ML24214A060

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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
ML24214A209 List:
References
HDI-OC-24-018 OCS-013, Rev 1
Download: ML24214A060 (1)
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Text

ENGINEERING CALCULATION Basement Fill Model:

Calculation of DCGLW/F Values Assuming Industrial Use Scenario Exposure Pathways

Oyster Creek Station ENG-OC S-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

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 -01 2, 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. Calculation s 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

Page 2 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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, Np-237 Th-229, U-233 Pu-239, U-235 Cm-244 Pu-240, Ra-228, Th-228, Pu-238 Pb-210, Po-210, Ra-226, Th-232, U-236 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.

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

site grade 3f t ( 0. 91m ) co v e r

UZ : 11. 5f t ( 3. 5m )

GW t a b l e @14. 5f t ( 4. 42m ) 26. 74% i n UZ GW flow----->

SZ: 31. 5f t ( 9. 6m ) 73. 26% i n SZ

<- - - - C Z w i d t h 145. 3 f t ( 44. 3m = L P A F ) - - >I 1-~1 = C V 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 75 th 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 25 th 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, c alculations of the ROC-specific DCGL values relied on 2 other calculations.

Page 4 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 m 2 of concrete surface (1 pCi)

Vfill = unit volume of fill material (1 m3) 1E6 = conversion factor (cm 3 per m3)

Dfill = density of fill material (g/cm 3)

Calculation of ROC-specific DCGL IR 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 ÷ (POM ROC 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 -01 2).

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/m 2 using equation 6-1:

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

The mean value (1.5105 g/cm 3) 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 DCGL IR 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 Page 5 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 DCGL IR,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/m 2)

= 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 Distribution's Statistical Median/

Parameter (unit) Typea Priorityb Treatmentc Value/Distribution Basis Parametersd Mean 1 2 3 4 Soil Concentrations Basic radiation dose P 3 D 25 10 CFR 20.1402 NR NR NR NR limit (mrem/y)

Initial principal P 2 D 1 Unit Value NR NR NR NR radionuclide (pCi/g)

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 3.71E+03 (CZ)75th percentile value

D 2.69E+02 (UZ) 25th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 6.91 1.95 0.001 0.999 1000 Am-243 P 1 D 3.71E+03 (CZ)75th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 6.91 1.95 0.001 0.999 1000 C-14 P 1 D 7.11E+01 (CZ)75th percentile value

D 6.14E+00 (UZ) 25th percentile value

S Truncated lognormal-n 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

Page 6 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario

Co-60 P 1 D 3.71E+01 (CZ)25th percentile value

S Truncated lognormal-n 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 1.41E+04 (CZ)75th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 6.86 4.01 0.001 0.999 955 Eu-154 P 1 D 1.41E+04 (CZ)75th percentile value

S Truncated lognormal-n 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 5.78E+03 (CZ)75th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 6.89 2.64 0.001 0.999 980 Nb-94 P 1 D 3.80E+03 (CZ)75th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 7.31 1.39 0.001 0.999 1500 Ni-63 P 1 D 2.77E+01 (UZ)25th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 4.87 2.3 0.001 0.999 130 Np-237 P 1 D 3.56E+01 (CZ)75th percentile value

D 5.49+00 (UZ) 25th percentile value

S Truncated lognormal-n 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 1.02E+03 (CZ) 75th percentile value

D 1.57E+02 (UZ) 25th percentile value

S Truncated lognormal -n ANL/EVS/TM -14/4 5.99 1.39 0.001 0.999 400 Pu-240 P 1 D 1.02E+03 (CZ) 75th percentile value

D 1.57E+02 (UZ) 25th percentile value

S Truncated lognormal -n 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

Page 7 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario

Sb-125 P 1 D 5.64E+01 (CZ)75th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 2.83 1.79 0.001 0.999 17 Sr-90 P 1 D 6.58E+00 (CZ & UZ)25th percentile value3.09 1.79 0.001 0.999 22

S Truncated lognormal-n ANL/EVS/TM-14/4 Tc-99 P 1 D 1.90E- 02 (UZ) 25th percentile value

S Truncated lognormal-n 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 2.07E+01 (CZ & UZ)25th percentile value

S Truncated lognormal-n 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 2.07E+01 (UZ)25th percentile value

S Truncated lognormal-n ANL/EVS/TM-14/4 4.7 2.48 0.001 0.999 110 Initial concentration P 3 D 0 Ground water NR NR NR NR of radionuclides uncontaminated present in groundwater (pCi/l)

Calculation Times Time since placement P 3 D 0 NR NR NR NR of material (y)

Time for calculations P 3 D 0, 1, 3, 10, 30, 100, 300, RESRAD Default NR NR NR NR (y) 1000 Contaminated Zone Area of contaminated P 2 D 1539.6 Based on contaminated NR NR NR NR zone (m 2) volume and height of RB wall.

Thickness of P 2 D 13.1 CZ thickness set to RB NR NR NR NR contaminated zone wall height.

(m)

Length parallel to P 2 D 44.3 Set to diameter of CZ. NR NR NR NR aquifer flow (m)

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; NR NR NR NR average groundwater depths recorded for wells around the RB, TB, and ORB.

Cover and Contaminated Zone Hydrological Data Cover depth (m) P 2 D 0.91 3ft cover assumed. NR NR NR NR

Page 8 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 1.40E+00 (C-14, Co-60, 25th percentile value Cs-137, Eu-152, Eu-154, Mn-54, Nb-94, Np-237, Pu-238, Pu-240, Sb-125, Sr-90)

S Truncated Normal (all Site soil type = sand (2017 1.5105 0.159 0.001 0.999 1.5105 ROCs not listed above) Hydrogeologic Investigation Report).

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

Cover erosion rate P 2 D 6E-04 Assumed final site grade NR NR NR NR (m/y) is level. Input for erosion rate = NUREG/CR-7267 erosion rate for site with shallow slope (i.e.,

relatively level)

Density of P 1 S Truncated Normal Site soil type = sand (2017 1.5105 0.159 0.001 0.999 1.5105 contaminated zone Hydrogeologic (g/cm3) Investigation Report).

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

Contaminated zone P 2 D 6E-04 Assumed same as cover. NR NR NR NR erosion rate (m/y)

Contaminated zone P 2 S Bounded Normal NUREG/CR-7267 0.43 0.06 0.2446 0.6154 0.43 total porosity distribution for site soil type -sand Contaminated zone P 3 D 0.18 Value based on site-NR NR NR NR field capacity specific soil type (sand);

calculated using equation in NUREG/CR-7267 Contaminated zone P 2 D 2741 2017 Hydrogeologic NR NR NR NR hydraulic Investigation Report conductivity (m/y)

Contaminated zone b P 2 S Bounded NUREG/CR-7267 - 0.0253 0.216 0.501 1.90 0.975 parameter Log Normal n distribution for site soil type - sand Humidity in air P 3 D 6.6 From Regional and Site-NR NR NR NR (g/m3) Specific Absolute Humidity Data for Use in Tritium Dose Calculations.

Evapotranspiration P 2 D 5.62E-01 (Tc-99) 25th percentile value coefficient S Uniform (all other ROCs) NUREG/CR-7267 0.5 0.75 0.625 distribution Average annual wind P 2 D 3.13 Internet search: NR NR NR NR speed (m/s) https://www.windfinder.co m/windstatistics/oyster_cre ek_barnegat_bay Precipitation (m/y) P 2 D 1.4 Annual Report on the NR NR NR NR Meteological Program at Oyster Creek Generating Station - average annual precipitation for 2015 through 2020

Page 9 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 0 0.08 0.04 using methodology described in Data Collection Handbook and NUREG/CR-6697 Irrigation mode B 3 D Overhead Overhead irrigation is NR NR NR NR common practice for crops in U.S.

Runoff coefficient P 2 D 0.2 Value determined using NR NR NR NR methodology described in Data Collection Handbook and NUREG/CR-7267 Watershed area for P 3 D 1.01E+08 NJ-GeoWeb (NJDEP NR NR NR NR nearby stream or BGIS) pond (m2)

Accuracy for - 3 D 1.00E-03 RESRAD Default NR NR NR NR water/soil computations Saturated Zone Hydrological Data Density of saturated P 1 S Truncated Normal NUREG/CR-7267 1.5105 0.159 0.001 0.999 1.5105 zone (g/cm 3) distribution for site soil type -sand Saturated zone total P 1 S Truncated Normal NUREG/CR-7267 0.43 0.06 0.001 0.999 0.43 porosity distribution for site soil type -sand Saturated zone P 1 D 0.25 2017 Hydrogeologic NR NR NR NR effective porosity Investigation Report Saturated zone field P 3 D 0.18 Value based on site-NR NR NR NR capacity specific soil type (sand);

calculated using equation in NUREG/CR-7267 Saturated zone P 1 D 2741 2017 Hydrogeologic NR NR NR NR hydraulic Investigation Report conductivity (m/y)

Saturated zone P 2 D 1.75E-02 (H-3 & Nb-94) 25th percentile value hydraulic gradient S Uniform 2017 Hydrogeologic 0.01 0.04 0.025 Investigation Report Saturated zone b P 2 S N/A Input not required when NR NR NR NR parameter CZ is in SZ Water table drop rate P 3 D 0 CZ in SZ NR NR NR NR (m/y)

Well pump intake P 2 D 9.6 Set to the distance from the NR NR NR NR depth (m below water water table to the lower table) boundary of contamination in the aquifer at the downgradient edge of the contaminated zone.

Model: P 3 D ND ND model recommended NR NR NR NR Nondispersion (ND) for contaminant areas or Mass-Balance >1,000 m2 (MB)

Well pumping rate P 2 S N/A Input not required. NR NR NR NR (m3/y)

Unsaturated Zone Hydrological Data Unsaturated zones P 3 D 1 NR NR NR NR Unsat. zone 1, P 1 D 3.5 11.5 ft (3.5m) of CZ NR NR NR NR thickness (m) located between cover and groundwater table.

Unsat. zone 1, soil P 2 S Truncated Normal NUREG/CR-7267 1.5105 0.159 0.001 0.999 1.5105 density (g/cm3) distribution for site soil type - sand Page 10 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Unsat. zone 1, total P 2 S Truncated Normal NUREG/CR-7267 0.43 0.06 0.001 0.999 0.43 porosity distribution for site soil type - sand Unsat. zone 1, P 2 D 0.25 2017 Hydrogeologic NR NR NR NR effective porosity Investigation Report Unsat. zone 1, field P 3 D 0.18 Value based on site-NR NR NR NR capacity specific soil type (sand);

calculated using equation in NUREG/CR-7267 Unsat. zone 1, P 2 D 2741 2017 Hydrogeologic NR NR NR NR hydraulic Investigation Report conductivity (m/y)

Unsat. zone 1, soil-P 2 S Bounded NUREG/CR-7267 - 0.0253 0.216 0.501 1.90 0.975 specific b parameter Log Normal n distribution for site soil type - sand Occupancy Inhalation rate (m3/y) B 3 D 8400 NUREG/CR-7267 NR NR NR NR

Mass loading for P 2 S Continuous linear NUREG/CR-7267 2.3E-5 inhalation (g/m3)

Exposure duration B 3 D 30 RESRAD Default NR NR NR NR Indoor dust filtration P 2 S Uniform NUREG/CR-7267 0.15 0.95 0.55 factor Shielding factor, P 2 D 4.00E-01 (Co-60, Cs-137, 75th percentile value external gamma & Mn-54)

S Bounded lognormal-n (all NUREG/CR-7267 -1.3 0.59 0.044 1 0.2725 other ROCs)

Fraction of time spent B 3 D 0.03 Fraction of calendar year NR NR NR NR indoors assuming 1h/work day for daily work breaks Fraction of time spent B 3 D 0.2 Fraction of calendar year NR NR NR NR outdoors assuming 7h/work day for outside tasks Shape factor flag, P 3 D Circular Circular contaminated zone NR NR NR NR external gamma assumed Ingestion, Dietary Fruits, vegetables, B 2 D N/A Input not required - plant NR NR NR NR grain consumption ingestion pathway inactive (kg/y)

Leafy vegetable B 3 D N/A Input not required - plant NR NR NR NR consumption (kg/y) ingestion pathway inactive Milk consumption B 2 D N/A Input not required - milk NR NR NR NR (L/y) ingestion pathway inactive Meat and poultry B 3 D N/A Input not required - meat NR NR NR NR consumption (kg/y) ingestion pathway inactive Fish consumption B 3 D 20.6 NUREG/CR-5512, Vol. 3 NR NR NR NR (kg/y)

Other seafood B 3 D 0.9 RESRAD Default NR NR NR NR consumption (kg/y)

Soil ingestion rate B 2 D Triangular NUREG/CR-7267 0 18.3 36.5 18.3 (g/yr)

Drinking water intake B 2 D N/A Input not required - NR NR NR NR (L/y) drinking water pathway inactive Contamination P 3 D N/A Input not required - NR NR NR NR fraction of drinking drinking water pathway water inactive Contamination P 3 N/A Input not required - water fraction of household pathway inactive water Page 11 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Contamination P 3 D N/A Input not required - NR NR NR NR fraction of livestock drinking water/ingestion water pathways inactive Contamination P 3 D N/A Input not required - plant NR NR NR NR fraction of irrigation ingestion pathway inactive water Contamination P 2 D 6.10E-01 (H-3 & Tc-99) 75th percentile value fraction of aquatic food S Triangular (all other NUREG/CR-7267 0 0.39 1.0 0.39 ROCs)

Contamination P 3 D N/A Input not required - plant NR NR NR NR fraction of plant food ingestion pathway inactive Contamination P 3 D N/A Input not required - meat NR NR NR NR fraction of meat ingestion pathway inactive Contamination P 3 D N/A Input not required - milk NR NR NR NR fraction of milk ingestion pathway inactive Ingestion, Non-Dietary Livestock fodder M 3 D N/A Input not required - meat NR NR NR NR intake for meat (kg/d) ingestion pathway inactive Livestock fodder M 3 D N/A Input not required - milk NR NR NR NR intake for milk (kg/d) ingestion pathway inactive Livestock water M 3 D N/A Input not required - water NR NR NR NR intake for meat (L/d) ingestion pathway inactive Livestock water M 3 D N/A Input not required - milk NR NR NR NR intake for milk (L/d) ingestion pathway inactive Livestock soil intake M 3 D N/A Input not required - meat NR NR NR NR (kg/d) ingestion pathway inactive Mass loading for P 3 D N/A Input not required - plant NR NR NR NR foliar deposition ingestion pathway inactive (g/m3)

Depth of soil mixing P 2 D 3.40E-01 (Am-241, Cm-75th percentile value layer (m) 243, Cm-244, Pu-239, &

Pu-241)

S Triangular (all other NUREG/CR-7267 0 0.15 0.6 0.23 ROCs)

Depth of roots (m) P 1 S N/A Input not required - plant 0.3 4 1.85 ingestion pathway inactive Drinking water P 3 D N/A Input not required - NR NR NR NR fraction from ground drinking water ingestion water pathway inactive Household water P 3 N/A Input not required -

fraction from ground drinking water pathway water inactive Livestock water P 3 D N/A Input not required - NR NR NR NR fraction from ground drinking water/meat water ingestion pathways inactive Irrigation fraction P 3 D N/A Input not required - NR NR NR NR from ground water drinking water pathway inactive Wet weight crop P 2 S N/A Input not required - plant 0.56 0.48 0.001 0.999 1.75 yield for Non-Leafy ingestion pathway inactive (kg/m2)

Wet weight crop P 3 D N/A Input not required - plant NR NR NR NR yield for Leafy ingestion pathway inactive (kg/m2)

Wet weight crop P 3 D N/A Input not required - meat NR NR NR NR yield for Fodder ingestion pathway inactive (kg/m2)

Growing Season for P 3 D N/A Input not required - plant NR NR NR NR Non-Leafy (y) ingestion pathway inactive Page 12 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Growing Season for P 3 D N/A Input not required - plant NR NR NR NR Leafy (y) ingestion pathway inactive Growing Season for P 3 D N/A Input not required - meat NR NR NR NR Fodder (y) ingestion pathway inactive Translocation Factor P 3 D N/A Input not required - plant NR NR NR NR for Non-Leafy ingestion pathway inactive Translocation Factor P 3 D N/A Input not required - plant NR NR NR NR for Leafy ingestion pathway inactive Translocation Factor P 3 D N/A Input not required - meat NR NR NR NR for Fodder ingestion pathway inactive Weathering Removal P 2 S N/A Input not required - plant 5.1 18 84 33 Constant for ingestion pathway inactive Vegetation (1/y)

Wet Foliar P 3 D N/A Input not required - plant NR NR NR NR Interception Fraction ingestion pathway inactive for Non-Leafy Wet Foliar P 2 S N/A Input not required - plant 0.06 0.67 0.95 0.58 Interception Fraction ingestion pathway inactive for Leafy Wet Foliar P 3 D N/A Input not required - meat NR NR NR NR Interception Fraction ingestion pathway inactive for Fodder Dry Foliar P 3 D N/A Input not required - plant NR NR NR NR Interception Fraction ingestion pathway inactive for Non-Leafy Dry Foliar P 3 D N/A Input not required - plant NR NR NR NR Interception Fraction ingestion pathway inactive for Leafy Dry Foliar P 3 D N/A Input not required - meat NR NR NR NR Interception Fraction ingestion pathway inactive for Fodder Storage times of contaminated foodstuffs (days):

Fruits, non-leafy B 3 D N/A Input not required - plant NR NR NR NR vegetables, and grain ingestion pathway inactive Leafy vegetables B 3 D N/A Input not required - plant NR NR NR NR ingestion pathway inactive Milk B 3 D N/A Input not required - milk NR NR NR NR ingestion pathway inactive Meat and poultry B 3 D N/A Input not required - meat NR NR NR NR ingestion pathway inactive Fish B 3 D 7 RESRAD Default NR NR NR NR Crustacea and B 3 D 7 RESRAD Default NR NR NR NR mollusks Well water B 3 D N/A Input not required - NR NR NR NR drinking water pathway inactive Surface water B 3 D N/A Input not required drinking NR NR NR NR water pathway inactive Livestock fodder B 3 D N/A Input not required - meat NR NR NR NR ingestion pathway inactive Special Radionuclides (C-14)

C-12 concentration P 3 D 2.00E-05 RESRAD Default NR NR NR NR in water (g/cm3)

C-12 concentration P 3 D 3.00E-02 RESRAD Default NR NR NR NR in contaminated soil (g/g)

Fraction of P 3 D 2.00E-02 RESRAD Default NR NR NR NR vegetation carbon from soil

Page 13 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Input Values for DCGL Analysis: OC BFM Instantaneous Release (In Situ) Scenario to Support the Industrial Use Compliance Scenario Fraction of P 3 D 9.80E-01 RESRAD Default NR NR NR NR vegetation carbon from air C-14 evasion layer P 2 S Triangular NUREG/CR-7267 0.2 0.3 0.6 0.3 thickness in soil (m)

C-14 evasion flux P 3 D 7.00E-07 RESRAD Default NR NR NR NR rate from soil (1/s)

C-12 evasion flux P 3 D 1.00E-10 RESRAD Default NR NR NR NR rate from soil (1/s)

Fraction of grain in B 3 D 0.2500 NUREG/CR-7267 NR NR NR NR beef cattle feed Fraction of grain in B 3 D 0.1000 NUREG/CR-7267 NR NR NR NR milk cow feed 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

Page 14 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 17 RESRAD Default NR NR NR NR points for dose 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

Page 15 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Table 6-2: RESRAD Onsite Generated POM Doses and DCGLIR Values by ROC POM Dose (mrem/y per DCGLIR ROC pCi/g) (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

Page 16 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 constitu tes 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. The refore, 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 eq uation:

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 (A ds) 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 = (V ds)(1x106)(D f)(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 cm 3/m3 Df = density of fill material (g/cm 3), 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 (DCGL ds,ROC ) were calculated as follows:

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

Page 17 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 (4.3 9m)
  • 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) = 0.1728m 3 And Ads = (0.1728m3)/(0.1524m) = 1.134 m 2 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 = (V ds)(1x106)(Df)(Cds)/ r2

= (0.1728m3)(1x106 cm3/m3)(1.5105 g/cm3)(1 pCi/g)/(3.14 15297)(0.1016 m)2

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

DCGLds,ROC = (25)(C c)(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 AF dsA 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 )(7.94x10 7 pCi/m2 per 1 pCi/g)(12)/(0. 0342 mrem/y per 1 pCi/g) = 6.96x10 11 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)(7.94x10 7 pCi/m2 per 1 pCi/g)(764 )/(0.000498 mrem/y per 1 pCi/g) = 1.79x10 14 pCi/m2.

Page 18 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Table 7-1: RESRAD-Onsite Generated POM Doses, Area Factors, and DCGLds Values by ROC

POMa DCGLds ROC (mrem/y per pCi/g) AF1mb (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 -00 9.

Page 19 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 excav ated 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 concreteif excav ated 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 m 2) 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 = (DCGL soil,ROC)(AFcz,ROC )/Cec Where DCGLec,ROC = ROC-specific DCGL ec (pCi/m2)

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

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

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

Page 20 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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 ft 3 (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 = V ec/h = 872 m 3/1m = 872 m 2 The AF for a CZ of 872 m 2 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 = (A c)/(tw)(30.48)(WUA)(1x104)(Dc)

= (1 pCi)/(3ft)(30.48)(1m 2)(1x104)(2.3 g/cm 3)

= 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-00 8 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 = (7.30x10 2 pCi/g)/(4.75x10-7 pCi/g per pCi/m2) = 1.54 x10 9 pCi/m2 (Note:

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

DCGLec for H-3 = (5.02x10 4 pCi/g)/(4.75x10 -7 pCi/g per pCi/m2) = 1.06x1011 pCi/m2

Page 21 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Table 8-1: DCGL ec Values by ROC

DCGLsoil DCGLec ROC (pCi/g) (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

Page 22 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

9.0 Calculation of DCGLw/f Values 9.1 DCGLw/f values were calculated using the following equation:

DCGLw/f = 1/(1/DCGL IR)+(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) = 1.0 6E+11 pCi/m2.

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

Page 23 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Appendix A

Instantaneous Release Scenario POM Doses by ROC

Page 24 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

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

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

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

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

Page 27 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Appendix B

Determination of Average Depth to OCS Site Groundwater

Page 28 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (fbg)

MW-15K -1A 7/26/2021 8.05 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 West of TB 8.9 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 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 North side of RB 17.0 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 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 South of ORB 15.5 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 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 North of TB 11.8 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 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 North of TB 12.3 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?

Page 29 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (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 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 Not considered - too far west 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 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 West of TB 10.9 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 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 Not considered - too far west 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 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 West of TB 10.6 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 Page 30 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (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 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 Not considered - too far west 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 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 West of TB 13.1 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 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 West of TB 10.9 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 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 North of TB 13.3 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 Page 31 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (fbg)

MW-64 10/12/2020 9.85 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 Not considered - too far west 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 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 West of TB 12.2 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 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 inside TB footprint 18.6 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 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 South of RB 16.2 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 MW-72 7/26/2021 17.94 MW-72 1/27/2020 17.98 North of RB 18.2 MW-72 10/18/2021 18.03 MW-72 8/17/2020 18.05 MW-72 5/3/2021 18.20 Page 32 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (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 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 South of RB 17.8 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 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 North of RB 13.9 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 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 North of RB 19.5 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 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 NW of ORB 17.3 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 W-15 5/3/2021 10.60 W-15 1/27/2020 10.87 NW of ORB 11.4 W-15 10/18/2021 11.13 W-15 4/25/2022 11.37 Page 33 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (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 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 Not considered - too far north 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 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 Not considered - outside PA 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 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 South of TB 13.7 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 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 West of TB 15.4 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 W-34 7/26/2021 17.73 South of TB 18.0 W-34 10/12/2020 17.76 W-34 10/18/2021 17.98 Page 34 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (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 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 West of TB 16.7 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 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 Not considered - too far SE 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 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 Not considered - too far NW 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 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 Not considered - too far NW 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 Page 35 BHI Energy ENG-OCS -013 BFM DCGLw/f Values: IU Exposure Pathways Rev. 1

Gen. Location Average Depth Well Date DTW (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 Aver. for wells near TB, RB, and All 13.89 ORB 14.5 fbg

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