, 17 percent; feldspar, 12 percent, carbonate, 18 percent; clay
minerals, 53 percent, hornblende, trace. As compared with the 2800 meter site
the carbonate content is greater (37 percent) and the clay content less (30
percent).
The carbonate is probably greater at the 2800 meter site because of its
location farther seaward on the upper continental slope. This increase of
carbonate in a seaward direction off the North Atlantic continental shelf has
also been demonstrated by Turekian (13).
The sediment composition is important in any assessment of the
radionuclide retention capabilities of the sediment. In order to group
materials of similar chemical behavior as regards their barrier potential to
migration of radionuclides from nuclear waste leachate, the sediment is
classified into a biogenous group, terrigenous sand and silt group, and'a clay
mineral group.
Biogenous Materials
Biogenous materials, originating from the ocean environment, comprise
more than a third of the sediment. Reported as carbonate and miscellaneous
diatoms in Table 2, these materials are shown to be most abundant in the sand
fraction but they are also abundant in all sieve sizes (Table 2). The
calcareous foraminifera comprise the bulk of the sand (Figure 3) and are
predominantly the planktonic genus Globigerina.
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11
Figure 3. Photomicrograph (26X) of sand-size fraction of sediment core 7
5-12 cm depth, from Dive 585 in the 2800 meter Atlantic nuclear waste disposal
site. Foraminifera comprises the predominant portion of the sand.
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12
Figure 4. Scanning Electron Microgram (4800X) of rill:fract.
from 2800 meter depth at. dive location 584 (0 -5 cm depth)
in Atlantic Nuclear Waste Dumpsite. The diatom and t
fragment (upper right) constitute the larger biogenous
while Coccoliths (lower right) constitute the smaller
i>io(jf:ngus materials.
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13
Figure 5. Scanning Electron Micrgraph (2900X) of Silt Fraction
from dive 585 (0-5 cm depth) in 2800 meter Atlantic Nuclear
Waste Dumpsite. Broken, spherical, calarcous, Globeirigerina
horamimfera (upper right) and Coccoliths comprise the
predominate biogenous silt fraction.
-------
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i&frc;- % /** r
1 «» * _ v^ *t 4,1 ««.,
Figure 7. Scanning Electron Micrograph (14,000X1. of calareous
Coccolith tests from dive'585 location (15 cm depth) in
2800 Meter Atlantic Nuclear Waste Dumpsite.
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16
Calcareous planktonic coccolith tests (less than 30 microns in diameter)
constitutes the biogenous material of the lower silt and cla-y-size fraction
(Figures U, 5, 6, and 7). Minor calcareous corallttes and siliceous diatoms
also occur in the upper silt-size fractions but these microorganisms seldom
comprise more than a few percent of the biogenous fraction.
Certain radionuclides, such as strontium-90 could possibly exchange for
some of the calcium cation of the carbonate fraction and thus the biogenous
material has some potential for radionuclide retention by the sediment.
Terrigenous Materials
Terrigenous materials include all the non-biogenous materials except the
clay minerals and the predominant amount occurs in the silt-size fraction.
The terrigenous materials are predominantly quartz and feldspar but also
includes minor amounts of mica (biotite, muscovite, and chlorite) and very
minor amounts of detrital heavy minerals and glauconite (Table 2). The
glauconite generally comprises less than one percent of the sediment and while
marine in origin this material is largely derived as detrital material from
erosion of Cretaceous formations of the adjacent continent.
Special detail to the varieties of feldspar and detrital heavy minerals
lend support to the source of the sediment but most of these materials do not
contribute significantly to radionuclide retention. Heavy minerals from the
2800 meter site comprise less than one percent of the terrigenous material;
fraction representation is listed in Table 3. The ratio of heavy mineral
species reflect sources from, the mineral provinces delineated on the adjacent
continental shelf and boundries between these provinces are essentially
perpendicular to the shelf break. The ratios of these minerals will be used
in a later section to reflect on the source area and the hydrodynamic agencies
involved in effecting sediment deposition at the 2800 meter site.
Pebble size chert and quartzite rock particles are unique to the
Pleistocene Hudson River sample (SH2) while diagnostic gabbro rock particles
of upper sand size (JJ-Smm) occur in sample SH15 from the bottom of the
continental slope between Atlantis and Block Canyons. The presence of these
rock particles in either pebble or upper sand size is of correlative value to
distinguish the New England coast sediments from those originating in the
region of the New York Bight.
Clay Minerals
The clay minerals comprise approximately a third of the sediment at the
2800 meter site and constitute the bulk of the clay-size fraction. Their
unique dimensions (less than 2 microns diameter), large surface area, high
cation exchange capacity, and high sorption potential for radionuclides makes
the clay minerals the most significant as regards the potential of the
sediment to act as a barrier to the migration of radioactive waste.
Illite is the principal mineral of the clay-mineral suite with a range
between 50 and 60 percent. Kaolinite and chlorite occur in generally similar
proportions in the clay-mineral suite with ranges between 12 and 30 percent
(Table U). Because of the difficulty in obtaining a clear resolution of
-------
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18
Table 4. Clay Minerals of Clay-Size Fraction of Sediments from
the 2800 meter Atlantic Nucelar Waste Disposal Site and Vicinity
%_ Clay Mineral Suite
Location Lab No.
SH4A (2000m)
SH15 (2000m)
SH16 (2000m)
SH20 (2800m)
SH25B (2800m)
SH26B (2800m)
DIVE 583
BOX 2,- 0-5 cm
DIVE 583
BOX 2, 5-8cm
DIVE 583
BOX 2, 8-12cm
DIVE 583
BOX 2, 12-l4cm
DIVE 583
BOX 2, l4-l8cm
DIVE 583
TUBE 1, 22.5-30
DIVE 584
TUBE 2, 0-1 Ocm
DIVE 584
BOX 1, 0-5cm
DIVE 585
TUBE 4, 0-7 cm
DIVE 595
TUBE 7, 0-7 cm
DIVE 585
TUBE 7, 7-1 2cm
DIVE 585
TUBE 7, 12-1 7cm
DIVE 585
TUBE 7, 17-22cm
DIVE 585
TUBE 3, 0-5 cm
DIVE 589
TUBE 2, 0-10cm
DIVE 589
TUBE 2, 10-15cm
9
10
11
14
12
13
16
17
18
19
20
21
15
6
22
1
2
3
4
5
23
7
Illite. Kaolinite
47
60
60
52
51
52
54 ,
56
58 .
58
54
55
50
58
58
52
54
52
54
55
57
50
30
19
.20
20
20
20
21
18
,,16
,
18
18
23
21
17
17
18
23
20
19
18
20
30
Chlorite Montmorillonite
16
18
15
18
18
20
15
18
16
16
18
12
21
17
17
18
15
20
19
17
17
12
7
5
5
10
9
8
10
8
10
8
10
10
8
8
8
12
8
8
8
10
6
8
Note: 1. Chlorite fraction includes trace amounts of vermiculite.
2. Montmorillonite includes mixed-layer clay (chlorite-
montmorillonite)
3. Carbonate comprises between 15 and 39 percent of the clay
fraction.
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19 :
chlorite and kaolinite on x-ray diffractograms both the slow scan speed and
the regular scan x-ray diffraction techniques were employed for more positive
identification of these two minerals. The values of the clay minerals at the
nuclear waste site are in general agreement with the values obtained by
Hathaway for the upper continental rise sediments in this region (12) Dayal
et al. (14), found chlorite to be slightly in excess of kaolinite at the
nuclear waste disposal site, however, the sum of both kaolinite and chlorite
are in general agreement in all the' investigations cited. Montmorillonite and
mixed-layer montmorillionite clay occur in subordinate amounts at all site
locations with values generally less than 10 percent of the clay-mineral
suite. The clay mineralogy is fairly consistent throughout the 2800 meter
Atlantic nuclear waste disposal site.
Characteristics of Clay Minerals
In order to make use of clay minerals in investigations concerning
nuclear waste disposal, it is necessary to have a general concept of the
chemical and structural make up of the common clay minerals. The following
treatment is presented for those readers having little familiarity with the
common clay minerals at the Atlantic sites.
The common clay minerals are hydrated silicates comprised of thin sheets
held together by predominantly ionic bond; each sheet consists of planes of
cations (silica, aluminum, magnesium, or iron) in which the individual cation
is surrounded by either four (top sheet) or six (lower sheet) oxygen and
hydroxyl ions. The main subdivisions of the clays are based on how these
sheets are stacked as follows:
a. Kaolinite of 1:1 clays contain one silicia sheet (silicon-oxygen
tetrahedron) and one sheet of either aluminum, magnesium, or iron
(aluminum-oxygen-hydroxol octahedron).
I
b. Illites and montmorillonites of 2:1 clays contain two silica sheets
which are on either side of an aluminum, magnesium, or iron sheet.
In addition, the montmorillonites contain one or two water sheets.
c. Chlorite of 2:2 clays contain two silica sheets which alternate with
two magnesium or iron sheets; the latter have bonds of unequal
strength.
I
Typical clay structures have a thickness of 7 Angstroms as in the case of
kaolinite, 10 Angstroms for illite, 14 Angstroms for chlorite and 12 to 14
Angstroms for montmorillonite. Water between montmorillonite tetrahedral
layers increases the thickness 2.5 to 4 Angstroms depending on presence of one
of two water layers fixed respectively by Ca++ and Mg++ or Na+. The
K+ fixed to illite, does not add much thickness to the clay structure
because it fits into the hexagonal hole in the silica tetrahedrom sheets.
Chlorite contains no interlayer water but is similar to montmorillonite in
size due to a brucite layer. Isomorphous substitution may take place in the
clay mineral structure with the amount depending on charge, ionic radius,
coordination number or solubility of the participating ions. Common
substitution in clay minerals might involve an Fe+++ and A1+++ substitute
for Si++++ in the tetrahedral layer while Mg++ and Fe++ substitute for
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20
Table 5. Cation Exchange Capacity of Sediment from 2800
Meter Atlantic Nuclear Waste Disposal Site.
Exchangeable Cations (meq/lOOg)
Field No.
SH26
SH20
Dive 584
Dive 583
Dive 585
Dive 589
Lab No.
13
14
15
16
21
23
Na+
7.0
8.0
11.3
9.4
6.9
7.3
K+
0.8
1.6
2.6
2.1
1.4
1.7
Mg++ Ca"1"1" Stations
4.1
4.3
6.3
5.3
3.4
4.2
3.3
3.5
5.2
4.0
3.3
3.6
15.2
17.4
25.4
20.8
15.0
16.8
Notes: 1. Method in accordance with Zaytseva non-rinse technique. Tested by
K. Beck.
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21
A1+++ in the octahedral layer. The result of a lesser valence cation
substitution for a higher valence cation is a negative (-) charge. Most of
the charge on kaolinite is usually along the edge but for raontmorillonite is
along the surface. Cations, such as Ca++, Na+, H+, Mg++, and K+,
are adsorbed on these positions to neutralize the charge when the clay
particle encounters a cation-rich environment or receives radionuclides from
waste drums. Radioactive waste contains considerable strointium and cesium
which could substitute for calcium or sodium under proper environmental
conditions.
Cation Exchange Capacity
The measurement of cation exchange capacity is correlative with the
ability of a sediment to adsorb radionuclides from a radioactive waste
source. This measurement is expressed in terms of milliequivalents per 100
grams and varies for the different clay minerals. The general range in cation
exchange capacity of the common clay minerals, in milliequivalents, is 3-50
for kaolinite, 10-40 for chlorite, 10-40 for illite, and 80-150 for
montmorillonite. Thus, sediment rich in montmorillonite would have a higher
cation exchange capacity than a kaolinite-rich sediment.
The cation exchange capacity ranges between 15.0 and 25.4 meq/lOOg at the
2800 meter site (Table 5). Dayal, et al., (14), reporting on the cation
exchange capacity with depth for cores taken by the SRV Alvin, found a range
between 35 to 55 meq/lOOg. No significant trend in the total cation exchange
capacity with depth of burial was observed and it was concluded that fixation
of exchangeable cations does not occur during early diagenesis.
The presence of organic matter in the sediment could also influence the
cation exchange capacity of a sediment. Experiments in recent soils reveal
cation exchange capacity values of 150-500 meq/lOOg for organic matter. The
organic matter at the waste site, however, is probably negligible since values
of total organic carbon reported for this section of the 'ocean floor are on
the order of 0.05 percent of the sediment (Emery and Uchupi (10).
Distribution Coefficient (Kd) Considerations
The complex physicochemical reactions that occurs between radionuclides
in solution and the ocean sediment is termed sorption. Sorption includes such
phenomena as adsorption, ion exchange, colloid filtration, reversible
precipitation, and irreversible mineralization. Sorption is expressed in
terms of the distribution coefficient (Kd) which is the ratio of the sorbed
and dissolved fraction of the radiosotope in the sediment. Knowledge of the
Kd of a given radionuclide in sediment, together with information concerning
the bulk density and porosity of the in situ state, may be used to estimate
the retardation factor, Rd, for groundwater transport of that radionuclide
using the equation Rd = 1 + KdP/E, where p is the bulk density of the medium
and E is the porosity. The bulk density used in the equation must be reported
in units of g/cm3 to obtain a dimensionless Rd.
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22
The bulk density of the samples from the 2800 meter nuclear waste
disposal site range between 0.49 to 1.14 g/cm3 with a general average of
0.68 g/cm3. The porosity has a relatively narrow range between 0.75 and
0.81.
Considerable Kd values for continental geologic formations or soils have
been reported in the literature, however, such data is not directly applicable
to the ocean sediment environment. Also much of this data is subject to
inadequate characterization of the solid medium or to inappropriate
experimental design of the testing method. Some laboratory Kd values for
strontium-90 and cesium-137 using clay minerals have been reported by Ames and
Rai (15). Such data may possible compare to those expected in ocean sediment;
this data is listed below for clay minerals.
Clay Minerals
Kds
Sr-90
Cs-137
Montmorillite
Kaolinite
Illite
104
15
100
45
400
Heath(l6), reporting on preliminary results of distribution coefficient
experiments on montmorillonite-rich Pacific Ocean deep sea sediment indicated
Kd values for cesium 137 varies from 3000 to 20,000 and for strontium 90
values range from 100 to 6000. As contrasted to continental deposits, the
marine clays appear to be superior in retaining radionuclides. Much needs to
be done, however, to get reliable data on the interactions between dissolved
waste components and deep-sea sediments. Kd measurements in the laboratory
have been conducted in an oxidizing environment, whereas in reality, ocean
sediment is largely a reducing environment. Bondietti and Francis (17) have
demonstrated the role of the oxidation state in controlling the solubility of
technetium and neptunium from a nuclear waste source; in a reducing
environment both radionuclides have high Kd values yet in oxidizing conditions
both elements are highly mobile and not readily retained by the geologic
media. The pH and Eh are also important factors governing solubility. Both
pH and Eh (oxidation-reduction) measurements should be made as soon as the
sediment sample is received on board the vessel. Measurements for Kd's in the
laboratory should match these measured field parameters.
In addition to the need for laboratory controlled environmental
conditions to match the in situ conditions at a disposal site for accurate Kd
assessment, Seitz, et al., (18), in recent column infiltration studies of
cesium and other radionuclides on shales and other rock types, has warned of
other factors that also influence radionuclide retention. Some of these
factors which may have application to ocean sediment considerations include
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23
[
(a) flow rates and dispersive characteristics, (b) nuclide-bearing colloids
that react slowly with lithic material, (c) migrating clay particles with
adhered radionuelides, (d) chelating of soluble organic compounds, and (e)
effects of coexisting species of radionuclides.
Sediment Source Considerations ,
The sediment deposition is a function of both source area and transport
agencies. Each of these factors are important considerations in any analysis
of the pathway migration of radionuclides from waste drums at the 2800 meter
site as well as in any potential future disposal sites. Examination of the
sediments at the 2800 meter site reflect both their source and processes of
deposition.
Submarine canyons have been cited by several investigators as sediment
traps that funnel terrigenous sand to ocean depths (10, 19,, 20). Stan-ley, et
al., (21) concludes that turbidity currents moving down the canyons release a
considerable portion of their load on the upper and lower continental rise.
Observations and investigations also cited by Emery and Dohupi (10) would
suggest that the terrigenous sand in the sediment at the 2800 meter nuclear
waste site eminates from a source largely from the Hudson Canyon and lesser
amounts by contour currents from the northeast.
That the"terrigenous sand-size sediment at the 2800 meter nuclear waste
site has its origin from nearshore continental shelf sand funneled down the
Hudson Submarine Canyon can be assessed by diagnostic heavy minerals in the
sand fraction. Several heavy mineral provinces and subprovine.es on the
continental shelf of the mid-Atlantic and New England states have been
delineated by several investigators (10, 19, 22-29). The Hudson Canyon
receives the terrigenous sands from the central New Jersey Coast on the south
.(30) and the Long Island coastal region on the north as a result of longshore
currents directed to the New York Bight (Figure 8). This provides a
SSTh^1^^ heaY7-mineral suite that is similar to the adjacent continental
f? M 3 differs from the heavy-mineral suite delivered by canyons draining
the New England coast. This is apparent in the comparison of the
heavy-mineral suite of samples SH15 and SH2 (Table 3). Sample SH15, located
at the base of the continental slope between Atlantis and Block Canyons,
°2n^n» a Sarnet-staurolite ratio that correlates with the characterization
of the New England shelf heavy mineral province reported by Ross (23)
whereas sample SH2 has a higher garnet-straurolite ratio which is correlative
with the heavy mineral province centering about the New York Bight and the
Hudson Canyon (23). Thus the garnet-staurolite ratios of the 2800 meter
nuclear waste site range between 5 and 9 (Table 3) and these values are
typical of the mid-Atlantic province centering about the New York Bight. Such
data correlates with hydrodynamic considerations previously cited and it
suggests the source of the inorganic portion of the sand fraction may be from
the adjacent continental shelf with relatively short transport distance from
the Hudson Canyon to the deposition site.
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24
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25
That the sediment funneled down Wilmington Canyon on the southwest side
of the 2800 meter study area is not transported northeasterly is suggested by
heavy mineral studies by McMaster (26) and Neiheisel (24),'. The sediment source
of terruginous sands transported by turbidity currents in Wilmington Canyon
appears to be from the areas controlled by longshore currents operating along
the mid-New Jersey Coast toward Cape May (30) and from longshore currents
directed north along the Delaware Coast toward Cape Henlopen (31),
(Figure 8). Twitchell, et al., (32) cite evidence that Wilmington Canyon
extended to Delaware Bay and thus the heavy-mineral suite Iwould probably
reflect a mixed New Jersey suite delineated by McMaster (26) and the Delaware
coast suite delineated by Neiheisel (24) in investigations near shore.
Alexander (25) and Kelling, et al (28) in investigations on the outer shelf
also indicate a change in sillimanite and pyroxenes in prpximity to the
Wilmington Canyon. The influence of the Wilmington Canyon terrigenous
sediment is also not apparent at the 2800 meter nuclear waste site for the
heavy mineral assemblage postulated. However, more definitive sampling must
be conducted to better define this southwestern boundary of that portion of
the upper continental rise containing the 2800 meter nuclear waste site.
Investigators in the deep-sea submersible ALVIN have recently provided
further evidence supporting transport of sediment in a southwesterly direction
along the upper continental rise at the 2800 meter nuclear waste site.
Photographs by Rawson and Ryan (2), reveal (a) nuclear waste drums with rust
and sediment on the lee side of drums extending in a southwesterly direction
and (b) 40 cm high Umbella bending in a southwesterly direction in compliance
with bottom currents. Current meters also recorded a westerly direction and
velocities up to lOcm/sec.
Sedimentation Processes Affecting Radionuclide
Distribution in Sediment
The sediment can only be an effective barrier if the nucilear waste drums
are surrounded by the sediment. Leakage from an exposed area, of the drum
would "short circuit" the sediment trap by moving radionuclides directly into
the water column. Thus any consideration of the capability of the sediment at
the site to retain radionuclides must also consider the capability of waste
drum confinement by burial prior to the release of leachate after rupture or
corrosion of the drums. Even if buried, the bioturbation effected by
burrowing organisms may "short circuit" the sediments potential to entrap the
radionuclides by the sorption process.
The 2800 meter site contains nuclear waste drums were deposited on the
ocean floor a few decades ago and early indications are that relatively few of
the drums have ruptured or corroded excessively. The sedimentation rate at
the site according to Rawson and Ryan (2), is 6.8 cm per 1000 years for the
recent Epoch, i.e., for the last 11,000 years. Thus the amount of sediment
accumulation around the drums is a result of the drum sinking into the soft
sediment, the vertical "blanketing" by sediment from above and the deposition
effected in "craig and tail" like deposits on the leeward side of the drum as
a result of prevailing bottom contour currents. Any meaningful radiological
survey of the fate of radionuclides leached from ruptured waste drums at the
2800 meter site must consider the retention of radionuclides 'by sorption as
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26
well as the potential dispersal by "short circuit" mechanisms such as
bioturbation hydrodinamic mechanisms or direct contact with the water column.
Preliminary surveys by Dayal, et al. (14) from radiometric measurements of
cores taken in 1975 in proximity to waste drums suggest that concentrations of
both eesium-137 and cesium-134 reflect release from nearby waste drums. A
model developed to'describe the observed radioactive cesium distribution,
indicates a faster mixing rate through the vertical than is considered
possible by migration of the radionuclide via molecular diffusion, through
pore waters; an eddy diffusion process is suggested that may relate to
bioturbation, hydrodynamic mechansms, or other short circuit mechanisms.
Summary and Conclusions
The sediment from the 2800 meter Atlantic nuclear waste disposal site and
vicinity has been analyzed for texture, mineral composition, physical
parameters, and geochemical parameters to gain basic information as relates to
the ability of the sediment to act as a barrier to the migration of
radionuclides from the nuclear waste drums.
The texture of the sediment is uniform throughout the waste site to 30 cm
depth and is predominantly a clayey-silt with minor amounts of silty-clay.
The sand-size fraction comprises from 2 to 14 percent of the sediment and
consists predominantly of biogenous calcareous foraminifera tests and minor
amounts of quartz, feldspar, mica, glauconite, diatoms, and detrital heavy
minerals. The predominant silt fraction (42 to 76 percent) consists of
biogenous carbonate (foraminifera, coccoliths and minor other) and detrital
terrigenous quartz, feldspar, mica, and minor other. The clay size fraction
consists of a clay mineral-suite and biogenous carbonate (largely
coccoliths). The clay mineral-suite, comprising 65 to 78 percent of the
clay-size fraction, is comprised of illite (50-57 percent), kaolinite (16-30
percent), chlorite (12-21 percent), and montmorillonite (5-12 percent).
The total cation exchange capacity of the sediment ranges between 15.2
and 25.2 percent with no apparent variation with depth. The exchangeable
cations in order of abundance are Na+, Mg ++, Ca++, and K*. The
relatively high cation exchange capacity of the sediment predicts relatively
high coefficient distribution, (Kd), values to be expected in the sediment.
Bulk specific gravity and porosity values determined for the sediment samples
can be used to compute the radionuclide retention, (Rd), of the sediment if
the distribution coefficient is known. Comparisons of marine sediment Kd's
and terrigenous samples suggest that highest radionuclide retention occurs in
the marine sediments.
The deposition at the waste site is controlled by the vertical "rain" of
micro fossils, contour current movement of sediment in a southerly direction,
and some movement of sediment down the slope'by the effects of downslope
movement or other mechanisms. That the terrigenous sand and silt fraction is
largely controlled by sediment funneled down the submarine canyons with
"plumes" of this sediment made available for directional transport by
prevailing bottom currents is evident in the heavy-mineral suite at the site.
The heavy-mineral suit is typical of the provinance of the New York Bight at
the head of Hudson Canyon and the areas controlled by longshore currents
operating along the coast.
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The ability of the nuclear waste drums to be covered by sediment is
essential if the sediment is to act as a "trap" for the radionuclideg.
Exposed waste drums effect dispersal of the radioactive leaphate to the water
column. Short circuiting of the sediment "trap" may also be effected by
bioturbation or other disturbances of the sediment and migration will be
effected by the pH, Eh, and other environmental factors.
i -
i
Acknowledgements J
This work was sponsored by the Environmental Protection Agency, Office of
Radiation Programs, pursuant to the Marine Protection Research Sanctuaries Act
of 1972, as amended (Public Law 92-532) with R.S. Dyer project officer.
Laboratory equipment to perform sediment analysis was provided the writer by
the U. S. Army Corps of Engineers, South Atlantic Division Laboratory,
Marietta, Georgia under an interagency agreement. Supporting tests, including
grain size distribution curves, porosity, bulk specific gravity, and Atterberg
Limits, were performed by the Corps of Engineers and scanning electron
micrographs were obtained by sub contractual agreement with the Georgia Tech
Engineering Experiment Station. 'Cation exchange capacity analysis were made
by Dr. Kevin Beck of the School of Geophysical Sciences at Georgia Tech.
Special thanks is extended to Dr. Eric Force, U.S. Geological Survey, Reston,
Va, for use of laboratory facilities and petrographic microscope for the
examination of heavy mineral, and to Dr. Robert Carney of the Smithsonian
Institute, for verification of microfauna on scanning electron micrographs. I
also wish to thank Dr. Charles Weaverj of Georgia Tech, Dr. Kenneth Czyscinski
of Brookhaven National Laboratory, and Dr. Alexander Williams of the
Environmental Protection Agency for their careful review and helpful
suggestions in the preparation of this'report.
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-281-147/141!
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