EPA
EPA/600/B-17/358 I Se[tember 2017
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
Hot Spot Calculator to Optimize
Radiological Cleanup Decisions
Office of Research and Development
Homeland Security Research Program
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Version
HOT SPOT CALCULATOR: A SPREADSHEET
TOOL FOR OPTIMIZING RADIOLOGICAL
CLEANUP DECISIONS
U.S. Environmental Protection Agency
III hi I
HcrrsFor
CALCLIATOR
User Guide
AMS Decon Calculator
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Diamond Flap Wheel
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U.S. I•; N V1 R C) N M I•; N'1" A L PRO'l'Ii€'!' 1 O N AG1 iN € Y
Hot Spot Calculator (HSC)
U.S. Environmental Protection Agency
Homeland Security Research Program
Research Triangle Park, NC 27711
Disclaimer
This tool was created by the U.S. Environmental Protection Agency through its Office of Research and
Development's National Homeland Security Research Center (NHSRQ. The contents of this workbook
do not necessarily reflect the views of the Agency. The EPA has not validated these results against any
real-world radiological contamination scenarios. Mention of trade names, products, or services does not
convey official EPA approval, endorsement, or recommendation.
Acknowledgements:
Timothy Boe, Sang Don Lee, Paul Lemieux, Kathy Hall, Matthew Magnuson, Eugene Jablonowski, and
Jim Mitchell
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Acronym /Abbreviation List
2D 2-Dimensional
3D 3-Dimensional
AMS Advanced Medical Systems
HSC Advanced Medical Systems Hot Spot Calculator
Co Cobalt
EPA's Environmental Protection Agency's
GB gigabyte
GeGI Germanium Gamma-Ray Imager
GHz gigahertz
m meter
NHSRC National Homeland Security Research Center
PPE Personnel Protective Equipment
RAM random access memory
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Table of Contents
Acronym /Abbreviation List iii
Ible of Contents iv
Introduction 1
How to Use This Manual 1
Point(s) of Contact 1
Description 2
3D Model 2
Systems Approach 3
Design 4
Expansion 5
Assumptions 5
Installation & Setup 6
Minimum System and Software Requirements 6
Quick Start User Guide 7
Combining Gamma Ray & 3D Blueprint Imagery 7
Home 8
Site Info 9
Decon Factors 10
Miscellaneous Expenses 10
Radionuclide Distribution 11
Radioactive Decay 11
Setup & Results 11
Charts 12
Troubleshooting 14
Bibliography 15
iv
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INTRODUCTION
I ntrod uction
Easily deployable spreadsheet for rapidly evaluating decontamination options using the
magnitude and extent of contamination derived from gamma-ray imaging
The U.S. Environmental Protection Agency's (EPA's) Hot Spot Calculator (HSC) is a novel tool for
evaluating mechanical decontamination technologies and the associated resource demand required to
remediate areas of elevated radioactive contamination identified by gamma-ray imaging technology. The
HSC was developed to help decision makers better understand potential options for decontamination
and the consequences those options may have on remediation efforts (i.e., systems approach).
ICON KEY
E7 Valuable information purp0se of this manual is to provide the necessary information to operate the HSC
^ Optional tool. Described in this manual are methods for installing, configuring, and operating HSC.
Example Before operating HSC, it is highly recommended that users have previous experience in
using Microsoft Excel®. The "icon key" to the left contains symbols intended to provide
support within a particular area. Look for these symbols throughout this guide for important information and
additional guidance.
Point(s) of Contact
Timothy Boe
US EPA Office of Research and
Development
National Homeland Security
Research Center
NHSRC/DCMD
919-541-2617
919-541-0496 fax
boe.timothy@, epa.gov
Sang Don Lee
US EPA Office of Research and
Development
National Homeland Security
Research Center
NHSRC/DCMD
919-541-4531
919-541-0496 fax
lee.sangdon@epa.gov
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USER GUIDE
DRAFT
In July of 2015, Region 5 requested EPA's National Homeland Security Research Center's (NHSRC) support in
determining cost effective decontamination options for remediating a radiologically contaminated facility in
Cleveland, OH. The facility, otherwise known as the Advanced Medical Systems (AMS) site, manufactured
Cobalt-60 (Co-60) sealed sources until production ceased in 1991. The manufacturing facility, which is located
adjacent to a densely populated residential neighborhood, remains radioactive. Using a gamma-ray imaging
device, a number of areas of elevated activity were identified at the facility by Region 5. Due to the potential cost
of remediating the site in its entirety, NHSRC scientists were tasked with identifying cost effective
decontamination options and to evaluate the impact of decontamination decisions on remediation efforts. From
this need, the HSC tool was developed. The tool uses contamination level (^.Ci) and surface area information
(m2), derived from gamma-ray imaging technology, to help guide decision makers in determining the most cost-
and time-effective decontamination approach with respect to overall outcome of the remediation effort. Results
are calculated based on two inputs: 1) decontamination technology and 2) targeted radioactivity. Using these two
inputs, the tool estimates the number of applications (i.e., passes) of a given decontamination technology needed
to achieve a specified activity. Decontamination cost, time, activity, and waste estimates are calculated as a
function of decontamination technology and number of passes. Upon selecting the appropriate approach, the
results are summarized in an easy to read format.
The tool was built on two different, yet complementary approaches: 1) transformation of 2-Dimensional (2D)
gamma ray radiation field information onto a 3-Dimensional (3D) model for estimating surface area and surface
contamination; and 2) an approach for estimating the impacts of decisions on remediation efforts (i.e., systems
approach). These two approaches are discussed in further detail below.
3D Model
EPA Region 5 officials used a gamma-ray imager (GeGI®) to characterize the AMS facility [1]. This device can
identify, localize, and quantify the distribution of gamma ray emitting materials by projecting a quantifiable gamma
ray radiation field onto an optical image [1]. This technology offers a quick and easy method for quickly
characterizing contaminated sites while simultaneously collecting spectral and spatial information. Figure 1 shows
an example image captured by the GeGI unit.
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USER GUIDE
DRAFT
Figure 1. GeGI Image
One deficiency of the GeGI results was that it projected its radiation field onto a 2D image as shown in Figure
1. Because the images lacked depth, the area and orientation of the hot spot could not be fully determined. This
was partially remediated by superimposing the gamma ray image onto a 3D surface, allowing the 3D model to
reconstruct the orientation of the surfaces. By using this approach, the area and extent of contamination can be
extrapolated and imported into the Hot Spot Calculator.
Systems Approach
Historically, Chemical, Biological, Radiological, and Nuclear (CBRN) incident response decision support tools
have solely focused on one particular problem or outcome, whether it is the identification of sampling locations
for characterization purposes, cost of decontamination, or the management of waste. A majority of these tools
ignore the impact a given decision (e.g., decontamination technology selection) may have on remediation efforts
as a whole. The ability to measure or predict the impact decisions or operations may have en masse, would greatly
enhance both decision making and remediation efforts. This concept of intricately tying together the various
processes and stages of remediation, in order to create a more encompassing system, is known as the systems
approach. As shown in Figure 2, as decisions are made, the resource demand may increase or decrease (typically
the; latter) in scale. With time, operationally driven decisions drive or tip the balance in favor of more resources.
This typically causes remediation to become resource intensive in terms of cost and time (e.g., a particular
decontamination method is costly, but is quicker). Hie systems approach seeks to balance the overall resource
demand by leveraging the system as a whole and predicting the most optimal outcome, which in return provides
greater insight and improves decision making. The HSC tool embodies this method by allowing the user to see
how their decisions impact other operations (e.g., decontamination vs. waste management) with regards to
resource demand (e.g., cost and time).
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USER GUIDE
DRAFT
Figure 2. Systems Thinking Approach for CBRN Incidents
Design
Hie HSC is composed entirely of a Microsoft Excel 2013 Workbook. The workbook is dynamic, in that it adjusts
its calculations to accommodate user-defined variables and is adaptable and scalable in order to accommodate
smaller or larger scenarios. The workbook consists of eight worksheets or tabs. These worksheets are arranged
in a manner that logically steps the user through the processes necessary to calculate the resource demands
associated with a selected decontamination technology These steps are further described below.
Home: the Home worksheet is the first screen the user sees once the workbook is launched. It contains
information about the tool, a text field to describe the active scenario, a results summary which contains
information aggregated across the workbook, a disclaimer, and assumptions.
Site Info: the Site worksheet describes the location and extent of contamination for an area of elevated activity
within a room or location on a remediation site. This sheet may be modified to accommodate smaller or larger
scenarios.
Decon Factors1: the Decon Factors worksheet provides a list of decontamination technologies that can be
prescribed within the Setup & Results sheet. The values in the Decon Factors sheet are collected from the ETA's
technology evaluation reports [2]. The technology name and parameters may be changed
1 Decontamination technologies (beyond the five available already available in the Decon Factors worksheet) should not be added unless you
are an advanced user of this tool and Excel. For expert assistance, please contact the developer of this tool.
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USER GUIDE
DRAFT
Miscellaneous Expenses: the Miscellaneous Expenses worksheet captures costs not specifically associated
with a decontamination technology and that are often hard to predict. This worksheet may be expanded to
accommodate additional expenses associated with decontamination and waste management activities.
Radionuclide Distribution: this worksheet uses an equation to describe the relative distribution of a given
radionuclide (Co-60 for AMS) in concrete2. Based on the distribution of the depth of the radionuclide, a removal
efficacy/depth is estimated [3]. This sheet should not be modified. However the distribution values can be
adjusted using the exploratory results from the initial decontamination work. For additional information please
contact the developer of this tool.
Radioactive Decay: the Radioactive Decay worksheet can be used to estimate the activity level of the
radioactive contaminant after a given period of time or how long it will take for a given initial activity of
radioactive material to decay to a specified activity level. This worksheet may be updated based on a given isotope
and half-life.
Setup & Results: the Setup & Results worksheet is used to prescribe a decontamination technology and specify
a targeted activity per room, location, and zone. HSC will then calculate the number of applications/passes
needed, specific to that decontamination technology's removal factor/depth, and other various resource
demands. This worksheet may be expanded to accommodate additional rooms, locations, and zones.
Charts: the Charts worksheet aggregates the data in the Setup & Results and displays it in a chart format. This
worksheet may be updated; however, experience with pivot charts may be useful.
Each worksheet within the workbook was designed to be printed and shared, with headers and footers that
reflect the names of the overall workbook and the individual worksheets for documentation purposes.
Since HSC was built using Excel, the workbook may be modified to account for larger or smaller scenarios by
simply dragging and expanding fields of interest. Chapter 3 will note whether or not a specified worksheet may
be expanded and how.
Assumptions
The HSC calculator is based on a number of assumptions derived through research results or professional
judgement. The selection of decontamination parameters available in the "Setup & Results" tab are somewhat
discretionary, but do reflect a potentially reasonable approach to decontamination. These estimates do not include
time and cost demands associated with personnel training, travel, location transition, Personal Protective
Equipment (PPE), or transportation. The penetration of radionuclides into the surfaces is based on results from
which may not precisely reflect the surfaces in the AMS building [3]. Furthermore, the prescribed
decontamination approach does not account for crevices, holes, or any other disturbance of the surface as this
may have enhanced the penetration of the contaminant into the concrete.
2 For the immediate purposes of this tool, only radionuclide distribution information specific to concrete was considered. Future versions of
the tool may include other surface types. Advanced users can reference the cited literature to specify exponential approximations that
describe additional surface types.
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Installation & Setup
Below you willfind step-by-step instructions to download and install HSC
T
1 his chapter explains how to install and set up HSC. Before installation, confirm that your system meets
or exceeds the recommended hardware and software requirements.
Note
Upon launching the workbook, Excel may ask you to update links. It is recommended that you
approve this request by pressing the "Update" button; otherwise some of the formulas may fail.
Minimum System and Software Requirements
This section provides the minimum system requirements and required software for HSC. Meeting the minimum
system requirements does not guarantee that HSC will operate as intended. Memory requirements are often
dependent on the number of rows being used in the workbook. Excel 2013 is currently limited to 1,048,576 rows
by 16,384 columns; however it is unlikely that this limitation will be met for the purposes of this workbook.
Table 1. Minimum System and Software Requirements
Reqi tired Software
Microsoft Office Excel 2013+
Processor
1 gigahertz (GHz) or faster x86- or x64-bit processor with SSE2 instruction set
RAM
1 gigabyte (GB) Random Access Memory (RAM) (32-bit); 2 gigabytes (GB) RAM
(64-bit)
Screen Resolution
1024 x 768 pixels
Operating System
Windows 7-10
Disk Space
3.0 gigabytes (GB) available
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USER GUIDE
Quick Start User Guide
A quick start guide for using the HSC Tool
,|1 his chapter provides the necessary steps to create a HSC scenario from beginning to end.
Note
The process of modeling gamma ray and 3D imagery will require the use of 3D modeling such as
Sketchup or Blender.
Combining Gamma Ray & 3D Blueprint imagery
The HSC uses a novel method of projecting contamination information onto a 3D surface. This section will step
the user through the process required for superimposing contamination information onto a 3D surface.
Before proceeding, it is recommended that you have already documented the dimensions of
the contaminated area and associated activity level using a gamma-ray imaging device.
1. Information regarding contamination the type, level, and extent of contamination can be derived
using a gamma-ray imaging device. The PHDS Co. Germanium Gamma-Ray Imager (GeGI) was
referenced in the development of this tool. A complete and thorough characterization of the site
should be conducted before using this tool.
2. Once the site has been characterized, the images taken by the imaging device can then be
manually imported into a 3D modeling program of choice (e.g., SketchUp). The building
footprint information will need to be imported into the 3D modeling software and the
walls/floors extruded to the appropriate height. Using the images as a reference, draw the
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USER GUIDE
DRAFT
contaminated area divided into 4 separate zones:, onto the impacted surfaces. Eigure 3 shows a
gamma-ray image (derived from GeGI) (left) that was converted to a 3D image (right). One's
judgement should be used when determining the orientation, size, and dimensions of a given
hotspot.
Figure 3. Comparison of GeGI image converted to a 3D image
3. Using the 3D modeling software, extract the area of each zone in mr. In Sketchup, this can be
done by using the "Select Tool" and right clicking on a zone of interest and selecting "Area" and
"Selection".
4. This process will need to be completed for each location and area of contamination
Home
The Home sheet is the first screen the user sees when the workbook is launched. It contains information
about the tool, a text field to describe the active scenario, a results summary which contains information
aggregated across the workbook, a disclaimer, and assumptions.
1. The purpose of the Home worksheet is to aggregate information pertaining to the scenario in an
easy to read format.
2. The only portion of the Home worksheet that should be modified is the "Scenario Description".
The remaining sections reference information stored elsewhere in the workbook. Changes to the
data or text can be made on the various workbook pages.
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USER GUIDE DRAFT
Site Info
The Site worksheet describes the location and extent of contamination for an area of elevated activity within a
room or location on a remediation site. This worksheet may be modified to accommodate smaller or larger
scenarios.
1. The Site Info worksheet uses a distribution method to estimate the level of activity across a given
contaminated area. The default percentages assigned to this table may be modified, but should not
total over 100%.
2. The room descriptor, location, and zone designations are specific to the contaminated area or area
of interest. They can be modified as necessary; however, it is highly recommended that rows be
deleted or inserted per the guidance described here.
3. To expand the Setup and Results table, you must first add the area and activity field. To do this,
select and right click the total row and select insert row, as shown in Figure 4. A new row will be
added.
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Figure 4. Adding Rows in Worksheet
4. You may add additional rows (i.e., rooms, locations or zones) by repeating the above process.
Once you have added the desired number of rows, you may now enter your area and activity
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USER GUIDE DRAFT
information. Note that the values shown in the "Area" column must be added and the total
entered in the "Location Total" column.
5. The area and contamination information is retrieved by projecting the gamma ray imagery onto
the 3D model, as described above. The activity is automatically calculated based on the
distribution of contamination as defined in Step 1.
6. Note that any changes made to the site info sheet may impact calculations throughout the
worksheet, including the results. An extensive review should be conducted to ensure formulas are
operating as intended. This is especially important when expanding the site info sheet.
Decon Factors
The Decon Factors worksheet provides a list of mechanical decontamination technologies that can later
be prescribed within the "Setup & Results" sheet. The technology name and parameters may be changed;
however, additional technologies (beyond the five slots) should not be added unless you are an advanced
Excel user.
1. The Decon Factors worksheet contains specific information related to decontamination
technologies. This information can be retrieved from literature or other sources.
2. The decontamination technology name and attributes highlighted in orange may be modified.
3. It is highly recommended that the units remain in their default value. You may add additional
technologies; however, the list should not exceed five technologies as the workbook will not
know where to reference this information later.
4. The reference for the default values is listed in Chapter Five of this report.
Miscellaneous Expenses
The Miscellaneous Expenses worksheet captures costs not specifically associated with a decontamination
technology. This worksheet may be expanded to accommodate additional expenses.
1. The default values and titles listed in the "Miscellaneous Expenses" worksheet can be modified to
reflect site specific needs and information. Caution should be taken to ensure that the
"Miscellaneous Expense Total" line is not removed since it is directly linked and referenced in the
Home worksheet. New rows can be inserted or the user may drag and drop the line further up or
down the worksheet. This will update the cell reference on the Home worksheet.
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USER GUIDE
DRAFT
Radionuclide Distribution
The Radionuclide Distribution worksheet uses an exponential approximation of the relative radionuclide
distribution to estimate the distribution of a given radionuclide in concrete. Based on the distribution of
the depth of the radionuclide, a removal efficacy/depth is estimated.
1. The cells highlighted in orange may be modified; however, this should only be done if you are
familiar with this topic as modifying the exponential factor will impact the required removal depth
per technology. The default factor was derived from NHSRC research on the fate and transport
of radiocesium, radiostrontium and radiocobalt on urban building materials [3].
2. The Setup and Results worksheet uses a subset of this equation to estimate the number of passes
needed based on a given decontamination technology.
3. A reference for the equation is listed in Chapter Five of this report
Radioactive Decay
The Radioactive Decay worksheet can be used to estimate the activity level of radioactive contaminant
left after a given period of time or how long it will take for a given initial activity of radioactive material to
decay to a specified final activity level. This worksheet may be updated based on a given isotope and half-
life.
1. The Radioactive Decay worksheet includes two functions; one to determine the remaining activity
level after a specified decay period and the other to determine the time required to achieve a
specified activity level. This worksheet is meant to function as a calculator/point of reference.
The fields highlighted in orange can be modified; based on the isotope of interest. The inputs are
used to calculate the time delay attribute located in the Home worksheet.
Setup & Results
The Setup & Results worksheet is used to define the decontamination technology and targeted activity
per room, location, and zone as well as the type of decontamination technology that will be applied. HSC
will then calculate the number of applications/passes needed, specific to that decontamination
technology's removal efficacy/depth, and other various resource demands. Aggregated results are
displayed at the bottom of the table and in the "Home worksheet".
1. There are four modifiable areas in the Setup & Results worksheet: Room, Decon Technology,
Targeted Activity, and the Additional Factors.
2. The Decon Technology column consists of a drop down menu where various types of
decontamination technologies (defined in the Decon Factors worksheet) can be selected. Once
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USER GUIDE DRAFT
the appropriate decontamination technology is selected, Excel will calculate the number of
applications/passes needed based on that technology's removal efficacy/depth and the
contaminant's estimated vertical penetration (via the radionuclide distribution tab). Using this
information, a required removal depth (m/m2) is estimated. The recommended removal
efficacy/depth is then compared to the technology's removal efficacy/depth and is rounded up to
a whole number. Based on this calculation, the number of applications/passes necessary to reach
an established target activity is estimated.
3. The remaining variables such as waste, waste activity, waste disposal cost, etc. are calculated
according to the number of applications/passes required per m2 of technology and amount of
material decontaminated/removed per application/pass. The totals of these variables can be
found at the bottom of the worksheet or on the Home worksheet.
4. To add more rows to represent rooms, locations, or zones, right click the total row and click
"Insert". To auto populate the cells, select the contents of the top filled row and drag down —
filling in the four rows. An example of this is shown in Figure 5.
0.00181
0.002
0.00148
0.002
0.00172
0.002
0.00187
0.002
0.00198
0.002
r\
0.11
0.159
Figure 5. Expanding Rows in the Worksheet
5. The worksheet may still require some aesthetic modifications; however, the formulas should still
be functional. This process can be repeated as many times as needed as long as the "Setup &
Results" worksheet exactly reflects the areas described in the "Site Info" worksheet. The totals
shown in the "Home worksheet" will automatically reflect the updated values.
Charts
The Charts worksheet aggregates the data located in the Setup & Results worksheet and displays it in a
chart format. Two different charts are created: 1) resource demands according to decontamination
technology; and 2) resource demands according to location.
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USER GUIDE DRAFT
1. The resource demands according to decontamination technology chart is essentially a pivot chart.
If any changes that are made to the "Setup & Results" worksheet (e.g., selecting a new
decontamination technology) the chart will need to be refreshed. To refresh the pivot chart, right
click on the chart and select "Refresh". If major modifications are made to the "Setup & Results"
worksheet, the pivot chart may need to be recreated.
2. The resource demand according to location is a simple table that aggregates information found in
the "Setup & Results" worksheet. This table should automatically update; however, if any major
modifications are made to the "Setup & Results" worksheet, the data range may need to be
updated.
This concludes the HSC user guide. If you have any questions, please email the point of
contact listed in Chapter 1.
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TROUBLESHOOTING
Troubleshooting
A troubleshooting guide
This chapter provides solutions to commonly found problems that users may encounter using the
HSC tool. It is recommended that you confirm software and hardware compatibility (information
found in Chapter 2 of this document) before continuing.
PROBLEM CAUSE REMEDY
Excel asks me to save
even if I have not made
any changes.
When I start the
workbook, Microsoft
Excel displays a warning
asking me to update the
links contained in the
workbook.
One of my cells reads as
"#DI.V/0"
A few links may have been
updated on startup without the
user's knowledge. This is typical
of Excel.
The workbook contains links to
other workbooks or files (called
source files), and when the source
files are changed, then the links in
workbook may display
information that is out of date
and therefore needs to be
updated.
You have likely deleted a
variable that that cell is trying to
use.
Unless you have made any
updates to the workbook, it is not
recommended that you save the
document.
Click the "Update" button
Review the worksheet for missing
information or start over from
scratch.
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BIBLIOGRAPHY
Chapter
Bibliography
A list of references
1. PHDS, Gamma-ray Imagingwith GeGI at the Advanced Medical Systems Site: Data Analysis and Report.
2015.
2. US EPA, Evaluation of Five Technologiesfor the Mechanical Removal ofRadiological Contamination from
Concrete Surfaces. 2011, U.S. Environmental Protection Agency, Washington, DC.
3. K. Maslova, I. Stepina, A. Konoplev, V. Popov, A. Gusarov, F. Pankratov, S.D. Lee, N. Il'icheva.,
Fate and transport of radiocesium, radiostrontium and radiocobalt on urban building materials. Journal of
Environmental Radioactivity, 2013.
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BIBLIOGRAPHY
U.S. Environmental Protection Agency
Homeland Security Research Program
Research Triangle Park, NC 27711
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United States
Environmental Protection
Agency
STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
search and Development (8101R)
Washington, DC 20460
Official Business
Penalty for Private Use
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