EPA 600/R-11/083 | August 2011 | www.epa.gov/ord
United States
Environmental Protection
Agency
Technology Evaluation Report
Environmental Alternatives, Inc
Rad-Release I and II for
Radiological Decontamination
Office of Research and Development
National Homeland Security Research Center
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Disclaimer
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development's National Homeland Security Research Center, funded and managed this
technology evaluation through 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.
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 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
National Homeland Security Research Center (NHSRC) 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 NHSRC's research is to develop and deliver information on
decontamination methods and technologies to clean up CBR contamination. When
directing such a recovery operation, EPA and other stakeholders must identify and
implement decontamination technologies that are appropriate for the given situation. 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. Through TTEP, NHSRC 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.
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, Director
National Homeland Security Research Center
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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
Emily Snyder
Sang Don Lee
Eletha Brady-Roberts
Scott Hudson
Alyssa Hughes
University of Tennessee
Dr. Howard Hall
United States Department of Energy's Idaho National Laboratories
Battelle Memorial Institute
in
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Contents
Disclaimer i
Foreword ii
Acknowledgments iii
Abbreviations/Acronyms vii
Executive Summary viii
1.0 Introduction 1
2.0 Technology Description 3
3.0 Experimental Details 5
3.1 Experiment Preparation 5
3.1.1 Concrete Coupons 5
3.1.2 Coupon Contamination 6
3.1.3 Measurement of Activity on Coupon Surface 7
3.1.4 Surface Construction Using Test Stand 7
3.2 Evaluation Procedures 8
4.0 Quality Assurance/Quality Control 10
4.1 Intrinsic Germanium Detector 10
4.2 Audits 11
4.2.1 Performance Evaluation Audit 11
4.2.2 Technical Systems Audit 11
4.2.3 Data Quality Audit 12
4.3 QA/QC Reporting 12
5.0 Evaluation Results 13
5.1 Decontamination Efficacy 13
5.2 Deployment and Operational Factors 15
6.0 Performance Summary 18
6.1 Decontamination Efficacy 18
6.2 Deployment and Operational Factors 18
7.0 References 19
IV
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Figures
Figure 2-1. Rad-Release container (right) and spray bottle applicator (left) 4
Figure 3-1. Demonstration of contaminant application technique 6
Figure 3-2. Containment tent: outer view (left) and inner view with test stand
containing contaminated coupons (right) 7
Figure 5-1. Rinsing and vacuuming Rad-Release from concrete coupon 16
Tables
Table 3-1. Characteristics of Portland Cement Clinker Used to Make Concrete
Coupons 5
Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies 10
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check 11
Table 5-1. Decontamination Efficacy Results for Rad-Release I 14
Table 5-2. Decontamination Efficacy Results for Rad-Release II 14
Table 5-3. Operational Factors Gathered from the Evaluation 17
v
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Abbreviations/Acronyms
ANSI
ASTM
BQ
CBRNIAC
°C
cc
CFR
Cs
cm
cm2
DARPA
DF
DHS
DOD
EAI
EPA
Eu
°F
IEEE
INL
keV
mL
L
m
m2
(iCi
NHSRC
NIST
ORD
PE
PPE
%R
QA
QC
QMP
ROD
RH
RML
RSD
TCLP
Th
TSA
TTEP
American National Standards Institute
ASTM International
Becquerel
Chemical, Biological, Radiological, Nuclear Defense Information Analysis
Center
degrees Celsius
cross-contamination
Code of Federal Regulations
cesium
centimeter
square centimeter
Defense Advanced Research Projects Agency
decontamination factor
U.S. Department of Homeland Security
Department of Defense
Environmental Alternatives, Inc.
U.S. Environmental Protection Agency
Europium
degrees Fahrenheit
Institute of Electrical and Electronics Engineers
Idaho National Laboratory
kilo electron volts
milliliter(s)
liter
meter
square meter
microCurie
National Homeland Security Research Center
National Institute of Standards and Technology
Office of Research and Development
performance evaluation
personal protective equipment
percent removal
quality assurance
quality control
quality management plan
radiological dispersion device
relative humidity
Radiological Measurement Laboratory
relative standard deviation
Toxicity Characteristic Leaching Procedure
thorium
technical systems audit
Technology Testing and Evaluation Program
VI
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Executive Summary
The U.S. Environmental Protection Agency's (EPA) National Homeland Security
Research Center (NHSRC) 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), NHSRC evaluated the Environmental Alternatives Inc. (EAI) Rad-
Release I and Rad-Release II and their ability to remove radioactive cesium (Cs)-137
from the surface of unpainted concrete.
Experimental Procedures. The Rad-Release I decontamination technology is a
chemical process that involves the topical application of a single decontamination
solution to treat various substrates bearing radiological contamination. Rad-Release II is
a similar chemical process that involves the topical application of two solutions. Eight 15
centimeter (cm) x 15 cm unpainted concrete coupons were contaminated with
approximately 1 microCurie (|iCi) of Cs-137 per coupon. The amount of contamination
deposited on each coupon was measured using gamma spectroscopy. The eight
contaminated coupons were placed in a test stand (along with one uncontaminated blank
coupon) that was designed to hold nine concrete coupons in a vertical orientation to
simulate the wall of a building. Four coupons were decontaminated with Rad-Release I
and four with Rad-Release II. The one-step Rad-Release I included application of a
spray, a 30 minute dwell time, rinse, and removal. Rad-Release II included two
formulations which followed the same procedure as Rad-Release I. The decontamination
efficacy was determined by calculating both a decontamination factor (DF) and percent
removal (%R). Important deployment and operational factors were also documented and
reported.
Results. The decontamination efficacy (in terms of %R) attained for Rad-Release I and
Rad-Release II was evaluated for each concrete coupon used during the evaluation. When
the decontamination efficacy metrics (%R and DF) of the four contaminated coupons
decontaminated by each were averaged together, the average %R for Rad-Release I was
71% + 13% and the average DF was 3.9 + 1.5. The average %R for Rad-Release II was
85% + 2% and the average DF was 7.0+1.1.
The application of Rad-Release I and Rad-Release II was performed using plastic spray
bottles. For Rad-Release I, the concrete coupons were thoroughly wetted with Rad-
Release I with 3-4 sprays. Then, the solution was worked into the surface of the coupon
by scrubbing the entire surface of the coupon once with a scouring pad. During this
evaluation, the initial application of Rad-Release I took only 10-15 seconds for each
coupon. The next step was a 30 minute dwell time for the Rad-Release I to reside on the
surfaces of the concrete coupons. After 30 minutes, the surface of the concrete coupons
were thoroughly wetted with a deionized water/10% nitric acid rinse solution using
another spray bottle and then the sprayed material was removed with a wet vacuum
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(vacuuming took about one minute per coupon). Rad-Release II was used in the same
way but there were two formulations that went through the process described above.
Therefore, the Rad-Release I application took approximately 37 minutes and the Rad-
Release II application took approximately 65 minutes because the dwell times were the
major factor in the application time.
The waste generated through use of Rad-Release I and Rad-Release II was estimated to
be approximately 7 liters (L)/ square meter (m2). As used for this evaluation, only the
wet vacuum required electricity. Scaled up applications in remote locations may require
additional utilities to provide means for sprayer or foamer application and vacuum
removal. Minimal training would be required for technicians using Rad-Release I and
Rad-Release II, and the surface of the concrete was not visibly damaged during use.
Vlll
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1.0 Introduction
The U.S. Environmental Protection
Agency's (EPA) National Homeland
Security Research Center (NHSRC) is
helping to protect human health and the
environment from adverse effects
resulting from acts of terror. NHSRC is
emphasizing decontamination and
consequence management, water
infrastructure protection, and threat and
consequence assessment. In doing so,
NHRSC is working to develop tools and
information that will improve the ability
of operational personnel to detect the
intentional introduction of chemical,
biological, or radiological contaminants
on or into buildings or water systems, to
contain or mitigate these contaminants,
to decontaminate affected buildings
and/or water systems, and to dispose of
contaminated materials resulting from
clean-ups.
NHSRC's Technology Testing and
Evaluation Program (TTEP) works in
partnership with recognized testing
organizations; stakeholder groups
consisting of buyers, vendor
organizations, and permitters; and
through the participation of individual
technology developers in carrying out
performance tests on homeland security
technologies. The program evaluates the
performance of 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. Through TTEP, NHSRC
provides high-quality information that is
useful to decision makers in purchasing
or applying the evaluated technologies,
and in planning cleanup operations. The
evaluations generated through TTEP
provide 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, NHSRC evaluated the
performance of two technologies from
Environmental Alternatives, Inc. (EAI)
(Keene, NH), Rad-Release I and Rad-
Release II, in removing radioactive
isotope cesium (Cs)-137 from unpainted
concrete. A peer-reviewed test/QA plan
was followed, entitled "The Performance
of Selected Radiological
Decontamination Processes on Urban
Substrates", Version 1.0, Amendment 1
dated July 14, 2010. This document will
be referred to as the test/QA plan and
was developed according to the
requirements of the Quality Management
Plan (QMP) for the Technology Testing
and Evaluation Program, Version 3.0
dated January 2008. The evaluation
generated the following performance
information:
• Decontamination efficacy,
defined as the extent of
radionuclide removal following
use of Rad-Release I and Rad-
Release II, and the possibility of
cross-contamination (CC)
1
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• Deployment and operational
factors, including the
approximate rate of surface area
decontamination, applicability to
irregular surfaces, skilled labor
requirement, utility requirements,
portability, secondary waste
management, and technology
cost.
The evaluation of Rad-Release I and
Rad-Release II took place October 27,
2010, with the pre-evaluation activity
measurements occurring in September
2010 and the post-evaluation activity
measurements occurring in early
November 2010. All of the experimental
work took place in a radiological
contamination area at the U.S.
Department of Energy's Idaho National
Laboratory (INL). This report describes
the quantitative results and qualitative
observations gathered during the
evaluation of the Rad-Release I and Rad-
Release II. The contractor and EPA
were responsible for QA oversight. A
technical systems audit (TSA) was
conducted during the evaluation as well
as a data quality audit of the evaluation
data.
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2.0 Technology Description
This technology evaluation report
provides results on the performance of
Rad-Release I and Rad-Release II under
laboratory conditions. The following
description of Rad-Release I and Rad-
Release II is based on information
provided by the vendor and was not
verified during this evaluation.
The Rad-Release I decontamination
technology is a chemical process that
involves the topical application of a
single decontamination solution to treat
various substrates bearing radiological
contamination. Rad-Release II is a
similar chemical process that involves
the sequential topical application of two
solutions (applied in the order directed
by EAI). Both Rad-Release
technologies extract radionuclides,
including transuranics, from nearly all
substrates. This process was developed
to be used in sequence to synergistically
remove the contaminants via the
migration pathways, pores and
capillaries of the contaminated material.
Rad-Release I and II are effective for
both loose surface and fixed subsurface
contamination and situations in which
the contamination is a mixture of pure
elements, oxides, and related compounds
with varying solubility indices.
Substrates for which Rad-Release I and
II can be used include those that are both
porous and seemingly nonporous. Both
technologies can be deployed on various
geometries including walls, ceilings,
equipment, structural beams, internal
piping and highly irregular surfaces.
To maximize the efficacy of the
extraction process, the chemistry and
application are tailored to the specific
substrate, targeted contaminant(s), and
surface interferences. The Rad-Release I
solution contains salts to promote ion
exchange and surfactants to remove dirt,
oil, grease, and other surface
interferences. Broad-target and target-
specific chelants are blended into the
solution to sequester and encapsulate the
contaminants, keeping them in
suspension until they are removed by the
subsequent rinse. Rad-Release II
includes one solution that is chemically
similar to Rad-Release I and serves the
same purpose in decontamination
(although it is not the same solution).
Rad-Release II includes a second
solution designed as a caustic solution
containing salts to promote ion
exchange, ionic and nonionic
surfactants, and additional sequestering
agents, also utilized to encapsulate the
contaminants and keep them in
suspension until they are removed by the
subsequent rinse.
Both Rad-Release I and Rad-Release II
are applied in low volumes, as either an
atomized spray or foam. Foam
deployment of the solution is most
appropriate for large scale applications
while the spray application (as used
during this evaluation) is beneficial for
smaller applications and applications
where waste minimization is a critical
factor. After the decontamination
solution is applied, light mechanical
action (e.g., a light scrubbing or
brushing with a scouring pad) is applied
to ensure good contact with the
contaminated surface. The solution is
then left to reside for 30 minutes
followed by a rinse and removal.
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Several options are available to facilitate
the removal step (e.g., vacuuming,
simple wiping with absorbent laboratory
wipes or rags for small surfaces, use of a
clay overlay technique to wick out the
Rad-Release and contamination over
time and then remove the clay at a later
date, or use of an absorbent polymer that
is sprayed over the chemically treated
surface to leach or wick out the
contaminant laden solutions and bind
them up). The sequence of application,
dwell, rinse, and removal of the
decontamination solution constitutes a
single iteration. This procedure may be
repeated, as needed, until the desired
residual contaminant levels are achieved.
The blended solution contains no
hazardous components regarding
flammability or reactivity (as per Title
40 of the Code of Federal Regulations
Section 261 (40CFR 261)) and has no
components that would be classified as
hazardous for disposal under Toxicity
Characteristic Leaching Procedure
(TCLP) testing. As a result, the waste
stream from a project can be
characterized based on the contaminants
that were removed. Liquid waste
volumes are usually 400 mL/square
meter (m2) to 4000 mL/m2 of
contaminated substrate. Depending on
the matrix and the amount of rinse
applied, the liquid waste stream may
have a resultant pH of less than 2. A pH
neutral waste can be attained by
stoichiometrically adding sodium
bicarbonate or another neutralizing
agent. Waste may be handled by
solidification, incineration, discharged to
liquid effluent treatment systems, and/or
evaporation. More information is
available at www.eai-inc.com.
Figure 2-1. Rad-Release container (right) and spray bottle applicator (left).
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3.0 Experimental Details
3.1 Experiment Preparation
3.1.1 Concrete Coupons
The concrete coupons were prepared
from a single batch of concrete made
from Type II Portland cement. The
ready-mix company (Burns Brothers
Redi-Mix, Idaho Falls, ID) that supplied
the concrete for this evaluation provided
the data which describe the cement
clinker used in the concrete mix. For
Type II Portland cement, the ASTM
International (ASTM) Standard C 150-71
specifies that tricalcium aluminate
accounts for less than 8% of the overall
cement clinker (by weight). The cement
clinker used for the concrete coupons
was 4.5% tricalcium aluminate (Table 3-
1). For Type I Portland cement the
tricalcium aluminate content should be
less than 15%. Because Type I and II
Portland cements differ only in
tricalcium aluminate content, the cement
used during this evaluation meets the
specifications for both Type I and II
Portland cements. The apparent porosity
of the concrete from the prepared
coupons ranged from 15-30%.
Table 3-1. Characteristics of Portland Cement Clinker
Used to Make Concrete Coupons
Cement Constituent
Percent of Mixture
Tricalcium Silicate
Dicalcium Silicate
Tricalcium Aluminate
Tetracalcium Aluminoferrite
Minor Constituents
57.6
21.1
4.5
8.7
8.1
The concrete was representative of
exterior concrete commonly found in
urban environments in the United States
as shown by INL under a previous
project entitled, "Radionuclide Detection
and Decontamination Program. Broad
Agency Announcement 03-013"
sponsored by the U.S. Department of
Defense (DOD), Defense Advanced
Research Projects Agency (DARPA) and
U.S. Department of Homeland Security
(DHS). The wet concrete was poured
into 0.9 meter (m) square plywood forms
with the exposed surface "floated" to
allow the smaller aggregate and cement
paste to float to the top, and the concrete
was 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 x 15 cm
square, and had a surface finish that was
consistent across all the coupons. No
further weathering, conditioning, or
treatment was performed on these
concrete coupons.
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3.1.2 Coupon Contamination
Eight coupons were contaminated by
spiking individually with 2.5 milliliters
(mL) of aqueous solution that contained
0.4 microCurie (|iCi)/mL Cs-137 as a
solution of cesium chloride,
corresponding to an activity level of
approximately 1 jiCi over the 225 square
centimeters (cm2) surface. Application
of the Cs-137 in an aqueous solution was
justified because even if Cs-137 were
dispersed in a particle form following a
radiological dispersion device (RDD) or
"dirty bomb" event, morning dew or
rainfall would likely occur before the
surfaces could be decontaminated. In
addition, from an experimental
standpoint, it is much easier to apply
liquids, rather than particles,
homogeneously across the surface of the
concrete coupons. The liquid spike was
delivered to each coupon using an
aerosolization technique developed by
INL (under a DARPA/DHS project).
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 liter (L) per minute
created a turbulent flow through the first
syringe. When the contaminant solution
in the second syringe was introduced, it
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 surfaces of the
coupons. The photographs in Figure 3-1
show this procedure being performed
using a nonradioactive, nonhazardous
aqueous dye to demonstrate that the 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 concrete coupon was measured to
quantify contamination levels both
before and after evaluation of Rad-
Release I and Rad-Release II. 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 Cs-137
from the surface stabilized to a relative
standard deviation (RSD) of less than
2%. Gamma-ray spectra acquired from
Cs-137 contaminated coupons were
analyzed using INL Radiological
Measurement Laboratory (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 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), a stainless steel test
stand that held three rows of three
concrete coupons was used. The test
stand, approximately 2.7 m x 2.7 m, was
erected within a containment tent. The
concrete coupons were placed into
holders so their surfaces extended just
beyond the surface of the stainless steel
face of the test stand. Eight of the nine
coupons placed in the test stand were
contaminated with Cs-137, which has a
half-life of 30 years. One
uncontaminated coupon was placed in
the bottom row of the test stand (position
8) and decontaminated in the same way
as the other coupons. This coupon,
referred to as the CC blank, was placed
there to observe possible CC caused by
the decontamination higher on the wall.
Figure 3-2 shows the containment tent
and the test stand loaded with the
concrete coupons.
Figure 3-2. Containment tent: outer view (left) and inner view with test stand
containing contaminated coupons with numbered coupon positions (right).
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3.2 Evaluation Procedures
The nine concrete coupons in the test
stand which had been contaminated
approximately one month before were
decontaminated using Rad-Release I and
Rad-Release II. Rad-Release I was
applied to the coupons in positions 3, 5,
6, 8 (blank coupon), and 9 while Rad-
Release II was used on the coupons in
positions 1, 2, 4, and 7. Both Rad-
Release I and Rad-Release II were
applied in the order given above to
simulate an approach that would likely
be taken in an actual decontamination
event, where higher wall surfaces would
be decontaminated first because of the
possibility of secondary contamination
lower on the wall.
The application of Rad-Release I and
Rad-Release II was performed using
plastic spray bottles (32 oz. Heavy Duty
Spray Bottle, Rubbermaid Professional,
Atlanta, GA). For Rad-Release I, the
concrete coupons were thoroughly
wetted with Rad-Release I with 3-4
sprays. Then, the solution was worked
into the surface of the coupon by
scrubbing the entire surface of the
coupon once with a scouring pad (Heavy
Duty Scouring Pad, 3M Scotch-Brite, St.
Paul, MN). During this evaluation, the
initial application of Rad-Release I took
only 10-15 seconds for each coupon.
The next step was a 30 minute dwell
time for the Rad-Release I to reside on
the surfaces of the concrete coupons.
The coupon surfaces were kept damp
with 1-2 sprays of additional Rad-
Release I approximately every five
minutes. The additional 1-2 sprays of
the Rad-Release solutions was
performed to simulate foam collapse, i.e.
the reintroduction of fresh Rad-Release
solutions to the contaminated matrix, as
would be observed when deployed as a
foam for larger scale real-world
applications. After 30 minutes, the
surface of the concrete coupons were
thoroughly wetted with a deionized
water/10% nitric acid rinse solution
using another spray bottle and then the
solution sprayed on the surface was
removed with a wet vacuum (12 gallon,
4.5 horsepower, QSP® Quiet Deluxe,
Shop-Vac Corporation, Williamsport,
VA) which took about one minute per
coupon. The overall decontamination
method for Rad-Release I included:
1. Apply Rad-Release I with spray
bottle
2. Scrub surface with scouring pad
3. Wait 30 minutes, during which
the surface is kept wet with
additional sprays every 5 minutes
(to simulate foam collapse)
4. Thoroughly wet with deionized
water/10% nitric acid rinse
solution
5. Remove with wet vacuum by
moving over the surface one time
with the open end of a 1 Vi inch
hose flat against the surface
without an attachment.
The application of Rad-Release II was a
two-step application done using the
same steps as described above for Rad-
Release I. The above procedure was
followed for Rad-Release II, Solution 1.
Then, the same procedure was repeated
for Rad-Release II, Solution 2.
Therefore, the Rad-Release I procedure
took approximately 37 minutes to
complete while the Rad-Release II
procedure took approximately 65
minutes.
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The temperature and relative humidity end and the RH was 20% in both
(RH) were recorded at the start and instances. According to the vendor,
finish. The temperature was 21 °C (70 these conditions were acceptable for use
°F) at the start and 19 °C (66 °F) at the of the Rad-Release solutions.
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4.0 Quality Assurance/Quality Control
QA/QC procedures were performed in
accordance with the program 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)2. 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 late September and the
post-contamination results were
measured in late November. 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 from Th-228 Calibration Energies
Calibration Energy Levels (keV)
Date Range Energy 1 Energy 2 Energy 3 Energy 4 Energy 5
(2010) 238.632 583.191 860.564 1620.735 2614.533
9-27 to 11-2
10-5 to 11-8
10-12 to 11-16
10-19 to 11-24
-0.003
-0.003
-0.004
-0.005
0.010
0.011
0.015
0.014
-0.039
-0.029
-0.040
-0.001
-0.121
-0.206
-0.245
-0.320
0.017
0.023
0.031
0.043
Gamma ray counting was continued on
each coupon until the activity level of
Cs-137 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 comprises 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 an
expert 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
four arbitrarily selected coupons from
the stock of concrete coupons used for
10
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this evaluation. The ambient activity
level of these coupons was measured for
at least two hours. No activity was
detected above the minimum detectable
level of 2xlO"4 jiCi on these coupons.
Because the background activity was not
detectable (and the detectable level was
more than 2,500 times lower than the
post-decontamination activity levels), no
background subtraction was required.
Throughout the evaluation, a second
measurement was taken on five coupons
in order to provide duplicate
measurements to evaluate the
repeatability of the instrument. Three of
the duplicate measurements were
performed after contamination prior to
application of the decontamination
technology and two were performed
after decontamination. All five of the
duplicate pairs showed difference in
activity levels of 2% or less, within the
acceptable difference of 5%.
4.2 Audits
4.2.1 Performance Evaluation Audit
RML performed regular checks of the
accuracy of the Th-228 daughter
calibration standards (during the time
when the detector was in use) by
measuring the activity of a National
Institute of Standards and Technology
(NIST)-traceable europium (Eu)-152
standard (in units of Becquerel, BQ) and
comparing it to the accepted NIST value.
Results within 7% of the NIST value are
considered (according to RML internal
quality control procedures) to be within
acceptable limits. The Eu-152 activity
comparison is a routine QC activity
performed by INL, but for the purposes
of this evaluation serves as the
performance evaluation (PE) audit. This
audit confirms the accuracy of the
calibration of the germanium detector
critical to the results of the evaluation.
Table 4-2 gives the results of each of the
audits applicable to the duration of the
evaluation including the pre-
decontamination measurements
performed in late September. All results
are below the acceptable difference of
7%.
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check
NIST Activity INL RML Relative Percent
Date (BQ) Result (BQ) Difference
9-15-2010
10-13-2010
11-10-2010
124,600
124,600
124,600
122,000
123,100
121,600
2%
1%
2%
4.2.2 Technical Systems A udit
A TSA was conducted during testing at
INL to ensure that the evaluation was
performed in accordance with the
test/QAplan. As part of the audit, the
actual evaluation procedures were
compared with those specified in the
test/QA plan and 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
Contractor QA Manager.
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4.2.3 Data Quality Audit
At least 10% of the raw data acquired
during the evaluation and transcribed
into spreadsheets for use in the final
report was verified by the QA manager.
The data were traced from the initial raw
data collection, through reduction and
statistical analysis, to final reporting, to
ensure the integrity of the reported
results.
4.3 QA/QC Reporting
Each assessment and audit was
documented in accordance with the
test/QA plan. Draft assessment reports
were prepared and sent to the Test
Coordinator and Program Manager for
review and approval. Final assessment
reports were then sent to the EPA QA
Manager and contractor staff.
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5.0 Evaluation Results
5.1 Decontamination Efficacy
The decontamination efficacy of the
Rad-Release I and Rad-Release II was
measured for each contaminated coupon
in terms of percent removal (%R) and
decontamination factor (DF). Both of
these parameters provide a means of
representing the extent of
decontamination accomplished by a
technology. The %R gives the extent as
a percent relative to the activity and the
DF is the ratio of the initial activity to
the final activity or the factor by which
the activity was decreased. These terms
are defined by the following equations:
%R = (l-Af/A0)x 100%
DF = Ao/Af
where, A0 is the radiological activity
from the surface of the coupon before
application of Rad-Release I and Rad-
Release II and Af is radiological activity
from the surface of the coupon after
treatment. While the DFs are reported,
the narrative describing the results
focuses on the %R.
Tables 5-1 and 5-2 give the %R and DF
for Rad-Release I and Rad-Release II,
respectively. All coupons were oriented
vertically. The target activity for each of
the contaminated coupons (pre-
decontamination) was within the
acceptable range of 1 jiCi + 0.5 jiCi. The
overall average (plus or minus one
standard deviation) of the contaminated
coupons was 1.11 jiCi + 0.041 jiCi and
1.0 jiCi + 0.08 jiCi for the coupons used
for Rad-Release I and Rad-Release II,
respectively. The post-decontamination
coupon activities were less than the pre-
decontamination activities showing an
overall reduction in activity for both
technologies. For Rad-Release I, the
%R averaged 71% + 13% and the DF
averaged 3.9+1.5. Overall, the %R
ranged from 53% to 82% and the DF
ranged from 2.1 to 5.5. For Rad-Release
II, the %R averaged 85 + 2% and the DF
averaged 7.0+1.1. Overall, the %R
ranged from 83% to 88% and the DF
ranged from 5.7 to 8.5. A t-test was
performed on the two data sets in order
to determine the likelihood of generating
the observed %R data if the data sets
were not different. The probability of
generating these data sets if the data sets
were not significantly different was
0.133 so at a 95% confidence interval,
the Rad-Release I and Rad-Release II
were not considered significantly
different from one another.
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Table 5-1. Decontamination Efficacy Results for Rad-Release I
Coupon
Location in Pre-Decon Activity Post-Decon Activity
Test Stand (uCi / Coupon) (uCi / Coupon) %R
DF
Top right
Center middle
Center right
Bottom right
Average
Std. Dev
1.08
1.17
1.09
1.10
1.11
0.041
0.51
0.36
0.20
0.23
0.32
0.14
53%
70%
82%
79%
71%
13%
2.1
3.3
5.5
4.8
3.9
1.5
Table 5-2. Decontamination Efficacy Results for Rad-Release II
Coupon
Location in Pre-Decon Activity Post-Decon Activity
Test Stand (uCi / Coupon) (uCi / Coupon) %R
DF
Top left
Top middle
Center left
Bottom left
Average
Std. Dev
0.97
1.04
1.12
0.96
1.0
0.08
0.14
0.12
0.20
0.14
0.15
0.03
85%
88%
83%
85%
85%
2%
6.9
8.5
5.7
6.8
7.0
1.1
As described in Section 3.1, the CC
blank was included in the test stand to
evaluate the potential for CC due to
application of Rad-Release I and Rad-
Release II on wall locations above the
placement of the uncontaminated
coupon. In the case of this evaluation,
Rad-Release I was applied to the
contaminated coupon in the center
middle position. Upon application of the
Rad-Release I to the contaminated center
middle coupon, some Rad-Release I ran
down the wall onto the uncontaminated
coupon in the bottom middle position.
Rad-Release I was then applied to the
CC blank using the same method as for
the other coupons. After
decontamination, the activity of the CC
blank was found to be 0.0218 jiCi. This
value was 10 times greater than the
minimum detectable level, but more than
5 times less than the post-
decontamination activities of the
contaminated coupons. Therefore, this
result suggested that cross-
contamination resulting from the
application of Rad-Release I and Rad-
Release II on coupons located above the
CC blank was detectable, but minimal.
Assuming that the Rad-Release I
attained a 71%R on the CC blank, this
residual activity of 0.0218 jiCi would
correspond to a pre-decontamination
activity of 0.1 jiCi, consistent with
approximately 10% of the activity from
the coupon located above. The liquid
nature of the decontamination solutions
facilitates flow of contamination down
the side of the test stand. However, it is
likely that Rad-Release I and Rad-
Release II would not flow as easily
down the side of an actual concrete wall
as was the case for the stainless steel test
stand, which would tend to reduce cross-
contamination.
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5.2 Deployment and Operational
Factors
A number of operational factors were
documented by the technician that
performed the testing with the Rad-
Release I and Rad-Release II. One of the
factors was the degree of difficulty in
application. The application of Rad-
Release I and Rad-Release II was
described in Section 3.2 and included
use of a plastic spray bottle. Application
of the Rad-Release I and Rad-Release II
solutions to each coupon took 10-15
seconds in addition to the recommended
dwell time of 30 minutes for each
solution. For Rad-Release I, there was
only one solution so there was only one
30 minute dwell time prior to rinsing by
spraying with the deionized water/10%
nitric acid solution and wet vacuum
removal (approximately 1 minute per
coupon). The total time elapsed for the
five coupons decontaminated with Rad-
Release I was approximately 37 minutes.
For Rad-Release II, there were two
solutions that were applied using the
identical procedure that included a 30
minute dwell time for each. The total
elapsed time for the four coupons
decontaminated with Rad-Release II was
approximately 65 minutes. These
application and removal times are
applicable only to the experimental
scenario including these rather small
concrete coupons. According to EAI, if
Rad-Release I and Rad-Release II were
applied to larger surfaces, larger
application tools such as larger sprayers
or foamers would likely be used which
would impact the application rate. In
addition, larger vacuum heads would be
used for removal.
Rad-Release I and Rad-Release II
behaved very similarly during
application and removal. Both the Rad-
Release I and Rad-Release II, Solution 1
reacted with the surface of the concrete
to create a thin foam of bubbles upon
application. EAI indicated that this was
likely a release of carbon dioxide due to
acid-base chemistry occurring at the
surface of the concrete. Neither Rad-
Release I nor Rad-Release II caused any
immediate visible damage to the surface
of the coupons, however long term
surface changes were not evaluated. The
Rad-Release II coupons did not dry as
quickly as the Rad-Release I coupons.
Following use of Rad-Release I, the
coupons could be removed from the test
stand almost immediately and be dry to
touch, while the Rad-Release II coupons
were left in the test stand overnight
before removing them from the test
stand and were still somewhat damp.
Figure 5-1 shows a photograph of the
rinse and vacuuming step of the Rad-
Release procedure. The personal
protective equipment (PPE) used by the
technician in the picture was required
because the work was performed in a
radiological contamination area using
Cs-137 on the concrete coupon surfaces.
Whenever radioactive contaminated
material is handled, anti-contamination
PPE will be required and any waste will
be considered low level radioactive
waste (and will need to be disposed of
accordingly). The required PPE was not
driven by the use of the Rad-Release
solutions (which are not hazardous),
rather the interaction with surfaces
contaminated with Cs-137.
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Figure 5-1. Rinsing and vacuuming Rad-Release from concrete coupon.
Table 5-3 summarizes qualitative and quantitative practical information gained by the
operator during the evaluation of Rad-Release I and Rad-Release II. All of the
operational information was gathered during use of Rad-Release I and Rad-Release II on
the concrete coupons inserted into the test stand. Some of the information given in Table
5-3 could differ if the Rad-Release I and Rad-Release II were applied to a larger surface
or to a surface that was smoother or more rough and jagged than the concrete coupons
used during this evaluation.
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Table 5-3. Operational Factors Gathered from the Evaluation
Parameter
Decontamination
rate
Applicability to
irregular surfaces
Skilled labor
requirement
Utilities
requirement
Extent of portability
Secondary waste
management
Surface damage
Cost (material)
Description/Information
Technology Preparation: Rad-Release I and Rad-Release II are provided ready to use.
The solutions were transferred into spray bottles and applied.
Application: The limiting factor of decontamination rate is the surface area covered
before the 30 minute dwell times. Larger surfaces would likely utilize sprayer or
foamer application. During this experimental design, the initial application to the
concrete coupons took only seconds and then the coupons were kept damp (to
simulate the ongoing presence of a foam during a large-scale application) with
reapplication during the dwell time. Rinsing and vacuuming took approximately one
minute per coupon. In all, the application and removal took seven minutes in
addition to the 30 minute dwell time for Rad-Release I (for a total elapsed time of 37
minutes) and five minutes in addition to the 60 minute wait time for Rad-Release II.
Aside from the wait times, this corresponds to a decontamination rate of
approximately 1 m2/hr for both Rad-Release I and II.
Estimated volumes used included 330 mL of Rad-Release I and Rad-Release II
Solution 1, 380 mL Rad-Release II Solution 2, and 440 mL of the rinse solution.
Application to irregular surfaces would not seem to be problematic as Rad-Release I
and Rad-Release II are sprayed into hard to reach locations. Removal may be
difficult if vacuuming jagged edges or gaps is required.
Adequate training would likely include a few minutes of orientation so the technician
is familiar with the application technique including dwell times and requirement of
keeping surface wet. Larger surfaces may require more complex equipment such as
spray or foam application.
Electricity for the wet vacuum.
At a scale similar to that used for this evaluation, vacuum removal would be the only
portability factor. However, for larger scale applications, limiting factors would
include the ability to apply the Rad-Release I and Rad-Release II at an adequate scale
and then rinse and remove with a vacuum. Portable electrical generation or vacuum
capability may be required.
1.5 L of liquid was applied to the concrete coupons used during this evaluation. That
volume corresponds to a waste generation rate of approximately 7 L/m2 depending on
how much of the solutions absorb to the surfaces. Because Cs-137 was used for this
testing, all waste (in vacuum) was solidified and disposed of as low level radioactive
waste.
Concrete surfaces appeared undamaged.
Rad-Release solutions are not sold as a stand-alone product. EAI, Inc. offers
decontamination services which employ the Rad-Release products for which the cost
varies greatly from project to project. Typical project costs have been approximately
$33-$55/m2.
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6.0 Performance Summary
This section presents the findings from
the evaluation of the Rad-Release I and
Rad-Release II for each performance
parameter evaluated.
6.1 Decontamination Efficacy
The decontamination efficacy (in terms
of %R) attained for Rad-Release I and
Rad-Release II was evaluated for each
concrete coupon used during the
evaluation. When the decontamination
efficacy metrics (%R and DF) of the
four contaminated coupons
decontaminated with each Rad-Release
were averaged together, the average %R
for Rad-Release I was 71% + 13% and
the average DF was 3.9 + 1.5. The
average %R for Rad-Release II was 85%
+ 2% and the average DF was 7.0+1.1.
6.2 Deployment and Operational
Factors
The application of Rad-Release I and
Rad-Release II was performed using a
plastic spray bottles. For Rad-Release I,
the concrete coupons were thoroughly
wetted with Rad-Release I with 3-4
sprays. Then, the solution was worked
into the surface of the coupon by
scrubbing the entire surface of the
coupon once with a scouring pad.
During this evaluation, the initial
application of Rad-Release I took only
10-15 seconds for each coupon. The
next step was a 30 minute dwell time for
the Rad-Release I to reside on the
surfaces of the concrete coupons. After
30 minutes, the surface of the concrete
coupons were thoroughly wetted with a
deionized water/10% nitric acid rinse
solution using another spray bottle and
then removed with a wet vacuum
(vacuuming took about one minute per
coupon). Rad-Release II was used in the
same way but there were two
formulations that went through the
process described above. Therefore, the
Rad-Release I application took
approximately 37 minutes and the Rad-
Release II application took
approximately 65 minutes because the
dwell times were the major factor in the
application time.
The waste generated through use of Rad-
Release I and Rad-Release II was
estimated to be approximately 7 L/m2.
When Rad-Release I and Rad-Release II
are used on surfaces that are
radioactively contaminated, the waste
generated will need to be disposed as
radioactive waste. As used for this
evaluation, only the wet vacuum
required electricity. Scaled up
applications in remote locations may
require additional utilities to provide
means for sprayer or foamer application
and vacuum removal. Minimal training
would be required for technicians using
Rad-Release I and Rad-Release II, and
the surface of the concrete was not
visibly damaged during use. Rad-
Release solutions are not sold as a stand-
alone product but along with the
decontamination service for which the
cost varies greatly from project to
project. Typical projects cost
approximately corresponds to $33-
$55/m2.
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7.0 References
1. ASTM Standard C 150-07, 2. Calibration and Use of Germanium
"Standard Specification for Portland Spectrometers for the Measurement
Cement." ASTM International, West of Gamma Emission Rates of
Conshohocken, PA, www.astm.org, Radionuclides. American National
2007. Standards Institute. ANSI N42.14-
1999. IEEE New York, NY (Rev.
2004).
19
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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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