&EPA
www.epa.gov/nhsrc
technical BR
Evaluation of Chemical-Based Technologies for Removal of Radiological
Contamination from Building Material Surfaces
Background
Because of their potential for deployment as a terrorist
weapon in an urban setting, an improvised nuclear device
(IND) or radiological dispersion device (ROD, or "dirty bomb")
is a very real and significant danger. Cesium-137, Cobalt-60,
Strontium-85 or Americium-243 are some of the many
radioactive isotopes with the potential to be employed in an
IND or ROD. The National Response Framework, the federal
document that details how the nation responds to such
threats, identifies the U.S. Environmental Protection Agency
(EPA) as a lead federal agency for decontamination following
such a radiological incident. This response could include the
decontamination of buildings, equipment, and outdoor areas.
In support of this role, EPA's National Homeland Security
Research Center (NHSRC) evaluated the performance of
fourteen chemical-based decontamination technologies for
their ability to remove various radionuclides from the surface
of unpainted building materials. In addition, NHSRC
evaluated various deployment-related characteristics of the
products.
This work, completed in 2013, is described in a
series of reports. These peer-reviewed reports
provide rigorous evaluations of the efficacy of
fourteen commercially-available surface
cleaning technologies of the type that could be
employed to decontaminate concrete surfaces
following an ROD incident releasing
radioactive Cesium, Cobalt, Strontium, or
Americium. Results may be applicable to
contamination resulting from INDs and Nuclear
Power Plant (NPP) accidents. These reports,
which can be accessed via the NHSRC
website (www2.epa.gov/homeland-securitv-
research), provide information that emergency
responders and their support personnel can
use in recommending or selecting appropriate
technologies for use during cleanup
operations. This information can also be used
As part of U. S. EPA's Office of Research and
Development, the National Homeland Security Research
Center (NHSRC) provides products and expertise to
improve our nation's ability to respond to environmental
contamination caused by terrorist attacks on our nation's
water infrastructure, buildings and outdoor areas.
NHSRC conducts research related to:
• Detecting and containing contamination from
chemical, biological, and radiological agents
• Assessing and mitigating exposure to
contamination
• Understanding the health effects of
contamination
• Developing risk-based exposure advisories
• Decontaminating and disposing of
contaminated materials.
1
This document does not constitute nor should be construed as an EPA endorsement of any particular
product, service, or technology.
August 2015
EPA/600/S-15/155
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to assist federal, state, and local emergency management authorities and emergency
response planners to prepare for radiological homeland security events.
Results
A summary of the decontamination efficacy results is presented in Tables 1-4. Unpainted
concrete, limestone, granite, and marble coupons were contaminated with Cs-137, Co-60, Sr-
85, or Am-243 and the amount of contamination (radiological activity) deposited on each
coupon was measured. Each coupon was then treated with the decontamination technology
under investigation and the amount of contamination remaining was measured. Like all other
building materials, concrete was contaminated and decontaminated within two weeks or
decontaminated after one year ("Concrete-1Y" material in Tables 1-4). The efficacy of the
decontamination technology is expressed in terms of percent of contamination removed (%R).
These efficacy measures are determined based on the following relationship:
%R = (1-Af/A0) x 100%
%R = percent of contamination removed
Ao = radiological activity from the surface of the coupon before decontamination
Af = radiological activity from the surface of the coupon after decontamination
Decontamination results are tabulated per radionuclide (Table 1 for Cs-137; Table 2 for Co-60;
Table 3 for Sr-85; Table 4 for Am-243 and ordered per tested decontamination product. Not all
surface types were included for all fourteen decontamination technologies and four
radionuclides.
Operational-related characteristics are presented in Table 5.
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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Table 1. Efficacy of Decontamination Products for Removal of Cs-137
Product
EAI Rad- Release II
EAI SuperGel*
CBIDeconGel1108
Intek LH-21
SDF
UDF
CBI DeconGel 1101
EAI Rad-Release I
INTEK ND-75
INTEK ND-600
RDS Liquid
RDS Foam
RDS 2000
Application Type
Liquid Spray/Rinse/Vacuum
Gel/Vacuum
Strippable Coating
Liquid Spray/Rinse/Vacuum
Foam Spray/Vacuum/Rinse
Foam Spray/Vacuum/Rinse
Strippable Coating
Liquid Spray/Rinse/Vacuum
Liquid Spray/Rinse/Vacuum
Liquid Spray/Rinse/Vacuum
Liquid Spray/Wipe
Foam Spray/Wipe
Liquid Spray/Rinse/Vacuum
Reference
1,2
2
3
3
3
2,4
2
3
3
3
5
3
3
3
3
3
3
3
2
2
2
2
5
1
6
6
7
7
3
Material
Concrete
Concrete- 1Y
Limestone
Granite
Marble
Concrete
Concrete- 1Y
Limestone
Granite
Marble
Concrete
Limestone
Granite
Marble
Concrete
Limestone
Granite
Marble
Concrete
Concrete- 1Y
Concrete
Concrete- 1Y
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Decontamination Efficacy
%R
80 ±8
50 ±17
38 ±13
72 ±3
89 ±5
73 ±6
46 ±6
15±6
50 ±3
71 ±3
67 ±9
35 ±13
72 ±4
93 ±1
45 ±16
39 ±10
56 ±5
91 ±6
51 ±4
29 ±10
62 ±9
37 ±10
45 ±8
71 ±13
47 ±6
52 ±12
53 ±7
51 ±8
11±4
%R, percent of contamination removed
*: EAI SuperGel, developed by Argonne National Laboratories; previously tested as Argonne Supergel
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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Table 2. Efficacy of Decontamination Products for Removal of Co-60
Product
EAI Rad-Release II
EAI SuperGel*
CBI DeconGel 1108
RDS 2000
Application Type
Liquid Spray/Rinse/Vacuum
Gel/Vacuum
Strippable Coating
Liquid Spray/Rinse/Vacuum
Reference
8
8
8
8
3
3
Material
Concrete
Granite
Concrete
Granite
Concrete
Concrete
Decontamination Efficacy
%R
79 ±6
64 ±10
62 ±5
48 ±14
85 ±2
51 ±3
%R, percent of contamination removed
*: EAI SuperGel, developed by Argonne National Laboratories; previously tested as Argonne Supergel
Table 3. Efficacy of Decontamination Products for removal of Sr-85
Product
EAI Rad-Release II
EAI SuperGel*
CBI DeconGel 1108
RDS 2000
Application Type
Liquid Spray/Rinse/Vacuum
Gel/Vacuum
Strippable Coating
Liquid Spray/Rinse/Vacuum
Reference
8
8
8
8
3
3
Material
Concrete
Granite
Concrete
Granite
Concrete
Concrete
Decontamination Efficacy
%R
70 ±6
44 ±4
40 ±7
32 ±2
64 ±6
43 ±11
%R, percent of contamination removed
*: EAI SuperGel, developed by Argonne National Laboratories; previously tested as Argonne Supergel
Table 4. Efficacy of Decontamination Products for removal of Am-243
Product
EAI Rad-Release II
EAI SuperGel*
CBI DeconGel 11 08
RDS 2000
Intek LH-21
Bartlett Stripcoat
Application Type
Liquid Spray/Rinse/Vacuum
Gel/Vacuum
Strippable Coating
Liquid Spray/Rinse/Vacuum
Liquid Spray/Rinse/Vacuum
Strippable Coating
Reference
9
9
9
9
10
3
3
11
Material
Concrete
Granite
Concrete
Granite
Concrete
Concrete
Concrete
Concrete
Decontamination Efficacy
%R
88 ±5
51 ±3
67 ±9
34 ±2
84 ±6
69 ±10
87 ±7
46 ±5
%R, percent of contamination removed
*: EAI SuperGel, developed by Argonne National Laboratories; previously tested as Argonne Supergel
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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Table 5. Operational Characteristics
Parameter
Decontamination Rate
Applicability to irregular surfaces
Skilled labor requirement
Utilities required
Extent of portability
Setup time
Description
• EAI Rad-Release 1 and Rad-Release II: Applied usinq spray bottles in iust
seconds. Rad-Release 1 is a single step process requiring approximately 30
minutes dwell time. Rad-Release II is two-step process requiring a total of 60
minutes dwell time. Scale-up would require spray or foam generating
equipment, but dwell time would be the same.
• EAI SuperGel: Applied by trowel (paint scraper), scale-up would require spray
equipment (similar to airless paint sprayer) or roller. Requires 1 -2 hour dwell
time.
• DeconGel 1101 and 1108: Applied with paint brush, scale-up would require
spray equipment or roller. Requires overnight drying before stripping dry
coating. Curing of DeconGel 1 1 08 is faster at elevated temperatures and dry
conditions; when applied to wet surfaces curing may be delayed beyond 24 h
[12,13].
• INTEK LH-21, ND-75 and ND-600: Applied usinq spray bottles in iust
seconds. LH-21 requires six 10-minute application cycles. ND-75 requires
three 15-minute application cycles. ND-600 requires three 30-minute
application cycles. Scale-up would require spray equipment, but dwell times
would be the same.
• Allen-Vanquard Surface Decontamination Foam (SDF) and Decontamination
Formulation (UDF): Applied using a foamer in approximately one minute
followed by a 30 minute dwell time; vacuumed and reapplied foam for another
30 minutes. For UDF, additional reagent was sprayed with 30 minutes dwell
time. Scale-up would require spray or foam generating equipment, but dwell
time would be the same.
• RDS Liquid and Foam: Applied using spray/foam bottles in seconds.
Requires six cycles of application with two solutions and wiping with towels.
Required 3-6 minutes for each 225 cm2 concrete coupon.
• Karcher-Futuretech RDS 2000: Applied usinq hand pressurized sprayer in
seconds. Requires three application cycles with 5 minutes dwell times each.
• Bartlett Services Stripcoat TLC-Free™ : Two coatinqs applied two hours apart
with paint brush; scale-up would require spray equipment or roller. Requires
overnight drying before stripping the dry coating. Curing of Stripcoat TLC
Free™ is consistently 4 h and appears independent of environmental
conditions {5-40 °C; 20-80% RH) [12,13].
All technologies were judged to be applicable to irregular surfaces, but those
requiring vacuum removal (EAI products, INTEK products, SDF, UDF, and RDS
2000) may prove to be more difficult depending on the surface and available
vacuum attachments.
As evaluated, a brief training session is adequate. Scale-up would require
somewhat more complex equipment and/or contractor support with
corresponding training requirements for equipment operation.
1 10 V for vacuum; scale-up would require more complex equipment such as
sprayers.
Very portable; limited by need for utilities for vacuum and possible scaled-up
application tools.
Less than 15 minutes for all technologies as tested. Scaled-up application
would require increased setup time consistent with commercial spraying
equipment.
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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Parameter
Description
Secondary waste management
EAI Rad-Release I and Rad-Release II: Approximately 3-8 L/m2 liquid
collected by wet vacuum; less for porous materials.
EAI SuperGel: 5-10 L/ m2 gel waste collected in wet vacuum.
DeconGel 1101 and 1108: 200 g/m2 of dried coating
INTEK: Approximately 3-5 L/m2 liquid collected by the wet vacuum; less for
porous materials.
SDFandUDF: 25 L/m2 of foam and 15 L/m2 rinse water.
RDS Liquid and Foam: 5 L/m2 mostly collected by the towels used to wipe the
surface; 2000-3000 cm3 of towels used during this evaluation. Capacity of the
wipe material was not evaluated and may not scale linearly for a large scale
scenario.
RDS 2000: Approximately 10 L/m2 liquid collected by wet vacuum; less for
porous materials.
Stripcoat TLC-Free™: 400 g/m2 of dried coating.
So/face damage
None of the technologies caused visible surface damage.
Cosf (material only; does not include
labor, equipment, or waste
management)
EAI Rad-Release I and Rad-Release II: Approximately $33-55/m2
EAI SuperGel: Approximately $1.50-3.00/m2
DeconGel 1101 and 1108: Approximately $50-125/m2 (both 1101 and 1108)
INTEK: Approximately $1/m2 for ND-75; $2/m2 for ND-600; and $4/m2 for LH-
21
SDFandUDF: $8.25/m2forSDF; $12/m2forUDF
RDS Liquid and Foam: Approximately $250/m2
RDS 2000: Approximately $75/m2
Bartlett Stripcoat: Approximately $33/m2
Technology Evaluation Reports Referenced
1. U.S. EPA, Office of Research and Development, Environmental Alternatives, Inc. Rad-
Release I and II for Radiological Decontamination. U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-11/083, 2011.
2. U.S. EPA, Office of Research and Development, Decontamination of Concrete with
Aged and Recent Cesium Contamination. U.S. Environmental Protection Agency,
Washington, DC, EPA/600/R-13/001, 2013.
3. U.S. EPA, Office of Research and Development, Decontamination of Cesium, Cobalt,
Strontium, and Americium from Porous Surfaces. U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-13/232, 2013.
4. U.S. EPA, Office of Research and Development, Argonne National Laboratory Argonne
SuperGel for Radiological Decontamination. U.S. Environmental Protection Agency,
Washington, DC, EPA/600/R-11/081, 2011.
5. U.S. EPA, Office of Research and Development, CBI PolymersDeconGel® 1101 and
1108 for Radiological Decontamination. U.S. Environmental Protection Agency,
Washington, DC, EPA/600/R-11/084, 2011.
6. U.S. EPA, Office of Research and Development, INTEK Technologies ND-75 and ND-
600 for Radiological Decontamination. U.S. Environmental Protection Agency,
Washington, DC, EPA/600/R-11/085, 2011.
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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7. U.S. EPA, Office of Research and Development, Radiation Decontamination Solutions,
LLC "Quick Decon" Solutions for Radiological Decontamination. U.S. Environmental
Protection Agency, Washington, DC, EPA/600/R-11/086, 2011.
8. U.S. EPA, Office of Research and Development, Decontamination of Concrete and
Granite Contaminated with Cobalt-60 and Strontium-85. U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-11/086, 2011.
9. U.S. EPA, Office of Research and Development, Decontamination of Concrete and
Granite Contaminated with Americium-243. U.S. Environmental Protection Agency,
Washington, DC, EPA/600/R-13/204, 2013.
10. U.S. EPA, Office of Research and Development, CBI Polymers DeconGel® 1108 for
Radiological Decontamination of Americium. U.S. Environmental Protection Agency,
Washington, DC, EPA/600/R-12/067, 2013.
11. U.S. EPA, Office of Research and Development, Bartlett Services, Inc.Stripcoat TLC
FreeTMRadiological Decontamination of Americium. U.S. Environmental Protection
Agency, Washington, DC, EPA/600/R-13/005, 2013.
12. U.S. EPA, Office of Research and Development, Evaluation of the Curing Times of
Strippable Coatings and Gels as used for Radiological Decontamination. U.S.
Environmental Protection Agency, Washington, DC, EPA/600/R-14/238, 2014.
13. U.S. EPA, Office of Research and Development, Impact of Stagnant Air Flow Conditions
on the Curing Times of Strippable Coatings and Gels as used for Radiological
Decontamination. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-
15/171,2015.
Contact Information
For more information, visit the NHSRC Web site at www.epa.gov/nhsrc
Technical Contact: Lukas Oudejans (oudejans.lukas@epa.gov)
General Feedback/Questions: Kathy Nickel (nickel.kathy@epa.gov)
This document does not constitute nor should be construed as an EPA
endorsement of any particular product, service, or technology.
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