^^

^ The Clinch River Study an 

Investigation of the Fate of

Radionuclides Released 

to a Surface Stream

 Ml

GEOLOGICAL SURVEY 

CIRCULAR 497

Prepared in cooperation with Oak Ridge National Laboratory and the U.S. Atomic Energy Commission
The Clinch River Study an Investigation

of the Fate of Radionuclides Released 

to a Surface Stream

By R. J. Pickering, P. H. Carrigan, Jr., and F. L. Parker

Prepared in cooperation wifh Oak Ridge National Laboratory 

and the U.S. Atomic Energy Commission

Geological Survey Circular 497

Washington 1965
United States Department of the Interior

STEWART L. UDALL, SECRETARY

Geological Survey

THOMAS B. NOLAN, DIRECTOR

Free on application fo the U.S. Geological Survey, Washington, O. C 20242
A b st ract __________________________

Introduction _______________________

Aquatic biology and safety evaluation 

E ydraulic studies __________________

CONTENTS

ater sampling and analysis

Page 

1

1

2

2

2

Page 

Bottom-sediment sampling and

analysis __________________________ 7

Status of the Clinch River Study_______ 10

References ________________________ 12

ILLUSTRATIONS

Figure 1. Map of the lower Clinch River._________________

2. Reduction of maximum concentration of gold-198. 

3 6. Cumulative load in the Clinch River water of 

3. Ruthenium-106___________________________

4. Cesium-137 _____________________________

5. Cobalt-60 ________________________.

6. Strontium-90 _______________________>___.

7. Diagram of analysis of bottom-sediment cores--.

8. Diagram of core scanner ______________________

9. Cross section at Clinch River mile 7.5_________.

Page 

IV

4

5

6

7

9

10

11

Table

TABLES

1. Water-sampling stations, Clinch River Study.

2. Radionuclide loads in Clinch River water___.

3. Concentrations of specific radionuclides ___.

Page 

3 

5 

8

III
84°37'30" 84°30' 84°22'30" 84°15' 84°07'30" 84°00'

Mile 5 upstream from mouth of river

Water sampling station (No2)

10 1234567 MILES

84°37'30" 84°30' 84°22'30" 84°15' 84°07'30" 

Figure 1. Water-sampling stations in the lower Clinch River basin.

84°00'

IV
The Clinch River Study an Investigation of the Fate of 

Radionuclides Released to a Surface Stream

By R. J. Pickering, P. H. Carrigan, Jr., and F. L. Parker 1

ABSTRACT

The Clinch River Study is a multiagency effort to evaluate 

the physical, chemical, and biological effects of the release to 

the Clinch River of low-level radioactive wastes from the Oak 

Ridge National Laboratory. The major radionuclides released 

are ruthenium 106, cesium-137, cobalt-60, and strontium-90. 

t ydrologic and biologic studies have indicated that the radiat on dosages in the river are well below maximum acceptable 

levels. Radionuclide concentrations in river water have been 

measured at seven sampling stations on the Clinch and Tennessee Rivers. Mass-balance calculations for 44 weeks of 

sampling indicate that losses of radionuclides from the water 

phase to the river-bottom sediments represent only a very 

small part of the total radioactivity released to the river.

A study of the Clinch River bottom-sediment cores collected 

1962 has disclosed a recurring pattern of variation in radiotivity with depth which may reflect past events in wastesposal operations at the laboratory. Current investigations 

e expected to provide information about the chemical forms 

which the major radionuclides exist and the mechanisms by 

lich they were incorporated in the sediments.

INTRODUCTION

The Clinch River Study is a multiagency 

effort to evaluate the physical, chemical, and 

biological effects caused by the disposal in 

he Clinch River of low-level radioactive 

vastes from the Oak Ridge National Laboraory2 at Oak Ridge, Tenn. The study, begun 

n 1959, has the following objectives:

1. To determine the fate of the radioactive 

materials currently being discharged to the 

iver.

2. To determine and understand the mechnisms of dispersion of radionuciides reeased to the river.

3. To evaluate the direct and indirect haj;ards of current disposal practices in the 

iver.

*R. J. Pickering and P. H. Carrigan, Jr., U.S. Geological 

urvey, and F. L. Parker, Oak Ridge National Laboratory.

z Operated by Union Carbide Corp. for the U. S. Atomic Energy 

Commission.

4. To evaluate the overall usefulness of 

this river for radioactive-waste-disposal 

purposes.

5. To recommend long-term monitoring 

procedures.

The study is under the general supervision 

of a steering committee composed of representatives of the Oak Ridge National Laboratory (ORNL), the Tennessee State Department 

of Public Health (TDPH), the Tennessee State 

Game and Fish Commission (TGFC), the 

Tennessee Valley Authority (TVA), the U.S. 

Atomic Energy Commission (AEC), the U.S. 

Geological Survey (USGS), and the U.S. Public 

Health Service (USPHS) (Morton, 1961). Investigations are carried out by personnel of 

the various agencies under the direction of 

four subcommittees of the steering committee, namely: Aquatic Biology, Safety Evaluation, Water Sampling and Analysis, and Bottom Sediment Sampling and Analysis.

The Clinch River heads in Virginia and 

flows southwestward to join the Tennessee 

River at Kingston, Tenn. (fig. 1). At its 

mouth the drainage area of the Clinch River 

is 4,413 square miles. At the farthest downstream gaging station, 39.0 miles upstream 

from its mouth, the average flow of the Clinch 

River is 4,612 cfs (cubic feet per second), 

based on a 26-year period of measurement.

During the first 3 years of the Clinch River 

Study, Norris Dam, at mile 7 9.8 on the Clinch 

River (CRM 3 79.8) was the only major control structure on the river. Releases from

3 The abbreviation "CRM" (Clinch River Mile) followed by a 

number has been used in this report to designate distance upstream, in miles, from the mouth of the river. This terminology 

is consistent with prior usage in the Clinch River Study (Morton, 

1961).
CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM

Norris Reservoir are largely made on the 

basis of demand for electric power. In May 

196 3 control of flow began at Melton Hill Dam 

which is at CRM 23.1 on the Clinch River, 

2.3 miles upstream from the mouth of Whiteoak Creek, where radioactive waste from 

ORNL enters the river. The Melton Hill system is to be a "peaking" powerplant, which is 

one that is operated mainly during periods of 

peak demand for power and shut down at 

other times.

The Clinch River below Whiteoak Creek is 

affected by backwater from Watts Bar Dam, 

which is on the Tennessee River 37.8 miles 

downstream from the mouth of the Clinch 

River and a total of 58.6 miles downstream 

from the mouth of Whiteoak Creek. Before 

construction of Melton Hill Dam, thermally 

stratified flow occurred in the lower Clinch 

River from spring to fall because the cold 

water released from Norris Reservoir flowed 

under the relatively still, warmed backwater 

of Watts Bar Reservoir. The effect of the 

operation of Melton Hill Dam on temperature 

conditions in the river is not yet known.

Since 1943, low-level radioactive wastes 

derived from the Laboratory's Process Waste 

Water Treatment Plant, solid-waste burial 

grounds, liquid-waste seepage pits, and other 

minor sources of radioactivity have entered 

the Clinch River through Whiteoak Creek 

(fig. 1). The radionuclides in the wastes are 

largely fission products cesium-137, strontium-89 and 90, ruthenium-103 and 106, and 

others but also include some activation 

products, such as cobalt-60 and zinc-65. 

Continous monitoring of radionuclide concentrations at the point of release to the river 

and downstream at CRM 4.5 has shown that 

concentrations are well within the limits recommended by the National Committee on Radiation Protection.

Whiteoak Creek drains an area of 6 square 

miles, which includes the Laboratory area. 

Its average discharge is about 10 cfs, most 

of which is derived from surface runoff. At 

the present time, its waters are impounded 

in Whiteoak Lake by Whiteoak Dam, which is 

downstream from all sources of radioactive 

wastes and 0.6 mile upstream from the Clinch 

River. The area covered by Whiteoak Lake 

at the present elevation of the gates, 744 feet 

above mean sea level, is 19.1 acres. The use 

of Whiteoak Lake for impoundment of radioactive-waste water was described in more 

detail by Morton (1961).

AQUATIC BIOLOGY AND SAFETY EVALUATION

The radionuclide content of plant and animal life in the Clinch River has been studied 

by the Ecology Section, Health Physics Division, ORNL, and the Radiological Health Research Activities Group, Radiological Health 

Division, USPHS. All preliminary estimates 

of public consumption of fish, ingestion of 

water, and exposure due to use of the river 

for recreational purposes indicated radiation 

dosages that were below maximum permissible levels. Calculation of estimated future 

dose rates is continuing. Results of the biological studies were reported by Morton 

(1961, .1962a, 1962b, 1963).

HYDRAULIC STUDIES

The capacity of the Clinch River to disperse radioactive materials has been assessed through a series of hydraulic testa 

Radioactive gold-198 was used as a tracer in 

the early tests, whereas rhodamine-B and 

pontacyl brilliant pink-B fluorescent dyes 

have been used in more recent tests. In 

these tests, the longitudinal distance downstream to the cross section of complete lateral diffusion, the variation of peak concentration with distance, and the times of travel 

have been determined. Times of water travel 

observed in the tests compare closely with 

times computed on the basis of the continuity 

equation. Nearly uniform lateral mixing occurs within 4 6 miles downstream from the 

mouth of Whiteoak Creek. Variation of concentration with distance is shown in figure 2 

for two of the tracer tests.

WATER SAMPLING AND ANALYSIS

A network of seven water-samp ling stations on the Clinch and Tennessee Rivers was 

established under the direction of the Subcommittee on Water Sampling and Analysis. 

Samples were collected regularly at the stations for material-balance studies of the 

radionuclides released to the river system 

and for information on the stable-chemical 

composition of the river water. Station locations are listed in table 1. Water samples 

were composited weekly on the basis of water 

discharge and were analyzed for major and 

minor radioactive- and stable-chemical constituents. Analyses of stable-chemical constituents were made by personnel of the Tennessee Stream Pollution Control Board at 

Nashville, Term., and radiochemical analyses, 

by personnel of the Division of Radiological
WATER SAMPLING AND ANALYSIS

** 

2

1000

500

-200

tr >

O Q

LU 

O

Q 

LU

50

20

10

X

<

o 9.7 curies Au 198 INJECTED IN LINE ACROSS 

MOUTH OF WHITEOAK CREEK (CRM 

20.8) IN PERIOD OF 80 sec. 

WHITEOAK CREEK DISCHARGE 17 cfs 

CLINCH RIVER DISCHARGE 20,200 cfs

 7.5 curies Au 198 INJECTED IN LINE ACROSS 

MOUTH OF WHITEOAK CREEK IN 

PERIOD OF 67 sec . 

WHITEOAK CREEK DISCHARGE 6.7 cfs 

CLINCH RIVER DISCHARGE 7990 cfs

21 17 15 13 11

CLINCH RIVER MILE

Figure 2. Reduction of maximum concentration of gold-198 with distance during two tracer studies in the Clinch River.

Table 1. Water-sampling stations, Clinch River Study

Station 

.v'o.

1

2

3

4

5

6

7

Location

Oak Ridge water-treatment-plant intake...............

Whiteoak Dam ... __ __...___.._._.._ _ ...._.__._...

Centers Ferry ............ _ ....... ............ ..

Loudon, Tenn_.._. _ ......... _ .......... .......

Watts Bar Dam _.___ __ ..... __ ....._._..__...... .

Chickamauga Dam. _..._..__.___._...._._ _ ._._._._.

Oak Ridge Gaseous Diffusion Plant, water-treatmentplant intake.

Stream

Clinch River.....

Whiteoak Creek __

Clinch River. _ _.

Tennessee River.

___ do ______

___ do .........

Clinch River.....

.Stream mile 

(above mouth)

41.5

.6

5.5

591.8

529.9

471.0

14.6
CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM

Health, USPHS, at the Robert A. Taft Sanitary 

Engineering Center, Cincinnati, Ohio. The 

major radionuclides in the Clinch River water are ruthenium-106, cesium-137, cobalt-60, 

and strontium-90. Most of the cesium-137 is 

associated with suspended sediment having a 

.diameter greater than 0.7 micron, whereas 

.the other three radionuclides are associated 

with finer suspended sediment or are dissolved in the water.

The amount, or load, of a given radionuclide 

which passes a sampling point during a short 

period of time can be assumed to be equal to 

the product of the average radionuclide concentration at the sampling point during that 

period of time and the flow of water that 

passes the point during the same period. If 

there were no loss of the radionuclide from 

the Clinch River water as it moved downstream, the load passing the "background"

station at the Oak Ridge water-treatment 

plant at CRM 41.5 plus the load released 

through the Whiteoak Creek sampling station 

at Whiteoak Dam should equal the load passing the sampling station at CRM 5.5 (see 

fig. 1).

The results of mass-balance (load) calculations (table 2; figs. 3, 4, 5, 6) indicate that 

during the study period virtually all the ruthenium-106 in the Clinch River water was 

transported downstream into the Tennessee 

River. A small part of the strontium-90 in 

the river water was apparently lost in 15 

miles of downstream movement. The calculated loads of cesium-137 and cobalt-60, 

which show apparent gains between the point 

of release to the river and the downstream 

sampling station, cannot be considered reliable because most of the reported concentrations of the two nuclides in samples from

1800

CLINCH RIVER MILE 5.5

CLINCH RIVER MILE 41.5 

PLUS WHITEOAK CREEK

0

NOV

25

TIME (weeks) 

MAR I APR I MAY 

1960 1961

Figure 3. Cumulative load of ruthenium-106 in the Clinch River water for a 44-week period.

SEPT
WATER SAMPLING AND ANALYSIS

O

CLINCH RIVER MILE 5.5

CLINCH RIVER MILE 41.5 

PLUS WHITEOAK CREEK

NOV

1960 1961

Figure 4. Cumulative load of cesium-137 in the Clinch River water for a 44-week period.

CRM 5.5 (32 of 44 determined cesium-137 

concentrations and 26 of 44 determined 

cobalt-60 concentrations) were at or below 

the lower limit of detectability for the analytical procedure used. 4 True gains may have 

occurred as a result of local movement of 

bottom sediment or desorption reactions, but 

this cannot be proved or disproved with the 

available data.

Stable-chemical analyses of the Clinch 

River water from the sampling station at the 

Oe.k Ridge water-treatment plant show the 

ws.ter to have an average hardness (as calcium carbonate) of 106 ppm (parts per millien), a dissolved-solids content of 125 ppm, 

an_ a pH of 7.7. The Clinch River water may

be classed as moderately hard. On the basis 

of its chemical composition, which does not 

vary greatly, it may be called a calcium bicarbonate type of water.

Table 2. Cumulative radionuclide loads in the Clinch 

River water for the period November 13, 1960, to 

September 16, 1961

4 Concentrations of ruthenium-106, cesium-137, and cobalt-60 

in ' .Ater samples were determined by gamma-spectrum analysis 

pro x .ammed through a digital computer. Strontium-90 concentrations were determined by wet-chemical separation and beta 

coi.^ting.

Radionuclide

Ruthenium- 106.

Cesium- 137 --.

Cobalt-60 ____.

Strontium- 90 _.

Cumulative load

(curies)

Mile 41.5 

plus Whiteoak Dam

1680

19.9

24.8

27.7

Mile 5.5

1800

24.3

26.3

24.1

Gain or

loss 

(percent)

+ 7

+22

+ 6

-13
CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM

60 (curies) CUMULATIVE LOAD, Co

ro c-» ^.CO Ul

s*

CLINCH RIVER MILE 41.5 

PLUS WHITEOAK CREEK- -^

SZ?

fy

'?

*/

D 5 10 1 

NOV DEC JAN FEB

.** 

/£-'

5 2 

1 

MAR

>''' \

x^

,'"''

^ CLI

^^=*-

ri 

1 

I

r

MCH RIVER

^

\ MILE 5.5

,''" 

*~

0 25 30 35 40 4 

"IME (weeks) 

APR MAY JUNE JULY AUG SEPT

1960 1961

Figure 5. Cumulative load of cobalt-60 in the Clinch River water for a 44-week period.
BOTTOM-SEDIMENT SAMPIJNG AND ANALYSIS

30

25

20

15

10

CLINCH RIVER MILE 41.5 

PLUS WHITEOAK CREEK

o o>

o5

o" 

< O

CUMULATIVE

^i CLINCH RIVER MILE 5.5

bott 

(C2

NOV DEC

10 

JAN

15 20

FEB

25

TIME (weeks)

MAR APR MAY

30

JUNE

35 

JULY

40

AUG

45 

SEPT

1960 1961

Figure 6. Cumulative load of strontium-90 in the Clinch River water for a 44-week period.

BOTTOM-SEDIMENT SAMPLING AND ANALYSIS

Cross-section composite samples, obtained 

from five cross sections in the Clinch River 

downstream from Whiteoak Creek, have 

shovrn the particle-size distribution in the

>m sediments to be 15 20 percent clay 

microns), 50 60 percent silt (2 62 microns), and 25 30 percent sand C>62 microns) 

(Morton, 1962b). The clay-size fraction of the 

sediment is composed largely of vermiculite, 

mics.,5 kaolinite, randomly interstratified 

vermiculite-mica, and fine-grained quartz. 

The sand and silt fractions of the sediment 

are composed almost entirely of quartz. An 

appreciable content of calcium carbonate in 

the sediment has been indicated by indirect 

evidence, but relative concentrations have 

not 3 et been determined.

Thj uptake, or sorption (McBain, 1950), of 

chen-ical constituents from liquid systems by 

natural sediment -forming minerals has been

5 Nc distinction is made here between mica and illite.

investigated extensively during the past several years. Sorption of radionuclides by 

river sediments was studied by Carrittand 

Goodgal (1953), Barker (1958), Jacobs and 

Tamura (1960), and others. The importance 

of radiocesium uptake by the clay minerals 

has been well established, and Tamura and Jacobs (1960) showed that the 2 :l-layer clay minerals having a c spacing of 10 A selectively 

sorb cesium. Tamura (1963) further showed 

that hydrous iron oxides and aluminum 

oxides, which are common minor constituents 

in many sediments, selectively sorb strontium. The well-known fact that certain radionuclide-sorption reactions are reversible 

has been emphasized by Reynolds' (1963) 

description of desorption reactions which 

occur when fresh-water sediments enter a 

radically different chemical environment, 

such as the ocean. Work on radionuclideuptake by river sediments has been summarized by Sayre and others (1963) and by 

Kornegay and others (1963).
8 CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM

Table 3. Concentrations of specific radionucJides in the upper part of the Clinch River bottom sediments

Clinch River 

mile

4. 7. .__..__._.

5.8____--_-__-

6.9__-_-___-_-

8.0. _. __ _____

9.0________-__

10.0 __ _____ __

11.0.__._ __ ___

12.0 __ ________

13.0________ __

14.0___________

14. 6. __________

15.3___________

16.0 __ ________

16.9___________

18.1 ...........

19.5 __ ________

20.8 __ ........

21.6_____ __ ___

22.5___________

Radionuclide concentration (10~2 ^c/kg)

Ruthenium- 1061

1.05 

1.91 

1.43 

4.13 

3.34 

1.81 

4.50 

2.81 

3.12 

1.33 

4.41 

2.16 

.815 

5.99 

2.12 

2.79 

3.90 

2.54 

1.36

Cesium-1371

6.22 

10.6 

7.21 

11.2 

9.95 

7.97 

19.7 

11.9 

17.6 

10.6 

18.1 

9.77 

3.54 

13.2 

16.1 

7.12 

106 

7.03 

2.48

Cobalt- 6 O1

0.788 

1.42 

.995 

1.55 

1.03 

.752 

1.89 

1.24 

1.84 

1.19 

1.85 

.977 

.347 

1.22 

1.29 

.923 

8.32 

.653 

.334

Strontium- 902

0.086 

.194 

.158 

.189 

.171 

.113 

.423 

.212 

.252 

.194 

.347 

.149 

.077 

.140 

.230 

.108 

1.68 

.144 

.009

TRE 2 3

0.99 

2.28 

1.30 

4.86 

4.42 

2.14 

7.03 

5.40 

7.66 

2.90 

5.63 

3.11 

1.50 

5.86 

3.59 

2.28 

20.4 

3.07 

1.40

i-spectrometer analysis. 

2Chemically separated before counting. 

3 Trivalent rare earths plus yttrium-90.

Surveys of radioactivity in the Clinch River 

bottom sediments have been conducted annually since 1951 by the Applied Health Physics 

Section of the Health Physics Division, ORNL, 

and have indicated that a part of the radionuclides released to the river has been retained 

in the bottom sediments (Garner and Kochtitzky, 1956; Cottrell, 1959). Samples collected 

by the Applied Health Physics Section and the 

USPHS and a bottom-sediment-coring program conducted in 1960 by personnel of the 

Radioactive Waste Disposal Research Section 

of the Health Physics Division, ORNL (table 

3), have provided a measure of the content of 

cesium-137, ruthenium-106, cerium-144, zinc65, cobalt-60, zirconium-niobium-9 5, strontium-90, and the trivalent rare earths in the 

upper part of the sediments (Morton, 1962b).

Although material balances computed from 

analyses of water samples indicate that the 

mass of radionuclides in bottom sediments 

represents only a small part of the total 

mass released to the river, physical and 

chemical processes in the river have concentrated the radionuclides in the bottom sediments enough to make them easily measureable. In areas of the river where continuous 

sedimentation has taken place, the sediments 

provide a record of net radionuclide removal 

from river water as it passed downstream 

throughout the period of release from the 

Laboratory.

In the summer of 1962 a comprehensive 

sampling of the Clinch River bottom sediments through the entire thickness of the 

radioactive zone was conducted by personnel 

of the USGS and ORNL. The samples were 

obtained through the use of the Swedish Foil 

Sampler (Pickering, 1965), a device which 

takes undisturbed sediment cores 2-1/2 

inches in diameter. The sampler utilizes a 

piston and thin steel strips (foils) to decrease 

compaction due to friction between the sample tube and the sediment while the core is 

being taken and to prevent loss of core while 

the core tube is being raised to the surface. 

More than 150 cores were obtained at 14 

cross sections on the Clinch River and
BOTTOM-SEDIMENT SAMPLING AND ANALYSIS

Intact Core:

GROSS GAMMA COUNT OF ALL

CORES.

PHOTOGRAPHIC AND VISUAL LOGGING

OF ALL CORES.

GAMMA SPECTRUM OF SELECTED

CORES.

DETAILED PHOTOGRAPHIC LOGGING

OF SELECTED CORES

Longitudinal 

Quarter-Sector

of 

Selected Cores

Longitudinal HalfSector of All Cores

AUTORADIOGRAPH OF 

CUT FACE. 

HALF-CORE THEN RETAINED FOR FUTURE 

USE

cross

lowing

1.

Longitudinal QuarterSector of All Cores

Composite of 

Radioactive Zone:

RADIONUCLIDE ANALYSIS 

SIZE DISTRIBUTION 

MINERALOGY 

EXCHANGE CAPACITY 

FREE CaC03 

FREE OXIDES 

ORGANIC MATTER

Selected Segments:

RADIONUCLIDE ANALYSIS. 

SEPARATION BY SIZES;

a. MINERALOGY OF EACH 

SIZE CLASS

b. RADIONUCLIDE CONCENTRATION IN EACH 

SIZE CLASS

c. EXCHANGE CAPACITY OF

EACH SIZE CLASS 

FREE CaC03 . 

FREE OXIDES. 

ORGANIC MATTER. 

AGE DETERMINATION;

a. RADIOCHEMICAL

b. PALYNOLOGICAL ANALYSIS 

RADIONUCLIDE DESORPTION 

CHARACTERISTICS. 

EXTRACTION AND ANALYSIS 

OF INTERSTITIAL WATER. 

SPECIAL CHEMICAL AND 

PHYSICAL SEPARATIONS.

Figure 7. Analysis of bottom-sediment cores.

4

Cor

The

Ft;

cated 

expected 

suff:.

sections on two tributary streams, 

recovery was excellent at most sites, 

longest core obtained was 14 feet long.

ans for processing the cores are indidiagrammatically in figure 7. It is 

that the analyses listed will provide 

cient information to determine the folThe total load of each of the major radionuclides in the Clinch River bottom sediments.

2. The distribution of the major radionuclides in the sediments.

3. The distribution of the various size, 

min jralogical, and organic fractions of the 

sedLnents.

4. The relationships between the distribution of the major radionuclides and the composition of the sediments.

5. The chemical form of each of the major 

radionuclides in the sediments.

Determination of the total load of radionuclides in the Clinch River bottom sediments, 

when compared with total releases to the rir 

ver from Whiteoak Creek since 1943 (14,000 

curies), will permit a quantitative estimate 

of the effectiveness of the sediments in 

removing radionuclides from the river water. 

It will also provide a check on materialbalance calculations based on analyses of 

water samples. The other determinations 

listed in figure 7 are directed primarily toward an understanding of the mechanisms by 

which the radionuclides were incorporated in 

the sediments. Sorption, particle sedimentation, and chemical precipitation were probably the principal mechanisms involved.

The lower limit of the radioactive zone and 

the vertical distribution of gross gamma 

radioactivity in the cores collected in 1962 

have been determined by scanning each intact 

core with a device known as a core scanner 

(fig. 8). The core scanner consists of a 3x3-
10 CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM

3 x 3-in. Nal CRYSTAL

AND 

PHOTOMULTIPLIER TUBE^

4-in. lead 

SHIELDING

MULTICHANNEL 

ANALYZER 

AND PUNCH

TAPE READOUT

SCALER

AND PRINTED

TAPE READOUT

^STEPPING PULLEY 

MECHANISM

CORE IN 

PLASTIC TUBE

-STEPPING INTERVAL 

CONTROL

Figure 8. Care scanner.

V 2x2x 2-in. 

COLLIMATOR

inch sodium iodide scintillation crystal and 

matched phototube enclosed in a 4-inch-thick 

cylindrical lead shield. A collimating opening 

2x2x2 inches, leads from the core "well" to 

the scintillation crystal. A calibrated hoist 

automatically moves the core vertically past 

the collimator in 2-inch increments. The 

phototube output can be routed either through 

a sealer for determination of gross gamma 

radioactivity or to a multichannel analyzer 

for determination of the concentration of 

individual gamma-emitting radionuclides in 

each increment.

 Results of gross gamma scanning of cores 

from CRM 7.5 are shown in figure 9. In the 

cross section note the distribution of the 

radioactive sediments and the recurring 

pattern of gross gamma activity with depth in 

several of the cores. The results of visual 

logging and the determination of the vertical 

distribution of individual radionuclides in 

selected cores are hoped to provide information which can be used to correlate specific 

sediment horizons in some of the cores with 

specific past events in waste disposal operations at the Laboratory. The existence of 

other "dateable" physical or chemical properties of the sediments will also be investigated.

STATUS OF THE CLINCH RIVER STUDY

Since the Clinch River Study was initiated 

in 1959, considerable progress has been 

made toward meeting the objectives listed in 

the introduction of this paper. Materialbalance studies have shown that most of the

radioactivity discharged to the Clinch River 

is transported downstream in the Clinch and 

Tennessee Rivers in the water phase. Very 

low radionuclide concentrations in the lower 

Tennessee River make detection farther 

downstream impractical. A small percentage of the radioactivity has been incorporated in bottom sediments of the two rivers. 

A part of the radioactivity in both the water 

and bottom sediments is associated with 

organic matter.

Time-of-travel and dispersion studies have 

outlined some of the hydrologic characteristics of the Clinch River which affect the 

concentration of radioactive waste passing 

downstream points. A few additional tests 

after power releases begin at Melton Hill 

Dam will satisfactorily complete this phase 

of the study.

Laboratory and field studies have indicated 

that cesium-137 is introduced to the river 

and transported largely as a sorbed ion on 

clay-mineral particles. Because this particular sorption reaction is not readily reversible under fresh-water conditons, the incorporation of cesium in river-bottom sediments 

is probably controlled largely by sedimentation processes. Results of desorption, exchange capacity, and other tests being performed on Clinch River bottom-sediment 

samples will provide further information on 

the chemical form of the other radionuclides 

in the sediments and on the overall usefulness 

of the river for disposal of radioactive wastes.
I U104)

STATUS OF THE CLINCH RIVER STUDY 11

Figure 9. Cross section at CRM 7. 5 showing penetration, recovery, and gross-gamma-radioactivily variations with depth for 1962 bottomsediment core samples (vertical exaggeration, 10:1). Cps, counts per second; cpm, counts per minute.

SEDIMENT SURFACE ACTIVITY

GROSS y ACTIVITY 

OF CORE

100 200 300 400 500 

DISTANCE FROM LEFT BANK (ft)

600 700 800
12 CLINCH RIVER STUDY RADIONUCLIDES RELEASED TO A SURFACE STREAM

REFERENCES

Barker, F. B., 1958, Factors affecting the 

transport of radioactivity by water: Am. 

Water Works Assoc. Jour., v. 50,p. 603 

6l'2.

Carritt, D. E., and Goodgal, S. H., 1953, The 

sorptive and zeolitic properties of natural 

and waterborne silts, with relation to their 

capacities to remove, transport, concentrate, and regenerate radioactive \vraste 

components in natural waters: Johns Hopkins University, Dept. of Sanit. Eng., NYO 

4591, 97 p.

Cottrell, W. D., 1959, Radioactivity in silt of 

the .Clinch and Tennessee Rivers: Oak 

Ridge Natl. Lab., ORNL-2847, 50 p.

Garner, J. M., and Kochtitzky, O. W., 1956, 

Radioactive sediments in the Tennessee 

River System: Am. Soc. Civil Engrs. 

Proc., Sanit. Eng. Div. Jour., v. 82, SA 4, 

p. 1-20.

Jacobs,D.G., and Tamura, Tsuneo, 1960, The 

mechanism of ion fixation using radioisotope technique: Internat. Cong. Soil Scientists, 7th, Madison, Wis., 1960, Proc.,v. 2 , 

206-214.

Kornegay, B. H., Vaughan, W. A., Jamison, 

D. K., and Morgan, J. M., Jr., eds., 1963, 

Transport of radionuclides in fresh-water 

systems: U.S. Atomic Energy Comm., 

TID-7664, 406 p.

McBain, J.W., 1950, Colloid science: New 

York, D. C. Heath and Co., 450 p.

Morton, R. J., ed., 1961, Status report No. 1 

onClinch River Study: Oak Ridge Natl. Lab., 

ORNL-3119, 81 p.

Morton, R. J., 1962a, Status report No. 2 on

Clinch River Study: Oak Ridge Natl. Lab.,

ORNL-3202, 97 p. 

 1962b, Status report No. 3 on Clinch

River Study: Oak Ridge Natl. Lab.,ORNL3370, 123 p.

1963, Status report No. 4 on Clinch

River Study: Oak Ridge Natl. Lab.,ORNL3409, 115 p.

Pickering, R. J., 1965, Use of the Swedish 

Foil Sampler for taking undisturbed cores 

of river bottom sediments, in Proc. Federal Inter-Agency Sedimentation Conf., 

1963, U.S. Dept. Agr. Misc. Pub. 970.

Reynolds, T. D., 1963, Sorption and release 

of radionuclides by sediments, in Kornegay, 

B. H., and others, eds., Transport of radionuclides in fresh-water systems: U.S. 

Atomic Energy Comm., TID-7664, p. 127- 

144.

Sayre, W. W., Guy, H. P., and Chamberlain, 

A. R., 1963, Uptake and transport of radionuclides by stream sediments: U.S. Geol. 

Survey Prof. Paper 433-A, 35 p.

Tamura, Tsuneo, and Jacobs, D. G., 1960, 

Structural implication of cesium sorption: 

Health Physics, v. 2, p. 391-398.

Tamura, Tsuneo, 1963, Selective ion exchange 

reactions of cesium and strontium by soil 

minerals, in Colloque International sur la 

migration des ions radioactiffes dans les 

sols: Paris, Presses Universitaires de 

France, p. 95-104.

U. S. GOVERNMENT PRINTING OFFICE : 1965 O - 775-361