EPA/600/R-13/232 | November 2013 | www.epa.gov/ord
United States
Environmental Protection
Agency
Technology Evaluation Report
Decontamination of Cesium,
Cobalt, Strontium, and Americium
from Porous Surfaces
Office of Research and Development
National Homeland Security Research Center
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EPA 600-R-13-232
November 2013
Technology Evaluation Report
Decontamination of Cesium, Cobalt, Strontium, and
Americium from Porous Surfaces
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NC 27711
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Disclaimer
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development's National Homeland Security Research Center, funded and managed this
technology evaluation through Contract No. EP-C-11-038 with Battelle. This report has been
peer and administratively reviewed and has been approved for publication as an EPA document.
The views expressed in this report are those of the authors and do not necessarily reflect the
views or policies of the Agency. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use of a specific product.
Questions concerning this document or its application should be addressed to:
John Drake
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency
26 West Martin Luther King Dr.
Cincinnati, OH 45268
513-569-7164
drake.john@epa.gov
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Acknowledgments
Contributions of the following individuals and organizations to the development of this
document are gratefully acknowledged.
United States Environmental Protection Agency (EPA)
John Drake, National Homeland Security Research Center (NHSRC)
John Hall, NHSRC
Paul Kudarauskas, Office of Emergency Management (OEM), Consequence Management
Advisory Team (CMAT)
Sandra Elkouz, Office of Radiation and Indoor Air (ORIA)/LV
Joan Bursey, QA Reviewer
Battelle Memorial Institute
United States Department of Energy's Idaho National Laboratory
in
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Contents
Disclaimer ii
Acknowledgments iii
Contents iv
Abbreviations/Acronyms vii
Executive Summary 1
1.0 Introduction 3
2.0 Technology Description 5
2.1 CBI Polymers DeconGel 1108 5
2.2 EAI Rad-Release II 5
2.3 Argonne SuperGel 6
2.4 IntekTechnologyLH-21 7
2.5 Karcher-Futuretech RDS 2000 7
2.6 Argonne Wash Aid 7
3.0 Experimental Details 8
3.1 Experimental Preparation 8
3.1.1 Surface Coupons 8
3.1.2 Coupon Contamination 10
3.1.3 Measurement of Activity on Coupon Surface 12
3.1.4 Surface Coupon Placement on Test Stands 12
3.2 Decontamination Technology Procedures 13
3.2.1 DeconGel 13
3.2.2 EAIRRII 14
3.2.3 Argonne National Laboratory ASG 14
3.2.4 IntekLH-21 15
3.2.5 Karcher-Futuretech RDS 2000 15
3.2.6 Argonne National Laboratory Wash Aid 15
3.3 Decontamination Conditions 16
4.0 Quality Assurance/Quality Control 17
4.1 Intrinsic Germanium Detector 17
4.2 Audits 18
4.2.1 Performance Evaluation Audit 18
4.2.2 Technical System Audit (TSA) 18
4.2.3 Data Quality Audit 18
4.3 QA/QC Reporting 18
5.0 Evaluation Results and Performance Summary 20
5.1 Decontamination Efficacy 20
5.1.1 DeconGel Results 20
5.1.2 RRII Results 22
iv
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5.1.3 ASGResults 23
5.1.4 LH-21 Results 24
5.1.5 RDS2000 27
5.1.6 Wash Aid Results 28
5.1.7 Cs-137 Removal from Wash Aid Effluent with Vermiculite Clay 29
5.2 Deployment and Operational Factors 29
5.2.1 DeconGel 29
5.2.2 RRII 30
5.2.3 ASG 31
5.2.4 LH-21 32
5.2.5 RDS2000 33
5.2.6 Wash Aid 34
6.0 References 35
v
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Tables
Table ES-1. Summary of decontamination efficacy in percent removal (%) 2
Table 3-1. Description of Surface Materials 8
Table 3-2. Concrete Characterization 9
Table 3-3. Technologies, Contaminants, and Coupons in Technology Evaluation 11
Table 3-4. Details of Each Testing Time Period 16
Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies 17
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check 19
Table 5-1. DeconGel Cs-137 Decontamination Efficacy Results 21
Table 5-2. DeconGel Concrete Decontamination Efficacy Results 22
Table 5-3. RRII Cs-137 Decontamination Efficacy Results 23
Table 5-4. ASG Cs-137 Decontamination Efficacy Results 24
Table 5-5. LH-21 Cs-137 Decontamination Efficacy Results 26
Table 5-6. LH-21 Am-243 from Concrete Decontamination Efficacy Results 26
Table 5-7. RDS 2000 Decontamination Efficacy from Concrete Results 27
Table 5-8. Wash Aid Decontamination Efficacy for Removal of Cs-137 from Concrete and
Asphalt Results 28
Table 5-9. Cs-137 Removal from Wash Aid (with Vermiculite Clay) Results 29
Table 5-10. Operational Factors of DeconGel 30
Table 5-11. Operational Factors of RRII 31
Table 5-12. Operational Factors of ASG 32
Table 5-13. Operational Factors of LH-21 33
Table 5-14. Operational Factors of RDS 2000 34
Figures
Figure 3-1. Surface finish of concrete, granite, limestone (top, left to right), marble (bottom left)
and asphalt (bottom, middle and right) coupons 9
Figure 3-2. Demonstration of contaminant application technique 12
Figure 3-3. Containment tent (outer view) and inner view with large and small test stands
containing contaminated coupons 13
Figure 3-4. Wet DeconGel and DeconGel removal 13
Figure 3-5. Rinsing and vacuuming RRII from concrete coupon 14
Figure 3-6. ASG before application, as applied to coupon, and during vacuum removal 15
Figure 3-7. Wash Aid test stand, Wash Aid experimental setup, and clay mixing setup 16
VI
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Abbreviations/Acronyms
Am
ANL
ANSI
ASG
Bq
°C
cm
CMAT
Co
Cs
DARPA
DF
DHS
DI
EAI
EPA
Eu
g
HSRP
IEEE
INL
keV
1
mL
m
m2
jiCi
nCi
NHSRC
NIST
OEM
ORD
%R
PPE
QA
QAPP
QC
QMP
RDD
RML
RRII
RSD
amencium
Argonne National Laboratory
American National Standards Institute
Argonne SuperGel
becquerel
degrees Celsius
centimeters
Consequence Management Advisory Team
cobalt
cesium
Defense Advanced Research Projects Agency
decontamination factor
U.S. Department of Homeland Security
deionized
Environmental Alternatives, Inc.
U.S. Environmental Protection Agency
europium
gram
Homeland Security Research Program
Institute of Electrical and Electronics Engineers
Idaho National Laboratory
kilo electron volts
liter
milliliter
meter
square meters
microCuries
nanoCuries
National Homeland Security Research Center
National Institute of Standards and Technology
Office or Emergency Management
Office of Research and Development
percent removal
personal protective equipment
quality assurance
quality assurance project plan
quality control
quality management plan
radiological dispersion device
Radiological Measurement Laboratory
Rad-Release II
relative standard deviation
vn
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Sr strontium
Th thorium
ISA technical systems audit
TTEP Technology Testing and Evaluation Program
Vlll
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Executive Summary
The U.S. Environmental Protection Agency's (EPA's) Homeland Security Research Program
(HSRP) is helping to protect human health and the environment from adverse impacts resulting
from Chemical, Biological, Radiological and Nuclear (CBRN) contamination whether it results
from an intentional act (for instance, terrorism) a criminal act, or an unintentional act (such as a
natural disaster or industrial accident). One way EPA helps to protect human health and the
environment is by carrying out performance tests on homeland security technologies. Through
its Technology Testing and Evaluation Program (TTEP), EPA recently evaluated the
performance of several commercially available radiological decontamination technologies as
they might be applied to a variety of contaminated building materials for decontamination of
several radionuclides which might potentially be used in a nuclear device or radiological
dispersal device. The results of this evaluation are intended to provide high-quality information
useful to decision makers in purchasing or applying the evaluated technologies. TTEP provides
potential users with unbiased third-party information that can supplement vendor-provided
information.
The materials chosen are representative of those commonly used in urban infrastructure
(Portland Type II concrete, asphalt) as well as for infrastructure of high cultural or historical
significance (Indiana limestone, Milford Pink split face granite, Colorado Yule marble). The
radionuclides chosen for this evaluation included radioactive cesium (Cs)-137, cobalt (Co)-60,
strontium (Sr)-85 and americium (Am)-243. The technologies evaluated were selected based on
the results of previous EPA technology evaluations, and included CBI Polymers' DeconGel
1108, Environmental Alternatives, Inc.'s Rad-Release II (RRII), Argonne National Laboratory's
SuperGel (ASG), Intek Technologies' LH-21, and Karcher Futuretech's RDS 2000. Also
evaluated were Argonne National Laboratory's Wash Aid (intended specifically for removal of
radiological cesium contamination) and vermiculite clay, for its ability to remove Cs-137 from
the Wash Aid effluent.
Prior to the application of each decontamination technology, 15 centimeter (cm) x 15 cm
coupons of limestone, split face granite, marble, unpainted concrete, and asphalt were
contaminated with liquid aerosols of Cs-137, Co-60, Sr-85 and/or Am-243 (not all surfaces were
contaminated with all contaminants during this evaluation) and placed on test stands inside a
radiological enclosure. Following manufacturer's recommendations, the decontamination
technologies were applied to the coupons on the test stands. Thereafter, the residual activity on
the contaminated coupons was measured and decontamination efficacy, in terms of percent
removal (%R) was calculated. Important deployment and operational factors were also
documented and reported.
A summary of results from this evaluation is presented in Table ES-1 with a detailed discussion
of these results in Section 5.0, including a discussion of various factors related to operational
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deployment. Not all combinations of technology/radionuclide/material were attempted in this
evaluation and priority was given to combinations which included Cs-137 and concrete, the
contaminant and material of widest concern. As noted in Table ES-1, some data are available
from previous EPA evaluations.
Table ES-1. Summary of decontamination efficacy in percent removal (%)
Technology
DeconGel
RRII
ASG
LH-21
RDS 2000
Wash Aid
Vermiculite Clay
Effluent
Treatment
Material
Concrete
Limestone
Marble
Granite
Concrete
Limestone
Marble
Granite
Concrete
Limestone
Marble
Granite
Concrete
Limestone
Marble
Granite
Concrete
Concrete
Asphalt
Cs-137
(a)
35
93
72
(a)
38
89
72
(a)
15
71
50
45
39
91
56
11
24
36
Co-60
85
(b)
(b)
(b)
(b)
52
Sr-85
64
(b)
(b)
(b)
(b)
43
Am-243
(d)
(c)
(c)
(c)
(c)
83
69
Wash Aid was designed specifically to remove
only Cs-137 from porous materials
Vermiculite clay process is intended only as a
means of removing Cs-137 from the Wash Aid
effluent
(a) U.S. EPA. Evaluation of Nine Chemical-Based Technologies for Removal of Radiological Contamination from Concrete
Surfaces. U.S. Environmental Protection Agency, Washington, DC, EPA/600/S-11/009, 2011
(b) U.S. EPA. Decontamination of Concrete and Granite Contaminated with Cobalt-60 and Strontium-85. U.S. Environmental
Protection Agency, Washington, DC, EPA/600/R-13/002, 2012
(c) U.S. EPA. Decontamination of Concrete and Granite Contaminated with Americium-243. U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-13/204, 2013
(d) U.S. EPA. CBI Polymers DeconGel®) 1108 for Radiological Decontamination of Americium. U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-12/067, 2012
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1.0 Introduction
The U.S. Environmental Protection Agency's (EPA's) Homeland Security Research Program
(HSRP) is helping to protect human health and the environment from adverse effects resulting
from intentional acts of terror. With an emphasis on decontamination and consequence
management, water infrastructure protection, and threat and consequence assessment, HSRP is
working to develop tools and information that will help detect the intentional introduction of
chemical or biological contaminants in buildings or water systems, the containment of these
contaminants, the decontamination of buildings and/or water systems, and the disposal of
material resulting from cleanups.
EPA, through its Technology Testing and Evaluation Program (TTEP), works in partnership with
recognized testing organizations; with stakeholder groups consisting of buyers, vendor
organizations, and permitters; and with the participation of individual technology developers in
carrying out performance tests on homeland security technologies. The program evaluates the
performance of innovative homeland security technologies by developing evaluation plans that
are responsive to the needs of stakeholders, conducting tests, collecting and analyzing data, and
preparing peer-reviewed reports. All evaluations are conducted in accordance with rigorous
quality assurance (QA) protocols to ensure that data of known and high quality are generated and
that results are defensible. TTEP provides high-quality information that is useful to decision
makers in purchasing or applying the evaluated technologies. TTEP provides potential users
with unbiased third-party information that can supplement vendor-provided information.
Stakeholder involvement ensures that user needs and perspectives are incorporated into the
evaluation design so that useful performance information is produced for each of the evaluated
technologies.
Through TTEP, EPA recently evaluated the performance of several commercially available
radiological decontamination technologies as they might be applied to a variety of contaminated
building materials for decontamination of several radionuclides which might potentially be used
in a nuclear device or radiological dispersal device. The materials chosen are representative of
those commonly used in urban infrastructure (Portland Type II concrete, asphalt) as well as for
infrastructure of high cultural or historical significance (Indiana limestone, Milford Pink split
face granite, Colorado Yule marble). The technologies evaluated were selected based on the
results of previous EPA technology evaluations, and included CBI Polymers' DeconGel 1108,
Environmental Alternatives, Inc.'s Rad-Release II (RRII), Argonne National Laboratory's
SuperGel (ASG), Intek Technologies' LH-21, and Karcher Futuretech's RDS 2000. Also
evaluated were Argonne National Laboratory's Wash Aid (intended specifically for removal of
radiological cesium contamination) and vermiculite clay, for its ability to remove Cs-137 from
the Wash Aid effluent. The radionuclides chosen for this evaluation included radioactive cesium
(Cs)-137, cobalt (Co)-60, strontium (Sr)-85 and americium (Am)-243. Sr-85 and Am-243 were
used because of the measurement difficulties of Sr-90 and Am-241 (more readily available
isotopes). Sr-90 cannot be quantified with gamma counting as it is only a beta emitter and Am-
241 is primarily an alpha emitter. Because of the nature of chemical isotopes, there is no reason
to believe that the alternative isotopes will behave any differently than the other isotopes. This
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evaluation was conducted according to a quality assurance project plan (QAPP) entitled,
"Evaluation of Chemical Technologies for Decontamination of Cesium, Cobalt, Strontium, and
Americium from Porous Surfaces", Version 1.0 dated February 15, 2013 which was developed
according to the requirements of the TTEP Quality Management Plan (QMP) Version 3, January
2008. Not all combinations of technology/radionuclide/material were attempted in this
evaluation and priority was given to combinations which included Cs-137 and concrete, the
contaminant and material of widest concern. The following performance characteristics of
DeconGel, RRII, ASG, LH-21, RDS 2000 and Wash Aid were evaluated:
• Decontamination efficacy defined as the extent of radionuclide removal following
application of the six decontamination technologies to marble, granite, limestone, asphalt
or concrete coupons to which Cs-137, Co-60, Sr-85 or Am-243 had been applied.
Another quantitative parameter evaluated was the extent of cross contamination onto
uncontaminated surfaces due to the decontamination procedure.
• Deployment and operational data including rate of surface area decontamination,
applicability to irregular surfaces, skilled labor requirement, utilities requirements, extent
of portability, shelf life of media, secondary waste management including the estimated
amount and characteristics of the spent media, and the cost of using the technologies.
This technology evaluation took place from March through June 2013 at the U.S. Department of
Energy's Idaho National Laboratory (INL).
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2.0 Technology Description
This report provides results for the evaluation of DeconGel, RRII, ASG, LH-21, RDS 2000 and
Wash Aid. Following is a description of each technology based on information provided by the
vendors. The information provided below was not verified during this evaluation.
2.1 CBI Polymers DeconGel 1108
DeconGel 1108 (CBI Polymers, Honolulu, HI, USA) is a strippable coating designed for safely
removing radioactive contamination or as a covering to contain contamination. DeconGel is sold
as a paint-like formulation. Application options include use of a paint brush, roller, or sprayer.
The water-based wet coating (hydrogel) can be applied to horizontal, vertical or inverted surfaces
and can be applied to most surfaces including bare, coated and painted concrete, aluminum, steel,
lead, rubber, plexiglas®, herculite®, wood, porcelain, tile grout, and vinyl, ceramic and linoleum
floor tiles. Following application, the coating requires approximately 12 hours to cure prior to
removal. When dry, the product binds the contaminants into a polymer matrix. The dried
coating containing the encapsulated contamination can then be peeled off the surface and
disposed of. More information is available at www.decongel.com [accessed 9/13/13].
2.2 EAI Rad-Release II
The RRII (Environmental Alternatives, Inc., Keene, NH, USA) decontamination technology is a
chemical process that involves the sequential topical application of two solutions (applied in the
order directed by EAI). RRII extracts radionuclides, including transuranics, from nearly all
substrates. This process was developed to be used in sequence to synergistically remove the
contaminants via the migration pathways, pores and capillaries of the contaminated material.
To maximize the efficacy of the extraction process, the chemistry and application are tailored to
the specific substrate, targeted contaminant(s), and surface interferences. RRII Formula 1
contains salts to promote ion exchange and surfactants to remove dirt, oil, grease, and other
surface interferences. Broad-target and target-specific chelating agents are blended into the
solution to sequester and encapsulate the contaminants, keeping them in suspension until they are
removed by the subsequent rinse. RRII Formula 2 is designed as a caustic solution containing
salts to promote ion exchange, ionic and nonionic surfactants, and additional sequestering agents,
also utilized to encapsulate the contaminants and keep them in suspension until they are removed
by the subsequent rinse.
RRII is applied in low volumes, as either an atomized spray or foam (active ingredients do not
change). According to the manufacturer, foam deployment of the solution is most appropriate
for large-scale applications, while the spray application (as used during this evaluation) is
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beneficial for smaller applications and applications where waste minimization is a critical factor.
Several options are available to facilitate the removal step including vacuuming, simple wiping
with absorbent laboratory wipes or rags for small surfaces, use of a clay overlay technique to
wick out RRII and contamination over time and then removing the clay at a later date, or use of
an absorbent polymer that is sprayed over the chemically treated surface to leach or wick out the
contaminant laden solutions and bind them. The sequence of application, dwell, rinse, and
removal of the decontamination solution constitutes a single iteration. This procedure may be
repeated, as needed, until the desired residual contaminant levels are achieved. More
information is available at www.eai-inc.com [accessed 9/13/13].
2.3 Argonne SuperGel
ASG (Argonne National Laboratory, Lemont, IL, USA) is a system of super-absorbing polymers
containing solid sequestering agents dissolved in a nonhazardous ionic wash solution. The
resulting hydrogel is applied to a contaminated surface and provides exchangeable ions to the
substrate to promote the desorption of radionuclides. The solid sequestering agent provides
strong sorption of the target radionuclides within the gel. After removing the radionuclide-laden
hydrogel by conventional wet vacuum, the contaminated hydrogel can be dehydrated or
incinerated to minimize waste volume without loss of volatilized contaminants. To summarize,
ASG provides for:
• In situ dissolution of bound contaminants without dissolving or corroding contaminated
structural components.
• Controlled extraction of water and dissolved radionuclides from the surface and
pore/microcrack structures into a super-absorbing hydrogel.
• Rapid stabilization of the solubilized radionuclides with high-affinity and high-specificity
sequestering agents immobilized in the hydrogel layer.
• Low toxicity reagents and low volume radioactive waste.
The super absorbing polymers consist of an anionic mixture of polyacrylamide and polyacrylate
in both linear and cross-linked form. The solid sequestering agents are mixed into the dry
polymer (10% by mass). The ionic wash solution is composed of a single component salt at 1
mole/liter (L) concentration (no strong acid or base is used). The reconstituted hydrogel (19 to
20 grams [g] of ionic wash solution per gram of dry polymer mix) can be applied by hand for
small areas or sprayed on for larger applications. The hydrogel is allowed to react with the
contaminated surface for at least 60 to 90 minutes to maximize the ionic exchange of
radionuclides and diffusion/absorption into the hydrogel. The hydrogel is designed to adhere to
vertical surfaces without slipping and maintain hydration in direct sunlight for more than an
hour. Because no component of the hydrogel is hazardous, no special precautions are required to
deal with hazardous materials.
Conventional wet-vacuum technology is sufficient to remove the hydrogel from the
contaminated surface. For small-scale applications, the head of a standard wet vacuum is
adequate, while for larger scale applications, a squeegee attachment is recommended.
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2.4 Intek Technology LH-21
LH-21 (Intek Technology, Fairfax, VA, USA) is a non-corrosive cleaning product developed in
2010 to remove concrete from equipment. It effectively and rapidly removes concrete, without
damaging painted surfaces, aluminum, steel, synthetic or composite materials. It also removes
lime scale and other mineral deposits. Because LH-21 is typically used as a concrete removal
agent, the efficacy of LH-21 as a surface radiological decontamination technology was unknown
prior to this testing. LH-21 is used at 1:1 dilution with fresh water and can be applied via
aerosol, low-pressure foaming system, sprayer, or brush and bucket. Light to moderate deposits
usually require one application. Heavy or aged deposits may require regular applications over a
period of hours, days or weeks. Typically, a surface is sprayed and brushed, then sprayed again
followed by an hour wait after which it is sprayed and brushed again and the decontaminant is
rinsed away. Longer wait periods may require misting with water to maintain wet. Foaming the
product via air ingestion at time of application can be a benefit, since the foam clings to surfaces
and reduces evaporative losses.
2.5 Karcher-Futuretech RDS 2000
The RDS 2000 (Karcher Futuretech GmbH, Schwaikheim, Germany) radioactive
decontamination agent consists of two separate components for the production of a radioactive
decontaminant to be used for the decontamination of surfaces contaminated with radioactive
material. RDS 2000 is made from an aqueous surfactant solution with appropriate complexing
agents, oxidants or other auxiliary substances. RDS 2000 is applied as a foam or spray. After a
waiting period for the RDS 2000 to become active, the RDS 2000 is rinsed off together with the
radioactive contaminants with water and collected in appropriate collection basins for further
disposal. With regard to environmental compatibility, RDS 2000 meets the requirements of
water pollution class 1 (low hazard for water). It is sufficiently stable during storage and ensures
an optimal coaction of conventional cleaning, decontamination effect and user-friendly handling.
2.6 Argonne Wash Aid
Wash Aid (Argonne National Laboratory, Lemont, IL, USA) is a two component system. The
first "wash" component is a brine solution that removes Cs from the surfaces of urban materials,
and the second "removal" component is vermiculite (or other specialty) clay that binds to the Cs,
allowing the Cs to be removed from the wash-water. There are different embodiments of how
this two component system could work, and for this pilot scale testing, the embodiment was to
utilize the least amount of required specialized equipment. Wash Aid is designed to be applied
as a flowing rinse decontamination agent. Wash Aid was flowed over the surface of concrete
coupons at a flow rate of 600 mL per minute for 5 minutes. The Wash Aid effluent was
collected and vermiculite clay was added to the aqueous rinse product to test the removal
efficacy of the clay when exposed to an aqueous solution of Wash Aid contaminated with Cs-
137.
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3.0 Experimental Details
3.1 Experimental Preparation
3.1.1 Surface Coupons
Coupons were fabricated of five different building materials typical of those used in urban areas
within the US. These materials included concrete, granite, limestone, marble, and asphalt. Table
3-1 describes these materials (all except concrete were purchased cut from the below sources).
Table 3-1. Description of Surface Materials
Material
Type
Concrete
Granite
Limestone
Marble
Asphalt
Name
Portland Type II
Milford Pink
Indiana Limestone
Colorado Yule
Marble
N-70 Asphalt
Source
Burns Redi-mix, Idaho
Falls, ID
Milford, MA
Oolitic, IN
Gunnison County, CO
Chicago, IL
Finish/Color
Unpolished, gray
Split face, pinkish
gray, with black and
white
Sawn, light gray
Sawn, unpolished
white with gray
markings
~20 year old street
pavement
Example Use
Urban
foundations/walls
National Archives
Building
White House
Lincoln Memorial
Weathered street
pavement
Concrete coupons were prepared in a single batch of concrete made from Type II Portland
cement. The ready-mix company (Burns Brothers Redi-Mix, Idaho Falls, ID, USA) from which
the concrete for this evaluation was obtained provided the data shown in Table 3-2 describing the
cement clinker used in the concrete mix. The ASTM C1501 requirement for Type II Portland
cement is that the tricalcium aluminate content be less than 8% of the overall cement clinker. As
shown in Table 3-2, the cement clinker used for the concrete coupons was 4.5% tricalcium
aluminate. Because the only difference between Type I and II Portland cements is the maximum
allowable tricalcium aluminate content, and the maximum for Type I is 15%, the cement used
during this evaluation meets the specifications for both Type I and II Portland cements.
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Table 3-2. Concrete Characterization
Cement Constituent
Percent of Mixture
Tricalcium Silicate
Dicalcium Silicate
Tricalcium Aluminate
Tetracalcium Aluminoferrite
Minor Constituents
57.6
21.1
4.5
8.7
8.1
The concrete coupons had a surface finish that was consistent across all the coupons. In
addition, the concrete was representative of exterior concrete commonly found in urban
environments in the United States as shown by INL under a U.S. Department of Defense,
Defense Advanced Research Projects Agency (DARPA) and U.S. Department of Homeland
Security (DHS) project .
Concrete, granite, limestone, and marble coupons to be used for this evaluation were
approximately 15 cm x 15 cm, and 4 cm thick, with a surface finish that was consistent across all
the coupons and representative of that which would be typically found on the exterior of an
urban structure.
The granite coupons were approximately 16 cm x 16 cm and 4 cm thick. These coupons
consisted of a Milford Pink Granite (Fletcher Granite Co., Westford, Massachusetts) that is
pinkish gray with areas of black and white. The surface finish of the granite coupons was that of
a split-face granite, a rugged, uneven finish produced by splitting granite with shims, wedges, or
hydraulics. This type of granite has been used in the U.S. National Archives Building, the
Smithsonian, and the U.S. Department of the Interior Building in Washington, DC. The
limestone was an Indiana Gray Limestone (Indiana Limestone, Oolitic, IN) which was uniformly
gray with a "sandy", sawn finish. The marble coupons were a Colorado Yule Marble (West Elk
Mountains, Gunnison County, CO, Colorado Stone Quaries, Inc.). The marble was white with
gray markings and a sawn, but unpolished finish. The asphalt coupons were cut out of two
Figure 3-1. Surface finish of concrete, granite, limestone (top, left to right), marble (bottom
left) and asphalt (bottom, middle and right) coupons.
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asphalt slabs (2 feet x 2 feet) from a street in downtown Chicago, IL using a standard asphalt
saw. This asphalt had been put into place approximately 20 years ago and was taken from the
street during a recent repavement. The coupons were cleaned with soap and water before
contamination. Figure 3-1 shows the surface texture of each type of surface material coupon.
3.1.2 Coupon Contamination
Table 3-1 provides the number of coupons and contaminants used with each decontamination
technology during this technology evaluation. Not all combinations of
technology/radionuclide/material were attempted in this evaluation and priority was given to
combinations which included Cs-137 and concrete, the contaminant and material of widest
concern. The technology/contaminant combinations were selected to expand on previous EPA
decontamination technology testing without duplication of previous results. Regardless of
surface type and contaminant applied, all of these coupons were contaminated with 2.5 mL of
unbuffered, slightly acidic aqueous solution containing approximately 0.4 microCurie (|iCi)/mL
Cs-137, Co-60, or Sr-85 or approximately 0.02 |iCi/mL Am-243, which corresponds to an
activity level of approximately 1 jiCi per coupon (± 0.5 jiCi) and 0.050 jiCi per coupon (±
0.5 jiCi), respectively. A lower target activity was used for Am-243 because it is also an alpha
emitter, which is a more significant internal exposure risk; thus, INL health physicists limited the
contamination levels. In the case of an actual urban radiological dispersion device (RDD) event,
dry contaminated particles are expected to settle over a wide area of a city. Application of the
radionuclides in an aqueous solution was justified because from an experimental standpoint, the
ability to apply liquids homogeneously across the surface of the coupons greatly exceeds that
capability for dry particles. The aqueous contamination was delivered to each coupon using an
aerosolization technique developed by INL under the DARPA/DHS project2. Coupons were
contaminated approximately two weeks before use.
10
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Table 3-3. Technologies, Contaminants, and Coupons in Technology Evaluation
Table 3 -3. Testing
Technology Month
ASG
RRII
March
2013
DeconGel
IntekLH-21
IntekLH-21
IntekLH-21
DeconGel
DeconGel
June
RDS2000 2013
Wash Aid (used
with alternate test
stand)
Surface
limestone
granite
marble
limestone
granite
marble
limestone
granite
marble
limestone
granite
marble
concrete
concrete
concrete
asphalt
Contaminant
cesium
cesium
cesium
cesium
americium
cesium
cobalt
strontium
cesium
cobalt
strontium
americium
cesium
Coupons
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
6
The aerosol delivery device was constructed of two syringes. The plunger and needle were
removed from the first syringe and discarded. A compressed air line was then attached to the
rear of this syringe. The second syringe containing the contaminant solution was equipped with
a 27-gauge needle, which penetrated through the plastic housing near the tip of the first syringe.
Compressed air flowing at a rate of approximately 1 to 2 L per minute created a turbulent flow
through the first syringe. When the contaminant solution in the second syringe was introduced,
the contaminant solution became nebulized by the turbulent air flow. A fine aerosol was ejected
from the tip of the first syringe, creating a controlled and uniform spray of fine liquid droplets
onto the coupon surface. The contaminant spray was applied all the way to the edges of the
coupon, which were masked with tape (after having previously been sealed with polyester resin)
to ensure that the contaminant was applied only to the working surfaces of the coupons. The
photographs in Figure 3-2 show this procedure being performed using a nonradioactive,
nonhazardous aqueous dye to demonstrate that 2.5 mL of contaminant solution is effectively
distributed across the surface of the coupon.
11
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Figure 3-2. Demonstration of contaminant application technique
3.1.3 Measurement of Activity on Coupon Surface
Gamma radiation from the surface of each contaminated coupon was measured to quantify
contamination levels both before and after application of the six decontamination technologies
using an intrinsic high purity germanium detector (Canberra LEGe Model GL 2825R/S,
Meriden, CT, USA). After each coupon was placed in front of the detector face, gamma ray
spectra were collected until the average measured activity level of Cs-137, Co-60, Sr-85 and
Am-243 from the surface stabilized to a relative standard deviation (RSD) of less than 2%.
Gamma-ray spectra acquired from contaminated coupons were analyzed using INL Radiological
Measurement Laboratory (RML) data acquisition and spectral analysis programs. Radionuclide
activities on each of the coupons were calculated based on efficiency, emission probability, and
half-life values. Decay corrections were made based on the date and the duration of the counting
period. Full RML gamma counting QA/quality control (QC), as described in the QAPP, was
employed and certified results were provided. The minimum detectable level of each
radionuclide was 0.3 nanoCuries (nCi) for Cs-137, 0.3 nCi for Co-60, 0.2 nCi for Sr-85 and
0.2 nCi for Am-243 on these coupons.
The activity measurement for the aqueous samples to show the effectiveness of vermiculite clay
removal was performed differently from the surface coupons. A 5 mL aliquot was removed and
filtered from each sample. Then a 2 mL aliquot of this filtered portion was dried slowly onto a
tare weighed metal planchet. The activity of the samples was counted in a gas-proportional gross
alpha/beta counter (WPC-1050 Automatic Low Background System, Protean Instruments
Company, Lenoir City, TN, USA) for 100 minutes. Activities are reported in units of uCi/mL.
The minimum detectable level for Cs-137 in these samples was approximately 7 x 10" |iCi/mL.
All the aqueous samples were at least 50 times that activity concentration.
3.1.4 Surface Coupon Placement on Test Stands
To evaluate the decontamination technologies (with the exception of Wash Aid) on vertical
surfaces (simulating walls) contaminated with Cs-137, Co-60, Sr-85 and Am-243, a stainless
steel test stand (2.7 m x 2.7 m) designed to hold three rows of coupons was used. The granite
coupons were slightly too big to fit into the openings in the test stand so a second smaller test
stand was used only for the granite coupons. As shown in Figure 3-3, both test stands were
located in a containment tent. The limestone, marble and concrete coupons were placed into
holders within the large test stand so their surfaces extended just beyond the surface of the
stainless steel face of the test stand and the granite coupons were placed in a row next to one
another on the smaller test stand. The middle position of the bottom row contained an
12
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uncontaminated blank concrete coupon. This blank coupon was placed there to observe the
extent of cross contamination caused by the decontamination higher on the wall or transfer of
contaminants due to use of decontamination equipment higher on the wall. Wash Aid is designed
for a high flow liquid application over surfaces so an alternative test stand was used as described
in Section 3.2.6.
Figure 3-3. Containment tent (outer view) and inner view with large and small test stands
containing contaminated coupons
3.2 Decontamination Technology Procedures
3.2.1 DeconGel
The implementation of the DeconGel technology procedure included application of two coats of
DeconGel followed by removal of the dried coating. The application was performed using a
standard 4-inch paint brush. The specifications of the paint brush were not critical as a perfectly
smooth application was not required. The paint brush was loaded with the wet coatings by
dipping the brush into a plastic bucket containing the wet coatings and then the wet coatings
were applied generously until the entire surface of the coupon was covered. The paint brush was
then used to work the wet coatings into the surfaces. The brush was then used to smooth the
applied wet DeconGel on each coupon. If areas of the coupons were not covered completely,
additional wet DeconGel was added. The first coat of the DeconGel was allowed to set for 1.5 to
2 hours and a second coat was added on top of the initial coat following the same method. The
coupons with the wet DeconGel
were allowed to dry overnight.
The dry coatings were removed
by first scoring the bottom edge of
the coupons (now covered with
dried coatings) with a plastic knife
to free corners of the dried coating
so they could be pulled off the
surface by hand. The overall
decontamination method for
DeconGel included the
Figure 3-4. Wet DeconGel and DeconGel removal
13
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application of wet coating followed by a 1.5 to 2 hour drying time and application of a second
coat that was allowed to dry overnight before removal the following day. Figure 3-4 shows a
granite coupon just after DeconGel application and the removal of dry DeconGel.
3.2.2 EAIRRII
The application of RRII was performed using plastic spray bottles (32-oz heavy duty spray
bottle, Rubbermaid Professional, Atlanta, GA). The coupons were thoroughly wetted with RRII
Formula 1 with three to four sprays. The solution was then worked into the surface of the
coupon by scrubbing the entire surface of the coupon once with a scouring pad (heavy duty
scouring pad, 3M Scotch-Brite, St. Paul, MN, USA). During this evaluation, the initial
application of RRII Formula 1 took only 15 to 20 seconds for each coupon. The next step was a
30-minute dwell time for RRII Formula 1 to reside on the surfaces of the coupons. The coupon
surfaces were kept damp with one to two sprays of additional RRII Formula 1 approximately
every 5 minutes. The additional one to two sprays of RRII Formula 1 were performed to
simulate foam collapse, i.e., the reintroduction of fresh solutions to the contaminated matrix, as
would be observed when RRII was deployed as a foam for larger scale real-world applications.
After the 30-minute dwell time, the coupon surfaces were thoroughly wetted with a 10% nitric
acid rinse solution (in deionized [DI] water)
using another spray bottle. The surface was then
vacuumed (12 gallon, 4.5 horsepower, QSP
Quiet Deluxe, Shop-Vac Corporation,
Williamsport, VA, USA) which took about 25
seconds per coupon. The above procedure was
then repeated for RRII Formula 2. Altogether,
the RRII procedure (including all the steps
above) took 79 and 72 minutes to complete for
the two sets of coupons that were decontaminated
during this technology evaluation. Figure 3-5 Figure 3-5. Rinsing and vacuuming
shows the rinse and vacuuming step of the RRII RRII from concrete coupon
procedure.
3.2.3 Argonne National Laboratory ASG
The ASG was prepared by mixing two dry powders with water as directed by Argonne staff
members via e-mailed written instructions and phone conversations. The mixture was then
stirred with a drill equipped with a mixing tool until the mixture was homogeneous. The ASG
was applied using a 4-inch paint brush to smooth the ASG across the surface. The specifications
of the paint brush were not critical as a perfectly smooth application was not required.
Altogether, the application of the ASG required approximately 20 seconds per coupon; ASG was
allowed to stay on the surface for 90 minutes, and then was removed with a wet vacuum (12
gallon, 4.5 horsepower, QSP® Quiet Deluxe, Shop-Vac Corporation, Williamsport, VA, USA)
which required approximately 20 seconds per coupon. Figure 3-6 shows the application and
vacuum removal steps for ASG.
14
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Figure 3-6. ASG before application, as applied to coupon, and during vacuum
removal
3.2.4 IntekLH-21
The application of LH-21 was performed using plastic spray bottles (32-oz heavy duty spray
bottle, Rubbermaid Professional, Atlanta, GA, USA) as directed by Intek staff members. The
LH-21 was diluted 1:1 in DI water prior to addition to the spray bottles for application to the
contaminated coupons. The coupons were thoroughly wetted with LH-21 with three to four
sprays. The solution was then worked into the surface of the coupon by scrubbing the entire
surface of the coupon once with a medium bristle brush. This initial application of LH-21 took
only 25 seconds for each coupon and was followed by a quick spray to rewet the surface of the
coupons. The next step was a 60-minute dwell time for LH-21 to reside on the surfaces of the
coupons. The coupon surfaces were kept damp with one to two sprays of additional LH-21
approximately every 10 minutes. After the 60-minute dwell time, the coupon surfaces were
thoroughly wetted with LH-21 and scrubbed just as they were initially. The coupons were then
rinsed with DI water using another spray bottle. The surface was then vacuumed which took
about 25 seconds per coupon. The total elapsed time for the entire LH-21 procedure (including
all the steps detailed above) for the nine coupons decontaminated with LH-21 was approximately
70 minutes.
3.2.5 Karcher-Futuretech RDS 2000
The application of RDS 2000 included use of a hand-pump pressurized sprayer. Futuretech
supplied two different components that had to be combined following the instructions that were
provided by Futuretech. That new solution was then diluted with DI water to make a 2%
solution by volume which was added to the hand sprayer. Each coupon was then wetted with the
RDS 2000 and scrubbed in with a medium bristle brush followed by a 5-minute dwell time.
Following the 5-minute dwell, each coupon received another application of RDS 2000 using the
hand sprayer, followed by another 5-minute dwell, and then rinsed with DI water. These
application steps were repeated once and then the rinse water was removed with a vacuum.
Application of the RDS 2000 solutions to each coupon took approximately 10 seconds. The total
elapsed time for the entire RDS 2000 procedure (including all the steps detailed above) for the
nine coupons decontaminated with RDS 2000 was approximately 17 minutes.
3.2.6 Argonne National Laboratory Wash Aid
Wash Aid was made up of a solution of 1 millimolar sodium dodecyl sulfate prepared in 0.5
Molar ammonium chloride. Wash Aid was applied to contaminated coupons individually using a
custom designed decontamination test stand that provided a way for flowing Wash Aid across
15
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the entire surface of the Cs-137 contaminated concrete and asphalt coupons at a flow rate of
600 mL/min. Each coupon was decontaminated with Wash Aid for 5 minutes and the Wash Aid
effluents from all the concrete and asphalt coupons were collected separately as composite
samples. The Wash Aid decontamination approach included a step to remove Cs-137 from the
Wash Aid effluent (post-decontamination) using the addition of vermiculite clay (Vermiculite
Ore Concentrate, VCX 205, Specialty Vermiculite Corp., Enoree, SC, USA) to the Wash Aid
effluent. Because a total of four concrete and six asphalt coupons were decontaminated, the
resulting composite concrete Wash Aid effluent totaled 12 L and the asphalt Wash Aid effluent
totaled 18 L. For each of the Wash Aid effluents, a 3 L aliquot was treated through three
successive additions of approximately 300 g of vermiculite clay (for a total of 900 g used for
each Wash Aid effluent sample). The clay was added and a kitchen mixer (MixMaster,
Sunbeam, Jarden Consumer Products, Inc., USA) was used to thoroughly mix the clay with the
Wash Aid effluent for 15 minutes. The clay was allowed to settle for 5 minutes and then the
supernatant Wash Aid effluent was poured off the clay that had settled to the bottom of the glass
mixing bowl. The clay remaining in the mixing bowl was discarded and the mixing bowl
cleaned. The supernatant Wash Aid effluent was then added back into the mixing bowl and the
clay treatment process was repeated two additional times. Wash Aid effluent samples were
collected for activity measurements before clay addition and after each successive clay
treatment. Figure 3-7 shows the Wash Aid test stand, the experimental setup (Wash Aid
container, peristaltic pump, and test stand), and the clay mixing setup.
Figure 3-7. Wash Aid test stand, Wash Aid experimental setup, and clay mixing setup
3.3 Decontamination Conditions
The decontamination technology testing was performed over the course of three days during two
different testing cycles (March and June 2013). Table 3-2 presents the temperature (or range) in
degrees Celsius (°C) and the percent relative humidity measured during the evaluation.
Table 3-4. Details of Each Testing Time Period
Temperature during Humidity during
Testing Month Decontamination (°C) Decontamination (%)
March 2013 18-21 16
June 2013 20-24 16-24
16
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4.0 Quality Assurance/Quality Control
QA/QC procedures were performed in accordance with the QMP and the QAPP for this
evaluation.
4.1 Intrinsic Germanium Detector
The germanium detector was calibrated weekly during the evaluation. The calibration was
performed in accordance with standardized procedures from the American National Standards
Institute (ANSI) and the Institute of Electrical and Electronics Engineers (IEEE).3 In brief,
detector energy was calibrated using thorium (Th)-228 daughter gamma rays at 238.6, 583.2,
860.6, 1620.7, and 2614.5 kilo electron volts (keV). Table 4-1 presents the calibration results
across the duration of the project. Each row shows the difference between the known energy
levels and those measured following calibration (rolling average across the six most recent
calibrations). Each row represents a 6-week rolling average of calibration results. These
energies were compared to the previous 30 calibrations to confirm that results were within three
standard deviations of the previous calibration results. All the calibrations fell within this
requirement.
Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies
Measurement
Month
March/April 20 13
April/May 20 13
May/June 20 13
June/July 20 13
Calibration Energy Levels (keV)
Date Range
3-18-13 to 4-30-13
4-23-13 to 5-15-13
5-15-13 to 6-17-13
6-11-13 to 7-16-13
Energy 1
238.632
-0.003
-0.005
-0.001
-0.002
Energy 2 Energy 3
583.191 860.564
0.009 -0.023
0.017 -0.056
0.001 0.016
0.004 0.006
Energy 4
1620.735
-0.184
-0.228
-0.095
-0.117
Energy 5
2614.511
0.018
0.023
0.008
0.010
Gamma ray counting was continued for each coupon until the measured activity level of Cs-137,
Co-60, Sr-85 and Am-243 on the surface had a RSD of less than 2%. This RSD was achieved
during the first hour of counting for all the coupons measured during this evaluation. The final
activity assigned to each coupon was a compilation of information obtained from all components
of the electronic assemblage that comprise the gamma counter, including the raw data and the
spectral analysis described in Section 3.1.3. Final spectra and all data that comprise the spectra
were sent to a data analyst who independently confirmed the "activity" number arrived at by the
spectroscopist. When both the spectroscopist and the data analyst independently arrived at the
same value, the data were considered certified. This process defined the full gamma counting
QA process for certified results.
17
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The background activity of laboratory blank coupons was determined by analyzing five
arbitrarily selected coupons from the stock of coupons used for this evaluation. The ambient
activity level of these coupons was measured for one hour. No activity was detected above the
minimum detectable level of 0.3 nCi for Cs-137, 0.3 nCi for Co-60, 0.2 nCi for Sr-85 and 0.2
nCi for Am-243 on these coupons.
Throughout the evaluation, a second measurement was taken on 15 coupons to provide duplicate
measurements to evaluate the repeatability of the instrument. Eight of the duplicate
measurements were performed after contamination but prior to application of the
decontamination technologies and seven were performed after decontamination. All but two of
the duplicate pairs showed a percent difference in activity level of 8% or less, and all were below
the acceptable percent difference of 10%.
Seven transport control samples (one from each contaminant/surface combination) were
analyzed during the evaluation. These samples were contaminated, measured for the pre-
decontamination activity, transported to the testing facility, and then shipped back to the RML
for a follow-up measurement of activity. The activity measured before and after shipment was
measured to determine the consistency of the gamma detector. All seven samples had percent
differences of less than 8%, well below the acceptable percent difference of 25%.
4.2 Audits
4.2.1 Performance Evaluation Audit
RML performs monthly checks of the accuracy of the Th-228 daughter calibration standards by
measuring the activity of a National Institute of Standards and Technology (NIST)-traceable
europium (Eu)-152 standard (in units of Becquerel, Bq) and comparing the results to the
accepted NIST value. Results within 7% of the NIST value are considered to be within
acceptable limits. The Eu-152 activity comparison is a routine QC activity performed by INL,
but for the purposes of this evaluation served as the performance evaluation (PE) audit, an audit
that confirms the accuracy of the calibration standards used for the instrumentation critical to the
results of an evaluation. Table 4-2 provides the results of each of these audits of the detector that
was used during this evaluation. All results were within the acceptable difference of 7%.
4.2.2 Technical System Audit (TSA)
A TSA was performed during the June 2013 testing to confirm compliance with the QAPP. No
findings were observed during the TSA.
4.2.3 Data Quality Audit
At least 10% of the data acquired during the evaluation were audited. The data was traced from
the initial acquisition, through reduction and statistical analysis, to final reporting, to ensure the
integrity of the reported results. All calculations performed on the audited data were checked for
accuracy. No significant findings were noted.
4.3 QA/QC Reporting
18
-------
Each assessment and audit was documented in accordance with the QAPP and the QMP.
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check
Date
A/Tcir^Vi 9D1 7
iviar cn zu i j
A t->t-;i om ^
April zuij
A/TOT? orn ^
iviay zu i j
Tut-iQ om i
June zuij
TnK? 9D1 7
juiy zui j
Eu-152
(keV)
Average
122
779
1408
Average
122
779
1408
Average
122
779
1408
Average
122
779
1408
Average
122
779
1408
NIST Activity
(Bq)
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
124,600
INLRML
Result (Bq)
120,500
118,100
118,500
122,500
120,200
118,000
117,600
119,000
121,000
118,500
118,800
121,000
121,400
117,900
119,500
123,400
122,300
119,500
120,800
123,000
Difference
3.3%
5.2%
4.9%
1.7%
3.5%
5.3%
5.6%
4.5%
2.9%
4.9%
4.7%
2.9%
2.6%
5.4%
4.1%
1.0%
1.8%
4.1%
3.0%
1.3%
19
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5.0 Evaluation Results and Performance Summary
5.1 Decontamination Efficacy
The decontamination efficacy was determined for each contaminated coupon in terms of percent
removal (%R) and decontamination factor (DF) as defined by the following equations:
= (l-Af/A0)x 100%
and
DF =
where A0 is the radiological activity from the surface of the coupon before application of the
decontamination technologies and Af is the radiological activity from the surface of the coupon
after decontamination. While the DFs are reported in the following data tables, the narrative
describing the results will focus on the %R.
While given in each of the tables below, the overall (DeconGel, RRII, ASG and LH-21 included)
average pre-decontamination activity (plus or minus one standard deviation) of the Cs-137
contaminated coupons was 1 . 1 1 ± 0.04 jiCi for marble (4% RSD); 1.17 ± 0.07 jiCi for granite
(6% RSD; and 0.99 ± 0.03 |iCi for limestone (3% RSD). For Cs-137, Sr-85, and Co-60 on
concrete the average activities were 0.96 ± 0.05 |iCi (5% RSD), 1.56 ± 0.09 |iCi (6% RSD), and
0.57 ± 0.03 jiCi (5% RSD), respectively. For Am-243 on concrete, the average activity was
0.050 ± 0.003 |iCi (5% RSD).
5. 1. 1 DeconGel Results
Table 5-1 presents the decontamination efficacy, expressed as both %R and DF, for DeconGel
when decontaminating Cs-137 from limestone, granite, and marble surface coupons. Table 5-2
presents the same data for Co-60 and Sr-85 decontamination from concrete. The
decontamination efficacies of DeconGel in terms of %R for Cs-137 were 35 ± 13% for the
limestone surfaces, 72 ± 4% for the granite surfaces and 93 ± 1% for the marble surfaces. These
results are comparable to the Cs-137 removal from concrete of 67 ± 9% derived from previous
EPA evaluations of DeconGel4. Co-60 removal from concrete surfaces was 85 ± 2% and for Sr-
85 was 64 ± 6%. Several t-tests were performed to determine the likelihood that the %R results
for each surface were the same. The t-test results indicated that the %R from each of the three
surfaces contaminated with Cs-137 were significantly different from one another at least at the
95% confidence level (p-values < 0.002). Similarly, the %Rs for concrete contaminated with
Co-60 and Sr-85 were also determined to be significantly different from one another (p < 0.001).
As indicated by the %Rs above, Cs-137 was most effectively removed from marble followed by
20
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granite and then limestone. Also, Co-60 was removed more effectively from concrete than was
Sr-85.
Table 5-1. DeconGel Cs-137 Decontamination Efficacy Results
Pre-
Decontamination
Activity
Surface Material (uOCoupon)
1.02
1.01
T. ^ 1.00
Limestone
Avg 1.01
SD 0.01
1.30
1.19
„ v 1.16
Gramte ^
Avg 1-18
SD 0.10
1.19
1.08
™ u, L12
Marble iw
Avg 1.12
SD 0.05
Post-
Decontamination
Activity
(uOCoupon)
0.67
0.78
0.47
0.71
0.66
0.13
0.40
0.37
0.32
0.24
0.33
0.07
0.074
0.088
0.073
0.073
0.08
0.01
%R
34%
23%
53%
30%
35%
13%
69%
69%
72%
77%
72%
3.9%
94%
92%
94%
93%
93%
0.9%
DF
1.5
1.3
2.1
1.4
1.6
0.4
3.3
3.2
3.6
4.4
3.6
0.6
16.1
12.3
15.3
15.1
14.7
1.7
21
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Table 5-2. DeconGel Concrete Decontamination Efficacy Results
Surface
Contaminant
Co-60
Avg
SD
Sr-85
Avg
SD
Pre-
Decontamination
Activity
(uCi/Coupon)
0.54
0.53
0.56
0.58
0.55
0.02
1.53
1.60
1.56
1.55
1.56
0.03
Post-
Decontamination
Activity
(uOCoupon)
0.092
0.081
0.085
0.075
0.08
0.01
0.47
0.52
0.57
0.69
0.56
0.09
%R
83%
85%
85%
87%
85%
1.7%
69%
68%
63%
55%
64%
6.1%
DF
5.9
6.5
6.6
7.7
6.7
0.8
3.3
3.1
2.7
2.2
2.8
0.4
As described above in Section 3.1.4, a cross-contamination blank was included in the test stand
during testing with each contaminant to evaluate the potential for cross contamination due to
application of DeconGel on wall locations above the blank. Each cross contamination blank was
an uncontaminated concrete coupon that had pre-decontamination activity measurements
indicating extremely low background levels (below the detection limit) of activity. These
coupons were decontaminated using DeconGel along with the other contaminated coupons and
the post-decontamination measurement of activity of the cross-contamination blank was found to
be 0.0053 jiCi for Cs-137 and not detectable for the cross-contamination blank corresponding to
the coupons contaminated with Co-60 and Sr-85. In the case of the Cs-137 cross-contamination
blank, this increased level of activity was less than 1% for Cs-137 of the activity applied to each
of the contaminated coupons. Therefore, the cross contamination was minimal but still
detectable, and enough to note that cross contamination to locations previously not contaminated
is a possibility when using DeconGel in a wide area application.
5.1.2 RRII Results
Table 5-3 presents the decontamination efficacy, expressed as both %R and DF, for RRII when
decontaminating Cs-137 from limestone, granite, and marble surface coupons. The
decontamination efficacies of RRII in terms of %R for Cs-137 were 38 ± 13% for the limestone
surfaces, 72 ± 2.5% for the granite surfaces, and 89 ± 5% for the marble surfaces. These results
are comparable to the Cs-137 removal from concrete of 85 + 2% derived from previous EPA
evaluations of RRII5. Several t-tests were performed to determine the likelihood that the %R
results for each surface were the same. The t-test results indicated that the %R from each of the
three surfaces contaminated with Cs-137 were significantly different from one another at least at
the 95% confidence level (p-values < 0.002). As indicated by the %Rs above, Cs-137 was most
effectively removed from marble followed by granite and then limestone.
22
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As described above in Section 3.1.4, cross-contamination blanks were included in the test stand
during testing to evaluate the potential for cross contamination due to application of RRII on
wall locations above the blank. Each cross contamination blank was an uncontaminated concrete
coupon that had pre-decontamination activity measurements indicating extremely low
background levels (below the detection limit) of activity. This coupon was decontaminated
using RRII along with the other contaminated coupons and the post-decontamination
measurement of activity of these blanks was found to be 0.056 jiCi for Cs-137. This increased
level of activity was less than 6% of the activity applied to each of the contaminated coupons.
Therefore, the cross contamination was minimal but still detectable, and enough to note that the
possibility exists that cross contamination to locations previously not contaminated is a
possibility when using RRII in a wide area application.
Table 5-3. RRII Cs-137 Decontamination Efficacy Results
Surface Material
Pre-
Decontamination
Activity
(^iCi/Coupon)
Post-
Decontamination
Activity
(^iCi/Coupon)
%R
DF
(
Limestone (
Avg (
SD (
Granite
Avg
SD (
Marble
Avg
SD (
[.00
).98
).99
).99
).99
).01
.26
.20
.11
.14
.18
).07
.12
.07
.14
.12
.11
).03
0.55
0.73
0.48
0.71
0.62
0.12
0.36
0.30
0.29
0.35
0.33
0.04
0.073
0.081
0.163
0.175
0.12
0.05
45%
26%
52%
28%
38%
13%
71%
75%
74%
69%
72%
3%
94%
92%
86%
84%
89%
5%
1.8
1.3
2.1
1.4
1.7
0.3
3.5
4.0
3.8
3.3
3.6
0.3
15
13
7.0
6.4
11
5
5.1.3 ASG Results
Table 5-4 presents the decontamination efficacy, expressed as both %R and DF, for ASG when
decontaminating Cs-137 from limestone, granite, and marble surface coupons. Similar data exist
for decontamination of concrete contaminated with Cs-137 using ASG6. The decontamination
efficacies of ASG in terms of %R for Cs-137 were 15± 6% for the limestone surfaces, 50 ± 3%
for the granite surfaces, and 71 ± 4% for the marble surfaces. These results are comparable to the
Cs-137 removal from concrete of 71 + 4% derived from previous EPA evaluations of ASG6.
Several t-tests were performed to determine the likelihood that results for each contaminant and
23
-------
surface were the same. Several t-tests were performed to determine the likelihood that the %R
results for each surface were the same. The t-test results indicated that the %Rs from each of the
three surfaces contaminated with Cs-137 were significantly different from one another at least at
the 95% confidence level (p-values < 0.0005). As indicated by the %Rs above, Cs-137 was most
effectively removed from marble followed by granite and then limestone.
Table 5-4. ASG Cs-137 Decontamination Efficacy Results
Surface Material
Pre-
Decontamination
Activity
(^iCi/Coupon)
Post-
Decontamination
Activity
(^iCi/Coupon)
%R
DF
Limestone
Avg
SD
Granite
Avg
SD
Marble(a)
Avg
SD
1.02
0.98
0.98
1.02
1.00
0.02
1.09
1.22
1.21
1.22
1.19
0.06
1.20
1.12
1.13
1.15
0.04
0.86
0.89
0.85
0.78
0.84
0.05
0.59
0.62
0.60
0.56
0.59
0.03
0.32
0.37
0.31
0.33
0.03
16%
9%
13%
24%
16%
6.3%
46%
49%
50%
54%
50%
3%
73%
67%
73%
71%
4%
1.2
1.1
1.2
1.3
2.0
0.1
1.8
2.0
2.0
2.2
2.0
0.1
3.8
3.0
3.6
3.5
0.4
(a) Data from one marble coupon were not used because wrong side of coupon was decontaminated.
As for the above testing, the cross-contamination blanks were included in the test stand during
testing to evaluate the potential for cross contamination due to application of ASG on wall
locations above the blank. Each cross contamination blank was an uncontaminated concrete
coupon that had pre-decontamination activity measurements indicating extremely low
background levels (below the detection limit) of activity. These coupons were decontaminated
using ASG along with the other contaminated coupons. The post-decontamination measurement
of activity of these blanks was found to be less than 0.002 jiCi for Cs-137. This increased level
of activity was approximately 0.2% of the activity added to each of the contaminated coupons for
Cs-137. Therefore the cross contamination was very minimal during application of ASG.
5.1.4 LH-21 Results
Table 5-5 presents the decontamination efficacy, expressed as both %R and DF, for LH-21 when
decontaminating Cs-137 from limestone, granite, marble, and concrete surface coupons and
Table 5-6 presents the same data for Am-243 decontamination from concrete. The
decontamination efficacies of Intek LH-21 in terms of %R for Cs-137 were 39± 10% for the
24
-------
limestone surfaces, 56 ± 5% for the granite surfaces, and 90 ± 5% for the marble surfaces. For
concrete surfaces, the %Rs were 45 ± 16% for Cs-137 and 87 ± 7% for Am-243. Several t-tests
were performed to determine the likelihood that the %R results for each surface were the same.
The t-test results indicated that the %Rs from limestone, granite, and marble are each
significantly different from one another (p-values < 0.03). The %Rs for Cs-137 from granite and
limestone were not significantly different from the %Rs from concrete (p-values > 0.2) when
compared individually with concrete. As indicated by the %Rs above, Cs-137 was most
effectively removed from marble followed by granite, concrete, and limestone. Also, Am-243
was more effectively removed from concrete than was Cs-137.
As for the above testing, the cross-contamination blanks were included in the test stand during
testing with both contaminants to evaluate the potential for cross contamination due to
application of LH-21 on wall locations above the blank. Each cross contamination blank was an
uncontaminated concrete coupon that had pre-decontamination activity measurements indicating
extremely low background levels (below the detection limit) of activity. These coupons were
decontaminated using LH-21 along with the other contaminated coupons. The post-
decontamination measurement of activity of these blanks was found to be 0.017 jiCi for Cs-137.
This increased level of activity was approximately 2% of the activity added to each of the
contaminated coupons for Cs-137. Therefore, the cross contamination was minimal but still
detectable, and enough to note that cross contamination to locations previously not contaminated
is a possibility when using LH-21 in a wide area application.
25
-------
Table 5-5. LH-21 Cs-137 Decontamination Efficacy Results
Pre-
Decontamination
Activity
Surface Material (uCi/Coupon)
0.92
1.02
T • . °-94
Limestone , ^
Avg 0.98
SD 0.05
1.11
1.18
Granite , '„ .,
1.06
Avg 1.13
SD 0.06
1.11
1.01
™ u, L08
Marble , 10
Avg 1.08
SD 0.05
0.86
1.01
„ . 0-99
Concrete „ „-.
Avg 0.95
SD 0.07
Post-
Decontamination
Activity
(uCi/Coupon)
0.58
0.58
0.46
0.75
0.59
0.12
0.51
0.53
0.43
0.52
0.50
0.05
0.12
0.02
0.08
0.18
0.11
0.06
0.63
0.39
0.43
0.59
0.51
0.12
Table 5-6. LH-21 Am-243 from Concrete Decontamination Efficacy
Pre-
Decontamination
Contaminant and Activity
Surface (uCi/Coupon)
0.052
0.054
Am-243 on 0.053
Concrete 0.048
Avg 0.052
SD 0.003
Post-
Decontamination
Activity
(uCi/Coupon)
0.0077
0.0116
0.0045
0.0032
0.007
0.004
%R
37%
43%
51%
26%
39%
10%
54%
55%
63%
51%
56%
5%
89%
98%
92%
83%
90%
5%
27%
61%
57%
37%
45%
16%
Results
%R
85%
79%
92%
93%
87%
7%
DF
1.6
1.8
2.0
1.4
1.7
0.3
2.2
2.2
2.7
2.0
2.3
0.3
9.2
40
13
5.9
12
5.0
1.4
2.6
2.2
1.6
2.0
0.6
DF
6.8
4.7
11.8
15.0
9.5
4.7
26
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5.1.5 RDS2000
Table 5-7 presents the decontaminating on efficacy, expressed as both %R and DF, for RDS
2000 when decontaminating Cs-137, Co-60, Sr- 85 and Am-243 from concrete surface coupons.
The %R values were 11 ± 4.3% for Cs-137, 52 ± 3.1% for Co-60, 43 ± 11% for Sr-85, and 69 ±
10% for Am-243. Several t-tests were performed to determine the likelihood that the %R results
between the contaminants on concrete were all the same. The t-test results indicated that the %R
of Sr-85 and Co-60 were not significantly different from one another. As indicated by the %Rs
above, Am-243 was most effectively removed from concrete followed by Co-60 and Sr-85, and
then Cs-137.
Table 5-7. RDS 2000 Decontamination Efficacy from Concrete Results
Surface
Contaminant
Cs-137
Co-60
Sr-85
Am-243
Avg
SD
Avg
SD
Avg
SD
Avg
SD
Pre-
Decontamination
Activity
(uOCoupon)
1.02
0.96
0.97
1.00
0.99
0.03
0.56
0.61
0.58
0.60
0.59
0.02
1.54
1.71
1.39
1.59
1.56
0.13
0.049
0.044
0.048
0.048
0.047
0.002
Post-
Decontamination
Activity
(uOCoupon)
0.86
0.91
0.86
0.89
0.88
0.02
0.28
0.27
0.29
0.30
0.28
0.01
0.83
0.82
1.01
0.87
0.88
0.09
0.012
0.010
0.021
0.015
0.015
0.005
%R
16%
5%
11%
11%
11%
4.3%
50%
56%
50%
50%
52%
3.1%
46%
52%
27%
45%
43%
11%
75%
77%
56%
69%
69%
9.5%
DF
.2
0.
2.0
2.3
2.0
2.0
2.1
0.1
1.9
2.1
1.4
1.8
1.8
0.3
4.0
4.3
2.3
3.2
3.4
0.9
As for the above testing, the cross-contamination blanks were included in the test stand during
testing with both contaminants to evaluate the potential for cross contamination due to
application of RDS 2000 on wall locations above the blank. Each cross contamination blank was
an uncontaminated concrete coupon that had pre-decontamination activity measurements
indicating extremely low background levels (below the detection limit) of activity. These
27
-------
coupons were decontaminated using RDS 2000 along with the other contaminated coupons. The
post-decontamination measurement of activity of these blanks was found to be undetectable for
any of the applicable radionuclides. Therefore, the cross contamination was not measurable
during application of RDS 2000.
5.1.6 Wash Aid Results
Table 5-8 presents the decontamination efficacy, expressed as both %R and DF, for Wash Aid
when decontaminating Cs-137 from concrete and asphalt surface coupons. The decontamination
efficacies of Wash Aid in terms of %R for Cs-137 were 24 ± 18% for decontamination of the
concrete surfaces and 36 ± 9% for decontamination of the asphalt surfaces. A t-test was
performed to determine the likelihood that the %R results between the two different surfaces
were all the same. The results indicated that the %R of Cs-137 from concrete and asphalt were
not significantly different from one another.
Table 5-8. Wash Aid Decontamination Efficacy for Removal of Cs-137 from Concrete and
Asphalt Results
Pre-Decontamination Post-Decontamination
Activity Activity
Surface Material (uOCoupon) (uOCoupon) %R DF
0.96
0.98
„ . 0.97
Concrete
0.95
Avg 0.97
SD 0.01
0.794
0.842
0.824
A U U °'787
Asphalt
0.791
Avg 0.81
SD 0.02
0.49
0.88
0.85
0.70
0.73
0.18
0.558
0.462
0.503
0.421
0.597
0.561
0.52
0.07
49% :
10%
12%
26%
24%
18% (
30%
45%
39%
47%
27%
29%
36%
9% (
>.o
.1
.1
.4
.4
).4
.4
.8
.6
.9
.4
.4
.6
).2
Table 5-9 presents the activity concentration of the Wash Aid effluents that were used to
decontaminate the concrete and asphalt surfaces. For concrete, the average pre-decontamination
activity was 0.97 jiCi per coupon and four concrete coupons (3.88 jiCi total) were rinsed with
Wash Aid with an average %R of 24%. Therefore, 24% of total activity (0.97 |iCi) should have
been present in the 12 L of Wash Aid used on the concrete coupons. This would correspond to
an activity concentration of 0.081 nCi/mL. The actual activity concentration measured in the
concrete Wash Aid effluent was 0.110 nCi/mL. For asphalt, the average pre-decontamination
activity was 0.81 jiCi per coupon and six concrete coupons (4.86 jiCi total) were rinsed with
Wash Aid with an average %R of 36%. Therefore, 36% of total activity (1.74 jiCi) should have
28
-------
been present in the 18 L of Wash Aid used on the concrete coupons. This would correspond to
an activity concentration of 0.097 nCi/mL. The actual activity concentration measured in the
concrete Wash Aid effluent was 0.143 nCi/mL. Therefore, both the concrete and the asphalt
Wash Aid effluents exhibited more Cs-137 than would have been expected. However, the
uncertainty in the average %Rs was 75% for concrete and 25% for asphalt (reasons for large
uncertainties may include coupon surface inconsistencies and approach to Wash Aid application)
so such a mass balance calculation should be considered an approximation.
5.1.7 Cs-13 7 Removal from Wash Aid Effluent with Vermiculite Clay
Table 5-9 presents the efficacy of vermiculite clay in removing Cs-137 from Wash Aid that had
been used to decontaminate concrete and asphalt coupons. The table gives the average initial
activity of the Wash Aid effluent collected following decontamination of four concrete coupons
and six asphalt coupons. The table also gives the average activity of the Wash Aid effluent after
three separate treatments with clay. The standard deviations of three replicate measurements
were very small so only the average activities were used to calculate the %Rs. From these data,
%Rs were calculated based on the initial activities before any clay treatment. For the concrete
Wash Aid effluent, the first treatment of clay resulted in a 46 %R, the second treatment of clay
resulted in a total %R of 69%, and the final treatment resulted in a final %R of 83%. For the
asphalt Wash Aid effluent, the first treatment of clay resulted in a 55 %R, the second treatment
of clay resulted in a total %R of 82%, and the final treatment resulted in a final %R of 92%.
Table 5-9. Cs-137 Removal from Wash Aid (with Vermiculite Clay) Results
Surface
Material
Concrete
Asphalt
Avg.
SD
Avg.
SD
Initial
(nCi/mL)
0.110
0.001
0.143
0.001
Post-clay
Addition #1
(nCi/mL)
0.059
0.005
0.065
0.003
%R
#1
46%
55%
Post-clay
Addition #2
(nCi/mL)
0.034
0.000
0.026
0.001
%R
#2
69%
82%
Post-clay
Addition #3
(nCi/mL)
0.018
0.001
0.011
0.000
Total
%R
83%
92%
5.2 Deployment and Operational Factors
Throughout the evaluation, technicians were required to use full anti-contamination personal
protective equipment (PPE) because the work was performed in a radiological enclosure using
Cs-137, Co-60, Sr-85 and Am-243 on the coupon surfaces. Whenever radiological material was
handled, anti-contamination PPE was required and any waste (e.g., from removal of the
decontamination technology foams and reagents) was considered at a minimum as low level
radioactive waste (and needed to be disposed of accordingly). The requirement for this level of
PPE was not driven by the use of the decontamination technologies (which are not hazardous),
but rather by the presence of Cs-137, Co-60, Sr-85 and Am-243.
5.2.1 DeconGel
A number of operational factors were documented by the technician who performed the testing
with DeconGel. The application process of DeconGel was described in Section 3.2.1 and
29
-------
included use of a standard 4-inch paint brush. DeconGel did not cause any visible damage to the
surface of the coupons. Table 5-10 provides some additional detail about the operational factors
for DeconGel as observed during the use of this experimental setup/test stand with relatively
small concrete coupons. The below information is applicable only to the experimental scenario
using small concrete coupons.
Table 5-10. Operational Factors of DeconGel
Parameter
Decontamination
rate
Applicability to
irregular surfaces
Skilled labor
requirement
Utilities
requirement
Extent of portability
Shelf life of media
Secondary waste
management
Surface damage
Cost
Description/Information
Coating preparation: Provided ready for use.
Application: Approximately 5 min and 375 mL per coat onto 0.2 square meter (m2)
for an application rate of 2.4 m2/hour and a DeconGel volumetric use rate of 1.9 L/m2
for each coat
Drying time: overnight
Removal time: 8 minutes for all nine coupons for a rate of 1.5 m2/hour
Estimated volume used per application of nine coupons (0.2 m2) included 375 mL
DeconGel.
Application to more irregular surfaces than what is encountered during this evaluation
would not seem to be much of a problem as a paint brush can reach most types of
surfaces as long as the operator can access the surfaces. DeconGel cures into a rather
rigid coating that was conducive for use on the surfaces made from concrete coupons
used during this evaluation.
After a brief training session to explain the procedures, most able-bodied people
would successfully perform both the application and removal procedures.
None was required in this case because a paint brush application was used.
According to the vendor, DeconGel can be applied using a paint sprayer.
With the exception of extreme cold, which would prevent the application of
DeconGel (which is water-based), its portability seems limitless.
Shelf life according to the manufacturer is five years.
Solid waste production: -200 g/m2for application of two coats
Not visible to the eye, removed only loose particles that were seen to be stuck to the
coating.
Material cost is $40/L for DeconGel which corresponds to approximately $76/m2 for
each coat if used in a similar way as used during this evaluation. Labor costs were not
calculated. Waste management costs were not included as they would be highly
dependent on the individual situation.
5.2.2 RRII
A number of operational factors were documented by the technician who performed the testing
with RRII. The application of RRII was described in Section 3.2 and included use of plastic
spray bottles. These application and removal times are applicable only to the experimental
scenario involving these rather small concrete coupons. According to the manufacturer, if RRII
was applied to larger surfaces, larger application tools such as larger sprayers or foamers would
likely be used which would impact the application rate. In addition, larger vacuum heads would
be used for removal. RRII did not cause any visible damage to the surface of the coupons.
Table 5-11 provides some additional detail about the operational factors for RRII as observed
using this experimental setup/test stand with relatively small concrete coupons.
30
-------
Table 5-11. Operational Factors of RRII
Parameter
Decontamination
rate
Applicability to
irregular surfaces
Skilled labor
requirement
Utilities
requirement
Extent of portability
Secondary waste
management
Surface damage
Cost
Description/Information
Technology Preparation: RRII is provided ready to use. The solutions (Formula 1
and Formula 2) were transferred into spray bottles and applied.
Application: Using this experimental setup, the initial application of RRII Formula 1
to the coupons took only seconds and then the coupons were kept damp (to simulate
the ongoing presence of a foam during a large-scale application) with reapplication
every 10 minutes during the dwell time. Following the 30 minute dwell time, rinsing
and vacuuming took approximately 25 seconds per coupon. This process was
repeated for RRII Formula 2. In all, the application and removal steps took 16
minutes in addition to the two 30 minutes dwell times for RRII. Aside from the dwell
times, this corresponds to a rate of approximately 0.8 m2/hour for RRII.
Estimated volumes used per application of nine coupons (0.2 m2) included 225 mL
RRII Formula 1, 250 mL RRII Formula 2, and 200 mL of the rinse solution.
Application to irregular surfaces would not seem to be problematic, RRII is easily
sprayed into hard to reach locations. Irregular surfaces may pose a problem for
vacuum removal.
Adequate training would likely include a few minutes of orientation so the technician
is familiar with the application technique including dwell times and requirement of
keeping the surface wet. Larger surfaces may require more complex equipment such
as spray or foam application.
Electricity for the wet vacuum. Larger surfaces may require more complex equipment
such as spray or foam application requiring additional utilities.
At a scale similar to that used for this evaluation, vacuum removal would be the only
portability factor. However, for larger scale applications, limiting factors would
include the ability to apply RRII at a scale applicable to an urban contamination (area
of city blocks or square miles) and then rinse and remove with a vacuum. Portable
electrical generation or vacuum capability may be required.
Approximately 675 mL of liquid was applied per nine coupons used during this
evaluation. That volume corresponds to a waste generation rate of approximately 3
L/m2 depending on how much of the solutions absorb to the surfaces. Waste solution
had to be neutralized from acidic pH before disposal.
Concrete and granite surfaces appeared to have a thin layer of residual RRII Formula
II left after the final rinse and removal. Initially it appeared as if the coupon just had
not fully dried after rinse, but close inspection revealed the residual material.
RRII solutions are not sold as a stand-alone product but are only available as a
decontamination service for which the cost varies greatly from project to project.
Typical projects costs are in the approximate range of $33-$55/m2.
5.2.3 ASG
A number of operational factors were documented by the technician who performed the testing
with ASG. Once fully mixed, ASG had the look of cooked oatmeal but was very "slippery" and
tended to slide off any plastic tools. ASG caused no visible damage to the surface of the
coupons. Table 5-12 provides some additional detail about the operational factors for ASG as
observed during the use of this experimental setup/test stand with relatively small concrete
coupons.
-------
Table 5-12. Operational Factors of ASG
Parameter
Decontamination
rate
Applicability to
irregular surfaces
Skilled labor
requirement
Utilities
requirement
Extent of portability
Secondary waste
management
Surface damage
Cost
Description/Information
Technology Preparation: 15 minutes to measure and mix powder with water.
ASG is able to be used for several days after mixing as long as ASG is kept
moist by covering the mixture as it will dry out if left exposed to air for several
days.
Application: ASG was applied with a four inch paint brush to each coupon in
approximately 30 seconds. After a 90 minute dwell time, ASG was removed
with a wet vacuum and the surface was wiped with a paper towel at a rate of
approximately 30 seconds per coupon (3 m /hour). Aside from the wait time
(which is independent of the surface area), the application and removal rate
was approximately 1 m2/hour. Estimated volumes used per nine coupons
included 2 L of ASG. Overall that volume corresponds to a loading of
approximately 10 L/m2.
Application to irregular surfaces may be problematic as ASG could slide off
jagged edges and be difficult to apply to hard to reach locations. During use
on the rough split face granite, a small amount of ASG could be seen
remaining in the crevices after vacuum removal.
Adequate training would likely include a few minutes of orientation so the
technician is familiar with the application technique. Larger surfaces may
require more complex equipment such as sprayer application.
As evaluated here, electricity was required to operate the wet vacuum. Larger
surfaces may require more complex equipment such as spray application
requiring additional utilities.
At a scale similar to that used for this evaluation, the only limitation on
portability would be the ability to provide vacuum removal in remote
locations. However, for larger scale applications, limiting factors would
include the ability to apply ASG at scale applicable to an urban contamination
(area of city blocks or square miles).
0.5-1 L of ASG was applied per nine coupons during this evaluation. That
volume corresponds to a waste generation rate of approximately 5 -10 L/m2.
ASG was collected entirely by the wet vacuum.
Concrete and granite surfaces appeared undamaged.
Material cost is approximately $0.30/L. This cost corresponds to $1.50 -
$3.00/m2 if used in a way similar to the process used during this evaluation.
Labor costs were not calculated. Waste management costs were not included as
they would be highly dependent on the individual situation.
5.2.4 LH-21
The application of LH-21 was described in Section 3.2.4 and included use of a plastic spray
bottle. According to the manufacturer, if LH-21 was applied to larger surfaces, larger application
tools such as larger sprayers or foamers would likely be used which would impact the application
rate. In addition, larger vacuum heads would be used for removal. LH-21 did not cause any
visible damage to the surface of the coupons.
Table 5-13 provides some additional detail about the operational factors for LH-21 as observed
using this experimental setup/test stand with relatively small concrete coupons.
32
-------
Table 5-13. Operational Factors of LH-21
Parameter
Decontamination
rate
Applicability to
irregular surfaces
Skilled labor
requirement
Utilities
requirement
Extent of portability
Secondary waste
management
Surface damage
Cost
Description/Information
Technology Preparation: Five minutes to dilute LH-21 1:1 with water and
transferred into spray bottle for application.
Application: Using this experimental setup, the initial application of LH-21 to
the coupons took only seconds and then the coupons were kept damp (to
simulate the ongoing presence of a foam during a large-scale application) with
reapplication every 10 minutes during the dwell time. Following the 60
minute dwell time, rinsing and vacuuming took approximately 45 seconds per
coupon. In all, the application and removal steps took 10 minutes in addition
to the 60 minute dwell time. Aside from the dwell time, this corresponds to a
decontamination rate of approximately 1 m2/hr for LH-21.
Estimated volumes used per application of nine coupons (0.2 m2) included 475
mL LH-21 and 200 mL of rinse water.
Application to irregular surfaces would not seem to be problematic, LH-21 is
easily sprayed into hard to reach locations. Irregular surfaces may pose a
problem for vacuum removal.
Adequate training would likely include a few minutes of orientation so the
technician is familiar with the application technique including dwell times and
requirement of keeping the surface wet. Larger surfaces may require more
complex equipment such as spray or foam application.
Electricity for the wet vacuum. Larger surfaces may require more complex
equipment such as spray or foam application requiring additional utilities.
At a scale similar to that used for this evaluation, vacuum removal would be
the only portability factor. However, for larger scale applications, limiting
factors would include the ability to apply LH-21 at a scale applicable to an
urban contamination (area of city blocks or square miles) and then rinse and
remove with a vacuum. Portable electrical generation or vacuum capability
may be required.
Approximately 675 mL of liquid was applied per nine coupons used during
this evaluation. That volume corresponds to a waste generation rate of
approximately 3 L/m2 depending on how much of the solutions absorb to the
surfaces.
No visible damage to the surface was observed.
Material cost is $1.50/L for the LH-21. This corresponds to approximately $47
m2 for LH-2 1 . Labor costs were not calculated. Waste management costs were
not included as they would be highly dependent on the individual situation.
5.2.5 RDS2000
The application of RDS 2000 was described in Section 3.2 and included use of a hand-pump
pressurized sprayer. These application and removal times are applicable only to the
experimental scenario involving these rather small concrete coupons. According to the
manufacturer, if RDS 2000 was applied to larger surfaces, larger application tools such as larger
sprayers or foamers would likely be used which would impact the application rate. In addition,
larger vacuum heads would be used for removal. RDS 2000 did not cause any visible damage to
the surface of the coupons.
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Table 5-14 provides some additional detail about the operational factors for RDS 2000 as
observed using this experimental setup/test stand with relatively small concrete coupons.
Table 5-14. Operational Factors of RDS 2000
Parameter
Decontamination
rate
Applicability to
irregular surfaces
Skilled labor
requirement
Utilities
requirement
Extent of portability
Secondary waste
management
Surface damage
Cost
Description/Information
Technology Preparation: 15 minutes to combine the two parts of the solution
and dilute the mixture to a 2% solution by volume.
Application: Using this experimental setup, the initial application of RDS
2000 to the coupons took only seconds followed by a light scrubbing and then
a five minute dwell time; a second RDS 2000 application, a water rinse and the
repeat of the 1st two applications ending with a water rinse and vacuum
removal. In all, the application and removal steps took 17 minutes including
the dwell times. Aside from the dwell time, this corresponds to a
decontamination rate of approximately 1 m /hour for RDS 2000.
Estimated volumes used per application of nine coupons (0.2 m2) included
approximately 1 L RDS 2000 and 1 L of rinse water.
Application to irregular surfaces would not seem to be problematic, RDS 2000
is easily sprayed into hard to reach locations. Irregular surfaces may pose a
problem for vacuum removal.
Adequate training would likely include a few minutes of orientation so the
technician is familiar with the application technique including dwell times and
requirement of keeping the surface wet. Larger surfaces may require more
complex equipment such as spray or foam application.
Electricity for the wet vacuum. Larger surfaces may require more complex
equipment such as spray or foam application requiring additional utilities.
At a scale similar to that used for this evaluation, vacuum removal would be
the only portability factors. However, for larger scale applications, limiting
factors would include the ability to apply RDS 2000 (including application and
scrubbing of surface) at a scale applicable to an urban contamination (area of
city blocks or square miles) and then rinse and remove with a vacuum.
Portable electrical generation or vacuum capability may be required.
Approximately 2 L of liquid was applied per nine coupons used during this
evaluation. That volume corresponds to a waste generation rate of
approximately 10 L/m2 depending on how much of the solutions absorb to the
surfaces.
No visible damage to the surface was observed.
Material cost is $15/L for the RDS 2000. This corresponds to approximately
$75/m2 for RDS 2000. Labor costs were not calculated. Waste management
costs were not included as they would be highly dependent on the individual
situation.
5.2.6 Wash Aid
Wash Aid was applied to concrete and asphalt surface material coupons with a very specialized
application setup. Such a setup was purely for technology evaluation purposes and in no way
was meant to mimic an actual decontamination scenario. Therefore, no additional operational
factors are provided. The Wash Aid effluent was solidified in super absorbing polymer and
disposed of as low-level radioactive waste.
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6.0 References
1. ASTM Standard C 150-07, 2007, "Standard Specification for Portland Cement," ASTM
International, West Conshohocken, PA, www.astm.org [accessed 9/13/13].
2. Radionuclide Detection and Decontamination Program, Broad Agency Announcement 03-
013, U.S. Department of Defense, Defense Advanced Research Projects Agency (DARPA)
and the U.S. Department of Homeland Security, classified program.
3. Calibration and Use of Germanium Spectrometers for the Measurement of Gamma Emission
Rates of Radionuclides, American National Standards Institute. ANSI N42.14-1999. IEEE
New York, NY (Rev. 2004).
4. U.S. EPA. CBI Polymers DeconGel® 1101 and 1108 for Radiological Decontamination.
U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/084, 2011.
5. U.S. EPA. Environmental Alternatives, Inc. Rad-Release I and II for Radiological
Decontamination. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-
11/083,2011
6. U.S. EPA. Argonne National Laboratory Argonne SuperGel for Radiological
Decontamination. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-
11/081,2011.
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Environmental Protection
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