&EPA
EPA/600/R-08/099 I September 2008 I www.epa.gov/ord
United States
Environmental Protection
Agency
Bartlett Services, Inc.
Stripcoat TLC Free™
Radiological Decontamination
Strippable Coating
TECHNOLOGY EVALUATION REPORT
Office of Research and Development
National Homeland Security Research Center
-------
-------
EPA/600/R-08/099 I September 2008 I www.epa.gov/ord
Technology Evaluation Report
Bartlett Services, Inc.
Stripcoat TLC Free™
Radiological Decontamination
Strippable Coating
By:
Ryan R. James and Zachary J. Willenberg
Battelle
505 King Avenue
Columbus, OH 43201
Robert V. Fox
Idaho National Laboratory
P.O. Box 1625
MS 2208
Idaho Falls, ID 83415
John Drake
Task Order Project Officer
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency
26 Martin Luther King Drive
Cincinnati, OH 45268
-------
Notice
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 a Blanket Purchase Agreement under General
Services Administration contract number GS23F0011L-3 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.
-------
Preface
The U.S. Environmental Protection Agency (EPA) is charged
by Congress with protecting the nation's air, water, and
land resources. Under a mandate of national environmental
laws, the Agency strives to formulate and implement actions
leading to a compatible balance between human activities
and the ability of natural systems to support and nurture
life. To meet this mandate, the EPA's Office of Research and
Development (ORD) provides data and science support that
can be used to solve environmental problems and to build the
scientific knowledge base needed to manage our ecological
resources wisely, to understand how pollutants affect our
health, and to prevent or reduce environmental risks.
In September 2002, EPA announced the formation of the
National Homeland Security Research Center (NHSRC). The
NHSRC is part of the Office of Research and Development;
it manages, coordinates, supports, and conducts a variety of
research and technical assistance efforts. These efforts are
designed to provide appropriate, affordable, effective, and
validated technologies and methods for addressing risks
posed by chemical, biological, and radiological terrorist
attacks. Research focuses on enhancing our ability to detect.
contain, and decontaminate in the event of such attacks.
NHSRC's team of world renowned scientists and
engineers is dedicated to understanding the terrorist threat.
communicating the risks, and mitigating the results of
attacks. Guided by the roadmap set forth in EPA's Strategic
Plan for Homeland Security, NHSRC ensures rapid
production and distribution of security-related products.
The 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. TTEP provides independent, quality
assured performance information that is useful to decision
makers in purchasing or applying the tested 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 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. Additionally,
environmental persistence information is also important for
containment and decontamination decisions.
The evaluation reported herein was conducted by Battelle as
part of the TTEP program. Information on NHSRC and TTEP
can be found at http://www.epa. gov/nhsrc/.
-------
Acknowledgements
The authors wish to acknowledge the support of Dr. Howard Hall of the
Lawrence Livermore National Laboratory and Drs. Emily Snyder and Sang
Don Lee of the U. S. EPA National Homeland Security Research Center for
their review of the test/QA plan and this report.
-------
Contents
Notice ii
Preface iii
Acknowledgements iv
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 4
3.1.3 Measurement of Activity on Coupon Surface 5
3.1.4 Surface Construction Using Test Stand 5
3.2 Evaluation of Stripcoat 6
3.2.1 Application of Stripcoat 6
3.2.2 Progressive Decontamination Efficacy With Each Application of Stripcoat 7
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 10
4.2.3 Data Quality Audit 10
4.3 QA/QC Reporting 10
5.0 Evaluation Results 11
5.1 Decontamination Efficacy 11
5.1.1 7-Day Decontamination Efficacy Results 11
5.1.2 30-Day Decontamination Efficacy Results 12
5.1.3 Comparison of 7-Day and 30-Day Decontamination Efficacy 14
5.1.4 Progressive Decontamination Efficacy With Each Application of Stripcoat 14
5.2 Deployment and Operational Factors 15
5.2.1 Description of Application 15
5.2.2 Description of Removal 17
5.2.3 Miscellaneous Operational Information and Data 17
6.0 Performance Summary 20
6.1 Decontamination Efficacy 20
6.2 Deployment and Operational Factors 20
6.3 Conclusion 21
7.0 References... ....22
-------
Figures
Figure 2-1 Preparation, Application, and Removal of the Stripcoat 3
Figure 3-1 Concrete Coupons and Test Stand With the Contaminated Coupons Labeled "V"
for Vertical and "H" for Horizontal 6
Figure 5-1 Stripcoat After Application (left) and After Drying Overnight (right) 17
Figure 5-2 Stripcoat Removal 18
Tables
Table 3-1. Characteristics of the Portland Cement Clinker 4
Table 4-1. Calibration Results - Difference (keV) fromTh-228 Calibration Energies 8
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check 10
Table 5-1. 7-Day Decontamination Efficacy Results 12
Table 5-2. 30-Day Decontamination Efficacy Results 13
Table 5-3. Decontamination Efficacy With Each Application of Stripcoat 15
Table 5-4. Operational Factors Gathered from the Evaluation 18
-------
Abbreviations/Acronyms
BQ Bequerel
Cs cesium
cm centimeters
D&D decontamination and decommissioning
D ARPA Defense Advanced Research Proj ects Agency
DF decontamination factor
DHS U.S. Department of Homeland Security
DoD Department of Defense
EPA U.S. Environmental Protection Agency
Eu Europium
g gram
INL Idaho National Laboratory
ke V kilo electron volts
kg kilogram
mg milligram
mL milliliter
L liter
m meter
^Ci microcuries
NHSRC National Homeland Security Research Center
ORD Office of Research and Development
%R percent removal
PE Performance evaluation
psi pounds per square inch
Stripcoat Bartlett Services, Inc. Stripcoat TLC™ Free strippable coating
QA quality assurance
QC quality control
QMP quality management plan
ROD radiological dispersion device
RML Radiological Measurement Laboratory
TSA technical systems audit
TTEP Technology Testing and Evaluation Program
Th Thorium
-------
Executive Summary
The U.S. Environmental Protection Agency's (EPA's)
National Homeland Security Research Center (NHSRC)
Technology Testing and Evaluation Program (TTEP) 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.
Under TTEP, Battelle recently evaluated the performance
of Stripcoat TLCTM Free strippable coating (Stripcoat)
from Bartlett Services, Inc. (Plymouth, Massachusetts).
The objective of evaluating Stripcoat was to test its ability
to remove radioactive cesium (Cs)-137 from the surface of
unpainted concrete.
Stripcoat is applied as a paint-like coating and is then cured
in order to bind the Cs-137 physically so the cured coating
can be removed from the surface causing little or no surface
damage. Prior to the evaluation of Stripcoat, 15 cm x 15 cm
unpainted concrete coupons were contaminated with Cs-137
at a level of approximately 53 microcuries (uCi, measured
by gamma spectroscopy), then several of these contaminated
coupons were used within horizontal and vertical surfaces
constructed with 24 coupons.
Following manufacturer's recommendations, Stripcoat
was applied and removed three successive times before the
residual activity of the contaminated coupons was measured.
In addition, an evaluation of the decontamination efficacy
of Stripcoat was performed both 7 and 30 days following
application of the contaminant to the coupons. Results
include decontamination efficacies, a comparison of the
decontamination efficacy between the vertical and horizontal
surfaces, and a comparison between the 7-day and 30-day
results. Important deployment and operational factors were
also documented and reported. A summary of the evaluation
results for Stripcoat is presented below for each performance
parameter. Discussion of the observed performance can be
found in Section 5 of this report.
Decontamination Efficacy: The decontamination efficacy
expressed as percent removal, %R, attained by Stripcoat was
evaluated on separate concrete surfaces after both 7 days
and 30 days following the contamination of the coupons.
Overall, Stripcoat decontaminated the concrete coupons with
an average %R of 32.0 ± 9.9. The %Rs from the vertical and
horizontal surfaces were determined to be not significantly
different from one another. In addition, the %Rs between the
7-day and 30- day tests and between coupons placed on the
edge and within the other coupons were also determined to be
not significantly different from one another. Upon successive
Stripcoat application and removal cycles, 51% - 65% of the
Cs-137 removed during all three application cycles occurred
during the first application cycle.
Deployment and Operational Factors: Stripcoat is supplied
ready for use as a coating with a consistency similar to
wall paint. Stripcoat was applied, following manufacturer's
recommendation, to the surfaces with an airless paint
sprayer. The horizontal and vertical surfaces used during this
evaluation totaled l.lm2 and each complete application took
approximately 5 minutes. The objective of application was
to attain a layer of paint-like coating approximately 40 mils
thick. However, because a measurement of coating thickness
was not performed, a qualitative guideline was followed. The
coating was applied thick enough to cover the surface, but
not so thick that the coating ran down the wall. Following
application, the coating dried overnight and was removed
using a paint scraper. First, coupon edges were scored and the
coating was pulled from the surface. In most cases, Stripcoat
was removed in large pieces across the borders between
coupons. The Stripcoat removal rate was 4.9m2 per hour, the
rate of waste generation (removed coating) was 0.26 kg/m2.
and the volume of the waste was, on average, 0.145 g/cm3.
Cured Stripcoat was elastic and could be pressed together
into a sphere for disposal. In addition, Stripcoat was well
suited for rough or jagged surfaces as the cured coating was
easily removed across the borders of coupons (a distance of
approximately 0.3-0.7 cm) which created an irregular surface.
A limited evaluation of cross-contamination was performed.
and the results confirmed that cross-contamination did
occur. Any damage to the surface of the concrete caused by
Stripcoat was not visible to the naked eye.
Conclusion: Stripcoat removed approximately 32% of
the Cs-137 from the unpainted concrete coupons placed
together to form concrete surfaces with both horizontal and
vertical orientations. The Stripcoat worked the same in either
orientation and after 7 and 30 days following the application
of Cs-137 to the concrete coupons. Stripcoat can be applied
to irregular surfaces.The coating was elastic and easily
removed across the borders of the coupons.
-------
1.0
Introduction
The U.S. Environmental Protection Agency's (EPA's)
National Homeland Security Research Center (NHSRC) is
helping to protect human health and the environment from
adverse effects resulting from intentional acts of terror.
With an emphasis on decontam-ination and consequence
management, water infrastructure protection, and threat and
consequence assessment, NHSRC is working to develop
tools and information that will help detect the intentional
introduction of chemical or biological contaminants in
build-ings or water systems, the containment of these
contaminants, the decontamination of buildings and/or
water systems, and the disposal of material resulting
from clean-ups.
NHSRC's 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 the 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.
Under TTEP, Battelle recently evaluated the performance of
the Bartlett Services, Inc. Stripcoat TLC™ Free strippable
coating (Stripcoat) in decontaminating radioactive isotope
Cs-137 from unpainted concrete. This evaluation was
conducted according to a peer-reviewed test/QA plan(1)
that was developed according to the requirements of the
quality management plan (QMP) for TTEP(2) The following
performance characteristics of Stripcoat were evaluated:
• Decontamination efficacy defined as the extent of
radionuclide removal following application and removal
of Stripcoat.
• 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, the possibility of
cross-contamination, and the cost of using Stripcoat.
This evaluation took place from December 10, 2007 until
January 21, 2008. All of the experimental work took place
at U.S. Department of Energy's Idaho National Laboratory
(INL). This report describes the quantitative results and
qualitative observations gathered during this evaluation of
Stripcoat. Quality Assurance oversight of this evaluation was
provided by Battelle, INL, and EPA. Under the direction of
the Battelle QA manager, INL QA staff conducted a technical
systems audit (TSA) during the evaluation. The Battelle QA
Manager conducted a data quality audit of all evaluation data.
-------
-------
2.0
Technology Description
This technology evaluation report provides results on the
performance of Stripcoat TLCTM Free (Stripcoat) under
laboratory conditions. Following is a description of Stripcoat,
based on unverified information provided Bartlett Services,
Inc. (Plymouth, Massachusetts).
Stripcoat is a non-hazardous, non-toxic strippable coating
designed for safely removing radioactive contamination or
as a covering to contain contamination. Stripcoat is sold as
a paint-like formulation, therefore, use of a brush, roller,
or sprayer are all application options. The target thickness
during application was 40 mils. While curing, Stripcoat
mechanically entraps contamination. Following application,
the coating requires 4-10 hours to cure prior to removal.
After curing, the coating strips off along with surface
contamination. The manufacturer advises that Stripcoat
can also serve as a barrier to prevent contamination or as a
covering to contain contamination.
The below pictures are from the current evaluation. The
photo shown at the left of Figure 2-1 is the paint-like
formulation. The middle photo in Figure 2-1 shows the
application of Stripcoat to the concrete coupon surfaces.
The coating is then removed (Figure 2-1, right).
Figure 2-1. Preparation (left), Application (middle), and Removal of Stripcoat
-------
-------
3.0
Experimental Details
3.1 Experimental Preparation
3.1.1 Concrete Coupons
The concrete coupons were prepared from a single batch
of concrete made from Type II Portland cement3. Table
3-1 lists data provided by the ready-mix vendor about the
cement clinker used in the concrete mix. The ASTM C1503
requirement for Type II Portland cement specifies that
tricalcium aluminate be less than 8% of the overall cement
clinker. As shown Table 3-1, the cement clinker used for
the concrete coupons was 4.5% tricalcium aluminate. The
maximum allowable tricalcium aluminum content for Type
I is 15%, so the cement used during this evaluation mets the
specifications for both Type I and II Portland cements.
Table 3-1. Characteristics of the Portland Cement Clinker
Cement Constituent
Tricalcium Silicate
Dicalcium Silicate
Tricalcium Aluminate
Tetracalcium aluminoferrite
Minor constituents
Percent of Mixture
57.6
21.1
4.5
8.7
8.1
The wet concrete was poured into 0.9 meter (m) square
plywood forms with the surface exposed. The surface was
"floated" to get the smaller aggregate and cement paste to
float to the top, and then cured for 21 days. Following curing.
the squares were cut to the desired size with a laser guided
rock saw. For this evaluation, the "floated" surface of the
concrete coupons was used. The coupons were approximately
4 centimeters (cm) thick, 15 cm square, and had a surface
finish that was consistent across all the coupons and that was
representative of exterior concrete commonly found in urban
environments in the U.S. 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) project4.
3.1.2 Coupon Contamination
Each contaminated coupon was spiked with 2.5 milliliters
(mL) of unbuffered, slightly acidic aqueous solution
containing 137 milligrams (mg)/ liter (L) Cs-137
corresponding to an activity level of approximately
53 uCi over the 225 cm2 surface. Application of the
Cs-137 in an aqueous solution was justified because even
if Cs-137 was dispersed in a particle form following an
RDD event, morning dew or rainfall would likely occur
before the surfaces could be decontaminated. In addition.
the ability to apply liquids homogeneously across the
surface of the concrete coupons greatly exceeds that for
particles. The liquid spike was delivered to each coupon
using an aerosolization technique developed by INL under
the DARPA/DHS project4. The aerosol deli device is
constructed of two syringes. The first syringe had the plunger
removed and a nitrogen gas line was attached to the rear of
the syringe. The second syringe contained the contaminant
spiking solution and was equipped with a 27 gauge needle
which penetrated through the plastic housing near the tip
of the first syringe. Nitrogen gas was turned on at a flow of
approximately 1-2 liters per minute, creating a turbulent
flow through the first syringe. The liquid spike in the second
syringe was introduced and then nebulized by the turbulent
gas 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. Coupon edges were taped
and sealed with epoxy to ensure that the contaminant was
applied only to the surfaces. Contaminant was sprayed to the
edges of the coupons.
3.1.3 Measurement of Activity on Coupon Surface
Measurement of gamma radiation from the surface of
concrete coupons was used to quantify contamination levels
before and after application of the strippable coating. These
measurements were made using one of three identical
intrinsic, high purity germanium detectors following
contamination and after application of Stripcoat. After being
placed into the detector, each coupon was measured until the
average activity level of Cs-137 from the surface stabilized
to a relative standard deviation of less than 2%. Gamma-ray
spectra acquired from Cs-137 spiked coupons were analyzed
using the INL Radiological Measurement Laboratory (RML)
data acquisition and spectral analysis programs. Radionuclide
activities on coupons were calculated based on the efficiency.
emission probability, and half-life values. Decay corrections
were made based on reference time and date and the duration
of the counting period. Full RML gamma counting QA/
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 the decontamination technologies on vertical
surfaces (simulating walls) as well as horizontal surfaces
(simulating sidewalks and drives), a test stand was fabricated
that held four rows of six concrete coupons to create
surfaces that were approximately 90 cm wide x 60 cm deep
(horizontal) or tall (vertical). Six of the 24 coupons used
to construct each surface were contaminated with Cs-137.
Figure 3-1 shows a picture of several concrete coupons
and a test stand loaded with the concrete coupons. After
the coupons were contaminated with Cs-137, some were
allowed to age for 7 days and some for 30 days prior to their
placement in the test stand for application and removal of
Stripcoat. The two different timeframes were used to evaluate
-------
Figure 3-1. Concrete Coupons (left) and Test Stand With the
Contaminated Coupons Labeled "V" for Vertical and "H" for Horizontal (right)
the effectiveness of decontamination technologies within one
week of a radiological incident and within one month. Within
the surfaces on the test stand, the six contaminated coupons
were arranged so that one coupon was on each side edge.
one was on the top edge, and several were not on an edge at
all. Figure 3-1 shows the pattern of contaminated coupons
on each surface. The coupon codes indicate the orientation
of each coupon (H-horizontal and V-vertical) as well as the
location within the surface (position A-E). The top surface of
the coupons were not labeled during the evaluation.
3.2 Evaluation of Stripcoat
5.2.1 Application of Stripcoat
The decontamination process was begun 7 days (7-day test
) following the application of the Cs-137 to the concrete
coupons. Three application and removal cycles were
completed before the final measurement of residual activity
was made. To summarize the timeline, the 7-day coupons
were contaminated on December 3, then included in the
construction of the vertical and horizontal surfaces. The
first application of Stripcoat was made to the surfaces on
December 10 and allowed to dry overnight, the first removal
of Stripcoat was performed on December 11, the second
application/removal cycle was performed on December
11 and 12, and the final application/removal cycle was
performed on December 12 and 13. Therefore, the final
removal of Stripcoat was performed 10 days following
application of the Cs-137 to the coupons. In a similar way.
the 30-day coupons were contaminated on December 17 and
the first of three applications of Stripcoat was performed
on January 16 and completed over the next several days.
Following the final removal of Stripcoat, the contaminated
coupons were removed from the surfaces and residual
activity measured.
The temperature and relative humidity were recorded during
both the 7-day and 30-day tests. These conditions did not
vary significantly in the laboratory where the coupons were
stored and the evaluation was performed. Over the duration
of testing, the temperature was always within the range of
23-26°C and the relative humidity was always within the
range of 11-17%.
5.2.2 Progressive Decontamination Efficacy With Each
Application of Stripcoat
The focus of this evaluation was determining the overall
decontamination efficacy of Stripcoat following three
separate applications. The test plan called for the Stripcoat to
be applied and removed three times before measurement of
the residual activity. However, as a side experiment during
the evaluation, a few coupons were measured following each
application and removal of Stripcoat to determine the degree
of decontamination that occurred with each application
and removal of Stripcoat. The progressive decontamination
efficacy was determined using two and three coupons and for
the 7- and 30-day tests, respectively. Only two coupons were
analyzed for the 7-day test because of the limited availability
of contaminated coupons. These coupons had been
contaminated as extra contaminated coupons, in case of an
accidental breakage. These coupons were set in a horizontal
orientation to the side of the test stand and the Stripcoat was
applied and removed as for the rest of the coupons on the
test stand. These coupons were transported to the RML for
activity measurement four times, once upon application of
Cs-137 and once following each of three applications and
removals of Stripcoat.
-------
4.0
Quality Assurance/Quality Control
QA/quality control (QC) procedures were performed in
accordance with the program QMP(2) and the test/QA plan(1)
for this evaluation.
4.1 Intrinsic Germanium Detector
Calibrations of intrinsic, high purity germanium detectors
were established using standardized procedures from
American National Standards Institute and the Institute of
Electrical and Electronics Engineers5. 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). This calibration was performed weekly and
documented by the RML. Table 4-1 shows the results of the
calibrations by giving the difference in the energies between
the known energy levels and those measured following
calibration. The calibrations are shown for each of the three
detectors used during this evaluation. The energies were
compared to the previous 30 calibrations. The operator
alerted if the results exceeded three standard deviations of the
other calibration results. The calibrations are shown for each
of the three detectors used during this evaluation. None of
these calibrations exceeded that threshold.
For each measurement of activity on each coupon, gamma
ray counting continued until the activity level of Cs-137 on
the surface had a relative standard deviation of less than 2%.
The final activity assigned to that coupon was a compilation
of information obtained from all components of the electronic
assemblage which comprises the "gamma counter," including
the raw data and the spectral analysis conducted by the
spectroscopist using an INL data analysis program. Final
spectra and all data which comprise the spectra were sent to
a data analyst who independently confirmed the "activity"
number determined by the spectroscopist. When both the
spectroscopist and an expert data analyst independently
arrived at the same number, then the data were certified. This
entire process defines the full gamma counting QA process
for certified results.
The background activity of the concrete coupons was
determined by the analysis often arbitrarily selected coupons
from the stock of concrete coupons. The ambient activity
level of these coupons was measured for two hours and the
activity for all of the coupons was determined to be below
the minimum detectable level of 2xlO~4 uCi. Because the
background activity was not detectable, and the detectable
level was more than 5,000 times lower than the post-
decontamination activity levels, no background subtraction
was required.
Throughout the evaluation, 12 contaminated coupons were
measured as duplicate analyses. Four duplicate analyses each
were completed for three sample sets including coupons that
had been contaminated, coupons decontaminated during the
7-day test, and coupons decontaminated during the 30-day
test. Three of the duplicate samples showed no difference
from the original measurement while the average percent
Table4-1. Calibration Results- Difference (keV) from Th-228 Calibration Energies
Calibration Energy Levels in keV
Date
11-6-2007
12-3-2007
12-11-2007
12-18-2007
1-15-08
1-22-08
Detector
1
4
5
1
4
1
4
1
4
1
4
1
4
Energy 1
238.632
-0.002
-0.004
-0.002
0.000
-0.006
-0.002
-0.004
-0.003
-0.003
-0.003
-0.004
-0.006
-0.003
Energy 2
583.191
0.008
0.022
0.007
0.002
0.022
0.008
0.014
0.012
0.013
0.012
0.018
0.022
0.011
Energy 3
860.564
-0.004
-0.119
-0.006
-0.025
-0.076
-0.040
-0.041
-0.026
-0.063
-0.042
-0.069
-0.022
-0.032
Energy 4
1620.735
-0.206
-0.028
-0.193
0.028
-0.170
-0.108
-0.194
-0.273
-0.135
-0.190
-0.211
-0.390
-0.169
Energy 5
2614.511
0.022
0.013
0.019
-0.001
0.034
0.011
0.025
0.028
0.018
0.022
0.024
0.055
0.021
-------
difference between the original and duplicate measurements
was 0.71%, within the acceptable difference of 3%.
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 NIST-traceable Eu-152 standard (in units of
Bequerel, BQ) and comparing 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 quality control activity performed by INL. For
the purposes of this evaluation, the calibration serves as the
performance evaluation (PE) audit that confirms the accuracy
of the calibration standards used for the instrumentation
critical to the results of our evaluation. Table 4-2 gives the
results of each of these audits for each detector that was used
during this evaluation. All results are within the acceptable
difference of 7%.
4.2.2 Technical Systems Audit
A technical systems audit was conducted during testing
at INL to ensure that the evaluation was performed in
accordance with the test/QA plan« and the TTEP QMPS2>
As part of the audit, the actual evaluation procedures were
compared with those specified in the test/QA plan(1). 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 Battelle Quality Assurance Manager.
One test/QA plan deviation occurred during this evaluation.
Instead of a 0.25 mL volume of Cs-137 spiking solution as
was stated in the test/QA plan, a 2.5 mL volume was used in
order to attain a more homogeneous coverage across each
coupon. The evaluation was not negatively impacted.
4.2.3 Data Quality Audit
At least 10% of the data acquired during the evaluation were
audited. The Battelle Quality Assurance 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.
4.3 QA/QC Reporting
Each assessment and audit was documented in accordance
with the test/QA plan(1) and the QMP.(2) Once the assessment
report was prepared by the Battelle Quality Assurance
Manager, the report was routed to the Test Coordinator and
Battelle TTEP Program Manager for review and approval.
The Battelle Quality Assurance Manager then distributed
the final assessment report to the EPA Quality Manager and
Battelle staff.
There was one deviation from the test/QA plan during this
evaluation. Instead of a 0.25 mL volume of Cs-137 spiking
solution as was stated in the test/QA plan, a 2.5 mL volume
was used in order to attain a more homogeneous coverage
across each coupon. There was no negative impact to the
evaluation.
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check
INL RMLResult
Date Detector
11-11-2007
11-13-2007
12-11-2007
1-15-2008
4
1
5
1
4
1
4
NIST Activity (BQ)
124,600
124,600
124,600
124,600
124,600
124,600
124,600
(BQ)
130,300
122,900
124,700
122,400
128,900
122,000
129,300
Difference
5%
1%
0%
2%
3%
2%
4%
-------
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 = (l-Af/Ao) x 100% and DF = A/Af
where Ao is the radiological activity from the surface of
the coupon before application of Stripcoat and Af is
radiological activity from the surface of the coupon after
removal of the strippable coating. The DFs are reported in the
following data tables, but for the sake of brevity, the narrative
describing the results will focus on the %R. The following
sections describe the performance of Stripcoat 7 and 30 days
after contaminant application and on horizontal and vertical
surfaces. Throughout the evaluation, Microsoft® Excel
was used to perform paired t-tests in order to determine if
significant differences existed within the data set. In all cases.
the t-tests were two-tailed and were conducted at the 95%
confidence interval.
5.1.1 7-Day Decontamination Efficacy Results
Table 5-1 gives the %R and DF for Stripcoat after a 7-day
time period between coupon contamination and use of
Stripcoat. The coupon codes indicate the orientation of each
coupon (H-horizontal and V-vertical) as well as the location
within the surface (position A-E) as shown in Figure 3-1.
The target activity for each of the contaminated coupons
(pre-decontamination) was within the acceptable range
of 53 uCi ±5.3 uCi. The overall average (plus or minus
one standard deviation) of the contaminated coupons was
56.8 uCi ± 1.7 uCi for the horizontal surface, 53.5 uCi ±
1.7 uCi for the vertical surface, and 55.2 uCi ± 2.4 uCi
across all the coupons in both surfaces, a variability of 4%.
Evaluating Stripcoat for its effectiveness in the horizontal
and the vertical orientations was an important objective for
this evaluation. Because Stripcoat is applied as a liquid.
this evaluation sought to find out if the coating adhered
adequately to the wall to accomplish decontamination with
similar efficacies as in the horizontal orientation. The post-
decontamination coupon activities were significantly less
than the pre-decontamination activities. For the horizontal
Table 5-1. 7-Day Decontamination Efficacy Results
Coupon
Code
Horizontal
Vertical
Overall
HA
HB
HC
HD
HE
HF
Avg
SD
VA
VB
VC
VD
VE
VF
Avg
SD
Avg
SD
Pre-Decon Activity
|jCi /Coupon
57.7
57.9
53.8
55.8
57.8
57.9
56.8
1.7
56.3
52.2
52.6
51.7
53.5
54.6
53.5
1.7
55.2
2.4
Post-Decon Activity
uCi / Coupon
42.9
42.4
41.7
33.8
35.5
33.5
38.3
4.5
38.9
27.9
39.7
41.3
41.5
41.8
38.5
5.3
38.4
4.7
%R
25.6
26.8
22.5
39.4
38.6
42.1
32.5
8.5
30.9
46.6
24.5
20.1
22.4
23.4
28.0
9.8
30.3
9.0
DF
1.3
1.4
1.3
1.7
1.6
1.7
1.5
0.2
1.4
1.9
1.3
1.3
1.3
1.3
1.4
0.2
1.5
0.2
-------
and vertical surfaces, the %Rs (defined in Section 5.1) were
32.5 ± 8.5 and 28.0 ± 9.8. These %Rs were determined to be
not significantly different by a paired t-test analysis (p=0.52).
indicating that the decontamination efficacy of Stripcoat
in the horizontal and vertical orientations was similar. The
overall average %R for the 7-day test was 30.3 ± 9.0.
The contaminated coupons that were included in the surfaces
were placed at various locations across the surface and
various paired t-tests were performed to allow observation
of whether or not location on the surface affected the
decontamination efficacy. Within the 7-day coupons, coupons
that were on the edge (horizontally and/or vertically)
of the surfaces were compared with those not on the
edges (horizontally and/or vertically) to see if significant
differences existed. During the 7-day test, no such differences
were identified, therefore, Stripcoat performed equally on the
vertical and horizontal surfaces whether the coupons were
located on an edge or not.
5.1.2 30-Day Decontamination Efficacy Results
Table 5-2 gives the %R and DF for Stripcoat after a 30-day
time period between contaminant application and use of
Stripcoat. As with the 7-day results, the target activity for
each of the contaminated coupons (pre-decontamination)
Table 5-2. 30-Day Decontamination Efficacy Results
was within the acceptable range of 53 uCi ±5.3 uCi. The
overall average (plus or minus one standard deviation)
of the contaminated coupons was 53.2 uCi ±3.0 uCi for
the horizontal surface, 55.6 uCi ± 1.4 uCi for the vertical
surface, and 54.4 uCi ± 2.6 uCi across all the coupons in
both surfaces, a variability of 5%.
The post-decontamination coupon activities were
significantly less than the pre-decontamination activities.
For the horizontal and vertical surfaces respectively, the
%Rs (defined in Section 5.1) were 35.8 ± 8.7 and 31.9 ±
13.0. These were determined to be not significantly different
by a paired t-test analysis (p=0.56), indicating that the
decontamination efficacy of Stripcoat in the horizontal and
vertical orientations was similar. The overall average %R for
the 30-day test was 33.8 ± 10.7.
As with the 7-day coupons, the contaminated coupons
included in the surfaces were placed at various locations
across the surface and various paired t-tests were performed
to determine if location within the surface affected the
decontamination efficacy. As for the 7-day test, no differences
were identified in decontamination efficacy during the 30-day
test, therefore, Stripcoat performed equally on the vertical
and horizontal surfaces and when the coupons were located
on the edge or not.
Coupon Code
Horizontal
Vertical
Overall
HA
HB
HC
HD
HE
HF
Avg
SD
VA
VB
VC
VD
VE
VF
Avg
SD
Avg
SD
Pre-Decon Activity
|jCi / Coupon
55.6
55.2
50.8
48.7
52.6
56.2
53.2
3.0
54.8
54.3
57.1
56.3
54.1
57.0
55.6
1.4
54.4
2.6
Post-Decon Activity
uCi / Coupon
41.7
39.9
29.8
31.9
27.0
35.2
34.3
5.8
33.1
48.1
43.7
29.0
36.6
36.4
37.8
7.0
36.0
6.4
%R
25.0
27.7
41.3
34.5
48.7
37.4
35.8
8.7
39.6
11.4
23.5
48.5
32.3
36.1
31.9
13.0
33.8
10.7
DF
1.3
1.4
1.7
1.5
1.9
1.6
1.6
0.2
1.7
1.1
1.3
1.9
1.5
1.6
1.5
0.3
1.5
0.2
-------
5.1.3 Comparison of 7-Day and 30-Day
Decontamination Efficacy
Given there were no significant differences determined
between the horizontal and vertical surfaces during the
7-day or 30-day tests, the overall average %Rs can
be compared to determine if Stripcoat performed differently
during the two sets of experiments. The overall averages
%R for the 7-day and 30-day tests were 30.3 ± 9.0 and
33.8 ± 10.7, respectively, suggesting that the increased
time of the contaminant binding to the concrete surface
caused a slightly decreased %R. However, a paired t-test
determined that these two averages were not significantly
different from one another at the 95% confidence interval
(p=0.45). This difference is not significant because the
standard deviations of the post-decontamination activity
measurements across several coupons increased significantly
compared with the pre-decontamination measurement of
activity across the same coupons. This increase indicated the
somewhat variable efficacy of the Stripcoat in removing Cs-
137 from the surface of the concrete.
In addition to the comparison of overall average, various
paired t-tests were performed including data from both the
7-day and 30-day tests to allow observation of whether or
not location within the surface impacted the decontamination
efficacy. The increased number of data points improved
statistical power in determining significant differences in the
data. Thus, all of the vertical and horizontal coupons, edge
and non-edge, from both tests were compared to determine
if significant differences existed. However, out of these
analyses, no comparisons generated a significant difference
from the rest of the data set. Therefore, Stripcoat performed
statistically similar during the 7- and 30-day tests when the
coupons were in the vertical and horizontal orientations and
whether or not they were among other coupons within the
surfaces or on the edge of the surfaces.
5.1.4 Progressive Decontamination Efficacy With Each
Application of Stripcoat
As described previously, three application cycles of were
completed for each test. Therefore, a few coupons were
measured after each application/removal cycle to determine
the level of decontamination with each cycle. Table 5-3
shows the results from each measurement of activity starting
with the initial measurement prior to the first application and
removal of Stripcoat through three successive applications
and removals of Stripcoat. Table 5-3 also shows the total
%R (additive across applications), the %R attributed to each
successive application, and the percent of the total removal
attributable to each application cycle. For example, of the
16.6 %R that was attained for the first 7-day coupon, 10.1%
was attained with the first application. Overall, the first
application corresponded to 61.2% of the total removal from
that coupon.
The results indicated that most of the decontamination
occurs with the first application and removal cycle of
Stripcoat. While only five coupons were tested in this
fashion, the results were consistent. More than half of the
decontamination occurred with the first application cycle.
Thereafter, about half of the remaining removal occurred
during each of the two final application and removal cycles.
The percent of total removal with the first cycle ranged from
51-65%, 16%-26%forthe second cycle, and 12%-34%
for the third and final cycle of application and removal of
Stripcoat. An experimental design more focused on this
aspect of Stripcoat's performance would be required to
make additional conclusions.
5.2 Deployment and Operational Factors
5.2.1 Description of Application
The yellow Stripcoat had a paint-like consistency and was
provided in a five-gallon bucket ready to apply without
further preparation. Prior to the application of Stripcoat, a
Graco NovaTM 390 sprayer with a Graco 519 tip was primed
with the wet Stripcoat as directed by the manufacturer's
instructions. The sprayer was provided by Bartlett Services.
Inc. for this evaluation. Any commercially available, airless
paint sprayer with similar specifications could be used. The
sprayer manufacturer's operating instructions should be
followed.
Thereafter, Stripcoat was applied to the surfaces. There was
no calibrated pressure indicator. The maximum pressure of
this sprayer was 3,300 pounds per square inch (psi) and the
spray pattern that produced an even, covering coating with no
significant runs occurred when the pressure was adjusted to
the maximum and then the knob turned back approximately
one-quarter of a turn.
The Stripcoat was applied in a single coat with the objective
of attaining a wet thickness of 40 mils. Because coating
thickness was not measured, a qualitative guideline was
followed. The coating was applied thick enough to cover
the surface, but not so thick that the coating ran down the
wall. Spray application to the horizontal and vertical surfaces
took approximately five minutes. An average of 0.9 L of wet
Stripcoat was applied with each application to the surfaces
which has an area of 1.1 m2. Figure 5-1 shows a picture of
Stripcoat freshly applied to the vertical surface and, then
again, following the overnight drying time.
During the third Stripcoat application of the 7-day test, the
sprayer pump plugged and had to be re-primed before the
application could be successfully completed. Other than that
instance, the 7-day test application was completed without
-------
Table 5-3. Decontamination Efficacy With Each Application of Stripcoat
Test Stripcoat
Application
7-Day
30-Day
Pre-decon
#1
#2
#3
Pre-decon
#1
#2
#3
Pre-decon
#1
#2
#3
Pre-decon
#1
#2
#3
Pre-decon
#1
#2
#3
Activity
|jCi /Coupon
59.2
53.2
51.5
49.4
59.9
45.5
39.50
36.60
58.2
47.0
44.6
37.7
56.3
41.0
34.5
26.3
54.6
37.4
33.1
28.3
Total %R
NAa
10.1
13.0
16.6
NA
24.0
34.1
38.9
NA
19.2
23.4
35.2
NA
27.2
38.7
53.3
NA
31.5
39.4
48.2
%R Each
Application
NA
10.1
2.9
3.5
NA
24.0
10.0
4.8
NA
19.2
4.1
11.9
NA
27.2
11.5
14.6
NA
31.5
7.9
8.8
% of Total Removal
NA
61.2%
17.3%
21.4%
NA
61.8%
25.8%
12.4%
NA
54.6%
11.7%
33.7%
NA
51.0%
21.7%
27.3%
NA
65.4%
16.3%
18.3%
difficulty. Prior to the 7-day test, the paint sprayer pump, gun.
and hoses were new. Following the 7-day application, the
hoses and pump were rinsed with water as recommended by
Bartlett Services, Inc. and the five-gallon bucket containing
the Stripcoat was sealed. These items were stored in the
laboratory.
Between the 7-day and 30-day applications, two problems
emerged. First, on the day the 30-day tests were to begin.
the technicians removed the lid of the bucket to find that
the Stripcoat had solidified. This was unexpected because
conditions in the laboratory had not changed significantly
during the elapsed time. The paint apparently solidified
because the bucket had not been properly sealed when the
lid was placed back on for storage. Bartlett Services, Inc.
provided additional Stripcoat to complete the test.
When the additional Stripcoat arrived, the technicians began
priming the sprayer pump as had been done for the 7-day
application. First, the pump was primed with water to ensure
function of the pump and sprayer and then the pump was
primed with Stripcoat. When the fresh Stripcoat came into
contact with the pump and tubing, the pump bypass valve and
filter body became plugged with residue apparently left over
from the previous use. Apparently, the pump had not been
adequately cleaned after the last application of the 7-day test.
The pump had to be disassembled and then rinsed thoroughly
with water before the coating could be sprayed.
Following the first coating removal of the 30-day test, the
sprayer equipment was rinsed with water and the second
application was completed. During the third application.
the sprayer and tubing again clogged as they had during
the third application of the 7-day test. The pump was again
disassembled and rinsed with water before it would function
properly. Following these occurrences, Bartlett Services, Inc.
informed the technicians that a water rinse, as the company
-------
Figure 5-1. Stripcoat After Application (left) and After Drying Overnight (right)
f
had originally suggested, was not adequate for cleaning the
pump and tubing. A mineral spirits wash was necessary to
remove the residue from the walls of the pump and tubing.
Clearly, not doing this wash resulted in the plugging of the
pump and tubing and led to delays in coating application.
5.2.2 Description of Removal
The removal of Stripcoat was done following the overnight
drying which cured Stripcoat into a solid coating that, upon
removal, was elastic. After scoring the Stripcoat at the edge
of a coupon, the coating could, for the most part, be pulled
in large pieces off the surface across the border of coupons.
The first application of the 30-day test was somewhat
thinner than the other applications, so the Stripcoat tore
at the borders of the coupons. However, for the other five
applications, the coating was thick enough so that the cured
coating could be easily removed across the borders of the
coupons which had, at times, rather jagged edges. Figure 5-2
shows the removal process.
The dried coating removed from the surface was collected
in a tared bag and weighed. For the six removal cycles, the
Figure 5-2. Stripcoat Removal
•
average weight of dried coating was 276 g ± 42.5 g. The
time to remove Stripcoat from the two surfaces totaling
1.1 m2 ranged from 10-24 minutes for an average rate of
removal of 4.9 m2/hour.
5.2.3 Miscellaneous Operational Information and Data
Table 5-4 includes important operational parameters such
as the time required to apply and remove the coating,
required skill level of the operator, the portability of the
technology, estimated cost, required utilities, and cross
contamination concerns. All of the operational information
gathered during this evaluation was obtained from use of
Stripcoat on relatively small surfaces. (1.1 m2) that were built
with concrete coupons. Therefore some of the information
given in Table 5-4 could differ if Stripcoat was applied to
a larger surface or a surface that was more smooth or more
rough and jagged.
Data describing the rate of decontamination is given in
Table 5-4. Assuming that users of Stripcoat will be using
paint sprayers that had been cleaned with mineral spirits prior
to its application, the average rate of application of Stripcoat
-------
probably will not be the limiting rate step because use of
a paint sprayer is generally efficient. However, a thorough
paint sprayer cleaning between uses is critical given the
experiences described in Section 5.2.1. Application using a
paint sprayer will allow use on a wide variety of surfaces.
even irregularly shaped surfaces. Stripcoat was well-
suited to the irregular surfaces used during this evaluation.
Horizontal gaps of several millimeters existed between some
of the concrete coupons and the Stripcoat was removed
across those boundaries. Also, some of the coupons were of
slightly different heights and the Stripcoat was able to be
removed across those boundaries.
Cross-contamination of radionuclide during application
and removal of Stripcoat is an operational aspect that was
considered to a minimal extent during this evaluation.
As has been described, six coupons from each surface
had been contaminated prior to the construction of the
surfaces. The other coupons had not been contaminated
and upon placement into the test stand indicated extremely
low background levels of activity when measured with a
qualitative gamma counter. When all of the coupons were
removed from the test stand following the three application
and removal cycles of Stripcoat for both the 7-day and 30-
day tests, the non-contaminated coupons indicated an activity
level (again using the qualitative gamma counter) that was
higher than background.
While the study of cross-contamination was not a focus of the
evaluation, the activity from a few of the non-contaminated
coupons was quantitatively measured. Of the coupons that
were selected for measurement, the coupon that was located
just to the right of the "VA" coupon and below the "VET
coupon during the 7-day test had an activity of 0.86 uCi.
approximately 1.6% of the amount applied to any one of the
six contaminated coupons within each surface. However, the
Table 5-4. Operational Factors Gathered from the Evaluation
Parameter
Factors affecting
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; 20 minutes to prime pump
Application: Approximately 5 minutes and average of 0.78 L for 1.1 m2
Drying time: overnight
Removal time: 4.9 m2/hour
Application to more irregular surfaces than those encountered during this evaluation would not seem
to be much of a problem because a sprayer is able to reach most types of surfaces. Stripcoat cures
into an elastic coating that could be used on the surfaces made from concrete coupons used during
this evaluation. In most cases, Stripcoat could be removed across the borders of coupons even when
separated by several millimeters horizontally or vertically.
After a brief training session and time to acclimate to using a paint sprayer, most able-bodied people
could successfully perform both the application and removal procedures.
A paint sprayer generally requires 110 volt power. However, Stripcoat can also be applied with a roller or
brush, eliminating the need for a separate power source.
With the exception of extreme cold, which would prevent the application of Stripcoat (which is water-
based), its portability seems limitless.
Shelf life is advertised as one year, but a five-gallon bucket of Stripcoat solidified between the 7-day and
30-day tests. The paint apparently solidified because the bucket had not been properly sealed when the
lid was placed back on for storage.
Solid waste production: -0.26 kg/m2
Solid waste density: -0.145 g/cm3
Cured Stripcoat is extremely elastic. Each coating removal resulted in approximately 2 L of waste
material. Thorough mineral spirit cleaning of paint sprayer is required between uses or the sprayer will
likely clog.
No damage was visible to the eye; some loose particles could be seen to be stuck to the coating.
$23.50/L corresponding to $16.66/m2 for one application; Bartlett Services, Inc. suggests three
applications so that would correspond to $50.00/m2; that does not include the cost of a paint sprayer.
-------
rest of the coupons that were measured quantitatively had not specific to that location within the surfaces. As cross-
much lower activities. Over the 7-day and 30-day tests, the contamination was not a focus of the evaluation, the
residual activity of nine other non-contaminated coupons proper controls were not in place to thoroughly investigate
ranged from 0.0018 uCi - 0.05 uCi and had an average the observed cross-contamination. The possibility exists
activity of 0.015uCi ± 0.014 uCi. These coupons included that cross-contamination occurred during the construction
the coupon in the same position (during the 30-day test) as of the surfaces on the test stand and might be independent
the 0.86 uCi coupon mentioned above. This coupon had of the Stripcoat.
an activity of 0.0097 uCi, 0.0018% of the contaminated
coupons. The widely varying activity on a coupon in the
same position suggested that the cross-contamination was
-------
-------
6.0
Performance Summary
Summary results from evaluation of Stripcoat are presented
below for each performance parameter evaluated. Discussion
of the observed performance can be found in Section 5 of
this report.
6.1 Decontamination Efficacy
The decontamination efficacy attained by Stripcoat was
evaluated on separate test stands after both 7 days and 30
days following the contamination of the coupons. Overall.
Stripcoat decontaminated the concrete coupons with an
average %R of 32.0 ± 9.9. The %Rs from the vertical and
horizontal surfaces were determined to be not significantly
different from one another. In addition, the %Rs between the
7-day and 30- day tests and between coupons placed on the
edge and within the other coupons were also determined to
be not significantly different from one another. Upon
successive Stripcoat application and removal cycles, 51%
- 65% of the Cs-137 removed in total during all three
application cycles occurred during the first application cycle.
6.2 Deployment and Operational Factors
Stripcoat is supplied as a ready for use coating with a
consistency similar to wall paint. Stripcoat was applied.
following manufacturer's recommendation, to the surfaces
with an airless paint sprayer. The horizontal and vertical
surfaces used during this evaluation totaled l.lm2 and each
complete application took approximately 5 minutes. The
objective of application was to attain a layer of paint-like
coating approximately 40 mils thick. However, because a
measurement of coating thickness was not performed, a
qualitative guideline was followed. The coating was applied
to a thickness that was enough to cover the surface by visual
inspection, but not too thick that the coating ran down the
wall. Following application, the coating was allowed to dry
overnight and then removed using a paint scraper to score
the edge of the coupons . The coating was pulled from the
surface. In most cases, Stripcoat was removed in large
pieces across the borders between coupons. The Stripcoat
removal rate was 4.9 m2 per hour, the rate of waste generation
(removed coating) was 0.26 kg/m2, and the volume of the
waste was, on average, 0.145 g/cm3. In addition, Stripcoat
was well suited for rough or jagged surfaces because the
cured coating was easily removed across the borders of
coupons (a distance of approximately 0.3-0.7 cm) which
created an irregular surface. A limited evaluation of cross-
contamination was performed, and the results confirmed that
cross-contamination did occur. Any damage to the surface
of the concrete caused by Stripcoat was not visible to the
naked eye.
6.3 Conclusion
Stripcoat removed approximately 32% of the Cs-137
from the unpainted concrete coupons placed together to
form concrete surfaces with both horizontal and vertical
orientations. Stripcoat worked the same in either
orientation and after 7 and 30 days following the application
of Cs-137 to the concrete coupons. Stripcoat could be
applied to irregular surfaces. The coating was elastic and
easily removed across the border of the coupons.
-------
-------
1. Test/QA Plan, The Performance of Selected Radiological Decontamination
Processes on Urban Substrates, Version 1.0, Battelle, Columbus, OH, Sept. 2007
2. Quality Management Plan for the Technology Testing and Evaluation Program.
Version 2.0, Battelle, Columbus, Ohio, January 2006.
3. ASTM Standard C 150-07, 2007, "Standard Specification for Portland Cement,"
ASTM International, West Conshohocken, PA, www.astm.org.
4. 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, classified program.
5. 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).
7.0
References
-------
&EPA
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGES FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development
National Homeland Security Research Center
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
Recycled/Recyclable
Printed with vegetable-based ink on
paper that contains a minimum of
50% post-consumer fiber content
processed chlorine free
------- |