ORP/EERF 73-2
CONSTRUCTION AND OPERATION OF AN ION EXCHANGE
CARTRIDGE FOR MONITORING RADIONUCLIDES
IN THE ENVIRONMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Radiation Programs
-------
OFFICE OF RADIATION PROGRAMS
EASTERN ENVIRONMENTAL RADIATION FACILITY
TECHNICAL REPORTS
Technical reports of the Eastern Environmental
Radiation Facility are available from the National Technical
Information Service, Springfield, Virginia 22151, when
a PB number is indicated after the title. Microfiche
copies are $0.95; prices for paper copies are indicated
after the PB number. Bulk order prices are available
from NTIS. The PB number should be cited when ordering.
Title
Radiological Survey of Major California
Nuclear Ports (April 1967) (PB 178 728
$6.00)
BRH/SERHL 70-1
RO/EERL 71-1
EERL 71-2
ORP/EERF 73-1
ORP/EERF 73-2
ORP/EERF 73-3
Radiological Survey of Hampton Roads,
Virginia (January 1968) (AD 683 208 $6.00)
Laboratory Examination of a Ruptured 50-mg
Radium Source (May 1970) (PB 191 810 $3.00)
Development of Ion Exchange Processes for
the Removal of Radionuclides from Milk
(January 1971) (PB 198 052 $0.50)
Investigation of Tritiated Luminous
Compounds (June 1971)
Suitability of Glass-Encapsulated CaF2:Mn
Thermoluminescent Dosimeters for Environ-
mental Radiation Surveillance (June 1973)
Construction and Operation of an Ion
Exchange Cartridge for Monitoring Radio-
nuclides in the Environment (June 1973)
Portable Annealer for Thermoluminescent
Dosimeters (June 1973)
-------
ORP/EERF 73-2
CONSTRUCTION AND OPERATION OF AN ION EXCHANGE
CARTRIDGE FOR MONITORING RADIONUCLIDES
IN THE ENVIRONMENT
J. K. Hasuike
S. T. Windham
Eastern Environmental Radiation Facility
P. 0. Box 61
Montgomery, Alabama 36101
June 1973
I \
ENVIRONMENTAL PROTECTION AGENCY
Office of Radiation Programs
Waterside Mall East
401 M Street, S.W.
Washington, D.C. 20460
-------
The mention of commercial products,
their source, or their use in
connection with material reported
herein is not to be construed as
either an actual or implied endorse-
ment of such products by the U. S.
Environmental Protection Agency-
11
-------
FOREWORD
The Eastern Environmental Radiation Facility participates
in the identification of solutions to problem areas as
defined by the Office of Radiation Programs. The Facility
provides laboratory capability for evaluation and assess-
ment of radiation sources through environmental studies
and surveillance and analysis. The EERF provides technical
assistance to the State and local health departments in
their radiological health programs and provides special
laboratory support for EPA Regional Offices and other
federal government agencies as JE:equested. ^ /\ />
iarles R. Porter
Acting Director
Eastern Environmental Radiation Facility
111
-------
CONTENTS
Page
Foreword ii
List of Tables and Figures iv
Introduction 1
Ion Exchange Method of Sampling 2
Description of Equipment 6
Laboratory Results 8
Conclusion 8
References 10
v
-------
TABLES
Page
1. Laboratory tests of cartridges 9
FIGURES
1. Assembled and disassembled column ... .4
2. Details of column with settling chamber. .5
3. Construction details of ion exchange
column 7
Vi
-------
EERF TECHNICAL REPORT ORP/EERF-73-2
CONSTRUCTION AND OPERATION
OF AN ION EXCHANGE CARTRIDGE FOR MONITORING
RADIONUCLIDES IN THE ENVIRONMENT
J. K. Hasuike and S. T. Windham
SUMMARY
The increased emphasis on measuring environmental
levels of radioactivity requires a maximum of sensitivity
in the collection and analysis of samples. Described
below is an ion exchange sampler developed by this
Facility that has proved very useful in monitoring for
low-level radioactive effluents in the environment.
The sampler consists of a compartmentalized ion exchange
column containing a particulate prefilter and cation
and anion resins. After use the prefilter and resin
are gamma analyzed directly and/or processed via chemical
analysis. The column is easy to construct and use, is
inexpensive, and is reusable.
INTRODUCTION
The Atomic Energy Commission (AEC) has the responsi-
bility of regulating radioactive discharges from nuclear
power plants. It is the reactor operators, State health
departments, private contractors, and other groups who
are actually charged with monitoring the environs of
nuclear facilities to ascertain the actual radioactive
contents discharged. In 1970 the AEC published in the
Federal Register amendments which specified that operators
of light-water cooled reactors keep levels of radioactive
effluents released to unrestricted areas as low as
practicable. The AEC's quantitative definition of "as
low as practicable" recommends that for population
groups in uncontrolled areas their maximum exposures
resulting from these effluents be less than approximately
one percent of natural background.
-------
Thus there is an increased need to identify and
quantify low levels of environmental radioactivity with
a minimum commitment of equipment, time and expense.
The Environmental Studies Branch of the Eastern Environ-
mental Radiation Facility designed and developed a
sectional ion exchange sampler which when used with the
technique described by Krieger1, is very effective
in monitoring for low-level radioactive liquid effluents
in the environment.
The sampler has been used extensively in a study
of the long-term buildup of radionuclides in an impounded
lake supplying cooling water to a nuclear power plant1".
Preliminary data to be published later verifies that the
columns are operating successfully. The ion exchange
field method has been employed by others1, but it is
felt that the columns described here far surpass any
others for simplicity, reliability, and efficiency.
ION EXCHANGE METHOD OF SAMPLING
Ion exchange techniques have received rather wide-
spread acceptance as a method of selectively removing
radionuclides from solutions; e.g., separation of iodine
from milk2'3 and_the radioactive decontamination of
water supplies. "* 7
Samuelson has described ion exchange separation
techniques8, and Krieger1 has developed a technique
for selectively collecting and analyzing environmental
levels of radioactive effluents. The equipment discussed
here implements Krieger's technique.
Routine environmental sample analysis involves the
collection and return to the laboratory of large sample
volumes to obtain adequately low detection capabilities.
By using the field ion exchange method, it is possible
^Study of the Long-Term Buildup of Radioactivity in
an Impounded Cooling Lake. Being conducted by Nuclear
Facilities Research Branch, Eastern Environmental
Radiation Facility. Results not yet published.
-------
to achieve improved detection sensitivity while at the
same time reducing the size of the sample to be trans-
ported to the laboratory. As a routine field ion
exchange procedure used at the EERF radionuclides are
quantitatively removed from 200 liters (438 pounds) of
water on site and returned to the laboratory on a resin
column weighing 2.3 kg (5 pounds). This reduction in
weight and volume plus increased sensitivity makes it
possible to collect samples at more locations and to
provide data with greater statistical significance.
These ion exchange columns were developed through
laboratory studies and field testing. The column was
designed to satisfy the following criteria:
1. Easy and inexpensive to construct using ordinary
shop tools;
2. Easy to set up and use in the field;
3. Easy to process in the laboratory;
4. Provide an efficient means of collecting
radionuclides from water.
The column shown in figure 1 consists of several separate
compartments. The number and size of the compartments
are determined by the requirements of the particular
situation. The one shown has three compartments for
resin plus a glass wool prefliter. The prefliter removes
coarse suspended materials which would clog the resin.
The top resin compartment contains 300 ml of Dowex 50W-X8
cation resin; the center resin compartment contains 300 ml
of Dowex 2-X8 anion resin; and the bottom compartment
contains 300 ml of Dowex 50W-X8 cation resin. The
bottom compartment of cation resin is a backup or safety
section and would collect the radionuclides should they
not be quantitatively removed by the upper cation resin.
The compartmentalized design makes the column very
versatile to fit varied field requirements. For example,
in waters containing large amounts of suspended materials,
it is essential that these materials be removed prior
to entering the resin beds. A settling chamber was
incorporated on top of the column which solved this
problem, (figure 2)
-------
Column assembled for use
Components of disassembled column
Figure 1. Assembled and disassembled column
-------
Column with settling chamber attached
mater (low
r plate -
-{/, vent holes (4)
•(i holes(6)
-6 PVC pipe
-3 O.D. plexiglass
baffle
yss^^^i R^:^S^^
*
11=4!
f
I PVC pipe
I FPT
resin
*\fc XSrXG*
S plenglass
^ to dia. holes (4)
3 O.D. "0"ring.'/i thick
Construction diagram of settling chamber
Figure 2. Details of column with settling chamber.
-------
DESCRIPTION OF EQUIPMENT
The column, as shown in figure 3, is constructed of
materials which are commercially available. Plexiglas
tubing with a 3-inch outside diameter and 2 3/4-inch
inside diameter is used. Pieces of 1/2-inch Plexiglas
are used as the flanges to join the sections of the
column. Figure 3 shows the "0" ring seal and the resin-
retaining screen. The columns flow by syphon action
and it is necessary to insure that each compartment
is leakproof to prevent air pockets in the resin. The
"0" ring seal is very effective in assuring a leak-free
system. The resin-retaining screen is 80 mesh stainless
steel screen which is glued in place between rings in
the lower end of each compartment. These screens pre-
vent the resin from mixing, but permit the water to
flow through unimpeded. All Plexiglas to Plexiglas
joints in the columns are made using ethylene dichloride
as the adhesive. The only tools required for construction
are a band saw, a disc sander, and a 1/2-inch drill
press with circle cutting and regular bits.
PREPARATION AND USE OF THE COLUMN
To allow for maximum convenience in the field, each
cartridge is completely prepared and sealed in the
laboratory. The cation resin is converted to the H+ form,
and the anion resin is converted to the OH~ form as
recommended by the manufacturer.9 The resin is then
measured and loaded into the compartments, the compart-
ments are assembled, and each column is backwashed
gently with distilled water and sealed with hose clamps.
At the field sampling site it is only necessary to
set the column on a ring stand or other convenient
support and connect the inlet tube to the water source
to be sampled. Approximately 30 centimeters (12 inches)
of syphon head is required to deliver a suitable flow
rate through the column. The flow rate is set between
300 to 400 ml/minute, and at this flow rate approximately
10 to 11 hours is required to process 200 liters. Once
started, the column is allowed to run overnight with
the outlet hose from the column secured at a position
above the top resin level. This allows for continuous
flow, at the same time preventing the resin from drying
out. After processing the entire sample, the column is
sealed at the inlet and outlet using hose clamps and
returned to the laboratory for analysis.
-------
2 3/4" 0-RINGS
1/8" THICK
RINGS CUT FROM 2 3/4"
PLEXIGLASS
HOLES FOR 1/4" BOLTS
USE WING NUTS
3" O.D. PLEXIGLASS
RESIN RETAINING SCREEN
Figure S. Construction details of ion exchange colwm.
-------
The multi-compartment design of the column expedites
laboratory processing. After the water is drained
from the column it is physically disassembled and the
resin from each compartment is transferred to separate
counting containers. These are directly gamma counted
for activity- If desired, the resin may then be eluted
or stripped using appropriate techniques to permit
chemical separations and analyses for specific isotopes.
LABORATORY RESULTS
Since the ion exchange concept for removing radio-
nuclides from water is a proven method, little emphasis
has been placed on extensive laboratory testing. Instead,
this report deals with equipment development and not
ion exchange procedure. Tests were run with flow rates
of 500 ml/minute to determine if any radioisotope break-
through would occur in the top section of the column.
Table 1 shows results of 3 runs made using water spiked
with strontium-85 and cesium-137. No breakthrough was
observed.
CONCLUSION
The ion exchange sampler described is simple,
reliable, efficient, and inexpensive. It can be easily
constructed and used by most groups conducting environ-
mental radiological surveillance programs.
In addition to sampling for radioactivity, applications
of these columns could be made in marine research, water
pollution studies, and pesticide studies.
-------
Total original
activity in
200 liters1
Glass Wool
Top Cation Resin:
Anion Resin3
Bottom Cation3
Run 1
500 ml/min
"Sr cpm
41,215
168
35,228
0
30
TABLE I
LABORATORY TESTS OF CARTRIDGES
Run 2
ml/min
Run 3
85 500 ml/min
s
22
22
r cpm
,435
NA
,977
0
31
iJ/Cs cpm
13,518
NA
13,725
0
6
Sr cpm
14,950
NA
15,750
0
0
-L-j'Cs cpm
13,518
NA
13,725
0
0
NA - not available
1 Samples were counted in 300 ml solution before addition to 200 L of tap water
2Counted in cottage cheese containers, amount not available
transferred all 300 ml of resin into a container for counting
-------
REFERENCES
(1) H. L. Krieger, G. W. Frishkorn, Evaluation of Ion
Exchange Surveillance Sampler for Analyzing Radioactive
Liquid Effluents. Health Phys: 21: No. 4, 591-5 (Oct
1971).
(2) D. G. Easterly, I. B. Brooks, J. K. Hasuike,
Development of Ion Exchange Processes for the Removal
of Radionuclides from Milk. Eastern Environmental
Radiation Laboratory Report RD/EERL 71-1 (Jan 1971).
(3) G. K. Murthy, J. E. Gilchrist, J. E. Campbell;
Method for Removing Iodine-131 from Milk. J. Dairy
Sci., 45:1066-74 (Sept 1962).
(4) D. C. Lindsten, J. K. Hasuike, A. G. Friend;
Removal of Radioactive Contaminants from a Seminatural
Water Source with U. S. Army Water Purification Equip-
ment. Health Phys., Vol. 11, pp 723-729 (Aug 1965).
(5) D. C. Lindsten et al., Removal of Radioactive
Contaminants from Water with the Corps of Engineers
Mobile Water Purification Unit, Office of Technical
Services; Department of Commerce, Report PB 135996
(1955).
(6) D. C. Lindsten et al., Removal of Nuclear Bomb
Debris, Strontium-90-Yttrium-90 and Cesium-137-Barium-
137 from Water with Corps of Engineers Mobile Water
Treating Equipment, Office of Technical Services,
Department of Commerce, Report PBAD 265585 (1961).
(7) D. C. Lindsten,and R. P. Schmitt, Removal of Chemical,
Biological, and Radiological Contaminants from Water
with Corps of Engineers Field Water Supply Equipment,
Office of Technical Services, Department of Commerce,
Report PBAD 274300 (1961).
(8) 0. Samuelson, Ion Exchanges^ in Analytical Chemistry
John Wiley, New York (1953).
(9) Dowex; Ion Exchange, The Dow Chemical Company,
Midland, Michigan.
U.S. Government Printing Office: 1973 — 743 - 905/7766 Region No. 4
------- |