EPA/600/R-17/035 I February 2017
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
Evaluation of Hydrogel Technologies
for the Decontamination of 137Cs from
Building Material Surface
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EPA/600/R-17/035
February 2017
Evaluation of Hydrogel Technologies
for the Decontamination of 137Cs from
Building Material Surfaces
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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Disclaimer Statement
This work was conducted under the U.S. Department of Defense (DOD) Technical Support Working
Group (TSWG) Task Plan, Number CB.3803-5, with funding provided by U.S. Department of
Defense and the Israel Ministry of Defense. It has been subjected to U.S. Environmental Protection
Agency (EPA) review and has been approved for publication. Note that approval does not signify
that the contents necessarily reflect the views of EPA. Mention of trade names, products, or services
does not convey official EPA approval, endorsement, or recommendation.
Questions concerning this document or its application should be addressed to:
Shannon Serre, Ph.D. Terry Stilman
CBRN Consequence Management Advisory Emergency Response, Removal and
Division Preparedness Branch
Office of Land and Emergency Management U.S. Environmental Protection Agency
U.S. Environmental Protection Agency 61 Forsyth St., SW
Mail Code E343-06
Research Triangle Park, NC 27711
919-541-3817
Atlanta, GA 30303
404-562-8748
w
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Abstract
The U.S. Environmental Protection Agency (EPA) Homeland Security Research Program (HSRP)
strives to help protect human health and the environment from adverse impacts resulting from release
of chemical, biological, or radiological agents. This current research effort was developed to evaluate
intermediate level (between bench-scale and large-scale or wide-area implementation)
decontamination procedures, materials, technologies, and techniques used to remove radioactive
material from different surfaces. In the event of such an incident, application of this technology
would primarily be intended for decontamination of high-value buildings, important infrastructure,
and landmarks. A cost-benefit calculation may occur in other cases. Two radioisotopes were tested:
aqueous salts of cesium-137 (137Cs) and the short half-life simulant to 137Cs, rubidium-86 (86Rb).
The radioisotope technetium-99m (99niTc) was also used for a preliminary test of the experimental
procedures, without full recording of results. Two types of decontamination technology products
were evaluated: DeconGel™, a product of Cellular Bioengineering Inc. (CBI); and EAI Supergel, a
product developed by researchers at Argonne National Laboratory (ANL), and now manufactured
and supplied by Environmental Alternatives, Inc. (EAI) USA. The work was conducted at the
assigned Chemical, Biological, Radiological, and Nuclear (CBRN) Israel Defense Force (IDF) home
front command facility near the town of Ramla and at the Nuclear Research Center Negev (NRCN),
Israel. Experimental setups at the two sites were nearly identical; however, 99mTc and 86Rb were
utilized at the Ramla site, while only 137Cs was utilized at the NRCN site. Results from these tests
indicated similar percent removal values, %R, and operational factors for both 86Rb and 137Cs. This
was predicted based on the similar chemical properties of both elements. These results further
showed that the short half-life radioisotope 86Rb can be used in future experiments to simulate 137Cs.
Results obtained and conclusions drawn from these experiments appear in this report, and are
compared to previous parameters calculated during EPA's experiments on small coupons.
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Table of Contents
DISCLAIMER STATEMENT i
ABSTRACT ii
ACKNOWLEDGMENTS viii
1.0 INTRODUCTION 1
2.0 EXPERIMENTAL DETAILS 3
2.1 Test Program 1 3
2.2 Radionuclides - Test Program 1 4
2.3 Radiation Measurements - Test Program 1 5
2.4 Decontamination Gels - Test Program 1 10
2.5 Test Program 2 12
2.6 Radionuclides - Test Program 2 15
2.7 Radiation Measurements - Test Program 2 15
2.8 Decontamination Gels - Test Program 2 17
3.0 RESULTS 19
3.1 TestPrograml 19
3.2 Test Program 2 26
4.0 DATA QUALITY ASSURANCE 32
4.1 Test Program 1 32
4.2 Test Program 2 34
5.0 SUMMARY OF RESULTS AND DISCUSSION 35
5.1 Test Program 1 35
5.2 TestProgram2 37
6.0 REFERENCES 40
Appendices
Appendix A: Isolation Chamber Specifications
Appendix B: Surface Data
Appendix C: Experimental Timetables
Appendix D: "mTc results
Appendix E: Test Program 1 Results
Appendix F: Test Program 2 Results
iii
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Figures
Figure 2-1. IsoArk decontamination isolation chamber 4
Figure 2-2. Ceramic surface after dividing to 48 subsurface of 0.25 by 0.25 meter each 4
Figure 2-3. RAM-SURF portable contamination meter 6
Figure 2-4. PDS-100G/ID personal radiation detector, connected to a tripod 6
Figure 2-5. PM-11 2" Nal(Tl) scintillation lead shielded detector 7
Figure 2-6. The NRCN signal processor (DSP) connection box 8
Figure 2-7. PM-11 2" Nal(Tl) scintillation detector calibration chart using a "mTc source 9
Figure 2-8. PM-11 2" Nal(Tl) scintillation detector calibration chart using a 60Co source 9
Figure 2-9. A schematic diagram of the DeconGel™ 1120 decontamination process 10
Figure 2-10. The sprayer used to apply the decontamination gel to the surface 12
Figure 2-11. IsoArk decontamination isolation chamber 14
Figure 2-12. Concrete and limestone surfaces after division into 48 subsurfaces of
0.25 by 0.25 meter each 15
Figure 2-13. PM-11 2" Nal(Tl) scintillation lead-shielded detector 16
Figure 2-14. The torque-stirrer used to prepare the EAI Supergel 17
Figure 2-15. The industrial vacuum cleaner used to remove the EAI Supergel 18
Figure 2-16. The sprayer used to apply the decontamination gel to the surface 18
Figure 3-1. Humidity and temperature at the Ramla site (January 11-18, 2015) 20
Figure 3-2. An image-plate picture taken from one of the ceramics surfaces cleaned
by the EAI Supergel, after the first decontamination cycle 22
Figure 3-3. Pictures taken during the gel applying process (DeconGel™ on the left and
EAI Supergel on the right) 23
Figure 3-4. Pictures taken during the gel removing process (DeconGel™ on the left and
EAI Supergel on the right) 24
Figure 3-5. Humidity and temperature at the Ramla site (8-15 November 2015) 27
Figure 3-6. Gel applying process (DeconGel™top and EAI Supergel bottom) 29
Figure 3-7. Gel removing process (DeconGel™ left and EAI Supergel right) 30
Figure 4-1. Ten calibration spectra generated by the 2" Nal(Tl) detector by use of radioisotope
86Rb—obtained inside the isolation chamber 32
Figure 4-2. Results of the calibration process based on the 10 86Rb spectra
depicted on Figure 4-1 33
IV
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Tables
Table 2-1. Activity Per Surface used for Every Radionuclide* 5
Table 3-1. Setup of surfaces inside the chambers and parameters tested at the
Ramla site during the 86Rb set of experiments (January 11-21, 2015) 19
Table 3-2. Average percent removal (%R) values and standard deviations after the first and
second decontamination processes, as calculated for every surface 22
Table 3-3. Operational factors gathered during the Ramla 86Rb test, average values and
standard deviation in parentheses 25
Table 3-4. Setup of surfaces inside the tents and parameters tested at Ramla
during the 86Rb set of experiments (November 8-15, 2015) 26
Table 3-5. Average %Rs and standard deviations (in parentheses) after the first and second
decontamination processes, as calculated for every surface,
gel, and detector type 28
Table 3-6. Average values of operational factors gathered during the Ramla 86Rb test (standard
deviation values are in parentheses) 30
Table 5-1. Average calculated %Rs for the different surfaces and decontamination gels (standard
deviations in parentheses) 35
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Abbreviations/Acronyms
Af
Final activity
Ai
Initial activity
ANL
Argonne National Laboratory
AVR
Average
°C
Degree(s) Celsius
CBI
Cellular Bioengineering, Incorporated
CBRN
Chemical, Biological, Radiological, and Nuclear
Co
Cobalt
cpm
Counts per minute
cps
Counts per second
Cs
Cesium
dB
Decibel
DOD
U.S. Department of Defense
DSP
Digital signal processor
EAI
Environmental Alternatives, Inc., USA
EPA
U.S. Environmental Protection Agency
HEPA
High-Efficiency Particulate Air
hr
Hour(s)
HSRP
Homeland Security Research Program
IAEC
Israel Atomic Energy Commission
IDF
Israel Defense Force
keV
Kiloelectron volt(s)
kg
Kilogram(s)
L
Liter(s)
lb
Pound(s)
m
Meter(s)
|iCi
MicroCurie(s)
mCi
MilliCurie(s), 1 mCi = 3.7 x 107 Bq = 3.7 x 107 dps
min
Minute
min/m2
Minutes per square meter
mL
Milliliter(s)
mm
Millimeter
MOD
Ministry Of Defense (Israel)
MPa
Mega Pascal(s)
NH4CI
Ammonium chloride
Nal(Tl)
Sodium iodide with thallium activator (a crystal used as an alkali halide
scintillation detector)
NRCN
Nuclear Research Center Negev (Israel)
Pa
Pascal
ppm
Parts per million
psi
Pounds per square in
%R
Percent removal
RDD
Radiological dispersal device
RH
Relative humidity
Rb
Rubidium
VI
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Tc Technetium
TSWG U.S. DOD Technical Support Working Group
VAC Voltage, alternating current (AC) power
Vll
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Acknowledgments
This work was conducted under U.S. DOD Technical Support Working Group (TSWG) task
plan number CB.3803-5. The authors of this report would like to thank Israel Ministry of
Defense (MOD), Israel Atomic Energy Commission (IAEC) - Nuclear Research Center Negev
(Israel) (NRCN), and TSWG for financially supporting this project. Thanks go to Christina
Baxter from TSWG and to Esther Krasner from Israel MOD for guidance and support during
initiation and performance of the task plan. Last but not least, special thanks go to the
professional staff of NRCN's decontamination and radiation safety departments, Argonne
National Lab (ANL), and Tetra Tech, Inc. (Tetra Tech), a contractor with the U.S.
Environmental Protection Agency (EPA). This work would not have been possible without their
commitment to this project.
For IAEC-NRCN
- Ilan Yaar, Ph.D.
- Itzhak Halevy, Ph.D.
- Noah Vainblat
- Maor Assulin
- Tzipora Avraham
- Ronen Bar-Ziv, Ph.D.
- Sharon Anker
- Yacov Iflach, Ph.D.
- Rony Hakmon (Project Manager)
For ANL
- Michael D. Kaminski, Ph.D.
Tetra Tech
- Kevin Scott
Vlll
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1.0 Introduction
The U.S. Environmental Protection Agency (EPA) Homeland Security Research Program (HSRP)
strives to help protect human health and the environment from adverse impacts resulting from release
of chemical, biological, or radiological agents. With emphases on decontamination and consequence
management, water infrastructure protection, and threat and consequence assessment, HSRP is
working to develop tools and information that will aid cleanup of chemical or biological
contaminants introduced into buildings or water systems.
The U.S. Department of Defense (DOD) and the Israel Ministry of Defense (MOD) are jointly
engaged in a project to study procedures for cleaning up contaminated areas—primarily high-value
buildings, important infrastructure, and landmarks following a radiological dispersal device (RDD)
event. Results from this project would apply to any wide-area radiological contamination incident.
The project is led by the U.S. DOD Technical Support Working Group (TSWG) and Israel MOD,
with participation of EPA and experts from the Israeli Nuclear Research Center Negev (NRCN).
To prepare for a possible radiological attack, evaluations of the capability to decontaminate critical
infrastructure, such as transportation (Yaar and others 2015), drinking water systems, power,
communications, medical services, and essential government services, are necessary. Currently
available decontamination technologies must be evaluated for performance on a range of surfaces
that might be contaminated following a wide-area incident. This evaluation must go beyond the
bench scale to ascertain whether the tested technologies will be effective.
Despite some commonalities in a typical RDD scenario, regardless of type of radioisotope involved,
each isotope differs in aerosol particle size and distribution after a release (Harper, Musolino, and
Wente 2007) and in bonding strength to the surface examined. Therefore, every isotope exhibits
different properties that directly and significantly affect selection and implementation of the best
performing and safest decontamination material and technique, as demonstrated in tests by EPA and
others. Furthermore, other variables and factors related to radiological dispersion and individual
building construction are significant in determining location, concentration, total volume, and
associated activity levels of contamination, and of course, selected decontamination methods and
materi al s (Drake 2013 c)
A radiological incident can disperse radioactive material over a large geographic area. All surfaces
and environmental media where the dispersed material settles would become contaminated.
Radioactive material could also be deposited on exterior surfaces such as sidewalks, roofs, streets,
sides of buildings, vehicles and equipment, and on interior surfaces via ventilation systems, open
doors and windows, and pedestrian tracking. Surface deposits such as fine particulate matter may be
removed easily or may adhere to surfaces. Loose surface contamination could be resuspended,
transported, and redeposited elsewhere by physical interaction, wind, or precipitation. Moreover,
sanitary or storm sewers can become contaminated by runoff from precipitation, leading to
subsequent contamination of waterways. Contamination can become fixed if bonded to or embedded
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in the affected surface (in pores, cracks, or crevices). This embedded material would be more
difficult to remove but would be less likely to present an ingestion or inhalation hazard unless it
became disturbed or dislodged. The information in this report addresses removable surface
contamination. In the past few years, EPA has evaluated performances of several peelable/strippable
coatings for radioactive material decontamination. The major differences between this test and the
studies conducted previously pertain to size of test surfaces and use of rubidium-86 (86Rb) as a
simulant for cesium-137 (137Cs). Use of larger surfaces (1.5 by 2 meters) allowed for a more
accurate evaluation of the time and effort needed to perform a large-scale decontamination effort.
Use of the short half-life radioisotope 86Rb (18.6 days) instead of the medium half-life radioisotope
137Cs (30 years) allowed the experiment to be conducted outside of a controlled nuclear facility and
evaluation of the use of 86Rb as a simulant to 137Cs for future large-scale decontamination
experiments.
Testing included application of radioactive contamination to surfaces, measurement of radiation
contamination present on surfaces, application and removal of two types of decontamination
technologies (gels), and subsequent measurement of residual contamination to determine efficacy of
each gel for removal of the contamination.
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2.0 Experimental Details
2.1 Test Program 1
The experimental program plan for the initial test at Ramla and NRCN appears in Appendix C. As
shown in Appendix C, parameters tested in both places were the radioisotope type (86Rb or 137Cs),
surface type (concrete or ceramic), decontamination gel type (DeconGel™ 1120 or Environmental
Alternatives, Inc., USA [EAI] Supergel), and time period before application of the gel on the
contaminated surface (48 or 96 hours).
The tests utilized three isolation chambers (two were positioned at the Chemical, Biological,
Radiological, and Nuclear [CBRN] Israel Defense Force [IDF] facility in Ramla, and one was
positioned at NRCN). These chambers were used to establish controlled temperature, relative
humidity (RH), and airflow conditions; and to prevent spread of radioactive contamination outside
the test facilities. Temperature and relative humidity data were acquired by use of the ZICO 9622,
3-in-l Thermometer, Hygrometer & Alarm Clock [ZICO 2016], Measurements were taken
approximately once per hour. All measurements were taken inside the test facility building and not
inside the isolation chambers.
The IsoArk isolation chambers used in this test, depicted on Figure 2-1, were specially designed and
manufactured by Beth-El Industries Ltd (Beth-El Group 2015) for this test. Isolation chamber
specifications are in Appendix A.
Testing surfaces and materials selected for these experiments, concrete and ceramic, are
representative and typical of materials currently used in interiors and exteriors of buildings in terms
of quality, surface characteristics, and structural integrity—and typical of those in industrial and
municipal settings. The concrete and ceramic test surfaces, shown on Figure 2-2, were manufactured
by Tamar Group (Tamar Group 2015) (surface specifications and method of preparation are in
Appendix B). Test surfaces were prepared from the same starting materials, following the same
preparation procedure as described in Appendix B. A total of eight surfaces, each measuring 1.5 by
2 meters and 0.15 meter thick, were used in the experiments. Six surfaces were used at the Ramla site
and two were used at the NRCN site. The surfaces used at NRCN were divided by a small plastic
separator to form four surfaces of 1.5 by 1 meter each, in order to increase the number of parameters
tested. The surfaces were prepared approximately 2 months before the tests, and were allowed to
equilibrate for 6 days under the controlled environmental conditions of the isolation chamber prior to
contamination of the surfaces with 86Rb or 137Cs radionuclide solutions. All the surfaces were
initially divided into 48 subsectional areas of 0.25 by 0.25 meter each that were preliminarily marked
on the surface, as shown on Figure 2-2.
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Figure 2-1. 1 so Ark decontamination isolation chambers
Figure 2-2. Ceramic surface after dividing into 48 subsections of 0.25 by 0.25 meter each
2.2 Radionuclides - Test Program 1
Radioactive 86Rb chloride and 137Cs chloride salts dissolved in water were purchased from a certified
supplier abroad and used without further purification. The Technicium-99 metastable (99mTc)
solution was purchased from ISORAD (Isorad Radiopharmaceutical Division 2015) in Israel. Due
the short half-life of this isotope, the solution was delivered directly to the Ramla experimental site
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on the day of the field test. Total activities of the radioactive solutions applied during the experiment
were 100 milliCuries (mCi) of 99mTc, 100 microCuries (|iCi) of 86Rb, and 40 |iCi of 137Cs.
To generate identical activities, the concentrated radioactive solutions were divided into identical
volumes by use of a micropipette and poured into common household spray bottles containing
300 milliliters (mL) of distilled water per bottle to produce the final solutions used to contaminate the
tested surfaces (a different bottle was prepared for every surface). The activity per surface used for
every radionuclide is listed below in Table 2-1. Radionuclide contaminants were applied to the test
surfaces (three concrete and three ceramic surfaces at Rami a, and two concrete and two ceramic
surfaces at NRCN) at staggered time intervals during the day, according to the experimental
timetables presented in Appendix C.
Table 2-1. Activity Per Surface used for Every Radionuclide
Radionuclide
Site
Number of
surfaces used
Surface size (meters)
Activity per
surface*
99m
Ramla
2"
1.5x2x0.15
50 mCi
86Rb
Ramla
6
1.5x2x0.15
16.7 |iCi
137Cs
NRCN
4
1.5 x 1x0.15"*
10 |iCi
* The listed activity is not corrected for radioactive decay.
** A total of six surfaces were used at the Ramla site. The "mTc surfaces were later reused for the 86Rb test.
*** The surfaces used at NRCN were half the size of those used at the Ramla site.
2.3 Radiation Measurements - Test Program 1
Radiation measurements occurred by use of the Rotem Industries, Ltd. (Rotem) RAM-SURF
portable contamination meter (Rotem 2015), shown on Figure 2-3; the Universal Detection
Technology personal radiation detector PDS-100G/ID (Rotem 2015), shown on Figure 2-4; and a
conventional 2-inch (2") thallium-activated sodium iodide (Nal(Tl)) scintillation PM-11 Detector
(Rotem 2015), shown on Figure 2-5, connected to a laptop via a digital signal processor (DSP)
connection box built by NRCN, shown on Figure 2-6.
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Figure 2-4. PDS-100G/ID personal radiation detector, connected to a tripod
Figure 2-3. RAM-SURF portable contamination meter
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Figure 2-5. PM-11 2" Nal(Tl) scintillation lead-shielded detector
During the surface measurements, the Nal(TI) detector was shielded with 40 millimeters (mm) of
lead from all sides, and with 1 mm of copper from the front. The detector shield was fitted with
wheels, and the collimated detector was positioned inside it at a fixed height of 0.25 meter above the
scanned area, as shown on Figure 2-5. During the surface measurement, the detector was moved to
obtain a detailed map of the surface contamination, according to the 48 individual sub-surfaces of
0.25 by 0.25 meter that were preliminarily marked on the surface, as shown on Figure 2-2.
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Figure 2-6. The NRCN signal processor (DSP) connection box
Before every day of measurements, the shielded Nal(TI) detector was calibrated by use of a
calibration source. Energy calibration of the detector for the 99mTc tests involved use of the
140.51 -kiloelectron-volt (keV) photo peak in the energy spectrum of this isotope, while energy
calibration of the detector for the 86Rb and l37Cs tests involved use of a Cobalt-60 (60Co) source.
Typical calibration spectra of 99mTc and o0Co obtained by this detector at the Ramla site are depicted
on Figure 2-7 and Figure 2-8, respectively (the two measurements were taken independently under
different detector setups).
In one of the experiments, image-plates [Lee and others 2000] were used in an attempt to obtain a
"real" picture of the contamination layout on the surface. While the Nal(Tl) detector measures total
activity of a 0.25 by 0.25 meter area, the image-plates provide a detailed layout of contamination
distribution within this area.
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200 -
a
T3
c
o
O
(L)
C/3
!-h
(L)
c
o
u
100 -
1000
Channel Number
Figure 2-7. PM-11 2" Nal(Tl) scintillation detector calibration chart using a "mTc source
Channel Number
Figure 2-8. PM-11 2" Nal(Tl) scintillation detector calibration chart using a 60Co source
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2.4 Decontamination Gels - Test Program 1
Two gels were used in this test: DeconGel™ was used in one Isolation Chamber, and EAI Supergel
was used in the other.
DeconGel™, a product manufactured by CBI Polymers, Incorporated (CBI) (Honolulu, Hawaii), is a
one-component, water-based, broad-application, peelable, decontamination hydrogel that works by
attracting the contaminant, binding to it physically and/or chemically, and upon curing, mechanically
locking or encapsulating the contaminant in a polymer matrix. DeconGel™ is available in three
versions, or viscosities, each developed for a specific decontamination use on various surfaces and
areas. The compound used in these experiments was the DeconGel™ 1120. This product was
purchased directly from the supplier as a ready-to-use mix without any dilution.
Drying time finally used for the DeconGel™ 1120 was 48 hours (hr) instead of the originally planned
drying time of 24 hr. The longer drying time was necessary due to temperature and humidity
conditions during the experiment. The removal process from the smooth ceramics surfaces was fast
and easy, while more effort and use of sharp tools were necessary to remove the gel from the more
porous concrete surfaces. After removal, the dried sheets of DeconGel™ were packed and disposed
of easily. A schematic diagram of the DeconGel™ 1120 decontamination process appears on
Figure 2-9.
Site Prep
Apply DeconGel
Remove dried
DeconGel
Survey to
determine CPM
Re-survey
surface areas
Contaminate Surface
Area(s) w/ Cs-137 or
Rb-86
Drying Time
lil application - 24 hrs.
2"° application - 48 hrs.
Allow contaminated
surface area(s) to dry
If contamination remains,
reapply DeconGel. If no
contamination remains, trial is
complete
Figure 2-9. A schematic diagram of the DeconGel™ 1120 decontamination process
EAI Supergel, a product manufactured by Environmental Alternatives, Inc. (Clarksburg, Maryland),
is a gel system that can clean 137Cs radioactive contamination from porous structures such as brick
and concrete on vertical surfaces. The system uses engineered nanoparticles and a superabsorbent
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gel to clean buildings and monuments exposed to radioactive materials. Amount of contamination
removed depends on characteristics of the contaminated structure: age, type of material, whether
painted or unpainted, and the radioactive isotope involved.
The EAI Supergel was purchased as a dry powder. Mixing of the powder with purified water
occurred at the site 0.5-1 hour before application of the gel to the surface, per the instructions listed
below (for preparation of 4 liters [L] of gel).
1. Place 214 grams of ammonium chloride (NH4CI) in a container, and fill to 4 L with
deionized water.
2. Slowly add dry gel components (202 grams dry polymers) to the NH4CI solution.
3. Use a torque-stirrer, shown on Figure 2-14, at 600 revolutions per minute (min) to mix until
the entire dry polymer is hydrated.
Contact time for the EAI Supergel was 90 min, and the gel was removed by use of an industrial
vacuum cleaner. The removal process was difficult because after 90 min, some of the gel applied to
the concrete surfaces was found to be partly dry. A change in the contact time to 30 minutes was
made for the second test program.
Both DeconGel™ and EAI Supergel were applied by use of a hand-held power sprayer with a wide
shot tip. No. 531, shown on Figure 2-10. The main electric motor and gel bucket were left out of the
isolation chamber, and a long flexible pipe was used to transfer the gel from the sprayer into the
chamber. Total volume of the system (sprayer and pipe) was 2 L, and the sprayer and pipe were
cleaned with water after every use.
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Figure 2-10. The sprayer used to apply the decontamination gel to the surface
2.5 Test Program 2
The experimental program for the second test at Ramla is described in Appendix C. Test Program 2
was run nearly identical to Test Program 1, except for the following changes:
• Only one radioisotope, 86Rb was used for Phase 2 evaluation as compared to three used
during the Phase 1 evaluation ("Tc, 137Cs, and 86Rb). Findings from Phase 1 of the
experiment demonstrated that 86Rb was an effective surrogate for 137Cs, one of the
objectives of the experiment, and 157Cs was therefore eliminated from Phase 2 of the
experiment.
• All testing and evaluation during Phase/Test 2 occurred in Ramla at the CBRN IDF facility.
No additional testing or evaluation occurred at the NRCN facility.
• Limestone (Jerusalem stone) and marble replaced ceramic as testing surfaces in the
Phase/Test 2 evaluation. This change was made because limestone and marble are more
prevalent building surfaces in Israel and in the United States, and are also considered
higher-value building materials. Construction/fabrication specifications and physical
properties of the limestone and marble test surfaces are in Appendix B.
• Test surfaces were placed in vertical standing positions during the decontamination phase
of Phase 2, as compared to horizontal positioning used in Phase 1. The change was made
because vertical surfaces are more prevalent than horizontal surfaces in an urban
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environment, and the purpose of the experiment was to simulate real-world conditions.
Application of radioactive contaminant to test surfaces, as well as pre-and post-
contamination/ decontamination measurements, occurred while test surfaces were in
horizontal position.
• Because of safety concerns regarding vertical standing test surfaces, the test surfaces for
the Phase 2 evaluation were constructed in a manner to reduce weight. Each operational test
surface had minimum thickness of 25 mm. The surface of interest was mounted on a lighter
weight material to ensure structural integrity.
• Total activity of the 86Rb source used in the Phase 2 testing was increased to 1000 |iCi, as
compared to 100 |iCi in Phase 1. This change was made because of the short half-life
and natural loss of 3.6% of activity per day, elimination of use of 137Cs in this
experiment, and desire to increase the counting rate and reduce the counting statistical
error.
• Dwell time for both decontamination technologies on the Rb-contaminated test surfaces
prior to removal was 10 min for an area measuring 0.5 by 0.5 meter (total of 12 points per
surface), instead of 5 min for an area measuring 0.25 by 0.25 meter in Phase 1.
• Air flow in the isolation chamber was optimized to only slight negativity to avoid drying
the decontamination materials too quickly. Specifications of the IsoArk isolation
chambers are in Appendix A.
• Phase 2 testing and evaluation of the decontamination technologies occurred during the
second week of November 2015, and continued into the third week of November 2015.
The Phase 2 experimental timetable is in Appendix C.
• Thermogravimetric analysis on concrete test surfaces occurred to determine moisture
content of test surfaces (Yaar 2016).
• Concrete test surfaces were cured for about 30 days prior to the start of Phase 2. All
concrete surfaces used in this test had the same curing time.
• The following information and data needed for a qualitative evaluation of the experiment
were acquired: (1) ancillary equipment required, (2) applicability of the decontamination
technology to other contaminants and substrates, (3) estimation of capital and operating
costs incurred (to be completed under separate cover), (4) deployment and operational
data, (5) applicability to irregular surfaces, (6) skilled labor requirement, (7) utilities
requirements, (8) extent of portability, (9) shelf life of media, (10) degree of damage to
the surfaces, (11) waste management including estimated amounts and characteristics of
spent media and rinse water, and (12) any health or safety concerns about use of the
technology.
As shown in Appendix C, parameters tested in the November experiment were the vertical surface
type (concrete, marble, or limestone) and the decontamination gel type (DeconGel™l 120 or EAI
Supergel).
The tests utilized two isolation chambers to establish controlled temperature, RH, and airflow
conditions, and to prevent spread of radioactive contamination outside the test facility. The IsoArk
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decontamination isolation chambers used in this test, depicted on Figures 2-1 and 2-11, were
specially designed and manufactured by Beth-El Industries Ltd (Beth-El Group 2015) for this test.
The concrete and ceramic test surfaces, shown on Figure 2-12, were manufactured by Tamar Group
(specifications are in Appendix B). A total of six surfaces, each 1.5 by 2 meters and 0.15 meter thick,
were used in the experiments. The surfaces had been prepared about 2 months before the tests, and
were allowed to equilibrate for 3 days under the controlled environmental conditions of the isolation
chamber prior to contamination of these surfaces with the 86Rb radionuclide solutions. All the
surfaces were divided into 12 sub-sectional areas of 0.5 by 0.5 meter each that were preliminarily
marked on the surface, as shown on Figure 2-12.
Figure 2-11. IsoArk decontamination isolation chambers
14
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Figure 2-12. Concrete and limestone surfaces after division into 12 subsections of
0.5 by 0.5 meter each
All the surfaces were placed on a specially designed steel stand that allowed adjustment of the
surfaces between horizontal and vertical positions. Surfaces were in the horizontal position during
contamination of the surfaces with the 86Rb solution and measurements of the contamination in all
phases of the experiment. Surfaces were in the vertical position during application and removal of
the decontamination materials, simulating possible building wall surfaces.
2.6 Radionuclides - Test Program 2
Radioactive 86Rb chloride salt dissolved in water was purchased from a certified supplier abroad and
used without further purification. Total source activity used in the experiment was 1 mCi of 86Rb.
The concentrated radioactive solution was divided by use of a micropipette and poured into common
household spray bottles containing 300 mL of di stilled water per bottle to prepare the final solutions
that were used to contaminate the tested surfaces (a different bottle was prepared for every surface).
Total activity used was about 167 uCi per surface. The radionuclide contaminants were applied to
the test surfaces (two concrete, two marble, and two limestone) at staggered time intervals during the
first day of the experiment, according to the experimental timetable presented in Appendix C.
2.7 Radiation Measurements - Test Program 2
Radiation measurements proceeded by use of the Rotem RAM-SURF portable contamination meter
(Rotem 2015), shown on Figure 2-3; the Universal Detection Technology PDS-100G/ID personal
15
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radiation detector, shown on Figure 2-4; and a collimated 2" Nal(Tl) scintillation PM-11 Detector,
shown on Figures 2-5 and 2-13.
Figure 2-13. PM-11 2" Nal(Tl) scintillation lead-shielded detector
During surface measurements, the Nal(TI) detector was shielded with 40-mm-thick lead cylindrically
wrapped around the detector. In addition to the lead shield, 1 mm of copper was placed in front of the
detector to prevent beta and low-energy X-ray radiation from interfering with the gamma
measurements. The lead shield was attached to a designated plastic box, shown on Figure 2-13, and
the Nal(Tl) detector was placed inside the shield. The plastic box was fitted with wheels positioned at
fixed height of 0.25 meter above the scanned area. During the surface measurement, the detector was
moved to obtain a detailed map of the surface contamination, according to the divided 12 individual
sub-surfaces measuring 0.5 by 0.5 meter that were preliminarily marked on the surfaces.
16
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2.8 Decontamination Gels - Test Program 2
Two gels were used in these tests: DeconGelIM was used in one isolation chamber, and EAI
Supergel was used in the other. Refer to Section 2.4 for complete descriptions of each product.
Drying time for the DeconGel™! 120 was 48 hours. Removal of this product from the surfaces used
in this test was difficult, and a sharp tool was needed. After removal, the dried sheets of DeconGel™
were packed and disposed of easily.
Figure 2-14. The torque-stirrer used to prepare the EAI Supergel
Contact time for the EAI Supergel was 30 min, and the gel was removed by use of an industrial
vacuum cleaner, shown on Figure 2-15. A change in contact time was made following Round 1
where a contact time of 90 minutes resulted in gel that had dried on the surface and was difficult to
remove. Removal of the EAI Supergel was easier than removal of the DeconGelI M1120.
17
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Figure 2-15. The industrial vacuum cleaner used to remove the EAI Supergel
Both gels were applied by use of a hand-held power sprayer with a wide shot tip number 531, shown
on Figure 2-16. Refer to Section 2.4 for a complete description of the sprayer application.
Figure 2-16. The sprayer used to apply the decontamination gel to the surface
18
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3.0 Results
3.1 Test Program 1
Results discussed in this section were obtained during the 86Rb test at the Ramla site
(January 11-21, 2015) and during the 137Cs test at NRCN (March 1-12, 2015).
A preliminary test occurred during January 4-8, 2015, a week before the 86Rb test, by use of the
short half-life radioisotope "mTc. This part of the experiment was conducted to estimate the
applicability of the decontamination technology, not to calculate decontamination factors
(percent removal). Nonetheless, some results obtained during the preliminary "mTc test are listed
in Appendix D.
Setup of the surfaces and parameters tested at the Ramla site during the 86Rb set of experiments is
indicated below in Table 3-1. As evident in Table 3-1, every surface was marked with a two-digit
number. The first digit is the tent number, 1 for the tent where DeconGel™ was used and 2 for the
tent where EAI Supergel was used. The second digit is the position of the surface inside the isolation
tent—1 is the surface positioned at the back of the tent, 2 is the surface positioned at the middle of
the tent, and 3 is the surface positioned at the front of the tent close to the entrance.
Tested parameters were:
• Decontamination gel type: DeconGel™ or EAI Supergel
• Surface type: concrete or ceramics
• Time before applying the gel: 48 or 96 hours, following application of the isotope.
Table 3-1. Setup of surfaces inside the chambers and parameters tested at the Ramla site
during the 86Rb set of experiments (January 11-21, 2015))
Isolation Chamber/
Surface
Gel Type
11
12
13
1 / DeconGelTM
Concrete
Ceramics
Ceramics
48 hrs
48 hrs
96 hrs
21
22
23
2 / EAI Supergel
Concrete
Ceramics
Concrete
48 hrs
48 hrs
96 hrs
Humidity and temperature at the Ramla site were controlled by use of a central air-conditioning
system. However, on certain days, because of fast climate changes during the first 2 weeks of
January, the air-conditioning system could not maintain constant humidity and temperature
conditions, as shown on Figure 3-1.
Average values of 20.94 ± 1.04 degrees Celsius (°C) and 43.11 ± 5.27% (± values are standard
deviations) were calculated for temperature and humidity, respectively, during the experiment
19
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time. Results conveyed here were measured at the room close to the isolation chambers; readings
taken inside the chambers from time to time were similar to those.
'E
x
o
o
(D
TO
(D
Q.
E
.CD
60-
55-
50-
45-
40-
35-
24-
23-
22-
21 -
20-
19-
18
January 11
Humidity
~L
i
Avr=43.11(5.27)
i 1 1 ' 1 1 1 ' 1 ' r
Temperature
Avr=20.94(1.04)
i—1—i—'—i—'—i—'—i—'—i—'—i—'—i—'—i—
0 20 40 60 80 100 120 140 160 180
12 13 14 15 18
Time (hr)
Avr = Average
Figure 3-1. Humidity and temperature at the Ramla site (January 11-18, 2015)
The experimental procedure applied at every surface included nine steps: (1) background
measurements; (2) surface contamination with 300 mL of 86Rb solution with an activity of 16.7 |iCi
per surface; (3) 86Rb contamination level measurements; (4) application of the first gel layer (48 or
96 hours after contamination), about 6 L of gel per surface; (5) decontamination process; (6) 86Rb
contamination level measurements after the first decontamination process; (7) application of the
second gel layer;(8) decontamination process; and (9) 86Rb cumulative (first plus second)
contamination level measurements after the second decontamination process.
Depicted in Appendix E are measurement results of steps (1) background, (3) 86Rb contamination
level, (6) 86Rb contamination level after the first decontamination process, and (9) 86Rb value
cumulative contamination level after the second decontamination process.
Calculated percent removals (%R) after the first and second decontamination processes are also
depicted in Appendix E, and on Figures E-2 (surface 12, DeconGel™) and E-4 (surface 21, EAI
Supergel).
20
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All measurements appearing on the figures were taken by use of the Nal(Tl) 2" detector. Only two
surface measurement results obtained in these experiments are plotted in this report because average
percent removal values were calculated from the raw data files and not from these plots. Plotting
more of the same results would not convey to the reader more usable information about the cleaning
process.
Results of the 137Cs test at NRCN are depicted in Appendix E, on Figures E-5 to E-12 for each set of
tested parameters: surface type (concrete or ceramics) and gel type (DeconGel™ or EAI Supergel).
Measurement results of steps (3) contamination level, (6) contamination level after the first
decontamination process, and (9) contamination level after the second decontamination process are
first depicted for all of the four surface-gel combinations. Calculated %Rs after the first and second
decontamination processes are also depicted. All measurements were taken by use of the Nal(Tl) 2"
detector.
Data acquired from every surface at the Rami a site by use of 86Rb and from surfaces at NRCN by use
of 137Cs were corrected according to the radioactive decay of the tested isotope (this correction was
needed only for 86Rb), and were analyzed after reduction of background radiation. To improve the
statistics of counting, the spectra of every four adjacent 0.25 by 0.25 meter measuring points were
integrated into one 0.5 by 0.5 meter result. Overall, 12 measuring points were obtained for every
surface in each step (background, radioisotope contamination level, radioisotope contamination level
after the first decontamination process, and radioisotope contamination level after the second
decontamination process). Average %Rs and their standard deviations after the first and second
decontamination processes, calculated for every surface from these results, are listed in Table 3-2.
The %Rs were calculated by application of the same methodology used in the past by EPA
(Drake 201 la):
%R = (1-Af/Ai) x 100%
Where A; (initial activity) and Af (final activity) are average radiological activities of the surfaces
before and after the decontamination process, respectively, as recorded by the 2" Nal(Tl) gamma
detector.
21
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Table 3-2. Average percent removal (%R) values and standard deviations after the first
and second decontamination processes, as calculated for every surface (%Rs calculated
after the second process are cumulative values calculated from both first and second
process)
Surface
Gel type
Isotope
48 hours
*
96 hours
First Layer
Second
Laver
First
Laver
Second
Layer
Concrete
DeconGel™
86
Rb
24.1 (±4.2)
27.1 (±3.9)
—
—
137
Cs
26.5 (±3.7)
33.9 (±4.6)
—
—
EAI
Supergel
86
Rb
32.3 (±5.9)
44.4 (±7.6)
_
36.3 (±9.3)
59.9 (±12.9)
137
Cs
30.1 (±4.6)
45.8 (±3.7)
—
—
Ceramics
DeconGel™
86
Rb
65.5 (±8.0)
89.9 (±6.0)
82.2 (±4.7)
—
L_
137
Cs
63.5 (±8.3)
80.0 (±3.9)
r
—
—
EAI
Supergel
86
Rb
81.9 (±5.6)
92.0 (±2.3)
—
...
137
Cs
78.1 (±3.9)
r
86.1 (±3.6)
...
...
L
* Each difference in a pair of results (associated with a particular gel type coated on a particular surface) considered
statistically insignificant is marked with yellow background, and each difference in a pair of those results considered
statistically significant is marked with green background. For example, the difference in the pair of average %Rs
obtained from concrete coated with DeconGel™ (first layer) is statistically insignificant (yellow), while the
difference in average %Rs obtained from concrete coated with DeconGel™ (second layer) is statistically significant
(green). Each result in a pair of results derived from use of a specific radioisotope as the source of radiation (86Rb
or 137Cs).
In gamma measurements by use of the 2" Nal(Tl) gamma detector, the detector field of view, and
therefore the measurement special resolution, was limited to an integration over an area of 0.25 by
0.25 meter, with no ability to determine the distribution of contamination inside of the area. In an
attempt to obtain a more detailed contamination distribution map, some image-plates were positioned
at several areas on the contaminated surfaces. The image-plates (Lee and others 2000) were placed
after the first decontamination cycle and were left over the weekend to accumulate the signal. These
plates were taken to NRCN for development.
Figure 3-2. An image-plate picture taken from one of the ceramics surfaces
cleaned by the EAI Supergel, after the first decontamination cycle
22
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One image taken from one of the ceramics surfaces cleaned by the EAI Supergel is shown on Figure
3-2. Dark lines indicate areas of higher radiation levels. These areas, left after cleaning off the EIA
Supergel by use of an industrial vacuum cleaner, are where m ortar was located between the cerami c
tiles, where most of the remaining contamination was concentrated, leaving the tile surface almost
contaminant-free. The other pictures taken by the image-plates, not shown here, showed similar
results. Therefore, this test was not repeated in Phase 2 of the experiment.
Some pictures taken at the Ramla site during gel application and removal processes appear on
Figure 3-3 and Figure 3-4, respectively.
Figure 3-3. Pictures taken during the gel application process (DeconGelI M on the left and
EAI Supergel on the right)
23
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Figure 3-4. Pictures taken during the gel removal process (DeconGelI M on the left and
EAI Supergel on the right)
24
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In addition to the calculated decontamination efficiency values, listed in Table 3-2, some of the
decontamination operational parameters (e.g., time, man power, gel volume, waste volume), were
also measured during the test. Some estimated values of operational aspects of the decontamination
process, calculated from the 86Rb test at Ramla, are listed in Table 3-3.
Table 3-3. Operational factors gathered during the Ramla 86Rb test, average values and
standard deviation in parentheses
Parameter
Concrete
Ceramics
Application time (min/m2)
DeconGel™
3.2 (±0.2)
2.0 (±0.6)
EAI Supergel
4.1 (±1.2)
Total dwell time (hr)
DeconGel™
Minimum of 24-48 for draying (depending
on environmental conditions and surface
type)
EAI Supergel
maximum of 1.5 before removing
Removal time (min/m2)
DeconGel™
2.5 (±0.2)
1.2 (±0.5)
EAI Supergel
5.4 (±1.5)
Gel Volume (liter/m2)
2.7 (±1)
2.0 (±1)
Waste volume (cm3/m2)*
DeconGel™
1440(±38)"
1058(±18)
Notes:
* cm3 of waste per m2 of surface area treated with the DeconGel™. Results for the EAI Supergel were not recorded
because this liquid-like gel was transferred directly from the vacuum cleaner into a Venniculite cask.
** Concrete waste volume was 36% larger than ceramic waste volume because more gel was used on the concrete
surfaces to ease the stripping process from those surfaces.
cm Centimeter
hr Hour
m Meter
min Minute
In addition to the quantifiable operational parameters listed in Table 3-3, some qualitative evaluation
aspects about the work conducted are as follows:
• DeconGel™ proved less suitable for decontamination of textured surfaces such as
concrete, asphalt, or limestone than the EAI Supergel.
• EAI Supergel dried rapidly. Therefore, this gel should be vacuumed no more than 30 min
after spraying it onto the surface. Manufacturer instructions and results obtained by us in
the second test indicate that the shorter time does not significantly influence efficiency of
gel decontamination.
• Preparation of both gels for use is not complicated, with an advantage to the DeconGel™
as a ready-to-use commercial product. Time needed to prepare the EAI Supergel on site
was less than 20 min for 10 L of the gel. This time can be reduced depending on size of
equipment used.
25
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• Because of safety regulations, only experienced and authorized decontamination
personnel participated in the test. However, in a real situation, construction laborers or
tradesmen could conduct decontamination after undergoing a short training.
• Both materials are not toxic and are easy to use.
• DeconGel™ might damage irregular and porous surfaces somewhat, while EAI Supergel
will not. This damage is evidenced by small concrete fragments turned out from the
surface of the concrete during the stripping process (this can be further examined in the
future via an experiment without use of radioactive materials).
• The same instrumentation is needed to apply both materials. Removal of DeconGel™ can
proceed mostly by use of hand tools, while an industrial vacuum cleaner is necessary to
remove EAI Supergel.
3.2 Test Program 2
Results presented in this section were obtained during the 86Rb test at Ramla (November 8-15, 2015).
Setup of surfaces and parameters tested are listed in Table 3-4. The test parameters listed in Table 3-4
are Decontamination gel type (DeconGel™ or Argonne Super Gel), and the surface type (concrete,
marble, or limestone). The first digit is the tent number—1 for the tent where DeconGel™ was used
and 2 for the tent where EAI Supergel was used. The second digit is the position of the surface inside
the isolation tent—1 for the surface positioned at the back of the tent, 2 for the surface positioned in
the middle of the tent, and 3 for the surface positioned at the front of the tent close to the entrance.
Table 3-4. Setup of surfaces inside the isolation chambers and parameters tested at Ramla
during the 86Rb set of experiments (November 8-15, 2015)
Isolation Chamber /
Gel type
Surface number / Type
1 / DeconGel™
11/ Concrete
12 / Marble
13 / Limestone
2 / EAI Supergel
21/ Concrete
22 / Marble
23 / Limestone
Humidity and temperature at the Ramla site were controlled by use of a central air-conditioning
system. Measured values for both parameters are shown on Figure 3-5. Average values of
21.34 ±0.37°C and 60.83 ±7.86% (± values are standard deviations) were calculated for temperature
and humidity, respectively, during the experiment time. Results presented here were obtained at the
center of the experimental hall, close to isolation chambers; readings taken inside the isolation
chambers from time to time indicated similar results.
26
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70
TD
60
h
X
50
40
o
24
?3
L.
22
£5
21
a
20
E
£
19
1—
18
Humidity
Avr= 60.83 (7.86)
Temperature
pfb—.—
A-
Avr= 21.34 (0.37)
—• r~
0 20
November 8
i—•—i—•—i—•—i—•—i—
40 60 80 100 120
9 10 11 12
Time (hr)
140
—i 1 1—
160 180
15
Avr = Average
Figure 3-5. Humidity and temperature at the Ramla site (November 8-15, 2015)
The experimental procedure for every surface according to the experimental test plan included nine
steps: (1) background measurements, (2) surface contamination with 300 mL of 86Rb solution,
(3) 86Rb contamination level measurements, (4) application of the first gel layer containing about 6 L
of gel per surface, (5) first decontamination process, (6) 86Rb contamination level measurements after
the first decontamination process, (7) application of the second gel layer, (8) second decontamination
process, and (9) 86Rb contamination level measurements after the second decontamination process.
Measurement results from every surface at the Ramla site were corrected according to the radioactive
decay of 86Rb and analyzed after reduction of background radiation. Overall, 12 measuring points
were obtained for every surface in each step (background, 86Rb initial contamination level, 86Rb
contamination level after the first decontamination process, and 86Rb contamination level after the
second decontamination process) for each one of the three detectors used (2" Nal(Tl), PDS-100G/ID,
and RAM-SURF). Average %Rs were calculated by application of the same methodology described
in Section 3.1.
Measurement results of steps 3, 6, and 9, as well as calculated %Rs after the first and second
decontamination processes, with Nal(Tl) 2" as the detector, are depicted in Appendix F on Figures
F-l to F-6. Average %Rs after the first and second decontamination processes, with PDS-100G/ID
and RAM-SURF as the detectors, are depicted in Appendix F on Figures F-7 to F-12.
27
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Average %Rs and standard deviations after the first and second decontamination processes, as
calculated for every surface and detector via the equation shown in Section 3.1, are listed in
Table 3-5.
Regarding the gamma measurements by the 2" Nal(Tl) gamma detector, the detector field of view
(and therefore measurement special resolution) was limited to an integration over an area of 0.5 by
0.5 meter. PDS-100G/ID and the RAM-SURF beta/gamma radiations were measured without
collimation.
Table 3-5. Average %Rs and standard deviations (in parentheses) after the first and second
decontamination processes, as calculated for every surface, gel, and detector type
First decontamination process Second decontamination process
Surface
Gel
Nal(Tl)
PDS-
100G/ID
RAM-
SURF
Nal(Tl)
PDS-
100G/ID
RAM-
SURF
Concrete
DeconGel™
8.8 (±4.0)
20.5 (±3.8)
23.9
(±6.6)
13.6 (±3.7)
21.5 (±1.2)
35.0 (±7.7)
(1)
EAI Supergel
32.5 (±8.1)
29.1 (±10.7)
59.9
(±9.5)
42.7 (±7.7)
37.3
(±15.3)
74.5 (±6.1)
Marble
DeconGel™
17.1 (±5.1)
12.3 (±7.2)
36.2
(±18.2)
28.1 (±3.4)
29.6
(±10.0)
55.2 (±9.9)
(2)
EAI Supergel
31.4 (±5.0)
24.4 (±9.6)
42.2
(±7.9)
38.4 (±4.5)
35.3
(±12.5)
67.8 (±3.2)
Limestone
DeconGel™
39.0 (±6.4)
22.1(±12.2)
36.6
(±9.4)
45.2 (±4.4)
36.1 (±8.9)
50.0 (±14.4)
(3)
EAI Supergel
26.4 (±3.7)
28.6 (±11.3)
54.4
(±11.3)
35.2 (±4.9)
34.1 (±7.8)
71.9 (±5.3)
Several important conclusions can be deduced from the results listed in Table 3-5:
• In 15 out of 18 cases, average %R with use of EAI Supergel was larger than that with use
of DeconGel™ by about 17%.
• Cumulative, calculated, average %Rs after the second cleaning process exceeded %Rs
measured after the first cleaning process by averages of about 9% (gamma
measurements) and 17% (beta measurements).
• Average %R calculated from all beta measurements by the RAM-SURF meter was larger
by about 18% and 26% after the first and second cleaning processes, respectively, than
28
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the average %R calculated from all gamma measurements by the 2" Nal(Tl) and PDS-
100G/ID detectors.
Some pictures taken at the Ramla site during the gel application and removal processes are
depicted on Figure 3-6 and Figure 3-7, respectively.
Figure 3-6. Gel application process (DeconGel™ top and EAI Supergel bottom)
29
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Figure 3-7. Gel removal process (DeconGel™ left and EAI Supergel right)
In addition to the average %Rs listed in Table 3-6, operational factors gathered during the
decontamination processes are listed in Table 3.
Table 3-6. Average values of operational factors gathered during the Ramla 86Rb test
(standard deviation values are in parentheses)
Parameter
Concrete
Marble
Limestone
Average
Application time (1st, 2nd)
DeconGel ™
2,4
2.7,4.3
3.7 , 5
3.6 (±1.1)
(min/m2)
EAI Supergel
1.7,1
2,4
1 , 5.3
2.5 (±1.8)
Delay time needed before
DeconGel™
48
removal (hr)
EAI Supergel
0.5
Removal time( 1st, 2nd)
DeconGel™
43*, 4
6.3 , 6
3 , 5.7
5.0 (±1.4)
(min/m2)
EAI Supergel
8.3 ,5
5,6
5.3 , 3.3
4.9 (±1.0)
Gel Volume (liter/m2)
Both gels
2-2.5
Waste volume (cm3/m2)
EAI Supergel
2-2.5 (in the wet phase)
Notes:
* The time period of the first removal by DeconGelTM from surface 1.1 (concrete), marked in red, was much longer
(129 min) than all the other measured time values, and was therefore omitted from calculation of average removal
time.
30
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cm Centimeter
hr Hour
m Meter
min Minute
In addition to the quantifiable parameters listed in Table 3-6, some qualitative evaluation aspects
about the work conducted are as follows:
• DeconGel™ is less suitable for decontamination of textured surfaces like concrete,
asphalt, or limestone.
• EAI Supergel dries rapidly. Therefore, this gel should be vacuumed no more than 30 min
after spraying it on the surface (this time is influenced by temperature and relative
humidity on site).
• Preparation of both gels for use is not complicated, with an advantage to DeconGel™
that comes as a ready-to-use commercial product. Time needed to prepare EAI Supergel
on site was about 20 min for 10 L. This time can be reduced by use of large industrial
mixing equipment.
• Because of safety regulations, only skilled and authorized decontamination personnel
participated in the test. However, in a real situation, unskilled workers could conduct the
decontamination after undergoing a short training.
• Both materials are not toxic and are easy to use.
• DeconGelTM might damage irregular and porous surfaces somewhat. This damage is
evidenced by small concrete fragments turned out from the surface of the concrete during
the stripping process (this can be further investigated in the future via an experiment
without use of radioactive materials).
31
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4.0 Data Quality Assurance
4.1 Test Program 1
The contamination measurement process initially proceeded as planned, by use of all three detectors
(RAM-SURF, PDS-100G/ID, and 2" Nal(Tl)) taking 48 data points (0.25 by 0.25 meter for every
measuring point) from every surface. However, due to the low readings recorded, especially after the
first and second decontamination cycles, only the 2" NaI(Tl) detector readings were found
statistically valid. To strengthen the statistical precision of these measurements, every four adjacent
measurement point readings were integrated into one point representing an area of 0.5 by 0.5 meters,
and resulting in 12 measurement points per surface, with better statistics for every measurement
point.
Preliminary calibration of the 2" Nal(Tl) detector, prior to measurements of radiation from 86Rb and
137Cs, proceeded by use of a low-activity 60Co source. Following that calibration process, performed
outside the isolation chamber, the detector was calibrated inside the chamber by use of 86Rb and
137Cs with references to the 86Rb 1076.64 keV and 137Cs 661.7 keV peaks. A sample of the stability
of this calibration process for the 2" Nal(Tl) detector by reference to the characteristic peak of
radioisotope 86Rb at 1076.64 keV is depicted on Figure 4-1 and Figure 4-2.
250-
200-
200
250
300
350
400
450
Channel Number
Figure 4-1. Ten calibration spectra generated by the 2" Nal(Tl) detector by use of
radioisotope 86Rb—obtained inside the isolation chamber
32
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g 302
E
^ 300
£ 298
j= 296
O
294
250
_ 200
to
CL
O
a, 150
c
=3
O 100
123456789 10
Measurement Number
Figure 4-2. Results of the calibration process based on the 10 86Rb spectra depicted on
Figure 4-1
Results of average %Rs listed in Table 3-5 were tested by application of the statistical unpaired t-test
model, with N=12 and 95% confidence interval of difference for every pair of results, in order to
calculate whether differences in average %Rs resulting from use of 86Rb and 137Cs as sources of
radiation were significant or not. Results of these tests are listed in Table 3-2, where differences
considered insignificant are marked with yellow background, and differences considered significant
are marked with green background.
As evident in Table 3-2, results of the statistical t-test were inconclusive. Three of the pairs were
found statistically different, and five were not found significantly different. Overall average
calculated difference value between the decontamination factors of both isotopes, based on all the
pairs, was -0.8 (±11.8%), regardless of the decontamination gel or surface type. Therefore, it was
concluded that this experiment indicated no statistically significant difference between results based
on use of 86Rb and results based on use of 137Cs. This finding was similar to findings of an
experiment at NRCN in an earlier phase of this program, whereby Rb was tested in a lab setting to
determine if it could serve as a surrogate for Cs in a decontamination setting (Paz and others 2014).
Thus, 86Rb can be considered a good surrogate for 137Cs for the types of materials tested here.
^ o o o o
G © Q O
298.93 (0.27) Ch
1076.64 keV
204.50 (11.96) cps
i 1 1 1 1 1 1 1 1 r
33
-------
4.2 Test Program 2
The contamination measurement process proceeded as planned, with use of all three detectors
(RAM-SURF, PDS-100G/ID, and 2" Nal(Tl)), and 12 measuring points (0.5 by 0.5 meter for every
measuring point) from every surface.
As shown on Figure 3-5, preliminary calibration of the 2" Nal(Tl) detector (before its involvement
with 86Rb measurements) occurred by use of a low-activity 60Co source. After that preliminary
calibration (performed outside the isolation chamber), the detector was calibrated inside the chamber
with use of 86Rb and reference to the 86Rb 1076.64 keV peak.
Average and standard deviation values listed in Tables 3-5 and 3-6 were calculated by use of regular
normal statistical distribution functions. About 6% outliers results found to be more than 4o away
from the calculated average value were omitted from the calculations. Explanation for this large
deviation was not apparent. However, several possible causes include wrong position of the detector
while taking the measurement, a mistake in the manes of one of the files (background, first, or
second measurement), or resuspension of the contamination from one mastered area of 0.5 by
0.5 meter to a neighbor area during the cleaning process.
34
-------
5.0 Summary of Results and Discussion
Results obtained during both tests are presented in this report. The tests occurred in Israel with use of
large surfaces (1.5 by 2 meters) made of concrete, ceramic, marble, and limestone; two types of
decontamination gels (DeconGel™ and Argonne Super Gel); two types of radionuclides (86Rb and
137Cs); and two different time periods before application of the gel on the contaminated surface
(48 hours and 96 hours).
Previous EPA experimental results (Drake 201 la, b; 2013b, e) from work with comparable
decontamination gels yielded %Rs of 67 ± 9%, 35 ± 13%, and 93 ± 0.9% for DeconGel™ 1108
application on concrete, limestone, and marble, respectively; and 73 ± 5%, 16 ± 6.3%, and 71 ±4%
for EAI Supergel application on concrete, limestone, and marble, respectively.
5.1 Test Program 1
From these results, %Rs and some operational parameters were determined for the decontamination
process involving the two radionuclides. This section summarizes these results and the major
conclusions drawn from them, and compares the results to those obtained from previous EPA
experiments with similar decontamination gels on small coupons of 0.15 by 0.15 meter.
Final %R values for the different surfaces and decontamination gels calculated after the second
decontamination process are listed in Table 5-1. As stated in Sections 3 and 4 of this report, no
significant difference was found between %Rs resulting from use of the two radionuclides (86Rb and
137Cs) or between the wait times before application of the decontamination gel to the surface (48 or
96 hours). Two major conclusions can be drawn from the results listed in Table 5-1: first,
decontamination efficiency of EAI Supergel is higher than that of DeconGel™ by about 10%;
second, overall efficiency of decontamination of ceramic surfaces is about twice overall efficiency of
decontamination of concrete surfaces.
Table 5-1. Average calculated %Rs for the different surfaces and decontamination gels
(standard deviations in parentheses). Results are averages from uses of both 86Rb and 137Cs
Decontamination Gel
Gel application
Concrete (%R)
Ceramic (%R)
DeconGel™
First
25 (±3)
70 (±4)
Second"
31(±3)
85 (±4)
Argonne Super Gel
First
33(±4)
80 (±3)
Second"
50 ±(3)
89 (±2)
* Accumulated average calculated %Rs from both decontamination processes
35
-------
Results calculated in this experiment, listed in Table 5-1, were not significantly different from EPA's
previously reported results for concrete and marble (assuming that marble and ceramics have
similar %Rs).
Most operational factors documented during the decontamination process using 86Rb at Ramla (see
Section 3 and Table 3-3) cannot be compared to the parameters documented during earlier EPA
research studies (Drake 201 la, b; 2013b, e). In earlier EPA experiments, gel application to the small
concrete coupons occurred by use of 4-inch paint brushes. This process was relatively slow and took
approximately 25 min/m2 and 40 min/m2 for application and removal, respectively, of one coat of
DeconGel™ 1108 on the concrete coupons; and 60 min/m2 for application and removal of one coat of
EAI Supergel on the same coupons. DeconGel™ 1108 comes as a ready-to-use compound, while the
EAI Supergel requires a preparation time of 15 min for mixing the powders with water. Application
and removal times listed here were calculated based on results presented in the EPA references listed
above.
Comparable application times measured in large-scale (1.5 by 2 meter) tests described in this report
were 3.2 (0.2) min/m2 (number in parentheses is standard deviation) and 2 (0.6) min/m2 for the
comparable one coat of DeconGel™ 1120 on concrete and ceramics, respectively; and
4.1 (1.2) min/m2 for one coat of EAI Supergel on both surfaces (concrete and ceramics). Application
was by use of a professional paint sprayer, depicted on Figures 2-10 and 2-16. Time needed for
mixing the EAI Supergel powders with water was approximately the same (10-15 min). Setup time
for the paint sprayer system was about 15 min, and two skilled workers were needed for its operation.
However, total spraying time with this system was about an order of magnitude lower than the time
needed for a worker using the paint brush in the earlier EPA tests. This system is suitable for small-to-
medium size contaminated surfaces or rooms. A more robust and self-mobile system would be
necessary to decontaminate larger areas, and time required to apply the material this way would
probably be shorter.
Times periods for removals of gels used in this experiment were 2.5 (0.2) min/m2 (number in
parentheses is standard deviation) and 1.2 (0.5) min/m2 for the DeconGel™ on concrete and
ceramics, respectively; and 5.4 (1.5) min/m2 for EAI Supergel on both surfaces. Time needed to
remove the DeconGel™ from the concrete surface was twice the time needed to remove it from the
ceramics surface because of stronger attachment of the gel to the rough texture of the concrete
surface. Again, comparing EPA's small-scale experiment to our large-scale experiment is not
straightforward. Removal of DeconGel™ from the surface occurred via a simple stripping process,
almost regardless of surface size. Removal of EAI Supergel occurred by use of an industrial vacuum
cleaner that was not optimized for this process; some modifications to the sucking head occurred
during the experiment to facilitate the cleaning process. A second factor in EAI Supergel removal
time was the too-long, 90-min wait period before gel removal, affecting its viscosity and causing it to
stick to the surface (especially to the concrete). Shorter waiting time of about 30 min before removal
of this gel from the surface is recommended in future experiments.
36
-------
Volumes of dry DeconGel™ 1120 sheets after removal from the concrete and ceramic surfaces were
1440 (38) cm3/m2 and 1058 cm3/m2 (cm3 of waste per m2 of surface area treated with DeconGel™),
respectively. The comparable volume measured by EPA for DeconGel™ 1108 removed from
concrete coupons was 252 cm3/m2. However, viscosity of new DeconGel™ 1120 gel seems to be
much lower than that of DeconGel™ 1108 gel, and therefore thicker layer of gel was needed to
render it peelable from the concrete surface, resulting in a volumetric increase in waste. Volume of
EAI Supergel generated during the surface decontamination process was not measured in this
experiment, and the material was fixed in vermiculite at the end of every process. A real cleaning
process will require a separate process of drying this gel in a dedicated furnace to decrease its volume
and avoid dealing with a wet radioactive substance.
The overall qualitative evaluation is that DeconGel™ is suitable for decontamination of smooth and
small surfaces, such as those inside radioactive laboratories or facilities, whereas EAI Supergel can
be used easily on any surface, including textured surfaces such as concrete, asphalt, or limestone.
Because use of a vacuum cleaner is necessary to remove EAI Supergel, whereas removal of
DeconGel™ can occur by hand, less overall time is required for the decontamination process by use
of DeconGel™ on medium-size surfaces (like the surfaces used in this test). However, this situation
may change if cleanup of a large contaminated area outside occurs by use of an industrial vacuum
cleaner instead of hand-held vacuum equipment.
In this research, conducted in November 2015, the same procedures were tested on vertical surfaces,
with small changes introduced that accorded with lessons learned from this work and from EPA tests
during June 2015 in Columbus, Ohio.
5.2 Test Program 2
Test Program 2 resulted in determinations of average %Rs and conclusions regarding some
operational parameters of the decontamination process. This section summarizes these results and
major conclusions drawn from them, and compares the results to those from Test Program 1
experiments on horizontal surfaces.
Major conclusions drawn from the summary of experimental results listed in Tables 3-5 and 3-6 are:
• Overall average (%R) for EAI Supergel is larger than that for DeconGel™.
• The second cleaning process improves overall cleaning efficiency.
• Average %Rs calculated from beta measurements are larger than those calculated from
gamma measurements.
• DeconGel™ is not suitable for decontamination of textured surfaces, but works well on
smooth, non-porous surfaces.
• EAI Supergel should be vacuumed no more than 30 min after spraying it on the surface.
37
-------
• Processes of preparing both gels for use are not complicated, with an advantage to
DeconGel™ that comes as a ready-to-use commercial product.
• Unskilled workers can be used to conduct decontamination after undergoing a short
training.
• Both materials are not toxic, easy to use, and easily set up.
• Use of both materials generated very low amounts of dry waste materials.
• DeconGel™ might damage irregular and porous surfaces somewhat.
In previous experiments, horizontal surfaces made of concrete and ceramic contaminated with two
radioisotopes 86Rb and 137Cs were decontaminated by use of EAI Supergel and DeconGel™. Results
of these experiments induced similar conclusions regarding time needed to clean the surfaces, better
decontamination results from use of EAI Supergel than from use of DeconGel™, inappropriateness
of DeconGel™ to clean irregular and porous surfaces, and improvement in the decontamination
factor after repeating the decontamination process. Comparing cleanups of horizontal and vertical
surfaces, no significant differences were found in calculated average %R for concrete (the only
surface used in both experiments) and in most operational parameters. The only significant
differences found were:
• Time needed to spray EAI Supergel on a vertical surface was shorter (2.5±1.8 and
4.1±1.2 min/m2 for vertical and horizontal surfaces, respectively).
• Time needed to remove DeconGel™ from the concrete vertical surface was longer
(5.0±1.4 and 2.5±0.2 min/m2 for vertical and horizontal surfaces, respectively).
Another parameter evaluated in this experiment for the first time was average %R calculated from
both beta and the gamma measurements. This type of data evaluation allows us to differentiate
between contamination on the surface, from where most of readings of beta radiation will come, and
contamination that penetrates into deeper layers of the surface, where most beta radiation will be
absorbed and from where only gamma radiation will be measured. Comprehensive measurements of
the relative fraction of beta radiation absorbed in the surface material did not occur during this field
experiment. These kind of measurements, complemented by simulations, can occur in the future in a
small-scale laboratory experiment.
As expected, for all surfaces, average %Rs calculated by use of beta readings were higher than those
calculated from gamma readings. This indicates that ability of both gels to clean upper layers of
surfaces is better than their ability to penetrate surfaces and clean up contamination that penetrates
the surfaces. Assumedly, percentage removed would be greater if the same test would be conducted
with use of an alpha emitter, because of the smaller mean free path of this "radiation" (alpha particles
[helium+2]) in matter.
These findings indicate that in a real scenario, most radioisotopes that lie on the surface will be
removed by the gel, leaving only those that penetrated the surface to a depth where they cannot
38
-------
directly contaminate the environment or threaten recontamination that might result from actions of
wind, rain, people, or passing vehicles; and these radioisotopes at depth can be addressed in later
stages of the decontamination process.
Further experiments, in which samples from surfaces contaminated with alpha and beta emitters
will be collected and measured as a function of depth, are necessary to verify this assumption.
39
-------
6.0 References
Beth-El Group. 2015. http://www.beth-el-group.com/. Last accessed on April 21, 2015.
Drake, J. 2011a. CBI Polymers DeconGel® 1101 and 1108 for Radiological Decontamination.
U.S. Environmental Protection Agency (EPA) Technology Evaluation Report.
EPA/600/R-11/084. August.
Drake, J. 2011b. Argonne National Laboratory Argonne SuperGel for Radiological
Decontamination. EPA Technology Evaluation Report. EPA/600/R-11/081. August.
Drake, J. 201 lc. Environmental Alternatives, Inc. Rad-Release I and II for Radiological
Decontamination. EPA Technology Evaluation Report. EPA/600/R-11/083. August.
Drake, J. 2013a. Decontamination of Concrete and Granite Contaminated with Cobalt-60 and
Strontium-85. EPA Technology Evaluation Report. EPA/600/R-13/002. February.
Drake, J. 2013b. Decontamination of Concrete with Aged and Recent Cesium Contamination.
EPA Technology Evaluation Report. EPA/600/R-13/001. May.
Drake, J. 2013c. Environment Canada's Universal Decontamination Formulation. EPA
Technology Evaluation Report. EPA/600/R-13/048. May.
Drake, J. 2013d. Decontamination of Concrete and Granite Contaminated with Americium-243.
EPA Technology Evaluation Report. EPA/600/R-13/204. September.
Drake, J. 2013e. Decontamination of Cesium, Cobalt, Strontium, and Americium from Porous
Surfaces. EPA Technology Evaluation Report. EPA/600/R-13/232. November.
Harper, F.T., S.V. Musolino, and W.B. Wente. 2007. "Realistic Radiological Dispersal Device
Hazard Boundaries and Ramifications for Early Consequence Management Decisions,"
Health Physics: 93.
Isorad Radiopharmaceutical Division. 2015.
http://isorad.starltd.net/products/9QMoQQmTc Generator/. Last accessed on
April 21, 2015.
Lee, S.L., D. Windover, M. Doxbeck, and T.M. Lu. 2000. Image Plate X-ray Diffraction and
X-ray Reflectivity Characterization of Protective Coatings and Thin Films. ARDE
Technical Report. ARCCB-TR-00011.
NEGEV. 2016. http://export.negev-new.co.il/index.html
Paz, O., Tal, E.J.C. Borojovich, R. Bar Ziv, R. Chakhmon, and I. Yaar. 2014. Study of Cleanup
Procedures for Contaminated Areas, Evaluation of Rubidium as a Surrogate to Cesium.
Nuclear Research Center, Negev (NRCN) Technical Report. June 30.
Rotem Industries, Ltd. (Rotem). 2015. http://rotem-medical.com
S1-278. 2005.
http://www.engsapir.co.il/images/UL240756/2378%20%D7%Q7%D7%QC%D7%A7%20
2-l.pdf
Tamar Group. 2015. http://www.tamar-group.com/. Last accessed on April 21, 2015.
40
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Tetra Tech, Inc. (Tetra Tech). 2015. "White City" Task Plan U.S.-Israel Joint Research, Test and
Evaluation Plan for Radiological Decontamination Technologies. Technical Direction
Document No. TTEMI-06-005-0013, January 13.
U.S. Environmental Protection Agency (EPA). 2011. Technical Brief, Evaluation of Nine
Chemical-Based Technologies for Removal of Radiological Contamination from Concrete
Surfaces. August.
Yaar, I., Halevy, Z. Berenstein, and A. Sharon. 2015. Protecting Transportation Infrastructure
against Radiological Threat, Simon Hakim Ed., in Protecting Critical Infrastructure,
Springer 133.
Yaar, I., 2016. Thermogravimetric analysis of test surfaces used in Test Program 2, 4. May.
ZICO. 2016. ZICO 9622. http://www.zicotech.com/index.asp'?id=2226
41
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Appendix A: Isolation Chamber Specifications
IsoArk 220-520 decontamination chambers (isolation chambers) will be used for this project.
The chambers are manufactured by Beth-El Zikhron Yaaqov Industries Ltd (Beth El Industries)
in Zikhron Yaagov, Israel. The IsoArk is a portable, negative-pressure isolation chamber
designed for patient treatment and biological, chemical, or radiological contamination sample
handling; the decontamination chamber is used in hospitals, airports, and field hospitals.
IsoArk is a complete solution for converting any room or space into a radiologically-contained
area, allowing for isolation of contaminated people or samples. The IsoArk system meets all of
today's standards for airborne-contaminated isolation, including Centers for Disease Control
and Prevention (CDC) guidelines for healthcare infection control.
The airlock, attached to the main chamber, provides the capability of easy movement in and out
of IsoArk without losing negative pressure or contaminating the outside environment.
IsoArk FA 2000 HSZ is a filtration system, equipped with a high-efficient particulate air (HEPA)
filter and a radiation source. The HEPA filter traps airborne particulates, aerosols, and viruses,
whereupon the radiation source destroys them. IsoArk FA 2000 HSZ is a self-contained mobile
unit with three airflow modes, allowing quick air flushing or energy saving at low airflow mode.
The IsoArk chambers that will be used in the test plan were preliminarily designed and
manufactured according to NRCN special demands to meet all of the demands of this unique test
plan. In particular, use of large surfaces, liquid radioisotope solutions, and several types of
decontamination gels was considered.
Some typical operational parameters of the IsoArk system, as measured during a real field
experiment, are listed in Table A-l, below. Figure A-l that follows shows a front view of the
IsoArk 220-520 Isolation Chamber and Filtration System. Figure A-2 thereafter shows a top view
of the IsoArk 220-520 Isolation Chamber and Filtration System.
Appendix
A-2
November 2016
-------
Test and Evaluation Plan for Radiological Decontamination Technologies
Table A-l: Typical Operational Parameters of the IsoArk System
Chamber Empty
Chamber Operational
Parameter
Minimum
Maximum
Maximum
Minimum
Maximum
Maximum
Level
Level
Delta
Level
Level
Delta
Temperature
23.2
24.2
1
23.2
24.2
1
Humidity
(%)
52
52
-
52
55
3
Noise dB)
57
62
57
65
7
Pressure Pa)
-10 Pa
-15 Pa
-15 Pa
-10 Pa
-15 Pa
-15 Pa
Minimal
gradient (Pa)
-10 PA
-10 Pa
Oxygen (%)
20.6 %
20.2 %
-
Carbon dioxide
(ppm)
-
320
-
339
Notes:
% Percent
dB Decibel
Pa Pascal
ppm parts per million
Source: http;//www.ilie-online.com/fileadmin/artimg/portable-collaDsible-negative-pressure-ic-unit-for-isolation-of-patients-
with-airborne-transmissible-diseases.pdf
Figure A-l: IsoArk 220-520 Isolation Chamber and Filtration System (Front View)
Air regulation
Pressure controller
/ unit
Air requtation
^ valve
Sleeve for
stationary btower
Shimshonit
layer
\ Waste "
disposal unit
Filtration unit FA
2000HSKA
Utility sleeves
Appendix
A-3
November 2016
-------
Test and Evaluation Plan for Radiological Decontamination Technologies
Figure A-2: IsoArk 220-520 Isolation Chamber and Filtration System (Top View)
Length /Urfock & Chamber
I 1
1
£
•B
Ground plan with the general dimensions of the IsoArk 220-520 Isolation Chamber
Chamber
Type
Width
Chamber
Width
Airlock
Width Chamber with
Filtration System
Length Main
Chamber
Length Chamber
with Airlock
22(1 X 521)
2200mm
1500mm
2950mm
2900mm
5190mm
Table A-2 lists specifications of the IsoArk 220-520 Isolation Chamber.
Table A-2: IsoArk 220-520 Isolation Chamber Specifications
Main Chamber
Length with
Airlock and
Open Doors
Chamber
Type
Length
Width
Height
Weis
ht
meters
(m)
inches
m
inches
m
inches
kilograms
(kg)
pounds
(lb)
m
inches
90x90
2.35
92.5
2.35
92.5
2.35
92.5
50
111
4.65
183
90 x 120
3.1
122
2.35
92.5
2.35
92.5
67
148
4.7
185
120x120
3.1
122
3.1
122
2.35
92.5
89
196
4.7
185
120x150
3.85
151.5
3.1
122
2.35
92.5
111
245
5.45
215
Airlock (integrated)
Chamber type
Length
Width
Height
Weig
ht
m
inches
m
inches
in
inches
kS
lb
all
0.85
33.5
0.85
33.5
2.2
87
included
Airlock
Main Chamber
200 (all aroundl
Length Mailt Chamber
Appendix
A-4
November 2016
-------
Test and Evaluation Plan for Radiological Decontamination Technologies
Table A-3 lists specifications of the IsoArk 220-520 Isolation Chamber and Filtration System.
Table A-3: IsoArk 220-520 Isolation Chamber and Filtration System Specifications
Filtration System
Technical Data
FA 300
HS
FA 300
HSA
FA 300
HSB
Nominal Voltage
230 VAC
115 VAC
100 VAC
Power Consumption
180 Watt
200 Watt
200 Watt
Nominal Frequency
50 Hz
60 Hz
60 Hz
Airflow Rate
300 m3/h (180 cfm)
Negative Pressure
>20 Pa
Noise Level
52 dB
Filter Efficiency (%)
99.9995%
Length
Width
Height
Weight
m
inches
m
inches
m
inches
kg
lbs
0.7
27.5
0.4
15.7
0.4
15.7
24
53
Notes:
cfm
Cubic feet per minute
dB
Decibel
Hz
Hertz
kg
Kilograms
lb
Pounds
m
Meter
m3/h
Cubic meters per hour
Pa
Pascals
VAC
Voltage, alternating current (AC) power
Appendix
A-5
November 2016
-------
Appendix B: Surface Data
Three concrete and three ceramics surfaces, 1.5 by 2 by 0.15 meters, were used in this test. The
concrete surfaces were made from construction grade concrete able to withstand pressures between
10 and 40 Mega-Pascal (MPa) (1450-5800 pounds per square inch [psi]). The concrete test surfaces
were composed of, by weight (not by volume), approximately 1 part Portland cement, 2 parts dry
sand, 3 parts dry stone, and 1/2 part water. For example, 1 cubic foot (0.028 m3) of concrete would
be made using 22 pounds (lb) cement (equivalent to 10.0 kilograms [kg]), 10 lb (4.5 kg) water, 41 lb
(19 kg) dry sand, and 70 lb (32 kg) dry stone (0.5- to 0.75-inch stone), and would weigh
approximately 143 pounds (65 kg). The sand used was brick sand (washed and filtered). Organic
materials (leaves, twigs, etc.) were removed from the sand and stone to ensure highest strength.
The ceramic surfaces were bought from a local supplier that purchased them from a foreign
manufacturer. The tiles meet the Israeli 314 tile standard (based on ISO-14411, ISO-10545 and BS-
EN-14411 International standards. The ceramic tiles were installed over a concrete sub floor, 10 cm
thick. The setting of the tiles on the concrete surface was conducted using a conventional mortar
compound. After all the tiles were set in the mortar and the mortar was dry, the gaps left between the
tiles were filled using a mix of grout according to the manufacturer's instructions.
The ceramics technical specifications are listed below:
• MODEL: DENVER 33 (http://www.azteca.es/ficheros sw/paginas/DENVER 33.pdf )
• SIZE: 33.3 cm X 33.3 cm
• BODY TYPE: BASES GRES PORCELANI
Each batch of concrete and ceramic test surfaces was allowed to cure for at least 30 days in open
environment.
The limestone and marble surfaces, 25 mm thick, were bought from a local supplier in Israel [NEGEV
2016], The limestone and marble surfaces were prepared to meet the Israeli SI-2378 standard (SI-2378
2005), based on the ASTM-E-527-1983-1997 International standards. The limestone and marble
surfaces were installed over a concrete subfloor, 10 cm thick. The setting of the surfaces on the concrete
surface was conducted using a conventional mortar compound. After all the surfaces were set in the
mortar and the mortar was dry, the gaps left between the tiles were filled using a mix of grout according
to the manufacturer's instructions. All of the limestone and marble test surfaces were allowed to cure
for at least 30 days in open environment.
Appendix
B-l
November 2016
-------
Appendix C: Experimental Timetables
Test Program 1
The experimental test plan for the radioisotopes 99mTc and 86Rb was implemented at Ramla during
January 4-21, 2015. The following (Figure C-l) is the experimental test plan for the radioisotope
137Cs, conducted atNRCN during March 1-12, 2015.
Day
Gel type
Surface type
Sunday 4 Jan
Monday 5 Jan
Tuesday 6 Jan
Wednesday 7 Jan
Thursday 8 Jan
8am
10am
11am
2pm
Exprinent Set up
Measurements
"mTc Contamination
Gel removal
DeconGel
Ceramics 12
1 pm
3pm
Measurements
Measurements
3pm
first week
Gel "hot" test
04/01/2015
8am
8am
11 am
9am
Exprinent Set up
Measurements
"mTc Contamination
Gel preparation
12pm
3pm
10am
Gel preparation
Measurements
Gel "hot" test
Argon Gel
Ceramics 13
1 pm
1130am, 1pm, 230pm
Gel "cold" test
Gel removal
2pm
3pm
Gel removal
Measurements
Day
Gel type
Surface type
Sunday 11 Jan
Monday 12 Jan
Tuesday 13 Jan
Wednesday 14 Jan
Thursday 15 Jan
0910-0920am
8am
0920am
8am
86Rb Contamination
Measurements
Gel first layer 48h
Day Free
Gel removal
DeconGel
Concrete 11, Ceramics 12
9am
Measurements
2pm
2nd week
Gel second layer
11/01/2015
1010-1020am
11am
0830am
1 pm
86Rb Contamination
Measurements
Gel preparation
Day Free
Measurements
Argon Gel
Concrete 21, Ceramics 22
0100-0600pm
1000-1030am
Measurements
Gel first layer 48h
1140-1200am
Gel removal
1 pm
Measurements
1110-1120am
1 pm
1110am
DeconGel
Ceramics 13
86Rb Contamination
Measurements
Day Free
Gel first layer 96h
1120-1130am
3pm
1130am
86Rb Contamination
Measurements
Day Free
Gel first layer 96h
1300pm
Argon Gel
Concrete 23
Gel removal
3pm
Measurements
12-1pm Lunch
12-1pm Lunch
12-1pm Lunch
12-1pm Lunch
Day
Gel type
Surface type
Sunday 18 Jan
Monday 19 Jan
Tuesday 20 Jan
Wednesday 21 Jan
Thursday 22 Jan
DeconGel
Concrete 11, Ceramics 12
0810-0830am
8am
8am
Gel removal
site cleaning
site cleaning
10am
Measurements
9am
9am
8am
8am
3rd week
Gel preparation
Measurements
site cleaning
site cleaning
18/01/2015
Argon Gel
Concrete 21, Ceramics 22
0940-1020am
Gel second layer
1110-1150am
Gel removal
0830am
8am
8am
Decongel
Gel removal
site cleaning
site cleaning
Ceramics 13
3pm
Measurements
1030am
Gel second layer
1200-1220pm
3pm
8am
8am
Argon Gel
Concrete 23
Gel removal
Measurements
site cleaning
site cleaning
12-1pm Lunch
12-1pm Lunch
Appendix
C-l
November 2016
-------
Day
Gel type
Surface type
Sunday* 1/3/15
Monday 2/3/15
T uesday 3/3/15
Wednesday 4/3/15
Thursday 5/3/15
0100pm
0900am
0900am
1230pm
DeconGel
Concrete 11, Ceramics 12
Measurements
Measurements
Measurements
Gel first layer 48h
Holiday
1230pm
137Cs Contamination
1100am
1100am
1000am
0200pm
Measurements
Measurements
Gel preparation
Measurements
0100pm
0100pm
Gel first layer 48h
Holiday
Argon Gel
Concrete 21, Ceramics 22
137Cs Contamination
0230pm
Gel removal
0300pm
Measurements
1200-0100pm Lunch
0100-0200pm Lunch
1200-0100pm Lunch
0100-0200pm Lunch
1200-0100pm Lunch
Day
Gel type
Surface type
Sunday 8/3/2015
Monday 9/3/2015
Tuesday 10/3/2015
Wednesday 11/3/2015
Thursday 12/3/2015
0900am
0200pm
0900am
0900am
Gel removal
Gel removal
site cleaning
site cleaning
Concrete 11, Ceramics 12
1000am
Free day
0300pm
Measurements
Measurements
0200pm
Gel second layer
0830am
0900am
0900am
Gel preparation
site cleaning
site cleaning
1000am
Gel second layer
Free day
Argon Gel
Concrete 21, Ceramics 22
1130am
Gel removal
0100pm
Measurements
1200-0100pm Lunch
1200-0100pm Lunch
1200-0100pm Lunch
1200-0100pm Lunch
1200-0100pm Lunch
Figure C-l. The experimental test plan for the radioisotope 137Cs, conducted at NRCN, March 1-12,2015
Appendix
C-2
November 2016
-------
Test Program 2
Figure C-2 is the experimental test plan for the first week, November 8-12, 2015.
1st week
8-12/11/15
Tent 1
Decon-Gel
Surface type
Day
Sunday S Nov* Monday 9 Nov Tuesday 10 Nov Wednesday 11 Nov Thursday 12 Mov
Concrete 11
1034am 1030am 0815am
Mttb Contamination DG first layer Gel removal
0130pm liOOOam
Measurements Measurements
0100 pm
DG second layer
Marble 12
1040am 1040am 0945am
MRb Contamination DG first layer Gei removal
0200p contamination DG first layer Gel removal
0230pm 0130pm
Measurements Measurements
0500pm
DG second layer
1st week
S-12/U/15
Tent 2
Argon ne
SuperGfc
Surface type
Day
Sunday 3 Mov Monday 9 Nov TiKsday 10 Nov Wednesday 11 Mov Thursday 12 Nov
Concrete 21
0130pm 0930am 0345pm 0930am
"Rb Contamination Measurements Gel preparation Measurements
0415pm
ASG first layer
0130pm
Gel removal
Marble 22
0140pm 1010am 0330pm 1010am
mR1> Contamination Measurements ASG first layer Measurements
0400pm
Gel removal
limestone 23
0150pm 1045am 0300pm 1100am
Kftt> Contamination Measurements ASG first layer Measurements
0330pm
Gel removal
Figure C-2. Experimental test plan for the first week, November 8-12, 2015
Appendix
C-3
November 2016
-------
Figure C-3 is the experimental test plan for the second week, November 15-19, 2015.
Day
Surface type
Sunday 15 Nov
Monday 16 Nov
Tuesday 17 Nov
Wednesday IS Nov Thursday 19 Nov
Concrete 11
0930am
Gel removal
0940am
Sam
site cleaning
Sam
site cleaning
2nd week
Measurements
15-19/11/15
0940am
Sam
Sam
Tent 1
DeconSel
Marble 12
Gel removal
1030am
Measurements
site cleaning
site cleaning
1000am
Sam
Sam
LimeStone 13
Gel removal
1120am
Measurements
site cleaning
site cleaning
Day
Surface type
Sunday 15 Nov
Monday 16 Nov
Tuesday 17 Nov Wednesday 18 Nov Thursday 19 Nov
Concrete 21
0100pm
Gel preparation
0220pm
ASG second layer
0250pm
Sam
site cleaning
Sam
site cleaning
2nd week
Gel removal
15-19/11/15
0310pm
Tent 2
Measurements
Argonne
0200pm
Sam
Sam
SuperGel
Marble 22
ASG second layer
0230pm
Gel removal
0400pm
Measurements
site cleaning
site cleaning
0145pm
Sam
Sam
ASG second layer
site cleaning
site cleaning
LimeStone 23
0215pm
Gel removal
0500pm
Measurements
Figure C-3. Experimental test plan for the second week, November 15-19,2015
Appendix
C-4
November 2016
-------
Appendix D: "mTc results
Some of the preliminary results obtained at the Ramla site during the tests using the radioisotope
99mTc (January 4-8, 2015) are presented in this appendix. All of these tests were conducted in
Isolation Chamber No. 1, using DeconGel™ and two surfaces: surface 12 (ceramic) and
13 (concrete). The 99mTc was prepared in spray bottles, identical to the ones used later for the 86Rb
and 137Cs tests. The DeconGel™ was sprayed on the surfaces by use of the electrical sprayer depicted
on Figure 2-10, and was left to dry for 48 hours before removal. Radiation from the surfaces was
measured by use of the 2" Nal(Tl) detector, shown on Figure 2-5, and the results were recorded by
use of the system depicted on Figure 2-6. Measurements recorded from surfaces 12 and 13 are
depicted on Figure D-l and Figure D-2, respectively. All results shown on these pictures were not
corrected for the isotope radioactive decay, half-life of 6.0067 hr (time was not recorded in these
preliminary tests). Therefore, %Rs shown are much higher than the real values that would have been
calculated if this correction had been made.
Appendix
E-l
November 2016
-------
cps
8.480E+05
7.690E+05
6.900E+05
6.110E+05
5.320E+05
V 0.9
4.530E+05
3. /40E+05
2.950E+05
2.160E+05
0.6 0.9
X (m)
935.0
854.0
773.0
692.0
611.0
530.0
449.0
368.0
>- 0.9-
-
0.6 0.9
X(m)
¦
%,R
99.92
99.90
99.89
99.87
99.85
99.84
99.82
99.80
Figure D-l. 99mTc contamination measurement map of (a) 99mTc preliminary contamination level, (b) 99mTc
contamination level after the 1st decontamination process and (c) calculated %R after the 1st
decontamination process, for surface 12 (Ceramics DeconGel™), measured with the 2" Nal(Tl) detector
Appendix
E-2
November 2016
-------
2.04E+05
1.83E+05
1.61E+05
1 40E+05
1.19E+05
9.71 E+04
7.58E+04
5.44E+04
3.30E+04
0.6 0.9
X (m)
cps
3.00E+04
2.63E+04
2.25E+04
1.88E+04
1.50E+04
1.13E+04
7.50E+03
3.75E+03
0.00
cps
¦
99.90
95.39
90.88
86.36
81.85
77.34
72.83
68.31
63.80
0.6 0.9
X(m)
%R
Figure D-2. "mTc contamination measurement map of (a) "mTc preliminary contamination level, (b) "mTc
contamination level after the 1st decontamination process and (c) calculated %R after the 1st
decontamination process, for surface 13 (Concrete DeconGel™), measured with the 2" Nal(Tl) detector
Appendix
E-3
November 2016
-------
Two of the pictures taken during the work conducted with the 99mTc radioisotope are shown on
Figures D-3 and D-4 below as examples of complications in working with this short half-life
radioisotope. To allow reasonable measurements of contamination remaining on the surfaces after
48 hours (about 8 half-lives of this radioisotope), an activity of 100 mCi 99mTc was used in these
tests. Therefore, all work in these chambers before removal of the DeconGel™ occurred with use of
lead aprons. As shown on the figures below, work with this shield was complicated and hard to
conduct compared to work with the much lower activity used during the 86Rb and 1,7Cs tests.
Figure D-3. Preparations for spraying of the DeconGel™
Figure D-4. Spraying the DeconGel™ on surface 12
Appendix
E-4
November 2016
-------
Appendix E
Test Program 1 Results
2.0-
1.5-
>-
1.0-
30
33
36
39
43
46
49
52
55
0.5-
0.5
1.0
X (m)
1.5
E,
cps
30
60
90
120
150
180
210
240
270
300
Um
2.0
1.5
E
>
1.0
0.5
0.5
1.0
X(m)
1.5
cps
I
30
60
90
120
150
180
210
240
270
300
¦
1
Figure E-l. 86Rb contamination measurement map of (a) background, (b) preliminary contamination level,
(c) contamination level after the first decontamination process, and (d) contamination level after the second
decontamination process, for surface 12 (Ceramics DeconGel™), measured with the Nal(Tl) 2" detector
Appendix
E-l
November 2016
-------
Figure E-2. The 86Rb calculated %R map plotted after the (a) first and (b) second decontamination process,
for surface 12 (Ceramics DeconGel™)
Appendix
E-2
November 2016
-------
Figure E-3.86Rb contamination measurements map of (a) background,(b) preliminary contamination level,
(c) contamination level after the first decontamination process, and (d) contamination level after the second
decontamination process, for surface 21 (Concrete, EAI Supergel), measured with the Nal(Tl) 2" detector
Appendix
E-3
November 2016
-------
Figure E-4. The 86Rb calculated %R map plotted after the (a) first and (b) second decontamination processes,
for surface 21 (Concrete, EAI Supergel)
Appendix
E-4
November 2016
-------
E 0.5
Figure E-5. The 137Cs contamination measurements map of (a) preliminary contamination level, (b)
contamination level after the first decontamination process, and (c) contamination level after the second
decontamination process, for surface 11 (Concrete, DeconGel™), measured with the Nal(Tl) 2" detector
Appendix
E-5
November 2016
-------
Figure E-6. The 137Cs calculated %R map plotted after the (a) first and (b) second decontamination processes,
for surface 11 (Concrete, DeconGel™)
Appendix
E-6
November 2016
-------
E 0.5
Figure E-7.137Cs contamination measurements map of (a) preliminary contamination level, (b) contamination
level after the first decontamination process and (c) contamination level after the second decontamination
process, for surface 12 (Ceramics, DeconGelTM), measured with the Nal(Tl) 2" detector
Appendix
E-7
November 2016
-------
Figure E-8. The 137Cs calculated %R map plotted after the (a) first and (b) second decontamination processes,
for surface 12 (Ceramics, DeconGel™)
Appendix
E-8
November 2016
-------
E 0.5-
Figure E-9.137Cs contamination measurements map of (a) preliminary contamination level, (b) contamination
level after the first decontamination process and (c) contamination level after the second decontamination
process, for surface 21 (Concrete, EAI Supergel), measured with the Nal(Tl) 2" detector
Appendix
E-9
November 2016
-------
Figure E-10. The 137Cs calculated %R map plotted after the (a) first and (b) second decontamination
processes, for surface 21 (Concrete, EAI Supergel)
Appendix
E-10
November 2016
-------
E 0.5
Figure E-ll. 137Cs contamination measurements map of (a) preliminary contamination level, (b)
contamination level after the first decontamination process and (c) contamination level after the second
decontamination process, for surface 22 (Ceramics, EAI Supergel), measured with the Nal(Tl) 2" detector
Appendix
E-ll
November 2016
-------
X (m)
0.0 0.5 1.0 1.5
X (m)
Figure E-12. The 137Cs calculated %R map plotted after the (a) first and (b) second decontamination
processes, for surface 21 (Ceramics, EAI Supergel)
Appendix
E-12
November 2016
-------
Appendix F
Test Program 2 Results
2806 0.5
7.887
5.994
4.100
Figure F-l. Contamination measurement results for surface 11 (concrete - DeconGel™): (a) preliminary
contamination level, (b) and (c) contamination levels after the first and second decontamination processes,
respectively, (d) and (e) calculated %R values plotted after the first and second decontamination processes,
respectively, measured with the Nal(Tl) 2" detector
Appendix
F-l
November 2016
-------
2.0
%R
2096 0.5
32.95
29.46
25.96
22.47
18.98
15.48
11.99
8.494
5.000
0.5 1.0
X (m)
Figure F-2. Contamination measurement results for surface 12 (marble - DeconGel™): (a) preliminary
contamination level, (b) and (c) contamination levels after the first and second decontamination processes,
respectively, (d) and (e) calculated %R values plotted after the first and second decontamination processes,
respectively, measured with the Nal(Tl) 2" detector
Appendix
F-2
November 2016
-------
%R
945.0
1640 0.5
52.75
48.62
44.49
40.36
36.22
32.09
27.96
23.83
19.70
0.0 0.5 1.0 1.5
X (m)
Figure F-3. Contamination measurement results for surface 13 (limestone - DeconGel™): (a) preliminary
contamination level, (b) and (c) contamination levels after the first and second decontamination processes,
respectively, (d) and (e) calculated %R values plotted after the first and second decontamination processes,
respectively, measured with the Nal(Tl) 2" detector
Appendix
F-3
November 2016
-------
49.27
45.05
40.83
28.15
Figure F-4. Contamination measurement results for surface 21 (concrete - EAI Supergel): (a) preliminary
contamination level, (b) and (c) contamination levels after the first and second decontamination processes,
respectively, (d) and (e) calculated %R values plotted after the first and second decontamination processes,
respectively, measured with the Nal(Tl) 2" detector
Appendix
F-4
November 2016
-------
>- 1.0-
>_ 1.0
>- 1.0
0.0 0.5 1.0 1.5
%R
975.0
3680 0.5
46.30
43.69
41.07
38.46
35.85
33.24
30.63
28.01
25.40
X (m)
Figure F-5. Contamination measurement results for surface 22 (marble - EAI Supergel): (a) preliminary
contamination level, (b) and (c) contamination levels after the first and second decontamination processes,
respectively, (d) and (e) calculated %R values plotted after the first and second decontamination processes,
respectively, measured with the Nal(Tl) 2" detector
Appendix
F-5
November 2016
-------
41.50
38.92
36.34
735.0
980.6
26.01
23.43
20.85
28.59
Figure F-6. Contamination measurement results for surface 23 (limestone - EAI Supergel): (a) preliminary
contamination level, (b) and (c) contamination levels after the first and second decontamination processes,
respectively, (d) and (e) calculated %R values plotted after the first and second decontamination processes,
respectively, measured with the Nal(Tl) 2" detector
Appendix
F-6
November 2016
-------
Figure F-7. Calculated %R values of surface l-l(concrete - DeconGel™), plotted for the PDS-100G/ID (left)
and the RAM-SURF (right) detectors, after the first (a), (c) and second (b), (d) decontamination processes
(the PDS-100G/ID results for this surface [figures (a) and (b)] are only partially present due to inconsistency
of some of the data points taken)
2-°l
1.5-
1.0-
>-
0.5-
0.0-
1.5-
1.0-
>-
0.5-
0.0-
0.
~ (
2-°l
1.5-
74.20 E*
1.0-
65.50 >"
56.80 Q5.
48.10
39.40 0.0-
30.70
22.00 1 5
13.30 ^
1.0-
4.600 >-
0.5-
0.0
5 0
74.80
67.45
60.10
52 75
? / ii
.0 0.5 1.0 1
X (m)
45.40
38.05
30.70
23.35
16.00
Figure F-8. Calculated %R values of surface 1-2 (marble - DeconGel™), plotted for the PDS-100G/ID (left)
and the RAM-SURF (right) detectors, after the first (a), (c) and second (b), (d) decontamination processes
Appendix
F-7
November 2016
-------
48.70
43.20
37.70
32.20
26.70
21.20
15.70
10.20
4.700
74.20
67.85
61.50
55.15
48.80
42.45
36.10
29.75
23.40
Figure F-9. Calculated %R values of surface 1-3 (limestone - DeconGel™), plotted for the PDS-100G/ID (left)
and the RAM-SURF (right) detectors, after the first (a), (c) and second (b), (d) decontamination processes
56.20
51.05
45.90
40.75
35.60
30.45
25.30
20.15
15.00
85.60
75.22
70.04
64.85
59.66
54.48
49.29
44.10
Figure F-10. Calculated %R values of surface 2-1 (concrete - EAI Supergel), plotted for the PDS-100G/ID
(left) and the RAM-SURF (right) detectors, after the first (a), (c) and second (b), (d) decontamination
processes
Appendix
F-8
November 2016
-------
2.0-,
o o
>-
>-
53.10
74.00
48.13
68.75
43.15
63.50
38.17
58.25
53.00
33.20
47.75
28.23
42.50
23.25
37.25
18.27
32.00
13.30 >-
Figure F-ll. Calculated %R values of surface 2-2 (marble - EAI Supergel), plotted for the PDS-100G/ID
(left) and the RAM-SURF (right) detectors, after the first (a), (c) and second (b), (d) decontamination
processes
>-
>-
77.50
72.39
67.28
39.18
62.16
57.05
51.94
46.83
0.0-1
0.0 0.5
Figure F-12. Calculated %R values of surface 2-3 (limestone - EAI Supergel), plotted for the PDS-100G/ID
(left) and the RAM-SURF (right) detectors, after the first (a), (c) and second (b), (d) decontamination
processes
Appendix
F-9
November 2016
-------
vvEPA
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development (8101R)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
------- |