1. AS50 FRMAC Assessment Science Overview Part 2 Public Protection
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2. What questions might be asked?
Is a release extensive enough to warrant a protective action (shelter/evacuate and/or relocate)?
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3. What do you need to know? Default or modified Time Phase(s)
Which Pathways to include
What are the Dose Limits
Do you know Radionuclide inventory/activities/ratios
On the ground
In the air
Or both
Can you assume equilibrium?
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4. Where do you get your information?
FRMAC Defaults
Local Decision-makers
Regulatory Agencies
Intel
Models (NARAC, RASCAL)
Measurements (In-situ, Lab)
SWAG (update as more info becomes available)
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5. Public Protection Overview
What is a Dose Parameter?
Public Protection Dose Pathways
What is a Derived Response Level (DRL)?
How are DRLs used?
Public Protection Assumptions
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6. What is a Dose Parameter?
A dose from a radionuclide received by an individual over a time period from a particular pathway
The dose may be delivered via 4 primary pathways
Plume
Plume Inhalation
Plume Submersion
Ground
Inhalation of Resuspended materials
Groundshine
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7. How is a Dose Parameter used?
Dose Parameters are needed to calculate a Derived Response Levels (DRLs)
Dose Parameters indicate which pathway presents the greatest hazard
Decision makers can use this information to determine the most appropriate protective action
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8. What is a Derived Response Level (DRL)?
A level of radioactivity in an environmental medium that would be expected to produce a dose over a time period equal to its corresponding Protective Action Guide (PAG) value
DRLs are measureable quantities
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9. Public Protection DRLs
Deposition DRLs - The areal activity of a radionuclide at which the total dose from all radionuclides in a release would equal the PAG over the time period under consideration
Integrated Air DRLs - The integrated air activity of a radionuclide at which the total dose from all radionuclides in a release would equal the PAG over the time period under consideration
Dose Rate DRLs - The external dose rate from all radionuclides in a release that would produce a dose equal to the PAG over the time period under consideration
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10. How are DRLs used?
Public Protection DRLs are calculated, measureable quantities that correspond to a PAG value
Public Protection DRLs are used to generate contours on NARAC Dispersion Models to project areas where Protective Actions should be considered
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12. Public Protection Assumptions
Adult receptor, Whole Body dose
The receptor is outside and unprotected
The plume is in contact with the ground
Airborne noble gases are not deposited
Deposition is immediate
Deposition is assumed to be dry particulates with a Particle Size of micron AMAD
ICRP Recommended Lung Clearance Type
Daughter radionuclides are at equilibrium if t1/2 < ultimate parent and t1/2 < 1.5 y
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13. Public Protection Calculation Methods
In this section we will discuss methods for calculating:
Dose Parameters
Plume Pathways and related Dose Parameters
Ground Pathways and related Dose Parameters
Total Dose Parameter
Mixture Total Dose Parameter
DRLs
Deposition and Integrated-Air DRLs
Dose and Exposure Rate DRLs
Projected Public Dose
The DRLÃ represents the integrated air activity (Ã) (µCi•s/m3), of radionuclide i at which the total dose from all radionuclides in a release from the pathways included in the assessment would equal the Protective Action Guide (PAG) over the time phase under consideration.
The DRLDp represents the areal activity (µCi/m2), at a specific Evaluation Time (tn), of radionuclide i at which the total dose from all radionuclides in a release from the pathways included in the assessment would equal the Protective Action Guide (PAG) over the time phase under consideration.
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14. Major Dose Pathways From a Release
Plume Pathways
Submersion (γ)
Inhalation (α,β,γ)
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15. Plume Inhalation Dose Parameter
Plume Inhalation Pathway
The projected committed dose from the inhalation of plume-borne radionuclide i over the time phase is the Plume Inhalation Dose Parameter (Pl_InhDPi).
The Pl_InhDPi is calculated for each radionuclide present in the release, and includes the:
Inhalation Dose Coefficient (InhDC); mrem/μCi
Integrated Air Activity (Ã); μCi•s/m3
Light Exercise Breathing Rate (BRLE); m3/s
NOTE: We use the Light Exercise Breathing Rate because we are assuming the individual is actively seeking to exit the plume.
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16. Plume External Dose Parameter
Plume Submersion Pathway
The projected external dose from submersion from plume-borne radionuclide i over the time phase is the Plume External Dose Parameter (Pl_ExDPi).
The Pl_ExDPi is calculated for each radionuclide present in the release, and includes the:
Plume External Dose Coefficient (Pl_ExDC); mrem•m3/μCi•s
Integrated Air Activity (Ã); μCi•s/m3
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17. Major Dose Pathways From a Release
Inhalation of Resuspended
Material (α,β,γ)
Groundshine (γ)
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Ground Pathways

18. Deposition Inhalation Dose Parameter
Resuspension Inhalation Pathway
The projected committed dose from radionuclide i deposited on the ground from the inhalation of the resuspended fraction of the radionuclide over the time phase is the Deposition Inhalation Dose Parameter (Dp_InhDPi).
The Dp_InhDPi is calculated for each radionuclide present in the release, and includes the:
Inhalation Dose Coefficient (InhDC); mrem/μCi
Resuspension Parameter (KP); μCi•s/m3
Activity Averaged Breathing Rate (BRAA); m3/s
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19. Deposition External Dose Parameter
Groundshine Pathway
The projected external dose from groundshine from radionuclide i over the time phase is the Deposition External Dose Parameter (Dp_ExDPi).
The Dp_ExDPi is calculated for each radionuclide present in the release, and includes the:
Deposition External Dose Coefficient (Dp_ExDC); mrem•m2/μCi•s
Ground Roughness Factor (GRF); unitless
Weathering Parameter (WP); μCi•s/m2
Weathering Parameter is used to account for the integrated weathering of the radionuclide(s) over the time phase.
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20. Total Dose Parameter
The Total Dose Parameter (TDP) represents the dose from radionuclide i from the pathways included in the assessment and is obtained by summing the appropriate Dose Parameters from the following list:
the Plume Inhalation Dose Parameter (Pl_InhDP);
the Plume External Dose Parameter (Pl_ExDP);
the Deposition Inhalation Dose Parameter (Dp_InhDP); and
the Deposition External Dose Parameter (Dp_ExDP).
NOTE: The Sheltered Total Dose Parameter (TDPSh) is calculated by summing the Sheltered Dose Parameters from the selected Primary Dose Pathways.
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21. Mixture Total Dose Parameter
The Mixture Total Dose Parameter (MTDP) includes the dose contributions for all radionuclides in the mixture from each of the selected primary dose pathways, and is calculated by summing the TDPs for each radionuclide in the mixture.
𝑀𝑇𝐷 𝑃  𝑇𝑃 = 𝑖 𝑛 𝑇𝐷 𝑃 𝑖, 𝑇𝑃
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22. End of Pathway Discussion, Start of DRLs
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23. What are Derived Response Levels (DRLs)?
DRLs are levels of radioactivity in an environmental medium that would be expected to produce a dose equal to the corresponding PAG
DRLs are values which can be calculated and measured
DRLs are used to predict where protective actions should be considered
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24. Types of DRLs
FRMAC calculates three types of Public Protection DRLs to predict conditions where protective actions should be considered
DRLs can be calculated for:
Deposition Concentration (Dp)
Integrated Air Concentration (Ã)
Dose Rate
DRLs can be evaluated using any combination of pathways
DRLs may include dose from:
Plume Inhalation
Submersion
Inhalation of Resuspended Material
Groundshine
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25. Deposition and Integrated Air DRLs
The DRLDp represents the areal activity (µCi/m2), at a specific Evaluation Time (tn), of radionuclide i at which the total dose from all radionuclides in a release from the pathways included in the assessment would equal the Protective Action Guide (PAG) over the time phase under consideration
The DRLÃ represents the integrated air activity (µCi•s/m3), of radionuclide i at which the total dose from all radionuclides in a release from the pathways included in the assessment would equal the Protective Action Guide (PAG) over the time phase under consideration
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26. Deposition and Integrated Air DRLs
Compare the dose from a mixture to the PAG to calculate DRLs
The MTDP is the projected dose over the time phase from an entire mixture of radionuclides for all dose pathways
We are calculating the amount of a radionuclide (the DRL) that would cause the entire mixture to produce a given dose (the PAG) over the time phase
For an integrated air activity, this concept can be described mathematically as:
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27. Deposition and Integrated Air DRLs
Solving this equation for the DRL:
Note: For air evaluations, there is no need to account for decay or weathering because an integrated sample is used and weathering does not affect air samples.
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28. Deposition and Integrated Air DRLs
Similarly, for an areal (deposition) activity, at a given Evaluation Time (tn):
Note: For deposition evaluations, it is necessary to correct the areal activity of each radionuclide for decay and weathering.
Weathering FACTOR is used in this formula to account for the weathering & decay that has occurred since the time of deposition.
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29. Deposition and Integrated Air DRLs
Correcting for decay and weathering.
The amount of radioactive material deposited on the ground at the start of the Time Phase is used to calculate the MTDP over the Time Phase (The effects of decay and weathering are included in that calculation)
Since we want to be able to use measurements taken at any time, we need to add the effects of decay and weathering to the DRL calculation
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30. Deposition and Integrated Air DRLs
Why do we correct for decay and weathering?
Deposition and Dose Rate DRLs are calculated for a given Evaluation Time (tn)
The Evaluation Time is the time that a measurement is going to be (or was) taken
By calculating the DRL for that time, we know what measurement value would correspond to a dose over a time phase equal to the PAG
A measurement BELOW the DRL indicates that the dose in the area where the measurement was made would likely be BELOW the PAG
A measurement ABOVE the DRL indicates that the dose in the area where the measurement was made would likely be ABOVE the PAG
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31. Dose Rate DRLs
The Dose Rate DRLs (DRLDR) represents the external dose rate (mrem/hr, measured at 1 m above the ground) at a specific Evaluation Time (tn), from all radionuclides in a release that would produce a dose equal to the Protective Action Guide (PAG) over the time phase under consideration
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32. Dose Rate DRLs
The external dose rate (mrem/hr) from a deposited mixture of radioactive material at a given time (tn) is represented by the Deposition Mixture External Dose Factor (Dp_MExDF)
The Dp_MExDF is calculated by summing the contribution to external dose from each radionuclide present in the release, and includes:
Weathering Factor at time tn (WFtn); unitless
Ground Roughness Factor (GRF); unitless
Areal Activity of each radionuclide in the mixture (Dpi); μCi/m2
Deposition External Dose Coefficient for each radionuclide (Dp_ExDCi); mrem•m2/μCi•hr
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33. Dose Rate DRLs
The Dp_MExDF is the measured dose rate at a given time from the deposited radionuclide mixture
The MTDP is the projected dose from the radionuclide mixture over a specified time phase
Need to calculate the dose rate (the DRL) that would cause the entire mixture to produce a given dose (the PAG)
This can be described mathematically as:
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34. Dose and Exposure Rate DRLs
Solving this equation for the DRL
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35. Projected Public Dose
Calculates the projected dose received by members of the public from a release of radioactive material over a specified time phase
The dose can be calculated for any combination of pathways
Projected Public Dose is calculated using Radionuclide Mixture Sample Data
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36. Projected Public Dose
Calculating the PPD using Radionuclide Mixture data:
To calculate the PPD for a given time phase:
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37. Using Turbo FRMAC Public Protection Pathways
Will this released radioactive material result in a dose to a member of the public that exceeds the PAG?
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38. Assume the following Mixture
Setting the Stage
The Governor wants to know if he has to order a Relocation for his population
Calculate 1st Year DRL values based on Ground Deposition
Assume the following Mixture
Radionuclide
Activity per Area
(µCi/m2)
60Co 2
148Gd 1
90Sr 3
90Ya
a 90Y included as a daughter in equilibrium
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39. Open Turbo FRMAC
Select New Calculation
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40. Select New Calculation
Select Public Protection, then Derived Response Level, then Blank
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41. Name and Describe Calculation
Click on Name and Description Button
Type in a Name and Description for the calculation
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42. Verify Time Phases and Evaluation Time
Click on Time Settings Button
Verify Time Phases, Evaluation Time and Pathways are correct
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43. Build Radionuclide Mixture
Click on Radionuclide Mixture Button
Click on Search and begin to populate Radionuclides
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44. Build Radionuclide Mixture
Enter each Radionuclide in the mix and enter the Activity Concentration
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45. Run Calculation
Click the Deposition button
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46. Deposition DRL Created
Final Results displayed
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47. Dose Parameters
Find the Dose Parameter button at the top/center of the ribbon
Click the Dose Parameter button to open the listed Dose Parameters
for each radionuclide and each Time Phase
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48. Dose Parameters
Select First Year Dose Parameter button Dose Parameter panel comes into view
Dose Parameters indicate dose contribution from each radionuclide
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49. Dose Rate DRL Select Dose and Exposure - Final Results Displayed
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50. Integrated Air DRL Created
Select Integrated Air - Final Results Displayed
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51. Data Products
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52. Assume the same Mixture
Setting the Stage
What is the actual 1st year dose to a member of the public?
Calculate a 1st year Projected Public Dose
Assume the same Mixture
Radionuclide
Activity per Area
(µCi/m2)
60Co 2
148Gd 1
90Sr 3
90Ya
a 90Y included as a daughter in equilibrium
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53. Start a New Calculation
Projected Public Dose
Start a New Calculation
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54. Select Projected Public Dose Calculation
Select Public Protection, then Projected Public Dose, then Blank
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55. Name and Describe Calculation
Click on Name and Description Button
Type in a Name and Description for the calculation
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56. Verify Time Phases Click on Time Settings Button
Verify Time Phases and Pathways are correct
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57. Build Radionuclide Mixture
Click on Radionuclide Mixture Button
Click on Search and begin to populate Radionuclides
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58. Build Radionuclide Mixture
Enter each Radionuclide in the mix and enter the Activity Concentration
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59. Run Calculation
Click the Projected Public Dose button
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60. New Projected Public Dose Created
Final Results displayed
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61. Contact Information
Lainy Cochran
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62. Questions?
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