ML24214A060

Enclosure 14: ENG-OCS-013 Revision: 1, Basement Fill Model: Calculation of Dcglw/F Values Assuming Industrial Use Scenario Exposure Pathways Oyster Creek Station, March 6, 2024

ML24214A060
Person / Time
Site:	Oyster Creek
Issue date:	03/06/2024
From:	Bisson J BHI Energy, Holtec Decommissioning International, Westinghouse
To:	Office of Nuclear Reactor Regulation
Shared Package
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References
HDI-OC-24-018 OCS-013, Rev 1
Download: ML24214A060 (1)

Text

ENGINEERING CALCULATION Basement Fill Model:

Calculation of DCGLW/F Values Assuming Industrial Use Scenario Exposure Pathways Oyster Creek Station ENG-OCS-013 Revision: 1 March 6, 2024 Prepared by:

BHI Energy 97 Libbey Industrial Pkwy Weymouth, MA Prepared by Approved by

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 2 1.0 PURPOSE This calculation documents the development of Basement Fill Model (BFM) derived concentration guideline levels values for the walls and floors (DCGLw/f) applying the exposure pathways assumed for the Industrial Use (IU) scenario to support the assessment of below-grade concrete structures.

2.0 APPLICABILITY This calculation addresses only the development of BFM DCGLw/f values for the Oyster Creek site.

3.0 REFERENCES

3.1 BHI Energy Engineering Procedure ENG-AP-02, Verification of Software Operability 3.2 ANL/EAD-4, Users Manual for RESRAD Version 6, U.S. Department of Energy - Argonne National Laboratory, July 2001 3.3 ANL/EVS/TM-18/1, RESRAD-Onsite 7.2 Users Guide, April 2018 3.4 Radionuclide Selection for DCGL Development-Oyster Creek Station Site Characterization Project, January 2022 3.5 ENG-OCS-012, Basement Fill Model Probabilistic Analysis: IU Instantaneous Release Scenario, November 2023 3.6 ENG-OCS-008, Derived Concentration Guideline Levels Values for Soil - Industrial Use Scenario, July 2023 3.7 Holtec-00045 Calc-001, Oyster Creek Generating Station Assessment of Subsurface Structures 3.8 ENG-OCS-009, Area Factors for Soil - Industrial Use Scenario, August 2022 4.0 DISCUSSION The operability of the RESRAD-Onsite 7.2 computer code was verified on each computer used for code executions in accordance with BHI Energy Engineering procedure ENG-AP-02, Verification of Software Operability [3.1]. The RESRAD code has undergone extensive review, benchmarking, verification, and validation [3.2]. The RESRAD-Onsite 7.2 Users Guide [3.3] was used as a reference for code use.

The BFM DCGLw/f values based on IU assumptions incorporate 3 scenarios: (1) an instantaneous release scenario, (2) drilling spoils scenario, and a concrete excavation scenario. Detailed descriptions, assumptions, and calculations for each scenario are provided in sections 6, 7, and 8, respectively. Calculations of BFM DCGLw/f values for the IU scenario are found in section 9.

The Industrial Use Scenario: The average member of the critical group is a hypothetical full-time industrial site worker assigned outdoor tasks and who also catches and consumes fish from the intake/discharge canal during off-hours. The pathways used to estimate human radiation exposure resulting from residual radioactivity in the soil for this scenario are:

Direct external radiation exposure pathway Inhalation exposure pathway Ingestion exposure via aquatic food from the intake/discharge canal Inadvertent ingestion of contaminated soil

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 3 5.0 RADIONUCLIDES OF CONCERN 5.1 Radionuclides-of-concern (ROCs): A site-specific suite of potential ROCs has been identified for the OCS site [3.4]. OCS ROCs are listed in Table 5-1.

NOTE: RESRAD-Onsite 7.2 automatically accounts for progeny radionuclides with input for several of the OCS ROCs. Progeny radionuclides are also listed in Table 5-1.

Table 5-1: Potential Radionuclides-of-Concern Identified for the OCS Site ROCa Progenyb ROCa Progenyb Am-241 Np-237, Th-229, U-233 Nb-94 C-14 Ni-63 Cm-243 Ac-227, Am-243, Pa-231, Pu-239, U-235 Np-237 Th-229, U-233 Cm-244 Pu-240, Ra-228, Th-228, Th-232, U-236 Pu-238 Pb-210, Po-210, Ra-226, Th-230, U-234 Cs-137 Pu-239 Ac-227, Pa-231, U-235 Co-60 Pu-240 Ra-228, Th-228, Th-232, U-236 Eu-152 Gd-152 Pu-241 Am-241, Np-237, Th-229, U-233 Eu-154 Sb-125 Te-125m Fe-55 Sr-90 H-3 Tc-99 Mn-54 a ROC = radionuclide-of-concern identified for the OCS site.

b Included automatically with input of parent ROC.

6.0 Instantaneous Release Scenario 6.1 Scenario Description The Instantaneous Release (IR) scenario assumes an instantaneous release of radioactive contamination from sub-surface concrete surfaces to fill material immediately adjacent within 1m distance from the concrete surfaces, thereby creating the scenarios contaminated volume (CV). The CV is assumed to be uniformly mixed, covered by 3ft (0.91m) of site soil, and extends to a depth of 43ft (13.1m), which is the depth of the Reactor Building foundation walls. Site-specific modeling places portions of the CV in 2 soil strata: the unsaturated zone (UZ) and the saturated zone (SZ). The UZ is the stratum above the average depth of site groundwater whereas the SZ begins at the groundwater table depth. The below-grade concrete structures are assumed not to impede groundwater flow. The conceptual configuration of the contaminated zone (CZ) created by the CV is shown in Figure 6-1. The CV is assessed using the exposure assumptions and pathways of the IU scenario.

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 4 Figure 6-1. Conceptual Representation of CV for the Instantaneous Release Scenario 6.2 Calculation Method The IR scenario incorporates the results from probabilistic analyses of RESRAD-Onsite parameters in ENG-OCS-012 [3.5]. The 75th percentile and 25th percentile values of the distributions used as input for RESRAD-Onsite parameters identified as sensitive in ENG-OCS-012 are recommended as reasonably conservative input values for calculations of DCGL values. The approach of assigning 25th and 75th percentile values of a sensitive parameters distribution to account for uncertainty has been found acceptable by the U.S. Nuclear Regulatory Commission (NRC) and State regulators as a reasonably conservative approach for capturing the uncertainty associated with the sensitive parameters. Refer to ENG-OCS-012 for details regarding the probabilistic analyses.

RESRAD-Onsite code executions were performed for each ROC identified for the OCS site. The probabilistic module of RESRAD-Onsite software was used to compute a peak of the mean (POM) dose, which was used to determine the DCGL values corresponding to the NRC dose criteria established in 10CFR20.1403 (i.e., 25 mrem/y).

In addition to the RESRAD-Onsite results, calculations of the ROC-specific DCGL values relied on 2 other calculations.

3ft (0.91m)

UZ: 11.5ft (3.5m) 26.74% in UZ SZ: 31.5ft (9.6m)

<------------- well intake depth ----------->

73.26% in SZ

= CV

<------CZ thickness = RB wall height 43 ft (13.11m) -------->

GW flow----->

<---- CZ width 145.3 ft (44.3m = LPAF)-- >

well site grade cover GW table @14.5ft (4.42m) 1-~1 I

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 5 The first is the calculation of the activity concentrations in fill material (pCi/g) that corresponded to surface activity concentrations equal to 1 pCi/m2. This was accomplished using the following equation:

Cfill = As/(V)(1E6)(D)

Eq. 6-1 Where:

Cfill = activity concentration in the fill material (pCi/g) per surface area activity concentration = 1 pCi/m2 As = unit surface area activity concentration assumed over 1 m2 of concrete surface (1 pCi)

Vfill = unit volume of fill material (1 m3) 1E6 = conversion factor (cm3 per m3)

Dfill = density of fill material (g/cm3)

Calculation of ROC-specific DCGLIR values using RESRAD-Onsite POM doses, 10CFR20.1402 dose criterion, and activity concentration calculated using equation 6-1. This was accomplished using equation 6-2 below.

DCGLIR,ROC = [25 ÷ (POMROC x Cfill)]

Eq. 6-2 Where:

DCGLIR,ROC = ROC-specific DCGLIR value (pCi/m2) 25 = 10CFR20.1402 unrestricted release criterion (mrem/y)

POMROC = ROC-specific POM dose (mrem/y per 1 pCi/g) calculated using RESRAD-Onsite 7.2 Cfill = activity concentration in the fill material (pCi/g) per pCi/m2 determined using equation 1 6.3 Input for Instantaneous Release (IR) DCGL Calculations 6.3.1 Modeling of the IR scenario is described in detail in ENG-OCS-010. The values for the RESRAD-Onsite input parameters that define the CV were taken from ENG-OCS-010 and presented below.

Instantaneous release CV: 20,184 m3.

CZ area: 1539.6 m2.

Diameter of the CV = length parallel to aquifer flow parameter: 44.3m.

Fractions of CV in the SZ: 0.7326 UZ thickness: 3.5m 6.3.2 All other input for RESRAD-Onsite parameters (e.g., soil type, kd values, hydrogeologic input, occupancy, dietary, etc.) are the same as those used in the probabilistic analyses (ENG-OCS-012).

The value and basis for each RESRAD-Onsite parameter are provided in Table 6-1.

6.4 Calculation Results 6.5 The calculated POM dose for each ROC is provided in column 2 of Table 6-2. Pages from the RESRAD-Onsite 7.2 output reports showing the calculated POM doses by ROC are provided in Appendix A.

6.6 For all ROCs, the activity concentration in fill material (in units of pCi/g) that corresponded to a surface area activity concentration equal to 1 pCi/m2 using equation 6-1:

Cfill = AS /(Vfill x 1E6 x Dfill)

The mean value (1.5105 g/cm3) of the density distribution for sand was applied for all ROCs because none was identified as sensitive for the density of CZ soil (refer to ENG-OCS-012).

Cfill = 1pCi/(1m3

• 1E+06 cm3/m3

• 1.5101g/cm3) = 6.62E-07 pCi/g per 1 pCi/m2 6.7 Column 3 of Table 6-2 provides ROC-specific DCGLIR values derived using equation 6-2. Input for equation 6-2 were the RESRAD-Onsite 7.2 POM doses (mrem/y per pCi/g), 10CFR20.1402

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 6 dose criterion (25 mrem/y), and the values of Cfill calculated in step 6.6 (6.62E-07 pCi/g per 1 pCi/m2 for all ROCs).

DCGLIR,ROC = [25 ÷ (POMROC x Cfill)]

An Excel spreadsheet was used for calculations of the DCGLIR,ROC values. The following hand calculations for Am-241 and H-3 confirmed the operability of the spreadsheet.

DCGLIR for Am-241 = 25 mrem/y ÷ (2.56E-04 mrem/y per pCi/g

• 6.62E-07 pCi/g per 1 pCi/m2)

= 1.48E+11 pCi/m2. (Note: Difference at the last digit is due to rounding of decimal places retained in Excel spreadsheet.)

DCGLIR for H-3 = 25 mrem/y ÷ (1.17E-08 mrem/y per pCi/g

• 6.62E-07 pCi/g per 1 pCi/m2) =

3.23E+15 pCi/m2. (Note: Difference at the last digit is due to rounding of decimal places retained in Excel spreadsheet.)

Table 6-1. Summary of Values for RESRAD Input Parameters Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario RESRAD Exposure Pathways External Gamma Open Inhalation Open Plant Ingestion Close Meat Ingestion Close Milk Ingestion Close Aquatic Foods Open Drinking Water Close Soil Ingestion Open Radon Close Parameter (unit)

Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd Median/

Mean 1

2 3

4 Soil Concentrations Basic radiation dose limit (mrem/y)

P 3

D 25 10 CFR 20.1402 NR NR NR NR Initial principal radionuclide (pCi/g)

P 2

D 1

Unit Value NR NR NR NR Distribution coefficients (sand soil type assigned to contaminated, unsaturated. and saturated zones) (cm3/g)

Ac-227 P

1 S

Truncated lognormal-n NUREG/CR-7267 7.44 1.1 0.001 0.999 1700 Am-241 P

1 D

D S

3.71E+03 (CZ) 2.69E+02 (UZ)

Truncated lognormal-n 75th percentile value 25th percentile value ANL/EVS/TM-14/4 6.91 1.95 0.001 0.999 1000 Am-243 P

1 D

S 3.71E+03 (CZ)

Truncated lognormal-n 75th percentile value ANL/EVS/TM-14/4 6.91 1.95 0.001 0.999 1000 C-14 P

1 D

D S

7.11E+01 (CZ) 6.14E+00 (UZ)

Truncated lognormal-n 75th percentile value 25th percentile value ANL/EVS/TM-14/4 3.04 1.82 0.001 0.999 21 Cm-243 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 8.13 2.64 0.001 0.999 3400 Cm-244 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 8.13 2.64 0.001 0.999 3400

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 7 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Co-60 P

1 D

S 3.71E+01 (CZ)

Truncated lognormal-n 25th percentile value ANL/EVS/TM-14/4 5.56 2.89 0.001 0.999 260 Cs-137 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 6.27 1.79 0.001 0.999 530 Eu-152 P

1 D

S 1.41E+04 (CZ)

Truncated lognormal-n 75th percentile value ANL/EVS/TM-14/4 6.86 4.01 0.001 0.999 955 Eu-154 P

1 D

S 1.41E+04 (CZ)

Truncated lognormal-n 75th percentile value ANL/EVS/TM-14/4 6.86 4.01 0.001 0.999 955 Fe-55 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 5.77 0

0.001 0.999 320 Gd-152 P

1 S

Truncated lognormal-n NUREG/CR-7267 1.61 3.22 0.001 0.999 5

H-3 P

1 S

Truncated lognormal-n NUREG/CR-7267

-2.81 0.5 0.001 0.999 0.06 Mn-54 P

1 D

S 5.78E+03 (CZ)

Truncated lognormal-n 75th percentile value ANL/EVS/TM-14/4 6.89 2.64 0.001 0.999 980 Nb-94 P

1 D

S 3.80E+03 (CZ)

Truncated lognormal-n 75th percentile value ANL/EVS/TM-14/4 7.31 1.39 0.001 0.999 1500 Ni-63 P

1 D

S 2.77E+01 (UZ)

Truncated lognormal-n 25th percentile value ANL/EVS/TM-14/4 4.87 2.3 0.001 0.999 130 Np-237 P

1 D

D S

3.56E+01 (CZ) 5.49+00 (UZ)

Truncated lognormal-n 75th percentile value 25th percentile value ANL/EVS/TM-14/4 2.64 1.39 0.001 0.999 14 Pa-231 P

1 S

Truncated lognormal-n NUREG/CR-7267 7.6 1.1 0.001 0.999 2000 Pb-210 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 5.39 1.39 0.001 0.999 220 Po-210 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 4.61 1.79 0.001 0.999 100 Pu-238 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 5.99 1.39 0.001 0.999 400 Pu-239 P

1 D

D S

1.02E+03 (CZ) 1.57E+02 (UZ)

Truncated lognormal-n 75th percentile value 25th percentile value ANL/EVS/TM-14/4 5.99 1.39 0.001 0.999 400 Pu-240 P

1 D

D S

1.02E+03 (CZ) 1.57E+02 (UZ)

Truncated lognormal-n 75th percentile value 25th percentile value ANL/EVS/TM-14/4 5.99 1.39 0.001 0.999 400 Pu-241 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 5.99 1.39 0.001 0.999 400 Ra-226 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 8.04 2.08 0.001 0.999 3100 Ra-228 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 8.04 2.08 0.001 0.999 3100

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 8 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Sb-125 P

1 D

S 5.64E+01 (CZ)

Truncated lognormal-n 75th percentile value ANL/EVS/TM-14/4 2.83 1.79 0.001 0.999 17 Sr-90 P

1 D

S 6.58E+00 (CZ & UZ)

Truncated lognormal-n 25th percentile value ANL/EVS/TM-14/4 3.09 1.79 0.001 0.999 22 Tc-99 P

1 D

S 1.90E-02 (UZ)

Truncated lognormal-n 25th percentile value ANL/EVS/TM-14/4

-3.22 1.1 0.001 0.999 0.04 Te-125m P

1 S

Truncated lognormal-n NUREG/CR-7267 6.31 3.22 0.001 0.999 550 Th-228 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 6.55 2.4 0.001 0.999 700 Th-229 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 6.55 2.4 0.001 0.999 700 Th-230 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 6.55 2.4 0.001 0.999 700 Th-232 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 6.55 2.4 0.001 0.999 700 U-233 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 4.7 2.48 0.001 0.999 110 U-234 P

1 D

S 2.07E+01 (CZ & UZ)

Truncated lognormal-n 25th percentile value ANL/EVS/TM-14/4 4.7 2.48 0.001 0.999 110 U-235 P

1 S

Truncated lognormal-n ANL/EVS/TM-14/4 4.7 2.48 0.001 0.999 110 U-236 P

1 D

S 2.07E+01 (UZ)

Truncated lognormal-n 25th percentile value ANL/EVS/TM-14/4 4.7 2.48 0.001 0.999 110 Initial concentration of radionuclides present in groundwater (pCi/l)

P 3

D 0

Ground water uncontaminated NR NR NR NR Calculation Times Time since placement of material (y)

P 3

D 0

NR NR NR NR Time for calculations (y)

P 3

D 0, 1, 3, 10, 30, 100, 300, 1000 RESRAD Default NR NR NR NR Contaminated Zone Area of contaminated zone (m2)

P 2

D 1539.6 Based on contaminated volume and height of RB wall.

NR NR NR NR Thickness of contaminated zone (m)

P 2

D 13.1 CZ thickness set to RB wall height.

NR NR NR NR Length parallel to aquifer flow (m)

P 2

D 44.3 Set to diameter of CZ.

NR NR NR NR Does the initial contamination penetrate the water table?

Yes Based on site features and RB dimensions.

Contaminated fraction below water table D

.7326 Based on OCGS site data; average groundwater depths recorded for wells around the RB, TB, and ORB.

NR NR NR NR Cover and Contaminated Zone Hydrological Data Cover depth (m)

P 2

D 0.91 3ft cover assumed.

NR NR NR NR

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 9 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Cover density (g/cm3)

P 2

D S

1.40E+00 (C-14, Co-60, Cs-137, Eu-152, Eu-154, Mn-54, Nb-94, Np-237, Pu-238, Pu-240, Sb-125, Sr-90)

Truncated Normal (all ROCs not listed above) 25th percentile value Site soil type = sand (2017 Hydrogeologic Investigation Report).

Input for density of fill material = NUREG/CR-7267 density distribution for site soil type - sand.

1.5105 0.159 0.001 0.999 1.5105 Cover erosion rate (m/y)

P 2

D 6E-04 Assumed final site grade is level. Input for erosion rate = NUREG/CR-7267 erosion rate for site with shallow slope (i.e.,

relatively level)

NR NR NR NR Density of contaminated zone (g/cm3)

P 1

S Truncated Normal Site soil type = sand (2017 Hydrogeologic Investigation Report).

Input for density of fill material = NUREG/CR-7267 density distribution for site soil type - sand.

1.5105 0.159 0.001 0.999 1.5105 Contaminated zone erosion rate (m/y)

P 2

D 6E-04 Assumed same as cover.

NR NR NR NR Contaminated zone total porosity P

2 S

Bounded Normal NUREG/CR-7267 distribution for site soil type -sand 0.43 0.06 0.2446 0.6154 0.43 Contaminated zone field capacity P

3 D

0.18 Value based on site-specific soil type (sand);

calculated using equation in NUREG/CR-7267 NR NR NR NR Contaminated zone hydraulic conductivity (m/y)

P 2

D 2741 2017 Hydrogeologic Investigation Report NR NR NR NR Contaminated zone b parameter P

2 S

Bounded Log Normal n NUREG/CR-7267 distribution for site soil type - sand

- 0.0253 0.216 0.501 1.90 0.975 Humidity in air (g/m3)

P 3

D 6.6 From Regional and Site-Specific Absolute Humidity Data for Use in Tritium Dose Calculations.

NR NR NR NR Evapotranspiration coefficient P

2 D

S 5.62E-01 (Tc-99)

Uniform (all other ROCs) 25th percentile value NUREG/CR-7267 distribution 0.5 0.75 0.625 Average annual wind speed (m/s)

P 2

D 3.13 Internet search:

https://www.windfinder.co m/windstatistics/oyster_cre ek_barnegat_bay NR NR NR NR Precipitation (m/y)

P 2

D 1.4 Annual Report on the Meteological Program at Oyster Creek Generating Station - average annual precipitation for 2015 through 2020 NR NR NR NR

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 10 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Irrigation (m/y)

B 3

S Uniform Distribution determined using methodology described in Data Collection Handbook and NUREG/CR-6697 0

0.08 0.04 Irrigation mode B

3 D

Overhead Overhead irrigation is common practice for crops in U.S.

NR NR NR NR Runoff coefficient P

2 D

0.2 Value determined using methodology described in Data Collection Handbook and NUREG/CR-7267 NR NR NR NR Watershed area for nearby stream or pond (m2)

P 3

D 1.01E+08 NJ-GeoWeb (NJDEP BGIS)

NR NR NR NR Accuracy for water/soil computations 3

D 1.00E-03 RESRAD Default NR NR NR NR Saturated Zone Hydrological Data Density of saturated zone (g/cm3)

P 1

S Truncated Normal NUREG/CR-7267 distribution for site soil type -sand 1.5105 0.159 0.001 0.999 1.5105 Saturated zone total porosity P

1 S

Truncated Normal NUREG/CR-7267 distribution for site soil type -sand 0.43 0.06 0.001 0.999 0.43 Saturated zone effective porosity P

1 D

0.25 2017 Hydrogeologic Investigation Report NR NR NR NR Saturated zone field capacity P

3 D

0.18 Value based on site-specific soil type (sand);

calculated using equation in NUREG/CR-7267 NR NR NR NR Saturated zone hydraulic conductivity (m/y)

P 1

D 2741 2017 Hydrogeologic Investigation Report NR NR NR NR Saturated zone hydraulic gradient P

2 D

S 1.75E-02 (H-3 & Nb-94)

Uniform 25th percentile value 2017 Hydrogeologic Investigation Report 0.01 0.04 0.025 Saturated zone b parameter P

2 S

N/A Input not required when CZ is in SZ NR NR NR NR Water table drop rate (m/y)

P 3

D 0

CZ in SZ NR NR NR NR Well pump intake depth (m below water table)

P 2

D 9.6 Set to the distance from the water table to the lower boundary of contamination in the aquifer at the downgradient edge of the contaminated zone.

NR NR NR NR Model:

Nondispersion (ND) or Mass-Balance (MB)

P 3

D ND ND model recommended for contaminant areas

>1,000 m2 NR NR NR NR Well pumping rate (m3/y)

P 2

S N/A Input not required.

NR NR NR NR Unsaturated Zone Hydrological Data Unsaturated zones P

3 D

1 NR NR NR NR Unsat. zone 1, thickness (m)

P 1

D 3.5 11.5 ft (3.5m) of CZ located between cover and groundwater table.

NR NR NR NR Unsat. zone 1, soil density (g/cm3)

P 2

S Truncated Normal NUREG/CR-7267 distribution for site soil type - sand 1.5105 0.159 0.001 0.999 1.5105

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 11 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Unsat. zone 1, total porosity P

2 S

Truncated Normal NUREG/CR-7267 distribution for site soil type - sand 0.43 0.06 0.001 0.999 0.43 Unsat. zone 1, effective porosity P

2 D

0.25 2017 Hydrogeologic Investigation Report NR NR NR NR Unsat. zone 1, field capacity P

3 D

0.18 Value based on site-specific soil type (sand);

calculated using equation in NUREG/CR-7267 NR NR NR NR Unsat. zone 1, hydraulic conductivity (m/y)

P 2

D 2741 2017 Hydrogeologic Investigation Report NR NR NR NR Unsat. zone 1, soil-specific b parameter P

2 S

Bounded Log Normal n NUREG/CR-7267 distribution for site soil type - sand

- 0.0253 0.216 0.501 1.90 0.975 Occupancy Inhalation rate (m3/y)

B 3

D 8400 NUREG/CR-7267 NR NR NR NR Mass loading for inhalation (g/m3)

P 2

S Continuous linear NUREG/CR-7267 2.3E-5 Exposure duration B

3 D

30 RESRAD Default NR NR NR NR Indoor dust filtration factor P

2 S

Uniform NUREG/CR-7267 0.15 0.95 0.55 Shielding factor, external gamma P

2 D

S 4.00E-01 (Co-60, Cs-137,

& Mn-54)

Bounded lognormal-n (all other ROCs) 75th percentile value NUREG/CR-7267

-1.3 0.59 0.044 1

0.2725 Fraction of time spent indoors B

3 D

0.03 Fraction of calendar year assuming 1h/work day for daily work breaks NR NR NR NR Fraction of time spent outdoors B

3 D

0.2 Fraction of calendar year assuming 7h/work day for outside tasks NR NR NR NR Shape factor flag, external gamma P

3 D

Circular Circular contaminated zone assumed NR NR NR NR Ingestion, Dietary Fruits, vegetables, grain consumption (kg/y)

B 2

D N/A Input not required - plant ingestion pathway inactive NR NR NR NR Leafy vegetable consumption (kg/y)

B 3

D N/A Input not required - plant ingestion pathway inactive NR NR NR NR Milk consumption (L/y)

B 2

D N/A Input not required - milk ingestion pathway inactive NR NR NR NR Meat and poultry consumption (kg/y)

B 3

D N/A Input not required - meat ingestion pathway inactive NR NR NR NR Fish consumption (kg/y)

B 3

D 20.6 NUREG/CR-5512, Vol. 3 NR NR NR NR Other seafood consumption (kg/y)

B 3

D 0.9 RESRAD Default NR NR NR NR Soil ingestion rate (g/yr)

B 2

D Triangular NUREG/CR-7267 0

18.3 36.5 18.3 Drinking water intake (L/y)

B 2

D N/A Input not required -

drinking water pathway inactive NR NR NR NR Contamination fraction of drinking water P

3 D

N/A Input not required -

drinking water pathway inactive NR NR NR NR Contamination fraction of household water P

3 N/A Input not required - water pathway inactive

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 12 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Contamination fraction of livestock water P

3 D

N/A Input not required -

drinking water/ingestion pathways inactive NR NR NR NR Contamination fraction of irrigation water P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Contamination fraction of aquatic food P

2 D

S 6.10E-01 (H-3 & Tc-99)

Triangular (all other ROCs) 75th percentile value NUREG/CR-7267 0

0.39 1.0 0.39 Contamination fraction of plant food P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Contamination fraction of meat P

3 D

N/A Input not required - meat ingestion pathway inactive NR NR NR NR Contamination fraction of milk P

3 D

N/A Input not required - milk ingestion pathway inactive NR NR NR NR Ingestion, Non-Dietary Livestock fodder intake for meat (kg/d)

M 3

D N/A Input not required - meat ingestion pathway inactive NR NR NR NR Livestock fodder intake for milk (kg/d)

M 3

D N/A Input not required - milk ingestion pathway inactive NR NR NR NR Livestock water intake for meat (L/d)

M 3

D N/A Input not required - water ingestion pathway inactive NR NR NR NR Livestock water intake for milk (L/d)

M 3

D N/A Input not required - milk ingestion pathway inactive NR NR NR NR Livestock soil intake (kg/d)

M 3

D N/A Input not required - meat ingestion pathway inactive NR NR NR NR Mass loading for foliar deposition (g/m3)

P 3

D N/A Input not required - plant ingestion pathway inactive NR NR NR NR Depth of soil mixing layer (m)

P 2

D S

3.40E-01 (Am-241, Cm-243, Cm-244, Pu-239, &

Pu-241)

Triangular (all other ROCs) 75th percentile value NUREG/CR-7267 0

0.15 0.6 0.23 Depth of roots (m)

P 1

S N/A Input not required - plant ingestion pathway inactive 0.3 4

1.85 Drinking water fraction from ground water P

3 D

N/A Input not required -

drinking water ingestion pathway inactive NR NR NR NR Household water fraction from ground water P

3 N/A Input not required -

drinking water pathway inactive Livestock water fraction from ground water P

3 D

N/A Input not required -

drinking water/meat ingestion pathways inactive NR NR NR NR Irrigation fraction from ground water P

3 D

N/A Input not required -

drinking water pathway inactive NR NR NR NR Wet weight crop yield for Non-Leafy (kg/m2)

P 2

S N/A Input not required - plant ingestion pathway inactive 0.56 0.48 0.001 0.999 1.75 Wet weight crop yield for Leafy (kg/m2)

P 3

D N/A Input not required - plant ingestion pathway inactive NR NR NR NR Wet weight crop yield for Fodder (kg/m2)

P 3

D N/A Input not required - meat ingestion pathway inactive NR NR NR NR Growing Season for Non-Leafy (y)

P 3

D N/A Input not required - plant ingestion pathway inactive NR NR NR NR

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 13 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Growing Season for Leafy (y)

P 3

D N/A Input not required - plant ingestion pathway inactive NR NR NR NR Growing Season for Fodder (y)

P 3

D N/A Input not required - meat ingestion pathway inactive NR NR NR NR Translocation Factor for Non-Leafy P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Translocation Factor for Leafy P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Translocation Factor for Fodder P

3 D

N/A Input not required - meat ingestion pathway inactive NR NR NR NR Weathering Removal Constant for Vegetation (1/y)

P 2

S N/A Input not required - plant ingestion pathway inactive 5.1 18 84 33 Wet Foliar Interception Fraction for Non-Leafy P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Wet Foliar Interception Fraction for Leafy P

2 S

N/A Input not required - plant ingestion pathway inactive 0.06 0.67 0.95 0.58 Wet Foliar Interception Fraction for Fodder P

3 D

N/A Input not required - meat ingestion pathway inactive NR NR NR NR Dry Foliar Interception Fraction for Non-Leafy P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Dry Foliar Interception Fraction for Leafy P

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Dry Foliar Interception Fraction for Fodder P

3 D

N/A Input not required - meat ingestion pathway inactive NR NR NR NR Storage times of contaminated foodstuffs (days):

Fruits, non-leafy vegetables, and grain B

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Leafy vegetables B

3 D

N/A Input not required - plant ingestion pathway inactive NR NR NR NR Milk B

3 D

N/A Input not required - milk ingestion pathway inactive NR NR NR NR Meat and poultry B

3 D

N/A Input not required - meat ingestion pathway inactive NR NR NR NR Fish B

3 D

7 RESRAD Default NR NR NR NR Crustacea and mollusks B

3 D

7 RESRAD Default NR NR NR NR Well water B

3 D

N/A Input not required -

drinking water pathway inactive NR NR NR NR Surface water B

3 D

N/A Input not required drinking water pathway inactive NR NR NR NR Livestock fodder B

3 D

N/A Input not required - meat ingestion pathway inactive NR NR NR NR Special Radionuclides (C-14)

C-12 concentration in water (g/cm3)

P 3

D 2.00E-05 RESRAD Default NR NR NR NR C-12 concentration in contaminated soil (g/g)

P 3

D 3.00E-02 RESRAD Default NR NR NR NR Fraction of vegetation carbon from soil P

3 D

2.00E-02 RESRAD Default NR NR NR NR

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 14 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Fraction of vegetation carbon from air P

3 D

9.80E-01 RESRAD Default NR NR NR NR C-14 evasion layer thickness in soil (m)

P 2

S Triangular NUREG/CR-7267 0.2 0.3 0.6 0.3 C-14 evasion flux rate from soil (1/s)

P 3

D 7.00E-07 RESRAD Default NR NR NR NR C-12 evasion flux rate from soil (1/s)

P 3

D 1.00E-10 RESRAD Default NR NR NR NR Fraction of grain in beef cattle feed B

3 D

0.2500 NUREG/CR-7267 NR NR NR NR Fraction of grain in milk cow feed B

3 D

0.1000 NUREG/CR-7267 NR NR NR NR Inhalation Dose Conversion Factors (mrem/pCi inhaled) from FGR11 (contained in RESRAD Dose Conversion Library)

Ingestion Dose Conversion Factors (mrem/pCi ingested) from FGR11 (contained in RESRAD Dose Conversion Library)

Plant Transfer Factors (pCi/g plant)/(pCi/g soil)

Note: Plant ingestion pathway closed - input for plant transfer factors not required for Industrial Use dose calculations.

Meat Transfer Factors (pCi/kg)/(pCi/d)

Note: Meat ingestion pathway closed - input for meat transfer factors not required for Industrial Use dose calculations.

Milk Transfer Factors (pCi/L)/(pCi/d)

Note: Milk ingestion pathway closed - input for milk transfer factors not required for Industrial Use dose calculations.

Bioaccumulation (Transfer) Factors for Fish ((pCi/kg)/(pCi/L))

Ac-227 P

2 S

Lognormal-n NUREG/CR-7267 3.2 1.1 2.5E+01 Am-241 P

2 S

Lognormal-n NUREG/CR-7267 5.5 1.1 2.4E+02 Am-243 P

2 S

Lognormal-n NUREG/CR-7267 5.5 1.1 2.4E+02 C-14 P

2 S

Lognormal-n NUREG/CR-7267 13.0 1.1 4.4E+05 Cm-243 P

2 S

Lognormal-n NUREG/CR-7267 3.4 1.1 3.0E+01 Cm-244 P

2 S

Lognormal-n NUREG/CR-7267 3.4 1.1 3.0E+01 Co-60 P

2 S

Lognormal-n NUREG/CR-7267 4.3 0.9 7.4E+01 Cs-137 P

2 S

Lognormal-n NUREG/CR-7267 7.8 0.9 2.4E+03 Eu-152 P

2 S

Lognormal-n NUREG/CR-7267 4.9 1.6 1.3E+02 Eu-154 P

2 S

Lognormal-n NUREG/CR-7267 4.9 1.6 1.3E+02 Fe-55 P

2 S

Lognormal-n NUREG/CR-7267 5.1 1.9 1.6E+02 Gd-152 P

2 S

Lognormal-n NUREG/CR-7267 3.4 1.1 3.0E+01 H-3 P

2 S

Lognormal-n NUREG/CR-7267 0

0.1 1.0E+00 Mn-54 P

2 S

Lognormal-n NUREG/CR-7267 5.5 1.9 2.4E+02 Nb-94 P

2 S

Lognormal-n NUREG/CR-7267 5.7 1.1 3.0E+02 Ni-63 P

2 S

Lognormal-n NUREG/CR-7267 3.0 0.6 2.0E+01 Np-237 P

2 S

Lognormal-n NUREG/CR-7267 3.0 1.1 2.0E+01 Pa-231 P

2 S

Lognormal-n NUREG/CR-7267 2.3 1.1 1.0E+01 Pb-210 P

2 S

Lognormal-n NUREG/CR-7267 3.2 1.1 2.5E+02 Po-210 P

2 S

Lognormal-n NUREG/CR-7267 3.6 1.5 3.7E+01 Pu-238 P

2 S

Lognormal-n NUREG/CR-7267 10.0 1.0 2.2E+04 Pu-239 P

2 S

Lognormal-n NUREG/CR-7267 10.0 1.0 2.2E+04 Pu-240 P

2 S

Lognormal-n NUREG/CR-7267 10.0 1.0 2.2E+04 Pu-241 P

2 S

Lognormal-n NUREG/CR-7267 10.0 1.0 2.2E+04 Ra-226 P

2 S

Lognormal-n NUREG/CR-7267 1.4 1.9 4.1E+00 Ra-228 P

2 S

Lognormal-n NUREG/CR-7267 1.4 1.9 4.1E+00 Sb-125 P

2 S

Lognormal-n NUREG/CR-7267 3.6 1.5 3.7E+01 Sr-90 P

2 S

Lognormal-n NUREG/CR-7267 1.1 1.4 3.0E+00

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 15 Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Tc-99 P

2 D

4.21E+01 75th percentile value Te-12m P

2 S

Lognormal-n NUREG/CR-7267 5.0 0.4 1.5E+02 Th-228 P

2 S

Lognormal-n NUREG/CR-7267 4.6 1.1 9.9E+01 Th-229 P

2 S

Lognormal-n NUREG/CR-7267 4.6 1.1 9.9E+01 Th-230 P

2 S

Lognormal-n NUREG/CR-7267 4.6 1.1 9.9E+01 U-233 P

2 S

Lognormal-n NUREG/CR-7267 0.0 2.5 1.0E+00 U-234 P

2 S

Lognormal-n NUREG/CR-7267 0.0 2.5 1.0E+00 U-235 P

2 S

Lognormal-n NUREG/CR-7267 0.0 2.5 1.0E+00 U-236 P

2 S

Lognormal-n NUREG/CR-7267 0.0 2.5 1.0E+00 Bioaccumulation Factors for Crustacea/ Mollusks ((pCi/kg)/(pCi/L)) RESRAD default value for each radionuclide applied Graphics Parameters Number of points 32 RESRAD Default NR NR NR NR Spacing log RESRAD Default NR NR NR NR Time integration parameters Maximum number of points for dose 17 RESRAD Default NR NR NR NR Table 6-1 Notes:

a P = physical, B = behavioral, M = metabolic b 1 = high-priority parameter, 2 = medium-priority parameter, 3 = low-priority parameter c D = deterministic, S = stochastic N/A = not applicable d Distributions Statistical Parameters:

Lognormal-n: 1= mean, 2 = standard deviation Bounded lognormal-n: 1= mean, 2 = standard deviation, 3 = minimum, 4 = maximum Truncated lognormal-n: 1= mean, 2 = standard deviation, 3 = lower quantile, 4 = upper quantile Bounded normal: 1 = mean, 2 = standard deviation, 3 = minimum, 4 = maximum Triangular: 1 = minimum, 2 = mode, 3 = maximum Uniform: 1 = minimum, 2 = maximum

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 16 Table 6-2: RESRAD Onsite Generated POM Doses and DCGLIR Values by ROC ROC POM Dose (mrem/y per pCi/g)

DCGLIR (pCi/m2)

Am-241 2.56E-04 1.47E+11 C-14 2.44E-03 1.55E+10 Cm-243 7.96E-06 4.74E+12 Cm-244 1.55E-05 2.44E+12 Co-60 1.43E-04 2.64E+11 Cs-137 3.68E-06 1.03E+13 Eu-152 2.94E-05 1.28E+12 Eu-154 3.61E-05 1.05E+12 Fe-55 0.00E+00 0.00E+00 H-3 6.62E-07 3.23E+15 Mn-54 9.30E-06 4.06E+12 Nb-94 3.04E-02 1.24E+09 Ni-63 2.18E-09 1.73E+16 Np-237 5.92E-04 6.38E+10 Pu-238 2.56E-04 1.48E+11 Pu-239 6.17E-03 6.12E+09 Pu-240 5.98E-03 6.31E+09 Pu-241 8.22E-06 4.59E+12 Sb-125 1.58E-06 2.39E+13 Sr-90 2.63E-06 1.44E+13 Tc-99 5.52E-06 6.84E+12

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 17 7.0 Drilling Spoils Scenario 7.1 Scenario Description The drilling spoils scenario assumes that contaminated concrete is captured and mixed with a site soil column extracted during the installation of a hypothetical onsite well. The concrete-soil mixture constitutes the drilling spoils. Assuming the minimum distance to a basement floor maximizes the radionuclide concentration in the drilling spoils. Of the concrete structures to remain in place at the OCS site, the Old Radwaste Building (ORB) has the shallowest floor, 14.4 ft (4.39m) [3.7]. The drill is assumed travel 1 inch (0.0254 m) into the ORB floor before drilling is stopped due to meeting refusal from the concrete. Therefore, the total well drilling depth is assumed to be 17.48 ft (5.33m), which is the sum of the ORB wall, 3-ft cover, and the 1 inch into concrete before refusal. The drilling spoils brought to the surface are treated as soil and are assumed to be spread on the ground at a thickness of 6 inches (0.1524 m).

The industrial use exposure pathways (listed in section 4) are assumed active for the drilling spoils.

7.2 Calculation Method The volume of the drilling spoils was calculated using the equation:

Vds = r2h where Vds = the volume of drilling spoils (m3)

= pi constant r = radius of bore hole (m) h = drilling depth (m)

The area of the drilling spoils at the ground surface (Ads) was calculated by dividing the drilling spoils volume by the assumed thickness of the spoils after spreading:

Ads = Vds/Tds where Vds = the volume of drilling spoils (m3)

Tds = assumed thickness of the drilling spoils at the ground surface (m)

The area concentration activity of contamination on the concrete, Cc (pCi/m2), required to produce a concentration in the drilling spoils equal to 1 pCi/g was determined using the following equation:

Cc = (Vds)(1x106)(Df)(Cds)/ r2 Where Cc = area concentration activity of contamination on the concrete required to produce a concentration in the drilling spoils equal to 1 pCi/g Vds = the volume of drilling spoils (m3) 1x106 = conversion for cm3/m3 Df = density of fill material (g/cm3), assumed to be soil Cds = unit concentration in drilling spoils (1 pCi/g)

= pi constant r = radius of bore hole (m)

The drilling spoils ROC-specific DCGL values (DCGLds,ROC) were calculated as follows:

DCGLds,ROC = (25)(Cc)(AFdsA)/POMROC where 25 = 10CFR20.1402 radiological criterion for unrestricted release (mrem/y)

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 18 Cc = area concentration activity of contamination on the concrete required to produce a concentration in the drilling spoils equal to 1 pCi/g AFdsA = the area factor applicable to Ads (unitless) taken from Table 4 in ENG-OCS-009 [3.8]

POMROC = the peak of the mean dose (mrem/y per pCi/g) taken from Table 4 in ENG-OCS-008

[3.6].

7.3 Input and Calculations for DCGL Calculations 7.4 Input for calculations:

The diameter of the bore hole = 8 inches (0.2032m).

Radius of bore hole = 4 inches (0.1016m)

Height of ORB wall = 14.4 ft (4.39m)

Cover thickness = 3 ft (0.91m)

Concrete depth to refusal = 1 inch (0.0254m)

Density of fill material = 1.5105 g/cm3 [mean density value for soil distribution in ENG-OCS-010]

7.5 The volume and area of the drilling spoils:

Depth of drill column = 5.33m = h Vds = r2h = (3.1415927)(0.2032m/2)2(5.33m) = 0.1728m3 And Ads = (0.1728m3)/(0.1524m) = 1.134 m2 7.6 The area concentration activity of contamination on the concrete, Cc (pCi/m2), required to produce a concentration in the drilling spoils equal to 1 pCi/g:

Cc = (Vds)(1x106)(Df)(Cds)/ r2

= (0.1728m3)(1x106 cm3/m3)(1.5105 g/cm3)(1 pCi/g)/(3.1415297)(0.1016 m)2

= 7.94x107 pCi/m2 per 1 pCi/g 7.7 The drilling spoils ROC-specific DCGL values:

DCGLds,ROC = (25)(Cc)(AFdsA)/POMROC Values for POMROC were taken from Table 4 in ENG-OCS-008 and are provided in column 2 of Table 7-1. The AFdsA values for 1 m2 were from Table 4 in ENG-OCS-009 were applied and are shown in column 3 of table 7-1.

The calculations for DCGLds,ROC were performed using an Excel spreadsheet. The following hand calculation for Am-241 and H-3 confirmed the operability of the spreadsheet.

DCGLds for Am-241 = (25 mrem/y)(7.94x107 pCi/m2 per 1 pCi/g)(12)/(0.0342 mrem/y per 1 pCi/g) = 6.96x1011 pCi/m2. (Note: Difference at the last digit is due to rounding of decimal places retained in Excel spreadsheet.)

DCGLds for H-3 = (25 mrem/y)(7.94x107 pCi/m2 per 1 pCi/g)(764)/(0.000498 mrem/y per 1 pCi/g) = 1.79x1014 pCi/m2.

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 19 Table 7-1: RESRAD-Onsite Generated POM Doses, Area Factors, and DCGLds Values by ROC ROC POMa (mrem/y per pCi/g)

AF1mb DCGLds (pCi/m2)

Am-241 3.42E-02 12 6.97E+11 C-14 1.21E-02 585 9.60E+13 Cm-243 1.38E-01 9

1.30E+11 Cm-244 1.37E-02 16 2.32E+12 Co-60 3.15E+00 9

5.67E+09 Cs-137 6.99E-01 9

2.56E+10 Eu-152 1.42E+00 9

1.26E+10 Eu-154 1.53E+00 9

1.17E+10 Fe-55 2.98E-06 278 1.85E+17 H-3 4.98E-04 45 1.79E+14 Mn-54 7.34E-01 9

2.44E+10 Nb-94 2.01E+00 9

8.89E+09 Ni-63 3.23E-06 176 1.08E+17 Np-237 4.35E-01 9

4.11E+10 Pu-238 2.20E-02 16 1.44E+12 Pu-239 8.17E-02 21 5.11E+11 Pu-240 8.57E-02 21 4.87E+11 Pu-241 1.00E-03 24 4.77E+13 Sb-125 4.50E-01 9

3.97E+10 Sr-90 5.89E-03 11 3.71E+12 Tc-99 1.82E-03 27 2.95E+13 aPOM value from Table 4 in ENG-OCS-008.

bAF value from Table 4 in ENG-OCS-009.

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 20 8.0 Concrete Excavation Scenario 8.1 Scenario Description This scenario assumes that portions of the concrete foundation walls of the building producing the largest concrete volume are excavated, rubblized, spread over the ground surface, and treated as surface soil with the application of the Industrial Use exposure pathways listed in section 6.1. The building walls (assumed 3 ft below grade to account for a cover of site soil) are excavated to the depth sites average depth to groundwater.

The excavated and rubblized concrete is assumed spread to a thickness of 1m over the ground surface.

8.2 Calculation Method 8.2.1 The scenario assumes that excavation is terminated at the groundwater table. Site groundwater data from monitoring wells close to the Reactor Building (RB), Turbine Building (TB), and ORB for the years 2020 - 2023 were used to determine the average depth to groundwater. Groundwater data are provided in Appendix B.

8.2.2 The dimensions for wall lengths and thicknesses for the RB, TB, and ORB were taken from Holltec-00045 Calc-001 and compared to determine the building foundation that would produce the largest volume of concrete if excavated to the average depth of groundwater.

Building wall height accounting for 3-ft cover = depth to groundwater - 3 ft.

8.2.3 The volume of excavated concrete is calculated using the following equation:

Vec = (4-wall total length)(average depth to groundwater-3ft)(wall thickness) 8.2.4 The area of the CZ with a thickness of 1 m was calculated using the following equation:

Acz = Vec/Tcz Where Acz = the area of the CZ (m2)

Vec = the volume of excavated concrete (m3)

Tcz = assumed thickness of the CZ (1m) 8.2.5 The concentration activity in the excavated concrete (pCi/g) resulting from an area contamination on the concrete equal to 1 pCi/m2 was determined using the following equation:

Cec = (Ac)/(tw)(30.48)(WUA)(1x104)(Dc)

Where Cec = unit concentration in the excavated concrete (pCi/g per 1 pCi/m2)

Ac = unit activity over 1 m2 of concrete surface (1 pCi) tw = wall thickness (ft) 30.48 = conversion for cm/ft WUA = unit area of concrete wall (1 m2) 1x104 = conversion for cm2/m2 Df = assumed density of concrete, 2.3 g/cm2, which is the mid-point of density range in 1970 edition of the Radiological Health Handbook 8.2.6 The excavated concrete ROC-specific DCGL values:

DCGLec,ROC = (DCGLsoil,ROC)(AFcz,ROC)/Cec Where DCGLec,ROC = ROC-specific DCGLec (pCi/m2)

DCGLsoil,ROC = ROC-specific DCGL (pCi/g) (from ENG-OCS-003)

AFcz,ROC = the ROC-specific area factor applicable to Acz (unitless) (from ENG-OCS-005)

Cec = unit concentration in the excavated concrete (pCi/g per 1 pCi/m2)

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 21 8.3 Input and Calculations for DCGLec 8.3.1 Site average depth to groundwater = 14.5 ft (calculation provided in Appendix B).

8.3.2 Calculation of Vec by building (wall dimensions from Holtec-00045 Calc-001)

Reactor Building:

4-wall total length = 592 ft Wall thickness = 3.5 ft Wall height = (14.5 ft - 3 ft) = 11.5 ft Vec = (592ft)(3.5ft)(11.5ft) = 23,830 ft3 (value rounded) = 675 m3(value rounded)

Turbine Building:

4-wall total length = 893 ft Wall thickness = 3.0 ft Wall height = (14.5 ft - 3 ft) = 11.5 ft Vec = (893ft)(3.0ft)(11.5ft) = 30,811 ft3 (value rounded) = 872 m3(value rounded)

Old Radwaste Building:

4-wall total length = 239 ft Wall thickness = 2.5 ft Wall height = (14.5 ft - 3 ft) = 11.5 ft Vec = (239ft)(2.5ft)(11.5ft) = 6,872 ft3 (value rounded) = 195 m3(value rounded) 8.3.3 The area of the CZ:

Acz = Vec/h = 872 m3/1m = 872 m2 The AF for a CZ of 872 m2 is 1 for all ROCs (refer to Table 4 in ENG-OCS-005).

8.3.4 The concentration activity in the excavated concrete (pCi/g) resulting from an area contamination on the concrete equal to 1 pCi/m2:

Cec = (Ac)/(tw)(30.48)(WUA)(1x104)(Dc)

= (1 pCi)/(3ft)(30.48)(1m2)(1x104)(2.3 g/cm3)

= 4.75x10-7 pCi/g per 1 pCi/m2 8.3.5 The excavated concrete ROC-specific DCGL values:

DCGLec,ROC = (DCGLsoil,ROC)(AFcz,ROC)/Cec An AF = 1 for all ROCs allow re-writing the above equation:

DCGLec,ROC = (DCGLsoil,ROC)/Cec Values for DCGLsoil,ROC were taken from Table 4 in ENG-OCS-008 and are provided in column 2 of Table 8-1.

The calculations for DCGLec,ROC were performed using an Excel spreadsheet. The following hand calculation for Am-241 and H-3 confirmed the operability of the spreadsheet.

DCGLec for Am-241 = (7.30x102 pCi/g)/(4.75x10-7 pCi/g per pCi/m2) = 1.54x109 pCi/m2 (Note:

Difference is due to rounding of decimal places retained in Excel spreadsheet.)

DCGLec for H-3 = (5.02x104 pCi/g)/(4.75x10-7 pCi/g per pCi/m2) = 1.06x1011 pCi/m2

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 22 Table 8-1: DCGLec Values by ROC ROC DCGLsoil (pCi/g)

DCGLec (pCi/m2)

Am-241 7.30E+02 1.60E+09 C-14 2.07E+03 4.54E+09 Cm-243 1.81E+02 3.97E+08 Cm-244 1.82E+03 3.99E+09 Co-60 7.94E+00 1.74E+07 Cs-137 3.58E+01 7.86E+07 Eu-152 1.76E+01 3.86E+07 Eu-154 1.63E+01 3.58E+07 Fe-55 8.39E+06 1.84E+13 H-3 5.02E+04 1.10E+11 Mn-54 3.41E+01 7.48E+07 Nb-94 1.25E+01 2.74E+07 Ni-63 7.75E+06 1.70E+13 Np-237 5.75E+01 1.26E+08 Pu-238 1.14E+03 2.50E+09 Pu-239 2.37E+02 6.72E+08 Pu-240 3.06E+02 6.41E+08 Pu-241 2.92E+02 5.49E+10 Sb-125 5.56E+01 1.22E+08 Sr-90 4.24E+03 9.30E+09 Tc-99 1.37E+04 3.01E+10

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 23 9.0 Calculation of DCGLw/f Values 9.1 DCGLw/f values were calculated using the following equation:

DCGLw/f = 1/(1/DCGLIR)+(1/DCGLds)+(1/DCGLec)

The calculations for DCGLw/f were performed using an Excel spreadsheet. The following hand calculations for Am-241, Co-60, and H-3 confirmed the operability of the spreadsheet.

DCGLw/f for Am-241 = 1/(1/1.47E+11)+(1/6.97E+11)+(1/1.54E+09) = 1.52E+09 pCi/m2.

DCGLw/f for Co-60 = 1/(1/2.64E+11)+(1/5.67E+09)+(1/1.67E+07) = 1.66E+07 pCi/m2.

DCGLw/f for H-3 = 1/(1/3.22E+15)+(1/1.79E+14)+(1.06E+11) = 1.06E+11 pCi/m2.

Table 9-1: DCGLw/f Values by ROC ROC DCGLIR (pCi/m2)

DCGLds (pCi/m2)

DCGLec (pCi/m2)

DCGLw/f (pCi/m2)

Am-241 1.47E+11 6.97E+11 1.54E+09 1.52E+09 C-14 1.55E+10 9.60E+13 4.35E+09 3.40E+09 Cm-243 4.74E+12 1.30E+11 3.81E+08 3.80E+08 Cm-244 2.43E+12 2.32E+12 3.83E+09 3.82E+09 Co-60 2.64E+11 5.67E+09 1.67E+07 1.66E+07 Cs-137 1.03E+13 2.56E+10 7.53E+07 7.51E+07 Eu-152 1.29E+12 1.26E+10 3.70E+07 3.69E+07 Eu-154 1.05E+12 1.17E+10 3.43E+07 3.42E+07 Fe-55 0.00E+00 1.85E+17 1.76E+13 1.76E+13 H-3 3.22E+15 1.79E+14 1.06E+11 1.06E+11 Mn-54 4.06E+12 2.44E+10 7.17E+07 7.15E+07 Nb-94 1.24E+09 8.89E+09 2.63E+07 2.57E+07 Ni-63 1.73E+16 1.08E+17 1.63E+13 1.63E+13 Np-237 6.38E+10 4.11E+10 1.21E+08 1.20E+08 Pu-238 1.48E+11 5.11E+11 2.40E+09 2.35E+09 Pu-239 6.12E+09 4.87E+11 4.98E+08 4.60E+08 Pu-240 6.32E+09 1.81E+12 6.44E+08 5.84E+08 Pu-241 4.59E+12 4.77E+13 5.26E+10 5.19E+10 Sb-125 2.40E+13 3.97E+10 1.17E+08 1.17E+08 Sr-90 1.44E+13 3.71E+12 8.92E+09 8.89E+09 Tc-99 6.84E+12 2.95E+13 2.88E+10 2.87E+10

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 24 Appendix A Instantaneous Release Scenario POM Doses by ROC

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 25 Am-241 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 09:00 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Am241 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\AM241\\BFM-IU_DCGL_AM241.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 2.561E-04 C-14 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 09:12 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_C14 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\C14\\BFM-IU_DCGL_C14.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 7.017E+01 2.443E-03 Cm-243 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 08:12 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Cm243 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\CM243\\BFM-IU_DCGL_CM243.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 7.960E-06 Cm-244 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 13:49 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Cm244 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\CM244\\BFM-IU_DCGL_CM244.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 1.554E-05 Co-60 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 09:23 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Co60 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\CO60\\BFM-IU_DCGL_CO60.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 1.429E-04 Cs-137 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 09:31 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Cs137 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\CS137\\BFM-IU_DCGL_CS137.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 3.680E-06 Eu-152 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 09:41 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Eu152 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\EU152\\BFM-IU_DCGL_EU152.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 2.938E-05 Eu-154 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 09:49 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Eu154 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\EU154\\BFM-IU_DCGL_EU154.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 3.609E-05 Fe-55 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 10:02 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Fe55 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\FE55\\BFM-IU_DCGL_FE55.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 0.000E+00

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 26 H-3 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 10:13 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_H3 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\H3\\BFM-IU_DCGL_H3.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.304E+00 1.174E-08 Mn-54 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 10:22 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_DCGL_Mn54 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\RESRAD OC IU FILES\\MN54\\BFM-IU_DCGL_MN54.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 9.298E-06 Nb-94 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 11:21 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Nb94_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\NB94\\BFM-IU_NB94_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 3.038E-02 Ni-63 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 13:31 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Ni63_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\NI63\\BFM-IU_NI63_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 2.031E+02 2.178E-09 Np-237 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/09/2023 11:31 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Np237_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\NP237\\BFM-IU_NP237_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 5.380E+01 5.921E-04 Pu-238 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 14:26 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Pu238_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\PU238\\BFM-IU_PU238_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 2.649E+02 2.556E-04 Pu-239 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 14:10 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Pu239_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\PU239\\BFM-IU_PU239_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 6.170E-03 Pu-240 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 11:33 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Pu240 File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\PU240\\BFM-IU_PU240_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 5.977E-03 Pu-241 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 16:31 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Pu241_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\PU241\\BFM-IU_PU241_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+03 8.224E-06 Sb-125 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 13:53 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Sb125_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\SB125\\BFM-IU_SB125_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 27 Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 0.000E+00 1.576E-06 Sr-90 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/08/2023 14:00 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Sr90_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\SR90\\BFM-IU_SR90_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 5.380E+01 2.625E-06 Tc-99 Results:

RESRAD-ONSITE, Version 7.2 T<< Limit = 30 days 11/09/2023 14:35 Page 20 Probabilistic results summary : OCS BFM_Industrial Use_IR_Tc99_DCGL File : C:\\RESRAD_FAMILY\\ONSITE\\7.2\\USERFILES\\BFM INST. RELEASE\\INDUSTRIAL USE\\TC99\\BFM-IU_TC99_DCGL.RAD Peak of the mean dose (averaged over observations) at graphical times Repetition Time of peak mean dose Peak mean dose Years mrem/yr 1 1.000E+00 5.522E-06

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 28 Appendix B Determination of Average Depth to OCS Site Groundwater

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 29 Well Date DTW Gen. Location Average Depth (fbg)

MW-15K-1A 7/26/2021 8.05 West of TB 8.9 MW-15K-1A 10/24/2022 8.21 MW-15K-1A 1/27/2020 8.82 MW-15K-1A 4/25/2022 8.92 MW-15K-1A 5/19/2020 8.97 MW-15K-1A 5/3/2021 9.05 MW-15K-1A 10/18/2021 9.34 MW-15K-1A 8/17/2020 9.53 MW-15K-1A 4/18/2023 9.61 MW-16D 7/26/2021 16.60 North side of RB 17.0 MW-16D 10/24/2022 16.75 MW-16D 10/18/2021 16.85 MW-16D 1/27/2020 17.00 MW-16D 5/3/2021 17.03 MW-16D 4/24/2023 17.11 MW-16D 8/17/2020 17.18 MW-16D 5/19/2020 17.26 MW-16D 4/25/2022 17.43 MW-1A-2A 7/26/2021 14.55 South of ORB 15.5 MW-1A-2A 5/3/2021 14.92 MW-1A-2A 5/19/2020 15.10 MW-1A-2A 1/27/2020 15.20 MW-1A-2A 10/18/2021 15.31 MW-1A-2A 10/24/2022 15.42 MW-1A-2A 4/25/2022 15.92 MW-1A-2A 8/17/2020 16.24 MW-1A-2A 10/12/2020 16.55 MW-1I-1A 7/26/2021 10.82 North of TB 11.8 MW-1I-1A 5/3/2021 11.11 MW-1I-1A 5/19/2020 11.46 MW-1I-1A 1/27/2020 11.67 MW-1I-1A 10/24/2022 11.71 MW-1I-1A 10/18/2021 11.85 MW-1I-1A 4/25/2022 12.28 MW-1I-1A 4/24/2023 12.32 MW-1I-1A 8/17/2020 12.58 MW-1I-1A 10/12/2020 12.62 MW-1I-2A 7/26/2021 11.30 North of TB 12.3 MW-1I-2A 5/3/2021 11.65 MW-1I-2A 10/24/2022 12.03 MW-1I-2A 5/19/2020 12.11 MW-1I-2A 1/27/2020 12.25 MW-1I-2A 10/18/2021 12.35 MW-1I-2A 4/25/2022 12.68 MW-1I-2A 4/20/2023 12.70 MW-1I-2A 8/17/2020 13.04 MW-1I-2A 10/12/2020 13.23 MW-24-3A Farm 5/3/2023 10.16 Not considered - REMP control?

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 30 Well Date DTW Gen. Location Average Depth (fbg)

MW-24-3A Farm 5/3/2021 10.58 MW-24-3A Farm 10/24/2022 10.62 MW-24-3A Farm 1/27/2020 10.67 MW-24-3A Farm 4/25/2022 10.70 MW-24-3A Farm 5/19/2020 10.90 MW-24-3A Farm 2/8/2021 10.94 MW-24-3A Farm 10/18/2021 11.00 MW-24-3A Farm 1/27/2020 11.24 MW-24-3A Farm 10/12/2020 11.54 MW-52 10/12/2020 9.80 Not considered - too far west MW-52 8/17/2020 10.20 MW-52 10/24/2022 10.59 MW-52 10/18/2021 10.64 MW-52 5/3/2021 10.65 MW-52 1/27/2020 10.68 MW-52 4/20/2023 10.80 MW-52 4/25/2022 10.81 MW-52 5/19/2020 10.96 MW-53 10/24/2022 10.17 West of TB 10.9 MW-53 4/25/2022 10.70 MW-53 1/27/2020 10.71 MW-53 5/3/2021 10.85 MW-53 5/19/2020 10.90 MW-53 10/12/2020 11.05 MW-53 10/18/2021 11.20 MW-53 4/18/2023 11.30 MW-53 8/17/2020 11.34 MW-54 10/12/2020 5.53 Not considered - too far west MW-54 1/27/2020 7.00 MW-54 8/17/2020 7.25 MW-54 10/24/2022 7.54 MW-54 10/18/2021 7.75 MW-54 4/25/2022 7.80 MW-54 5/3/2021 7.82 MW-54 4/20/2023 8.11 MW-54 5/19/2020 8.20 MW-55 10/12/2020 9.86 West of TB 10.6 MW-55 8/17/2020 10.25 MW-55 10/24/2022 10.42 MW-55 7/26/2021 10.43 MW-55 1/27/2020 10.61 MW-55 10/18/2021 10.80 MW-55 4/18/2022 10.85 MW-55 4/25/2022 10.90 MW-55 5/3/2021 10.93 MW-55 5/19/2020 11.25 MW-56I 10/24/2022 10.65 West of TB 11.1 MW-56I 8/17/2020 10.68

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 31 Well Date DTW Gen. Location Average Depth (fbg)

MW-56I 7/26/2021 10.91 MW-56I 1/27/2020 11.02 MW-56I 10/18/2021 11.10 MW-56I 10/12/2020 11.11 MW-56I 4/18/2023 11.15 MW-56I 5/3/2021 11.45 MW-56I 4/25/2022 11.60 MW-56I 5/19/2020 11.65 MW-57I 10/12/2020 10.10 Not considered - too far west MW-57I 8/17/2020 10.45 MW-57I 10/24/2022 10.75 MW-57I 10/18/2021 10.92 MW-57I 4/20/2023 10.95 MW-57I 7/26/2021 11.03 MW-57I 5/19/2020 11.08 MW-57I 5/3/2021 11.10 MW-57I 1/27/2020 11.20 MW-57I 4/25/2022 11.23 MW-59I 10/12/2020 12.47 West of TB 13.1 MW-59I 10/24/2022 12.79 MW-59I 8/17/2020 12.90 MW-59I 7/26/2021 13.15 MW-59I 10/18/2021 13.15 MW-59I 4/18/2023 13.15 MW-59I 1/27/2020 13.30 MW-59I 5/3/2021 13.40 MW-59I 5/19/2020 13.42 MW-59I 4/25/2022 13.47 MW-61I 10/24/2022 10.37 West of TB 10.9 MW-61I 10/12/2020 10.43 MW-61I 8/17/2020 10.45 MW-61I 4/18/2023 10.60 MW-61I 1/27/2020 10.84 MW-61I 4/25/2022 10.95 MW-61I 10/18/2021 11.05 MW-61I 7/26/2021 11.10 MW-61I 5/3/2021 11.30 MW-61I 5/19/2020 11.47 MW-62 10/18/2021 11.65 North of TB 13.3 MW-62 10/12/2020 12.82 MW-62 7/26/2021 12.90 MW-62 1/27/2020 13.17 MW-62 8/17/2020 13.36 MW-62 5/19/2020 13.51 MW-62 10/24/2022 13.56 MW-62 5/3/2021 13.75 MW-62 4/25/2022 13.98 MW-62 4/24/2023 14.41

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 32 Well Date DTW Gen. Location Average Depth (fbg)

MW-64 10/12/2020 9.85 Not considered - too far west MW-64 8/17/2020 10.43 MW-64 10/24/2022 10.62 MW-64 7/26/2021 10.65 MW-64 10/18/2021 10.80 MW-64 5/3/2021 11.00 MW-64 4/20/2023 11.02 MW-64 1/27/2020 11.06 MW-64 4/25/2022 11.15 MW-64 5/19/2020 11.30 MW-65 5/19/2020 11.51 West of TB 12.2 MW-65 10/24/2022 11.64 MW-65 10/12/2020 11.90 MW-65 8/17/2020 12.05 MW-65 7/26/2021 12.13 MW-65 10/18/2021 12.27 MW-65 4/18/2023 12.41 MW-65 5/3/2021 12.45 MW-65 4/25/2022 12.53 MW-65 1/27/2020 12.68 MW-67 10/24/2022 18.22 inside TB footprint 18.6 MW-67 7/26/2021 18.30 MW-67 5/19/2020 18.44 MW-67 4/24/2023 18.47 MW-67 8/17/2020 18.59 MW-67 1/27/2020 18.68 MW-67 4/25/2022 18.78 MW-67 10/18/2021 18.85 MW-67 5/3/2021 18.87 MW-67 10/12/2020 19.03 MW-68I 8/17/2020 17.25 South of RB 17.4 MW-68I 10/12/2020 17.51 MW-71 7/26/2021 15.62 South of RB 16.2 MW-71 10/24/2022 15.64 MW-71 1/27/2020 16.03 MW-71 10/18/2021 16.05 MW-71 5/3/2021 16.10 MW-71 5/19/2020 16.35 MW-71 8/17/2020 16.40 MW-71 4/24/2023 16.43 MW-71 4/25/2022 16.61 MW-71 10/12/2020 16.81 MW-72 10/24/2022 17.92 North of RB 18.2 MW-72 7/26/2021 17.94 MW-72 1/27/2020 17.98 MW-72 10/18/2021 18.03 MW-72 8/17/2020 18.05 MW-72 5/3/2021 18.20

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 33 Well Date DTW Gen. Location Average Depth (fbg)

MW-72 4/24/2023 18.21 MW-72 5/19/2020 18.30 MW-72 4/25/2022 18.42 MW-72 10/12/2020 18.50 W-10 7/26/2021 17.57 South of RB 17.8 W-10 8/17/2020 17.61 W-10 1/27/2020 17.64 W-10 4/24/2023 17.75 W-10 10/24/2022 17.79 W-10 10/18/2021 17.80 W-10 10/12/2020 17.88 W-10 5/3/2021 17.90 W-10 4/25/2022 18.09 W-10 5/19/2020 18.15 W-12 7/26/2021 13.20 North of RB 13.9 W-12 4/25/2022 13.52 W-12 5/3/2021 13.60 W-12 10/24/2022 13.76 W-12 10/18/2021 13.80 W-12 5/19/2020 13.85 W-12 1/27/2020 13.90 W-12 4/24/2023 14.20 W-12 8/17/2020 14.45 W-12 10/12/2020 14.85 W-13 10/24/2022 19.02 North of RB 19.5 W-13 8/17/2020 19.10 W-13 7/26/2021 19.22 W-13 1/27/2020 19.26 W-13 10/18/2021 19.37 W-13 4/24/2023 19.47 W-13 4/25/2022 19.48 W-13 10/12/2020 19.52 W-13 5/19/2020 19.73 W-13 5/3/2021 20.65 W-14 10/24/2022 17.70 NW of ORB 17.3 W-14 8/17/2020 17.90 W-14 7/26/2021 17.95 W-14 1/27/2020 17.96 W-14 4/24/2023 18.11 W-14 10/18/2021 18.12 W-14 5/3/2021 18.30 W-14 4/25/2022 18.31 W-14 5/19/2020 18.45 W-15 7/26/2021 10.35 NW of ORB 11.4 W-15 5/3/2021 10.60 W-15 1/27/2020 10.87 W-15 10/18/2021 11.13 W-15 4/25/2022 11.37

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 34 Well Date DTW Gen. Location Average Depth (fbg)

W-15 10/24/2022 11.41 W-15 5/19/2020 11.80 W-15 4/24/2023 12.01 W-15 8/17/2020 12.07 W-15 10/12/2020 12.45 W-16 7/26/2021 8.07 Not considered - too far north W-16 5/3/2021 8.33 W-16 5/19/2020 8.53 W-16 1/27/2020 8.65 W-16 10/18/2021 8.87 W-16 10/24/2022 9.00 W-16 4/25/2022 9.17 W-16 4/24/2023 9.23 W-16 8/17/2020 9.71 W-16 10/12/2020 10.30 W-1A 8/17/2020 19.25 Not considered - outside PA W-1A 10/24/2022 19.29 W-1A 1/27/2020 19.62 W-1A 10/18/2021 19.72 W-1A 10/12/2020 19.75 W-1A 4/24/2023 20.09 W-1A 4/25/2022 20.34 W-1A 5/3/2021 20.46 W-1A 5/19/2020 20.56 W-24 7/26/2021 12.58 South of TB 13.7 W-24 10/24/2022 12.72 W-24 5/3/2021 13.12 W-24 1/27/2020 13.30 W-24 5/19/2020 13.50 W-24 10/18/2021 13.73 W-24 4/25/2022 14.27 W-24 10/12/2020 14.65 W-24 8/17/2020 14.75 W-24 4/24/2023 14.77 W-3 7/26/2021 14.25 West of TB 15.4 W-3 10/18/2021 14.35 W-3 10/24/2022 14.56 W-3 5/3/2021 15.26 W-3 4/20/2023 15.58 W-3 4/25/2022 15.83 W-3 10/12/2020 15.86 W-3 1/27/2020 15.95 W-3 5/19/2020 16.08 W-3 8/17/2020 16.25 W-34 10/24/2022 17.56 South of TB 18.0 W-34 7/26/2021 17.73 W-34 10/12/2020 17.76 W-34 10/18/2021 17.98

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 35 Well Date DTW Gen. Location Average Depth (fbg)

W-34 8/17/2020 18.00 W-34 1/27/2020 18.10 W-34 5/3/2021 18.15 W-34 4/24/2023 18.16 W-34 4/25/2022 18.34 W-34 5/19/2020 18.35 W-4 8/17/2020 16.20 West of TB 16.7 W-4 7/26/2021 16.45 W-4 1/27/2020 16.50 W-4 10/12/2020 16.52 W-4 10/18/2021 16.56 W-4 10/24/2022 16.62 W-4 4/20/2023 16.65 W-4 4/25/2022 16.92 W-4 5/3/2021 17.02 W-4 5/19/2020 17.15 W-4A 10/24/2022 12.40 Not considered - too far SE W-4A 1/27/2020 12.51 W-4A 1/27/2020 12.52 W-4A 2/8/2021 12.55 W-4A 10/18/2021 12.70 W-4A 4/24/2023 12.70 W-4A 10/12/2020 12.71 W-4A 5/3/2021 12.76 W-4A 4/25/2022 12.81 W-4A 5/19/2020 12.98 W-5 7/26/2021 11.61 Not considered - too far NW W-5 5/3/2021 12.15 W-5 10/24/2022 12.27 W-5 5/19/2020 12.30 W-5 1/27/2020 12.35 W-5 10/18/2021 12.75 W-5 4/25/2022 12.82 W-5 4/24/2023 13.00 W-5 10/12/2020 13.05 W-5 8/17/2020 13.10 W-6 8/17/2020 19.64 Not considered - too far NW W-6 7/26/2021 19.95 W-6 10/12/2020 20.03 W-6 1/27/2020 20.05 W-6 4/24/2023 20.08 W-6 10/18/2021 20.15 W-6 10/24/2022 20.20 W-6 4/25/2022 20.36 W-6 5/3/2021 20.55 W-6 5/19/2020 20.60 W-9 10/24/2022 14.34 South of RB 15.2 W-9 7/26/2021 14.45

BHI Energy ENG-OCS-013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1 Page 36 Well Date DTW Gen. Location Average Depth (fbg)

W-9 5/3/2021 14.91 W-9 1/27/2020 15.03 W-9 10/18/2021 15.05 W-9 5/19/2020 15.15 W-9 4/25/2022 15.58 W-9 4/24/2023 15.66 W-9 8/17/2020 15.70 W-9 10/12/2020 16.00 Average All 13.89 Aver. for wells near TB, RB, and ORB 14.5 fbg