&EPA
United States
Environmental Protection
Agency
EPA 600/R-11/016 | July 2011 ] www.epa.gov/ord
Industrial Contractors
Supplies, Inc. Surface Dust
Guard with Wire Brush for
Radiological Decontamination
TECHNOLOGY EVALUATION REPORT
Office of Research and Development
National Homeland Security Research Center

-------
EPA 600-R-11-016
July 2011
Technology Evaluation Report
Industrial Contractors Supplies, Inc.
Surface Dust Guard with Wire Brush for
Radiological Decontamination
United States Environmental Protection Agency
Cincinnati, OH 45268

-------
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
li

-------
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. 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.
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
111

-------
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
Lukas Oudejans
David Musick
Kathy Hall
Eletha Brady-Roberts
Jim Mitchell
University of Tennessee
Howard Hall
United States Department of Energy's Idaho National Laboratories
Battelle Memorial Institute
iv

-------
Contents
Disclaimer	ii
Foreword	iii
Acknowledgments	iv
Abbreviations/Acronyms	vii
Executive Summary	viii
1.0 Introduction	1
2.0 Technology Description	3
3.0 Experimental Details	4
3.1	Experiment Preparation	4
3.1.1	Concrete Coupons	4
3.1.2	Coupon Contamination	5
3.1.3	Measurement of Activity on Coupon Surface	6
3.1.4	Surface Construction Using Test Stand	6
3.2	Evaluation Procedures	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	9
4.2.3	Data Quality Audit	10
4.3	QA/QC Reporting	10
5.0 Evaluation Results	11
5.1	Decontamination Efficacy	11
5.2	Deployment and Operational Factors	12
6.0 Performance Summary	15
6.1	Decontamination Efficacy	15
6.2	Deployment and Operational Factors	15
7.0 References	16
v

-------
Figures
Figure 2-1. Angle grinder equipped with SDG is shown (left). Wire brush (right)	3
Figure 3-1. Demonstration of contaminant application technique	5
Figure 3-2. Containment tent: outer view (left) and inner view with test stand
containing contaminated coupons (right)	6
Figure 3-3. SDG-WB being applied to concrete coupon	7
Figure 5-1. Concrete coupons demonstrating surface damage	13
Tables
Table 3-1. Characteristics of Portland Cement Clinker Used to Make Concrete
Coupons	4
Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies	8
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check	9
Table 5-1. Decontamination Efficacy Results	12
Table 5-2. Operational Factors Gathered from the Evaluation	14
vi

-------
Abbreviations/Acronyms
ANSI
American National Standards Institute
ASTM
American Society for Testing and Materials
BQ
Becquerel
Cs
cesium
cfm
cubic feet per minute
cm
centimeters
cm2
square centimeters
DARPA
Defense Advanced Research Projects Agency
DF
decontamination factor
DHS
U.S. Department of Homeland Security
DOD
Department of Defense
EPA
U.S. Environmental Protection Agency
Eu
europium
Ft
feet
HEPA
High Efficiency Particulate Air
IEEE
Institute of Electrical and Electronics Engineers
INL
Idaho National Laboratory
keV
kilo electron volts
kg
kilogram
mg
milligram
mL
milliliter
L
liter
m
meter
m2
square meters
jj.Ci
microCurie
NHSRC
National Homeland Security Research Center
NIST
National Institute of Standards and Technology
ORD
Office of Research and Development
%R
percent removal
PE
performance evaluation
QA
quality assurance
QC
quality control
QMP
quality management plan
RDD
radiological dispersion device
RML
Radiological Measurement Laboratory
RSD
relative standard deviation
SDG
Industrial Contractors Supplies, Inc. Surface Dust Guard
SDG-WB
Industrial Contractors Supplies, Inc. Surface Dust Guard with a wire brush
TSA
technical systems audit
TTEP
Technology Testing and Evaluation Program
Th
thorium
V
volt
WB
wire brush
vii

-------
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 performance of the Industrial Contractors
Supplies, Inc. Surface Dust Guard (SDG) with a wire brush (WB) and its ability to
remove radioactive cesium (Cs)-137 from the surface of unpainted concrete.
Experimental Procedures. The Industrial Contractors Supplies, Inc. SDG is a vacuum
shroud that can be attached to almost any commercially available handheld grinder or
polisher (e.g. Bosch, DeWalt, and Hitachi, etc). During this evaluation the SDG was used
with a Makita 9564CV angle grinder equipped with a WB. (Hereafter this combination
will be referred to as the SDG-WB.) This technology decontaminates by brushing the
surface layer and collecting the resulting secondary waste using a vacuum connected to
the SDG. 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. Each coupon was brushed with the
SDG-WB, and 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 attained by the SDG-WB was evaluated for each
concrete coupon used during the evaluation. When the decontamination efficacy metrics
(%R and DF) of the eight contaminated coupons were averaged together, the average %R
for the SDG-WB was 38 ± 7% and the average DF was 1.62 ± 0.20. Hypothesis testing
was performed to determine if there were significant differences between the %R values
determined for the coupons in each row (top, middle, and bottom) of the test stand. A
small but significant difference was found between the top and middle rows of coupons.
The SDG-WB could decontaminate a vertical surface at a rate of approximately 2.7
square meters (m2) per hour. The SDG-WB caused minimal surface destruction (although
there was significant discoloration). The texture of the coupon surface may be important
to the efficacy of the SDG-WB and similar brush radiological decontamination
technologies. The WB is not aggressive enough to cut through irregularities in concrete
surfaces, which may limit its effectiveness on uneven surfaces.

-------
A very limited evaluation of cross-contamination was performed. During an actual
decontamination of a vertical surface, the higher elevation surfaces would likely be
decontaminated first, possibly exposing the lower surface to secondary contamination. To
simulate an actual scenario, one uncontaminated coupon was placed in the bottom row of
the test stand and decontaminated using the SDG-WB in the same way as the other
coupons. Following decontamination, this uncontaminated coupon did not contain
measurable activity, suggesting that cross contamination was minimal.
Overall, the SDG was not entirely effective at containing the secondary waste. During
the evaluation a significant amount of dust was visible and the radiological control
technicians found a small, but measurable, level of airborne radiological activity. The
dust collected by the vacuum was not analyzed for gamma radiation.
IX

-------
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, through its Technology Testing
and Evaluation Program (TTEP), works
in partnership with recognized testing
organizations; with stakeholder groups
consisting of buyers, vendor
organizations, and permitters; and with
the participation of individual
technology developers in carrying out
performance tests on homeland security
technologies. The program evaluates the
performance of 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, and
in planning clean-up operations. 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, NHSRC recently
evaluated the performance of the
Industrial Contractors Supplies, Inc.
(Huntingdon, PA) Surface Dust Guard
(SDG) with an angle grinder equipped
with a wire brush (WB) (hereafter
referred to as the SDG-WB) in removing
radioactive isotope Cs-137 from
concrete. A peer-reviewed test/QA plan
was developed according to the
requirements of the quality management
plan (QMP) for TTEP. The evaluation
generated the following performance
information:
• Decontamination efficacy, defined as
the extent of radionuclide removal,
1

-------
and the possibility of cross-
contamination
• 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.
This evaluation took place from August
11, 2009 until October 13, 2009. 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 SDG-WB. The
contractor, Battelle, and EPA were
responsible for QA oversight of this
evaluation. The Battelle QA Manager
conducted both a technical systems audit
(TSA) and a data quality audit of the
evaluation data.
2

-------
2.0 Technology Description
The following description of the
Industrial Contractors Supplies, Inc.
SDG is based on information provided
by the vendor and was not verified
during this evaluation.
The Industrial Contractors Supplies, Inc.
SDG is a vacuum shroud that can be
attached to almost any commercially
available handheld grinder or polisher
(e.g. Bosch, DeWalt, and Hitachi, etc)
with a five inch wheel (diamond,
carbide, WB, etc.). During this
evaluation the SDG was used with a
Makita 9564CV angle grinder equipped
with a WB (hence, SDG-WB). This
technology decontaminates by brushing
the surface layer and collecting the
resulting secondary waste using a high
efficiency particulate air (HEPA)
vacuum connected to the SDG. The
vacuum used with the SDG required 110
volt (V) electricity and generated a flow
of 136 cubic feet per minute (cfm). The
angle grinder component of the SDG-
WB was also powered by 110 V
electricity; according to vendor
specifications, it operates at speeds up to
10,500 revolutions per minute. Figure 2-
1 shows the components of the SDG-
WB
Figure 2-1. Angle grinder equipped with SDG is shown (left). Wire brush (right).
3

-------
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 describes the cement
clinker used in the concrete mix. For
Type II Portland cement, the American
Society for Testing and Materials
(ASTM) Standard C 150-71 specifies
that tricalcium aluminate should account
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.
Table 3-1. Characteristics of Portland Cement Clinker
	Used to Make Concrete Coupons	
	Cement Constituent	Percent of Mixture
Tricalcium Silicate	57.6
Dicalcium Silicate	21.1
Tricalcium Aluminate	4.5
Tetracalcium Aluminoferrite	8.7
Minor Constituents	8.1
The wet concrete was poured into 0.9
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. The
concrete was representative of exterior
concrete commonly found in urban
environments in the United States as
shown by INL under a previous project
sponsored by the U.S. Department of
Defense (DOD), Defense Advanced
4

-------
Research Projects Agency (DARPA) and
U.S. Department of Homeland Security
(DHS).2
3.1.2 Coupon Contamination
Eight coupons were contaminated by
spiking individually with 2.5 milliliters
(mL) of aqueous solution that contained
0.26 milligrams (mg)/liter (L) Cs-137 as
a solution of cesium chloride,
corresponding to an activity level of
approximately 1 microCurie (juCi) over
the 225 square centimeters (cm )
surface. Application of the Cs in an
aqueous solution was justified because
even if Cs were dispersed in a particle
form following a radiological dispersion
device ( ROD) 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 dry
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 project2) and described in
detail in the test/QA plan.
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 L per minute created
a turbulent flow through the first
syringe. When the contaminant solution
in the second syringe was introduced,
the solution became nebulized by the
turbulent air flow. A fine aerosol was
ejected from the tip of the first syringe
creating a controlled and uniform spray
of fine liquid droplets onto the coupon
surface. The contaminant spray was
applied all the way to the edges of the
coupon which were taped (after having
previously been sealed with polyester
resin) to ensure that the contaminant was
applied only to the 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
5

-------
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 the
ETR180. 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
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 (PCGAP, Idaho
National Engineering and Environmental
Laboratory, Idaho Falls, ID;
INEEL/EXT-2000-00908;
http://www.inl.gov/technicalpublications
/Documents/3318133.pdf). 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 was fabricated that held three rows
of three concrete coupons. The test
stand, approximately 9 feet (ft) x 9 ft,
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 and
decontaminated using the SDG-WB in
the same way as the other coupons. This
coupon was placed there to observe
possible secondary contamination
caused by the decontamination higher on
the wall. Figure 3-2 shows the
containment tent and the test stand
loaded with concrete coupons.
Figure 3-2. Containment tent: outer view (left) and inner view with test stanc
containing contaminated coupons (right).
6

-------
3.2 Evaluation Procedures
The containment tent consisted of two
rooms. One room contained the test
stand to hold the contaminated coupons;
the other room (the shorter part of the
tent as shown in Figure 3-2) held the
vacuum. An opening in the tent wall
between the two rooms was just large
enough to allow the vacuum hose
connected to the SDG-WB to pass
through. The tent opening was taped
closed around the hose prior to the start
of the evaluation. Figure 3-3 shows the
vacuum hose connecting to the SDG as
the operator applies the SDG-WB to a
concrete coupon.
The nine concrete coupons in the test
stand were brushed with the SDG-WB
starting with the top row and working
from left to right, then proceeding to the
middle and bottom rows. The coupons
were scrubbed in this manner 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 SDG-WB was
connected to the vacuum and used at full
power for 30 seconds on each coupon,
enough time to ensure that the entire
surface of each coupon had been
covered. This application of the SDG-
WB would correspond to a rate of 0.05
m2 per minute. The temperature and
relative humidity were recorded before
and after the approximately one hour
test. These conditions did not vary
significantly in the room where the
evaluation was performed . Over the
duration of testing, the temperature was
22.3 °C and the relative humidity was
24%.

Jl
V
4#
A ~

i" . • %
/ 1
it


ill


111
/ fcJ
> -1
~ W
y
\

I
!
Figure 3-3. SDG-WB being applied to concrete coupon.
7

-------
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
once each week. The calibration was
performed in accordance with
standardized procedures from the
American National Standards Institute
(ANSI) and the Institute of Electrical
and Electronics Engineers (IEEE).3 In
brief, detector energy was calibrated
using thorium (Th)-228 daughter gamma
rays at 238.6, 583.2, 860.6, 1620.7, and
2614.5 kilo electron volts (keV). This
calibration was performed three times
during the overall project and
documented by the RML. Table 4-1
gives the difference between the known
energy levels and those measured
following calibration. The energies were
compared to the previous 30 calibrations
to confirm that the results were within
three standard deviations of the previous
calibration results. The calibrations are
shown for the detector used during this
evaluation. All the calibrations fell
within this requirement.
Table 4-1. Calibration Results - Difference from Th-228 Calibration Energies
	Calibration Energy Levels (keV)	
Energy 1 Energy 2 Energy 3 Energy 4 Energy 5
Date	238.632 583.191 860.564 1620.735 2614.533
8-25-2009	-0.005	0.014	-0.031 -0.199 0.031
9-21-2009	-0.003	0.009	-0.040 -0.125 0.015
10-13-2009	-0.003	0.008	-0.011 -0.180 0.020
Gamma ray counting was continued on
each coupon until the activity level of
Cs-137 on the surface had a relative
standard deviation (RSD) of less than
2%. This RSD occurred within the initial
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.
8

-------
The background activity of the concrete
coupons was determined by analyzing
nine arbitrarily selected coupons from
the stock of concrete coupons used for
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 2x10"4 |iCi on these coupons.
Because the background activity was not
detectable (and the detectable level was
more than 3,500 times lower than the
post-decontamination activity levels), no
background subtraction was required.
Throughout the evaluation, a second
measurement was taken on 10 coupons
in order to provide duplicate
measurements to evaluate the
repeatability of the instrument. Half of
the duplicate measurements were
performed after contamination prior to
application of the decontamination
technology and half were performed
after decontamination. Five of the
duplicate pairs showed no difference in
activity levels between the two
measurement; the other five duplicate
pairs had a difference of 2% between the
two measurements, 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 to the accepted NIST value.
Results within 7% of the NIST value are
considered to be within acceptable
limits. The Eu-152 activity comparison
is a routine QC activity performed by
INL, but for the purposes of this
evaluation serves as the performance
evaluation (PE) audit, an audit that
confirms the accuracy of the calibration
standards used for the instrumentation
critical to the results of an evaluation.
Table 4-2 gives the results of each of the
audits applicable for the duration of the
evaluation. All results are below the
acceptable difference of 7%.
Table 4-2. NIST-Traceable Eu-152 Activity Standard Check



Relative

NIST Activity
INL RML
Percent
Date
(BQ)
Result (BQ)
Difference
8-18-2009
124,600
122,400
2%
9-10-2009
124,600
122,600
2%
10-12-2009
124,600
122,300
2%
4.2.2 Technical Systems Audit
A TSA was conducted during testing at
INL to ensure that the evaluation was
performed in accordance with the
test/QA plan and the TTEP QMP. As
part of the audit, the actual evaluation
procedures were compared with those
specified in the test/QA plan, and the
data acquisition and handling procedures
were reviewed. No significant adverse
findings were noted in this audit. The
9

-------
records concerning the TS A are stored
indefinitely with the Battelle QA
Manager.
4.2.3 Data Quality Audit
The Battelle QA Manager verified all of
the raw data acquired during the
evaluation and transcribed into
spreadsheets for use in the final report.
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 and the QMP. The Battelle
QA Manager prepared the draft
assessment report and sent it to the Test
Coordinator and Battelle TTEP Program
Manager for review and approval. The
Battelle QA Manager then sent the final
assessment report to the EPA QA
Manager and Battelle staff.
10

-------
5.0 Evaluation Results
5.1 Decontamination Efficacy
The decontamination efficacy of the
SDG-WB was measured for each
contaminated coupon in terms of percent
removal (%R) and decontamination
factor (DF). Both of these measurements
provide a means of representing the
%R = (1-Af/Ao) x
where A0 is the radiological activity
from the surface of the coupon before
application of the SDG-WB 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.
Table 5-1 gives the %R and DF for the
SDG-WB. All coupons were oriented
vertically. The target activity for each of
the contaminated coupons (pre-
decontamination) was within the
acceptable range of 1 |iCi ± 0.5 |iCi. The
overall average activity (plus or minus
one standard deviation) of the
extent of decontamination accomplished
by a technology. The %R gives the
extent of decontamination 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:
100% and DF = A0/Af
contaminated coupons was 1.16 |iCi ±
0.05 |iCi, a variability of 4%. The post-
decontamination coupon activities were
less than the pre-decontamination
activities showing an overall reduction
in activity. The %R (calculated as
described above) averaged 38% ± 7%
and the DF averaged 1.62 ± 0.20.
Overall, the %R ranged from 28% to
51%) and the DF ranged from 1.38 to
2.06. Seven of the eight %>R values fell
within the range of 28% to 41%. The
first coupon, with a %R of 51%>, fell just
outside of that range, with no obvious
explanation for the slightly higher result.
11

-------
Table 5-1. Decontamination Efficacy Results
Coupon
Location in
Test Stand
Pre-Decon Activity
jiCi / Coupon
Post-Decon Activity
jiCi / Coupon
%R
DF
Top left
1.11
0.54
51
2.06
Top middle
1.16
0.72
38
1.61
Top right
1.19
0.72
40
1.66
Center left
1.24
0.73
41
1.69
Center middle
1.08
0.74
31
1.46
Center right
1.18
0.85
28
1.38
Bottom left
1.17
0.73
38
1.61
Bottom right
1.14
0.75
34
1.51
Average
Std. Dev
1.16
0.05
0.72
0.09
38
7
1.62
0.20
Paired t-tests were performed at a 95%
confidence interval to determine whether
location (top, middle, or bottom) on the
test stand affected the decontamination
efficacy. The average %R for the top
row (43% ± 7%) of coupons was slightly
higher than the middle (33% ± 7%) and
bottom (36%) ± 3%) rows. The values for
the %R on the top row were significantly
different from those for the center row at
the 95% confidence interval, but not
significantly different from the bottom
row, which also had a lower average
%R. It is possible that the WB began
wearing down and became duller after
application to several coupons, thus
diminishing efficacy. The bottom middle
coupon was not contaminated to test the
possibility of cross-contamination.
Activity of the uncontaminated coupon
was measured after all nine coupons had
been decontaminated using the SDG-
WB. No activity was detected on the
uncontaminated coupon, suggesting that
cross-contamination due to the
application of the SDG-WB was
minimal.
5.2 Deployment and Operational
Factors
A number of operational factors were
documented by the SDG-WB operator.
One of the factors was damage to the
surface of the concrete coupons. The
photographs in Figure 5-1 show one
concrete coupon that has not been
subjected to any decontamination
technique (on the left) and one that has
been decontaminated using the SDG-
WB (on the right). While difficult to see
in these pictures, the surface of the
treated coupon was minimally damaged.
However, the SDG-WB did cause
significant discoloration to the surface of
the concrete. This discoloration was
likely due to the transfer of filings from
the WB. While the structure of the
concrete remained sound, the SDG-WB
caused it to look very dirty and
potentially unattractive, depending on
the type of surface (e.g., building,
sidewalk, etc.) that was being
decontaminated.
12

-------
Figure 5-1. Concrete coupons demonstrating surface damage.
Other important factors to consider are
the personal protection of the technology
operators and the secondary waste
management of a decontamination
technology. During this evaluation, the
RTCs required the operators to wear full
anti-contamination personal protective
equipment that included a full face
respirator with supplied air. This level
of personal protection was required
because of the likelihood of airborne
radiological contamination due to the act
of brushing. However, each situation
will need to be considered independently
by local RCTs to determine the proper
level of personal protection. Overall, the
SDG was not entirely effective at
containing the secondary waste. During
the evaluation a significant amount of
dust was visible and the RCTs found a
small, but measurable, level of airborne
radiological activity. The visible dust
and airborne activity were attributed to
ineffective effluent capture at the tool
seal-to-concrete interface. The HEPA
filtered vacuum was in a separate room
of the tent and was unlikely to have
contributed to the airborne
contamination/dust. During an actual
ROD decontamination operation, the
potential for release of airborne
radiological activity, would be a safety
concern and would likely increase the
risk of re-contamination of cleaned
areas.
Table 5-2 summarizes qualitative and
quantitative practical information gained
by the operator during the evaluation of
the SDG-WB. All of the operational
information was gathered during use of
SDG-WB on the concrete coupons
inserted into the test stand. Some of the
information given in Table 5-2 could
differ if the SDG-WB were applied to a
larger surface or a surface that was more
smooth or more rough and jagged than
the concrete coupon used during this
evaluation.
13

-------
Table 5-2. Operational Factors Gathered from the Evaluation
Parameter
Description/Information
Decontamination
rate
Technology Preparation: 5 minutes to attach WB and SDG to angle grinder.
Application: 30 seconds per concrete coupon used during this evaluation
corresponds to an application rate of approximately 2.7 m2/hour; less or more
time per coupon may result in different levels of radiological
decontamination.
Applicability to
irregular surfaces
Irregular surfaces may be detrimental to the efficacy of the SDG-WB and
similar brush radiological decontamination technologies. The WB is not
aggressive enough to cut through irregularities in concrete surfaces so that
may limit the effectiveness on uneven surfaces.
Skilled labor
requirement
The SDG-WB is an extremely basic technology requiring minimal training.
Adequate training would likely include a few minutes of orientation so the
operator is familiar with the power switches on the vacuum and the SDG-
WB.
The SDG-WB weighs approximately 2 kilograms (kg). The operator during
this evaluation experienced a significant level of exertion as he completed the
evaluation. The weight of the SDG-WB, in combination with the additional
weight and awkwardness of the attached vacuum line, increased the level of
effort required to use the SDG-WB. Depending on what row of the test stand
was being used, the operator was required to bend over, stand on the floor or
stand on a ladder. These factors will exclude some people from operating the
SDG-WB. However, most people who are used to performing physical labor
should not have any problem operating the SDG-WB.
Utilities
requirement
110 V power for both the SDG-WB and a 136 cfm vacuum.
Portability
The limiting factors of portability for the SDG-WB will include the
availability of power and the ability to connect to the vacuum by staying close
enough to the vacuum or by having a vacuum hose of adequate length.
Decontamination
media
The same WB was used for all nine coupons that were decontaminated.
Secondary waste
management
Some dust was expelled from the WB and vacuum shroud during testing. The
radiological control technicians who observed the testing collected airborne
particulate and detected small, but measurable amounts of activity in the air
during evaluation of the SDG-WB. The activity of the dust collected by the
vacuum or vacuum filter was not measured quantitatively.
Surface damage
See description and picture in text.
Cost
$1,000 for the entire system, including the angle grinder, SDG, and vacuum.
The SDG alone costs $235.
14

-------
6.0 Performance Summary
This section presents the findings from
the evaluation of the SDG-WB for each
performance parameter evaluated.
6.1	Decontamination Efficacy
The decontamination efficacy (in terms
of %R) attained by the SDG-WB was
evaluated for each concrete coupon used
during the evaluation. When the
decontamination efficacy metrics (%R
and DF) of the eight contaminated
coupons were averaged together, the
average %R for the SDG-WB was 38 ±
7% and the average DF was 1.62 ± 0.20.
Hypothesis testing was performed to
determine if there were significant
differences between the %R values
determined for the coupons in each row
(top, middle, and bottom) of the test
stand. A small but significant difference
was found between the top and middle
rows of coupons.
6.2	Deployment and Operational
Factors
The SDG-WB could decontaminate a
vertical surface at a rate of
approximately 2.7 m per hour. The
SDG-WB caused minimal surface
destruction (although there was
significant discoloration). The texture of
the coupon surface may be important to
the efficacy of the SDG-WB and similar
brush radiological decontamination
technologies. The WB is not aggressive
enough to cut through irregularities in
concrete surfaces, which may limit its
effectiveness on uneven surfaces.
A very limited evaluation of cross-
contamination was performed. During an
actual decontamination of a vertical
surface, the higher elevation surfaces
would likely be decontaminated first,
possibly exposing the lower surface to
secondary contamination. To simulate an
actual scenario, one uncontaminated
coupon was placed in the bottom row of
the test stand and decontaminated using
the SDG-WB in the same way as the
other coupons. Following
decontamination, this uncontaminated
coupon did not contain measurable
activity, suggesting that cross
contamination was minimal.
Overall, the SDG was not entirely
effective at containing the secondary
waste. During the evaluation a
significant amount of dust was visible
and the radiological control technicians
found a small, but measurable, level of
airborne radiological activity. The dust
collected by the vacuum was not
analyzed for gamma radiation.
15

-------
7.0 References
1.	ASTM Standard C 150-07,
"Standard Specification for Portland
Cement." ASTM International, West
Conshohocken, PA, www.astm.org.
2007.
2.	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.
3. Calibration and Use of Germanium
Spectrometers for the Measurement
of Gamma Emission Rates of
Radionuclides. American National
Standards Institute. ANSIN42.14-
1999. IEEE New York, NY (Rev.
2004).
16

-------
&EPA
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

-------