Letter Report

**VERIFICATION AND BENCHMARKING of the MILDOS-AREA CODE**

Prepared by

S. Kamboj, D.J. LePoire, T. Klett, and S.Y. Chen

Environmental Science Division

Argonne National Laboratory

Submitted to

Adam Schwartzman

Office of Nuclear Regulatory Research

Letter Report for NRC Project N6645

October 31, 2008

CONTENTS

ACRONYMS USED IN THIS REPORT 5

1 INTRODUCTION 6

2 Internal CheckING of MILDOS-AREA Code Calculations 7

2.1 CHI/Q Calculations 7

2.2 Particulate Release Rate Calculations 9

2.3 Ground Deposition 10

2.4 Air Concentration 11

2.5 Inhalation Pathway Dose 12

2.6 External Pathway Dose 13

2.7 Ingestion Pathway Doses 15

3 COMPARISON WITH RESRAD-OFFSITE 23

3.1 Chi/Q Comparison 23

3.2 Release Rate Comparison 24

3.3 Air Inhalation Pathway Dose Calculations 26

3.4 Ground Deposition - Surface Soil Concentrations at Offsite 27
Locations

3.5 External Pathway Dose Calculations 28

3.6 Plant Concentration Calculations 29

3.7 Meat and Milk Concentration Calculations 31

3.8 Ingestion Pathway Dose Calculations 32

3.9 Main Differences in MILDOS-AREA and RESRAD-OFFSITE 34

4 Verification of the Source Term Derivation and Integration of the
in-situ leaching SourceS with THE MILDOS-Area code 36

4.1 Verification of the ISL Source Term Derivation 37

4.1.1 Common ISL Facility Common Input Parameters 37

4.1.2 New Well Field --- ^222^Rn Release Rate and Average\
Flux Calculations 37

4.1.3 Yellow Cake Drying and Packaging 38

4.1.4 Restoration Well Field 39

4.1.5 Production Well Field 40

4.1.6 Land Application Area 42

4.2 Dose Comparison for Different ISL Source Types with MILDOS-Area
Source 46

5 CONCLUSIONS 50

6 REFERENCES 51

**TABLES**

2.1 Calculated Vertical-Dispersion Coefficient 8

2.2 Calculated CHI/Q Compared with CHI/Q from MILDOS-AREA Code Report 8

2.3 Comparison of Calculated and Reported CHI/Q at Different Receptor
Distances 8

2.4 Resuspension Rates for Different Wind Speeds 10

2.5 Comparison of Calculated and Reported Particulate Release Rates from
Different Contaminated Areas 10

2.6 Comparison of Calculated and Reported Ground Depositions at
Different Receptor Distances 11

2.7 Comparison of Calculated and Reported Total Air Concentrations at
Different Receptor Distances 12

2.8 Comparison of Inhalation Pathway Dose at Different Receptor
Locations 13

2.9 Comparison of Air Submersion Pathway Doses at Different Receptor
Locations 14

2.10 Comparison of Direct External Exposure Pathway Doses at\
Different Receptor Locations 15

2.11 Radionuclide Concentrations in Edible Above-Ground Vegetables 17

2.12 Radionuclide Concentrations in Potatoes 17

2.13 Radionuclide Concentrations in Edible Below-Ground Vegetables 18

2.14 Radionuclide Concentrations in Pasture Grass 18

2.15 Radionuclide Concentrations in Hay 18

2.16 Radionuclide Concentrations in Meat 19

2.17 Radionuclide Concentrations in Milk 19

2.18 Plant Ingestion Pathway Dose Comparison at Different Receptor
Locations 21

2.19 Meat Ingestion Pathway Dose Comparison at Different Receptor
Locations 22

2.20 Milk Ingestion Pathway Dose Comparison at Different Receptor
Locations 22

3.1 CHI/Q Comparison for Point Source 25

3.2 CHI/Q Comparison for Area Source 25

3.3 Air Concentration Comparison 26

3.4 Inhalation Pathway Dose Comparison 27

3.5 Ground Deposition Comparison 28

3.6 External Pathway Dose Comparison 29

3.7 Default Parameter Values in the MILDOS-AREA and RESRAD-OFFSITE Codes
for Plant Concentration Calculations 30

3.8 Plant Concentration Comparison 30

3.9 Default Parameter Values in the MILDOS-AREA and RESRAD-OFFSITE Codes
for Meat and Milk Concentration Calculations 31

3.10 Comparison of Meat and Milk Concentrations 32

3.11 Default Parameters for Ingestion Pathways in the MILDOS-AREA and
RESRAD-OFFSITE Codes for an Adult Member of the Public 33

3.12 Comparison of Ingestion Pathway Doses 33

4.1 Comparison of Source Release Terms for Different ISL Source Types 46

4.2 Dose Comparisons for New Well Field 47

4.3 Dose Comparisons for Yellow Cake Drying and Packaging Source 47

4.4 Dose Comparisons for Restoration Well Field Source 48

4.5 Dose Comparisons for Production Well Field Source 48

4.6 Dose Comparisons for Land Application Area Source 49

**ACRONYMS USED IN THIS REPORT**

ALC allowable concentration

DCF dose conversion factor

ISL in-situ leaching

NRC U.S. Nuclear Regulatory Commission

**1 INTRODUCTION**

The MILDOS code was developed by U.S. Nuclear Regulatory Commission
(NRC) staff with support from Pacific Northwest Laboratory in the early
1980s and was published in NUREG/CR-2011 (Strenge and Bander 1981). In
1989 the MILDOS code was replaced with a new code, MILDOS-AREA, by
Argonne National Laboratory (Yuan et al. 1989). In 1997 MILDOS-AREA was
updated for the NRC to incorporate an in-situ leaching (ISL) method in
uranium recovery (Faillace et al. 1997). The code was issued as a beta
version for public use and comment in 1999.

In June 2003, NUREG-1569 (NRC 2003) was issued. Appendix D of NUREG-1569
identified MILDOS-AREA as the acceptable methodology for estimating the
radiological impacts of airborne emissions from radioisotopes of the
uranium-238 series. The beta version of the code required updating and
verification for proper use in this role.

This report describes the actions and presents the results of the
verification and benchmarking of the MILDOS-AREA code. The limited-scope
verification was done by comparing spreadsheet calculation results with
MILDOS-AREA-generated reports.

The following aspects of the code were addressed:

-   Internal checking of a set of the MILDOS-AREA code calculations,

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-   A limited comparison of the MILDOS-AREA code with the air dispersion
    component of the RESRAD-OFFSITE code, and

-   Verification of the source derivation for ISL sources and the ISL
    source's integration with the MILDOS-AREA code.

Section 2 describes the internal checking of MILDOS-AREA code
calculations. The calculations for CHI/Q, particulate release rates,
ground deposition, air concentration, and pathway doses are verified.
Section 3 is a limited comparison of the MILDOS-AREA code with the
RESRAD-OFFSITE code. It also lists the main conceptual differences
between the two codes. Section 4 verifies the source term derivation for
different ISL source types, as well as the ISL source's integration with
the MILDOS-AREA code.

**2 Internal CheckING of MILDOS-AREA Code Calculations**$$

Internal checking consisted of comparing a few simple case results from
the MILDOS-AREA software with the spreadsheet calculations based on the
documented equations in the software manual. The spreadsheet
calculations were performed for CHI/Q, particulate release rates, ground
deposition, air concentration, inhalation pathway dose, external
exposure pathway dose, and ingestion pathway dose. The scenario included
a ground-level point source continually releasing 1 mCi/yr of ^238^U
over five years. The receptor was located at ground level at various
distances downwind (wind speed: 10 mph). For the wind-blown-release
scenarios, the release was from areas contaminated at 1 pCi/g of ^238^U,
^230^Th, ^226^Ra, and ^210^Pb under various wind speeds.

**2.1 CHI/Q CALCULATIONS**

The CHI/Q for a sector-averaged downwind Gaussian plume dispersion from
a ground level release is given by Equation 15c in Yuan et al. 1989
under certain conditions

$$\frac{\text{CHI}}{Q} = \frac{1}{\overset{}{u(\frac{\pi x}{8})\sigma_{z}\sqrt{\frac{\pi}{2}}}}$$

where:

*u* = average wind speed,

*x* = downward distance, and

$\sigma_{z}$= vertical dispersion coefficient.

The vertical-dispersion coefficient for the ground-level release is
given by:

$$\sigma_{z} = \text{Ax}^{B} + C$$

where *A*, *B*, and *C* are constants (see Table 2.1 in Yuan et al.
1989) for each stability class and for the three ranges of the downwind
distance.

The concentration in the plume is depleted by the dry deposition, wet
deposition, and radioactive decay processes. Only dry deposition is
considered a significant deposition process in the plume concentration
calculations for the MILDOS-AREA code (Yuan et al. 1989). The decrease
in source strength is calculated using Equation 18 in Yuan et al. 1989.

Table 2.1 shows the calculated vertical-dispersion coefficient for
different stability classes (classes A--F). The receptor was located
70.7 m downwind from the release point. Table 2.2 lists the calculated
CHI/Q and compares them with the CHI/Q in the MILDOS-AREA code report.
The differences were less than 3%. Table 2.3 lists the calculated CHI/Q
at different receptor locations and compares them with the CHI/Q in the
MILDOS-AREA code report. The differences were less than 5%.

  --------------------- ------------- ------- ------------ --- ------------ ------------- ---------- ------------ ------------
  **TABLE 2.1                                                                                                     
  Calculated                                                                                                      
  Vertical-Dispersion                                                                                             
  Coefficient**                                                                                                   

  Stability class       A             B                    C                *σ~z\ ~*(m)                           

  Class A               0.192         0.936                0                1.03E+01                              

  Class B               0.156         0.922                0                7.91E+00                              

  Class C               0.116         0.905                0                5.47E+00                              

  Class D               0.079         0.881                0                3.37E+00                              

  Class E               0.063         0.871                0                2.57E+00                              

  Class F               0.053         0.814                0                1.70E+00                              

  **TABLE 2.2                                                                                                     
  Calculated CHI/Q                                                                                                
  Compared with CHI/Q                                                                                             
  from MILDOS-AREA Code                                                                                           
  Report**                                                                                                        

  Stability class       *σ~z\ ~*(m)           Source           CHI/Q                                              
                                              strength         (pCi/m^3^                                          
                                              decrease due     per pCi/sec)                                       
                                              to dry                                                              
                                              deposition                                                          

                                                               Calculated                 Reported                Reported/\
                                                                                                                  calculated
                                                                                                                  ratio

  Class A               1.03E+01              9.45E-01         5.87E-04                   5.73E-04                9.76E-01

  Class B               7.91E+00              9.30E-01         7.55E-04                   7.39E-04                9.79E-01

  Class C               5.47E+00              9.04E-01         1.06E-03                   1.05E-03                9.85E-01

  Class D               3.37E+00              8.55E-01         1.63E-03                   1.63E-03                9.96E-01

  Class E               2.57E+00              8.17E-01         2.04E-03                   2.05E-03                1.00E+00

  Class F               1.70E+00              7.60E-01         2.88E-03                   2.94E-03                1.02E+00
  --------------------- ------------- ------- ------------ --- ------------ ------------- ---------- ------------ ------------

  ------------- ---------------- ---------- ---------------- ---------- ---------------- ---------- ---------------- ---------- ---------------- ----------
  **TABLE 2.3                                                                                                                                    
  Comparison of                                                                                                                                  
  Calculated                                                                                                                                     
  and Reported                                                                                                                                   
  CHI/Q at                                                                                                                                       
  Different                                                                                                                                      
  Receptor                                                                                                                                       
  Distances**                                                                                                                                    

  Stability     CHI/Q (pCi/m^3^                                                                                                                  
  class         per pCi/sec) at                                                                                                                  
                different                                                                                                                        
                receptor                                                                                                                         
                distances from                                                                                                                   
                the release                                                                                                                      
                point                                                                                                                            

                [42.4                       [56.6                       [70.7                       [99.0                       [141.4           
                m]{.underline}              m]{.underline}              m]{.underline}              m]{.underline}              m]{.underline}   

                Calc.            Report.    Calc.            Report.    Calc.            Report.    Calc.            Report.    Calc.            Report.

  Class A       1.59E-03         1.52E-03   9.07E-04         8.77E-04   5.87E-04         5.73E-04   3.04E-04         3.00E-04   1.52E-04         1.56E-04

  Class B       2.04E-03         1.94E-03   1.16E-03         1.13E-03   7.55E-04         7.39E-04   3.93E-04         3.89E-04   1.96E-04         2.02E-04

  Class C       2.85E-03         2.73E-03   1.63E-03         1.59E-03   1.06E-03         1.05E-03   5.53E-04         5.52E-04   2.77E-04         2.78E-04

  Class D       4.37E-03         4.23E-03   2.51E-03         2.47E-03   1.63E-03         1.63E-03   8.53E-04         8.61E-04   4.28E-04         4.27E-04

  Class E       5.47E-03         5.34E-03   3.14E-03         3.12E-03   2.04E-03         2.05E-03   1.07E-03         1.09E-03   5.34E-04         5.45E-04

  Class F       7.61E-03         7.51E-03   4.40E-03         4.43E-03   2.88E-03         2.94E-03   1.51E-03         1.57E-03   7.64E-04         7.98E-04
  ------------- ---------------- ---------- ---------------- ---------- ---------------- ---------- ---------------- ---------- ---------------- ----------

**2.2 PARTICULATE RELEASE RATE CALCULATIONS**

Windblown particle emissions in the MILDOS-AREA code is calculated using
Equation 2 in NUREG/CR-4088 (Hartley et al.1985), given as:

$$E_{w} = \frac{3\text{.}\text{156} \times \text{10}^{7}}{0\text{.}5} \times \sum_{s}^{}{(R_{s}F_{s})}$$

where:

*E~w~* = annual dust loss per unit area, g/(m^2^.yr),

3.156E+07 = number of seconds per year,

0.5 = fraction of total dust loss for particles \<20 μm diameter,

*R~s~* = resuspension rate for wind speed group *s*, g/(m^2^.sec), and

*F~s~* = annual average frequency of occurrence of wind speed group *s*.

The particle release rate, *S*, is calculated using Equation 3 in
Hartley et al. (1985), as:

$$S = E_{w}\text{ACfN}(1 - R)$$

where:

*A* = exposed surface area, m^2^,

*C* = radionuclide concentration, pCi/g,

*f* = fraction of a particular radionuclide present,

*N* = activity enrichment ratio of concentration in dust/bulk material,
and

*R* = control factor depending on the degree of control applied.

Table 2.4 lists the resuspension rates (see Table 1 of Hartley et al.
1985) and annual average frequencies of occurrence of wind speeds used
in this comparison. The default value in the MILDOS-AREA code for
activity enrichment ratio is 2.5 (see page 14 of Hartley et al. 1985).
The particle release rates for various square areas of contamination are
compared in Table 2.5 (assuming no control and contamination at 1 pCi/g
of ^238^U, ^230^Th, ^226^Ra, and ^210^Pb). The difference between the
calculated values and the values in the MILDOS-AREA report was less than
0.03%.

  ----------------- ------------------ --------------- ---------------- ---
  **TABLE 2.4                                                           
  Resuspension                                                          
  Rates for                                                             
  Different Wind                                                        
  Speeds**                                                              

  Average wind      Resuspension rate  Frequency of    *F~s~*\**R~s~*   
  speed (mph)       (*R~s~*)           occurrence                       
                    \[g/(m^2^.sec)\]   (*F~s~*)                         

  1.5               0                  0.1667          0                

  5.5               0                  0.1667          0                

  10                3.92E-07           0.1667          6.53E-08         

  15.5              9.68E-06           0.1667          1.61E-06         

  21.5              5.71E-05           0.1667          9.52E-06         

  28                2.08E-04           0.1667          3.47E-05         
  ----------------- ------------------ --------------- ---------------- ---

  -------------- ------------------- ------------------- -----------------
  **TABLE 2.5                                            
  Comparison of                                          
  Calculated and                                         
  Reported                                               
  Particulate                                            
  Release Rates                                          
  from Different                                         
  Contaminated                                           
  Areas**                                                

                 Particulate release                     
                 rates (Ci/yr)                           

  Area (m^2^)    Calculated          Reported            Reported/\
                                                         calculated ratio

  0.01           7.24E-11            7.22E-11            9.97E-01

  0.1            7.24E-10            7.22E-10            9.97E-01

  1              7.24E-09            7.22E-09            9.97E-01

  10             7.24E-08            7.22E-08            9.97E-01

  100            7.24E-07            7.22E-07            9.97E-01

  1,000          7.24E-06            7.22E-06            9.97E-01

  10,000         7.24E-05            7.22E-05            9.97E-01

  100,000        7.24E-04            7.22E-04            9.97E-01
  -------------- ------------------- ------------------- -----------------

**2.3 GROUND DEPOSITION**

In MILDOS-AREA code ground concentration due to constant deposition over
time *t* in surface soil is calculated using Equation 2.3-1 from
NUREG/CR-2011 (Strenge and Bander 1981), given as:

$$X_{g}(t) = \frac{1 - \text{exp}\lbrack - (\lambda + \lambda_{e})t}{\lambda + \lambda_{e}}\sum_{s}^{}{x(s)V_{d}(s)}$$

Where:

*X~g~(t)* = ground surface concentration at time *t*,

*t* = time interval over which deposition has occurred, sec,

$\lambda$= radioactive decay constant, sec^-1^,

$\lambda_{e}$= rate constant for environment loss, sec^-1^,

*x(s)* = direct annual average air concentration for particle size
fraction *s*, pCi/m^3^, and

*V~d~* = deposition velocity of particle size fraction *s*, m/sec.

The default value of deposition velocity for ^238^U in the MILDOS-AREA
code is 0.01 m/sec for a particle size of 3 μm (the particle size used
in this comparison). The environmental losses in the code are described
by a rate constant corresponding to a 50-year half-time. The direct
annual average air concentration for this comparison was calculated from
the calculated CHI/Q values, initial point source release of 1 mCi/yr of
^238^U, and the unit conversion factor from second to year.

Table 2.6 lists the calculated ground depositions using the above
equation at five different receptor distances from the point source
release. The calculations were done for all stability classes at 10 mph
wind speed. The calculated values were compared with the values in the
MILDOS-AREA code report. The differences were less than 5% in all cases,
and in most cases the results were within 2%.

<table style="width:100%;">
<colgroup>
<col style="width: 7%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="11"><blockquote>
<p><strong>TABLE 2.6 Comparison of Calculated and Reported Ground
Depositions at Different Receptor Distances</strong></p>
</blockquote></td>
</tr>
<tr class="even">
<td rowspan="3">Stability class</td>
<td colspan="10">Ground concentrations (pCi/m<sup>2</sup>) at different
receptor distances (in x, y, and z coordinates) from the release
point</td>
</tr>
<tr class="odd">
<td colspan="2"><u>30 m, 30 m, 0 m</u></td>
<td colspan="2"><u>40 m, 40 m, 0 m</u></td>
<td colspan="2"><u>50 m, 50 m, 0 m</u></td>
<td colspan="2"><u>70 m, 70 m, 0 m</u></td>
<td colspan="2"><u>100 m, 100 m, 0 m</u></td>
</tr>
<tr class="even">
<td>Calc.</td>
<td>Report.</td>
<td>Calc.</td>
<td>Report.</td>
<td>Calc.</td>
<td>Report.</td>
<td>Calc.</td>
<td>Report.</td>
<td>Calc.</td>
<td>Report.</td>
</tr>
<tr class="odd">
<td>Class A</td>
<td>7.68E+04</td>
<td>7.32E+04</td>
<td>4.38E+04</td>
<td>4.24E+04</td>
<td>2.84E+04</td>
<td>2.77E+04</td>
<td>1.47E+04</td>
<td>1.45E+04</td>
<td>7.33E+03</td>
<td>7.55E+03</td>
</tr>
<tr class="even">
<td>Class B</td>
<td>9.84E+04</td>
<td>9.39E+04</td>
<td>5.63E+04</td>
<td>5.46E+04</td>
<td>3.65E+04</td>
<td>3.57E+04</td>
<td>1.90E+04</td>
<td>1.88E+04</td>
<td>9.49E+03</td>
<td>9.74E+03</td>
</tr>
<tr class="odd">
<td>Class C</td>
<td>1.38E+05</td>
<td>1.32E+05</td>
<td>7.89E+04</td>
<td>7.69E+04</td>
<td>5.12E+04</td>
<td>5.05E+04</td>
<td>2.67E+04</td>
<td>2.66E+04</td>
<td>1.34E+04</td>
<td>1.34E+04</td>
</tr>
<tr class="even">
<td>Class D</td>
<td>2.11E+05</td>
<td>2.04E+05</td>
<td>1.21E+05</td>
<td>1.19E+05</td>
<td>7.88E+04</td>
<td>7.85E+04</td>
<td>4.12E+04</td>
<td>4.16E+04</td>
<td>2.07E+04</td>
<td>2.06E+04</td>
</tr>
<tr class="odd">
<td>Class E</td>
<td>2.64E+05</td>
<td>2.58E+05</td>
<td>1.52E+05</td>
<td>1.51E+05</td>
<td>9.86E+04</td>
<td>9.91E+04</td>
<td>5.15E+04</td>
<td>5.25E+04</td>
<td>2.58E+04</td>
<td>2.63E+04</td>
</tr>
<tr class="even">
<td>Class F</td>
<td>3.67E+05</td>
<td>3.63E+05</td>
<td>2.13E+05</td>
<td>2.14E+05</td>
<td>1.39E+05</td>
<td>1.42E+05</td>
<td>7.31E+04</td>
<td>7.58E+04</td>
<td>3.69E+04</td>
<td>3.86E+04</td>
</tr>
</tbody>
</table>

**2.4 AIR CONCENTRATION**

The total air concentration is calculated as the sum of the direct air
concentrations from all sources and the resuspended air concentration
from ground deposition. The resuspended component would increase with
the time interval over which deposition occurs. The resuspended air
concentration is calculated using Equation 2.2-26 from Strenge and
Bander (1981) for time interval \>1.82 year, given as:

$X_{R}(s) = X(s) \times V_{d} \times 3\text{.}\text{156}\text{E-}\text{07}\left\{ \text{10}^{- 5}\left\lbrack \frac{1 - \text{exp}\left\lbrack - \left( \lambda_{i}^{} + \lambda_{R} \right)\left( 1\text{.}\text{82} \right) \right\rbrack}{\left( \lambda_{i}^{} + \lambda_{R} \right)} \right\rbrack + \text{10}^{- 9}\left\lbrack \frac{\text{exp}\left( - 1\text{.}\text{82}\lambda_{i}^{} \right) - \text{exp}\left( - \lambda_{i}^{}t \right)}{\lambda_{i}^{}} \right\rbrack \right\}$where:

*10^-5^* = initial resuspension rate, m^-1^,

*10^-9^* = final resuspension rate (after 1.82 years), m^-1^,

*X(s)* = direct air concentration, pCi/m^3^,

*V~d~* = deposition velocity, m/sec,

$\lambda_{i}^{}$= the effective removal constant for radionuclide *i* on
soil, yr^-1^, and

$\lambda_{R}$= assumed decay constant of resuspension factor, 5.06
yr^-1^.

For long-lived ^238^U, it is assumed that the effective removal constant
is equal to the environmental loss constant. It is further assumed that
the deposition velocity for the selected particle size is 0.01 m/sec.
Using the above equation, the resuspended air concentration was
calculated at various potential receptor distances.

Table 2.7 lists the calculated total air concentration using the
resuspended air concentrations and direct air concentrations at five
different receptor distances. The calculations were done for all
stability classes for 10 mph wind speed and compared with the values in
the MILDOS-AREA code report. The differences were less than 7% in all
cases, and in most cases the results were within 3%.

  ---------------- ---------------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
  **TABLE 2.7                                                                                                               
  Comparison of                                                                                                             
  Calculated and                                                                                                            
  Reported Total                                                                                                            
  Air                                                                                                                       
  Concentrations                                                                                                            
  at Different                                                                                                              
  Receptor                                                                                                                  
  Distances**                                                                                                               

  Stability class  Total air                                                                                                
                   concentrations                                                                                           
                   (pCi/m^3^) at                                                                                            
                   different                                                                                                
                   receptor                                                                                                 
                   distances (in x,                                                                                         
                   y, and z                                                                                                 
                   coordinates)                                                                                             
                   from the release                                                                                         
                   point                                                                                                    

                   30 m, 30 m, 0 m             40 m, 40              50 m, 50              70 m, 70              100 m, 100 
                                               m, 0 m                m, 0 m                m, 0 m                m, 0 m     

                   Calc.            Report.    Calc.      Report.    Calc.      Report.    Calc.      Report.    Calc.      Report.

  Class A          8.33E-02         7.79E-02   4.75E-02   4.51E-02   3.08E-02   2.95E-02   1.60E-02   1.54E-02   7.95E-03   8.03E-03

  Class B          1.07E-01         1.00E-01   6.10E-02   5.81E-02   3.96E-02   3.80E-02   2.06E-02   2.00E-02   1.03E-02   1.04E-02

  Class C          1.49E-01         1.41E-01   8.56E-02   8.19E-02   5.56E-02   5.37E-02   2.90E-02   2.84E-02   1.45E-02   1.43E-02

  Class D          2.29E-01         2.17E-01   1.31E-01   1.27E-01   8.55E-02   8.35E-02   4.47E-02   4.42E-02   2.24E-02   2.20E-02

  Class E          2.87E-01         2.75E-01   1.65E-01   1.61E-01   1.07E-01   1.06E-01   5.58E-02   5.58E-02   2.80E-02   2.80E-02

  Class F          3.99E-01         3.86E-01   2.31E-01   2.28E-01   1.51E-01   1.51E-01   7.93E-02   8.07E-02   4.00E-02   4.10E-02
  ---------------- ---------------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------

**2.5 INHALATION PATHWAY DOSE**

Inhalation pathway dose for a given radionuclide is calculated using
Equation 2.4-1 in Strenge and Bander (1981), given as:

$$D_{l}(\text{inh}) = \sum_{s}^{}{\sum_{l}^{}{x(s)\text{DCF}_{\text{ls}}(\text{inh})}}$$

where:

*D~l~(inh)* = inhalation dose to organ *l*, mrem/yr,

*x(s)* = total air concentration for particle size *s*, pCi/m^3^, and

*DCF~ls~(inh)* = inhalation dose conversion factor for organ *l* for
particle size *s*, mrem/yr per pCi/m^3^.

The inhalation dose conversion factors for ^238^U, ^234^U, ^230^Th,
^226^Ra, ^210^Pb, and ^210^Po in the MILDOS-AREA code are provided as a
function of particle size and organ. Pathway dose does not depend on the
selection of stability class. The inhalation pathway doses were
calculated using the above equation and compared with the MILDOS-AREA
report. The comparison was only done for one stability class (Stability
Class A) for 1 mCi ^238^U point source release at ground level. The
committed effective dose equivalent for an adult member of the public
was compared.

Table 2.8 lists the calculated inhalation pathway doses for an adult
member of the public and compares them with the MILDOS-AREA code
results. It was assumed that ^234^U is in equilibrium with ^238^U in air
inhalation pathway dose calculations. The table also provides the ^238^U
air concentration and the inhalation DCFs for ^234^U and ^238^U used in
the calculations. The listed DCFs are the committed effective dose
equivalents for an adult member of the public for a particle size of 3
μm using the calculated air concentration (see Table 2.7). The
difference between the calculated values and the values in the
MILDOS-AREA report was less than 5% (see Table 2.8)

.

  ------------- --------------- ------------ -------- ------------ ------------ ---------- ------------ --
  **TABLE 2.8                                                                                           
  Comparison of                                                                                         
  Inhalation                                                                                            
  Pathway Doses                                                                                         
  at Different                                                                                          
  Receptor                                                                                              
  Locations**                                                                                           

  Receptor\     Air             Effective                          Adult                                
  downwind      concentration   inhalation                         inhalation                           
  distance\     (pCi/m^3^)      DCF (mrem/yr                       dose                                 
  (m)                           per                                (mrem/yr)                            
                                pCi/m^3^)                                                               

                                ^238^U       ^234^U   Calculated                Reported   Reported/\   
                                                                                           calculated   
                                                                                           ratio        

  42.4          8.33E-02        434          485      7.66E+01                  7.16E+01   9.35E-01     

  56.6          4.75E-02        434          485      4.37E+01                  4.15E+01   9.50E-01     

  70.7          3.08E-02        434          485      2.83E+01                  2.71E+01   9.59E-01     

  99.0          1.60E-02        434          485      1.47E+01                  1.42E+01   9.68E-01     

  141.4         7.95E-03        434          485      7.31E+00                  7.38E+00   1.01E+00     
  ------------- --------------- ------------ -------- ------------ ------------ ---------- ------------ --

**2.6 EXTERNAL PATHWAY DOSE**

The external pathway dose in the MILDOS-AREA code includes doses from
air submersion and direct external exposure pathways. Dose is calculated
by assuming 100% occupancy at a given receptor location. A structural
shielding factor of 0.825 is applied, which accounts for indoor
occupancy of 14 hours per day with a shielding factor of 0.7. The dose
is calculated using Equation 2.4-4 in Strenge and Bander (1981), given
as:

$$D_{l}(\text{ext}) = 0\text{.}\text{825}\sum_{}^{}\left\lbrack x(s)\text{DCF}_{l}(\text{imm}\text{.}) + x_{g}\text{DCF}_{l}(\text{gnd}) \right\rbrack$$

where:

*x(s)* = total air concentration for particle size *s* at a given
receptor location, pCi/m^3^,

*X~g~* = ground surface concentration at a given receptor location,
pCi/m^2^,

*DCF~l~(imm.)* = dose conversion factor for external exposure to the
cloud air submersion for organ *l*, mrem/yr per pCi/m^3^,

*DCF~l~(gnd)* = dose conversion factor for direct exposure to
contaminated ground for organ *l*, mrem/yr per pCi/m^2^, and

0.825 = factor to account for shielding for indoor occupancy.

The air submersion and direct external exposure pathway doses were
calculated separately using the above equation and compared with the
MILDOS-AREA report. The effective dose equivalent for an adult member of
the public was compared.

Table 2.9 lists the calculated air submersion pathway doses for an adult
member of the public and compares them with the MILDOS-AREA code
results. The table also provides the air concentration and the air
submersion DCFs for ^238^U used in the calculations. The ^238^U air
submersion DCF includes contributions from daughters ^234^Th, ^234m^Pa,
and ^234^U. The listed DCF is the effective dose equivalent for an adult
member of the public. The calculated air concentration was used in the
calculations (see Table 2.7). The difference between the calculated
values and the values in the MILDOS-AREA report was less than 7% (see
Table 2.9).

  ------------- --------------- ------------ ------------ ----------- ---------------
  **TABLE 2.9                                                         
  Comparison of                                                       
  Air                                                                 
  Submersion                                                          
  Pathway Doses                                                       
  at Different                                                        
  Receptor                                                            
  Locations**                                                         

                                             Immersion                
                                             dose                     
                                             (mrem/yr)                

  Receptor      Air             Air          Calculated   Reported    Reported/\
  downwind      concentration   submersion                            calculated
  distance (m)  (pCi/m^3^)      DCF (mrem/yr                          ratio
                                per                                   
                                pCi/m^3^)                             

  42.4          8.33E-02        1.23E-04     8.46E-06     7.90E-06    9.34E-01

  56.6          4.75E-02        1.23E-04     4.82E-06     4.58E-06    9.49E-01

  70.7          3.08E-02        1.23E-04     3.12E-06     2.99E-06    9.58E-01

  99.0          1.60E-02        1.23E-04     1.62E-06     1.57E-06    9.70E-01

  141.4         7.95E-03        1.23E-04     8.07E-07     8.15E-07    1.01E+00
  ------------- --------------- ------------ ------------ ----------- ---------------

Table 2.10 lists the calculated direct external exposure pathway doses
for an adult member of the public and compares it with the MILDOS-AREA
code results. The table also provides the ground concentration and the
direct external ground DCFs for ^238^U used in the calculations. The
^238^U direct external ground DCF includes contributions from daughters
^234^Th, ^234m^Pa, and ^234^U. The listed DCF is the effective dose
equivalent for an adult member of the public. In these calculations, the
calculated ground concentration was used (see Table 2.6). The difference
between the calculated values and the values in the MILDOS-AREA report
was less than 5% (see Table 2.10).

+--------+-----------+-----------+----------+-----------+-----------+
| *      |           |           |          |           |           |
| *TABLE |           |           |          |           |           |
| 2.10   |           |           |          |           |           |
| Comp   |           |           |          |           |           |
| arison |           |           |          |           |           |
| of     |           |           |          |           |           |
| Direct |           |           |          |           |           |
| Ex     |           |           |          |           |           |
| ternal |           |           |          |           |           |
| Ex     |           |           |          |           |           |
| posure |           |           |          |           |           |
| P      |           |           |          |           |           |
| athway |           |           |          |           |           |
| Doses  |           |           |          |           |           |
| at     |           |           |          |           |           |
| Dif    |           |           |          |           |           |
| ferent |           |           |          |           |           |
| Re     |           |           |          |           |           |
| ceptor |           |           |          |           |           |
| Locat  |           |           |          |           |           |
| ions** |           |           |          |           |           |
+--------+-----------+-----------+----------+-----------+-----------+
|        |           |           | Direct   |           |           |
|        |           |           | external |           |           |
|        |           |           | dose     |           |           |
|        |           |           | (        |           |           |
|        |           |           | mrem/yr) |           |           |
+--------+-----------+-----------+----------+-----------+-----------+
| Re     | Ground    | Direct    | Ca       | Reported  | R         |
| ceptor | conc      | external  | lculated |           | eported/\ |
|        | entration | DCF       |          |           | c         |
| do     | (         | (mrem/yr  |          |           | alculated |
| wnwind | pCi/m^2^) | per       |          |           | ratio     |
| di     |           | pCi/m^2^) |          |           |           |
| stance |           |           |          |           |           |
| (m)    |           |           |          |           |           |
+--------+-----------+-----------+----------+-----------+-----------+
| 42.4   | 7.68E+04  | 3.70E-06  | 2.35E-01 | 2.23E-01  | 9.51E-01  |
+--------+-----------+-----------+----------+-----------+-----------+
| 56.6   | 4.38E+04  | 3.70E-06  | 1.34E-01 | 1.29E-01  | 9.64E-01  |
+--------+-----------+-----------+----------+-----------+-----------+
| 70.7   | 2.84E+04  | 3.70E-06  | 8.66E-02 | 8.45E-02  | 9.76E-01  |
+--------+-----------+-----------+----------+-----------+-----------+
| 99.0   | 1.47E+04  | 3.70E-06  | 4.49E-02 | 4.43E-02  | 9.87E-01  |
+--------+-----------+-----------+----------+-----------+-----------+
| 141.4  | 7.33E+03  | 3.70E-06  | 2.24E-02 | 2.30E-02  | 1.03E+00  |
+--------+-----------+-----------+----------+-----------+-----------+

**2.7 INGESTION PATHWAY DOSES**

The ingestion pathway dose in the MILDOS-AREA code includes the
ingestion dose from plant, meat, and milk ingestion subpathways. The
annual radionuclide intake by ingestion is calculated using ingestion
rates of different food types by receptor age group, and activity
concentration in the food type. For plant ingestion it is assumed that
50% of the activity remains after food preparation. The radionuclide
intake is multiplied by ingestion dose conversion factors to calculate
the ingestion pathway doses.

The radionuclide concentration in plants in the MILDOS-AREA code is
calculated using air and ground concentrations. The code includes five
categories of plants: edible above-ground vegetables, potatoes, other
edible below-ground vegetables, pasture grass, and hay. Pasture grass
and hay are included for the meat and milk ingestion pathways (i.e.,
they are only used by cattle). The plants become contaminated from root
uptake and foliar deposition. The radionuclide concentration in plants
in calculated using Equation 2.3-3 in Strenge and Bander (1981), given
as:

> $C_{v} = w_{s}F_{r}E_{v}\left( \frac{1 - e^{- \lambda_{w}t_{v}}}{Y_{v}\lambda_{w}} \right) + x_{g}\frac{B_{v}}{\rho_{p}}$

where:

*C~v~* = radionuclide concentration in plant type *v*, pCi/kg,

*W~s~* = deposition rate, pCi/(m^2^.sec),

*F~r~* = foliar interception fraction, 0.2,

*E~v~* = fraction of foliar deposition reaching edible portion in plant
type *v*,

$\lambda_{w}$= decay constant to account for weathering losses, sec^-1^,

*t~v~* = growing period for plant type *v*, sec,

*Y~v~* = wet crop yield for plant type *v*, kg/m^2^,

*X~g~* = ground concentration, pCi/m^2^,

*B~v~* = soil-to-plant transfer coefficient for plant type *v*, and

$\rho_{p}$= soil areal density for plowing, 240 kg/m^2^.

The radionuclide concentrations in five plant types were calculated
using the above equation and the default parameters. Tables 2.11 through
2.15 list radionuclide concentrations for five plant types. Radionuclide
concentrations are calculated at five receptor locations. The
concentrations in potatoes and edible below-ground vegetables and edible
above-ground vegetables and hay were the same. The maximum radionuclide
concentration was in pasture grass (see Table 2.14).

The radionuclide concentration in meat is calculated using Equation
2.3-4 in Strenge and Bander (1981), given as:

$$C_{b} = \text{QF}_{b}\left( F_{\text{pg}}C_{\text{pg}} + F_{h}C_{h} \right)$$

where:

*C~b~* = average radionuclide concentration in meat, pCi/kg,

*Q* = feed ingestion rate of meat cow, kg/day,

*F~b~* = feed-to-meat transfer coefficient, pCi/kg per pCi/day ingested,

*F~pg~* = feed fraction from pasture grass, and

*F~h~* = feed fraction from stored feed (hay).

<table>
<colgroup>
<col style="width: 8%" />
<col style="width: 11%" />
<col style="width: 11%" />
<col style="width: 11%" />
<col style="width: 8%" />
<col style="width: 4%" />
<col style="width: 4%" />
<col style="width: 9%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 7%" />
<col style="width: 9%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="12"><strong>TABLE 2.11 Radionuclide Concentrations in
Edible Above-Ground Vegetables</strong></td>
</tr>
<tr class="even">
<td>Foodstuff distance (m)</td>
<td>Air concentration (pCi/m<sup>3</sup>)</td>
<td>Deposition rate [pCi/(m<sup>2</sup>.sec)]</td>
<td>Ground concentration (pCi/m<sup>2</sup>)</td>
<td><em>B<sub>v</sub></em></td>
<td><em>F<sub>r</sub></em></td>
<td><em>E<sub>v</sub></em></td>
<td><p><em>λ<sub>w</sub></em></p>
<p>(sec<sup>-1</sup>)</p></td>
<td><p><em>T<sub>v</sub></em></p>
<p>(sec)</p></td>
<td><em>Y<sub>v </sub></em>(kg/m<sup>2</sup>)</td>
<td><em>ρ<sub>p</sub></em> (kg/m<sup>2</sup>)</td>
<td><p><em>C<sub>v</sub></em></p>
<p>(pCi/kg)</p></td>
</tr>
<tr class="odd">
<td>42.4</td>
<td>8.33E-02</td>
<td>8.33E-04</td>
<td>7.68E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.39E+02</td>
</tr>
<tr class="even">
<td>56.6</td>
<td>4.75E-02</td>
<td>4.75E-04</td>
<td>4.38E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>7.92E+01</td>
</tr>
<tr class="odd">
<td>70.7</td>
<td>3.08E-02</td>
<td>3.08E-04</td>
<td>2.84E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>5.12E+01</td>
</tr>
<tr class="even">
<td>99.0</td>
<td>1.60E-02</td>
<td>1.60E-04</td>
<td>1.47E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>2.66E+01</td>
</tr>
<tr class="odd">
<td>141.4</td>
<td>7.95E-03</td>
<td>7.95E-05</td>
<td>7.33E+03</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.32E+01</td>
</tr>
</tbody>
</table>

<table>
<colgroup>
<col style="width: 8%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 8%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="12"><strong>TABLE 2.12 Radionuclide Concentrations in
Potatoes</strong></td>
</tr>
<tr class="even">
<td>Foodstuff distance (m)</td>
<td>Air concentration (pCi/m<sup>3</sup>)</td>
<td>Deposition rate [pCi/(m<sup>2</sup>.sec)]</td>
<td>Ground concentration (pCi/m<sup>2</sup>)</td>
<td><em>B<sub>v</sub></em></td>
<td><em>F<sub>r</sub></em></td>
<td><em>E<sub>v</sub></em></td>
<td><p><em>λ<sub>w</sub></em></p>
<p>(sec<sup>-1</sup>)</p></td>
<td><p><em>T<sub>v</sub></em></p>
<p>(sec)</p></td>
<td><em>Y<sub>v </sub></em>(kg/m<sup>2</sup>)</td>
<td><em>ρ<sub>p</sub></em> (kg/m<sup>2</sup>)</td>
<td><p><em>C<sub>v</sub></em></p>
<p>(pCi/kg)</p></td>
</tr>
<tr class="odd">
<td>42.4</td>
<td>8.33E-02</td>
<td>8.33E-04</td>
<td>7.68E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.46E+01</td>
</tr>
<tr class="even">
<td>56.6</td>
<td>4.75E-02</td>
<td>4.75E-04</td>
<td>4.38E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>8.33E+00</td>
</tr>
<tr class="odd">
<td>70.7</td>
<td>3.08E-02</td>
<td>3.08E-04</td>
<td>2.84E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>5.39E+00</td>
</tr>
<tr class="even">
<td>99.0</td>
<td>1.60E-02</td>
<td>1.60E-04</td>
<td>1.47E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>2.79E+00</td>
</tr>
<tr class="odd">
<td>141.4</td>
<td>7.95E-03</td>
<td>7.95E-05</td>
<td>7.33E+03</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.39E+00</td>
</tr>
</tbody>
</table>

<table>
<colgroup>
<col style="width: 8%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 8%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="12"><strong>TABLE 2.13 Radionuclide Concentrations in
Edible Below-Ground Vegetables</strong></td>
</tr>
<tr class="even">
<td>Foodstuff distance (m)</td>
<td>Air concentration (pCi/m<sup>3</sup>)</td>
<td>Deposition rate [pCi/(m<sup>2</sup>.sec)]</td>
<td>Ground concentration (pCi/m<sup>2</sup>)</td>
<td><em>B<sub>v</sub></em></td>
<td><em>F<sub>r</sub></em></td>
<td><em>E<sub>v</sub></em></td>
<td><p><em>λ<sub>w</sub></em></p>
<p>(sec<sup>-1</sup>)</p></td>
<td><p><em>T<sub>v</sub></em></p>
<p>(sec)</p></td>
<td><em>Y<sub>v</sub></em> (kg/m<sup>2</sup>)</td>
<td><em>ρ<sub>p</sub></em> (kg/m<sup>2</sup>)</td>
<td><p><em>C<sub>v</sub></em></p>
<p>(pCi/kg)</p></td>
</tr>
<tr class="odd">
<td>42.4</td>
<td>8.33E-02</td>
<td>8.33E-04</td>
<td>7.68E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.46E+01</td>
</tr>
<tr class="even">
<td>56.6</td>
<td>4.75E-02</td>
<td>4.75E-04</td>
<td>4.38E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>8.33E+00</td>
</tr>
<tr class="odd">
<td>70.7</td>
<td>3.08E-02</td>
<td>3.08E-04</td>
<td>2.84E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>5.39E+00</td>
</tr>
<tr class="even">
<td>99.0</td>
<td>1.60E-02</td>
<td>1.60E-04</td>
<td>1.47E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>2.79E+00</td>
</tr>
<tr class="odd">
<td>141.4</td>
<td>7.95E-03</td>
<td>7.95E-05</td>
<td>7.33E+03</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>0.1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.39E+00</td>
</tr>
</tbody>
</table>

<table>
<colgroup>
<col style="width: 8%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 8%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="12"><strong>TABLE 2.14 Radionuclide Concentrations in
Pasture Grass</strong></td>
</tr>
<tr class="even">
<td>Foodstuff distance (m)</td>
<td>Air concentration (pCi/m<sup>3</sup>)</td>
<td>Deposition rate [pCi/(m<sup>2</sup>.sec)]</td>
<td>Ground concentration (pCi/m<sup>2</sup>)</td>
<td><em>B<sub>v</sub></em></td>
<td><em>F<sub>r</sub></em></td>
<td><em>E<sub>v</sub></em></td>
<td><p><em>λ<sub>w</sub></em></p>
<p>(sec<sup>-1</sup>)</p></td>
<td><p><em>T<sub>v </sub></em></p>
<p>(sec)</p></td>
<td><em>Y<sub>v </sub></em>(kg/m<sup>2</sup>)</td>
<td><em>ρ<sub>p</sub></em> (kg/m<sup>2</sup>)</td>
<td><p><em>C<sub>v</sub></em></p>
<p>(pCi/kg)</p></td>
</tr>
<tr class="odd">
<td>42.4</td>
<td>8.33E-02</td>
<td>8.33E-04</td>
<td>7.68E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>2.59E+06</td>
<td>0.75</td>
<td>240</td>
<td>3.01E+02</td>
</tr>
<tr class="even">
<td>56.6</td>
<td>4.75E-02</td>
<td>4.75E-04</td>
<td>4.38E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>2.59E+06</td>
<td>0.75</td>
<td>240</td>
<td>1.72E+02</td>
</tr>
<tr class="odd">
<td>70.7</td>
<td>3.08E-02</td>
<td>3.08E-04</td>
<td>2.84E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>2.59E+06</td>
<td>0.75</td>
<td>240</td>
<td>1.11E+02</td>
</tr>
<tr class="even">
<td>99.0</td>
<td>1.60E-02</td>
<td>1.60E-04</td>
<td>1.47E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>2.59E+06</td>
<td>0.75</td>
<td>240</td>
<td>5.76E+01</td>
</tr>
<tr class="odd">
<td>141.4</td>
<td>7.95E-03</td>
<td>7.95E-05</td>
<td>7.33E+03</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>2.59E+06</td>
<td>0.75</td>
<td>240</td>
<td>2.87E+01</td>
</tr>
</tbody>
</table>

<table>
<colgroup>
<col style="width: 8%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 10%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 7%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 8%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="12"><strong>TABLE 2.15 Radionuclide Concentrations in
Hay</strong></td>
</tr>
<tr class="even">
<td>Foodstuff distance (m)</td>
<td>Air concentration (pCi/m<sup>3</sup>)</td>
<td>Deposition rate [pCi/(m<sup>2</sup>.sec)]</td>
<td>Ground concentration (pCi/m<sup>2</sup>)</td>
<td><em>B<sub>v</sub></em></td>
<td><em>F<sub>r</sub></em></td>
<td><em>E<sub>v</sub></em></td>
<td><p><em>λ<sub>w</sub></em></p>
<p>(sec<sup>-1</sup>)</p></td>
<td><p><em>T<sub>v</sub></em></p>
<p>(sec)</p></td>
<td><em>Y<sub>v</sub></em> (kg/m<sup>2</sup>)</td>
<td><em>ρ<sub>p</sub></em> (kg/m<sup>2</sup>)</td>
<td><p><em>C<sub>v</sub></em></p>
<p>(pCi/kg)</p></td>
</tr>
<tr class="odd">
<td>42.4</td>
<td>8.33E-02</td>
<td>8.33E-04</td>
<td>7.68E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.39E+02</td>
</tr>
<tr class="even">
<td>56.6</td>
<td>4.75E-02</td>
<td>4.75E-04</td>
<td>4.38E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>7.92E+01</td>
</tr>
<tr class="odd">
<td>70.7</td>
<td>3.08E-02</td>
<td>3.08E-04</td>
<td>2.84E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>5.12E+01</td>
</tr>
<tr class="even">
<td>99.0</td>
<td>1.60E-02</td>
<td>1.60E-04</td>
<td>1.47E+04</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>2.66E+01</td>
</tr>
<tr class="odd">
<td>141.4</td>
<td>7.95E-03</td>
<td>7.95E-05</td>
<td>7.33E+03</td>
<td>2.50E-03</td>
<td>0.2</td>
<td>1</td>
<td>5.73E-07</td>
<td>5.18E+06</td>
<td>2</td>
<td>240</td>
<td>1.32E+01</td>
</tr>
</tbody>
</table>

The radionuclide concentration in milk is calculated using Equation
2.3-5 in Strenge and Bander (1981), given as:

$$C_{m} = \text{QF}_{m}\left( F_{\text{pg}}C_{\text{pg}} + F_{h}C_{h} \right)$$

where:

*C~m~* = average radionuclide concentration in milk, pCi/kg,

*Q* = feed ingestion rate of milk cow, kg/day,

*F~m~* = feed-to-milk transfer coefficient, pCi/kg per pCi/day ingested,

*F~pg~* = feed fraction from pasture grass, and

*F~h~* = feed fraction from stored feed (hay).

The above equations were used to calculate meat and milk radionuclide
concentrations, shown in Tables 2.16 and 2.17, respectively.

  ---------------- ---------- ---------- --------- -------- ----------- ---------- ----------
  **TABLE 2.16                                                                     
  Radionuclide                                                                     
  Concentrations                                                                   
  in Meat**                                                                        

  Foodstuff        *C~pg~*    *C~h~*     *F~pg~*   *F~h~*   *F~b~*      *Q*        *C~b~*
  distance (m)     (pCi/kg)   (pCi/kg)                      (pCi/kg per (kg/day)   (pCi/kg)
                                                            pCi/day)               

  42.4             3.01E+02   1.39E+02   0.5       0.5      3.40E-04    50         3.74E+00

  56.6             1.72E+02   7.92E+01   0.5       0.5      3.40E-04    50         2.13E+00

  70.7             1.11E+02   5.12E+01   0.5       0.5      3.40E-04    50         1.38E+00

  99.0             5.76E+01   2.66E+01   0.5       0.5      3.40E-04    50         7.15E-01

  141.4            2.87E+01   1.32E+01   0.5       0.5      3.40E-04    50         3.57E-01
  ---------------- ---------- ---------- --------- -------- ----------- ---------- ----------

+--------+--------+--------+-----+-----+----------+------+----------+
| *      |        |        |     |     |          |      |          |
| *TABLE |        |        |     |     |          |      |          |
| 2.17   |        |        |     |     |          |      |          |
| Radion |        |        |     |     |          |      |          |
| uclide |        |        |     |     |          |      |          |
| Co     |        |        |     |     |          |      |          |
| ncentr |        |        |     |     |          |      |          |
| ations |        |        |     |     |          |      |          |
| in     |        |        |     |     |          |      |          |
| Milk** |        |        |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+
| Foo    | *      | *C~h~* | *   | *F~ | *F~m~*   | *Q*  | *C~m~*   |
| dstuff | C~pg~* | (p     | F~p | h~* | (pCi/kg  | (kg/ | (pCi/kg) |
| di     |        | Ci/kg) | g~* |     | per      | day) |          |
| stance | (p     |        |     |     | pCi/day) |      |          |
| (m)    | Ci/kg) |        |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+
| 42.4   | 3.     | 1.     | 0.5 | 0.5 | 6.10E-04 | 50   | 6.70E+00 |
|        | 01E+02 | 39E+02 |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+
| 56.6   | 1.     | 7.     | 0.5 | 0.5 | 6.10E-04 | 50   | 3.82E+00 |
|        | 72E+02 | 92E+01 |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+
| 70.7   | 1.     | 5.     | 0.5 | 0.5 | 6.10E-04 | 50   | 2.47E+00 |
|        | 11E+02 | 12E+01 |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+
| 99.0   | 5.     | 2.     | 0.5 | 0.5 | 6.10E-04 | 50   | 1.28E+00 |
|        | 76E+01 | 66E+01 |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+
| 141.4  | 2.     | 1.     | 0.5 | 0.5 | 6.10E-04 | 50   | 6.40E-01 |
|        | 87E+01 | 32E+01 |     |     |          |      |          |
+--------+--------+--------+-----+-----+----------+------+----------+

In the MILDOS-AREA code the total intake by plant ingestion is
calculated using Equation 2.4-2 in Strenge and Bander (1981), given as:

$I_{\text{pk}} = 0\text{.}5\sum_{v}^{}{U_{\text{pk}}f_{\text{vk}}C_{v}}$

where:

*I~pk~* = annual radionuclide intake for age group *k* from plant
ingestion, pCi/yr,

*U~pk~* = total plant ingestion rate for age group *k*, kg/yr,

*f~vk~* = intake fraction from vegetable type *v* for age group *k*,

*C~v~* = radionuclide concentration in plant type *v*, pCi/kg, and

0.5 = the fraction of activity in vegetables remaining after food
preparation.

Plant ingestion dose is calculated as:

$$D_{\text{pkl}} = I_{\text{pk}}\text{DCF}_{\text{lk}}(\text{ing})$$

where:

*D~pkl~* = plant ingestion dose for organ *l* and age group *k*,
mrem/yr, and

*DCF~lk~(ing)* = ingestion dose conversion factor for organ *l* and age
group *k*, mrem/pCi.

Table 2.18 provides the plant ingestion dose calculations for an adult
member of the public. Committed effective dose equivalents were
calculated at five receptor locations and compared with the values in
the MILDOS-AREA report. For these calculations it was assumed that
^234^U was in equilibrium with ^238^U. The difference between the
calculated values and the values in the MILDOS-AREA report was less than
5%.

Meat ingestion dose is calculated as:

$$D_{\text{bkl}} = U_{\text{bk}}C_{b}\text{DCF}_{\text{lk}}(\text{ing})$$

*where:*

*D~bkl~* = meat ingestion dose for organ *l* and age group *k*, mrem/yr,

*U~bk~* = meat ingestion rate for age group *k*, kg/yr,

*C~b~* = radionuclide concentration in meat, pCi/kg, and

*DCF~lk~(ing)* = ingestion dose conversion factor for organ *l* and age
group *k*, mrem/pCi.

<table>
<colgroup>
<col style="width: 8%" />
<col style="width: 5%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 5%" />
<col style="width: 8%" />
<col style="width: 7%" />
<col style="width: 11%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 10%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="13"><strong>TABLE 2.18 Plant Ingestion Pathway Dose
Comparison at Different Receptor Locations</strong></td>
</tr>
<tr class="even">
<td rowspan="2"><p>Receptor</p>
<p>downwind</p>
<p>distance</p>
<p>(m)</p></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"><p>Ingestion DCF</p>
<p>(mrem/pCi)</p></td>
<td colspan="3"><p>Plant ingestion dose</p>
<p>(mrem/yr)</p></td>
</tr>
<tr class="odd">
<td><em>U</em> (kg/yr)</td>
<td><em>f<sub>ag</sub></em></td>
<td><em>C<sub>ag </sub></em>(pCi/kg)</td>
<td><em>f<sub>p</sub></em></td>
<td><em>C<sub>p</sub></em> (pCi/kg)</td>
<td><em>f<sub>bg</sub></em></td>
<td><em>C<sub>bg</sub></em> (pCi/kg)</td>
<td><sup>238</sup>U</td>
<td><sup>234</sup>U</td>
<td>Calc.</td>
<td>Report.</td>
<td>Report/calc. ratio</td>
</tr>
<tr class="even">
<td>42.4</td>
<td>105.3</td>
<td>0.378</td>
<td>1.39E+02</td>
<td>0.573</td>
<td>1.46E+01</td>
<td>0.049</td>
<td>1.46E+01</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td>1.75E+00</td>
<td>1.67E+00</td>
<td>9.56E-01</td>
</tr>
<tr class="odd">
<td>56.6</td>
<td>105.3</td>
<td>0.378</td>
<td>7.92E+01</td>
<td>0.573</td>
<td>8.33E+00</td>
<td>0.049</td>
<td>8.33E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td>9.96E-01</td>
<td>9.69E-01</td>
<td>9.73E-01</td>
</tr>
<tr class="even">
<td>70.7</td>
<td>105.3</td>
<td>0.378</td>
<td>5.12E+01</td>
<td>0.573</td>
<td>5.39E+00</td>
<td>0.049</td>
<td>5.39E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td>6.45E-01</td>
<td>6.33E-01</td>
<td>9.82E-01</td>
</tr>
<tr class="odd">
<td>99.0</td>
<td>105.3</td>
<td>0.378</td>
<td>2.66E+01</td>
<td>0.573</td>
<td>2.79E+00</td>
<td>0.049</td>
<td>2.79E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td>3.34E-01</td>
<td>3.32E-01</td>
<td>9.93E-01</td>
</tr>
<tr class="even">
<td>141.4</td>
<td>105.3</td>
<td>0.378</td>
<td>1.32E+01</td>
<td>0.573</td>
<td>1.39E+00</td>
<td>0.049</td>
<td>1.39E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td>1.67E-01</td>
<td>1.73E-01</td>
<td>1.04E+00</td>
</tr>
</tbody>
</table>

Table 2.19 provides the meat ingestion dose calculations for an adult
member of the public. Committed effective dose equivalent was calculated
for five receptor locations and compared with the values in the
MILDOS-AREA report. For these calculations it was assumed that ^234^U
was in equilibrium with ^238^U. The difference between the calculated
values and the values in the MILDOS-AREA report was less than 5%.

<table style="width:100%;">
<colgroup>
<col style="width: 11%" />
<col style="width: 10%" />
<col style="width: 11%" />
<col style="width: 15%" />
<col style="width: 11%" />
<col style="width: 2%" />
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 13%" />
<col style="width: 2%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="10"><strong>TABLE 2.19 Meat Ingestion Pathway Dose
Comparison at Different Receptor Locations</strong></td>
</tr>
<tr class="even">
<td rowspan="2"><p>Receptor</p>
<p>downwind</p>
<p>distance</p>
<p>(m)</p></td>
<td></td>
<td></td>
<td colspan="2">Ingestion DCF (mrem/pCi)</td>
<td></td>
<td colspan="3">Meat ingestion dose (mrem/yr)</td>
<td></td>
</tr>
<tr class="odd">
<td><p><em>U<sub>b </sub></em></p>
<p>(kg/yr)</p></td>
<td><em>C<sub>b</sub></em> (pCi/kg)</td>
<td><sup>238</sup>U</td>
<td><sup>234</sup>U</td>
<td colspan="2">Calculated</td>
<td>Reported</td>
<td colspan="2"><p>Reported/</p>
<p>calculated</p>
<p>ratio</p></td>
</tr>
<tr class="even">
<td>42.4</td>
<td>78.3</td>
<td>3.74E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td colspan="2">1.58E-01</td>
<td>1.51E-01</td>
<td colspan="2">9.57E-01</td>
</tr>
<tr class="odd">
<td>56.6</td>
<td>78.3</td>
<td>2.13E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td colspan="2">9.00E-02</td>
<td>8.75E-02</td>
<td colspan="2">9.73E-01</td>
</tr>
<tr class="even">
<td>70.7</td>
<td>78.3</td>
<td>1.38E+00</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td colspan="2">5.82E-02</td>
<td>5.71E-02</td>
<td colspan="2">9.81E-01</td>
</tr>
<tr class="odd">
<td>99.0</td>
<td>78.3</td>
<td>7.15E-01</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td colspan="2">3.02E-02</td>
<td>3.00E-02</td>
<td colspan="2">9.94E-01</td>
</tr>
<tr class="even">
<td>141.4</td>
<td>78.3</td>
<td>3.57E-01</td>
<td>2.55E-04</td>
<td>2.84E-04</td>
<td colspan="2">1.50E-02</td>
<td>1.56E-02</td>
<td colspan="2">1.04E+00</td>
</tr>
</tbody>
</table>

Milk ingestion dose is calculated as:

$$D_{\text{mkl}} = U_{\text{mk}}C_{m}\text{DCF}_{\text{lk}}(\text{ing})$$

*where:*

*D~mkl\ ~*= milk ingestion dose for organ *l* and age group *k*,
mrem/yr,

*U~mk~* = milk ingestion rate for age group *k*, kg/yr,

*C~m~* = radionuclide concentration in milk, pCi/kg, and

*DCF~lk~(ing)* = ingestion dose conversion factor for organ *l* and age
group *k*, mrem/pCi.

Table 2.20 provides the milk ingestion dose calculations for an adult
member of the public. Committed effective dose equivalents were
calculated at five receptor locations and compared with the values in
the MILDOS-AREA report. In these calculations it was assumed that ^234^U
was in equilibrium with ^238^U. The difference between the calculated
values and the values in the MILDOS-AREA report was less than 5%.

<table style="width:100%;">
<colgroup>
<col style="width: 11%" />
<col style="width: 9%" />
<col style="width: 11%" />
<col style="width: 2%" />
<col style="width: 11%" />
<col style="width: 14%" />
<col style="width: 2%" />
<col style="width: 0%" />
<col style="width: 2%" />
<col style="width: 9%" />
<col style="width: 11%" />
<col style="width: 10%" />
<col style="width: 2%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="13"><strong>TABLE 2.20 Milk Ingestion Pathway Dose
Comparison at Different Receptor Locations</strong></td>
</tr>
<tr class="even">
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="2">Ingestion DCF (mrem/pCi)</td>
<td colspan="2"></td>
<td></td>
<td colspan="3">Milk ingestion dose (mrem/yr)</td>
<td></td>
</tr>
<tr class="odd">
<td><p>Receptor</p>
<p>downwind</p>
<p>distance</p>
<p>(m)</p></td>
<td><p><em>U<sub>m</sub></em></p>
<p>(kg/yr)</p></td>
<td><em>C<sub>m</sub></em> (pCi/kg)</td>
<td colspan="2"><sup>238</sup>U</td>
<td colspan="2"><sup>234</sup>U</td>
<td colspan="3">Calculated</td>
<td>Reported</td>
<td colspan="2">Reported/<br />
calculated<br />
ratio</td>
</tr>
<tr class="even">
<td>42.4</td>
<td>130</td>
<td>6.70E+00</td>
<td colspan="2">2.55E-04</td>
<td colspan="2">2.84E-04</td>
<td colspan="3">4.70E-01</td>
<td>4.50E-01</td>
<td colspan="2">9.58E-01</td>
</tr>
<tr class="odd">
<td>56.6</td>
<td>130</td>
<td>3.82E+00</td>
<td colspan="2">2.55E-04</td>
<td colspan="2">2.84E-04</td>
<td colspan="3">2.68E-01</td>
<td>2.61E-01</td>
<td colspan="2">9.74E-01</td>
</tr>
<tr class="even">
<td>70.7</td>
<td>130</td>
<td>2.47E+00</td>
<td colspan="2">2.55E-04</td>
<td colspan="2">2.84E-04</td>
<td colspan="3">1.73E-01</td>
<td>1.70E-01</td>
<td colspan="2">9.80E-01</td>
</tr>
<tr class="odd">
<td>99.0</td>
<td>130</td>
<td>1.28E+00</td>
<td colspan="2">2.55E-04</td>
<td colspan="2">2.84E-04</td>
<td colspan="3">8.99E-02</td>
<td>8.93E-02</td>
<td colspan="2">9.93E-01</td>
</tr>
<tr class="even">
<td>141.4</td>
<td>130</td>
<td>6.40E-01</td>
<td colspan="2">2.55E-04</td>
<td colspan="2">2.84E-04</td>
<td colspan="3">4.48E-02</td>
<td>4.64E-02</td>
<td colspan="2">1.04E+00</td>
</tr>
</tbody>
</table>

**3 COMPARISON WITH RESRAD-OFFSITE**

A limited comparison of the MILDOS-AREA code with the air dispersion
component of the RESRAD-OFFSITE code (Version 2.0) was performed. For
most of the comparison it was assumed that there was a point source
release of 1 mCi/yr of ^238^U at ground level in the MILDOS-AREA code
and that the receptor was located at ground level at different downwind
distances in a specified direction. For the Chi/Q and release rate
comparison it was also assumed that the release was from the 100‑m^2^
area contaminated at 1 pCi/g of ^238^U. To simplify hand calculations it
was assumed that the wind was blowing at 10 mph in the direction of the
receptor and that there had been five years of continuous release.

RESRAD-OFFSITE parameters were adjusted as much as possible to match
MILDOS-AREA code assumptions for the comparison. To simulate point
source releases, a very small area (0.01 m^2^) of primary contaminated
source was selected. The four agricultural areas in RESRAD-OFFSITE were
at different distances from the primary contaminated areas and were also
small (0.01 m^2^). The receptor was outside at the center of these
agricultural areas. Pasquill-Gifford dispersion coefficients were used
for ground-level releases.

The following components of the codes were compared:

-   Chi/Q at different distances ranging from 60 m -- 14 km, for point
    source

-   Chi/Q at different distances ranging from 50 m -- 14 km, for
    100-m^2^ area source

-   Release rate for 100-m^2^ area source at 10 mph wind speed

-   Dust Inhalation pathway dose at four offsite locations

-   Ground deposition -- soil concentration at four offsite locations

-   External exposure pathway doses at four offsite locations

-   Plant, meat, and milk concentrations at one offsite location

-   Plant, meat, and milk ingestion pathway doses at one offsite
    location

The main differences in the two codes are summarized in Section 3.9.

**3.1 Chi/Q Comparison**

RESRAD-OFFSITE uses the Gaussian plume dispersion model for atmospheric
transport. The model preserves mass balance and accounts for depletion
of the plume from dry and wet deposition processes. The code performs a
spatial integration of the atmospheric transport by subdividing the
primary contamination and the receptor regions into small squares. The
center point of each square is used as the source or receptor point
representing that small area. Area concentrations are calculated for
each receptor square for emissions from every source square. Finally,
the average concentration over the whole receptor area is calculated.
See Section 4 of the RESRAD-OFFSITE Manual (Yu et al. 2007) for detailed
discussion of the atmospheric transport model.

The MILDOS-AREA code also uses the Gaussian plume dispersion model for
atmospheric transport, but it does not include plume depletion from wet
deposition. The code allows point source release, as well. Both codes
use a polar grid with 16 sectors to specify the wind direction and
calculate sector average air concentration. For this comparison only dry
deposition was included for RESRAD-OFFSITE (precipitation is set at 0
m/yr). Both codes use similar dispersion coefficients (see Table 4.2 in
Yu et al. \[2007\] and Table 2.1 in Yuan et al. \[1989\]).

Table 3.1 compares Chi/Q calculated by both codes at different downwind
distances (56.6 m -- 14,142 m) for all stability classes for the point
source. There was good agreement, with differences less than 5% for all
downwind distances, except at 14,142 m for stability classes E and F.

Table 3.2 compares Chi/Q calculated by both codes at different downwind
distances (50 m -- 14,135 m) for all stability classes for the 100-m^2^
area source. For small downwind distance (50 m), difference of
approximately 10% was observed in all stability classes. For most other
distances a less than 10% difference was observed in all stability
classes.

**3.2 Release Rate Comparison**

To calculate the release rate, RESRAD-OFFSITE uses the average mass
loading, deposition velocity, average source concentration in the
primary contaminated area, and source area (see Section 2.2.6 in the
RESRAD-OFFSITE Manual \[Yu et al. 2007\]). MILDOS-AREA uses windblown
particle emissions to calculate release rate (depends on the wind speed,
resuspension rate, average concentration, source area, etc.; see Section
2.2).

In MILDOS-AREA, the source release rate is calculated using the
methodology described in Section 2.2. For a 100-m^2^ contaminated area,
1 pCi/g contamination, and wind speed of 10 mph, the source release rate
was 6186 pCi/yr.

In RESRAD-OFFSITE, the source release rate is calculated as follows:

*Source release rate (pCi/yr) = average source concentration in the
primary contaminated area (pCi/g) \* mass loading (g/m^3^) \* deposition
velocity (m/sec) \* primary contaminated area (m^2^) \* seconds in one
year*

For:

Source concentration = 1 pCi/g,

Mass loading = 1E-04 g/m^3^,

Deposition velocity = 0.01 m/sec, and

Primary contaminated area = 100 m^2^,

The source release rate = 1 \* \[1E-04 \* 0.01 \* 100 \* 3.154E+07\] =
3156 pCi/yr.

For the wind blowing at 10 mph, the release rate in the MILDOS-AREA code
was about 96% higher. The difference would be much higher for other wind
speeds, because in the RESRAD-OFFSITE code the source release rate does
not depend on the wind speed.

  ------------ ---------------- ---------- ---------------- ---------- ---------------- ------------ ---------------- ---------- ---------------- ---------- ---------------- ----------
  **TABLE 3.1                                                                                                                                                                 
  Chi/Q                                                                                                                                                                       
  Comparison                                                                                                                                                                  
  for Point                                                                                                                                                                   
  Source**                                                                                                                                                                    

               [Stability Class            [Stability Class            [Stability Class              [Stability Class            [Stability Class            [Stability Class 
               A]{.underline}              B]{.underline}              C]{.underline}                D]{.underline}              E]{.underline}              F]{.underline}   

  Receptor     MILDOS-AREA      OFFSITE    MILDOS-AREA      OFFSITE    MILDOS-AREA      OFFSITE      MILDOS-AREA      OFFSITE    MILDOS-AREA      OFFSITE    MILDOS-AREA      OFFSITE
  downwind                                                                                                                                                                    
  distance (m)                                                                                                                                                                

  56.6         8.77E-04         9.01E-04   1.13E-03         1.16E-03   1.59E-03         1.64E-03     2.47E-03         2.57E-03   3.12E-03         3.27E-03   4.43E-03         4.69E-03

  70.7         5.73E-04         5.83E-04   7.39E-04         7.53E-04   1.05E-03         1.07E-03     1.63E-03         1.67E-03   2.05E-03         2.13E-03   2.94E-03         3.08E-03

  99.0         3.00E-04         3.03E-04   3.89E-04         3.92E-04   5.52E-04         5.57E-04     8.61E-04         8.77E-04   1.09E-03         1.11E-03   1.57E-03         1.63E-03

  141.4        1.56E-04         1.56E-04   2.02E-04         2.02E-04   2.78E-04         0.000279\\   4.27E-04         4.31E-04   5.45E-04         5.55E-04   7.98E-04         8.22E-04

  707.1        4.99E-06         4.90E-06   7.73E-06         7.61E-06   1.25E-05         1.23E-05     2.12E-05         2.11E-05   2.84E-05         2.86E-05   3.88E-05         3.94E-05

  1,414        2.48E-06         2.43E-06   3.61E-06         3.53E-06   3.43E-06         3.38E-06     6.12E-06         6.11E-06   8.17E-06         8.21E-06   1.06E-05         1.09E-05

  7,071        4.65E-07         4.60E-07   6.53E-07         6.58E-07   6.21E-07         6.23E-07     5.41E-07         5.48E-07   5.48E-07         5.73E-07   6.75E-07         7.16E-07

  14,142       2.14E-07         2.25E-07   2.88E-07         3.10E-07   2.74E-07         2.90E-07     2.38E-07         2.51E-07   1.72E-07         2.16E-07   1.99E-07         2.27E-07
  ------------ ---------------- ---------- ---------------- ---------- ---------------- ------------ ---------------- ---------- ---------------- ---------- ---------------- ----------

+-----------------------------------------------------------------------+
| **TABLE 3.2 Chi/Q Comparison for Area Source**                        |
|                                                                       |
|   ---------- ---------------- ---------- -                            |
| --------------- ---------- ---------------- ---------- -------------- |
| -- ---------- ---------------- ---------- ---------------- ---------- |
|   Receptor   [Stability Class                                         |
|          [Stability Class            [Stability Class            [Sta |
| bility Class            [Stability Class            [Stability Class  |
|   downwind   A]{.underline}                                           |
|          B]{.underline}              C]{.underline}              D]{. |
| underline}              E]{.underline}              F]{.underline}    |
|   distance                                                            |
|                                                                       |
|                                                                       |
|   (m)                                                                 |
|                                                                       |
|                                                                       |
|                                                                       |
|              MILDOS-AREA      OFFSITE                                 |
|   MILDOS-AREA      OFFSITE    MILDOS-AREA      OFFSITE    MILDOS-AREA |
|       OFFSITE    MILDOS-AREA      OFFSITE    MILDOS-AREA      OFFSITE |
|                                                                       |
|   49.5       1.07E-03         1.18E-03                                |
|  1.37E-03         1.52E-03   1.93E-03         2.14E-03   2.99E-03     |
|      3.34E-03   3.78E-03         4.25E-03   5.33E-03         6.07E-03 |
|                                                                       |
|   63.6       6.78E-04         7.19E-04                                |
|  8.72E-04         9.27E-04   1.23E-03         1.31E-03   1.91E-03     |
|      2.05E-03   2.40E-03         2.62E-03   3.44E-03         3.77E-03 |
|                                                                       |
|   91.9       3.40E-04         3.50E-04                                |
|  4.40E-04         4.53E-04   6.24E-04         6.43E-04   9.72E-04     |
|      1.01E-03   1.23E-03         1.29E-03   1.77E-03         1.88E-03 |
|                                                                       |
|   134.4      1.77E-04         1.73E-04                                |
|  2.29E-04         2.22E-04   3.20E-04         3.08E-04   4.94E-04     |
|      4.77E-04   6.28E-04         6.13E-04   9.15E-04         9.07E-04 |
|                                                                       |
|   700        5.07E-06         4.95E-06                                |
|  8.43E-06         7.77E-06   1.32E-05         1.26E-05   2.22E-05     |
|      2.14E-05   2.98E-05         2.91E-05   4.08E-05         4.02E-05 |
|                                                                       |
|   1,407      2.49E-06         2.44E-06                                |
|  3.62E-06         3.55E-06   3.31E-06         3.37E-06   6.17E-06     |
|      6.16E-06   8.24E-06         8.28E-06   1.06E-05         1.09E-05 |
|                                                                       |
|   7,064      4.65E-07         4.60E-07                                |
|  6.54E-07         6.58E-07   6.22E-07         6.24E-07   5.42E-07     |
|      5.48E-07   5.50E-07         5.74E-07   6.77E-07         7.17E-07 |
|                                                                       |
|   14,135     2.17E-07         2.25E-07                                |
|  2.92E-07         3.11E-07   2.78E-07         2.90E-07   2.42E-07     |
|      2.51E-07   1.78E-07         2.16E-07   2.07E-07         2.27E-07 |
|   ---------- ---------------- ---------- -                            |
| --------------- ---------- ---------------- ---------- -------------- |
| -- ---------- ---------------- ---------- ---------------- ---------- |
+-----------------------------------------------------------------------+

**3.3 Air Inhalation Pathway Dose Calculations**

There are differences in both release rate (source term) and air
concentration calculations between the RESRAD-OFFSITE and MILDOS-AREA
codes. As a result, there are also differences in the air pathway dose
calculations of the codes.

In the MILDOS-AREA code the inhalation pathway doses are calculated from
the total annual average air concentration, that is, the sum of the
direct and the resuspended air concentrations. The RESRAD-OFFSITE code
does not include resuspension from the ground surface deposition in its
air inhalation pathway dose calculations.

For this comparison, a point source release at ground level of 1 mCi/yr
^238^U was assumed in the MILDOS-AREA code. The deposition velocity in
RESRAD-OFFSITE was changed to 0.01 m/sec to match the value in
MILDOS-AREA. To match the point source release from the MILDOS-AREA
code, the primary contamination (^238^U) was calculated in the
RESRAD-OFFSITE code as follows:

*Primary contamination (pCi/g) = point source release (mCi/yr)/\[mass
loading (g/m^3^) \* deposition velocity (m/sec) \* primary contaminated
area (m^2^) \* seconds in one year\]*

= 1 / \[1E-04 \* 0.01 \* 0.01 \* 3.154E+07\] = 3.17 mCi/g

The air concentration in MILDOS-AREA from two components --- direct
plume and resuspension from ground deposition --- was calculated (see
Table 3.3). The calculations were performed only for stability class A
at four different receptor locations. The air concentration in
RESRAD-OFFSITE matches the direct plume concentration in MILDOS-AREA.
However, the total air concentration in MILDOS-AREA is 60% higher
compared with RESRAD-OFFSITE after 5 years of continuous release and
deposition (see Table 3.3). The difference occurs because RESRAD-OFFSITE
does not include the resuspension from ground deposition.

**TABLE 3.3 Air Concentration Comparison**

+---------+-----------+-----------+--------+----------+--------------+
| D       | Air       |           |        |          | MILDOS-AREA/ |
| ownwind | conc      |           |        |          |              |
| d       | entration |           |        |          | RE           |
| istance | (         |           |        |          | SRAD-OFFSITE |
| (m)     | pCi/m^3^) |           |        |          | ratio        |
+---------+-----------+-----------+--------+----------+--------------+
|         | MI        |           |        | RESRAD-  |              |
|         | LDOS-AREA |           |        |          |              |
|         |           |           |        | OFFSITE  |              |
+---------+-----------+-----------+--------+----------+--------------+
|         | Direct    | Res       | Total  |          |              |
|         | plume     | uspension |        |          |              |
+---------+-----------+-----------+--------+----------+--------------+
| 56.6    | 2.78E-02  | 1.73E-02  | 4.     | 2.84E-02 | 1.59         |
|         |           |           | 51E-02 |          |              |
+---------+-----------+-----------+--------+----------+--------------+
| 70.7    | 1.82E-02  | 1.13E-02  | 2.     | 1.84E-02 | 1.60         |
|         |           |           | 95E-02 |          |              |
+---------+-----------+-----------+--------+----------+--------------+
| 99.0    | 9.52E-03  | 5.99E-03  | 1.     | 9.53E-03 | 1.62         |
|         |           |           | 55E-02 |          |              |
+---------+-----------+-----------+--------+----------+--------------+
| 141.4   | 4.95E-03  | 3.09E-03  | 8.     | 4.91E-03 | 1.64         |
|         |           |           | 04E-03 |          |              |
+---------+-----------+-----------+--------+----------+--------------+

In the MILDOS-AREA code, Equation 2.4-1 in NUREG/CR-2011 (Strenge and
Bander 1981) is used to calculate inhalation dose (see Section 2.5). The
doses are calculated for different organs as well as for the whole body.
It uses air concentration at receptor location and inhalation DCF
(mrem/yr per pCi/m^3^) in the dose calculations.

In the RESRAD-OFFSITE code, inhalation dose is calculated as described
in Section 6.2 of the RESRAD-OFFSITE Manual (Yu et al. 2007). It uses
dose conversion factor (mrem/pCi), occupancy and indoor filtration
factor, inhalation rate, and air concentration at the receptor location
to calculate inhalation dose. The default receptor inhalation rate is
8400 m^3^/yr.

MILDOS-AREA uses ^234^U and ^238^U in the same concentrations to
calculate inhalation dose (i.e., ^234^U is assumed to be in equilibrium
with ^238^U). The codes have different units for inhalation DCFs:
mrem/yr per pCi/m^3^ in MILDOS-AREA vs. mrem/pCi in RESRAD-OFFSITE. The
inhalation DCFs for ^238^U and ^234^U in the MILDOS code are 434 and 485
mrem/yr per pCi/m^3^, respectively. The inhalation DCF in RESRAD-OFFSITE
for ^238^U is 0.118 mrem/pCi. The MILDOS-AREA code uses
particle-size-dependent inhalation DCFs.

Table 3.4 compares the inhalation pathway doses for 100% occupancy at
four different receptor locations. The ^238^U release rate was the same
as in the air concentration comparison. The inhalation dose for ^238^U
in the MILDOS-AREA code was about 50% higher than in the RESRAD-OFFSITE
code.

> **TABLE 3.4 Inhalation Pathway Dose Comparison**

+-----------+----------------+------------------+---------------------+
| Receptor  | Inhalation     |                  | MILDOS-AREA/        |
| downwind  | pathway dose   |                  |                     |
| distance  | (mrem/yr)      |                  | RESRAD-OFFSITE      |
| (m)       |                |                  | ratio               |
+-----------+----------------+------------------+---------------------+
|           | MILDOS-AREA    | RESRAD-OFFSITE   |                     |
+-----------+----------------+------------------+---------------------+
| 56.6      | 41.5           | 28.2             | 1.47                |
+-----------+----------------+------------------+---------------------+
| 70.7      | 27.1           | 18.2             | 1.49                |
+-----------+----------------+------------------+---------------------+
| 99.0      | 14.2           | 9.44             | 1.50                |
+-----------+----------------+------------------+---------------------+
| 141.4     | 7.39           | 4.87             | 1.52                |
+-----------+----------------+------------------+---------------------+

> **3.4 Ground Deposition Surface Soil Concentrations at Offsite
> Locations**
>
> In the MILDOS-AREA code, the ground concentration due to accumulation
> in surface soil is calculated using Equation 2.3-1 from NUREG/CR-2011
> (see Section 2.3). For ground deposition, only the direct plume air
> concentration is used (see Figure 2.3-1 in NUREG/CR-2011). The ground
> concentration is assumed to increase from the constant deposition
> source terms and to decrease from environmental loss (downward
> migration in soil and chemical bonding). The environmental losses are
> described by a rate constant corresponding to a 50-year half-life.
> Resuspension is not treated as a loss term. Material deposited on the
> ground is assumed to contribute to external exposure and ingestion
> exposure from intake of contaminated food products (see Figure 2.3-1
> in NUREG/CR-2011).
>
> In RESRAD-OFFSITE, accumulation in offsite surface soil includes
> accumulation due to irrigation with contaminated water and deposition
> of contaminated dust. The concentration is assumed to change due to
> radiological transformation, mixing of soil in the surface layer,
> erosion of the surface layer, and equilibrium desorption release. It
> is assumed that contamination is volumetric in nature and is uniform
> within the soil mixing layer.
>
> For this comparison, in the RESRAD-OFFSITE code it was assumed there
> was no soil erosion (soil erodity factor was set at 0), irrigation
> water was not contaminated (irrigation rate was set at 0 m/yr), and
> uranium Kd = 4000 cm^3^/g. To convert volumetric contamination in
> RESRAD-OFFSITE to surface contamination in MILDOS-AREA, a soil mixing
> layer of 0.15 m and soil density of 1.6 g/cm^3^ were used in the
> RESRAD-OFFSITE code (see Table 3.5). The comparison was made for the
> same release rates as used before at four receptor locations and the
> resulting differences in ground deposition were within 5% (See Table
> 3.5).
>
> **TABLE 3.5 Ground Deposition Comparison**

+---------+-----------+---+---------------+--------+-------+---------+---+
| D       | MI        |   | R             |        |       |         |   |
| ownwind | LDOS-AREA |   | ESRAD-OFFSITE |        |       |         |   |
| d       |           |   |               |        |       |         |   |
| istance |           |   |               |        |       |         |   |
| (m)     |           |   |               |        |       |         |   |
+---------+-----------+---+---------------+--------+-------+---------+---+
|         | Surface   | V |               | D      | M     | Ef      |   |
|         | conc      | o |               | ensity | ixing | fective |   |
|         | entration | l |               | (g/    | layer | surface |   |
|         | (         | u |               | cm^3^) | (m)   | concen  |   |
|         | pCi/m^2^) | m |               |        |       | tration |   |
|         |           | e |               |        |       | (pC     |   |
|         |           | t |               |        |       | i/m^2^) |   |
|         |           | r |               |        |       |         |   |
|         |           | i |               |        |       |         |   |
|         |           | c |               |        |       |         |   |
|         |           | c |               |        |       |         |   |
|         |           | o |               |        |       |         |   |
|         |           | n |               |        |       |         |   |
|         |           | c |               |        |       |         |   |
|         |           | e |               |        |       |         |   |
|         |           | n |               |        |       |         |   |
|         |           | t |               |        |       |         |   |
|         |           | r |               |        |       |         |   |
|         |           | a |               |        |       |         |   |
|         |           | t |               |        |       |         |   |
|         |           | i |               |        |       |         |   |
|         |           | o |               |        |       |         |   |
|         |           | n |               |        |       |         |   |
|         |           |   |               |        |       |         |   |
|         |           | ( |               |        |       |         |   |
|         |           | p |               |        |       |         |   |
|         |           | C |               |        |       |         |   |
|         |           | i |               |        |       |         |   |
|         |           | / |               |        |       |         |   |
|         |           | g |               |        |       |         |   |
|         |           | ) |               |        |       |         |   |
+---------+-----------+---+---------------+--------+-------+---------+---+
| 56.6    | 4.24E+04  | 1 |               | 1.6    | 0.15  | 4       |   |
|         |           | . |               |        |       | .43E+04 |   |
|         |           | 8 |               |        |       |         |   |
|         |           | 5 |               |        |       |         |   |
|         |           | E |               |        |       |         |   |
|         |           | - |               |        |       |         |   |
|         |           | 0 |               |        |       |         |   |
|         |           | 1 |               |        |       |         |   |
+---------+-----------+---+---------------+--------+-------+---------+---+
| 70.7    | 2.77E+04  | 1 |               | 1.6    | 0.15  | 2       |   |
|         |           | . |               |        |       | .88E+04 |   |
|         |           | 2 |               |        |       |         |   |
|         |           | 0 |               |        |       |         |   |
|         |           | E |               |        |       |         |   |
|         |           | - |               |        |       |         |   |
|         |           | 0 |               |        |       |         |   |
|         |           | 1 |               |        |       |         |   |
+---------+-----------+---+---------------+--------+-------+---------+---+
| 99.0    | 1.45E+04  | 6 |               | 1.6    | 0.15  | 1       |   |
|         |           | . |               |        |       | .49E+04 |   |
|         |           | 2 |               |        |       |         |   |
|         |           | 2 |               |        |       |         |   |
|         |           | E |               |        |       |         |   |
|         |           | - |               |        |       |         |   |
|         |           | 0 |               |        |       |         |   |
|         |           | 2 |               |        |       |         |   |
+---------+-----------+---+---------------+--------+-------+---------+---+
| 141.4   | 7.55E+03  | 3 |               | 1.6    | 0.15  | 7       |   |
|         |           | . |               |        |       | .66E+03 |   |
|         |           | 1 |               |        |       |         |   |
|         |           | 9 |               |        |       |         |   |
|         |           | E |               |        |       |         |   |
|         |           | - |               |        |       |         |   |
|         |           | 0 |               |        |       |         |   |
|         |           | 2 |               |        |       |         |   |
+---------+-----------+---+---------------+--------+-------+---------+---+

**3.5 External Pathway Dose Calculations**

> The MILDOS-AREA code includes external doses from contaminated ground
> and air submersion pathways (see Figure 2.3-1 in NUREG/CR-2011
> \[Strenge and Bander 1981\]). An occupancy factor of 100% is assumed
> for external exposure pathways. A structural shielding factor of 0.825
> is used that accounts for indoor occupancy of 14 hours per day with a
> shielding factor of 0.7 (see Section 2.6).
>
> The direct external pathway dose from contaminated ground is the
> product of the ground contamination (pCi/m^2^), structural shielding
> factor, and dose conversion factor for surface contamination (mrem/yr
> per pCi/m^2^). The default external DCF for ^238^U is 3.70E-06 mrem/yr
> per pCi/m^2^. The air submersion pathway dose is the product of air
> concentration (pCi/m^3^), structural shielding factor, and air
> submersion DCF (mrem/yr per pCi/m^3^). The default air submersion DCF
> for ^238^U is 1.23E-04 mrem/yr per pCi/m^3^.
>
> The RESRAD-OFFSITE code does not include air submersion pathway dose.
> RESRAD‑OFFSITE calculates external dose in a manner consistent with
> RESRAD methodology (see Section 6.1 in the RESRAD-OFFSITE Manual \[Yu
> et al. 2007\]). The external pathway dose is the product of DCF for a
> volume source of infinite thickness and area (mrem/yr per pCi/g),
> radionuclide concentration in soil (pCi/g), occupancy and shielding
> factor, a cover and depth factor to account for finite thickness of
> contamination, and area and shape factor to account for finite area
> and shape of contamination. The default external DCF for ^238^U is
> 0.152 mrem/yr per pCi/g.
>
> Table 3.6 compares the external pathway doses. For this comparison,
> 100% outdoor occupancy is assumed in the RESRAD-OFFSITE code (receptor
> at the center of 100 m^2^ contaminated area). Table 3.6 includes the
> doses from contaminated ground and air submersion pathways. The air
> submersion pathway dose is much smaller (four orders of magnitude)
> compared with the direct external pathway dose. The RESRAD-OFFSITE
> code dose is much smaller but realistic compared with the MILDOS-AREA
> code. The inherent assumption in the MILDOS-AREA code is that there is
> no mixing of the contamination in the mixing layer and that the extent
> of contamination is infinite.
>
> **TABLE 3.6 External Pathway Dose Comparison**

<table>
<colgroup>
<col style="width: 17%" />
<col style="width: 3%" />
<col style="width: 11%" />
<col style="width: 24%" />
<col style="width: 2%" />
<col style="width: 0%" />
<col style="width: 2%" />
<col style="width: 11%" />
<col style="width: 21%" />
<col style="width: 3%" />
</colgroup>
<tbody>
<tr class="odd">
<td rowspan="2"><p>Receptor downwind distance</p>
<p>(m)</p></td>
<td></td>
<td colspan="2">Air submersion pathway dose (mrem/yr)</td>
<td colspan="2"></td>
<td></td>
<td colspan="2">Direct external pathway dose (mrem/yr)</td>
<td></td>
</tr>
<tr class="even">
<td colspan="2">MILDOS-AREA</td>
<td colspan="2"><p>RESRAD-</p>
<p>OFFSITE</p></td>
<td colspan="3">MILDOS-AREA</td>
<td colspan="2"><p>RESRAD-</p>
<p>OFFSITE</p></td>
</tr>
<tr class="odd">
<td>56.6</td>
<td colspan="2">4.58E-06</td>
<td colspan="2">Not included</td>
<td colspan="3">1.29E-01</td>
<td colspan="2">2.49E-03</td>
</tr>
<tr class="even">
<td>70.7</td>
<td colspan="2">2.99E-06</td>
<td colspan="2">Not included</td>
<td colspan="3">8.45E-02</td>
<td colspan="2">1.60E-03</td>
</tr>
<tr class="odd">
<td>99.0</td>
<td colspan="2">1.57E-06</td>
<td colspan="2">Not included</td>
<td colspan="3">4.43E-02</td>
<td colspan="2">8.34E-04</td>
</tr>
<tr class="even">
<td>141.4</td>
<td colspan="2">8.16E-07</td>
<td colspan="2">Not included</td>
<td colspan="3">2.30E-02</td>
<td colspan="2">4.27E-04</td>
</tr>
</tbody>
</table>

> **3.6 Plant Concentration Calculations**

In calculating radionuclide concentration in the edible part of the
plant, RESRAD-OFFSITE includes root uptake from contaminated soil,
foliar uptake from overhead irrigation, and foliar uptake of dust (see
Section 5.3 in the RESRAD-OFFSITE Manual \[Yu et al. 2007\]). The
MILDOS-AREA code includes root and foliar uptake of dust in calculating
plant concentration but does not include uptake from irrigation (see
Section 2.7).

To simulate the same root uptake in RESRAD-OFFSITE, it was assumed that
soil density = 1.6 g/cm^3^ and plow depth = 0.15 m. This results in plow
density of 240 kg/m^2^, as assumed in MILDOS-AREA.

There are five categories of plants in MILDOS-AREA: edible above-ground
vegetables, potatoes, other edible below-ground vegetables, pasture
grass, and hay. The edible above-ground vegetables, potatoes, and
below-ground vegetables are for human consumption and pasture grass and
hay are for animal consumption.

There are four categories of plants in RESRAD-OFFSITE: fruit, grain,
nonleafy vegetables; leafy vegetables; pasture and silage; and grain.
The fruit, grain, nonleafy vegetables and leafy vegetables are for human
consumption and pasture and silage and hay are for animal consumption.
Similar equations for root uptake and foliar uptake of dust are used in
both codes. However, the parameters used are different for different
food types.

Table 3.7 compares the parameters used in both codes for calculating
plant concentrations.

Four plant type concentrations --- above-ground, below-ground, pasture
grass, and hay --- were compared with RESRAD-OFFSITE for four plant
types --- leafy; fruit, grain, nonleafy; pasture and silage; and grain
--- respectively, by setting RESRAD-OFFSITE plant pathway parameters
similar to those in MILDOS-AREA. The following parameters in
RESRAD-OFFSITE were changed from their default values: soil density
(changed to 1.6 g/cm^3^ from 1.5 g/cm^3^), growing period for leafy
vegetables (changed to 60 days from 90 days), weathering constant
(changed to 18.07 from 20), deposition velocity (changed from 0.001 to
0.01 m/sec), foliar interception fraction (changed to 0.2 from 0.25),
and wet crop yield for all plant types.

**TABLE 3.7 Default Parameter Values in MILDOS-AREA and RESRAD-OFFSITE
Codes for Plant Concentration Calculations**

  ----------------------- ----------------------- -----------------------
  Parameter               MILDOS-AREA             RESRAD-OFFSITE

  Foliar deposition       1 -- above-ground,\     0.1 -- fruit, grain,
  fraction reaching       0.1 -- below-ground     and nonleafy
  edible portion                                  vegetables,\
                                                  1 -- leafy vegetables,
                                                  pasture and silage,
                                                  grain

  Wet crop yield, kg/m^2^ 2 -- all except pasture 0.7 -- fruit, grain,
                          grass,\                 and nonleafy
                          0.75 -- pasture grass   vegetables; grain;\
                                                  1.1 - pasture and
                                                  silage;\
                                                  1.5 -- leafy vegetables

  Foliar interception     0.2                     0.25
  fraction                                        

  Deposition velocity,    0.01                    0.001
  m/sec                                           

  Weathering constant,    equivalent to 14-day    20
  1/yr                    half-time               

  Growing period, d       60 -- all except        30 -- pasture and
                          pasture grass,\         silage;\
                          30 -- pasture grass     60 -- fruit, grain,
                                                  nonleafy vegetables;
                                                  grain;\
                                                  90 -- leafy vegetables

  Plowing density,        240                     Not used
  kg/m^2^                                         

  Density, g/cm^3^        Not used                1.6

  Plowing depth, m        Not used                0.15

  Soil to Plant transfer  2.5E-03                 2.5E-03
  coefficient (Biv),                              
  pCi/kg per pCi/kg                               
  ----------------------- ----------------------- -----------------------

In this comparison it was assumed that all plants types grow in the
agricultural area at 50 m in x-direction and 50 m in y-direction away
from the source release point. Table 3.8 compares the calculated plant
concentrations. For the MILDOS-AREA code, contributions from both root
uptake and foliar deposition are shown.

The contribution of root uptake to plant concentration was constant for
all plant types and was much smaller compared with foliar deposition.
The maximum percentage contribution of root uptake was in below-ground
plant types because the foliar deposition contribution is least for this
plant type. Pasture grass was most contaminated compared with other
plant types due to smaller crop yield. Table 3.8 shows that the plant
concentration was higher in the MILDOS-AREA code by about 60%, and the
difference is similar to the difference in air concentration (see Table
3.3).

**TABLE 3.8 Plant Concentration Comparison**

+-----------+---------+------------+-----+---+---------+---------------+
| Plant     | Plant   |            |     |   |         | MILDOS-AREA/\ |
| type      | concen  |            |     |   |         | OFFSITE\      |
|           | tration |            |     |   |         | ratio         |
|           | (       |            |     |   |         |               |
|           | pCi/kg) |            |     |   |         |               |
+-----------+---------+------------+-----+---+---------+---------------+
|           | MILD    |            |     |   | RESRAD- |               |
|           | OS-AREA |            |     |   |         |               |
|           |         |            |     |   | OFFSITE |               |
+-----------+---------+------------+-----+---+---------+---------------+
|           | Root    | Foliar     | To  |   |         |               |
|           | uptake  | deposition | tal |   |         |               |
+-----------+---------+------------+-----+---+---------+---------------+
| Abo       | 0.288   | 48.8       | 4   |   | 30.73   | 1.60          |
| ve-ground |         |            | 9.1 |   |         |               |
+-----------+---------+------------+-----+---+---------+---------------+
| Bel       | 0.288   | 4.88       | 5   |   | 3.34    | 1.55          |
| ow-ground |         |            | .17 |   |         |               |
+-----------+---------+------------+-----+---+---------+---------------+
| Pasture   | 0.288   | 106.1      | 10  |   | 66.5    | 1.60          |
| grass     |         |            | 6.4 |   |         |               |
+-----------+---------+------------+-----+---+---------+---------------+
| Hay       | 0.288   | 48.8       | 4   |   | 30.73   | 1.60          |
|           |         |            | 9.1 |   |         |               |
+-----------+---------+------------+-----+---+---------+---------------+

> **3.7 Meat and Milk Concentration Calculations**

In the MILDOS-AREA code it is assumed that meat and milk become
contaminated because of the ingestion by dairy cattle of contaminated
pasture grass and hay. The radionuclide concentration in meat and milk
is calculated from pasture grass and hay concentration using meat and
milk transfer factors by considering the animal's total intake and the
fraction satisfied by the two food types. Code users can change the food
diet fraction (see Section 2.7).

In RESRAD-OFFSITE it is assumed that ingestion of contaminated plants,
soil, and water all contribute to meat and milk contamination. The
radionuclide concentration in meat and milk is calculated using Equation
5.52 in the RESRAD-OFFSITE Manual (Yu et al. 2007). Table 3.9 lists the
default transfer factors and ingestion rates for meat and milk
concentration calculations in both codes.

**TABLE 3.9 Default Parameter Values in the MILDOS-AREA and
RESRAD-OFFSITE Codes for Meat and Milk Concentration Calculations**

  -------------------------------------------------- ------------- ----------------
  Parameter                                          MILDOS-AREA   RESRAD-OFFSITE

  Feed ingestion rate, kg/d                          50            NA

  Pasture grass feed fraction                        0.5           NA

  Hay feed fraction                                  0.5           NA

  Uranium meat transfer coefficient, pCi/kg per      3.4E-04       3.4E-04
  pCi/d ingested                                                   

  Uranium milk transfer coefficient, pCi/L per pCi/d 6.1E-04       6.0E-04
  ingested                                                         

  Beef cattle water ingestion, l/d                   NA            50

  Beef cattle pasture and silage ingestion, kg/d     NA            14

  Beef cattle grain ingestion, kg/d                  NA            54

  Beef cattle soil ingestion from pasture and        NA            0.1
  silage, kg/d                                                     

  Beef cattle soil ingestion from grain, kg/d        NA            0.4

  Dairy cow water ingestion, l/d                     NA            160

  Dairy cow pasture and silage ingestion, kg/d       NA            44

  Dairy cow grain ingestion, kg/d                    NA            11

  Dairy cow soil ingestion from pasture and silage,  NA            0.4
  kg/d                                                             

  Dairy cow soil ingestion from grain, kg/d          NA            0.1
  -------------------------------------------------- ------------- ----------------

Meat and milk concentrations in the MILDOS-AREA code were compared with
those in the RESRAD-OFFSITE code by setting RESRAD-OFFSITE meat and milk
concentration calculation parameters similar to MILDOS-AREA parameters.
The following parameters in RESRAD-OFFSITE were changed from their
default values: uranium milk transfer coefficient (changed to 6.1E-04
pCi/L per pCi/d ingested), beef cattle and dairy cow water ingestion
(changed to 0 to simulate no water ingestion), beef cattle and diary cow
soil ingestion from pasture and silage (changed to 0 to simulate no soil
ingestion), beef cattle and diary cow soil ingestion from grain (changed
to 0 to simulate no soil ingestion), beef cattle and dairy cow pasture
and silage ingestion (changed to 25 kg/d to simulate 50 kg/d ingestion
and feed fraction of 0.5), and beef cattle and dairy cow grain ingestion
(changed to 25 kg/d to simulate 50 kg/d ingestion and feed fraction of
0.5).

In this comparison it was assumed that all plant types grow in the
agricultural area at 50 m in x-direction and 50 m in y-direction away
from the source release point, and that the beef cattle and dairy cows
are at the same location. Table 3.10 compares the calculated meat and
milk concentrations. The table shows that the meat and milk
concentrations were higher in the MILDOS-AREA code by about 60%, and
that the difference is the same as the difference in plant concentration
(see pasture grass and hay concentration ratios).

> **TABLE 3.10 Comparison of Meat and Milk Concentrations**

  ---------------------------------- ------------- ---------------- ------------------
   Calculations compared             MILDOS-AREA   RESRAD-OFFSITE   MILDOS-AREA/\
                                                                    RESRAD-OFFSITE
                                                                    ratio

  Pasture grass concentration,       106.4         66.5             1.60
  pCi/kg                                                            

  Hay concentration, pCi/kg          49.1          30.73            1.60

  Meat concentration, pCi/kg         1.32          0.8264           1.60

  Milk concentration, pCi/L          2.37          1.483            1.60
  ---------------------------------- ------------- ---------------- ------------------

8.  **Ingestion Pathway Dose Calculations**

> In the MILDOS-AREA code, first the annual radionuclide intake by
> ingestion is calculated using ingestion rates of different food types
> by receptor age group, and activity concentration in the food type
> (see Section 2.7). For plant ingestion it is assumed that 50% of the
> activity remains after food preparation. The radionuclide intake is
> multiplied by ingestion DCFs to calculate the ingestion pathway doses.
> Table 3.11 lists the default ingestion rates used in the code for an
> adult member of the public. For the plant ingestion pathway, total
> vegetable ingestion rate is provided along with the different
> vegetable type fractions consumed.
>
> In the RESRAD-OFFSITE code, the ingestion pathway dose is calculated
> as the product of the ingestion DCF, ingestion rate of different
> foods, fraction of the food that was obtained from the contaminated
> area, and the concentration of the radionuclide in the food (see
> Section 6.4 in the RESRAD-OFFSITE Manual \[Yu et al. 2007\]). Table
> 3.11 lists the default parameters used in ingestion pathway dose
> calculations.

Plant, meat, and milk ingestion pathway doses in the MILDOS-AREA code
were compared with those in the RESRAD-OFFSITE code by setting
RESRAD-OFFSITE ingestion parameters similar to MILDOS-AREA parameters.
The following parameters in RESRAD-OFFSITE were changed from their
default values: fruit, grain, and nonleafy vegetables (changed to 65.31
kg/yr to simulate potatoes and below-ground vegetable ingestion in
MILDOS-AREA), leafy vegetable ingestion (changed to 39.69 to simulate
above-ground vegetable ingestion in MILDOS), meat ingestion (changed to
78.3 kg/yr), milk ingestion (changed to 130 kg/yr), soil ingestion
(changed to 0 to simulate no soil ingestion in MILDOS-AREA), and water
ingestion (changed to 0 to simulate no water ingestion in MILDOS-AREA).

In this comparison it was assumed that all plant types grow in the
agricultural area at 50 m in x-direction and 50 m in y-direction away
from the source release point, and that the beef cattle and dairy cows
are at the same location. Table 3.12 compares the calculated plant, meat
and milk ingestion pathway doses. The table shows that the meat and milk
ingestion doses were higher in MILDOS-AREA by a factor of about 3.3.
This difference is equal to the difference in the food concentration
multiplied by the difference in DCF (MILDOS-AREA assumes ^238^U and
^234^U are at the same concentration, and includes the doses from both
^238^U and ^234^U).

> **TABLE 3.11 Default Parameters for Ingestion Pathways in the
> MILDOS-AREA and RESRAD-OFFSITE Codes for an Adult Member of the
> Public**

  --------------------------------- ------------------ ------------------
  Parameter                         MILDOS-AREA        RESRAD-OFFSITE

  Fruit, grain, and nonleafy        NA                 160
  vegetables ingestion, kg/yr                          

  Leafy vegetables ingestion, kg/yr NA                 14

  Vegetables, kg/yr                 105                NA

  Above-ground vegetables fraction  0.378              NA

  Potatoes fraction                 0.573              NA

  Below-ground vegetables fraction  0.049              NA

  Meat ingestion, kg/yr             78.3               63

  Milk ingestion, kg/yr             130                92

  Soil ingestion, kg/yr             NA                 36.5

  Water ingestion, L/yr             NA                 510

  Fraction from affected area --    NA                 0.5
  fruit, grain, and nonleafy                           
  vegetables                                           

  Fraction from affected area --    NA                 0.5
  leafy vegetables                                     

  Fraction from affected area --    NA                 1
  meat                                                 

  Fraction from affected area --    NA                 1
  milk                                                 

  Fraction from affected area --    NA                 1
  drinking water                                       

  Activity remaining after food     0.5                NA
  preparation -- plants                                

  Activity remaining after food     1                  NA
  preparation -- meat and milk                         

  ^238^U Ingestion DCF, mrem/pCi    2.55E-04           2.55E-04

  ^234^U ingestion DCF, mrem/pCi    2.84E-04           2.83E-04
  --------------------------------- ------------------ ------------------

**TABLE 3.12 Comparison of Ingestion Pathway Doses**

  --------------- -------------- ------------------ ---------------------
  Pathway         MILDOS-AREA    RESRAD-OFFSITE     MILDOS-AREA/\
                                                    RESRAD-OFFSITE ratio

  Plant ingestion 6.33E-01       1.94E-01           3.26

  Meat ingestion  5.71E-02       1.74E-02           3.28

  Milk ingestion  1.70E-01       5.18E-02           3.28
  --------------- -------------- ------------------ ---------------------

> **3.9 Main Differences in MILDOS-AREA and RESRAD-OFFSITE**

-   Dose Outputs: Population doses and organ doses are not included in
    the RESRAD-OFFSITE code.

-   Different Default Values:

    -   The codes use different default DCFs and consumption rates.

    -   MILDOS-AREA assumes ^234^U is in equilibrium with ^238^U.

-   Differences in Release, Dispersion, and Deposition Models:

    -   In RESRAD-OFFSITE, both dry deposition and wet deposition are
        considered, whereas only dry deposition is considered in
        MILDOS-AREA.

    -   RESRAD-OFFSITE uses the average mass loading, deposition
        velocity, average concentration, and source area to calculate
        the source term (release rate), whereas MILDOS-AREA uses
        windblown particle emission to calculate the source term.

    -   The RESRAD-OFFSITE code does not include resuspension from
        ground surface deposition in air concentration calculations.

    -   In RESRAD-OFFSITE, accumulation in offsite surface soil includes
        accumulation due both to irrigation with contaminated water and
        to deposition of contaminated dust, whereas only deposition of
        contaminated dust is included in MILDOS-AREA.

    -   In RESRAD-OFFSITE, the soil concentration is affected by mixing
        in the surface layer, erosion, and leaching, whereas in
        MILDOS-AREA, it is affected by the constant deposition and
        environmental loss.

    -   RESRAD-OFFSITE calculates the average air and soil
        concentrations from deposition for different selected areas,
        whereas MILDOS-AREA calculates air concentration and ground
        deposition at a specified receptor location (no area
        associated).

```{=html}
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-   Differences in Exposure Pathways:

    -   The RESRAD-OFFSITE code does not include air submersion pathway
        dose.

    -   External pathway dose in MILDOS-AREA is calculated by assuming
        infinite surface source, whereas RESRAD-OFFSITE calculates it by
        assuming a finite volume source with uniform concentration
        within the mixing layer.

    ```{=html}
    <!-- -->
    ```
    -   In calculating radionuclide concentration in the edible part of
        the plant, RESRAD-OFFSITE includes root uptake from contaminated
        soil, foliar uptake from overhead irrigation, and foliar uptake
        of dust; MILDOS-AREA does not include uptake from irrigation.

    -   There are five categories of plants in MILDOS-AREA: edible
        above-ground vegetables, potatoes, other edible below-ground
        vegetables, pasture grass, and hay. The edible above-ground
        vegetables, potatoes, and below-ground vegetables are for human
        consumption, and pasture grass and hay are for animal
        consumption. There are four categories of plants in
        RESRAD-OFFSITE: fruit, grain, nonleafy vegetables; leafy
        vegetables; pasture and silage; and grain. The fruit, grain,
        nonleafy vegetables and leafy vegetables are for human
        consumption, and pasture and silage and hay are for animal
        consumption.

    -   In RESRAD-OFFSITE, it is assumed that ingestion of contaminated
        plants, soil, and water all contribute to meat and milk
        contamination. In MILDOS-AREA, contaminated soil and water
        ingestion is not included.

**4 Verification of the Source Term Derivation and Integration of the
in‑situ leaching SourceS with THE MILDOS-Area code**

The sources of radioactive effluent from an operating ISL uranium
recovery facility include: (1) drilling operations at new well fields,
(2) uranium extraction operations at production well fields, (3) drying
and packaging of yellow cake, (4) restoration operations at old well
fields, and (5) land application area (Faillace et al. 1997). The
operating ISL facility may have all five of these source types. This
verification included the source term derivation in the new well field,
yellow cake drying and packaging, restoration well field, production
well field, and land application source types. The following
calculations were verified:

New Well Field:

-   ^222^Rn release rate

-   Average flux calculation

Yellow Cake Drying and Packaging:

-   Stack release rate

Restoration Well Field:

-   Radon source

-   ^222^Rn concentration in the circulating water

-   ^222^Rn release rate from purge water into settling pond

-   ^222^Rn release rate from gas venting and leaking during circulation

-   Total ^222^Rn release rate from restoration well field

Production Well Field:

-   Radon source

-   Water discharge from resin unloading

-   ^222^Rn concentration in the process water

-   ^222^Rn release from purge water

-   ^222^Rn release from venting

-   ^222^Rn release from unloading of IX column content

-   Total radon release

Land Application Area:

-   Retardation coefficient

-   Fractional retention in surface water

-   Radionuclide concentration in surface water

-   Radon flux and radionuclide release rate

The equations used in the calculations were taken from Faillace et al.
(1997) or NUREG‑1569 (NRC 2003). The verification results are provided
in Table 4.1. First, the common input parameters for the sample ISL
facility are listed in Section 4.1.1, with the user-changeable
parameters highlighted in yellow. Each subsequent section contains a
table with the input parameters for the specific source along with the
equations used in the calculations.

To ensure that these values displayed in the user interface were
actually used in the MILDOS-AREA code, the calculated doses were
compared with the MILDOS-AREA results for the same ^222^Rn and
radionuclide releases. The comparisons are shown in Tables 4.2 through
4.6.

**4.1 Verification of the ISL Source Term Derivation**

**4.1.1 Common ISL Facility Input Parameters**

  ------------------------- ------------------------------------ --------------
  ***Input parameter:***    ***Description:***                   ***Value:***

  Ra_ore                    Concentration of radium in ore       280
                            (pCi/g)                              

  P                         Bulk density of ore material         1.80E+00
                            (g/cm^3^)                            

  Porosity                  Ore porosity                         2.80E-01

  Ci_pCi                    Unit conversion factor (Ci/pCi)      1.00E-12

  L --                      Decay constant of ^222^Rn (/d)       0.181

  s_yr                      Unit conversion factor (sec/yr)      3.15E+07

  pCi_Ci                    Unit conversion factor (pCi/Ci)      1.00E+12

  cm^3^\_m^3^               Unit conversion factor               1.00E+06

  Ci_pCi_d_yr               Unit conversion (Ci/pCi) (d/yr)      3.65E-10

  g-MT                      Unit conversion factor               1.00E+06

  YCPR                      Yellow cake (U~3~O~8~) production    520
                            rate (MT/yr)                         

  U-nat-per-g-of-U~3~O~8~   Natural uranium in 1 g of U~3~O~8~   0.85
  (g)                                                            

  U-238-per-g-of-U-nat (Ci) ^238^U activity in 1 g of natural    3.30E-07
                            uranium                              

  L_m^3^                    Unit conversion factor (L/m^3^)      1.00E+03

  days_per_year             Unit conversion factor (d/yr)        3.65E+02

  L_cm^3^                   Unit conversion factor (L/cm^3^)     1.00E-03
  ------------------------- ------------------------------------ --------------

**4.1.2 New Well Field -- ^222^Rn Release Rate and Average Flux
Calculations**

For ^222^Rn release rate calculations, Equation 1 from Faillace et al.
(1997) is used. ***Input parameters***

  --------------------------------------------------------- -------------
  ***Input parameters:***                                   

  E -- emanating power                                      0.25

  T -- storage time in mud pit (d)                          12

  M -- average mass of ore material in the pit (g)          3.50E+06

  N -- number of mud pits generated per year (/yr)          50

  A -- area of active drilling per year (m^2^)              60000
  --------------------------------------------------------- -------------

> **Rn_nw =** ^222^Rn **release rate from new well field (Ci/yr)**  
>
>  
>
> Rn_nw = 10^-12^ \* E \* L \* Ra_ore \* T \* M \* N  
>
>    
>
> 2.66E-02 = 1E-12 \* 0.25 \* 0.181 \* 280 \* 12 \* 3500000 \* 50  
>
> Rn_nw Ci_pCi E L Ra_ore T M N  
>
> (Ci/yr)   (Ci/pCi)       (/d)   (pCi/g)   (d)   (g) (/yr)  
>
> **Rn_flux = Average ^222^Rn flux rate (pCi/m^2^/s) from new well
> field**
>
>    
>
> Rn_flux = (10^12^ \* Rn_nw) / (A \* s_yr)  
>
>    
>
> 1.41E-02 = ( 1E+12 \* 0.02661 ) / ( 60000 \* 3.2E+07 )
>
> Rn_flux pCi_Ci Rn_nw A s_yr  
>
> (pCi/m^2^/sec)     (pCi/Ci)   (Ci/yr)       (m^2^)   (sec/yr)  

<table>
<colgroup>
<col style="width: 0%" />
<col style="width: 3%" />
<col style="width: 1%" />
<col style="width: 3%" />
<col style="width: 1%" />
<col style="width: 2%" />
<col style="width: 1%" />
<col style="width: 2%" />
<col style="width: 1%" />
<col style="width: 3%" />
<col style="width: 3%" />
<col style="width: 4%" />
<col style="width: 4%" />
<col style="width: 0%" />
<col style="width: 0%" />
<col style="width: 1%" />
<col style="width: 1%" />
<col style="width: 23%" />
<col style="width: 3%" />
<col style="width: 3%" />
<col style="width: 3%" />
<col style="width: 2%" />
<col style="width: 3%" />
<col style="width: 2%" />
<col style="width: 1%" />
<col style="width: 3%" />
<col style="width: 2%" />
<col style="width: 2%" />
<col style="width: 2%" />
<col style="width: 2%" />
<col style="width: 2%" />
<col style="width: 2%" />
<col style="width: 1%" />
</colgroup>
<tbody>
<tr class="odd">
<td></td>
<td colspan="17"><p><strong>4.1.3 Yellow Cake Drying and
Packaging</strong></p>
<p>For stack release rate calculations from yellow cake drying and
packaging, see Section 5.7 in</p>
<p>Faillace et al. (1997).</p>
<table>
<colgroup>
<col style="width: 87%" />
<col style="width: 12%" />
</colgroup>
<tbody>
<tr class="odd">
<td><em><strong>Input parameters:</strong></em></td>
<td></td>
</tr>
<tr class="even">
<td><sup>238</sup>U-particulate-release-fraction-to-stack</td>
<td>0.001</td>
</tr>
<tr class="odd">
<td>Thorium-activity-fraction</td>
<td>0.005</td>
</tr>
<tr class="even">
<td>Radium-activity-fraction</td>
<td>0.005</td>
</tr>
<tr class="odd">
<td>Lead-polonium-other-decay-progeny-activity-fraction</td>
<td>0.005</td>
</tr>
</tbody>
</table>
<table>
<colgroup>
<col style="width: 17%" />
<col style="width: 3%" />
<col style="width: 8%" />
<col style="width: 3%" />
<col style="width: 20%" />
<col style="width: 4%" />
<col style="width: 9%" />
<col style="width: 4%" />
<col style="width: 12%" />
<col style="width: 3%" />
<col style="width: 10%" />
<col style="width: 2%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="11"><em><strong>Stack release rate calculations for Yellow
Cake Drying and Packaging</strong></em></td>
<td></td>
</tr>
<tr class="even">
<td colspan="11"><sup>238</sup>U Stack release rate (Ci/yr) = YCPR *
U-238-particulate-release-fraction-to-stack*U-nat-per-g-of-U3O8*<sup>238</sup>U
-per-f-of-U-nat*g-MT </td>
<td> </td>
</tr>
<tr class="odd">
<td> </td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td> </td>
</tr>
<tr class="even">
<td>1.46E-01</td>
<td>=</td>
<td>520</td>
<td>*</td>
<td>0.001</td>
<td>*</td>
<td>0.85</td>
<td>*</td>
<td>3.30E-07</td>
<td>*</td>
<td>1.00E+06</td>
<td> </td>
</tr>
<tr class="odd">
<td><sup>238</sup>U Stack release rate (Ci/yr)</td>
<td></td>
<td>YCPR<br />
(MT/yr)</td>
<td></td>
<td>U-238-particulate-release-fraction-to-stack</td>
<td></td>
<td>U-nat-per-g-of-U<sub>3</sub>O<sub>8</sub></td>
<td></td>
<td>U-238-per-g-of-U-nat (Ci)</td>
<td></td>
<td>g/MT</td>
<td> </td>
</tr>
<tr class="even">
<td></td>
<td> </td>
<td></td>
<td> </td>
<td> </td>
<td> </td>
<td>(g)</td>
<td> </td>
<td></td>
<td> </td>
<td> </td>
<td> </td>
</tr>
</tbody>
</table>
<table style="width:100%;">
<colgroup>
<col style="width: 22%" />
<col style="width: 2%" />
<col style="width: 1%" />
<col style="width: 2%" />
<col style="width: 19%" />
<col style="width: 3%" />
<col style="width: 0%" />
<col style="width: 4%" />
<col style="width: 21%" />
<col style="width: 3%" />
<col style="width: 3%" />
<col style="width: 3%" />
<col style="width: 1%" />
<col style="width: 3%" />
<col style="width: 4%" />
<col style="width: 2%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="12"><sup>230</sup>Th Stack release rate = <sup>238</sup>U
Stack release rate * thorium-activity-fraction</td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td colspan="2"> </td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td> </td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="2">7.29E-04</td>
<td colspan="2">=</td>
<td colspan="3">1.46E-01</td>
<td>*</td>
<td colspan="3">0.005</td>
<td> </td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td colspan="2"><sup>230</sup>Th Stack release rate</td>
<td colspan="2"></td>
<td colspan="3"><sup>238</sup>U Stack release rate</td>
<td></td>
<td colspan="3">Thorium_activity_fraction</td>
<td> </td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="2">(Ci/yr)</td>
<td colspan="2"> </td>
<td colspan="3">(Ci/yr)</td>
<td> </td>
<td colspan="3"> </td>
<td> </td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="10"><sup>226</sup>Ra Stack release rate = <sup>238</sup>U
Stack release rate * radium-activity-fraction </td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td></td>
<td colspan="2"></td>
<td colspan="2"></td>
<td></td>
<td colspan="3"></td>
<td> </td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>7.29E-04</td>
<td colspan="2">=</td>
<td colspan="2">1.46E-01</td>
<td>*</td>
<td colspan="3">0.005</td>
<td> </td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td><sup>226</sup>Ra Stack release rate</td>
<td colspan="2"></td>
<td colspan="2"><sup>238</sup>U Stack release rate</td>
<td></td>
<td colspan="3">radium_activity_fraction</td>
<td> </td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td>(Ci/yr)</td>
<td colspan="2"> </td>
<td colspan="2">(Ci/yr)</td>
<td> </td>
<td colspan="3"> </td>
<td> </td>
<td colspan="3"></td>
<td></td>
<td colspan="2"></td>
</tr>
</tbody>
</table>
<table>
<colgroup>
<col style="width: 16%" />
<col style="width: 3%" />
<col style="width: 15%" />
<col style="width: 4%" />
<col style="width: 51%" />
<col style="width: 2%" />
<col style="width: 0%" />
<col style="width: 5%" />
</colgroup>
<tbody>
<tr class="odd">
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="8"><p>Lead polonium other decay progeny</p>
<p>Stack release rate = <sup>238</sup>U Stack release rate *
lead-polonium-other-decay-progeny-activity-fraction</p></td>
</tr>
<tr class="odd">
<td> </td>
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"></td>
<td> </td>
</tr>
<tr class="even">
<td>7.29E-04</td>
<td>=</td>
<td>1.46E-01</td>
<td>*</td>
<td>0.005</td>
<td colspan="2"></td>
<td> </td>
</tr>
<tr class="odd">
<td>Lead polonium other decay progeny Stack release rate</td>
<td></td>
<td><sup>238</sup>U Stack release rate (Ci/yr)</td>
<td></td>
<td>lead_polonium_other_decay_progeny_activity_fraction</td>
<td colspan="2"></td>
<td> </td>
</tr>
<tr class="even">
<td>(Ci/yr)</td>
<td> </td>
<td></td>
<td> </td>
<td> </td>
<td colspan="2"> </td>
<td> </td>
</tr>
</tbody>
</table>
<blockquote>
<p><strong>4.1.4 Restoration Well Field</strong></p>
</blockquote>
<table>
<colgroup>
<col style="width: 85%" />
<col style="width: 14%" />
</colgroup>
<tbody>
<tr class="odd">
<td><em><strong>Input parameters:</strong></em></td>
<td></td>
</tr>
<tr class="even">
<td>ODPY – operating days per year (d)</td>
<td>240</td>
</tr>
<tr class="odd">
<td>ARPY – area restored per year (m<sup>2</sup>)</td>
<td>100,000</td>
</tr>
<tr class="even">
<td>Ore_thickness (m)</td>
<td>5</td>
</tr>
<tr class="odd">
<td>TTWPR – total treated water purge rate (L/d)</td>
<td>1.10E+06</td>
</tr>
<tr class="even">
<td>FRSCCW – fraction of radon source carried by circulating water</td>
<td>0.8</td>
</tr>
<tr class="odd">
<td>RRVC – rate of radon venting during circulation (/d)</td>
<td>0.01</td>
</tr>
<tr class="even">
<td>TFVCWF – total flow volume in circulation in well field (L)</td>
<td>1.4E+08</td>
</tr>
</tbody>
</table></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr class="even">
<td colspan="13"><em><strong>Radon source</strong></em></td>
<td colspan="2"></td>
<td></td>
<td></td>
<td colspan="16"></td>
</tr>
<tr class="odd">
<td colspan="14">S - radon source (pCi/d)</td>
<td colspan="19"></td>
</tr>
<tr class="even">
<td colspan="14">S = 10<sup>6</sup> * L * E * Ra_ore* ARPY *
ore_thickness * P</td>
<td colspan="19"></td>
</tr>
<tr class="odd">
<td colspan="2"> </td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="2"></td>
<td colspan="19"></td>
</tr>
<tr class="even">
<td colspan="2">1.14E+13</td>
<td>=</td>
<td>1000000</td>
<td>*</td>
<td>0.181</td>
<td>*</td>
<td>0.25</td>
<td>*</td>
<td>280</td>
<td>*</td>
<td>100000</td>
<td colspan="2">*</td>
<td colspan="19"></td>
</tr>
<tr class="odd">
<td colspan="2">S</td>
<td></td>
<td>cm3_m3</td>
<td></td>
<td>L (/d)</td>
<td></td>
<td>E</td>
<td></td>
<td>Ra_ore</td>
<td></td>
<td>ARPY(m<sup>2</sup>)</td>
<td colspan="2"></td>
<td colspan="19"></td>
</tr>
<tr class="even">
<td colspan="2">pCi/d</td>
<td></td>
<td>(cm<sup>3</sup>/m<sup>3</sup>)</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>(pCi/g)</td>
<td></td>
<td></td>
<td colspan="2"></td>
<td colspan="19"></td>
</tr>
<tr class="odd">
<td colspan="2"> </td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>1.8</td>
<td>*</td>
<td colspan="2">5</td>
<td colspan="19"></td>
</tr>
<tr class="even">
<td colspan="2"> </td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>P</td>
<td></td>
<td colspan="2">ore_thickness</td>
<td colspan="19"></td>
</tr>
<tr class="odd">
<td colspan="2"> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>(g/cm<sup>3</sup>)</td>
<td> </td>
<td colspan="2">(m)</td>
<td colspan="19"></td>
</tr>
</tbody>
</table>

  -------------------- --- --- ---------- --------- -------- --------- ---- ---- ------ ------- ---
  ***CRn =* ^222^Rn                                                                             
  *concentration in                                                                             
  the circulating                                                                               
  water under                                                                                   
  steady-state                                                                                  
  condition (pCi/L)***                                                                          

  C~Rn~ = (S \*                                                                                  
  FRSCCW)/\[(L+RRVC)                                                                            
  \* TRVCWF +                                                                                   
  TTWPR\]                                                                                       

                                                                                                 

  3.28E+05             =   (   1.14E+13   \*        0.8      )         /    \[   (      0.181    

  C~Rn~                        S                    FRSCCW                              L        

  (pCi/L)                      (pCi/d)                                                  (/d)     

                               (          1100000   \+       4.2E+07   \*   (    0.01   \+       

                                          TTWPR              TFVCWF              RRVC            

                                          (L/d)              \(L\)               (/d)            
  -------------------- --- --- ---------- --------- -------- --------- ---- ---- ------ ------- ---

  ---------------- --- ---------------- ---- ---------- --- ---------- ---- ---- --------- ---------- ---- ------ -- --- -- --------------- -- -- --- ---- -- ------ --
  ***Rnw --                                                                                                                                                          
  ^222^Rn release                                                                                                                                                    
  rate from purge                                                                                                                                                    
  water into                                                                                                                                                         
  settling pond                                                                                                                                                      
  (Ci/yr)***                                                                                                                                                         

  Rn~w\ =~                                                                                                                                                           
  3.65E-10 \*                                                                                                                                                        
  C~Rn~ \* TTWPR                                                                                                                                                     
  \* ODPY /                                                                                                                                                          
  days_per_year                                                                                                                                                      

                                                                                                                                                                     

  8.65E+01         =   3.65E-10         \*   3.28E+05                  \*        1100000              \*   240       /      365                                      

  Rn~w~                Ci_pCi_d_yr           C~Rn~                               TTWPR                     d/yr             days_per_year                            

  (Ci/yr)              (Ci/pCi)(d/yr)        (pCi/L)                             (L/d)                                      (d/yr)                                   

                                                                                                                                                                     

  ***Rnv -- --                                                                                                                                                       
  ^222^Rn release                                                                                                                                                    
  rate from gas                                                                                                                                                      
  venting and                                                                                                                                                        
  leaking during                                                                                                                                                     
  circulation                                                                                                                                                        
  (Ci/yr)***                                                                                                                                                         

  Rnv ~=~ 3.65E-10                                                                                                                                                   
  \* C~Rn~ \*                                                                                                                                                        
  TFVCWF \*RRVC\*                                                                                                                                                    
  ODPY /                                                                                                                                                             
  days_per_year                                                                                                                                                      

                                                                                                                                                                     

  1.10E+02         =   3.65E-10         \*   3.28E+05                  \*        1.4E+08              \*   240       /      365                       \*      0.01   

  Rn~v~                Ci_pCi_d_yr           C~Rn~                               TFVCWF                    d                days_per_year                     RRVC   

  (Ci/yr)              (Ci/pCi)(d/yr)        (pCi/L)                             (L/d)                                      \(d\)                             (/d)   

                                                                                                                                                                     

  ***Total amount                                                                                                                                                    
  of -- ^222^Rn                                                                                                                                                      
  released from                                                                                                                                                      
  Restoration Well                                                                                                                                                   
  Field = Rnw +                                                                                                                                                      
  Rnv***                                                                                                                                                             

                                                                                                                                                                     

  1.97E+02                                              =   8.65E+01        \+             1.10E+02                                                                  

  Total ^222^Rn                                             Rn~w\                          Rnv\                                                                      
  released from                                             ~(Ci/yr)                       (Ci/yr)                                                                   
  restoration well                                                                                                                                                   
  field                                                                                                                                                              

  (Ci/yr)                                                                                                                                                            
  ---------------- --- ---------------- ---- ---------- --- ---------- ---- ---- --------- ---------- ---- ------ -- --- -- --------------- -- -- --- ---- -- ------ --

> **4.1.5 Production Well Field**

  ------------------------------------------------------------- ----------
                                                                

  ***Input parameters:***                                       

  PA -- Peak area per year to be mined                          5.00E+04

  V -- Volume of water in circulation (m^3^)                    4.20E+07

  f_radon_w -- fraction of radon source carried by circulating  8.00E-01
  water                                                         

  D -- average thickness of ore zone (m)                        3.00E+00

  v -- rate of radon venting from piping and valves during      1.00E-02
  circulation (/d)                                              

  Fp -- purge rate of treated water (L/d)                       5.50E+05

  Vi -- volume content of IX column (L)                         1.32E+04

  Ni -- number of IX column unloadings per day (/d)             3.00E+00

  Pi -- porosity of resin material                              4.00E-01
  ------------------------------------------------------------- ----------

  ----------- --- -------------- ---- ------- ---- ------ ---- --------- ---- -------- ---- ------- ---- -----------
  ***Radon                                                                                               
  source***                                                                                              

  S - radon                                                                                               
  source                                                                                                 
  (pCi/d)                                                                                                

  S = 10^6^                                                                                              
  \* L \* E                                                                                              
  \* Ra_ore\*                                                                                            
  PA \* D \*                                                                                             
  P                                                                                                      

                                                                                                          

  3.42E+12    =   1000000        \*   0.181   \*   0.25   \*   280       \*   50000    \*   3       \*   1.8

  S               cm3_m3              L            E           Ra_ore         50000         3            1.8

  pCi/d           (cm^3^/m^3^)        (/d)                     (pCi/g)        (m^2^)        \(m\)        (g/cm^3^)

                                                                                                          
  ----------- --- -------------- ---- ------- ---- ------ ---- --------- ---- -------- ---- ------- ---- -----------

  ---------------- ----- ------------ ---- --------- ------- --------- ---- ------- ----- --------
  ***Fi -- water                                                                          
  discharge from                                                                          
  resin unloading                                                                         
  of IX columns                                                                           
  (L/d)***                                                                                

  Fi = Ni \* Vi \*                                                                         
  Pi                                                                                      

                                                                                          

  15840            =     3            \*             13200             \*           0.4   

  Fi (L/d)               Ni (/d)                     Vi (L)                         Pi    

                                                                                          
  ---------------- ----- ------------ ---- --------- ------- --------- ---- ------- ----- --------

  -------------------- --- --- ---------- ---- ----------- --- --- ---- ---- ------- ---- ----------------------- ---- -------
  ***CRn = -- ^222^Rn                                                                                                  
  concentration in the                                                                                                 
  process water under                                                                                                  
  steady-state                                                                                                         
  condition (pCi/L)***                                                                                                 

  C~Rn~ = (S \*                                                                                                        
  f_radon_w)/\[(L+v)                                                                                                   
  \* V + Fp + Fi\]                                                                                                     

                                                                                                                        

  3.19E+05             =   (   3.42E+12   \*   0.8         )   /   \[   (    0.181   \+   0.01                    )    \*

  C~Rn~                        S               f_radon_w                     L            rate_of_radon_venting         

  (pCi/L)                      (pCi/d)                                       (/d)         (/d)                          

                                                                        \[   15840   \+   550000                  \+   4E+07

                                                                             Fi           Fp (L/d)                     V (L)
                                                                             (L/d)                                     
  -------------------- --- --- ---------- ---- ----------- --- --- ---- ---- ------- ---- ----------------------- ---- -------

  ----------------------- --- ---------------- ---- ----------------- ------ --------
  ***Rnw -- -- ^222^Rn                                                       
  release rate from purge                                                    
  water (Ci/yr)***                                                           

  Rn~w\ =~ 3.65E-10 \*                                                        
  C~Rn~ \* Fp                                                                

                                                                              

  6.40E+01                =   3.65E-10         \*   3.19E+05          \*     550000

  Rn~w~                       Ci_pCi_d_yr           C~Rn~                    Fp

  (Ci/yr)                     (Ci/pCi)(d/yr)        (pCi/L)                  (L/d)
  ----------------------- --- ---------------- ---- ----------------- ------ --------

<table>
<colgroup>
<col style="width: 19%" />
<col style="width: 3%" />
<col style="width: 9%" />
<col style="width: 3%" />
<col style="width: 1%" />
<col style="width: 3%" />
<col style="width: 10%" />
<col style="width: 3%" />
<col style="width: 10%" />
<col style="width: 5%" />
<col style="width: 7%" />
<col style="width: 0%" />
<col style="width: 3%" />
<col style="width: 5%" />
<col style="width: 0%" />
<col style="width: 10%" />
<col style="width: 1%" />
<col style="width: 0%" />
</colgroup>
<tbody>
<tr class="odd">
<td colspan="18"><em><strong>Rnv – – <sup>222</sup>Rn release rate from
venting (Ci/yr)</strong></em></td>
</tr>
<tr class="even">
<td colspan="18">Rnv <sub>=</sub> 3.65E-10 *
rate_of_radon_venting*C<sub>Rn</sub> * V</td>
</tr>
<tr class="odd">
<td> </td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="4"> </td>
</tr>
<tr class="even">
<td>4.89E+01</td>
<td>=</td>
<td colspan="3">3.65E-10</td>
<td>*</td>
<td colspan="3">0.01</td>
<td>*</td>
<td colspan="3">3.19E+05</td>
<td>*</td>
<td colspan="4">42000000</td>
</tr>
<tr class="odd">
<td>Rnv</td>
<td></td>
<td colspan="3">Ci_pCi_d_yr</td>
<td></td>
<td colspan="3">rate_of_radon_venting</td>
<td></td>
<td colspan="3">C<sub>Rn</sub></td>
<td></td>
<td colspan="4">V</td>
</tr>
<tr class="even">
<td>(Ci/yr)</td>
<td> </td>
<td colspan="3">(Ci/pCi)(d/yr)</td>
<td> </td>
<td colspan="3">(/d)</td>
<td> </td>
<td colspan="3">(pCi/L)</td>
<td> </td>
<td colspan="4">(m<sup>3</sup>)</td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="2"></td>
<td></td>
</tr>
<tr class="even">
<td colspan="11"><em><strong>Rnx – – <sup>222</sup>Rn release from
unloading of IX column content (Ci/yr)</strong></em></td>
<td colspan="4"></td>
<td colspan="2"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="4">Rnx <sub>=</sub> 3.65E-10 * Fi*C<sub>Rn</sub></td>
<td colspan="3"> </td>
<td> </td>
<td colspan="3"> </td>
<td colspan="4"> </td>
<td colspan="2"> </td>
<td></td>
</tr>
<tr class="even">
<td colspan="3"> </td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="2"> </td>
<td></td>
</tr>
<tr class="odd">
<td colspan="3">1.84E+00</td>
<td>=</td>
<td colspan="3">3.65E-10</td>
<td>*</td>
<td colspan="3">15840</td>
<td colspan="4">*</td>
<td colspan="2">6.40E+01</td>
<td></td>
</tr>
<tr class="even">
<td colspan="3">Rnx</td>
<td></td>
<td colspan="3">Ci_pCi_d_yr</td>
<td></td>
<td colspan="3">Fi</td>
<td colspan="4"></td>
<td colspan="2">C<sub>Rn</sub></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="3">(Ci/yr)</td>
<td> </td>
<td colspan="3">(Ci/pCi)(d/yr)</td>
<td> </td>
<td colspan="3">(L/d)</td>
<td colspan="4"> </td>
<td colspan="2">(pCi/L)</td>
<td></td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="2"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="15"><p>Total amount of <sup>222</sup>Rn released from
Production Well = Rnw + Rnv + Rnx</p>
<p> </p></td>
<td colspan="2"> </td>
<td></td>
</tr>
<tr class="even">
<td colspan="3">1.15E+02</td>
<td>=</td>
<td colspan="3">6.40E+01</td>
<td>+</td>
<td colspan="3">4.89E+01</td>
<td colspan="4">+</td>
<td colspan="2">1.84E+00</td>
<td></td>
</tr>
<tr class="odd">
<td colspan="3">Total <sup>222</sup>Rn released from production well
(Ci/yr)</td>
<td></td>
<td colspan="3">Rn<sub>w<br />
</sub>(Ci/yr)</td>
<td></td>
<td colspan="3">Rnv<br />
(Ci/yr)</td>
<td colspan="4"></td>
<td colspan="2">Rnx<br />
(Ci/yr)</td>
<td></td>
</tr>
<tr class="even">
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td></td>
<td colspan="3"></td>
<td colspan="4"></td>
<td colspan="2"></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="12"><strong>4.1.6 Land Application Area</strong></td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12"></td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12"><em><strong>Input parameters:</strong></em></td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">RCU238 – <sup>238</sup>U concentration in the holding
pond (pCi/L)</td>
<td colspan="4">1200</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">RCTh230 – <sup>230</sup>Th concentration in the holding
pond (pCi/L)</td>
<td colspan="4">5</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">RCRa226 – <sup>226</sup>Ra concentration in the holding
pond (pCi/L)</td>
<td colspan="4">30</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">RCPb210 – <sup>210</sup>Pb concentration in the holding
pond (pCi/L)</td>
<td colspan="4">30</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">U_Kd – uranium distribution coefficient
(cm<sup>3</sup>/g)</td>
<td colspan="4">50</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Th_Kd – thorium distribution coefficient
(cm<sup>3</sup>/g)</td>
<td colspan="4">60000</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">Ra_Kd – radium distribution coefficient
(cm<sup>3</sup>/g)</td>
<td colspan="4">70</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Pb_Kd – lead distribution coefficient
(cm<sup>3</sup>/g)</td>
<td colspan="4">100</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">TV – total volume of water released over operation
lifetime (m<sup>3</sup>)</td>
<td colspan="4">1.90E+06</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">TA – total area of clean wastewater land application
(m<sup>2</sup>)</td>
<td colspan="4">185000</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">Depth – depth of contaminated area (m)</td>
<td colspan="4">0.15</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Soil_density (g/cm<sup>3</sup>)</td>
<td colspan="4">1.6</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">w – Soil_volume_water_content</td>
<td colspan="4">0.25</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Radon_conc_to_radon_flux_conversion
[(pCi/m<sup>2</sup>/sec) per (pCi/g)]</td>
<td colspan="4">1</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">radionuclide_conc_to_flux_conversion
[(pCi/m<sup>2</sup>/sec) per (pCi/g)]</td>
<td colspan="4">3.10E-05</td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Rd – retardation coefficient</td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">Rd = [1 + (soil_density * distribution
coefficient)/w]</td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="16">Rs – fraction of radionuclide in irrigation water
retained in soil particles</td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">Rs = (1 – (1 / Rd))</td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Cs – radionuclide concentration in the surface soil
(pCi/g)</td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="12">RC – radionuclide concentration in the holding pond
(pCi/L)</td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
<tr class="odd">
<td colspan="12">Cs = (1E-3 * RC * TV * Rs)/(TA*depth*soil_density)</td>
<td colspan="4"></td>
<td colspan="2"></td>
</tr>
</tbody>
</table>

  ----------------- --- --- --- ---- ----- -------------- ---- ----------- --- --- ------ -----
  ***Retardation                                                                          
  coefficient                                                                             
  calculations***                                                                         

  U_Rd -                                                                                  
  retardation                                                                             
  factor for                                                                              
  uranium                                                                                 

  321               =   (   1   \+   (     1.6            \*   50          )   ∕   0.25   )

  U_Rd                                     soil_density        U_Kd                w       

                                           (g/cm^3^)           (cm^3^/g)                   
  ----------------- --- --- --- ---- ----- -------------- ---- ----------- --- --- ------ -----

  ----------------- --- --- --- ---- ----- -------------- ---- ----------- --- --- ------ -----
                                                                                          

  Th_Rd -                                                                                 
  retardation                                                                             
  factor for                                                                              
  thorium                                                                                 

  384001            =   (   1   \+   (     1.6            \*   60000       )   ∕   0.25   )

  Th_Rd                                    soil_density        Th_Kd               w       

                                           (g/cm^3^)           (cm^3^/g)                   

                                                                                          

  Ra_Rd -                                                                                 
  retardation                                                                             
  factor for radium                                                                       

  449               =   (   1   \+   (     1.6            \*   70          )   ∕   0.25   )

  Ra_Rd                                    soil_density        Ra_Kd               w       

                                           (g/cm^3^)           (cm^3^/g)                   

                                                                                          

  Pb_Rd -                                                                                 
  retardation                                                                             
  factor for lead                                                                         

  641               =   (   1   \+   (     1.6            \*   100         )   ∕   0.25   )

  Pb_Rd                                    soil_density        Pb_Kd               w       

                                           (g/cm^3^)           (cm^3^/g)                   

  ***Fractional                                                                           
  retention of                                                                            
  radionuclide in                                                                         
  surface soil                                                                            
  calculations***                                                                         

  U_Rs - uranium                                                                          
  fraction retained                                                                       
  in soil                                                                                 

  9.97E-01          =   (   1   \-   (     1              ∕    321         )   )          

  U_Rs                                                         U_Rd                       

                                                                                          

  Th_Rs - uranium                                                                         
  fraction retained                                                                       
  in soil                                                                                 

  1.00E+00          =   (   1   \-   (     1              ∕    384001      )   )          

  Th_Rs                                                        Th_Rd                      

                                                                                          

  Ra_Rs - uranium                                                                         
  fraction retained                                                                       
  in soil                                                                                 

  9.98E-01          =   (   1   \-   (     1              ∕    449         )   )          

  Ra_Rs                                                        Ra_Rd                      
  ----------------- --- --- --- ---- ----- -------------- ---- ----------- --- --- ------ -----

  ------------------- --- --- --- ---- ----- ----------- ---- -------- ---- ----
                                                                            

  Pb_Rs - uranium                                                           
  fraction retained                                                         
  in soil                                                                   

  9.98E-01            =   (   1   \-   (     1           ∕    641      )    )

  Pb_Rs                                                       Pb_Rd          
  ------------------- --- --- --- ---- ----- ----------- ---- -------- ---- ----

  ---------------------------------------------------------- --- ---------- ---- ------------------------------- -- ---- ---------- -- -- ---- ---------- -- -- ---- --------- --- ---
  ***Radon flux and radionuclide release rate                                                                                                                                      
  calculations***                                                                                                                                                                  

  Radon_flux (Ci/yr) =                                                                                                                                                             
  CsRa226\*conc_to_radon_flux_conversion\*s_yr\*TA\*Ci_pCi                                                                                                                         

  7.46E+00                                                   =   1.28E+00   \*   1.00E+00                           \*   3.15E+07         \*   1.85E+05         \*   1.0E-12        

  Radon_flux                                                     CsRn222         conc_to_radon_flux_conversion           s_yr                  TA                    Ci_pCi         

  (Ci/yr)                                                        (pCi/g)         (pCi/m^2^/sec) per (pCi/g)              sec/yr                m^2^                  Ci/pCi         

  \*assumption - ^222^Rn in equilibrium with ^226^Ra                                                                                                                                
  ---------------------------------------------------------- --- ---------- ---- ------------------------------- -- ---- ---------- -- -- ---- ---------- -- -- ---- --------- --- ---

  ---------------------------------------------------- --- ---------- ---- -------------------------- ---- ---------- -- --- ---- ---------- -- --- -------- --------- -- -- --- -- --
                                                                                                                                                                                    

  Uranium_release rate (Ci/yr) =                                                                                                                                                    
  CsU238\*conc_to_flux_conversion\*s_yr\*TA\*Ci_pCi                                                                                                                                 

  9.25E-03                                             =   5.12E+01   \*   3.10E-05                   \*   3.15E+07          \*   1.85E+05          **\***   1.0E-12                

  Uranium_release rate                                     CsU238\         conc_to_flux_conversion\        s_yr\                  TA\                        Ci_pCi                 
                                                           (pCi/g)         (pCi/m^2^/sec) per (pCi/g)      sec/yr                 m^2^                       Ci/pCi                 

  (Ci/yr)                                                                                                                                                                           

                                                                                                                                                                                    

                                                                                                                                                                                    

  Thorium_release rate (Ci/yr) =                                                                                                                                                    
  CsTh230\*conc_to_flux_conversion\*s_yr\*TA\*Ci_pCi                                                                                                                                

  3.87E-05                                             =   2.14E-01   \*   3.10E-05                   \*   3.15E+07          \*   1.85E+05          **\***   1.0E-12                

  Thorium_release rate                                     CsTh230\        conc_to_flux_conversion\        s_yr\                  TA\                        Ci_pCi                 
                                                           (pCi/g)         (pCi/m^2^/sec) per (pCi/g)      sec/yr                 m^2^                       Ci/pCi                 

  (Ci/yr)                                                                                                                                                                           

                                                                                                                                                                                    

                                                                                                                                                                                    

  Radium_release rate (Ci/yr) =                                                                                                                                                     
  CsTh230\*conc_to_flux_conversion\*s_yr\*TA\*Ci_pCi                                                                                                                                

  2.31E-04                                             =   1.28E+00   \*   3.10E-05                   \*   3.15E+07          \*   1.85E+05          \*       1.0E-12                

  Radium_release rate                                      CsRa226\        conc_to_flux_conversion\        s_yr\                  TA\                        Ci_pCi                 
                                                           (pCi/g)         (pCi/m^2^/sec) per (pCi/g)      sec/yr                 m^2^                       Ci/pCi                 

  (Ci/yr)                                                                                                                                                                           

                                                                                                                                                                                    

                                                                                                                                                                                    

  Lead_release rate (Ci/yr) =                                                                                                                                                       
  CsTh230\*conc_to_flux_conversion\*s_yr\*TA\*Ci_pCi                                                                                                                                

  2.32E-04                                             =   1.28E+00   \*   3.10E-05                   \*   3.15E+07          \*   1.85E+05          **\***   1.0E-12                

  Lead_release rate                                        CsPb210         conc_to_flux_conversion         s_yr                   TA                         Ci_pCi                 

  (Ci/yr)                                                  (pCi/g)         (pCi/m^2^/sec) per (pCi/g)      sec/yr                 m^2^                       Ci/pCi                 

                                                                                                                                                                                    
  ---------------------------------------------------- --- ---------- ---- -------------------------- ---- ---------- -- --- ---- ---------- -- --- -------- --------- -- -- --- -- --

**TABLE 4.1 Comparison of Source Release Terms for Different ISL Source
Types**

  -------------------------------- ------------------- -------------------
  Source term                      Spreadsheet         MILDOS-AREA code
                                   calculation         

  ***New Well Field***                                 

  ^222^Rn release rate, Ci/yr      2.66E-02            2.66E-02

  ***Yellow Cake Drying and                            
  Packaging***                                         

  Stack release rate -- ^238^U,    0.146               0.146
  Ci/yr                                                

  Stack release rate -- ^230^Th,   7.29E-04            7.29E-04
  Ci/yr                                                

  Stack release rate -- ^226^Ra,   7.29E-04            7.29E-04
  Ci/yr                                                

  Stack release rate -- ^210^Pb    7.29E-04            7.29E-04
  etc., Ci/yr                                          

  ***Restoration Well Field***                         

  Radon source, pCi/d              1.14E+13            1.14E+13

  ^222^Rn release rate from purge  86.5                86.5
  water into settling pond, Ci/yr                      

  ^222^Rn release rate from gas    110                 110
  venting and leaking during                           
  circulation, Ci/yr                                   

  Total ^222^Rn release rate from  197                 197
  restoration well field, Ci/yr                        

  ***Production Well Field***                          

  Radon source, pCi/d              3.42E+12            3.42E+12

  ^222^Rn release from purge       64.0                64.0
  water, Ci/yr                                         

  ^222^Rn release from venting,    48.9                48.9
  Ci/yr                                                

  ^222^Rn release from unloading   1.84                1.84
  of IX column content, Ci/yr                          

  Total ^222^Rn release, Ci/yr     115                 115

  ***Land Application Area***                          

  Radon flux, Ci/yr                7.46                7.44

  Radionuclide release rate -- U,  9.25E-03            9.22E-03
  Ci/yr                                                

  Radionuclide release rate -- Th, 3.87E-05            3.85E-05
  Ci/yr                                                

  Radionuclide release rate -- Ra, 2.31E-04            2.31E-04
  Ci/yr                                                

  Radionuclide release rate -- Pb, 2.32E-04            2.31E-04
  Ci/yr                                                
  -------------------------------- ------------------- -------------------

**4.2 Dose Comparison for Different ISL Source Types with MILDOS-Area
Source**

For this comparison, each ISL source was run separately and the sum of
allowable concentration (ALC) fractions were noted for eight residents
for a 10‑year action period. The population doses for two time periods
(10-year action period and 10‑year restoration) were also noted.

In the ISL input file, the New Well Field source is located at (-7 km,
1.2 km, 0 m) and can be simulated by a point source in MILDOS-AREA.
Table 4.2 compares the calculated sum of fraction of the ALC check for
different receptor locations for a 10-year action period and the
population doses for two time periods (10-year action period and 10-year
restoration).

In the ISL input file, the Yellow Cake Drying source is located at (0
km, 0 km, 20 m) and can be simulated by a point source in MILDOS-AREA.
Table 4.3 compares the calculated sum of fraction of the ALC check for
different receptor locations for a 10-year action period and the
population doses for two time periods (10-year action period and 10-year
restoration).

**TABLE 4.2 Dose Comparisons for New Well Field**

  ----------------------- ------------------------- ----------------------
  Comparison point        ISL source\               MILDOS-AREA\
                          (new well field)          point source

  ***Sum of ALC                                     
  fraction***                                       

  Resident 1              4.18E-07                  4.18E-07

  Resident 2              3.97E-07                  3.97E-07

  Resident 3              3.92E-07                  3.92E-07

  Resident 4              3.98E-07                  3.98E-07

  Resident 5              9.92E-07                  9.92E-07

  Resident 6              7.49E-07                  7.49E-07

  Resident 7              9.54E-07                  9.54E-07

  Resident 8              4.13E-06                  4.13E-06

  10-yr action period,    2.94E-04                  2.94E-04
  total effective dose                              
  over all population,                              
  person-rem/yr                                     

  10-yr restoration,      3.04E-07                  3.04E-07
  total effective dose                              
  over all population,                              
  person-rem/yr                                     
  ----------------------- ------------------------- ----------------------

**TABLE 4.3 Dose Comparisons for Yellow Cake Drying and Packaging
Source**

  --------------------------- ------------------- -----------------------
  Comparison point            ISL\                MILDOS-AREA\
                              (yellow cake        point source
                              drying)             

  ***Sum of ALC fraction***                       

  Resident 1                  0.0917              0.0917

  Resident 2                  0.141               0.141

  Resident 3                  0.102               0.102

  Resident 4                  0.107               0.107

  Resident 5                  0.0144              0.0144

  Resident 6                  0.0365              0.0365

  Resident 7                  0.0152              0.0152

  Resident 8                  0.00551             0.00551

  10-yr action period, total  63.42               63.42
  effective dose over all                         
  population, person-rem/yr                       

  10-yr restoration, total    0.525               0.525
  effective dose over all                         
  population, person-rem/yr                       
  --------------------------- ------------------- -----------------------

The Restoration Well Field source, when run separately in the ISL input
file, shows up as a point source located at (-0.23 km, 0.50 km, 0 m),
with a ^222^Rn release of 197 Ci/yr, and can be simulated by a point
source in MILDOS-AREA. Table 4.4 compares the calculated sum of fraction
of the ALC check for different receptor locations for the10-year action
period and the population doses for two time periods (10-year action
period and 10-year restoration).

**TABLE 4.4 Dose Comparisons for Restoration Well Field Source**

  -------------------------- ---------------------- ----------------------
  Comparison point           ISL source\            MILDOS-AREA\
                             (restoration well      point source
                             field)                 

  ***Sum of ALC fraction***                         

  Resident 1                 0.0177                 0.0177

  Resident 2                 0.0159                 0.0159

  Resident 3                 0.0116                 0.0116

  Resident 4                 0.0148                 0.0148

  Resident 5                 0.00606                0.00607

  Resident 6                 0.0116                 0.0116

  Resident 7                 0.00485                0.00486

  Resident 8                 0.0026                 0.0026

  10-yr action period, total 2.372                  2.377
  effective dose over all                           
  population, person-rem/yr                         

  10-yr restoration, total   2.286E-03              2.29E-03
  effective dose over all                           
  population, person-rem/yr                         
  -------------------------- ---------------------- ----------------------

The Production Well Field source, when run separately in the ISL input
file, shows up as a point source located at (-5.3 km, -1.3 km, 0 m),
with a ^222^Rn release of 115 Ci/yr, and can be simulated by a point
source in MILDOS-AREA. Table 4.5 compares the calculated sum of fraction
of the ALC check for different receptor locations for the 10-year action
period and the population doses for two time periods (10-year action
period and 10-year restoration).

**TABLE 4.5 Dose Comparisons for Production Well Field Source**

  --------------------------- --------------------- ---------------------
  Comparison point            ISL source\           MILDOS-AREA\
                              (production well      point source
                              field)                

  ***Sum of ALC fraction***                         

  Resident 1                  1.52E-03              1.53E-03

  Resident 2                  1.89E-03              1.89E-03

  Resident 3                  2.48E-03              2.49E-03

  Resident 4                  2.78E-03              2.79E-03

  Resident 5                  5.78E-03              5.80E-03

  Resident 6                  3.56E-03              3.57E-03

  Resident 7                  1.75E-02              1.76E-02

  Resident 8                  7.18E-03              7.20E-03

  10-yr action period, total  1.264                 1.268
  effective dose over all                           
  population, person-rem/yr                         

  10-yr restoration, total    1.321E-03             1.325E-03
  effective dose over all                           
  population, person-rem/yr                         
  --------------------------- --------------------- ---------------------

The Land Application Area source, when run separately in the ISL input
file, shows up as a point source located at (-0.78 km, -1.35 km, 0 m),
with release rates of 9.22E-04, 3.85E-05, 2.31E-04, 2.31E-04, and 7.44
Ci/yr, respectively, for ^238^U, ^230^Th, ^226^Ra, ^210^Pb, and ^222^Rn.
It can be simulated by a point source in MILDOS-AREA. Table 4.6 compares
the calculated sum of fraction of the ALC check for different receptor
locations for a 10-year action period and the population doses for two
time periods (10-year action period and 10-year restoration).

**TABLE 4.6 Dose Comparisons for Land Application Area Source**

  -------------------------- ---------------------- ---------------------
  Comparison point           ISL source\            MILDOS-AREA\
                             (land application      point source
                             area)                  

  ***Sum of ALC fraction***                         

  Resident 1                 8.41E-04               8.40E-04

  Resident 2                 7.60E-04               7.59E-04

  Resident 3                 2.80E-03               2.80E-03

  Resident 4                 2.57E-03               2.55E-03

  Resident 5                 4.29E-04               4.30E-04

  Resident 6                 9.30E-04               9.34E-04

  Resident 7                 3.45E-04               3.46E-04

  Resident 8                 1.33E-04               1.33E-04

  10-yr action period, total 0.4028                 0.4015
  effective dose over all                           
  population, person-rem/yr                         

  10-yr restoration, total   0.4245                 0.423
  effective dose over all                           
  population, person-rem/yr                         
  -------------------------- ---------------------- ---------------------

Tables 4.2 through 4.6 show that, for all practical purposes, there are
no differences in the calculated individual ALC fraction and population
doses for all ISL source types.

**5 CONCLUSIONS**

For internal checking, the limited-scope verification was done by
comparing spreadsheet calculation results with MILDOS-AREA-generated
reports. The spreadsheet calculations were performed for CHI/Q,
particulate release rates, ground deposition, air concentration, and
pathway doses. The differences between the simple spreadsheet
calculations and the MILDOS-AREA generated reports were less than 5%,
and in most cases the results were within 3%.

The MILDOS-AREA air dispersion component was compared with that of the
RESRAD-OFFSITE code. CHI/Q, particle release rate, ground deposition,
and different pathway doses were compared. It was found that there are
significant differences between the RESRAD-OFFSITE and MILDOS-AREA codes
in terms of outputs, defaults, and model components (see Section 3.9).

No significant difference was identified between the documented ISL
source derivation and its implementation within both the MILDOS-AREA
user interface and calculations. It was noted that all ISL sources
generated with the user-interface's ISL forms are represented by point
sources in the MILDOS-AREA calculations. However, users can adapt the
representation of these sources from point to area sources by applying
traditional MILDOS-AREA source types.

**6 REFERENCES**

Faillace, E.R., D.J. LePoire, S.Y. Chen, and Y. Yuan, 1997,
*MILDOS-AREA: An Update with Incorporation of In Situ Leach Uranium
Recovery Technology,* prepared by Argonne National Laboratory, Argonne,
Ill, Letter Report submitted to U.S. Nuclear Regulatory Commission, May.

Hartley, J.N., J.A. Glissmeyer, O.F. Hill, 1985, *Methods for Estimating
Radioactive and Toxic Airborne Source Terms for Uranium Milling
Operations,* NUREG/CR-4088, PNL-5338, prepared by Pacific Northwest
Laboratory, Richland, Wash., for the U.S. Nuclear Regulatory Commission,
Office of Nuclear Regulatory Research, Washington, D.C., June.

NRC: see U.S. Nuclear Regulatory Commission.

Strenge, D.L., and T.J. Bander, 1981, *MILDOS -- A Computer Program for
Calculating Environmental Radiation Doses from Uranium Recovery
Operations,* NUREG/CR-2011, PNL-3767, Pacific Northwest Laboratory,
Richland, Washington, prepared for the U.S. Nuclear Regulatory
Commission, Office of Nuclear Material Safety and Safeguards,
Washington, D.C., April.

U.S. Nuclear Regulatory Commission, 2003, *Standard Review Plan for In
Situ Leach Uranium Extraction License Applications,* Final Report,
NUREG-1569, Office of Nuclear Material Safety and Safeguards,
Washington, D.C., June.

Yu, C., E. Gnanapragasam, B.M. Biwer, S. Kamboj, J.J. Cheng, T. Klett,
D. LePoire, A.J. Zielen, S.Y. Chen, W.A. Williams, A. Wallo, S. Domotor,
T. Mo, and A. Schwartzman, 2007, *User's Manual for RESRAD-OFFSITE
Version 2*, ANL/EVS/TM-07-1, DOE/HS-0005, NUREG/CR-6937, Argonne
National Laboratory, Argonne, Ill. June.

Yuan, Y.C., J.H.C. Wang, and A. Zielen, 1989, *MILDOS-AREA: An Enhanced
Version of MILDOS for Large-Area Sources*, ANL/ES-161, Argonne National
Laboratory, Argonne, Ill. June.