EPA/600/R-12/067 | January 2013 | www.epa.gov/ord
United States
Environmental Protection
Agency
Technology Evaluation Report
CBI Polymers
DeconGel© 1108 for
Radiological Decontamination
of Americium
Office of Research and Development
National Homeland Security Research Center
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EPA/600/R-12/067
January 2013
Technology Evaluation Report
CBI Polymers
DeconGel® 1108 for Radiological
Decontamination of Americium
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency
26 Martin Luther King Drive
Cincinnati, OH 45268
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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 (NHSRC), funded and managed
this technology evaluation partially through Chemical, Biological, Radiological Nuclear Defense
Information analysis Center (CBRNIAC) Technical Area Task #794 (contract number SP0700-
OO-D-3180) and partially through contract No. EP-C-10-001 with Battelle. This report has been
peer and administratively reviewed and has been approved for publication as an EPA document.
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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FOREWORD
The U.S. Environmental Protection Agency (EPA) holds responsibilities associated with
homeland security events: EPA is the primary federal agency responsible for decontamination
following a chemical, biological, and/or radiological (CBR) attack. The EPA's Homeland
Security Research Program (HSRP) was established to conduct research and deliver scientific
products that improve the capability of the Agency to carry out these responsibilities.
An important goal of the HSRP's research is to develop and deliver information on
decontamination methods and technologies to clean up CBR contamination. When supporting or
directing such a recovery operation, EPA and other stakeholders must identify and implement
decontamination technologies that are appropriate for the given situation. The EPA's National
Homeland Security Research Center (NHSRC) has created the Technology Testing and
Evaluation Program (TTEP) in an effort to provide reliable information regarding the
performance of homeland security-related technologies. Through TTEP, the HSRP provides
independent quality assured performance information that is useful to decision makers in
purchasing or applying the tested technologies. Potential users are provided with unbiased, third-
party information that can supplement vendor-provided information. Stakeholder involvement
ensures that user needs and perspectives are incorporated into the test design so that useful
performance information is produced for each of the tested technologies. The technology
categories of interest include detection and monitoring, water treatment, air purification,
decontamination, and computer modeling tools for use by those responsible for protecting
buildings, drinking water supplies and infrastructure, and for decontaminating structures and the
outdoor environment.
The NHSRC is pleased to make this publication available to assist the response community to
prepare for and recover from disasters involving CBR contamination. This research is intended
to move EPA one step closer to achieving its homeland security goals and its overall mission of
protecting human health and the environment while providing sustainable solutions to our
environmental problems.
Jonathan G. Herrmann
National Program Director
Homeland Security Research Program
in
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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, Office of Research and Development (ORD)/NHSRC
Sang Don Lee, ORD/NHSRC
Scott Faller, Office of Air and Radiation (OAR)/Office of Radiation and Indoor Air (ORIA)
Terry Stilman, Region 4
Battelle Memorial Institute
United States Department of Energy's Idaho National Laboratories
IV
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Contents
Disclaimer ii
Foreword iii
Acknowledgments iv
Contents v
Abbreviations/Acronyms vii
Executive Summary viii
1.0 Introduction 1
2.0 Technology Description 3
3.0 Experimental Details 4
3.1 Experimental Preparation 4
3.1.1 Concrete Coupons 4
3.1.2 Coupon Contamination 5
3.1.3 Measurement of Activity on Coupon Surface 6
3.1.4 Surface Construction Using Test Stand 6
3.2 EvaluationofDGllOS 6
4.0 Quality Assurance/Quality Control 8
4.1 Intrinsic Germanium Detector 8
4.2 Audits 9
4.2.1 Performance Evaluation Audit 9
4.2.2 Technical Systems Audit 9
4.2.3 Data Quality Audit 10
4.3 QA/QC Reporting 10
5.0 Evaluation Results 11
5.1 Decontamination Efficacy 11
5.2 Deployment and Operational Factors 12
6.0 References 15
v
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Tables
Table 3-1.
Table 4-1.
Table 4-2.
Table 5-1.
Table 5-2.
Concrete Characterization 4
Calibration Results - Difference (keV) from Th-228 Calibration Energies 8
NIST-Traceable Eu-152 Activity Standard Check 9
Decontamination Efficacy Results 11
Operational Factors of DG 1108 14
Figures
Figure 2-1. DeconGel® 1108 3
Figure 3-1. Demonstration of contaminant application technique 5
Figure 3-2. Test stand with concrete coupons 6
Figure 5-1. Application and removal of DG 1108 12
Figure 5-2. Coupons before (left) and after (right) decontamination with DG 1108 13
VI
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Abbreviations/Acronyms
Am
ANSI
ASTM
Bq
CBR
cm
DARPA
DF
DG
DHS
EPA
Eu
g
IEEE
INL
keV
L
m
mL
mm
nCi
NHSRC
%R
PE
PPE
QA
QC
QMP
RML
RSD
ROD
RH
ISA
TTEP
Th
americium
American National Standards Institute
American Society for Testing and Materials
Becquerel(s)
chemical, biological, and/or radiological
centimeter(s)
Defense Advanced Research Projects Agency
decontamination factor
CBI Polymers DeconGel
U.S. Department of Homeland Security
U.S. Environmental Protection Agency
europium
gram(s)
Institute of Electrical and Electronics Engineers
Idaho National Laboratory
kilo electron volt(s)
liter(s)
meter(s)
milliliter(s)
millimeter(s)
nanoCuries(s)
National Homeland Security Research Center
percent removal
performance evaluation
personal protective equipment
quality assurance
quality control
quality management plan
Radiological Measurement Laboratory
relative standard deviation
radiological dispersal device
relative humidity
technical systems audit
Technology Testing and Evaluation Program
thorium
vn
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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 acts of terror by carrying out performance tests on homeland security technologies.
Through its Technology Testing and Evaluation Program (TTEP), the National Homeland
Security Research Center (NHSRC) evaluated the performance of the CBI Polymers (Honolulu,
HI) DeconGel® (DG) 1108. The objective of evaluating DG 1108 was to test its ability to remove
radioactive americium (Am)-243 from the surface of unpainted concrete.
DG 1108 is designed to be applied as a gel coating to bind the Am-243 physically and
chemically so that the Am-243 along with the cured coating can be removed from the surface
causing little or no surface damage. Prior to the evaluation of DG 1108, 15 centimeters (cm) x 15
cm unpainted concrete coupons were contaminated with Am-243 at an activity level of
approximately 50 nanoCuries (nCi), measured by gamma spectroscopy. The contaminated
coupons were then placed in a vertical test stand and, following manufacturer's
recommendations, two coats of DG 1108 were applied to all of the coupons in the test stand. The
coupons in the test stand were then allowed to dry overnight. The coating was then peeled from
the coupons and collected for disposal. This procedure was performed twice and then the
residual activity on the contaminated coupons was measured to determine the decontamination
efficacy achieved. This report documents the decontamination efficacy achieved along with
important deployment and operational factors determined based on the laboratory experience and
material properties. A summary of the evaluation results for DG 1108 is presented below.
Discussion of the observed performance can be found in Section 5 of this report.
Decontamination Efficacy: The decontamination efficacy (in terms of percent removal, %R)
attained by DG 1108 was evaluated following the contamination of the coupons with
approximately 50 nCi Am-243. These coupons were placed on a test stand to create a vertical
concrete surface to which DG 1108 was applied and removed. Overall, DG 1108
decontaminated the concrete coupons with an average %R of 84% + 5.7%. A limited evaluation
of cross contamination was performed, and the results confirmed that slight cross contamination
did occur.
Deployment and Operational Factors: DG 1108 is supplied "ready for use" as a coating with a
gel consistency somewhat more viscous than wall paint. DG 1108 was applied to the surfaces
with a standard 10 cm wide paint brush following the manufacturer's recommendation. The
concrete coupons used during this evaluation totaled 0.16 square meters (m2) and each
application (two coats) required three minutes for application of each coat separated by a two
hour drying time between coats. The DG 1108 was applied to a thickness sufficient to cover the
surface by visual inspection, but not so thick that the coating ran down the wall. Following the
two coat application, the DG 1108 was allowed to dry overnight and was then removed by
pulling the coating from the surface by hand (technician was in anti-contamination personal
protective equipment [PPE]). This two-coat application followed by removal was performed
twice. The combined time required to remove both applications of the coating was 17 minutes,
Vlll
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which translates to approximately 0.56 m per hour. The amount of waste generated (removed
coating) was 37 grams, or approximately 232 grams (g)/m2 for each two coat application. In
most cases, the DG 1108 was removed in a single piece from each coupon, but usually not across
the gaps between coupons (a distance of approximately 0.3-0.7 cm) that created an irregular
surface. The surface finish of the concrete was affected very little by the application and
removal of the DG 1108, as only very small pieces (~ 1 millimeter (mm) in length) of surface
concrete residue were visibly removed.
IX
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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, biological, or radiological contaminants into 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.
The National Homeland Security Research Center (NHSRC), 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. High-
quality information is provided that is useful to decision makers in purchasing or applying the
evaluated technologies. Potential users are provided 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.
The performance of the CBI Polymers DeconGel® 1108 strippable coating (DG 1108) for
decontamination of radioactive americium-243 (Am-243) from unpainted concrete was recently
evaluated. Americium was selected as a radiological contaminant because of its availability for
possible use in a radiological dispersal device (ROD) as the result of its common application in
smoke detectors. Concrete was selected as a surface because of its prevalence as a building
material. This evaluation was conducted according to a peer-reviewed test/QA plan entitled,
"The Performance of Strippable Coatings for Decontamination of Americium from Urban
Substrates", Version 1.0, dated November 21, 2011, that was developed according to the
requirements of the TTEP Quality Management Plan (QMP) Version 3, January 2008 (both are
available upon request. The following performance characteristics of DG 1108 were evaluated:
• Decontamination efficacy defined as the extent of radionuclide removal following two
cycles of application and removal of DG 1108. Another quantitative parameter evaluated
was the potential for cross contamination of adjacent uncontaminated surfaces due to the
decontamination procedure.
• Deployment and operational characteristics including rate of surface area
decontamination, applicability to irregular surfaces, skilled labor requirements, utilities
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requirements, extent of portability, shelf life of media, secondary waste management
including the estimated amount and characteristics of the spent media, and cost.
This evaluation took place in December 2011 at the U.S. Department of Energy's Idaho National
Laboratory (INL). This report describes the quantitative results and qualitative observations
gathered during this evaluation of DG 1108.
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2.0 Technology Description
This technology evaluation report provides results on the performance of DG 1108 under
laboratory conditions. The following is a description of DG 1108, based on unverified
information provided by CBI Polymers.
DG 1108 is a strippable coating designed for safely removing radioactive contamination from
surfaces or as a covering to contain contamination. DG 1108 is sold as a paint-like formulation
and 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. For
non-horizontal surfaces, the suggested number of coats is one or two coats for nonporous and
semiporous materials and up to four coats for porous surfaces such as concrete or wood, with
about two hours drying time between coats to ensure a final coating thickness sufficient to allow
the coating to be peeled. 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. More information is available at www.decongel.com [accessed 9/18/12],
Figure 2-1. DeconGel 1108.
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3.0 Experimental Details
3.1 Experimental Preparation
3.1.1 Concrete Coupons
The concrete coupons were prepared in a single batch of concrete made from Type II Portland
cement. The ready-mix company that supplied the concrete for this evaluation provided the data
shown in Table 3-1 about the cement clinker used in the concrete mix. The American Society
for Testing and Materials (ASTM) C1501 requirement for Type II Portland cement is that the
tricalcium aluminate is less than 8% of the overall cement clinker. As shown in Table 3-1 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.
Table 3-1. Concrete Characterization
Cement Constituent Percent of Mixture
Tricalcium Silicate 57.6
Dicalcium Silicate 21.1
Tricalcium Aluminate 4.5
Tetracalcium Aluminoferrite 8.7
Minor constituents 8_1
The wet concrete was poured into 0.9 m square plywood forms (approximately 4 cm deep) with
the surface exposed The surface was "floated" to allow the smaller aggregate and cement paste
to float to the top (the surface used for this evaluation), and the concrete was then cured for 21
days. Following curing, the 4 cm thick squares were cut with a laser guided rock saw to the
desired concrete coupon size of approximately 15 cm x 15 cm. The coupons had a surface finish
that was consistent across all the coupons. This concrete was judged to be representative of
exterior concrete commonly found in urban environments in the United States as shown by INL
under a previous U.S. Department of Defense, Defense Advanced Research Projects Agency
(DARPA) and U.S. Department of Homeland Security (DHS) project2.
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3.1.2 Coupon Contamination
Six contaminated coupons were spiked with 2.5 milliliters (mL) of unbuffered, slightly acidic
aqueous solution containing 20 nCi/mL Am-243 which corresponds to an activity level of
approximately 50 ± 5 nCi per coupon. Application of the Am-243 in an aqueous solution was
justified because even if Am-243 were dispersed in a dry particle form following an RDD event,
morning dew or rainfall would likely occur before the surfaces could be decontaminated. Such
an event would increase the likelihood that the Am-243 would no longer be bound to the
particles and that a chemical decontamination technology for decontaminating the concrete
surface would be preferable. In addition, from an experimental standpoint, the ability to apply
liquids homogeneously across the surface of the concrete coupons greatly exceeds that capability
for dry particles. The liquid spike was delivered to each coupon using an aerosolization
technique developed by INL under the DARPA/DHS project2 and described in detail in the
test/QA plan. Coupons were contaminated approximately two weeks before use and were stored
in a steel drum used for transport to the INL Radiological Measurement Laboratory (RML).
Storage conditions were not monitored during this time period, but aside from the vehicle
transport (a few hours) the drum remained unopened and located in working laboratories.
The aerosol delivery device was constructed of two syringes. The plunger and needle were
removed from the first syringe and discarded. Then a compressed air line was attached to the
rear of the syringe. The second syringe contained the contaminant solution and 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 1-2 liters (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 taped (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 3-1 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.
Figure 3-1. Demonstration of contaminant application technique.
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3.1.3 Measurement of Activity on Coupon Surface
Gamma radiation from the surface of each contaminated concrete coupon was measured to
quantify contamination levels both before and after use of DG 1108 on the coupons. These
measurements were made using an intrinsic high purity germanium detector (Canberra LEGe
Model GL 2825R/S, Meriden, CT). After being placed in the detector, each coupon was
measured until the average activity level of Am-243 from the surface stabilized to a relative
standard deviation (RSD) of less than 2%. Gamma-ray spectra acquired from Am-243
contaminated coupons were analyzed using the INL RML data acquisition and spectral analysis
programs. Radionuclide activities on 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 Q A/quality control (QC), as
described in the test/QA plan, was employed and certified results were provided.
3.1.4 Surface Construction Using Test Stand
To evaluate DG 1108 on vertical surfaces only (simulating walls), a stainless steel test stand that
held three rows of concrete coupons was used. The test stand was erected within a radiological
hood. As shown in Figure 3-2, three rows of two contaminated concrete coupons were placed on
the left side of the test stand and the uncontaminated coupon was placed on the right side of the
bottom row and treated with DG 1108 in the same way as the other coupons. This coupon,
referred to as the cross contamination blank, was used to observe possible cross contamination
caused by use of DG 1108 on contaminated surfaces adjacent to uncontaminated surfaces.
3.2 Evaluation of DG 1108
The seven concrete coupons in the test stand (six
contaminated and one blank) were decontaminated using DG
1108. The application of DG 1108 was performed using a
standard 10 cm paint brush. The specifications of the paint
brush were not critical as a perfectly smooth application was
not required. The paint brush was loaded by dipping the
brush into a plastic bag containing the wet DG 1108 and then
the wet DG 1108 was applied generously until the entire
surface of the coupon was covered. The wet DG 1108 was
then worked into the coupon surfaces by brushing in a circular
motion across the coupons. Then the brush was used to
smooth the applied DG 1108 on each concrete coupon. If
there were areas of the coupons that were not covered
completely, additional wet DG 1108 was added. The first
coat of DG 1108 was allowed to dry for 2 hours and a second coat was added on top of the initial
coat following the same procedure. The coupons were then allowed to dry overnight. Removal
of the dried DG 1108 was begun by pulling on the coating near the bottom of the coupons where
the gel thickness was greatest and then the broader surfaces could easily be started and removed
by hand. The application time included only the time for painting the coating onto the coupon
surface and then working the coating into the surface. The dry, removed coating from one of the
Figure 3-2. Test stand with
concrete coupons.
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DG 1108 applications was weighed to determine the amount of waste generation per unit area.
The overall decontamination method (two applications) for DG 1108 included:
1. Apply coating followed by two hour drying time and apply a second coat
2. Dry overnight
3. Remove dried coatings
4. Apply wet coating followed by two hour drying time and apply a second coat
5. Dry overnight
6. Remove final dried coatings.
The experimental timeline may be summarized as follows. The six coupons were contaminated
on November 30. The first application (two coats) of DG 1108 was completed on December 12
and allowed to dry overnight. The first removal of dried coating was performed on December 13.
The second and final application/removal cycle was performed in an identical way on December
13 and 14. Therefore, the final removal of DG 1108 was performed 15 days following
application of the Am-243 to the coupons. The temperature and relative humidity (RH) were
recorded during the application and removal of the DG 1108. Over the duration of testing, the
temperature and humidity in the laboratory where the coupons were stored and the evaluation
was performed was always within the range of 22-23°C and 16% RH respectively.
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4.0 Quality Assurance/Quality Control
QA/QC procedures were performed in accordance with the QMP and the test/QA plan for this
evaluation.
4.1 Intrinsic Germanium Detector
The germanium detector was calibrated weekly during the overall project. 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 gives the calibration results across
the duration of the project. Each row gives the difference between the known energy levels and
those measured following calibration (rolling average across the six most recent calibrations).
Pre-contamination measurements were performed in early December, and the post-contamination
results were measured mid December. Each row represents a six week rolling average of
calibration results. In addition, the energies were compared to the previous 30 calibrations to
confirm that the results were within three standard deviations of the previous calibration results.
All the calibrations fell within this requirement.
Table 4-1. Calibration Results - Difference (keV) from Th-228 Calibration Energies
Calibration Energy Levels in keV
Date Range
(2011)
10-18 to 11-22
10-24 to 12-6
11-1 to 12-13
11 -8 to 12-20
Energy 1
238.632
-0.002
-0.003
-0.001
-0.004
Energy 2
583.191
0.007
0.009
0.003
0.014
Energy 3
860.564
-0.002
-0.028
-0.010
-0.039
Energy 4
1620.735
-0.205
-0.160
-0.060
-0.278
Energy 5
2614.511
0.020
0.019
0.007
0.027
As described in the Quality Assurance Project Plan (QAPP), gamma ray counting was continued
on each coupon until the activity level of Am-243 on the surface had an 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
defines the full gamma counting QA process for certified results.
The background activity of the concrete coupons was determined by analyzing two arbitrarily
selected coupons from the stock of concrete coupons used for this evaluation. The ambient
activity level of these coupons was measured for one hour. No activity was detected above the
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minimum detectable level of 0.2 nCi on these coupons. Because the background activity was not
detectable (and the detectable level was approximately 10 times lower than the post-
decontamination activity levels), no background subtraction was required.
Throughout the evaluation, a second measurement was taken on two coupons to provide
duplicate measurements to evaluate the repeatability of the instrument. Both of the duplicate
pairs showed a difference in activity levels of 5% or less, at or within the acceptable range of
5%.
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-152 (Eu-152) standard (in units of Becquerels, Bq) and comparing the results to the
accepted NIST value. Results within 7% of the NIST value are considered to be within
acceptable limits as per the INL RML QC requirements. The Eu-152 activity comparison is a
routine QC activity performed by INL, but, for the purposes of this evaluation, serves 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 gives the
results of each of these audits of the detector that was used during this evaluation. All results are
within the acceptable difference of 7%.
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check
Date
12-15-2011
Eu-152
(keV)
Average
122
779
1408
NIST Activity
(Bq)
124,600
124,600
124,600
124,600
INL RML
Result (Bq)
122,600
118,900
122,200
118,700
Difference
0.5%
1.6%
1.3%
1.5%
4.2.2 Technical Systems Audit
A TSA was conducted during testing at INL to ensure that the evaluation was performed in
accordance with the test/QA plan and the TTEP QMP. As part of the audit, the actual evaluation
procedures were compared with those specified in the test/QA plan. In addition, the data
acquisition and handling procedures were reviewed. No significant adverse findings were noted
in this audit. The records concerning the TSA are stored indefinitely with the QA Manager.
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4.2.3 Data Quality Audit
At least 10% of the data acquired during the evaluation were audited. The QA Manager traced
the data 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 data undergoing
the audit were checked. No significant findings were noted.
4.3 QA/QC Reporting
Each assessment and audit was documented in accordance with the test/QA plan and the QMP.
There were two deviations from the test/QA plan during this evaluation. First, the target coupon
contamination levels were slightly outside the acceptable limits for two coupons. The upper
limit of the acceptable range was 55 nCi and two coupons had activities of 57 nCi and 58 nCi.
There was no negative impact to the evaluation due to this deviation because the levels were just
slightly outside the acceptable limits. Second, the test/QA plan stated that a single coupon test
stand would be used for strippable coating application. This text was included as a typographical
error as all parties involved understood that the expectation was that a multi-coupon test stand
would be used.
10
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5.0 Evaluation Results
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:
%R = (1-Af/Ao) x 100% and DF = A0/Af
where A0 is the radiological activity from the surface of the coupon before application of DG
1108, and Af is radiological activity from the surface of the coupon after removal of the
strippable coating. While the DFs are reported in the following data tables, the narrative
describing the results will focus on the %R.
Table 5-1 gives the %R and DF for DG 1108. The coupon position numbers indicate the
location within the surface (position 1-6) as defined in Figure 3-2. The activity for each of the
contaminated coupons (pre-decontamination) was between 48 nCi and 58 nCi. The overall
average (plus or minus one standard deviation) of the contaminated coupons was 53 +
3.1 nCi, a variability of 6%. The post-decontamination coupon activities were significantly less
than the pre-decontamination activities with an average %Rs of 84 ± 5.7%.
Table 5-1. Decontamination Efficacy Results
Coupon Position
Pre-
Decontamination
Activity
(nCi/coupon)
Post-
Decontamination
Activity
(nCi/coupon
%R
DF
1
2
3
4
5
6
Avg
SD
Cross contamination
blank
48
52
53
58
52
53
53
3
<0.2
6.9
7.4
6.1
6.8
8.8
14
8.4
3
1.3
86
86
89
88
83
73
84
6
NA
7.0
7.1
8.8
8.4
6.0
3.7
6.8
1.8
NA
NA-removal data not applicable to the cross contamination blank coupon
As described above in Section 3.1, the cross contamination blank was included in the test stand
to evaluate the potential for cross contamination due to application and removal of the DG 1108.
This coupon had not been contaminated, and pre-decontamination activity measurements
indicated extremely low background levels (below the 0.2 nCi detection limit) of activity. This
coupon was decontaminated using DG 1108 along with the other contaminated coupons. When
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all of the coupons were removed from the test stand following the two application and removal
cycles of DG 1108, the cross contamination blank coupon indicated an activity level that was 1.3
nCi, an activity of 1.1 nCi higher than the detection limit of the gamma counter (i.e., above
background). This increased level of activity, approximately 2% of the activity added to each of
the contaminated coupons (-50 nCi), was therefore not a large amount, but enough to note that
the possibility exists that cross contamination to locations previously not contaminated is a
possibility when using DG 1108 in a wide area application. The most likely route of cross
contamination would be contamination of the bulk DG 1108 during application with a paint
brush. However, another possible scenario would include touching the cross contamination
blank with a gloved hand that had just been used to apply or remove DG 1108 from the
contaminated coupons.
5.2 Deployment and Operational Factors
Table 5-2 summarizes various pieces of practical information (both qualitative and quantitative)
gained during the evaluation of DG 1108. A number of operational factors were documented by
the technician who performed the testing. The application process as described in Section 3.2
included application with a paint brush that was 10 cm wide. Three minutes was required to
apply each coat of DG 1108 to all seven coupons. The overall time required to remove the dried
coating from all seven coupons was 17 minutes. These application and removal times are
applicable only to the experimental scenario using small concrete coupons. If DG 1108 were to
be applied to larger surfaces, larger paint application tools such as rollers or sprayers would
likely be used. Use of rollers or sprayers would impact the application rate. In addition, larger
sections of dry coating could likely be removed in an amount of time similar to the amount of
time that was required for the small coupons.
Figure 5-1 shows the application and removal of DG 1108. In most cases during the evaluation,
the dry coating could be removed as one large piece from each coupon, but the dry DG 1108
generally could not be removed across the gaps between coupons of 0.3-0.7 cm. Figure 5-2
shows that the coupon surfaces were left largely unchanged by the DG 1108 as only very small
Figure 5-1. Application and removal of DG 1108.
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Figure 5-2. Coupons before (left) and after (right) decontamination with DG 1108.
pieces (~1 mm in length) of concrete residue were removed from the surface.
Technicians were required to use full anti-contamination PPE because the work was performed
in a radiological hood using Am-243. Whenever radioactively contaminated material is handled,
anti-contamination PPE is required and any waste (e.g. peeled coating) will be considered low
level radioactive waste and must be disposed of accordingly. The level of PPE required was not
driven by the use of DG 1108, which is not hazardous, but by the interaction with surfaces
contaminated with Am-243.
All of the operational information gathered during this evaluation was gathered during use of DG
1108 on relatively small surfaces (0.16 m2) that were built with concrete coupons. Some of the
information given in Table 5-2 could therefore differ if DG 1108 were to be applied to a larger
surface or to a surface with a significantly different surface texture or porosity.
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Table 5-2. Operational Factors for DG 1108
Parameter
Description/Information
Coating preparation: Provided ready for use.
Application: Approximately 3 minutes at 250 mL per coat onto 0.16 m2for an
application rate of 3.2 nrVhour and a DG 1108 volumetric use rate of 1.56 L/m2
for each coat
Drying time: overnight
Removal time: 17 minutes for all seven coupons for a rate of 0.56 m2/hour
Decontamination
rate
Application to more irregular surfaces than what was encountered during this
evaluation would not seem to be much of a problem as a paint brush can coat
most types of surfaces accessible to an operator. DG 1108 cures to a relatively
strong but flexible film that is conducive for use on the surfaces made from
concrete as were used during this evaluation. In most cases, DG 1108 was
removed coupon by coupon, but not across gaps between coupons.
Applicability to
irregular surfaces
Skilled labor After a brief training session to explain the procedures, no special skills would be
requirement required to successfully perform both the application and removal procedures.
Utilities
requirement
No utilities were required in this case because paint brush application was used.
DG 1108 can be applied using a paint sprayer which would require a minimum
of 120 Vac power.
Extent of portability
With the exception of extreme cold that would prevent the application of the
water-based DG 1108 the technology is not limited due to portability.
Shelf life of media Shelf life is advertised as one year.
Secondary waste
management
Solid waste production: approximately 464 g/m for two applications of two
coats
Surface damage
No visible surface damage; removed only loose particles that were consequently
stuck to the removed coating.
Cost
The material cost is approximately $40/L which corresponds to approximately
$240/m2 if used similarly to this evaluation. Labor costs were not calculated.
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6.0 References
ASTM Standard C 150-07, 2007, "Standard Specification for Portland Cement," ASTM
International, West Conshohocken, PA, www.astm.org [accessed 9/18/12].
Radionuclide Detection and Decontamination Program, Broad Agency Announcement 03-
013, U.S. Department of Defense (DOD) Defense Advanced Research Projects Agency
(DARPA) and the U.S. Department of Homeland Security.
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).
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United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development (8101R)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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