United States
Environmental Protection
Agency
EPA 600/R-14/323 I October 2014 I www.epa.gov/research
Evaluation of Scalability Challenges
for Radiological Decontamination
Technologies in the Urban
Environment
m
L- »'!
Office of Research and Development
National Homeland Security Research Center
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Evaluation of Scalability Challenges for
Radiological Decontamination Technologies
in the Urban Environment
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NC 27711
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DISCLAIMER
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development's National
Homeland Security Research Center (NHSRC), funded and managed this evaluation through Contract No. EP-C-
10-001 with Battelle Memorial Institute. It has been subjected to the Agency's review and has been approved for
publication. Note that approval does not signify that the contents necessarily reflect the views of the
Agency. Mention of trade names, products, or services does not convey official EPA approval, endorsement, or
recommendation.
Questions concerning this document or its application should be addressed to:
Sang Don Lee
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency
79 T.W. Alexander Dr.
Research Triangle Park, NC 27711
919-541-4531
lee.sangdon@epa.gov
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ACKNOWLEDGMENTS
Contributions of the following individuals and organizations to the development of this document are gratefully
acknowledged.
U.S. Environmental Protection Agency (EPA)
John Drake, Office of Research and Development (ORD)/NHSRC
Emily Snyder, ORD/NHSRC
Terry Stilman, Region 4
James Mitchell, Region 5
John Cardarelli, Office of Emergency Management (OEM), Consequence Management Advisory Team
(CMAT)
Scott Hudson, OEM/CMAT
Battelle Memorial Institute
Idaho National Laboratory
IV
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CONTENTS
DISCLAIMER HI
ACKNOWLEDGMENTS IV
ACRONYMS AND ABBREVIATIONS 2
1.0 INTRODUCTION 4
2.0 CONDUCT OF THE EVALUATION 5
3.0 DEVELOPMENT OF WIDE-AREA DECONTAMINATION TECHNOLOGY COMPENDIUM 6
4.0 IDENTIFICATION OF KNOWLEDGE GAPS AND POTENTIAL SOLUTIONS 7
5.0 DISCUSSION OF SCALABILITY LIMITATIONS 9
6.0 RECOMMENDATIONS TO MITIGATE LIMITATIONS 12
TABLES
TABLE 4-1. SHORT LIST OF WIDE-AREA DECONTAMINATION TECHNOLOGIES 7
APPENDICES
APPENDIX A. DECONTAMINATION TECHNOLOGY INFORMATION SOURCES
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Acronyms and Abbreviations
CBRN
CMAT
DOE
DF
EPA
hr
HSRP
IEEE
ITRC
2
m
NHSRC
NRF
OEM
ORD
QA
QAPP
QC
QMP
%R
ROD
SME
URL
chemical, biological, radiological, nuclear
Consequence Management Advisory Team
U.S. Department of Energy
decontamination factor
U.S. Environmental Protection Agency
hour(s)
Homeland Security Research Program
Institute of Electrical and Electronics Engineers
Interstate Technology and Regulatory Council
square meter(s)
National Homeland Security Research Center
National Response Framework
Office of Emergency Management
Office of Research and Development
quality assurance
quality assurance project plan
quality control
Quality Management Plan
percent removal
radiological dispersal device
subject matter expert
Uniform Resource Locator
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Executive Summary
The U.S. Environmental Protection Agency (EPA) has the responsibility for protecting human
health and the environment from accidental and intentional releases of radiological materials. The
National Response Framework (NRF) (http://www.fema.gov/national-preparedness-resource-
library), Nuclear/Radiological Annex designates EPA as a coordinating or cooperating agency
(depending upon the incident) for environmental response and cleanup. The EPA Office of
Research and Development (ORD) Homeland Security Research Program (HSRP) has conducted
performance evaluations of technologies intended for use in decontamination of urban materials.
These evaluations have been focused on decontamination of various radionuclides from a range of
urban building materials, based on accepted radiological dispersal device (RDD) scenarios. Many
of these technologies may or may not be applicable to decontamination on a wide-area scale. This
report documents an evaluation conducted by the EPA/ORD's National Homeland Security
Research Center (NHSRC) under the HSRP to: (1) identify radiological technologies potentially
applicable to remediation of a wide-area RDD contamination event; (2) identify potential
challenges involved in applying these technologies in the wide-area urban environment; and (3)
provide recommendations for further development of promising methods and processes.
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1.0 Introduction
The U.S. Environmental Protection Agency's (EPA's) Homeland Security Research Program
(HSRP) is helping to protect human health and the environment from adverse effects
resulting from acts of terror. With an emphasis on decontamination and consequence
management, water infrastructure protection, and threat and consequence assessment, the
HSRP is working to develop tools and information that will help detect the intentional
introduction of chemical, biological, or radiological contaminants into water systems, the
containment of these contaminants, the decontamination of buildings and/or water systems,
and waste management resulting from clean-ups.
The National Homeland Security Research Center (NHSRC) provides expert!ce and
capabilities towards addressing the prioritized needs of the HSRP. NHSRC works in
partnership with recognized testing organizations; with stakeholder groups consisting of
buyers, vendor organizations, and permitters; and with technology developers to evaluate the
performance of homeland security technologies. The program evaluates these technologies
by developing evaluation plans that are responsive to the needs of stakeholders, conducting
tests, collecting and analyzing data, and preparing peer-reviewed reports. All evaluations are
conducted in accordance with rigorous quality assurance (QA) protocols to ensure that data
of known and high quality are generated and that results are defensible. High-quality
information is provided that is useful to decision makers in purchasing or applying the
evaluated technologies. Potential users are provided with unbiased third-party information
that can supplement vendor-provided information. Stakeholder involvement ensures that user
needs and perspectives are incorporated into the evaluation design so that useful performance
information is produced for each of the evaluated technologies.
One focus area of these evaluations has been on decontamination of various radionuclides
from a range of urban building materials, based on accepted radiological dispersal device
(RDD) scenarios. Many of these technologies may or may not be applicable to
decontamination on a wide-area scale. This report documents an evaluation conducted by
NHSRC related to HSRP needs to (1) identify radiological technologies potentially
applicable to remediation of a wide-area RDD contamination event, (2) identify potential
challenges and limitations involved in applying these technologies in the wide-area urban
environment and, (3) provide recommendations for further development of promising
methods and processes.
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2.0 Conduct of the Evaluation
A multi disciplinary team was established of EPA radiological decontamination subject
matter experts (SMEs) drawn from both the research and the operational sides (Program and
Regional Offices) of EPA. The team was staffed by representatives from NHSRC, the Office
of Emergency Management (OEM), and the EPA Regions1. To date, the decontamination
technology performance evaluations conducted by NHSRC have been executed in controlled,
laboratory conditions at either bench scale or pilot scale. In order to concentrate on
technologies applicable to the much larger, wide-area scenario it was necessary to objectively
define what constitutes "wide-area" and how to effectively measure wide-area
decontamination performance. After considerable discussion among both the team and other
SMEs with experience in radiological decontamination and field applications, the final
criteria adopted to define the wide-area included (1) a minimum affected area of at least 100
square meters (m2) (the ground floor area of an average size residence) and (2) a minimum
decontamination rate of at least 5 m2/hr. The evaluation consisted of four distinct activities:
1) develop a compendium of all potentially applicable and commercially available
decontamination technologies; 2) identify a subset of these technologies judged to be most
applicable specifically to the wide area scenario; 3) evaluate the subset of technologies to
identify limitations and challenges to their use in the wide-area; and 4) develop
recommendations for follow-on actions to mitigate the identified limitations and challenges.
1 Team members included NHSRC (J. Drake, E. Snyder), EPA Regions (T. Stilman R4, J. Mitchell R5) and
OEM/CMAT (J. Cardarelli, S. Hudson)
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3.0 Development of Wide-Area Decontamination Technology
Compendium
The team developed a draft compendium of currently available and potentially applicable
radiological decontamination technologies. During the initial stage of the compendium
development the EPA project team participated on conference calls to formulate the objectives
for the compendium, provide expert advice on the content and completeness of the
compendium and identify scalability challenges suspected to become important in the
deployment of the candidate technologies. To populate the compendium, a literature review
was conducted which included various government, industry, and public information sources,
as well as various technology vendor websites. Where needed, vendors were contacted to
discuss their technologies to learn more about their potential performance in a wide area
scenario, market availability, and technical maturity. Appendix A provides a list of the primary
information sources used.
The initial draft of the compendium divided available decontamination technologies into three
distinct classes: physical removal (17 technologies), strippable coatings, fixatives, or gels (20
technologies), and liquid/foam chemical technologies (11 technologies). The compendium also
included a list of 19 non-proprietary chemical approaches to radiological decontamination.
This draft was distributed to the EPA project team for review and comment. The team
responded with proposed additional technologies to be included and contributed observations
and insights about what they saw as scalability limitations or attributes of the technologies in
the compendium. Following the EPA project team's review a second conference call was held
to discuss the initial population of the compendium and propose revisions. Below are key
observations/comments from this review:
• Suggested addition of columns for designating radionuclide-specific technologies and
designating best orientation for the technology (horizontal/vertical)
• Suggested developing a shorter list of highest priority technologies
• Suggested a column for "wide-area limitations"
• Suggested development of data quality criteria for evaluation of data (e.g., EPA vs. non-
EPA developed performance data)
• Requested additional technologies (e.g., Nitrocision, microwave scabbier, RDS 2000,
andIntekLH-21).
At several points during development of the compendium revisions were distributed to team
members for review, and to give the opportunity to provide additional input, followed by a
conference call discussion of the current version. After three iterations of this review cycle the
compendium was considered complete.
Following completion of the compendium the team sought to focus on evaluating the
challenges and issues related to deployment of the most promising technologies and to identify
knowledge gaps and/or potential solutions to those challenges and issues. Finally, the team
developed a list of priority technologies suitable for demonstration in a wide-area scenario, and
a summary of scalability limitations and recommendations for mitigating these limitations.
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4.0 Identification of Knowledge Gaps and Potential Solutions
From the original list of 67 potential decontamination technologies or processes, a short list was
developed of those decontamination technologies thought to have the greatest potential for
wide-area applicability with respect to decontamination efficacy, decontamination rate, and
operational factors such as secondary waste collection. The short list includes 10 physical
removal technologies, 7 strippable coatings, fixatives, or gels, and 4 liquid/foam chemical
technologies. Table 4-1 presents the short list of technologies and includes limitations and
challenges noted by the EPA project team. As part of this last step of building the compendium,
the majority of the vendors of technologies on the short list were contacted by the EPA project
team to discuss their view of the wide-area applicability of their product/technology. Feedback
from these vendor discussions was included in the final version of the compendium and in the
limitations/challenges listed in Table 4-1.
Table 4-1. Short List of Wide-Area Decontamination Technologies
Technology
Class
Physical
removal
Vendor
Empire
Abrasive
Equipment
CryoGenesis
Concrete
Cleaning, Inc.
Sponge-Jet,
Inc.
Eco-Blast.Com,
LLC.
The Marcrist
Industries
Pentek, Inc.
K2
Environmental
Services LLC
Roadtec
Decontamination
Technology
Blast N'Vac
CO2 pellet blasting
Centrifugal shot blasting
Soft media blast cleaning
Soda blasting
Concrete shaver
Vacuuming
STARJET™
Milling machines
Principle
of
Operation
Abrasive
grit
Dry ice
blasting
Shot
Blasting
Sponge
Blasting
Blasting
Shaver
Dry
vacuum
Nozzle
Surface
removal
Primary
Limitations/Challenges
Blasting technologies: Concerns about
secondary waste/effluent collection,
decontamination rate, and labor required.
Limited test data.
Destructive to surface; several different
sized units available at various costs
Applicable only to dry, loose
contamination
Water jet for runway cleaning; not tested
on RAD removal.
Minimize effluent removal (soil/road
material, etc.
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Technology
Class
Gels and
strippable
coatings
Liquid and
foam
Vendor
Container
Products
Argonne
National
Laboratory
CBI Polymers,
Inc.
Bartlett
Services, Inc.
Williams
Power
Company
Fram Safety
Products, Inc.)
General
Chemical
Corp.
General
Chemical
Corp.
Allen
Vanguard
Environmental
Alternatives,
Inc.
Environmental
Alternatives,
Inc.
Active
Environmental
Technologies,
Inc.
Decontamination
Technology
Kelly decon
Argonne SuperGel
DeconGel
TLC Stripcoat
Carboline ALARA 1146™
JDL#GP-RDM
DeconPeel_Nuclear_2050
DeconlPaste_2510
Allen-Vanguard UDF
EAI - Environmental
Alternatives, Inc. RRII
EAI - Environmental
Alternatives, Inc. RRI
TechXtract
Principle
of
Operation
Steam
cleaning
with
vacuum
recovery
and
recycle of
water
Absorbent
gel
Gel
strippable
coating
Paint-like
strippable
coating
Paint-like
strippable
coating
Coating
Strippable
coating
Strippable
coating
Foam
Spray
Spray
Chemical
extraction
Primary
Limitations/Challenges
Concerns about efficacy since water only.
Wide-area (WA) spray application not
thoroughly tested; removal may be
difficult.
Minimal independent testing.
Applicable to large scale with little or no
modification; as tested, water rinse and
vacuum removal used
Minimal independent testing.
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5.0 Discussion of Scalability Limitations
For the majority of technologies that showed promise for wide area application (short
list) some limitations or challenges to successful deployment were identified. The
following discusses those limitations judged by the team to be highest priority. Some of
these limitations were identified as pertaining to only a single technology class (e.g.,
surface damage); however some limitations were found to some degree across all
classes of technologies (e.g., absence of independent test data). Summarized by
technology class, the following general limitations/challenges to scalability were
identified:
Physical Removal
Technologies which rely on physically energetic processes such as surface grinding or
media blasting (gaseous, liquid, or entrained abrasives) tend to be, by design, focused to
small areas in order to concentrate the forces required to liberate the contaminants,
which may be either loose, fixed, or both. Since a comparatively small area is being
treated at any given moment, the processes tend to result in a potentially slow
decontamination rate (area per time). To cover a large area requires applying the tool
across the area, using multiple passes. Secondly, such processes typically produce a
contaminated effluent which must be collected to prevent recontamination of the
cleaned surface or escape of contamination to the surrounding environment. Effluent
collection typically relies on some type of vacuum system. Efficient collection of
contaminated effluent, either liquid (slurry blasting), gaseous (air or CO2), or primarily
solid particulates (surface grinding/scabbling), is problematic due to the rough or
uneven geometry typical of infrastructure surfaces. While some surfaces may be
relatively smooth and planar, such as pavement or floors, most surfaces have some
degree of topography which limits both the size of the tool which can be used as well as
the effectiveness of the seal between the tool and the surface being cleaned. Most
physical removal technologies also tend to produce significant quantities of secondary
waste, made up either of contaminated blasting media or material removed from the
surface such as by grinding off the surface layer. Inefficient removal of loosened
contaminant results in recontamination of the surrounding cleaned surfaces, which
reduces overall decontamination efficacy.
Gels and Strippable Coatings
Technologies which employ chemical coatings, both those which cure into a removable
solid (however flexible) and those which remain gelatinous, have been shown to be
efficacious in capturing removable contaminants as well as, in the case of those which
contain chelating agents, contaminants which have may have migrated into the material
matrix of the contaminated surface. These coatings are typically sprayed onto the
surfaces of contaminated infrastructure, which allows for coverage of fairly large areas
in a short amount of time. After some prescribed residence time on the surface these
coatings are subsequently removed along with a certain amount of the contamination.
All of the coating based technologies evaluated in Table 4-2 have been tested or
demonstrated to some extent, and have been shown to be capable of removing most, if
not all, of the loose contamination present during the testing. Some of the products have
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been shown to more efficacious than others, primarily those which include some form
of chelating agent.
The primary factor limiting the efficiency of using such coatings for a wide area
scenario lies in the difficulty of removing the cured or semi-cured coating (which
contains contamination). Cured strippable coatings may be either elastic or semi-elastic.
Elastic coatings are more easily removable, but do tend to tear or stick to uneven
surfaces, which results in the removal process being somewhat time consuming. Semi-
elastic strippable coatings tend to be more brittle and come off the treated surface in
smaller pieces, again resulting in a slower than desirable overall process. All of these
coatings require a certain residence time, either for curing, or for effective completion
of a chelating process. It has been shown that for the cured elastic type of coating, the
thickness of the coating directly affects the ease of removal. A thicker cured coating,
resulting usually from application of multiple coats, tends to tear less enabling quicker
removal. Removal of semi-elastic coatings also may result in bits of coating material
remaining on the surface or in cracks or crevices, which requires a second removal step
to recover these smaller pieces.
Coatings which are intended to remain gelatinous are typically removed by vacuuming.
As with the case of effluent capture, such vacuum tools again rely on maintaining some
degree of seal between the tool and the surface being cleaned.
Liquids and Foams
The last category of decontamination technology identified for potential wide area
applicability is that which includes liquids and foams. Liquid based technologies, such
as the EAI products shown in Table 4-2, are typically sprayed on, and after some
residence time are removed by vacuuming, often with an intermediate rinse step. Some
liquid based products also specify a final rinse and vacuum step as part of the
procedure. Initial application of a liquid technology by spraying is a fairly time-
efficient process. A significant area can be treated in a short amount of time. The
vacuum removal step, however, is time consuming for the same reasons as discussed
previously. And it is this vacuum removal step which ultimately produces results in
decontamination of the surface.
Similar to the liquid based products, foam based products are also easy and quick to
apply to the surface, but also require a vacuum removal step, and possibly a final rinse.
In all cases where a rinse step is included the potential exists for runoff of rinsate and
suitable collection precautions must be taken to contain and collect the rinsate. This
further adds to the time required to perform complete decontamination operations.
10
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Lack of Efficacy Data
A significant factor to consider when deciding on a technology to deploy in any given
scenario is decontamination efficacy. For the particular materials which must be
decontaminated, under the environmental conditions being encountered, and for the
particular radionuclide being addressed, what efficacy might be expected from the
decontamination process being proposed? Decontamination efficacy is usually thought
of in terms of a comparison between the amount of contamination present after
decontamination operations relative to that which was initially present. It can be
expressed in terms of percent contamination removed or as a decontamination factor,
where the decontamination factor is defined as the ratio of the amount or concentration
of the contaminant before treatment to the amount or concentration after treatment. In
this case, (%R) = (1 - 1/DF)*100 or equivalent^, DF = 1007(100 - %R).
Decontamination efficacy evaluations have been conducted by manufacturers or
vendors of technologies, and also by third party testing programs such as those
conducted by EPA and the U.S. Department of Energy (DOE). There currently are no
widely accepted or codified efficacy test procedures, and therefore all efficacy data that
does exist must be carefully examined for its applicability to the particular
decontamination scenario being considered. That said, reliable efficacy data generated
by an independent test facility does exist for most of the technologies shown in Table 4-
2, though not for all of them. The fact that there may be no reliable efficacy data
available for a given technology is a significant limitation.
11
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6.0 Recommendations to Mitigate Limitations
Most of the scalability limitations identified involve operational factors such as
decontamination rate, effluent control, and secondary waste generation. In general
these operational limitations could be quantified and evaluated by demonstrating the
technology in a setting which reflects a wide-area scenario (surface area greater than
100 m2 and application rate greater than 5 m2/hr) and evaluating the results. The
absence of reliable independent test data could be rectified by conducting rigorous
laboratory testing, using substrates and radionuclides of common interest. Limitations
inherent in the nature of a given technology (e.g., some physical removal technologies
being destructive to the surfaces being decontaminated) may not be amenable to
improvement, but may be tolerable under certain circumstances, such as with a
degraded but acceptable end state following decontamination. The following
summarizes recommended follow-on activities to mitigate the identified limitations:
1. Demonstrate promising technologies at a wide-area scale
Conduct full scale demonstrations of those technologies which show the greatest
promise of success without the need for significant modification. Structure
demonstrations with attention to factors affecting decontamination rate to identify
potential improvements in equipment or protocols (e.g., removal process for strippable
coatings). Demonstrations should be performed under realistic conditions on structures
designed to replicate common infrastructure.
2. Conduct efficacy evaluations
Conduct efficacy evaluations of technologies for which no independent performance
data exists and which show promise for wide-area scale demonstration. Evaluations
should be based on proven methods and to the extent practicable be relatable to such
data that exists for similar or competing technologies. Given the considerable
experience in decontamination efficacy testing that currently resides within the Agency
and other government entities, EPA should develop guidance which can be used by
manufacturers, technology end users, and emergency recovery planners to evaluate the
expected performance of the range of decontamination technologies available.
3. Conduct research to address design-based limitations
Collaborate with technology providers to address design-based limitations such as
improved effluent capture and reduced secondary waste production. EPA should
provide information as to the strengths and weaknesses of the technologies listed in
Table 4-1 to the respective technology manufacturers. Operational experience and
judgement of subject matter experts may encourage manufacturers to address design
related limitations and produce improved technologies. In cases of specific promising
technologies which have been evaluated for decontamination performance and shown
to perform well, and have been successfully demonstrated at full scale, additional
funding mechanisms may be sought - such as through EPA's mall Business Innovative
Research Program.
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Appendix A
Decontamination Technology Information Sources
(last access dates 9/11/2014)
Source
Technology Reference Guide
for Radiologically Contaminated
Surfaces
ITRC Decontamination and
Decommissioning of
Radiologically Contaminated
Facilities
Urban Remediation and
Response Project Prepared for
New York City Department of
Health and Mental Hygiene
EPA Technology Testing and
Evaluation Program reports
Knovel
Compendex
Science Direct
IEEE Explorer
Proquest
Defense Technical Information
Center
Technology vendors
Source Type
EPA Document
ITRC Document
DOE Document
EPA Documents
Technical Information database
Technical Information database
Technical Information database
Technical Search Engine
Technical Information database
Technical Information database
websites
Reference Locator
http://www.epa.aov/radiation/docs/cleanup
/402-r-06-003.pdf
http://www.itrcweb.orq/Guidance/GetDocu
ment?documentlD=75
http://www.ntis.aov/search/product.aspx?
ABBR=DE2009965879
http://www.epa.gov/nhsrc/pubs.html
(listed under Radiological Contamination)
http://www.elsevier.com/online-
tools/knovel
http://www.elsevier.com/elsevier-
products/compendex
www.sciencedirect.com
http://ieeexplore.ieee.ora/Xplore/home.isp
http://www.proauest.com/en-US/
http://www.dtic.mil/dtic/
various
13
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Environmental Protection
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