ML17208A127
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN CHAPTER 6, REVISION 1 COMPLIANCE WITH THE RADIOLOGICAL CRITERIA FOR LICENSE TERMINATION
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 TABLE OF CONTENTS
- 6. COMPLIANCE WITH THE RADIOLOGICAL CRITERIA FOR LICENSE TERMINATION 6-1 6.1. Site Release Criteria ----------------------------------------------------------------------------- 6-1 6.2. General Site Description ------------------------------------------------------------------------ 6-1 6.2.1. Site Geology --------------------------------------------------------------------------------- 6-1 6.2.2. Site Hydrogeology -------------------------------------------------------------------------- 6-2 6.2.3. Area Land Use ------------------------------------------------------------------------------ 6-2 6.2.4. Area Groundwater Use--------------------------------------------------------------------- 6-2 6.3. Basements and Structures to Remain after License Termination (End State) ----------- 6-3 6.4. Dose Modeling Overview ---------------------------------------------------------------------- 6-5 6.4.1. Backfilled Basements ---------------------------------------------------------------------- 6-5 6.4.2. Soil -------------------------------------------------------------------------------------------- 6-7 6.4.3. Buried Piping -------------------------------------------------------------------------------- 6-7 6.4.4. Embedded Piping --------------------------------------------------------------------------- 6-8 6.4.5. Penetrations ---------------------------------------------------------------------------------- 6-8 6.4.6. Alternate Scenarios ------------------------------------------------------------------------- 6-9 6.5. Basement Fill Conceptual Model -------------------------------------------------------------- 6-9 6.5.1. Source Term --------------------------------------------------------------------------------- 6-9 6.5.2. Radionuclides of Concern --------------------------------------------------------------- 6-13 6.5.3. Critical Group and Exposure Scenario ------------------------------------------------ 6-21 6.5.4. Exposure Pathways ----------------------------------------------------------------------- 6-22 6.6. Basement Fill Computation Model ---------------------------------------------------------- 6-23 6.6.1. DUST-MS Model ------------------------------------------------------------------------- 6-23 6.6.2. Sensitivity Analysis ---------------------------------------------------------------------- 6-30 6.6.3. RESRAD Model -------------------------------------------------------------------------- 6-33 6.6.4. Uncertainty Analysis --------------------------------------------------------------------- 6-35 6.6.5. BFM RESRAD Parameter Set and Groundwater Exposure Factor Calculation- 6-38 6.6.6. BFM Groundwater Dose Factors ------------------------------------------------------- 6-39 6.6.7. BFM Drilling Spoils Dose Factors ----------------------------------------------------- 6-40 6.6.8. Basement Surface DCGLs--------------------------------------------------------------- 6-42 6.6.9. Basement Surface Area Factors and Elevated Measurement Comparison ------- 6-49 6.7. Alternate Exposure Scenarios for Backfilled Basements -------------------------------- 6-54 6.8. Soil Dose Assessment and DCGL ----------------------------------------------------------- 6-56 6.8.1. Soil Source Term ------------------------------------------------------------------------- 6-56 6.8.2. Soil Radionuclides of Concern, Insignificant Contributor Dose andSurrogate Ratio ------------------------------------------------- 6-57 6.8.3. Soil Exposure Scenario and Critical Group ------------------------------------------- 6-59 6.9. Soil Computation Model - RESRAD v7.0 ------------------------------------------------- 6-59 6.9.1. Parameter Selection ---------------------------------------------------------------------- 6-59 6.9.2. Uncertainty Analysis --------------------------------------------------------------------- 6-60 6.10. RESRAD Results and Soil DCGLs ------------------------------------------------------- 6-63 6.11. Soil Area Factors ---------------------------------------------------------------------------- 6-63 6.12. Buried Piping Dose Assessment and DCGL -------------------------------------------- 6-63 6.12.1. Buried Pipe Source Term and Radionuclides of Concern ---------------------- 6-64 6-i
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 6.12.2. Buried Pipe Exposure Scenario and Critical Group ----------------------------- 6-65 6.12.3. Buried Pipe RESRAD Model for Excavation Scenario ------------------------ 6-65 6.12.4. Buried Pipe RESRAD Model for Insitu Scenarios ------------------------------ 6-66 6.12.5. Buried Pipe Uncertainty Analysis ------------------------------------------------- 6-67 6.12.6. Buried Pipe RESRAD Results ----------------------------------------------------- 6-68 6.12.7. Buried Piping DCGL ---------------------------------------------------------------- 6-71 6.12.8. Adjustment for Dose from Insignificant Contributors -------------------------- 6-73 6.13. Embedded Piping DCGL ------------------------------------------------------------------- 6-74 6.14. Penetration DCGL --------------------------------------------------------------------------- 6-76 6.15. Existing Groundwater Dose ---------------------------------------------------------------- 6-78 6.16. Clean Concrete Fill -------------------------------------------------------------------------- 6-78 6.17. Demonstrating Compliance with Dose Criterion --------------------------------------- 6-79 6.17.1. Description of Terms in Equation 6-11 ------------------------------------------- 6-81 6.18. References ------------------------------------------------------------------------------------ 6-83 LIST OF TABLES Table 6-1 Basements and Below Ground Structures included in the ZNPS End State.......... 6-4 Table 6-2 Initial Suite of Potential Radionuclides for ZNPS and Radionuclide Mixture Based on Auxiliary and Containment Concrete................................................... 6-16 Table 6-3 IC Dose from Mixtures ........................................................................................ 6-18 Table 6-4 IC Dose from Individual Cores (Normalized) ..................................................... 6-19 Table 6-5 Zion Radionuclides of Concern for Containment and Auxiliary Basements. .... 6-20 Table 6-6 Radionuclide Ratios from Concrete Cores .......................................................... 6-21 Table 6-7 General Parameters for DUST-MS Modeling ..................................................... 6-26 Table 6-8 Distribution Coefficients for DUST-MS Modeling ............................................. 6-26 Table 6-9 Basement Mixing Volumes for DUST-MS Modeling ......................................... 6-27 Table 6-10 Summary of DUST-MS Source Term Release Rate Assumptions for the Zion Basements ............................................................................................................ 6-29 Table 6-11 Range of Diffusion Coefficients for Cement and Selected Values for Radionuclides of Concern (Reference 6-21)........................................................ 6-29 Table 6-12 Range of DUST-MS Parameters Varied in Sensitivity Analysis......................... 6-30 Table 6-13 Peak Groundwater Concentration Factors (pCi/L per mCi Total Inventory) ...... 6-32 Table 6-14 Peak Fill Material Concentration Factors (pCi/g per mCi Total Inventory) ........ 6-32 Table 6-15 BFM Uncertainty Analysis Results for Parameters with lPRCCl > 0.25 ............. 6-36 Table 6-16 BFM Deterministic Values for Sensitive Parameters from Table 6-12 that are Radionuclide Independent....................................................................... 6-37 Table 6-17 BFM Deterministic Values for Sensitive Parameters from Table 6-12 that are Radionuclide Dependent ...................................................................................... 6-37 Table 6-18 RESRAD Results and GW Exposure Factors for BFM model............................ 6-38 Table 6-19 BFM GW Dose Factors (mrem/yr per mCi Total Inventory) .............................. 6-39 Table 6-20 BFM Drilling Spoils Dose Factors (mrem/yr per mCi Total Inventory) ............. 6-42 Table 6-21 Basement Surface Areas (Walls and Floors) ....................................................... 6-45 Table 6-22 Surface Areas for Circulating Water Intake Pipe, Circulating Water Discharge Tunnel, Circulating Water Discharge Pipes and Buttress Pits/Tendon Tunnels . 6-46 6-ii
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Table 6-23 Adjusted Basement Surface Areas for DCGL Calculation .................................. 6-46 Table 6-24 Adjusted BFM Groundwater Scenario DCGLBS (Adjusted for IC Dose) ........... 6-47 Table 6-25 Adjusted BFM Drilling Spoils Scenario DCGLBS (Adjusted for IC Dose) ......... 6-47 Table 6-26 Adjusted Basement DCGLB (Adjusted for IC Dose)........................................... 6-48 Table 6-27 Floor Surface Areas for Class 1 Basements ................................................... 6-51 Table 6-28 Drilling Spoils Scenario Area Factors ........................................................... 6-51 Table 6-29 Large Scale Industrial Excavation Alternate Scenario Dose ............................... 6-55 Table 6-30 Soil ROC Mixture and IC Dose Percentage Using the Table 6-2 Best Estimate Mixture. ............................................................................................... 6-58 Table 6-31 Soil IC Dose and Dose Percentage using Soil Sample Results ........................... 6-58 Table 6-32 Distribution Coefficients for Surface and Subsurface Soil RESRAD Analysis .. 6-60 Table 6-33 Surface Soil DCGL Uncertainty Analysis Results for Parameters with lPRCCl >0.25 ............................................................................................... 6-61 Table 6-34 Selected Deterministic Values for Surface Soil DCGL Sensitive Parameters from Table 6-21 That Are Radionuclide Independent ...................... 6-61 Table 6-35 Deterministic Values for Surface Soil DCGL Sensitive Parameters from Table 6-21 that are Radionuclide Dependent .............................................. 6-61 Table 6-36 Subsurface Soil DCGL Uncertainty Analysis Results for Parameters with lPRCCl > 0.25 .............................................................................................. 6-62 Table 6-37 Selected Deterministic Values for Subsurface Soil DCGL Sensitive Parameters from Table 6-28 that are Radionuclide Independent......................... 6-62 Table 6-38 Deterministic Values for Subsurface Soil DCGL Sensitive Parameters from Table 6-28 that are Radionuclide Dependent....................................................... 6-62 Table 6-39 Adjusted Surface Soil and Subsurface Soil DCGLs (Adjusted for IC Dose) ..... 6-63 Table 6-40 Surface Soil Area Factors .................................................................................... 6-64 Table 6-41 Subsurface Soil Area Factors ............................................................................... 6-64 Table 6-42 RESRAD DSR Results for Buried Pipe Dose Assessment to Support DCGL Development ........................................................................................................ 6-68 Table 6-43 Maximum Summed RESRAD DSRs from Excavation and Insitu Scenarios .... 6-72 Table 6-44 Buried Piping DCGLs (Not Adjusted for IC Dose) ............................................. 6-73 Table 6-45 Adjusted Buried Pipe DCGLs (Adjusted for IC Dose) .................................. 6-73 Table 6-46 Embedded Pipe Survey Unit Surface Areas ....................................................... 6-74 Table 6-47 Embedded Pipe DCGLEP (Adjusted for Insignificant Contributor Dose) ........... 6-75 Table 6-48 Penetration Survey Unit Surface Areas ............................................................... 6-76 Table 6-49 Ratio of Instant Release Maximum to Diffusion Release Maximum for Auxiliary Basement ........................................................................................ 6-77 Table 6-50 Adjusted Penetration DCGLPN (adjusted for insignificant contributor dose) ...... 6-78 Table 6-51 Dose Assigned to Clean Concrete Fill ................................................................. 6-79 6-iii
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 LIST OF FIGURES Figure 6-1 Zion Nuclear Power Station Geographical Location ........................................... 6-86 Figure 6-2 Zion Nuclear Power Station Owner Controlled Area .......................................... 6-87 Figure 6-3 Zion Nuclear Power Station Security Restricted Area ........................................ 6-88 Figure 6-4 Backfilled Basement and Structures to Remain Below 588 Elevation .............. 6-89 Figure 6-5 Cross Section A-A of Basements/Structures Below ............................................ 6-90 Figure 6-6 Cross Section B-B of Basements/Structures Below 588 Elevation to Remain at License Termination .......................................................................... 6-91 Figure 6-7 Cross Section C-C of Basements/Structures Below 588 Elevation to Remain at License Termination .......................................................................... 6-92 Figure 6-8 Cross Section D-D of Basements/Structures Below 588.................................... 6-93 Figure 6-9 Visualization of BFM Conceptual Model ............................................................ 6-94 Figure 6-10 RESRAD Parameter Selection Flow Chart ......................................................... 6-95 ATTACHMENT 1 RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis.6-83 ATTACHMENT 2 RESRAD Input Parameters for ZSRP BFM..6-98 ATTACHMENT 3 RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil Sensitivity Analysis6-113 ATTACHMENT 4 RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL.6-124 6-iv
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1 LIST OF ACRONYMS AND ABBREVIATIONS 2 AF Area Factor 3 ALARA As Low As (is) Reasonable Achievable 4 AMSL Above Mean Sea Level 5 ANL Argonne National Laboratory 6 BFM Basement Fill Model 7 CRA Conestoga Rovers & Associates 8 DCGL Derived Concentration Guideline Level 9 DCF Dose Conversion Factor 10 DUST-MS Disposal Unit Source Term - Multiple Species 11 EPA Environmental Protection Agency 12 FGR Federal Guidance Report 13 FOV Field of View 14 FSS Final Status Survey 15 GW Groundwater 16 HSA Historical Site Assessment 17 HTD Hard-to-Detect 18 IC Insignificant Contributor 19 ISFSI Independent Spent Fuel Storage Installation 20 ISOCS In-Situ Object Counting System 21 LTP License Termination Plan 22 MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual 23 MARSAME Multi-Agency Radiation Survey and Assessment of Materials and Equipment 24 Manual 25 MDC Minimal Detectable Concentration 26 NRC The U.S. Nuclear Regulatory Commission 27 ODCM Off-site Dose Calculation Manual 28 PRCC Partial Rank Correlation Coefficient 29 RASS Remedial Action Support Surveys 30 REMP Radiological Environmental Monitoring Program 31 RESRAD RESidual RADioactive materials 32 ROC Radionuclides of Concern 33 SFP Spent Fuel Pool 34 STS Source Term Survey 35 TEDE Total Effective Dose Equivalent 36 WWTF Waste Water Treatment Facility 37 ZNPS Zion Nuclear Power Station 6-v
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 38 ZSRP Zion Station Restoration Project 6-vi
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 39 6. COMPLIANCE WITH THE RADIOLOGICAL CRITERIA FOR 40 LICENSE TERMINATION 41 6.1. Site Release Criteria 42 The site release criteria for the Zion Station Restoration Project (ZSRP) are the radiological 43 criteria for unrestricted release specified in Title 10, Section 20.1402, of the Code of Federal 44 Regulations (10 CFR 20.1402):
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- Dose Criterion: The residual radioactivity that is distinguishable from background radiation 46 results in a Total Effective Dose Equivalent (TEDE) to an average member of the critical 47 group that does not exceed 25 mrem/yr, including that from groundwater sources of drinking 48 water; and 49
- As Low As (is) Reasonable Achievable (ALARA) Criterion: The residual radioactivity has 50 been reduced to levels that are ALARA.
51 Chapter 4 describes the methods and results for demonstrating compliance with the ALARA 52 Criterion. This Chapter describes the methods for demonstrating compliance with the Dose 53 Criterion.
54 6.2. General Site Description 55 This section provides a general description of the geology and hydrogeology at the Zion Nuclear 56 Power Station (ZNPS) site. Land and groundwater use in the vicinity of site are also 57 summarized. A detailed site description is provided in ZionSolutions TSD 14-003, Conestoga 58 Rovers & Associates (CRA) Report: Conestoga Rovers & Associates (CRA) Report, Zion 59 Hydrogeologic Investigation Report (Reference 6-1).
60 The ZNPS is located in Northeast Illinois approximately 40 miles north of Chicago, Illinois, and 61 42 miles south of Milwaukee, Wisconsin. ZNPS is in the extreme eastern portion of the city of 62 Zion, (Lake County) Illinois, on the west shore of Lake Michigan approximately 6 miles NNE of 63 the center of the city of Waukegan, Illinois, and 8 miles south of the center of the city of 64 Kenosha, Wisconsin (see Figure 6-1). The ZNPS owner controlled area is shown in Figure 6-2, 65 with a more detailed view of the Security-Protected Area shown in Figure 6-3.
66 6.2.1. Site Geology 67 The Site is underlain by overburden deposits and a regionally extensive sequence of consolidated 68 sedimentary deposits. In descending order, the following overburden stratigraphic units have 69 been identified:
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- Upper sand unit (also known as the Shallow Aquifer): Dense to very dense granular soils 71 which range in gradation from very fine sand to fine to coarse sand and, which contains some 72 gravel and occasional cobbles and boulders. This unit includes both native and fill sand.
73 Depth ranges from the ground surface to an elevation of approximately 555 feet Above Mean 74 Sea Level (AMSL).
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- Upper silty clay unit: Hard silt, silty clay, clayey silt, and sandy silt which contain some sand 76 and gravel and occasional cobbles and boulders. Depth ranges from approximately 525 feet 77 to 555 feet AMSL.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 78
- Lower sand unit: Dense to very dense sands and silty sands which contain some gravel, 79 occasional cobbles and boulders, and layers of hard silty clay, clayey silt, and sandy silt.
80 Depth ranges from approximately 480 feet to 525 feet AMSL. This unit is discontinuous.
81 The lower unconsolidated sand unit layer overlies an upper bedrock layer. This upper bedrock 82 layer is the Niagara Dolomite, a consolidated layer of carbonaceous marine sediments laid down 83 in the Silurian Period. It is about 200 feet thick in the vicinity of ZNPS.
84 6.2.2. Site Hydrogeology 85 Two aquifer units are present in the overburden material, the upper sand unit and the lower sand 86 unit. These two units are separated by a silty clay unit and together they comprise the shallow 87 unconsolidated aquifer system. The silty clay unit (found under the upper sand unit) is 88 approximately 30 feet thick and extends approximately 15 feet below the deepest structural 89 feature at ZNPS. The silty clay unit acts as an aquitard and prevents vertical migration of 90 groundwater. Therefore the underlying regional Silurian dolomite bedrock aquifer should not be 91 in hydraulic communication with the upper sand unit at ZNPS.
92 6.2.3. Area Land Use 93 The ZNPS Facility is located on the shore of Lake Michigan, in the eastern portion of the City of 94 Zion, and adjacent to the Illinois Beach State Park.
95 The Illinois Beach State Park is located along the Lake Michigan shoreline and is divided into a 96 northern unit and a southern unit, with ZNPS situated between the two units. The Illinois Beach 97 State Park encompasses 4,160 acres and received approximately 2.75 million visitors in 1998.
98 The Park is considered a natural resource.
99 The land located to the west of ZNPS is generally undeveloped with a limited number of 100 industrial/commercial facilities present along Deborah Avenue. Residential areas and the City of 101 Zion downtown are located west of the Chicago & Northwestern Railroad, which is west of the 102 Facility. The 2010 census listed the population of Zion as 24,413, with a population density of 103 2,489 per square mile. Lake Michigan borders the Facility to the east.
104 6.2.4. Area Groundwater Use 105 The City of Zion provides municipal water to City residents and the surrounding area. The water 106 is obtained from Lake Michigan by means of an intake pipe located approximately 1 mile north 107 of the Site and extending 3,000 feet into the Lake. The City of Zion municipal code requires all 108 improved properties to be connected to the City's water supply. The code states that it is 109 unlawful for any person to construct, permit or maintain a private well or water supply system 110 within the City which uses groundwater as a potable water supply. There is an exception for 111 some existing wells constructed prior to March 2, 2004. Notwithstanding the fact that current 112 municipal code prohibits construction of residential wells, the conceptual model for dose 113 assessment of backfilled basements conservatively includes the installation of a water supply 114 well on the site (see 6.5.3).
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 115 6.3. Basements and Structures to Remain after License Termination (End State) 116 The End State is defined as the configuration of the remaining below ground buildings, 117 structures, piping and open land areas at the time of license termination.
118 The Lease Agreement between ZionSolutions and Exelon, Section 8.5 of Exhibit C, titled 119 Removal of Improvements; Site Restoration integral to the Zion Nuclear Power Station, 120 Units 1 and 2 Asset Sale Agreement (Reference 6-2) requires the demolition and removal of all 121 on-site buildings, structures, and components to a depth of at least three feet below grade 122 [designated as an elevation of 588 foot Above Mean Sea Level (AMSL)]. All contaminated 123 systems, components, piping, buildings and structures above 588 foot elevation will be removed 124 during decommissioning and disposed of as waste. The decommissioning approach for ZSRP 125 also calls for the beneficial reuse of concrete from building demolition as clean fill. Concrete 126 that meets the non-radiological definition of Clean Concrete Demolition Debris and where 127 radiological surveys demonstrate that the concrete meets the 10 CFR 20.1402 criteria for 128 unrestricted use is free of plant derived radionuclides above background will be used.
129 Radiological surveys will be performed in accordance with the guidance of NUREG-1575, 130 Supplement 1, Multi-Agency Radiation Survey and Assessment of Materials and Equipment 131 Manual (MARSAME) (Reference 6-3).
132 In both Containment basements (Unit 1 and Unit 2), all concrete will be removed from the inside 133 of the steel liner above 565 foot elevation leaving only the remaining exposed liner below the 134 588 foot elevation and the concrete in the area under the vessel including the In-Core Instrument 135 Shaft leading to the under vessel area (designated as the Under-Vessel area), and the structural 136 concrete outside of the liner. In the Auxiliary and Turbine Building basements, all internal walls 137 and floors will be removed, leaving only the reinforced concrete floors and outer walls of the 138 building structures. For the Fuel Handling Building, the only portion of the structure that will 139 remain is the lower 12 feet of the Spent Fuel Pool (SFP) below the 588 foot elevation and the 140 concrete structure of the Fuel Transfer Canals after the steel liners have been removed. There 141 are five four additional below ground structures that will remain, including the lower concrete 142 portions of the Waste Water Treatment Facility (WWTF), Crib House/Forebay, Main Steam 143 Tunnels, Circulating Water Intake Piping and Circulating Water Discharge Tunnels. The 144 basements and structures that will remain at license termination as part of the End State are listed 145 in Table 6-1. Figure 6-4 provides a simple plan view of the End State. A series of four cross-146 sections showing elevation views of the basements and structures to remain is provided in 147 Figures 6-5 to 6-8.
148 The End State will also include a range of buried pipeing, embedded pipeing and penetrations.
149 For the purpose of this License Termination Plan (LTP), buried pipeing is defined as pipe that 150 runs through that contained in soil, embedded pipeing is defined as pipe that runs that contained 151 within thevertically through a concrete wall or horizontally through a concrete of structure floors, 152 and a penetrations is are defined as a pipe (or remaining pipe sleeve or concrete if the pipe is 153 removed) that traverses a wall and is cut on both sides of the wallthe remaining portions of 154 piping (or pipe sleeves if the pipe is removed) in walls after removal of accessible piping from 155 the interiors of buildings (and exterior of buildings for some piping). The list of penetrations and 156 embedded pipe to remain is provided in ZionSolutions TSD 14-016, Description of Embedded 157 Piping, Penetrations and Buried Piping to Remain in Zion End State (Reference 6-3). The 6-3
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 158 current list of buried piping to remain is provided in ZionSolutions TSD 14-015, Buried Pipe 159 Dose Modeling & DCGLs (Reference 6-4). and Chapter 2, Table 2-27 of this LTP. The list 160 may be updated after the issuance of this LTP (Revision 10) based on engineering reviews or 161 changes in project plans, although significant revision is not expected.
162 163 Table 6-1 Basements and Below Ground Structures included in the ZNPS End State Lowest Internal Elevation Basement/Structure Material remaining (feet AMSL)
Unit 1 Containment Building Steel Liner over Concrete 568 Unit 2 Containment Building Steel Liner over Concrete 568 Auxiliary Building Concrete 542 Turbine Building Concrete 560 Crib House and Forebay Concrete 552 WWTF Concrete 577 Spent Fuel Pool Concrete 576 Main Steam Tunnels (Unit 1 and Concrete 570 Unit 2)
Circulating Water Intake Piping1 Steel Pipe in Concrete Trench (Site) 552/(Lake) 543 Circulating Water Discharge Concrete (Site) 552/(Lake) 543 Tunnels 164 Note 1: For the purposes of dose modeling the Service Water Headers are included with the Circulating Water 165 Intake Piping 166 There is limited potential for contaminated surface or subsurface soil to be present at ZNPS 167 based on the findings of the Zion Station Historical Site Assessment (HSA) (Reference 6-5) 168 and the results of extensive characterization performed in 2013. The results of the 169 characterization surveys are summarized in Chapter 2 of this LTP.
170 There has been no groundwater contamination identified by the groundwater monitoring 171 program at ZNPS. The monitoring program and results are described in the TSD 14-003. The 172 groundwater monitoring results are summarized in LTP Chapter 2, section 2.3.6.5.
173 After all demolition, remediation and backfill is completed, the 10 CFR Part 50 license will be 174 reduced to the area around the Independent Spent Fuel Storage Installation (ISFSI) and the site 175 will be transferred back to Exelon under the 10 CFR Part 50 license.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 176 6.4. Dose Modeling Overview 177 Dose modeling is performed to demonstrate that remaining residual radioactivity does not result 178 in a dose exceeding the 25 mrem/yr criterion. The Average Member of the Critical Group 179 (AMCG) is assumed to be the Resident Farmer. This section provides a general overview of the 180 dose modeling approach.
181 There are four five potential sources of residual radioactivity that are categorized as follows for 182 the purpose of dose modeling; backfilled basements, embedded piping and penetrations, buried 183 pipieng, soil, and groundwater. As noted above, there is no indication that significant 184 contamination is currently present in surface or subsurface soil or will be present in the End 185 State. The potential for groundwater contamination is also very low but groundwater dose 186 conversion factors are included as a contingency. The dose from each of the four five sources 187 will be summed as applicable.
188 The backfilled basement dose includes the dose from walls and floors, embedded pipe, and 189 penetrations in the applicable basement. The dose margin applied to clean concrete fill will also 190 be added to the applicable basement.
191 An overview of the dose assessment methods for the fivefour sources, and embedded pipe and 192 penetrations, is provided below. Detailed descriptions are provided in subsequent sections.
193 6.4.1. Backfilled Basements 194 The dose model for backfilled basements and structures to remain below 588 foot elevation at 195 ZNPS (which are generally referred to as Basements in this LTP Chapter) is designated as the 196 Basement Fill Model (BFM). The BFM calculates the annual dose to the AMCG from surface 197 and volumetric residual radioactivity remaining in the basement and structures listed in Table 198 6-1.
199 The End State Basements will be comprised of steel and/or concrete structures which will be 200 covered by at least three feet of clean soil and physically altered to a condition which would not 201 realistically allow the remaining structures, if excavated, to be occupied. The exposure pathways 202 in the BFM are associated with residual radioactivity in floors and walls that is released through 203 leaching into water contained in the interstitial spaces of the fill material. The BFM assumes that 204 the inventory of residual radioactivity in a given building is released either instantly or over time 205 by diffusion, depending on whether the activity is surficial or volumetric, respectively.
206 The activity released into the fill water will adsorb onto the clean fill, as a function of the 207 radionuclide-specific distribution coefficients, resulting in equilibrium concentrations between 208 the fill and the water. Consequently, the only potential exposure pathways after backfill, 209 assuming the as-left geometry, are associated with the residual radioactivity in the water 210 contained in the fill.
211 A water supply well is assumed to be installed within the fill of the Basement. The well water is 212 then used for drinking, garden irrigation, pasture/crop irrigation, and livestock water supply in 213 the Resident Farmer scenario.
214 The BFM is implemented using two computational models. The Disposal Unit Source Term -
215 Multiple Species (DUST-MS) model is used to calculate the maximum water concentrations in 6-5
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 216 the fill material of each basement for a given inventory of residual radioactivity (pCi/L per mCi).
217 The RESidual RADioactive materials (RESRAD) v7.0 model is used to determine the dose to 218 the Resident Farmer as a function of the water concentration (mrem/yr per pCi/L). BFM 219 Groundwater (GW) Dose Factors are then calculated for each Basement and each Radionuclide 220 of Concern (ROC) by combining the results of the two models with units of mrem/yr per mCi 221 total inventory.
222 The BFM also includes the dose from drilling spoils that are brought to the surface during the 223 well installation, which is assumed to be at the time of maximum projected future groundwater 224 concentrations. The drilling spoils are assumed to be comprised of fill material containing 225 residual radioactivity at the maximum equilibrium concentrations. Any activity remaining in the 226 concrete is also included in the drilling spoils source term. BFM Drilling Spoils Dose Factors 227 are also calculated in units of mrem/yr per mCi total inventory.
228 The final outputs of the BFM are the Basement Derived Concentration Guideline Levels 229 (DCGL)Dose Factors, in units of pCi/m2, which are calculated usingthe sum of the BFM GW 230 and BFM Drilling Spoils Dose Factors and have units of mrem/yr per mCi. DCGLs are 231 calculated separately for the GW and Drilling Spoils scenarios and for the summation of both 232 scenarios. The individual Basement Scenario DCGLs are defined as DCGLBS and represent a 233 dose of 25 mrem/yr for each scenario individually. The basement summation DCGL includes the 234 dose from both the GW and Drilling Spoils scenarios and represents a dose of 25 mrem/yr from 235 both scenarios combined. The summation DCGL is designated as the DCGLB and is used 236 during FSS to demonstrate compliance (equivalent to the DCGLW as defined in MARSSIM).
237 The Basement DCGLs Dose Factors are radionuclide-specific concentrationsvalues that 238 represent the 10 CFR 20.1402 dose criterion of 25 mrem/yr and are calculated for each ROC are 239 calculated separately for and each backfilled Basement. The final inventory of residual 240 radioactivity at the time of license termination will be multiplied by the Basement Dose Factors 241 to demonstrate compliance with the 25 mrem/yr dose criterion.
242 Basement Dose Factors DCGLs were calculated for each of the Basements listed in Table 6-1.
243 except for the Main Steam Tunnels (Unit 1 and Unit 2), Circulating Water Intake Piping and 244 Circulating Water Discharge Tunnels. TThe inventories in the Main Steam Tunnels and 245 Circulating Water Discharge Tunnels werewill be accounted for by adding adding the surface 246 area (and corresponding source term) to the inventories to the Turbine BuildingBasement during 247 the DCGL calculation (section 6.6.8). The inventory in the Circulating Water Intake Piping (and 248 Service Water Headers) was accounted for by adding the surface area to will be added to the 249 Crib House/Forebay Basement during the DCGL calculationsinventory. Therefore, the DCGLB 250 values calculated for the Turbine Basement also apply to the Circulating Water Discharge 251 Tunnels and the DCGLB values for the Crib House/Forebay also apply to the Circulating Water 252 Intake Piping. The Steam Tunnel surface area and volume were included with the Turbine 253 Basement in the calculation of BFM Dose Factors and DCGLs. The Turbine Basement DCGLs 254 therefore also apply to the Steam Tunnel. Note that there is expected to be minimal residual 255 radioactivity in the Steam Tunnels, Circulating Water Intake Piping (including Service Water 256 Headers) and Circulating Water Discharge Tunnels.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 257 6.4.2. Soil 258 Derived Concentration Guideline Levels (DCGLs) were developed for residual radioactivity in 259 surface and subsurface soil that represent the 10 CFR 20.1402 dose criterion of 25 mrem/yr. A 260 DCGL was calculated for each ROC.
261 Two soil DCGLs were calculated, surface soil and subsurface soil that are defined by the 262 assumed thickness of the soil column from the surface downward. Surface soil is defined as that 263 contained in a 0.15 m depth from the surface. Subsurface soil is defined as that contained in a 264 1 m depth of soil from the surface. These definitions apply to a continuous soil column from the 265 surface downward. There is no expectation of subsurface contamination in a geometry 266 comprised of a clean soil layer over a contaminated soil layer at depth.
267 The subsurface soil DCGL, which is based on a 1 m soil depth, can conservatively be applied to 268 any soil depth greater than 0.15 m and less than 1 m. In the unlikely event that geometries are 269 encountered during continuing characterization or during FSS that are not bounded by the 0.15 m 270 and 1 m soil thicknesses, the discovered geometries will be addressed by additional modeling.
271 The U.S. Nuclear Regulatory Commission (NRC) will be notified if additional modeling is 272 required.
273 Standard methods for RESRAD parameter selection and uncertainty analysis are used in 274 accordance with guidance in NUREG-1757, Volume 2, Revision 1 Consolidated 275 Decommissioning Guidance - Characterization, Survey, and Determination of Radiological 276 Criteria (Reference 6-6). The AMCG for soil is the Resident Farmer.
277 6.4.3. Buried Piping 278 Buried pipe is defined as pipe that runs through soil. The critical group for the buried piping dose 279 assessment is the Resident Farmer.
280 The buried pipe DCGLs, in units of dpm/100cm2, are determined for two scenarios; assuming 281 that all pipe is excavated and assuming that all pipe remains in situ. Although unrealistic, for the 282 purpose of the bounding modeling approach used, the dose from the two scenarios is summed to 283 determine the Buried Pipe DCGL. RESRAD was used to calculate DCGLs for both the 284 excavation and in situ buried pipe scenarios using the parameters developed for soil modified as 285 necessary for the buried pipe source term geometry. Details on dose assessment methods are 286 provide in section 6.12. A brief overview of scenario assumptions is provided below.
287 The excavation scenario assumes that all buried pipe is excavated after license termination and 288 all activity on the internal surfaces of the pipes is instantly released and mixed with surface soil.
289 The in situ scenario assumes that all of the buried piping remains in the as-left condition at the 290 time of license termination and that all activity is instantly released to adjacent soil. Two separate 291 in situ calculations were performed. The first calculation assumes that all pipes are located at 1 m 292 below the ground surface in the unsaturated zone and the second assumes that all pipes are 293 located in the saturated zone. The lowest in situ DCGL from either the 1m deep unsaturated or 294 saturated scenario was assigned as the in situ DCGL.The buried piping dose model assumes that 295 the pipe degrades over time and the entire inventory of residual radioactivity on the interior 296 surface of the pipe is released to a volume of soil equivalent to the interior volume of the pipe.
297 The soil is then assumed to be excavated as a part of basement construction for a house in the 6-7
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 298 Resident Farmer scenario, brought to the surface and spread over a surface area with a depth of 299 0.15 m. Based on the area over which the excavated soil is spread, the soil concentration 300 corresponding to 25 mrem/yr is calculated for each ROC using the calculated site-specific soil 301 DCGLs and Area Factors (AF). An initial buried piping DCGL is then calculated for the interior 302 surface of the pipes, in units of dpm/100 cm2, such that the total inventory on the pipe surfaces is 303 equal to the allowable inventory in the excavated soil volume. The buried piping dose model 304 also includes the dose contribution from the in situ buried piping which is determined using 305 RESRAD. The initial DCGLs based on excavation were lowered as an adjustment to account for 306 the in situ dose to generate the final buried piping DCGLs.
307 6.4.4. Embedded Piping and Penetrations 308 Embedded pipe is defined as pipe that runs vertically through concrete walls or horizontally 309 through concrete floors and is contained within a given building. There only release pathway for 310 the inventory of residual radioactivity in remaining End State embedded piping and penetrations 311 (which may only be comprised of sleeves for penetrations where the piping is removed) is into 312 the bBasement(s) where the piping is containedor penetrations terminate. The inventory in eThe 313 dose from embedded piping is summed with the dose from the wall and floor surfaces of the 314 basement that contains the embedded pipe (see section 6.12.9)and penetrations will be accounted 315 for by adding the inventory measured during the Final Radiation Survey (FRS) to the applicable 316 Basement inventory and including it in the BFM source term. To ensure conservatism, the 317 inventory in penetrations between Basements will be added to the Basement that has the highest 318 projected future water concentration. A DCGL, in units of pCi/m2, was calculated for each 319 embedded pipe survey unit. To eliminate the potential for activity in embedded pipe to result in 320 the release of radioactivity that could potentially result in higher concentrations than predicted by 321 the BFM, remediation and grouting action levels were established (see LTP Chapter 5, section 322 5.5.6). However, the dose from embedded pipe will be calculated using the DCGLs in order to 323 accurately account for the dose.
324 6.4.5. Penetrations 325 A penetration is defined as a remaining system pipe (or the metal sleeve if the system pipe is 326 removed, or concrete if the sleeve is removed or no sleeve was present) that runs through a 327 concrete wall and/or floor, between two buildings, and is open at the wall or floor surface of each 328 building. A penetration could also be a pipe that runs through a concrete wall and/or floor and 329 opens to a building on one end and the outside ground on the other end. The levels of residual 330 radioactivity in the majority of penetrations is expected to be low.
331 Penetrations are divided into separate survey units depending on which basements the 332 penetrations interface with. A DCGL, in units of pCi/m2, was calculated for each penetration 333 survey unit assuming that the residual radioactivity is released to both basements(s) that the 334 penetrations interface. The DCGL calculation conservatively assumes that 100% of the 335 penetration source term is simultaneously released to both basements.
336 To eliminate the potential for activity in penetrations to result in the release of radioactivity that 337 could potentially result in higher concentrations than predicted by the BFM, remediation and 338 grouting action levels have been established (see LTP Chapter 5, section 5.5.6). However, the 6-8
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 339 dose from penetrations will be assigned based on the calculated DCGLs in order to accurately 340 account for the dose.
341 The dose from penetrations is summed with the dose from the wall and floor surfaces of both 342 basements that the penetration interface (see section 6.12.9).
343 6.4.5.6.4.6. Alternate Scenarios 344 Several alternate scenarios for land use after backfill were qualitatively considered including 345 industrial use, recreational use (i.e., parkland), and residential use without a water supply well or 346 onsite garden. The Resident Farmer scenario, with onsite well is clearly a very conservative, 347 bounding scenario relative to the alternatives.
348 The BFM and the alternate scenarios considered above are based on the as left geometry of the 349 residual contamination in the backfilled Basements. Two additional low probability alternate 350 scenarios were considered that included changes to the as left backfilled geometry. The first 351 entails construction of a basement to the Resident Farmer house within the fill material. Note 352 that the assumed three meter depth of the basement excavation is insufficient to encounter fill 353 material potentially containing residual radioactivity (resulting from leaching of residual 354 radioactivity from surfaces after backfill) assuming the Basement is not constructed within the 355 saturated zone. However, a simple check of direct radiation dose to the resident was conducted 356 to confirm the expectation that the dose would be negligible.
357 The second alternate scenario that includes disturbance of the as-left geometry considers a very 358 unlikely assumption of a large-scale excavation of the backfilled structures after license 359 termination. The potential doses from large scale excavation were checked by averaging the 360 hypothetical maximum total activityinventory corresponding to 25 mrem/yr in the BFM over the 361 mass of the basement concrete and fill. The average concentrations were compared to the soil 362 concentrations equivalent to 25 mrem/yr based on an industrial use scenario which was assumed 363 to be the only future use that would justify large scale excavation of fill and concrete located 364 deep within the saturated zone.the soil DCGLs as a screening approach.
365 6.5. Basement Fill Conceptual Model 366 This section describes in detail the BFM conceptual model, including the source term, ROC, 367 future land use and exposure scenario, AMCG, and exposure pathways. The BFM is used to 368 calculate dose to the AMCG from residual radioactivity in the backfilled, below ground 369 Basements to remain at the time of license termination. The list of Basements to remain is 370 provided in Table 6-1. The computational model used to implement the conceptual model is 371 described in section 6.6.
372 6.5.1. Source Term 373 The source term for the BFM is the total inventory of residual radioactivity, surface plus 374 volumetric, remaining in each of the Basements at the time of license termination. The source 375 term includes residual radioactivity inventory in wall and floor concrete, or steel liner in the case 376 of the Containment Basements, as well as in embedded piping and penetrations that are 377 contained in or interface with a given basement. Embedded pipe and penetrations are treated as 378 separate survey units within the applicable basement that release activity into the basement fill in 6-9
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 379 the same manner as activity from walls and floors (see sections 6-13 and 6-14). The embedded 380 pipe and penetration source terms are accounted for by adding the dose from the embedded pipe 381 and penetration survey units to the dose from the applicable basement wall and floor survey unit.
382 The total dose from all three sources within a given basement must be less than 25 mrem/yr. See 383 section 6.17.1 for discussion of the process for summing the dose from walls/floors, embedded 384 pipe, and penetrations. is included in the applicable Basement inventories and the sum of both 385 the concrete (or steel liner in the case of the Containment Basements) and piping inventory is 386 used in the BFM dose assessment. The embedded piping and penetration source term is 387 discussed in section 6.12.
388 LTP Chapter 2 provides detailed characterization data regarding current contamination levels in 389 the Basements. The data is based on concrete core samples obtained at biased locations with 390 high contact dose rates and/or evidence of leaks/spills. The expected source term configuration 391 and radionuclide distribution expected to remain in each Basement, after remediation is 392 completed, is summarized below.
393 6.5.1.1. Unit 1 and Unit 2 Containment Building Basements 394 Both Unit 1 and Unit 2 Containment Buildings are comprised of concrete walls and floors with 395 all interior surfaces of the containment shell covered by a 0.25 inch steel liner. The liner on the 396 containment floor is at the 565 foot elevation floor and is covered by a 30 inch thick layer of 397 concrete. Consequently, the lower basement floor of each Containment Basement is currently at 398 the 568 foot elevation of the concrete. The Incore Tunnel floors of the Under-Vessel area under 399 the reactor vessels areis located at the 541 foot elevation. As with the 568 foot elevation 400 basement floor, a 30 inch layer of concrete is also present above the liner in the uUnder-vVessel 401 area and a 15 inch layer of concrete is on the walls in the Under-Vessel area. The steel liner on 402 walls above the 568 foot elevation and below the 588 foot elevation has surficial contamination 403 with removable contamination levels ranging from less than 1,000 dpm/100cm2 to approximately 404 10,000 dpm/100cm2 as indicated by operational and routine radiological surveys.
405 The concrete in the Uunder Vvessel areas is activated. The Bio-shield concrete surrounding the 406 vessel above 568 foot elevation is also activated. Core samples in the Incore Tunnels and from 407 the Unit 1 Bio-Shield indicate that the concrete was not activated through the entire depth. Core 408 samples from the Under-Vessel areas indicate low concentrations remain in activated concrete at 409 approximately 15 inches deep but activation through the entire depth is not expected. Continuing 410 Characterization of the Under-Vessel concrete is planned (see LTP Rev 1, Chapter 2, section 411 2.5).Therefore, Based on the results of cores to date, activation of the liner, or the concrete 412 outside of the liner, is not expected.
413 The source term for the Unit 1 and Unit 2 Containment Building Basement End States will be a 414 surface contamination layer distributed over the floor and wall surfaces of the remaining exposed 415 steel liner. All concrete inside of the liner, with the exception of the concrete in the Under-416 Vessel area, will be removed and disposed of as waste. Any remaining residual radioactivity on 417 the steel liner is anticipated to be the result of the deposition of airborne activity during 418 operations, commodity removal and during the removal of the contaminated interior concrete.
419 Dust suppression measures will be enacted during the removal process and settling of residual 420 radioactivity from airborne dust is expected to be minimal. In addition, operational 421 contamination control measures taken after concrete removal will include removal of loose 6-10
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 422 contamination as required for control of airborne radioactivity. As an illustration of the extent of 423 dust required to deposit on surfaces to be of even trivial consequence, a simple calculation was 424 performed. Based on a nominal estimate of the average radioactivity concentration, before 425 remediation, of 240 pCi/g in the containment concrete (contaminated and activated),
426 approximately 2 g of dust would be required over an area of 100 cm2 to produce surface 427 contamination levels that exceed 1,000 dpm/100cm2.
428 The analyses of concrete core samples from Containment Basements indicate that the majority of 429 the contamination is Cs-137. Ni-63, Co-60, Sr-90, Cs-134, H-3, Eu-152, and Eu-154 were also 430 detected but at significantly lower abundance (see section 6.5.2 for mixture fractions).
431 The current Containment Basement inventories are not meaningful as a prediction of End State 432 inventories because the vast majority of the contamination is in the concrete which will be 433 completely removed during decommissioning. However, the radionuclide mixtures from the core 434 data are considered reasonably representative of the End State mixture. In accordance with 435 ZionSolutions TSD 14-019, Radionuclides of Concern for Soil and Basement Fill Model Source 436 Terms (Reference 6-7) the nominal estimate of the inventory that will remain in the End State 437 of each Containment Basement is approximately 1.0E-04 Ci, assuming 1,000 dpm/100cm2 438 uniformly distributed over the entire interior surface of the remaining exposed liner surface. The 439 activity remaining in the Under Vessel area concrete will be determined through continuing 440 characterization.
441 6.5.1.2. Auxiliary Building Basement 442 The source term for the Auxiliary Building Basement End State is contamination in the 443 remaining concrete walls and floors. The Auxiliary Building has no steel liner.
444 The majority of the remaining End State inventory in the Auxiliary Building Basement will be 445 surface and volumetric contamination in the concrete floor and lower walls of the 542 foot 446 elevation. During the operation of ZNPS, the 542 foot elevation of the Auxiliary Building was 447 routinely flooded with contaminated water, resulting in the contamination of the concrete floor.
448 There are water marks on the lower walls up to approximately one meter high.
449 The upper walls above 545 foot elevation will also be contaminated but at significantly lower 450 concentrations than the floors. Upper wall contamination is expected to primarily be in the 451 vicinity of floors that will have been removed during demolition. Loose surface contamination 452 will also be present on remaining concrete surfaces due to the deposition of airborne 453 radioactivity generated during operations, commodity removal and the demolition of interior 454 concrete structures. The inventory attributable to surface contamination on walls has not been 455 estimated but is expected to be a small percentage of the total surface and volumetric inventory 456 in the 542 elevation floor and lower walls.
457 Characterization results indicate that current levels of loose contamination in the 542 elevation 458 floor range from <1,000 dpm/100 cm2 to over 250 mrad/swipe.
459 Fixed contamination is present at the surface and at depth in the concrete primarily at the 460 542 foot elevation floor. To illustrate the distribution and depth of contamination, a range of 461 core sample results from gamma spectroscopy analysis is provided here (see Chapter 2, section 462 2.3.3.2 for more details on core sample mean and distribution). Seventeen core samples were 6-11
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 463 collected from the 542 foot elevation floor. The highest concentrations were found in the first 464 0.5 inch where Co-60 concentrations averaged 46 pCi/g, with a maximum concentration of 465 456 pCi/g, and Cs-137 concentrations averaged 3,352 pCi/g with a maximum concentration of 466 25,100 pCi/g. The highest concentrations are expected to be limited to RHR Pump Rooms that 467 total approximately 20 m2. In some areas, the depth of contamination is greater than 0.5 inches.
468 For example, in the Unit 1 and Unit 2 Pipe Chase Rooms, Cs-137 concentrations of 530 pCi/g 469 and 1,650 pCi/g were observed at depths of 4 and 5 inches, respectively. Additional cores 470 identified a Cs-137 concentration of 57 pCi/g, at a depth of 2 inches in the central common area, 471 a Cs-137 concentration of 31 pCi/g at a depth of 3.5 inches in the east floor area, and a Cs-137 472 concentration of 63 pCi/g at a depth of 3 inches in the Unit 1 Equipment Drain Collection Tank 473 and Pump room.
474 The primary radionuclides by mixture percentage in the Auxiliary Building concrete are Cs-137 475 and Ni-63 (a non-gamma emitting radionuclide) at 75% and 242%, respectively. Cobalt-60, 476 Sr-90, and Cs-134 were also detected but at significantly lower percentages (see section 6.5.2 for 477 discussion of radionuclide mixture). Based on the results of the concrete core samples taken 478 during characterization, which were biased to the worst-case radiological conditions, the 479 current total inventory, including all radionuclides, in the Auxiliary Building is estimated to be 480 approximately 0.84 Ci (Reference 6-7). As discussed in section 6.6.9, minimum decontamination 481 level has been established to meet open air demolition limits as described in ZionSolutions 482 TSD 10-002, Technical Basis for Radiological Limits for Structure/Building Open Air 483 Demolition (Reference 6-8). Remediation to the open air limits will reduce the inventory.
484 6.5.1.3. Fuel Handling Building Basement and Transfer Canals 485 The only portion of the Fuel Handling Building Basement that will remain following building 486 demolition is the lower 12 feet (~4 m) of the SFP and Transfer Canals with floor elevations at 487 576 foot. The steel liner will be removed from both the SFP and the Transfer Canals. After the 488 liners are removed and the underlying concrete exposed, additional characterization surveys will 489 be performed to assess the radiological condition of the underlying concrete pad and remaining 490 pool walls. Contamination is expected below the liner but estimates of the range, distribution 491 and radionuclide mixture cannot be made until characterization is completed. The mixture is 492 expected to be similar to that found in contaminated concrete in the Auxiliary Building in that 493 the predominant radionuclide is expected to be Cs-137.
494 6.5.1.4. Turbine Building Basement and Steam Tunnels 495 Characterization surveys have shown that there is currently minimal residual contamination in 496 the structural surfaces of the Turbine Building. Analyses of concrete cores collected from the 497 floor of the Turbine Building at 560 foot elevation show the presence of Cs-137 at 498 concentrations greater than Minimal Detectable Concentration (MDC) at two of three sample 499 locations, and only in the first 0.5 inch of concrete. Cs-137 concentrations range from 0.6 pCi/g 500 to 47 pCi/g. In the Steam Tunnels, Cs-137 concentrations in the first 0.5 inch of concrete ranged 501 from 7 pCi/g to 47 pCi/g in Unit 1 and 0.3 pCi/g to 19 pCi/g in Unit 2. At depths greater than 502 0.5 inch, Cs-137 concentrations were below MDC. No other radionuclides were identified at 503 concentrations exceeding MDC. A nominal inventory estimate assuming 10% of the surface is 504 contaminated at the maximum concentration is 2E-05 Ci.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 505 6.5.1.5. Remaining Basements 506 Due to access restrictions, characterization was not performed in the remaining Basements, 507 including the Forebay, Circulating Water Intake Piping and Circulating Water Discharge 508 Tunnels. However, based on process knowledge and operational history, minimal or no 509 radioactive contamination is expected in these Basements. Concrete core samples were collected 510 from the Crib House as a part of concrete background studies. Only natural background activity 511 levels were detected.
512 513 The Circulating Water Discharge Tunnels were are the main authorized effluent release pathway 514 for the discharge of treated and filtered radioactive liquid effluent to Lake Michigan. During 515 plant operations and following shut-down, the liquid effluent release pathway was monitored and 516 the results presented in the annual Radiological Environmental Monitoring Program (REMP) 517 report in accordance with the Off-site Dose Calculation Manual (ODCM). The Unit 2 518 Circulating Water Discharge Tunnel was used as an authorized effluent release pathway during 519 decommissioning from 6/2013 to 10/2015.are still being used as an effluent pathway during 520 decommissioning which may result in additional contamination. The extent of this contamination 521 will be determined at the appropriate time during decommissioning The Circulating Water 522 Discharge Tunnels were surveyed as a part of continuing characterization program after effluent 523 release was discontinued (see LTP Chapter 2, section 2.5). or during Remedial Action Support 524 Surveys (RASS).
525 526 6.5.2. Radionuclides of Concern 527 NUREG-1757, section 3.3 states that radionuclides contributing no greater than 10% of the dose 528 criterion (i.e., 2.5 mrem/yr) are considered to be insignificant contributors (IC). This 10%
529 criterion applies to the sum of the dose contributions from the group of radionuclides considered 530 insignificant.
531 After the group of IC radionuclides insignificant contributors was identified and removed from 532 the initial suite of potential radionuclides, the IC dose from the insignificant contributors was 533 accounted for by adjusting the Basement DCGLsDose Factors for the remaining radionuclides 534 which are designated as the ROC (see section 6.6.8). The IC insignificant contributors 535 radionuclides are then excluded from further detailed evaluations. The remaining radionuclides 536 are designated as the ROC which are included in the source term for detailed dose modeling.
537 To identify the IC radionuclides insignificant contributors and develop the final ROC list, the 538 first step was to develop the initial suite of radionuclides that have a potential of being present.
539 6.5.2.1. Potential Radionuclides of Concern and Initial Suite 540 ZionSolutions TSD 11-001, Potential Radionuclides of Concern during the Decommissioning 541 of Zion Station (Reference 6-9) established the basis for an initial suite of potential ROC prior 542 to characterization. Three industry guidance documents were reviewed including 543 NUREG/CR-3474, Long-Lived Activation Products in Reactor Materials, (Reference 6-10),
544 NUREG/CR-4289, Residual Radionuclide Concentration Within and Around Commercial 6-13
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 545 Nuclear Power Plants; Origin, Distribution, Inventory, and Decommissioning Assessment 546 (Reference 6-11) and WINCO-1191, Radionuclides in United States Commercial Nuclear 547 Power Reactors (Reference 6-12). Radionuclide half-lives were obtained from ICRP 548 Publication 38, Radionuclide Transformations - Energy and Intensity of Emissions 549 (Reference 6-13). The review also included the evaluation of 19 post-shutdown waste streams.
550 Based on the elimination of noble gases, theoretical neutron activation products with an 551 abundance less than 0.01 percent relative to Co-60 and Ni-63 (the prominent activation products 552 identified in ZNPS samples), and radionuclides with half-lives less than two years, an initial suite 553 of radionuclides was selected that were considered to potentially be present during the 554 decommissioning of ZNPS.
555 After characterization at ZNPS was completed, the results of concrete core sample analyses 556 collected from the Containment Buildings and Auxiliary Building was reviewed in TSD 14-019.
557 Two radionuclides, Ag-108m and Eu-155 were positively identified in one or more 558 characterization cores and were therefore added to the list of potential radionuclides developed in 559 TSD 11-001. The resulting initial suite of potential radionuclides is provided in Table 6-2.
560 6.5.2.2. Radionuclide Mixture and Relative Dose Contribution for Initial Suite 561 Radionuclides 562 The mixture percentages for the initial suite of radionuclides for Containment and Auxiliary 563 Basement concrete were developed in TSD 14-019 using the results of the core sample analyses.
564 Several radionuclides in the initial suite were not positively identified in any of the core sample 565 analyses. The mixture percentages for these radionuclides were conservatively determined using 566 the reported MDC values. The mixture percentages for the initial suite are provided in 567 Table 6-2.
568 The mixture percentage fractions for the non-gamma emitters, or Hard-to-Detect (HTD) 569 radionuclides, were determined by analyzing selected cores from the Containment and Auxiliary 570 Basements that contained the highest radionuclide concentrations based on gamma spectroscopy.
571 The use of cores with higher concentrations was required to ensure that the percentage assigned 572 to HTD radionuclides were not overly influenced by the MDC values which was the only 573 concentration data available for the majority of the HTD radionuclides in the initial suite.
574 The radionuclide concentrations identified in core samples from the Turbine Building were very 575 low, which is consistent with expectations based on operational history. Given the very limited 576 data available, the direct determination of mixture percentages, particularly from the HTD 577 radionuclides, was not feasible. No characterization data was collected from the Forebay, 578 WWTF, and Circulating Water Intake Piping but the contamination levels, if any, in these 579 Basements are expected to be minimal. Concrete cores were collected in the Crib House as a part 580 of a background study and only natural background activity levels were identified.
581 Given the lack of available data and the very low levels of residual radioactivity expected to 582 remain, the radionuclide mixture for the Auxiliary Building was considered to be a reasonably 583 conservative mixture for the Turbine Basement, Crib House/Forebay, WWTF, and Circulating 584 Water Inlet Piping.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 585 The mixtures in the Circulating Water Discharge Tunnels and the SFP/Transfer Canals could be 586 somewhat different than the Auxiliary Building due to the sources of potential contamination, 587 i.e., effluent discharge during decommissioning and fuel pool water leaking into the concrete 588 under the liner, respectively. This will be evaluated as a part of the continuing characterization 589 process (see LTP Chapter 2, section 2.5).Access to the Circulating Water Discharge Tunnel was 590 not possible and therefore characterization data is unavailable. The discharge tunnel will be used 591 as the approved liquid effluent release pathway throughout decommissioning. As additional 592 radioactive material from different sources (i.e. processed SFP water) is introduced, this could 593 potentially result in a mixture that is different from the Auxiliary Building concrete mixture. The 594 mixture in the SFP/Transfer Canals could also be somewhat different than the Auxiliary Building 595 due to the source of potential contamination, i.e., fuel pool water leaking into the concrete under 596 the liner 597 The Auxiliary Basement mixture will be used for Source Term Survey (STS) planning and 598 implementation in these Basements.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 599 Table 6-2 Initial Suite of Potential Radionuclides for ZNPS and, Radionuclide Mixture 600 and Dose Contribution Based on Auxiliary and Containment Concrete Containment Auxiliary Nuclide Percent Percent Activity Activity H-3 0.074% 0.174%
C-14 0.008% 0.044%
Fe-55 0.174% 0.106%
Ni-59 0.156% 0.498%
Co-60 4.675% 0.908%
Ni-63 26.275% 23.480%
Sr-90 0.027% 0.051%
Nb-94 0.178% 0.013%
Tc-99 0.008% 0.016%
Ag-108m 0.282% 0.017%
Sb-125 0.025% 0.017%
Cs-134 0.008% 0.010%
Cs-137 67.582% 74.597%
Eu-152 0.436% 0.017%
Eu-154 0.058% 0.009%
Eu-155 0.018% 0.008%
Np-237 0.000% 0.0004%
Pu-238 0.001% 0.001%
Pu-239 0.000% 0.0005%
Pu-240 0.000% 0.001%
Pu-241 0.007% 0.028%
Am-241 0.007% 0.001%
Am-243 0.000% 0.001%
Cm-243 0.001% 0.0003%
Cm-244 0.001% 0.0003%
Total 100% 100%
601 6-16
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 602 However, the mixture in both the Circulating Water Discharge Tunnel and the SFP/Transfer 603 Canal is expected to be primarily Cs-137 as in the other Basements. Therefore, the Auxiliary 604 Basement mixture is considered reasonable for application to these two structures for planning 605 purposes. The mixtures in these two Basements will be reviewed as continued characterization 606 data is collected from these areas (see LTP Chapter 5, section 5.1).
607 Note that there is essentially no dose impact from uncertainty in the mixture fractions for beta-608 gamma emitting radionuclides because the FSS will be performed using gamma spectroscopy 609 and compliance with the 25 mrem/yr dose criterion will be demonstrated using actual measured 610 concentrations. The only potential dose impact of mixture uncertainty is therefore limited to the 611 HTD mixture percentages. The dose impact of HTD radionuclides in the BFM is very low as 612 demonstrated by the very low relative dose contribution of HTD radionuclides as discussed 613 below.
614 6.5.2.3. Insignificant Dose Contributors and Radionuclides of Concern 615 The relative and actual dose contributions from each radionuclide in the initial suite was 616 calculated to identify the IC radionuclidesinsignificant contributors and remove them from 617 further detailed consideration. The remaining radionuclides are designated as the ROC.
618 ZionSolutions TSD 14-010, RESRAD Dose Modeling for Basement Fill Model and Soil DCGL 619 and Calculation of Basement Fill Model Dose Factors and DCGLs (Reference 6-14) provides 620 DCGLB and DCGLBS values dose factorsfor the initial suite. Preliminary analyses indicated that 621 the ROC for the Auxiliary Basement were Cs-137, Co-60, Sr-90, Cs-134, and Ni-63. For 622 Containment, the preliminary ROC were the same five radionuclides with the addition of H-3, 623 Eu-152 and Eu-154.The BFM Dose Factors were calculated using the methods described in 624 section 6.6.
625 In TSD 14-019, the DCGLB and Drilling Spoils DCGLBS values for the initial suite radionuclides 626 dose factors were used to calculate the relative IC dose percentage and corresponding IC dose 627 (i.e., IC dose percentage times 25 mrem/yr) from the removed radionuclides. The IC dose for 628 Drilling Spoils was calculated separately because the Drilling Spoils DCGLBS is used directly in 629 the Elevated Measurement Comparison (EMC) test (see section 6.6.9). from each radionuclide 630 Five radionuclide mixturesgiven their respective mixture percentagess were assessed;. The 631 calculated dose percentage attributable to each radionuclide is provided in Table 6-2.
632
- mixture for Containment listed in Table 6-2 (which is considered the best estimate),
633
- mixture for Auxiliary Basement listed in Table 6-2 (which is considered the best 634 estimate),
635
- mixture using the 11 cores from Unit 1 Containment that were analyzed for the full initial 636 suite, 637
- mixture using the 10 cores from Unit 2 Containment that were analyzed for the full initial 638 suite, 639
- mixture using the 6 cores from the Auxiliary Basement that were analyzed for the full 640 initial suite.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 641 The IC dose was also calculated using the actual results (in units of pCi/g) from the individual 642 cores analyzed for the initial suite. The IC dose mean, standard deviation of the mean, and 95%
643 upper confidence level (UCL) were calculated for individual cores from Unit 1 Containment, 644 Unit 2 Containment and the Auxiliary Basement. The total dose and IC dose from the individual 645 cores were calculated assuming that the core concentrations were uniformly distributed over 646 100% of wall and floor surfaces of a given basement. In many cases, this hypothetical dose 647 exceeded 25 mrem/yr. The high dose was expected given that the cores were collected from 648 areas with the highest pre-remediation gamma activity. A concentration representing a dose 649 greater than 25 mrem/yr would require remediation. Therefore, the total dose, and corresponding 650 IC dose, for cores exceeding 25 mrem/yr were normalized to 25 mrem/yr to provide a value that 651 represents the percentage of the dose criterion to be consistent with the definition in NUREG-652 1757, section 3.3. The IC dose from a core with a total dose below 25 mrem/yr was reported 653 with no normalization.
654 The IC dose (normalized as applicable) was calculated for each core individually and the mean, 655 range, and 95% UCL compared to the IC dose calculated from the mixtures (i.e., dose 656 corresponding to the IC dose percentage times 25 mrem/yr). The individual core IC dose was 657 used to assess variability and inform the selection of the IC percentage assigned to adjust the 658 ROC DCGLs and to ensure the assigned percentage is sufficiently conservative. The results of 659 IC dose calculations based on mixtures are provide in Table 6-3. The IC dose from individual 660 cores is provided in Table 6-43.
661 Table 6-3 IC Dose from Mixtures Core Data IC Dose IC Dose Drilling Spoils mrem/yr mrem/yr (percent of (percent of 25 mrem/yr)4 25 mrem/yr)4 Table 6-2 Mixture Containment (Unit 1 and 0.13 0.06 2 Combined)
(0.51%) (0.15%)
(39 Cores - Initial Suite and Onsite Gamma)
Table 6-2 Mixture Auxiliary 0.33 0.01 (20 Cores - Initial Suite and Onsite Gamma) (1.31%) (0.22%)
Unit 1 Containment Mixture 0.13 0.08 (11 Initial Suite Cores) (0.51%) (0.33%)
Unit 2 Containment Mixture 0.07 0.05 (10 Initial Suite Cores) (0.28%) (0.22%)
Auxiliary Mixture 0.33 0.01 (6 Initial Suite Cores) (1.29%) (0.18%)
662 663 664 6-18
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 665 666 Table 6-4 IC Dose from Individual Cores (Normalized)
Core Individual Core IC Individual Individual Core Individual Population Dose Range Core IC Dose Core IC Dose 95% UCL Total Dose mrem/yr Mean Range(1)
(Percentage of 25 mrem/yr) mrem/yr mrem/yr mrem/yr Unit 1 0.06 to 2.01 Containment 0.37 0.66 2.18 to 2,212 (0.22% to 8.06%)
(11 cores)
Unit 2 0.02 to 1.03 Containment 0.30 0.48 0.99 to 3,228 (10 cores) (0.08% to 4.10%)
Auxiliary 0.27 to 0.73 0.53 0.63 6.48 to 76.42 (6 cores) (1.06% to 2.91%)
667 (1) Dose from all radionuclides before normalizing to 25 mrem/yr.
668 As seen in Table 6-3 and 6-4, the highest IC dose from the five mixtures evaluated was 0.33 669 mrem/yr (1.31%). The maximum individual core dose, was 2.01 mrem/yr (8.06%) and 0.63 670 mrem/yr (2.91%) for Containment and theAuxiliary Basement, respectively. The maximum 671 mean and 95% UCL for all individual core results were 0.53 mrem/yr and 0.66 mrem/yr, 672 respectively. From the review of the mean and 95% UCL values in Table 6-4, it is clear that the 673 maximum individual core IC dose of 2.01 mrem/yr (8.06%) is an outlier and not representative 674 of widespread conditions. The individual cores represent a range of contamination conditions, 675 with total dose projections (before normalization) from 0.99 mrem/yr to 3,228 mrem/yr, and are 676 considered representative of the range of conditions that that will be encountered during 677 decommissioning.
678 To account for any additional, unspecified variability and to provide confidence that HTD 679 analyses that may occur during continuing characterization will not result in an IC dose 680 exceeding that assigned to adjust the ROC DCGLs, a margin will be applied to the IC percentage 681 calculated using the Table 6-2 mixture by increasing the percentage to 5% for the Auxiliary 682 Basement and 10% for the Containment Basement (to account for the single core maximum of 683 8.06%). The resulting IC dose percentage of 5% and 10% (1.25 mrem/yr and 2.5 mrem/yr) will 684 be used to adjust the ROC DCGLs (Basement, Groundwater Scenario and Drilling Spoils 685 Scenario) for the Auxiliary Basement and Containment, respectively, to conservatively account 686 for the IC dose. These values exceed any mixture IC dose, individual core IC dose, or individual 687 core 95% UCL IC dose found in Tables 6-3 and 6-4 and is therefore considered a bounding 688 value.
689 The final ROC list for the Containment and the Auxiliary Basementuildings are provided in 690 Table 6-53. As discussed above, the Table 6-2 mixture is considered the most representative.
691 Therefore, the ROC and IC dose percentages in Table 6-5 are considered best estimates and are 692 provided for information and comparison to the selected IC percentage of 5% and 10% that will 693 be used to adjust DCGLs for the Auxiliary Basement and Containment, respectively. As shown 6-19
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 694 in Table 6-5, Tthe IC dose percentages for the Table 6-2 mixture attributable to the insignificant 695 contributors are that were removed from the initial suite is 0.51% and 1.321% for Containment 696 and Auxiliary Building, respectively, as seen in Table 6-3. The vast majority of dose is from Cs-697 137 at 97% (see Table 6-2). The next highest dose contributor was Co-60 at 1.7%. All 698 radionuclides, except Cs-137 could be included considered as insignificant contributors and 699 eliminated in accordance with the 10% criteriona. However, for conservatism and, in 700 anticipation of potential positive ISOCS results during FSSSTS, the low dose significant gamma 701 emitters Co-60 and Cs-134 are retained as ROC. Sr-90 and and Ni-63 are HTD radionuclides 702 that are low dose contributors in the Auxiliary Basement but do have some, albeit low, potential 703 for positive detection during FSS actually being present at levels above the MDC at the time of 704 license termination and are therefore also retained as ROC. The Containment ROC includes Eu-705 152, Eu-154 and H-3 because of their potential for being present in activated concrete, not due to 706 their dose contribution which is less than 0.1% total.
707 As discussed above, the Auxiliary Basement ROC and selected IC mixture percentage of 5% for 708 adjusting ROC DCGLs will also be applied to all other Basements with the possible exception of 709 the SFP/Transfer Canal and possibly the Circulating Water Discharge Tunnelsdepending on the 710 results of continuing characterization.
711 Table 6-56-3 Zion Radionuclides of Concern for Containment and 712 Auxiliary Basements.
Containment Auxiliary Radionuclide Percent Percent Percent Percent Activity Annual Dose2 Activity Annual Dose(2)
H-3(1) 0.074% 0.017% NA NA Co-60 4.675% 1.669% 0.908% 0.783%
Ni-63 26.275% 0.366% 23.480% 0.270%
Sr-90 0.027% 1.072% 0.051% 0.742%
Cs-134 0.008% 0.015% 0.010% 0.039%
Cs-137 67.582% 96.269% 74.597% 96.959%
Eu-152(1) 0.436% 0.067% NA NA Eu-154(1) 0.058% 0.010% NA NA Insignificant ContributorIC Dose Percentage (Table 6-2 Mixture) 0.864% 0.5124% 0.954% 1.313207%
Total 100% 100% 100% 100%
713 (1)Note 1: H-3, Eu-152 and Eu-154 are activation products and therefore applicable to Containment 714 Building only 6-20
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 715 716 (2) Percent annual dose and IC dose percentage based on best estimate mixture in Table 6-2 for 717 information. IC percentages of 5% and 10% will be used for ROC DCGL adjustment for Auxiliary and 718 Containment Basements, respectively, to provide additional margin.
719 720 6.5.2.4. Radionuclide Ratios for Application to Surrogate Approach 721 The FSS for basement surfaces will be performed using ISOCS gamma spectroscopy. Three 722 radionuclides that are not gamma emitters are included as ROC, i.e., Sr-90 and Ni-63 for the 723 Auxiliary Basement and Sr-90, Ni-63 and H-3 for Containment. As discussed in LTP Chapter 5, 724 the Sr-90, Ni-63 and H-3 concentrations will be accounted for using a surrogate approach during 725 FSS. The ratios of Sr-90/Cs-137, Ni-63/Co-60 and H-3/Cs-137 are required to implement the 726 surrogate approach.
727 The radionuclide ratios were calculated in TSD 14-019 by calculating the ratios of Sr-90/Cs-137, 728 Ni-63/Co-60 and H-3/Cs-137 within each individual core analyzed for the initial suite. Ratios 729 were calculated separately for Containment and the Auxiliary Basement. The mean, maximum, 730 and 95% UCL of the individual core ratios were calculated. The 95% UCL was conservatively 731 calculated using the standard deviation of the individual results as opposed to the standard 732 deviation of the mean. Table 6-6 provide the results. The maximum individual ratios are all 733 higher than the 95% UCL and will be used in the surrogate calculations during FSS.
734 Table 6-6 Radionuclide Ratios from Concrete Cores Radionuclide Containment Auxiliary Basement Ratio Mean Maximum 95% UCL Mean Maximum 95% UCL Sr-90/Cs-137 0.002 0.021 0.010 0.001 0.002 0.002 Ni-63/Co-60 30.62 442 194 44.14 180.45 154.63 H-3/Cs-137 0.21 1.76 0.96 NA NA NA 735 6.5.3.
736 6.5.4.6.5.3. Critical Group and Exposure Scenario 737 The critical group for the BFM dose assessment is the Resident Farmer. A well is assumed to be 738 installed onsite (in the center of the Basement with the highest projected future groundwater 739 concentrations), which supplies drinking water, water for livestock and irrigation water for a 740 garden and pasture/crop land. The Resident Farmer is considered a bounding exposure scenario 741 (as defined in NUREG-1757). A simple visualization of the BFM conceptual model is provided 742 in Figure 6-9.
743 The Reasonably Foreseeable Scenario, which is defined in NUREG-1757 as a land use 744 scenario that is likely within the next 100 years, could be justified as not including an onsite 745 water well which is prohibited by local municipal code (see section 6.2.4). Municipal water in 746 the vicinity of ZNPS is supplied by Lake Michigan, which is expected to be a viable source for 747 hundreds of years. In addition, Resident Farmer land use, with or without a well, would also be 748 unlikely for a minimum of 100 years after license termination considering current land use and 6-21
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 749 zoning in the area. Any type of residential use is essentially non-credible during the nominal 50 750 to 100 years while the ISFSI is expected to be present.
751 Current zoning at the ZNPS is heavy industrial use. The City of Zion, Official Zoning Map City 752 of Zion March 2011 (Reference 6-15) contains no agricultural use areas anywhere in the city.
753 In addition, a 2012 report by the United States Department of Agriculture, Custom Soil 754 Resources Report Lake County Illinois (Reference 6-16), classified the soil at ZNPS as 755 Category 3, which is defined as soils with severe limitations that reduce the choice of plants 756 or require special conservation practices, or both. While the zoning and soil classification may 757 not preclude a resident garden, the use of the land for raising livestock such as beef and dairy 758 cattle during the next 100 years could justifiably be categorized as a less likely but plausible 759 scenario (as defined in NUREG-1757, Table 5.1). Consistent with this definition, it would be 760 reasonable to not include livestock in the compliance dose assessment.
761 Using a simple assumption that the Resident Farmer well drilling scenario would not occur on 762 the site for at least the first 100 years after license termination, if at all, the BFM dose would be 763 reduced by about a factor of ten based on the radioactive decay of Cs-137, which is the 764 predominant radionuclide. Assuming that residential occupancy does occur after license 765 termination, eliminating the livestock pathway and retaining the onsite well, resident garden, 766 etc., would reduce the dose by approximately 60%. Notwithstanding all of the above, the BFM 767 applies the Resident Farmer land use to ensure that the critical group and exposure scenario 768 produce a conservative and bounding compliance dose calculation.
769 6.5.5.6.5.4. Exposure Pathways 770 The BFM applies to the backfilled Basements which will have a minimum of 3 feet cover and 771 approximately 3 m of clean fill above the potential source term zone as defined by the 772 equilibrium water level in the backfilled Basements. The equilibrium water level is 773 conservatively assumed to be at the natural water table elevation of 579 foot. Therefore, the dose 774 from the water-independent exposure pathways is negligible. Nonetheless, all Resident Farmer 775 exposure pathways, water-dependent and water-independent are included in the model to verify 776 this assumption. The aquatic pathway from an onsite pond is not credible due to engineering and 777 cost issues of construction and proximity to Lake Michigan which negates any foreseeable need 778 (TSD 14-003).
779 The Resident Farmer Scenario includes the following exposure pathways:
780
- Direct exposure to external radiation 781
- Inhalation dose from airborne radioactivity 782
- Ingestion dose from the following pathways; 783 - Plants grown with irrigation water from onsite well, 784 - Meat and Milk from livestock consuming fodder from fields irrigated with onsite well 785 water and consuming water from onsite well, 786 - Drinking water from onsite well, 787 - Soil ingestion.
6-22
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 788
- Direct exposure, inhalation dose and ingestion dose from contaminated drilling spoils 789 brought to the surface during installation of the onsite well into the fill material.
790 The last bullet is not a standard Resident Farmer exposure pathway as described in 791 NUREG/CR-5512, Volume 1, Residual Radioactive Contamination from Decommissioning 792 Parameter Analysis (Reference 6-17) or as contained in RESRAD. However, the BFM 793 Resident Farmer scenario is predicated on the well being installed into the basement fill which 794 will generate drilling spoils. Assuming a well is drilled, exposure to the spoils that are brought 795 to the surface is a potential exposure pathway. The potential dose contribution from this 796 pathway was checked in screening assessments and found to be greater than 10% of the total 797 BFM dose in some cases (see section 6.6.7). Therefore, the pathway was included in the BFM.
798 The well water dependent BFM exposure pathways are not applicable to the SFP due to the 799 elevation of the SFP floor being at the 576 foot elevation (see Table 6-1), which is only three feet 800 below the water table elevation of 579 foot. Operating water well in an area with only three feet 801 of available water is considered a land use that because of physical limitations could not occur 802 and is therefore implausible as defined in Table 5.1 of NUREG-1757. However, this would not 803 preclude a well driller from inadvertently picking a location above the SFP as a potential well 804 location and then rejecting the location based on low water level. Therefore, for the 805 SFP/Transfer Canal Basement, the pathways resulting from well water are not applicable, but the 806 drilling spoils pathway is applicable and will be applied in the BFM assessment. However, the 807 potential contribution of the SFP/ inventory to a well water pathway will be considered by 808 adding the SFP/Transfer Canal surface area to inventory to the Containment and Auxiliary 809 Basement surface areas during the DCGL calculation (see section 6.6.8). Adding the surface area 810 to the DCGL calculation corresponds to adding the inventory. This addition is necessary because 811 Tthe SFP/Transfer Canal will be hydraulically connected to the Containment Basements through 812 the Fuel Transfer Tubes and to the Auxiliary Basement through the opening in the wall between 813 the Transfer Canal and the Auxiliary Basement that was created to facilitate 814 decommissioning.perforations cut between the SFP and the Transfer Canals for the purpose of 815 equilibrating the SFP water levels with the other Basements.
816 The same argument regarding implausibility of well operation that was applied to the 817 SFP/Transfer Canal could also be applied to the WWTF, which has a floor that is only two feet 818 below the site groundwater levels and an internal Basement volume of 144 m3. However, the 819 WWTF is an isolated structure with no connections to other Basements and therefore, the 820 inventory cannot credibly be added to other Basements to conservatively account for the well 821 water exposure pathways. Therefore, the water well pathways are applied in the BFM for the 822 WWTF as a simple, bounding approach.
823 6.6. Basement Fill Computation Model 824 6.6.1. DUST-MS Model 825 The initial environmental transport pathway for the Resident Farmer scenario is the release of 826 radioactivity from Basement concrete (or steel liner surfaces for Containment Basements) to 827 water in the interstitial space of the fill material. The water concentrations in the Basements are 828 calculated using the DUST-MS computer code. The methods and results are summarized here 829 and described in detail in ZionSolutions TSD 14-009, Brookhaven National Laboratory Report 6-23
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 830 (BNL), Evaluation of Maximum Radionuclide Groundwater Concentrations for Basement Fill 831 Model, Zion Station Restoration Project (Reference 6-18). The water concentrations calculated 832 by DUST-MS were used in conjunction with RESRAD modeling results (see section 6.6.3) to 833 calculate BFM Dose Factors (see section 6.6.8).
834 The DUST code was originally developed through support from the NRC in 1992. Subsequent 835 development of the code led to the multiple species (MS) version. DUST-MS was used by the 836 NRC to develop guidance on performance assessment for low-level waste disposal and has been 837 accepted for use in LTPs for other power reactor sites.
838 To calculate the maximum water concentrations, the rate of radionuclide release from concrete 839 the source term to the fill is required. Diffusion controlled release is assumed for Basements 840 with volumetric contamination (i.e., Auxiliary and SFP/Transfer Canal) and instant release is 841 assumed for the remaining Basements where contamination is predominantly on or near the 842 structure surfaces.
843 After release, the residual radioactivity is assumed to mix instantly with the water the Basements.
844 The concentrations are calculated for each Basement independently. The only mechanism to 845 reduce the water concentration is sorption onto the fill material. The water concentration for this 846 model can be calculated using Equation 6-1.
847 Equation 6-1 848 = [ x ( + )]
849 where:
850 C = concentration in water (pCi/L) 851 I = inventory (pCi) 852 V = Basement mixing volume (L) 853 = effective porosity 854 = bulk density (g/cm3) 855 Kd = distribution coefficient (cm3/g) 856 Although simple spreadsheet calculations can be performed to determine equilibrium water 857 concentrations for the Basements with instant release, DUST-MS is used to simulate diffusion 858 controlled release for Basements with volumetrically contaminated concrete. In addition, a 859 sensitivity analysis was conducted of the impact of alternate well placement on groundwater 860 concentrations, assuming transport to a well located outside of the Basements (as opposed to the 861 being placed in the Basement fill) which also requires the use of DUST-MS. Therefore, all 862 calculations have been performed with DUST-MS to maintain consistency and for ease of 863 calculation and reporting 864 The water concentrations are calculated separately for each Basement with no assumption of 865 mixing between buildings. This is conservative given that there will be several open 866 penetrations between the Basements after piping is removed that will provide hydraulic 867 connectivity between the Basements. ZionSolutions TSD 14-032, Conestoga Rovers &
868 Associates Report, Simulation of the Post-Demoltion Saturation of Foundation Fill Using a 869 Foundation Water Flow Model (Reference 6-19) describes the remaining penetrations and the 870 projected equilibrium water levels in the Basements. Mixing and flow of water between 6-24
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 871 Basements will occur, primarily between the Auxiliary, Containment and Turbine Basements.
872 The maximum equilibrium water concentrations are conservatively calculated for the worst case 873 individual Basement (expected to be the Auxiliary Basement) assuming no mixing.
874 Based on current demolition plans, there will be no connection between the Basements and 875 surrounding groundwater. A number of pipes that penetrate the Turbine Basement walls and 876 enter the outside ground will be removed from both sides of the Basement walls or remain in the 877 ground outside of the Turbine basement. This will leave a number of penetrations open to the 878 outside ground, primarily on the east side of the Turbine Basement. However, none of these 879 open penetrations are below the water table (579 foot elevation). The Circulating Water 880 Discharge Tunnel (a large 14 foot wide concrete tunnel below 579 foot elevation) and the There 881 are two 48 inch diameter Service Water Supply Lines that run from the 549 foot elevation in the 882 are connected to the Turbine Building and Auxiliary Building, respectively, and to the ground 883 east of the Turbine Basement which will be cut at the 579 foot elevation in the ground.a depth 884 below the 579 foot elevation at some distance from the Basements. However, this piping and 885 will be filled with grout. or otherwise plugged. There are also a number of small diameter buried 886 pipes that penetrate Basements below the 579 foot elevation, primarily in the Auxiliary 887 Basement. These are designated as Building to Ground Penetrations, Buried Pipe in TSD 14-888 016. Most of these pipes are currently planned to be cut in the ground above the 579 foot 889 elevation and therefore above the average groundwater elevation. A few are listed as terminating 890 in the ground below 579 foot elevation. To eliminate uncertainty regarding water ingress or 891 egress through these small diameter penetrations that are connected to buried pipe, all of the 892 penetrations in this category that enter a basement below 579 foot elevation will be grouted 893 regardless of what elevation the buried pipe is cut within the ground. Grouting provides 894 additional assurance that Therefore, the End State configuration provides no route for 895 groundwater ingress into the Basements, leaving only rainwater infiltration as the source of water 896 in the fill.
897 TSD 14-032 estimated that it will take approximately 28 years to reach an equilibrium water 898 level across all Basements, considering rainwater infiltration rates and existing penetrations 899 between Basements. The DUST-MS model assumes that the Basements are full of water 900 immediately after license termination and capable of supporting a residential well, which is a 901 conservative assumption.
902 6.6.1.1. Parameter Selection 903 For DUST-MS modeling, the initial source term in each Basement is nominally assumed to be 904 1 pCi/m2 uniform activity over all walls and floor surfaces below 588 foot elevation. The 905 inventory corresponding to this activity (1 pCi/m2 multiplied by the surface area in a given 906 Basement) is the value used for the equilibrium calculations. However, it is important to note 907 that the value of the assumed inventory in each Basement is immaterial because the DUST-MS 908 modeling results are used to generate unitized Groundwater Concentration Factors in units of 909 pCi/L per mCi. The DUST-MS results will be used in conjunction with the RESRAD results 910 (see section 6.6.3) and scaled to the to calculate BFM Dose Factors in units of mrem/yr per mCi.
911 The BFM Dose Factors are then used to calculated DCGLs, in units pCi/m2 (see section 6.6.8).
912 actual inventory in each Basement at the time of license termination to calculate the annual dose 913 to the Resident Farmer.
6-25
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 914 The equilibrium calculation for released activity is simple as shown in Equation 6-1 and includes 915 limited input parameters. The selected model parameters are listed in Tables 6-74 and 6-85.
916 Table 6-76-4 General Parameters for DUST-MS Modeling Parameter Selected Value Kd Table 6-5 (Nuclide Dependent)
Porosity 0.25 Bulk Density 1.5 g/cm3 Basement Mixing Volume Table 6-6 (Basement Dependent) 917 Table 6-86-5 Distribution Coefficients for DUST-MS Modeling Radionuclide Basement Fill Kd (cm3/g)
Co-60 223 Ni-63 62 Sr-90 2.3 Cs-134 45 Cs-137 45 Eu-152 95 Eu-154 95 918 The specific composition of the backfill has not yet been determined but is expected to be some 919 combination of sand and debris resulting from building demolition that is designated for 920 beneficial reuse as clean hard fill. The demolition debris will consist of concrete and cinderblock 921 that has been demonstrated to be free of plant derived radionuclides using the MARSAME 922 process. The ratios of sand and demolition debris are not known and therefore, the bulk density 923 and porosity not known with certainty. ZionSolutions TSD 14-006, a report by Conestoga 924 Rovers & Associates, Evaluation of Hydrological Parameters in Support of Dose Modeling for 925 the Zion Restoration Project, (Reference 6-20) calculates site-specific values for the porosity 926 and density of local soil. The results were 0.35 and 1.8 g/cm3, respectively. Inspection of 927 Equation 6-1 shows that calculated water concentrations are inversely proportional to porosity 928 and density. Therefore, a conservative bulk density of 1.5 g/cm3 and porosity of 0.25 were 929 selected for the DUST-MS parameters. With any of the fill materials, it is unlikely that packing 930 of the material would result in porosity below 0.25.
931 The distribution coefficients (Kd) are important parameters in the calculation of equilibrium 932 concentrations. As shown in Equation 6-1, water concentration varies inversely with Kd.
933 Consequently, lower Kd values will result in higher projected future water concentrations.
934 ZionSolutions TSD 14-004, a report by Brookhaven National Laboratory, Recommended 935 Values for the Distribution Coefficient (Kd) to be used in Dose Assessments for Decommissioning 936 the Zion Nuclear Power Plant, (Reference 6-21) reviewed Kd values from three sources:
937 Data Sources for selection of DUST-MS Modeling distribution coefficients:
938
- literature values, 939
- site-specific Kd analyses performed by Brookhaven National Laboratory as documented in 940 two reports, ZionSolutions TSD 14-017, Sorption (Kd) Measurements on Cinder Block and 941 Grout in Support of Dose Assessments for Zion Nuclear Station Decommissioning 6-26
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 942 (Reference 6-22), and ZionSolutions TSD 14-020, Sorption (Kd) measurements in Support 943 of Dose Assessments for Zion Nuclear Station Decommissioning (Reference 6-23), and 944
- the 25th percentile values of the Kd distributions provided in NUREG/CR-6697, 945 Development of Probabilistic RESRAD 6.0 and RESRAD-BUILD 3.0 Computer Codes 946 (Reference 6-24).
947 In selecting values from literature, environmental conditions with high pH (cement sorption data) 948 as well as typical environmental soil sorption data were considered due to the anticipated 949 presence of concrete and cinderblock demolition debris in the fill. For conservatism the 950 minimum values from all of these sources were selected. For nuclides with measured site-951 specific Kd values, the lowest measured Kd in any potential backfill material or soil was selected.
952 6.6.1.2. Mixing Volume 953 The water concentrations calculated by DUST-MS are inversely proportional to the assumed 954 mixing volume which differs for each Basement as a function of the building geometry and 955 distance from the floor to the assumed water elevation in the Basements. Section 6.5.1 describes 956 the source terms and remaining structural configuration of the Basements.
957 The projected equilibrium water elevation in the Basements was evaluated in TSD 14-032. The 958 water level is driven by the location, elevation and size of existing penetrations between the 959 Basements and between the Basements and outside ground. The current decommissioning 960 approach does not include making additional perforations through Basement walls other than 961 between the SFP and the Transfer Canals. Given these conditions, the equilibrium water level in 962 the Basements was projected to be at the 586 foot elevation. A number of options are presented 963 in TSD 14-032 for perforating the basements to keep water levels at approximately 579 foot 964 elevation. ZSRP has selected Scenario 3 from TSD 14-032 which entails breaching the western 965 most portion of the north foundation wall of the Unit 2 Steam Tunnel. The breach will be 15-feet 966 wide and extend from the top of the foundation wall after demolition (588 AMSL) to an 967 elevation of 580 feet AMSL (i.e., one foot above the exterior water table). is currently evaluating 968 the potential benefit of perforating the Basement walls to reduce this equilibrium water level to 969 be essentially equivalent to the 579 foot elevation of surrounding groundwater. Regardless of 970 the extent and effect of possible added perforations, the water level in the Basements could not 971 be less than the elevation of the surrounding groundwater. To accommodate any future 972 perforation plans, and ensure conservatism, the mixing volume for the DUST-MS modeling is 973 based on a Basement water elevation equal to the 579 foot elevation of surrounding groundwater.
974 The resulting mixing volumes for each Basement are provided in Table 6-96.
975 Table 6-9 Basement Mixing Volumes for DUST-MS Modeling Basement/Structure Volume (m3)
Unit 1 Containment Building 6.54E+03 Unit 2 Containment Building 6.54E+03 Auxiliary Building 2.84E+04 Turbine Building 2.61E+04 6-27
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Crib House and Forebay 3.05E+04 WWTF 1.44E+02 Spent Fuel Pool and Transfer 2.08E+02 Canal Main Steam Tunnels NA - Volume included with Turbine (Unit 1 and Unit 2) Building volume of 2.61E+04 m3Inventory included with Turbine Building Circulating Water Intake Piping NA - Source term included with Crib House/Forebay and Turbine in DCGL calculation Inventory included wih Crib House and Forebay Circulating Water Discharge NA - Source term included with Turbine Tunnels Building in DCGL calculation Inventory included with Turbine Building 976 6.6.1.3. Radionuclide Release Rate 977 The release rate is a function of the source term geometry. In all of the Basements with the 978 exception of the Auxiliary Basement and possibly the SFP/Transfer Canal, the contamination is 979 expected to be surficial. This surface contamination may be relatively loosely bound. In these 980 Basements, the release is conservatively assumed to occur instantly such that the entire inventory 981 is available immediately after license termination. Activated concrete will remain in the Under-982 Vessel area of Containment. The assumption of instant release for Containment is very 983 conservative for activated concrete which would actually release radionuclides very slowly. If 984 deemed necessary as decommissioning proceeds, a separate calculation of the radionuclide 985 release rate from activated concrete may be performed to adjust the DCGL applicable to activity 986 as depth in activated concrete. If such a calculation is performed it will be documented in a TSD 987 and submitted to NRC for review.
988 The contamination in the Auxiliary Basement, and possibly the SFP/Transfer Canal, has diffused 989 into the concrete resulting in volumetric contamination. The Auxiliary Building has been 990 characterized and shown to be contaminated to a depth of at least the first inch of the concrete 991 and deeper in several locations. Leak detection tests have indicated that the steel liner of the SFP 992 does leak, but the extent of the concrete contamination under the liner is not known at this time.
993 After the liner has been removed, the underlying concrete of the SFP/Transfer Canal will be 994 characterized. Due to the volumetric source term, the release of contamination from Auxiliary 995 and SFP/Transfer Canal concrete, and the resulting maximum water concentrations, will be a 996 driven by time-dependent diffusion controlled release. For these two Basements, a diffusion 997 controlled release model is used. If contamination in the SFP/Transfer Canal is found to be 998 surficial, then the DUST-MS model will be rerun using an instant release rate. Table 6-10 7 999 summarizes the release rate assumptions used in DUST-MS modeling for each Basement.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1000 Table 6-106-7 Summary of DUST-MS Source Term Release Rate Assumptions 1001 for the Zion Basements Basement Release Rate Assumption Unit 1 Containment Instant ReleaseRelease (1) (loose surface contamination on steel liner)
Unit 2 Containment Instant ReleaseRelease (1) (loose surface contamination on steel liner)
Auxiliary Diffusion Controlled Release (concrete contamination at depth in concrete)
Turbine Instant Release (limited contamination present at concrete surface with very limited contamination at depth)
Crib House and Instant Release (limited or no surface contamination)
Forebay WWTF Instant Release (limited or no surface contamination)
SFP and Transfer Diffusion Controlled Release (Concrete contamination at depth expected Canals under liner) 1002 (1) A small volume of activated concrete will remain in the Under-Vessel areas of both Containments. The instant 1003 release assumption is very conservative for activated concrete.
1004 Diffusion coefficients for each ROC are required to estimate the rate of release from concrete in 1005 addition to the parameters listed in Tables 6-4 and 6-5. The diffusion coefficients from concrete 1006 will depend on the water to cement ratio used in forming the concrete and the aggregate.
1007 Table 6-811 lists a typical range of diffusion coefficients for concrete and provides reference(s) 1008 for the values. The water concentrations are proportional to the diffusion coefficient, so the 1009 maximum value in the range was selected for use in the DUST-MS modeling.
1010 The diffusion rate also depends on the contamination depth profile. The majority of the 1011 contamination in Auxiliary Basement is found in the first one inch of concrete. However, there 1012 are some locations where the contamination is deeper. The diffusion modeling in DUST-MS 1013 conservatively assumes that the contamination is 0.5 inch deep. All activity in the concrete, 1014 including any activity deeper than 0.5 inch, will be determined during the FSSSTS (see LTP 1015 Chapter 5, section 5.5). and included in the assessment of total inventory. All activity deeper 1016 than 0.5 inch will be assumed to be included in the first 0.5 inch. This is a conservative approach 1017 because the deeper contamination would diffuse out more slowly. In addition, assuming that the 1018 Table 6-116-8 Range of Diffusion Coefficients for Cement and Selected Values 1019 for Radionuclides of Concern (Reference 6-21)
Nuclide Diffusion Coefficient Selected Diffusion Range (cm2/s) Coefficient (cm2/s)
H-3 6.0E 5.5E-07 5.5E-07 Co-60 5.0E 4.1E-11 4.1E-11 Ni-63 8.7E 1.1E-09 1.1E-09 6-29
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Sr-90 1.0E 5.2E-10 5.2E-10 Cs-134; Cs-137 4.0E 3.0E-09 3.0E-09 Eu-152; Eu-154 1.0E 5.0E-11 5.0E-11 1020 total inventory is within the first 0.5 inch of concrete will increase the effective concentration in 1021 the first 0.5 inch. This assumption will increase the diffusion rate which is driven by the 1022 concentration gradient.
1023 The depth of contamination for DUST-MS diffusion modeling of the concrete in the 1024 SFP/Transfer Canal is also assumed to be 0.5 inch. The depth of contamination in the 1025 SFP/Transfer Canal concrete is not known at this time and will be characterized after the liner is 1026 removed. If contamination is found at depths significantly greater than 0.5 inch, then the model 1027 may be re-run using the actual depth profile. This re-run would be at the discretion of ZSRP if it 1028 were determined that the 0.5 inch thickness assumption was too conservative. In this case, the 1029 results would be made available for NRC review. All other DUST-MS parameters would remain 1030 the same.
1031 6.6.2. Sensitivity Analysis 1032 Although conservative parameters were selected for DUST-MS as described above, a sensitivity 1033 analysis was performed for Kd, porosity, and density to ensure that further parameter review was 1034 not necessary. A simple assessment was performed by varying each parameter independently 1035 through range of +/- 25% of the selected parameter as shown in Table 6-12.
1036 Table 6-126-9 Range of DUST-MS Parameters Varied in Sensitivity Analysis Parameter Selected Value Sensitivity Range Kd Table 6-5 (Nuclide Dependent) +/- 25% of Value in Table 6-5 Porosity 0.25 0.19 - 0.31 Bulk Density 1.5 g/cm3 1.1 - 1.8 g/cm3 1037 1038 The results show minimal impact in varying the parameters through the range as listed below.
1039 No adjustment of the conservatively selected parameter values is deemed necessary.
1040
- Kd: An increase in Kd caused a decrease in solution concentration and a slight increase in 1041 sorbed concentration on fill. Solution concentration is approximately inversely proportional 1042 to Kd. The 25% change in Kd had a minimal impact on the amount sorbed or the backfill 1043 concentration (pCi/g). Sr-90 showed the largest percentage change in sorbed concentration 1044 of all the nuclides but it was less than 2.5%.
1045
- Porosity: Changing porosity had a minor impact on the amount sorbed and solution 1046 concentration. The amount of radioactivity in solution was proportional to the porosity (but 1047 the concentration was lower). This reflects the increased volume of water available for 1048 mixing in higher porosity media and corresponding higher total amount of activity in the 1049 water.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1050
- Density: The solution concentration, sorbed concentration and amount in solution are 1051 inversely proportional to density. Increasing density causes a decrease in solution 1052 concentration. The change in density has a minor impact (< 2%) on the total amount of 1053 radioactivity that is sorbed.
1054 The sensitivity of the depth of contamination in the diffusion release model was also assessed.
1055 As expected, the maximum water concentrations decreased with an increased depth of 1056 contamination. Therefore, a minimum concrete contamination depth of 0.5 inches was used in 1057 the DUST-MS modeling.
1058 6.6.2.1. Sensitivity of Well Placement 1059 The placement of the well inside the Basement(s) is unlikely because it is assumed that the driller 1060 will recognize that the spoils are not natural materials and, that the high pH of the water inside 1061 the Basement(s) due to the presence of concrete and cinderblock demolition debris will make the 1062 water unsuitable for domestic use. In addition, encountering construction debris during drilling 1063 and meeting refusal at the Basement floor will further discourage the use of a well drilled into 1064 the Basements. However, the BFM conservatively assumes that the well is placed inside of the 1065 Basement(s). A simple assessment was performed in TSD 14-009 to determine the potential 1066 effect of well placement outside of the walls of the Basement(s) to illustrate that the well 1067 placement assumption was conservative.
1068 For the well placement sensitivity assessment, the well was assumed to be located in the shallow 1069 sand aquifer at the closest location downstream of the Basement(s) to the east of the Turbine 1070 Building. In this assessment, the Auxiliary Building is modeled with contamination released in 1071 this building flowing through the Turbine Building similar to the physical layout at the site. The 1072 initial inventory in the Turbine Building was reduced by a factor of 0.001 consistent with the 1073 much higher measured concentrations in the concrete of the Auxiliary Building. Water flow 1074 through the system is assumed to be at the local groundwater velocity (e.g., the Basement walls 1075 are assumed to be transparent and allow free flow of groundwater). The results indicate that the 1076 water concentration (and corresponding Resident Farmer dose) would be reduced by 1077 approximately two orders of magnitude for Cs-137 if the well were located outside of the 1078 Basements at the nearest downstream location. The reduction for Co-60 is much greater. The 1079 Sr-90 concentrations are only slightly reduced due to the very low assumed Kd of 2.3 cm3/g.
1080 This analysis further supports the conclusion that the BFM conceptual model, which assumes 1081 that the well is placed inside a Basement, is bounding.
1082 6.6.2.2. DUST-MS Model Results 1083 Tables 6-130 and 6-141 (Reference 6-18) provide the results of the DUST-MS calculations for 1084 each Basement and ROC. The tables report the maximum Groundwater Concentration Factors 1085 (pCi/L per mCi) and corresponding Fill Concentration Factors (pCi/g per mCi). Note that both 1086 of these values occur at the same point in time.
1087 The maximum concentrations occur at the time of license termination for the Basements with 1088 instant source term release. The time of maximum concentrations varies for each ROC in the 1089 Auxiliary Building Basement and SFP/Transfer Canal as a function of half-life and diffusion 6-31
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1090 coefficient. For application in the BFM, the maximum concentration factors are used and 1091 conservatively assumed to occur at one point in time for all radionuclides.
1092 Table 6-136-10 Peak Groundwater Concentration Factors (pCi/L per mCi Total 1093 Inventory)
Crib House Auxiliary Containment Turbine Fuel WWTF Nuclide /Forebay (pCi/L/mCi) (pCi/L/mCi) (pCi/L/mCi) (pCi/L/mCi) (pCi/L/mCi)
(pCi/L/mCi)
Co-60 4.00E-03 4.57E-01 1.14E-01 5.45E-01 9.77E-02 2.08E+01 Cs-134 1.06E-01 2.26E+00 5.65E-01 1.45E+01 4.83E-01 1.03E+02 Cs-137 3.80E-01 2.26E+00 5.65E-01 5.22E+01 4.83E-01 1.03E+02 Eu-152 1.65E-02 1.07E+00 2.68E-01 2.24E+00 2.29E-01 4.83E+01 Eu-154 1.29E-02 1.07E+00 2.68E-01 1.76E+00 2.29E-01 4.83E+01 H-3 1.40E+02 6.13E+02 1.53E+02 1.91E+04 1.31E+02 2.78E+04 Ni-63 2.92E-01 1.64E+00 4.10E-01 4.01E+01 3.52E-01 7.47E+01 Sr-90 3.01E+00 4.13E+01 1.04E+01 4.12E+02 8.85E+00 1.89E+03 1094 1095 1096 Table 6-146-11 Peak Fill Material Concentration Factors (pCi/g per mCi Total 1097 Inventory)
Crib House Auxiliary Containment Turbine Fuel WWTF Nuclide /Forebay (pCi/g/mCi) (pCi/g/mCi) (pCi/g/mCi) (pCi/g/mCi) (pCi/g/mCi)
(pCi/g/mCi)
Co-60 8.92E-04 1.02E-01 2.55E-02 1.22E-01 2.18E-02 4.64E+00 Cs-134 4.77E-03 1.01E-01 2.54E-02 6.53E-01 2.18E-02 4.63E+00 Cs-137 1.71E-02 1.01E-01 2.54E-02 2.35E+00 2.18E-02 4.63E+00 Eu-152 1.58E-03 1.02E-01 2.55E-02 2.15E-01 2.18E-02 4.64E+00 Eu-154 1.22E-03 1.02E-01 2.55E-02 1.67E-01 2.18E-02 4.64E+00 H-3 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 Ni-63 1.81E-02 1.02E-01 2.54E-02 2.49E+00 2.18E-02 4.64E+00 Sr-90 6.94E-03 9.50E-02 2.38E-02 9.46E-01 2.03E-02 4.33E+00 1098 The Groundwater Concentration Factors are used in conjunction with Groundwater Exposure 1099 Factors generated by RESRAD to develop the BFM GW Dose Factors which are one of the 1100 inputs to the that will be used DCGL calculations in section 6.6.8. in the final dose assessment to 1101 demonstrate that the residual radioactivity in the Basements complies with the 25 mrem/yr Dose 1102 Criterion 6-32
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1103 6.6.3. RESRAD Model 1104 The RESRADv7.0 computer code was used to calculate the Resident Farmer dose from a unit 1105 radionuclide concentration in the well water. A Groundwater Exposure Factor, in units of 1106 mrem/y per pCi/L was generated for each ROC. As discussed in section 6.6.8, tThe 1107 Groundwater Exposure Factors are combined with the Groundwater Concentration Factors 1108 generated using DUST-MS to calculate the BFM GW Dose Factors for each ROC in units of 1109 mrem/y per mCi. total inventory.
1110 6.6.3.1. Parameter Selection 1111 RESRAD parameters are classified as behavioral, metabolic or physical. Some parameters may 1112 belong to more than one category. The parameter classification is documented in 1113 NUREG/CR-6697. Physical parameters are determined by the source, its location, and 1114 geological characteristics of the site (i.e., these parameters are source- and site-specific) 1115 including the geohydrologic, geochemical, and meteorologic characteristics of the site. The 1116 characteristics of atmospheric and biospheric transport up to, but not including, uptake by, or 1117 exposure of, the dose receptor would also be considered physical input parameters.
1118 Behavioral parameters define the receptors behavior considering the conceptual model selected 1119 for the site. For the same group of receptors, a parameter value could change if the scenario 1120 changed (e.g., parameters for recreational use could be different from those for residential use).
1121 For the ZNPS, the behavioral parameters are based on a Resident Farmer scenario and are the 1122 same for both the BFM and soil dose assessments.
1123 Metabolic parameters define certain physiological characteristics of the potential receptor. One 1124 set of metabolic parameters applies to both the BFM and soil dose assessments. Physical, 1125 behavioral and metabolic parameters are treated as deterministic parameters in the final dose 1126 modeling to calculate Groundwater Exposure Factors. The deterministic module of the code 1127 uses single values for input parameters and generates a single value for dose. The parameter 1128 selection process is described below.
1129 Argonne National Laboratory (ANL) ranked physical parameters by priority as 1, 2, or 3.
1130 Priority 1 parameters have the highest potential impact on dose and Priority 3 the least. This 1131 ranking is documented in Attachment B to NUREG/CR-6697.
1132 Priority 3 physical parameters were assigned the median values from the parameter distributions 1133 defined in NUREG/CR-6697. Priority 1 and 2 parameters were evaluated by uncertainty 1134 analysis using the NUREG/CR-6697 parameter distributions. The Partial Rank Correlation 1135 Coefficient (PRCC) was used to evaluate the relative sensitivity of the Priority 1 and 2 1136 parameters. A PRCC value less than -0.25 was considered sensitive and negatively correlated to 1137 dose. The 25th percentile of the NUREG/CR-6697 distribution was assigned to negatively 1138 correlated parameters. A PRCC value greater than 0.25 was considered sensitive and positively 1139 correlated to dose. The 75th percentile of the distribution from NUREG/CR-6697 was assigned 1140 to positively correlated parameters. Priority 1 and 2 parameters with a lPRCCl less than 0.25 1141 were assigned the median value of the NUREG/CR-6697 parameters.
1142 Consistent with the guidance in NUREG-1757, section I.6.4.2, metabolic and behavioral 1143 parameters were assigned the mean values from NUREG/CR-5512 Vol. 3, Residual 6-33
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1144 Radioactive Contamination From Decommissioning Parameter Analysis Table 6.87 1145 (Reference 6-25).
1146 Figure 6-10 provides a flow chart of the parameter selection process.
1147 The RESRAD code contains several Dose Conversion Factor (DCF) libraries that can be selected 1148 by the user. The DCF library selected for the BFM applies inhalation and ingestion DCFs from 1149 the Environmental Protection Agency (EPA) Federal Guidance Report (FGR) No. 11, Limiting 1150 Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for 1151 Inhalation, Submersion and Ingestion (Reference 6-26) and direct external exposure dose 1152 conversion factors from FGR No. 12 External Exposure to Radionuclides in Air, Water and 1153 Soil (Reference 6-27).
1154 There are four RESRAD parameters that were assigned values that are specific to the BFM as 1155 listed below:
1156
- Time since material placement = 1 year 1157
- Mass Balance Groundwater Model 1158
- 100% of the initial contamination in the water table 1159
- No unsaturated zone (unsaturated zone depth = 0) 1160 The parameter value for time since material placement of one year was selected for user 1161 convenience to allow RESRAD to calculate an equilibrium well water concentration at run time 1162 equal to zero for all radionuclides. The assumption that 100% of the initial contamination is in 1163 the water table, no unsaturated zone and Mass Balance Groundwater Model removes the time 1164 dependence of travel through an unsaturated zone in the reported well water concentrations as a 1165 function of time. All radionuclides achieve maximum well water concentrations at t=0.
1166 However, none of these parameters effect the calculation of the Groundwater Exposure Factors 1167 (mrem/y per pCi/L), which can be calculated for any year and any well water concentration since 1168 they are unitized. The relationship between dose and well water concentration is independent of 1169 time or water concentration.
1170 In a similar manner, the saturated zone and contaminated zone hydrogeological parameters have 1171 no impact on the calculation of the unitized Groundwater Exposure Factors for the BFM.
1172 However, instead of using the default values for these parameters they were selected and 1173 justified using the full process shown in Figure 6-10. This was done for two reasons, to allow 1174 the same parameter set to be used for the site specific soil DCGL determination in section 6.9 1175 (with slight modification) and to eliminate any potential concerns that the hydrogeological 1176 parameters could impact the dose calculations due to unforeseen effects on the RESRAD 1177 calculations.
1178 Finally, the RESRAD model was run deterministically, i.e., single values were selected for all 1179 parameters. In practice, this only affects the few Priority 1 and 2 physical parameters that are not 1180 site-specific or sensitive, which would be run with the distributions from NUREG/CR-6697 in a 1181 probabilistic approach as opposed to the mean values.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1182 6.6.4. Uncertainty Analysis 1183 Uncertainty analysis was performed to ensure that conservative values are selected for 1184 parameters that have a relatively high correlation to dose. Attachment 1 provides the input 1185 parameter set used to perform the uncertainty analysis. The parameter selection process is 1186 discussed below.
1187 For the uncertainty analysis, deterministic parameters are selected for behavioral, metabolic and 1188 Priority 3 physical parameters in accordance with the process in Figure 6-10. The majority of 1189 the Priority 1 and 2 physical parameters are assigned the parameter distributions from 1190 NUREG/CR-6697. Three site-specific Priority 1 and 2 physical parameters were assigned 1191 deterministic values in the uncertainty analysis including cover depth, precipitation, well 1192 pumping rate (which does not have a recommended distribution in NUREG/CR-6697). In 1193 addition, as discussed in section 6.6.1.1, the Kd values were assigned conservative deterministic 1194 values based on the review of various literature sources and site-specific data documented in 1195 TSD 14-004. The assigned Kd values apply to the basement fill material and are therefore the 1196 same as selected for the DUST-MS model (see Table 6-5). There are other site-specific 1197 deterministic parameters available, but these are included in the uncertainty analysis by applying 1198 the parameter distributions from NUREG/CR-6697 to ensure the appropriate level of 1199 justification is provided if one or more of these parameters were determined to be sensitive.
1200 The uncertainty analysis was conservatively run for all ROC individually to maximize the 1201 parameter sensitivity. A more realistic approach would be to only apply the radionuclide 1202 mixture fractions found at ZNPS. Using the ZNPS fractions could reduce the sensitivity of total 1203 dose to some parameters for the low abundance radionuclides. In addition, parameter input rank 1204 correlations were not applied in order to maximize variability and corresponding parameter 1205 sensitivity. The RESRAD Uncertainty Reports are provided in TSD 14-010. Table 6-15 1206 provides the parameters with lPRCCl values greater than 0.25 and the reported PRCC values.
1207 The PRCC values listed are the highest individual values from the three runs made in the 1208 RESRAD Uncertainty Analysis. Table 6-16 and Table 6-17 list the selected 75th or 25th 1209 percentile deterministic values from the NUREG/CR-6697 distributions for the sensitive 1210 parameters (i.e., those listed in Table 6-15).
1211 The values in Tables 6-16 and 6-17 were used in the RESRAD modeling to determine the 1212 Groundwater Exposure Factors. The median of the distributions from NUREG/CR-6697 were 1213 assigned to Priority 1 and 2 parameters that were not sensitive (i.e., not listed in Table 6-15).
1214 6-35
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1215 Table 6-156-12 BFM Uncertainty Analysis Results for Parameters with lPRCCl > 0.25 PRCC Value Parameter Co-60 Cs-134 Cs-137 Eu-152 Eu-154 Ni-63 Sr-90 H-3 Depth of Roots 0.33 NS1 NS NS NS NS NS NS Weathering Removal Constant of All -0.61 -0.88 -0.87 -0.87 -0.89 -0.78 -0.80 NS Vegetation Wet Weight Crop Yield of Fruit Grain and Non- NS NS NS -0.51 -0.54 NS NS NS Leafy Vegetables Wet Foliar Interception Fraction of Leafy NS NS NS 0.56 0.59 NS NS NS Vegetables Plant Transfer Factor NS NS NS NS NS NS 0.31 NS Meat Transfer Factor 0.90 0.86 0.85 0.75 0.77 0.32 0.59 NA Milk Transfer Factor 0.56 0.91 0.90 NS NS 0.97 0.68 NA Saturated Zone NS NS NS NS NS NS -0.36 -0.54 Hydraulic Conductivity Saturated Zone NS NS NS NS NS NS -0.59 -0.77 Hydraulic Gradient Contaminated Zone NS NS NS NS NS NS -0.41 -0.77 Total Porosity Density of NS NS NS NS NS NS 0.41 0.73 Contaminated Zone 1216 Note 1: NS indicates that the parameter is not sensitive 1217 1218 1219 6-36
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1220 Table 6-166-13 BFM Deterministic Values for Sensitive Parameters from 1221 Table 6-12 that are Radionuclide Independent Parameter Percentile Parameter Value Depth of Roots 75th 3.1m Weathering Removal Constant of All Vegetation 25th 21.5 Wet Weight Crop Yield of Fruit Grain and Non-25th 1.26 kg/m2 Leafy Vegetables Wet Foliar Interception Fraction of Leafy 75th 0.70 Vegetables Saturated Zone Hydraulic Conductivity 25th 1695 Saturated Zone Hydraulic Gradient 25th 0.0018 Contaminated Zone Total Porosity 25th 0.37 Density of Contaminated Zone 75 th 1.681 g/cm3 1222 Note 1: Site specific density value of 1.8 used in the RESRAD run.
1223 Table 6-176-14 BFM Deterministic Values for Sensitive Parameters from 1224 Table 6-12 that are Radionuclide Dependent Plant Transfer Meat Transfer Milk Transfer Radionuclide Factor Factor Factor 75th Percentile 75th Percentile 75th Percentile Co-60 NS1 0.058 0.0032 Cs-134 NS 0.065 0.014 Cs-137 NS 0.065 0.014 Eu-152 NS 0.004 NS Eu-154 NS 0.004 NS Ni-63 NS 0.0092 0.032 Sr-90 0.59 0.013 0.0028 H-3 NS NS NS 1225 Note 1: NS indicates that the parameter is not sensitive 1226 The density of the contaminated zone was identified as sensitive and positively correlated. As 1227 noted in Table 6-16, the 75th Percentile of the NUREG/CR-6697 Attachment C distribution is 1228 1.68 g/cm3. However, the site-specific density value for sand is 1.8 g/cm3 (TSD 14-006).
1229 Because the fill will be a combination of concrete and sand, and concrete density is 2.4 g/cm3, 1230 the 1.8 g/cm3 for sand is the minimum site-specific value and was therefore applied.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1231 6.6.5. BFM RESRAD Parameter Set and Groundwater Exposure Factor 1232 Calculation 1233 The final RESRAD parameter set used to calculate the Groundwater (GW) Exposure Factors is 1234 provided in Attachment 2. The RESRAD BFM Summary Report and Concentration Report are 1235 provided in TSD 14-010.
1236 A few of the parameters required simple calculations, which are described in the Attachment 2 1237 parameter table. A calculation was also performed to develop a nominal value of 2250 m3 for 1238 the well pumping rate parameter including drinking water, livestock consumption and irrigation 1239 in the Resident Farmer Scenario. This calculation is provided at the end of Attachment 2.
1240 The GW Exposure Factors are calculated by dividing the maximum dose, which occurs at t=0 in 1241 the RESRAD simulations for all ROC, by the well water concentration at t=0 as shown in 1242 Equation 6-2. The RESRAD results for each ROC and the calculated GW Exposure Factors are 1243 provided in Table 6-185.
1244 Equation 6-2 1245 () = ()/ ()
1246 where:
1247 GW Exposure Factor (i) = Dose from unitized groundwater concentration 1248 (mrem/y per pCi/L) 1249 Total Dose (i) = Total dose from radionuclide (i) calculated by RESRAD 1250 (mrem/yr) 1251 GW Concentration (i) = Groundwater concentration for radionuclide (i) calculated 1252 by RESRAD (pCi/L) 1253 1254 Table 6-186-15 RESRAD Results and GW Exposure Factors for BFM model Dose (mrem/y) GW Exposure Groundwater Factor Radionuclide Drinking Plant/Meat/ Concentration Total (mrem/y per Water Milk (pCi/L) pCi/L)
Co-60 5.40E-02 5.82E-02 1.12E-01 4.48E+00 2.50E-02 Cs-134 6.58E-01 1.28E+00 1.94E+00 2.21E+01 8.75E-02 Cs-137 5.23E-01 1.01E+00 1.54E+00 2.21E+01 6.94E-02 Eu-152 3.17E-02 6.30E-03 3.80E-02 1.05E+01 3.62E-03 Eu-154 4.61E-02 9.14E-03 5.52E-02 1.05E+01 5.26E-03 H-3 1.38E-01 7.88E-02 2.17E-01 4.89E+03 4.43E-05 Ni-63 4.42E-03 1.13E-02 1.57E-02 1.61E+01 9.78E-04 Sr-90 2.87E+01 1.49E+01 4.36E+01 3.99E+02 1.09E-01 6-38
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1255 6.6.6.
1256 6.6.7.6.6.6. BFM Groundwater Dose Factors 1257 BFM GW Dose Factors are dose conversion factors in units of mrem/yr per mCi total inventory.
1258 The Resident Farmer dose includes the exposure pathways listed in section 6.5.4. The BFM GW 1259 Dose Factor accounts for all of the exposure pathways, except the drilling spoils pathway which 1260 is addressed in section 6.6.7. The BFM GW Dose Factor is calculated using Equation 6-3. BFM 1261 GW Dose Factors were calculated for each Basement and each ROC in TSD 14-010 and are 1262 provided in Table 6-196.
1263 Equation 6-3 1264 (, )
1265 = (, ) x ()
1266 where:
1267 BFM GW Dose Factor (i,b) = BFM GW Dose Factor for radionuclide (i) and 1268 Basement (b) (mrem/y per mCi) 1269 GW Concentration Factor (i,b) = Groundwater Concentration Factor for 1270 Radionuclide (i) and Basement (b) (pCi/L per mCi) 1271 GW Exposure Factor (i,b) = Groundwater Exposure Factor for Radionuclide (i) 1272 and Basement (b) (mrem/yr per pCi/L) 1273 1274 Table 6-196-16 BFM GW Dose Factors (mrem/yr per mCi Total Inventory)
Crib House Auxiliary Containment Fuel(1) Turbine /Forebay WWTF (mrem/yr (mrem/yr (mrem/yr (mrem/yr (mrem/yr (mrem/yr Nuclide per mCi) per mCi) per mCi) per mCi) per mCi) per mCi) 2.85E-032.45E-Co-60 1.00E-04 1.14E-02 NA 2.87E-03 03 5.21E-01 NA 4.91E-024.22E-Cs-134 9.27E-03 1.98E-01 4.94E-02 02 9.03E+00 NA 3.90E-023.35E-Cs-137 2.64E-02 1.57E-01 3.92E-02 02 7.17E+00 NA 9.64E-048.29E-Eu-152 5.96E-05 3.87E-03 9.69E-04 04 1.75E-01 NA 1.40E-031.20E-Eu-154 6.77E-05 5.62E-03 1.41E-03 03 2.56E-01 NA 6.75E-035.80E-H-3 6.21E-03 2.72E-02 6.80E-03 03 1.23E+00 Ni-63 2.86E-04 1.61E-03 NA 4.01E-04 4.00E-043.44E- 7.31E-02 6-39
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 04 NA 1.12E+009.66E-Sr-90 3.29E-01 4.51E+00 1.13E+00 01 2.06E+02 1275 (1)Note 1: As discussed in section 6.5.4, the BFM GW Dose Factors are not applicable to the SFP/Transfer 1276 Canal.
1277 Table 6-19 includes an adjustment to the Table 6-18 peak groundwater concentration factors for 1278 the Crib House/Forebay. A revision to the demolition plan for the Crib House/Forebay was made 1279 that entailed leaving interior walls as opposed to removing them. This resulted in a decrease in 1280 the basement mixing volume as compared to that assumed in the DUST-MS modeling provided 1281 in TSD-14-009 and a corresponding increase in the fill and groundwater concentrations 1282 calculated in TSD 14-009. The BFM GW DFs are directly proportional to the groundwater 1283 concentrations which are inversely proportional to the ratio of revised/original mixing volumes.
1284 The ratio of the revised/original mixing volumes for the Crib House /Forebay was calculated in 1285 TSD 14-014, Revision 1 and determined to be 0.86. The Crib House/Forebay BFM GW Dose 1286 Factors were therefore adjusted higher by the inverse of 0.86 or a factor of 1.16. Note that the 1287 Crib House/Forebay surface area was also adjusted to account for the additional remaining walls 1288 but the change in surface area does not affect the calculation of the BFM Dose Factors because 1289 the unit inventory approach used was independent of surface area.
1290 6.6.8.6.6.7. BFM Drilling Spoils Dose Factors 1291 The BFM Drilling Spoils scenario addresses one of the BFM exposure pathways listed in 1292 section 6.5.4 by calculating the dose from residual radioactivity in fill material (resulting from 1293 release from surfaces to clean fill after backfill) which is brought to the surface during the 1294 installation of a well in the basement. The activity remaining in the concrete surfaces, if any, is 1295 also included in the drilling spoils source term. The drilling spoils exposure pathway was 1296 included after initial screening in ZionSolutions TSD 14-021 Basement Fill Model (BFM) 1297 Drilling Spoils and Alternate Exposure Scenarios (Reference 6-28) indicated that the pathway 1298 could potentially contribute greater than 10% of the total BFM dose. TSD 14-021 also provides 1299 the BFM Drilling Spoils Dose Factor calculations. BFM Drilling Spoils Dose Factors are 1300 calculated in units of mrem/yr per mCi total inventory. and added to the BFM GW Dose Factors 1301 in Table 6-16. The sum of the dose factors are then used to calculate the final Basement Dose 1302 Factor which will be used to demonstrate compliance with the 25 mrem/yr Dose Criterion based 1303 on the total inventory remaining at license termination.
1304 The source term for the BFM Drilling Spoils scenario is the average concentration in fill, and 1305 remaining in concrete, at the time of maximum groundwater concentration which is the time 1306 used to assess exposure for all other BFM pathways. As discussed previously, the fill is clean at 1307 the time of license termination but is assumed to adsorb activity after release from the concrete 1308 surfaces (or steel liner for Containment).
1309 For Basements with instant release assumptions, the maximum groundwater concentrations 1310 occur at t=0 for all radionuclides. The remaining fraction in concrete is assumed to be zero since 1311 all activity is released to the water. For Basements with diffusion controlled release (the 1312 Auxiliary Basement and the SFP/Transfer Canal), the time of maximum groundwater (and fill) 1313 concentrations is a function of half-life and diffusion coefficient, and therefore radionuclide-6-40
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1314 specific. The corresponding fractions of inventory remaining in concrete at the time of 1315 maximum groundwater concentration are also radionuclide-specific. To ensure conservatism 1316 and consistency in the BFM source term, the maximum fill concentrations (which occur at the 1317 time of maximum groundwater concentrations) are applied for each radionuclide regardless of 1318 when the maximum occurs.
1319 There are a number of ways that installers handle and dispose of drilling spoils, including the use 1320 of slurry pits, tanks, and dumping the drilling spoils on the existing surface soils. The use of pits 1321 would likely involve additional dilution by refilling the pit with the material excavated during its 1322 construction. As a conservative assumption, no dilution of the spoil material is assumed after 1323 being brought to the surface.
1324 The borehole diameter is assumed to be 8 inches to accommodate the installation of a 4 inch 1325 diameter casing. The well is assumed to be drilled into the basement fill down to the concrete 1326 floor where refusal is met and drilling stopped. The extent of drilling into concrete is 1327 conservatively assumed to be sufficient to capture 100 percent of the remaining residual 1328 radioactivity in concrete. The volume of spoil material brought to the surface is calculated based 1329 on the borehole diameter and depth of drilling which is defined as the distance from the ground 1330 surface to the bottom of the Basement. All material, including the concrete, fill, and clean 1331 overburden is brought to the surface where it is uniformly mixed and spread over a circular area 1332 to a depth of 0.15 m.
1333 The dose from the circular area at the surface is calculated using the surface soil DCGLs and 1334 Area Factors (AF) (see section 6.9 for soil DCGL calculations). As described in TSD 14-021, 1335 the size of the area over which the drilling spoils are spread ranges from 0.92 m2 to 3.56 m2, 1336 depending on the Basement. The BFM Drilling Spoils Dose Factors are calculated in TSD 14-1337 021 for each Basement and each ROC and are provided Table 6-20. Note that the Drilling Spoils 1338 Dose Factors for H-3 are all zero because the distribution coefficient is zero and there is no 1339 adsorption onto fill or remaining in concrete.
6-41
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1340 Table 6-206-17 BFM Drilling Spoils Dose Factors (mrem/yr per mCi Total Inventory)
Turbine Crib House WWTF Auxiliary Containment Fuel (mrem/yr /Forebay (mrem/yr Nuclide (mrem/yr (mrem/yr (mrem/yr (mrem/yr per per mCi) per mCi) per mCi) per mCi) per mCi) mCi)
Co-60 1.07E-02 2.97E-02 1.58E-01 9.58E-03 2.07E-021.78E-02 2.26E-01 Cs-134 6.29E-03 1.72E-02 9.41E-02 5.54E-03 1.19E-021.02E-02 1.31E-01 Cs-137 3.22E-03 7.27E-03 4.83E-02 2.35E-03 5.05E-034.34E-03 5.57E-02 Eu-152 5.02E-03 1.38E-02 7.46E-02 4.45E-03 9.58E-038.24E-03 1.05E-01 Eu-154 5.57E-03 1.46E-02 8.25E-02 4.73E-03 1.02E-028.77E-03 1.12E-01 H-3 0.00E+00 0.00E+00 1.45E-09 0.00E+00 0.00E+000.00E+00 0.00E+00 3.785E- 1.864E- 4.81E-084.11E-08 Ni-63 3.231E-08 5.6157E-08 4.163E-07 07 08 6.265.84E- 7.6009E- 4.361E- 1.16E-049.30E-05 9.61.049E-Sr-90 1.309E-04 05 04 05 04 1341 Table 6-20 includes an adjustment to the Table 6-18 peak groundwater concentration factors for 1342 the Crib House/Forebay which are directly proportional to the peak fill concentrations used in the 1343 Drilling Spoils scenario. A revision to the demolition plan for the Crib House/Forebay was made 1344 that entailed leaving interior walls as opposed to removing them. This resulted in a decrease in 1345 the basement mixing volume as compared to that assumed in the DUST-MS modeling provided 1346 in TSD-14-009 and a corresponding increase in the fill and groundwater concentrations 1347 calculated in TSD 14-009. The Drilling Spoils Dose Factors are directly proportional to the fill 1348 concentrations which are inversely proportional to the ratio of revised/original mixing volumes.
1349 The ratio of the revised/original mixing volumes for the Crib House /Forebay was calculated in 1350 TSD 14-014, Revision 1 and determined to be 0.86. The Crib House/Forebay BFM Drilling 1351 Spoils DFs were therefore adjusted higher by the inverse of 0.86 or a factor of 1.16. Note that the 1352 Crib House/Forebay surface area was also adjusted to account for the additional remaining walls 1353 but the change in surface area does not affect the calculation of the BFM Dose Factors because 1354 the unit inventory approach used was independent of surface area.
1355 1356 6.6.9.6.6.8. Basement Surface DCGLsDose Factors 1357 Derived Concentration Guideline Levels, in units of pCi/m2 of basement surface area, were 1358 calculated in Reference 6-13, section 2.5 for the BFM Groundwater and BFM Drilling Spoils 1359 scenarios individually and are designated as the DCGLBS (Basement Scenario DCGLs). The 1360 Groundwater DCGLBS and Drilling Spoils DCGLBS are combined to generate the Basement 1361 DCGL (DCGLB) which represent the combined dose from both the groundwater and drilling 1362 spoils scenarios. The DCGLB is directly analogous to the DCGLW as defined in MARSSIM and 1363 is the DCGL used during FSS to demonstrate compliance.
6-42
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1364 A DCGL was calculated for each basement surface survey unit. For the purpose of this 1365 calculation, a surface includes all concrete walls and floors of the basements or the steel liner 1366 on the walls and floors of Containment. The areal extent of the walls and floors is the surface 1367 area and includes all contamination, volumetric at depth and on the surface, within the defined 1368 area. Note that embedded pipe and penetrations will remain in the basements. Embedded pipe 1369 and penetrations within or interfacing each basement structure were designated as separate 1370 survey units, with separate DCGL calculations for each, as described in sections 6.13 and 6.14.
1371 After the basement surface areas were adjusted as described in section 6.6.8.1, the DCGLBS 1372 values were calculated for each basement using Equation 6-4. Adjustment factors of 0.90 for 1373 Containment and 0.95 for all other basements are included in Equation 6-4 to account for the 1374 dose from insignificant contributors (see section 6.5.2.3). The DCGLB values were calculated by 1375 combining the Groundwater and Drilling Spoils DCGLBS values using Equation 6-5.
1376 1377 Equation 6-4 25 1 1378 , = 1 + 09
()
1379 1380 Where:
1381 DCGLBS, i = Groundwater or Drilling Spoils scenario DCGL for radionuclide 1382 (i) (pCi/m2) 1383 BFM Scenario DFi = Basement Fill Model Dose Factor for radionuclide (i) (mrem/yr 1384 per mC) 1385 1E+09 = Conversion factor (pCi/mCi) 1386 25 = 25 mrem/yr dose criterion 1387 SAb (adjusted) = Adjusted surface area of basement (b) (m2) 1388 IC Dose Adjustment = Insignificant Contributor Dose Adjustment Factor (0.9 for 1389 Containment and 0.95 for all other basements - see section 6.5.2.3) 1390 1391 1392 1393 1394 Equation 6-5 1
1395 =
1 1
+
1396 Where:
1397 DCGLBi = Basement Surface DCGL for radionuclide (i) 1398 (pCi/m2) 6-43
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1399 GW DCGLBSi = Groundwater scenario DCGL for radionuclide (i) (mrem/yr per 1400 mCi) 1401 DS DCGLBSi = Drilling Spoil scenario DCGL for radionuclide (i) (mrem/yr per 1402 mCi) 1403 6.6.8.1. Basement Surface Area Adjustments 1404 Basement surface area adjustments were required to ensure that the DCGLs account for the 1405 contribution of residual radioactivity from basements/structures that cannot, on their own, 1406 support a water supply well but are hydraulically connected to a basement that can support a 1407 well. These include the Circulating Water Intake Pipes, Circulating Water Discharge Tunnels 1408 (and associated piping) , Buttress Pits/Tendon Tunnels, and the SFP/Transfer Canal. The surface 1409 area adjustments result in lowering the DCGL concentrations (pCi/m2) in the affected basements 1410 and structures, from that which would be calculated for each individually, by requiring the 1411 allowable total activity to be uniformly distributed over the larger, combined surface areas.
1412 The first area adjustment is to the Turbine Basement and Crib House/Forebay. As stated in 1413 Table 6-9, the activity in the Circulating Water Intake Pipes is included in both the Crib 1414 House/Forebay and the Turbine Basement. The activity in the Circulating Water Discharge 1415 Tunnels is included with the Turbine Basement. The Intake Pipe has been grouted essentially 1416 eliminating the hydraulic connections. The major hydraulic connections between the Discharge 1417 Tunnels and the Turbine basement will be isolated as a part of the decommissioning process but 1418 two 48 inch diameter service water pipes that run between the Turbine Basement and the 1419 Discharge Tunnels will remain open and maintain the hydraulic connection, at least to some 1420 extent. For the purpose of the DCGL calculation, the hydraulic connections to the Intake Pipe 1421 and Discharge Tunnels are assumed to be fully regained in the future after degradation of the 1422 isolation barriers and grout.
1423 The surface DCGL calculations account for the activity in the Intake Pipes and Discharge 1424 Tunnels by summing the surface areas of the connected structures and using the summed areas 1425 for the DCGL calculation. The Intake Pipe surface area is added to the Crib House/Forebay. The 1426 Intake Pipe is also connected to the Turbine basement and therefore, the Intake Pipe surface area 1427 is also added to the Turbine Basement. The activity in the Intake Pipe is conservatively assumed 1428 to be in both basements simultaneously. The Discharge Tunnel surface area is added to the 1429 Turbine Basement. There is also a group of pipes that are within the Turbine building and 1430 connected to the Discharge Tunnels including the remaining portions of the 12 foot diameter 1431 downcomer pipes, the 36 inch and 48 inch diameter standpipes, and the 48 inch diameter service 1432 water return pipes. There are also large diameter pipes on the east side of the Discharge Tunnel 1433 Valve House. The internal surface areas of these Circulating Water Discharge Pipes are also 1434 added to the summed area used for the Turbine Basement DCGL calculation.
1435 1436 The summed areas were then used as the SAb (adjusted) term in Equation 6-4 to calculate the 1437 DCGLs for the Crib House/Forebay and Turbine Basement. As seen in Equation 6-4, increasing 1438 the surface area decreases the DCGLs. The lower DCGLs calculated for the Crib House/Forebay 1439 and Turbine Basement, based on the summed areas, were then also applied to the Intake Pipes 1440 and Discharge Tunnels, respectively. The lower DCGL for either the Crib House/Forebay or the 6-44
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1441 Turbine Basement will be applied to the Intake Pipe. However, this is a minor distinction given 1442 that FSS measurements in the Intake Pipe have all been below detection limits which are orders 1443 of magnitude below the DCGLs. The Discharge Tunnel FSS results will be included in the dose 1444 assessment for the Turbine Basement. The Intake Pipe FSS results will be included with both the 1445 Crib House/Forebay and Turbine Basement dose assessments (see LTP Chapter 5, section 5.5.7.
1446 for discussion of basement surface dose assessment) 1447 A second surface area adjustment was required to account for the contribution of residual 1448 radioactivity in the SFP/Transfer Canal to the groundwater pathway. As discussed in section 1449 6.5.4, the SFP/Transfer Canal geometry could not support a water well and therefore the BFM 1450 Groundwater Dose Factor was set to zero (see Table 6-19). However, the potential for the 1451 residual radioactivity in the SFP/Transfer Canal to contribute to the groundwater pathway is 1452 accounted for by adding the SFP/Transfer Canal surface area to the Containment Basement and 1453 Auxiliary Basement surface areas in the DCGL calculation. The activity could mix with the 1454 Containment Basement through the Fuel Transfer Tube. Activity could mix with the Auxiliary 1455 Basement through an opening created by removing the wall between the Transfer Canal and 1456 Auxiliary Basement during demolition. The surface area adjustment, and corresponding DCGL 1457 calculations, conservatively assume that the activity in the SFP/Transfer Canal is in both the 1458 Containment and Auxiliary Basement simultaneously.
1459 The Buttress Pits and Tendon Tunnels are hydraulically connected to the Steam Tunnels. The 1460 surface areas of these structures are therefore added to the Turbine Basement.
1461 The inputs to the calculation of adjusted surface areas are provided in Tables 6-21 to 6-23. The 1462 SFP/Transfer Canal and WWTF do not require adjustment. The surface areas in Table 6-21 were 1463 used in the DCGL calculations for the SFP/Transfer Canal and WWTF. The DCGL calculations, 1464 using Equations 6-4 and 6-5, are performed and documented in Reference 13, section 2.5.
1465 Table 6-216-20 Basement Surface Areas (Walls and Floors)
Basement Wall and Floor Surface Area (1) m2 Auxiliary Basement 6503 Containment Basement 2759 Turbine Building Basement 14864 SFP/Transfer Canal 723 Crib House/Forebay 13842 WWTF 1124 1466 (1)
Reference:
TSD 14-014 Revision 1, Table 64 1467 6-45
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1468 Table 6-22 Surface Areas for Circulating Water Intake Pipe, Circulating 1469 Water Discharge Tunnel, Circulating Water Discharge Pipes and 1470 Buttress Pits/Tendon Tunnels Structure Surface Area Surface Area ft2 m2 Circulating Water Discharge Tunnels (1) 52400 4868 Circulating Water Intake Pipes (2) 47491 4412 Circulating Water Discharge Pipes (3) 11570 1075 Buttress Pits/Tendon Tunnels (4) 20626 1916 1471 (1) Reference TSD 14-014, Table 64.
1472 (2) TSD 14-016, Table 46 1473 (3) TSD 14-016, Table 50.
1474 (4) TSD 14-014, Rev 3, Table s 60 & 63 and TSD 13-005 Rev 1 Table 15 1475 1476 Table 6-23 Adjusted Basement Surface Areas for DCGL Calculation Basement Structures Included in Total Total SA/V Calculation SA m2 Containment Containment + SFP/Transfer Canal 3482 Auxiliary Auxiliary + SFP/Transfer Canal 7226 Turbine Turbine + Circulating Water Discharge Tunnel +
Circulating Water Intake Pipe + Circulating Water 27135 Discharge Pipes + Buttress Pits/Tendon Tunnels Crib House/Forebay Crib House/Forebay + Circulating Water Intake 18254 Pipe SFP/Transfer Canal (1) SFP/Transfer Canal 723 WWTF1 WWTF 1124 1477 (1) No area adjustment required. The basement surface areas in Table 6-21 1478 are used in the DCGL calculation.
1479 The Groundwater and Drilling Spoils DCGLBS values were calculated using Equation 6-4 with 1480 inputs from the BFM Dose Factors in Tables 6-19 and 6-20, respectively, and the surface areas in 1481 Table 6-23 for the SAb (adjusted) term. The results are provided in Tables 6-24 and 6-25. The 1482 DCGLB values were calculated using Equation 6-5 with results provided in Table 6-26.
1483 1484 1485 1486 6-46
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1487 1488 1489 1490 1491 1492 Table 6-24 Adjusted BFM Groundwater Scenario DCGLBS (Adjusted for IC Dose)
SFP/
Auxiliary Transfer Crib House/
Nuclide Containment Canal Turbine Forebay WWTF (pCi/m )
2 (pCi/m2) ((pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2)
Co-60 3.28E+10 5.65E+08 NA 3.05E+08 4.57E+08 4.05E+07 Cs-134 3.55E+08 3.27E+07 NA 1.77E+07 2.65E+07 2.34E+06 Cs-137 1.25E+08 4.12E+07 NA 2.23E+07 3.34E+07 2.95E+06 Eu-152 5.52E+10 1.67E+09 NA 9.03E+08 1.35E+09 1.21E+08 Eu-154 4.85E+10 1.15E+09 NA 6.22E+08 9.29E+08 8.24E+07 H-3 5.30E+08 2.38E+08 NA 1.29E+08 1.93E+08 1.71E+07 Ni-63 1.15E+10 4.02E+09 NA 2.18E+09 3.25E+09 2.89E+08 Sr-90 9.98E+06 1.43E+06 NA 7.74E+05 1.16E+06 1.03E+05 1493 1494 1495 Table 6-25 Adjusted BFM Drilling Spoils Scenario DCGLBS (Adjusted for IC Dose)
SFP/ Crib Transfer House/
Nuclide Auxiliary Containment Canal Turbine Forebay WWTF (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2)
Co-60 3.07E+08 2.18E+08 2.08E+08 9.13E+07 6.28E+07 9.34E+07 Cs-134 5.23E+08 3.77E+08 3.49E+08 1.58E+08 1.09E+08 1.61E+08 Cs-137 1.02E+09 8.89E+08 6.80E+08 3.73E+08 2.58E+08 3.80E+08 Eu-152 6.54E+08 4.69E+08 4.41E+08 1.97E+08 1.36E+08 2.01E+08 Eu-154 5.91E+08 4.41E+08 3.98E+08 1.85E+08 1.28E+08 1.89E+08 H-3 2.26E+15 4.45E+15 2.26E+16 6.02E+14 8.95E+14 1.45E+16 Ni-63 1.02E+14 1.15E+14 8.69E+13 4.71E+13 2.70E+13 5.08E+13 Sr-90 5.25E+10 4.63E+10 4.32E+10 1.90E+10 1.12E+10 2.03E+10 1496 1497 6-47
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1498 Table 6-26 Adjusted Basement DCGLB (Adjusted for IC Dose)
SFP/
Transfer Crib House/
Auxiliary Containment Canal (1) Turbine Forebay WWTF Nuclide (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2)
Co-60 3.04E+08 1.57E+08 1.57E+08 7.03E+07 5.52E+07 2.83E+07 Cs-134 2.11E+08 3.01E+07 3.01E+07 1.59E+07 2.13E+07 2.31E+06 Cs-137 1.11E+08 3.94E+07 3.94E+07 2.11E+07 2.96E+07 2.93E+06 Eu-152 6.47E+08 3.66E+08 3.66E+08 1.62E+08 1.23E+08 7.55E+07 Eu-154 5.83E+08 3.19E+08 3.19E+08 1.43E+08 1.12E+08 5.74E+07 H-3 5.30E+08 2.38E+08 2.38E+08 1.29E+08 1.93E+08 1.71E+07 Ni-63 1.15E+10 4.02E+09 4.02E+09 2.18E+09 3.25E+09 2.89E+08 Sr-90 9.98E+06 1.43E+06 1.43E+06 7.74E+05 1.16E+06 1.03E+05 1499 (1) DCGL for SFP/Transfer Canal set equal to the lower of either the Auxiliary or Containment DCGL 1500 Containment DCGL was lower for all ROC therefore SFP/Transfer Canal DCGL set equal to Containment 1501 Compliance with the 25 mrem/yr Dose Criterion will be demonstrated after the remaining 1502 residual radioactivity inventory has been determined by STS in accordance with the methods 1503 described in Chapter 5, section 5.3.3. The total inventory remaining for each ROC, in each 1504 Basement, will be multiplied by the applicable Basement Dose Factor. The dose contribution for 1505 each ROC in a given Basement will be accounted for using the sum of fractions rule.
1506 The Basement Dose Factors are calculated as the sum of the BFM GW Dose Factors and BFM 1507 Drilling Spoils Dose Factors which together account for the dose from all of the Resident Farmer 1508 exposure pathways listed in section 6.5.4. As discussed in section 6.5.4, only the BFM Drilling 1509 Spoils Dose Factors are applicable to the SFP, i.e., the BFM GW Dose Factors are assumed to be 1510 zero.
1511 An additional step in the calculation of the Basement Dose Factors is adjustment for the dose 1512 contribution from insignificant dose contributors. In accordance with NUREG 1757, the 1513 insignificant radionuclides can be removed from detailed assessment but the dose attributable to 1514 the removed radionuclides must be accounted for. From Table 6-3, the insignificant contributor 1515 dose contribution for the Containment and Auxiliary Basements was 0.514% and 1.207%,
1516 respectively. The Auxiliary Basement percentage will be applied to all Basements except 1517 Containment, noting that the radionuclide mixtures will be reviewed and revised if necessary 1518 based on results of continued characterization, RASS and STS (see LTP Chapter 5, section 5.1).
1519 The Basement Dose Factors are calculated using Equation 6-4.
1520 The insignificant contributor dose adjustment factors in Equation 6-4 are 1.00517 (1/.9948) and 1521 1.0122 (1/0.9879) for the Containment Basement and all other Basements, respectively. The 1522 final Basement Dose factors for each Basement and ROC are listed in Table 6-18.
6-48
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1523 A final adjustment higher by a factor of 7.5 was made to the SFP/Transfer Canal Basement Dose 1524 Factors only to account for the dose from an unlikely alternate excavation scenario (see section 1525 6.7).
1526 Equation 6-4 1527 (, ) = ( (, ) + (, ))
1528 where:
1529 BDF (b,i) = Basement Dose Factor for Basement (b) and radionuclide (i) (mCi) 1530 BFM DF (b,i) = BFM Dose Factor for Basement (b) and radionuclide (i) (mrem/yr per mCi) 1531 DS DF (b,i) = Drilling Spoils Dose Factor for Basement (b) and radionuclide (i) (mrem/yr per 1532 mCi) 1533 IC Dose Adjustment = adjustment factor to account for the insignificant contributor dose from 1534 Table 6-3 1535 Table 6-18 Basement Dose Factors Crib House/
Auxiliary Containmen Fuel Turbine WWTF Forebay Nuclid t (mrem/mCi (mrem/mCi (mrem/mCi (mrem/mCi (mrem/mCi e ) (mrem/mCi) ) ) )
)
Co-60 1.10E-02 4.13E-02 1.20E+00 1.26E-02 2.05E-02 7.57E-01 Cs-134 1.57E-02 2.16E-01 7.15E-01 5.56E-02 5.31E-02 9.27E+00 Cs-137 3.00E-02 1.65E-01 3.67E-01 4.21E-02 3.83E-02 7.31E+00 Eu-152 5.14E-03 1.77E-02 5.66E-01 5.48E-03 9.18E-03 2.83E-01 Eu-154 5.70E-03 2.04E-02 6.26E-01 6.21E-03 1.01E-02 3.73E-01 H-3 6.28E-03 2.73E-02 1.10E-08 6.88E-03 5.87E-03 1.25E+00 Ni-63 2.89E-04 1.61E-03 2.85E-06 4.06E-04 3.48E-04 7.40E-02 Sr-90 3.33E-01 4.54E+00 5.38E-03 1.15E+00 9.78E-01 2.09E+02 1536 6.6.9. Basement Surface Area Factors and Elevated Measurement ComparisonFill 1537 Model Elevated Area Consideration 1538 Class 1 survey units that pass the Sign test but have small areas with concentrations exceeding 1539 the DCGLB are also tested to demonstrate that these small areas meet the dose criterion using the 1540 Elevated Measurement Comparison (EMC). There are currently three Class 1 areas at Zion, the 6-49
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1541 Auxiliary Basement, the SFP/Transfer Canal and the Containment Under-Vessel area (see LTP 1542 Chapter 5 Table 5-12 for survey unit designations in all basements).
1543 Area Factors (AF) are required to perform the EMC test. The AF is defined as the magnitude by 1544 which the concentration within the small area of elevated activity can exceed the DCGLB while 1545 maintaining compliance with the dose criterion.
1546 As described above, the BFM includes two environmental transport/dose pathway scenarios, 1547 Groundwater and Drilling Spoils. The AF considerations are different for the two scenarios due 1548 to differences in the source term pathway and transport mechanisms. The DCGLB combines the 1549 dose from both the Groundwater and Drilling Spoils scenarios and is the DCGL used to 1550 demonstrate compliance based on FSS ISOCS measurements.
1551 The BFM is a mixing model that is independent of the distribution of the residual radioactivity.
1552 The calculation of the DCGLB values support the mixing assumption by assuming uniform 1553 contamination over all basement walls and floors. An individual FSS ISOCS measurement that 1554 exceeds the DCGLB could conceptually be acceptable if it satisfies an EMC test for the 1555 Groundwater scenario. For example, assuming full mixing, the AF for an Auxiliary Basement 1556 FSS ISOCS measurement could be as high as the total surface area divided by the ISOCS FOV 1557 (7226/28 = 258). However, consistent with the bounding approach used to develop the 1558 conceptual model, and to support the assumption of uniform mixing, no AF will be assigned to 1559 the Groundwater scenario. Any FSS ISOCS result exceeding the DCGLB will be investigated and 1560 remediated as necessary.
1561 Elevated areas on floors that are smaller than the FSS ISOCS FOV and exceed the DCGLB are 1562 subject to the EMC test for the BFM Drilling Spoils scenario as described below.
1563 6.6.9.1. Basement Surface Area Factor for BFM Drilling Spoils Scenario 1564 An AF for the BFM Drilling Spoils Scenario was calculated for the EMC Test. The Drilling 1565 Spoils AF applies to floors only. An AF is required for all Class 1 survey units which include the 1566 Auxiliary Basement, SFP/Transfer Canal, and the Under-Vessel area of Containment.
1567 The AF is based on the assumption that all of the activity is on the floor as opposed to the being 1568 distributed over the walls and floors as conservatively assumed in the DCGLBS calculation. If all 1569 of the allowable activity is distributed over the floor only, the activity in the drilling spoils after 1570 contacting the floor will result in 25 mrem/yr (as required by the AF definition). This is a 1571 conservative approach because all of the measured activity must either remain in the concrete 1572 after license termination or be released to a hypothetical 8 inch diameter column of fill directly 1573 above the elevated area with no horizontal mixing.
1574 The first step in the AF calculation is to modify the DCGLBS in Table 6-25 by the ratio of total 1575 surface area (walls and floors) to the floor surface area only. This results in concentration 1576 (pCi/m2) on the floor that would result in 25 mrem/yr for the drilling spoils pathway only. The 1577 Drilling Spoils AF is then calculated by dividing the modified Drilling Spoils DCGLBS by the 1578 DCGLB. The AF calculation is shown in Equation 6-6. The basement floor areas and the 1579 resulting AFs are provided in Tables 6-27 and 6-28 (the total surface areas are provided in Table 1580 6-23). The calculations are documented in Reference 6-13.
1581 6-50
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1582 1583 Equation 6-6 1584 , =
1585 1586 Where:
1587 Drilling Spoils AFb.i = Drilling Spoils Area Factor for basement (b) and 1588 radionuclide(i) 1589 SAtotal,b = Total surface area of walls and floors in Basement (b) 1590 SAfloor = Floor surface area in Basement (b) 1591 Drilling Spoils DCGLBS,i = Drilling Spoils DCGL for Basement (b) and radionuclide 1592 (i) from Table 6-25 1593 Drilling Spoils DCGLB,i = DCGLB for Basement (b) and radionuclide (i) from Table 1594 6-26 1595 1596 1597 1598 1599 1600 Table 6-27 Floor Surface Areas for Class 1 Basements Basement Floor Surface Floor Surface Area (1) Area ft2 m2 SFP/Transfer Canal 2448 227 Auxiliary Basement 27149 2522 Containment 16489 1532 1601 (1) Reference TSD 14-021, Revision 1, Table 2 1602 1603 Table 6-28 Drilling Spoils Scenario Area Factors Auxiliary Spent Fuel Containment Pool/Transfer Under-Vessel Canal Area Co-60 2.89E+00 4.20E+00 3.15E+00 Cs-134 7.09E+00 3.69E+01 2.84E+01 Cs-137 2.63E+01 5.49E+01 5.13E+01 6-51
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Eu-152 2.90E+00 3.82E+00 2.91E+00 Eu-154 2.90E+00 3.97E+00 3.15E+00 H-3 1.22E+07 3.02E+08 4.25E+07 Ni-63 2.53E+04 6.87E+04 6.51E+04 Sr-90 1.51E+04 9.60E+04 7.36E+04 1604 After remediation and demolition is completed, debris removed, and surfaces cleaned, a 100%
1605 scan survey will be performed on the Class 1 basement floors using conventional gamma 1606 instruments in typical scanning and measurement modes. Elevated areas that could potentially 1607 exceed the DCGLB will be identified and bounded (see LTP Chapter 5 for discussion of scanning 1608 instrumentation and MDC). A concrete core sample will be collected at the location within the 1609 bounded area that exhibits the maximum reading and the activity quantified. If the total activity 1610 in the core, including all core slices with depth, exceeds the DCGLB, the EMC test will be 1611 performed using the AFs in Table 6-28. Note that as discussed in LTP Chapter 5, section 5.4.3, 1612 any areas identified as potentially exceeding the DCGLB during the Contamination Verification 1613 Survey will also be identified as a location for a judgmental ISOCS measurement during FSS.
1614 The EMC test will be performed for the Class 1 basement surface survey units using Equation 5-1615 6 in LTP Chapter 5. The DCGLEMC required in Equation 5-6 will be calculated using Equation 6-1616 7. If there is more than one contiguous, bounded, elevated area identified with a core exceeding 1617 the DCGLB, a separate term will be included in Equation 5-6 for each elevated area.
1618 1619 1620 Equation 6-7 1622 () = AFb ()
1621 Where:
1623 DCGLEMC(B) = DCCL for Elevated Measurement Comparison in 1624 basement (b) (pCi/m2) 1625 AF(b) = Area Factor for basement (b) from Table 6-28 1626 DCGLB(b) = DCGLB for basement (b) (pCi/m2) 1627 1628 The BFM is a mixing model that uses the total inventory as the source term and is independent of 1629 the concentration and distribution of the residual radioactivity. The standard approach for 1630 calculating AFs in conjunction with concentration-based DCGLs to determine the acceptability 1631 of elevated areas of activity, as defined in NUREG-1575, Multi-Agency Radiation Survey and 1632 Site Investigation Manual (MARSSIM) (Reference 6-29), does not apply.
1633 Although AFs are not applicable to the BFM, the maximum concentrations that could remain in 1634 the Basements are limited by the implementation of the open air demolition limits described in 1635 TSD 10-002. The Basements will be remediated to the open air demolition limits prior to 1636 demolition of structures above 588 foot elevation. The open air demolition limits are:
1637 Less than 2 mR/hr beta-gamma total surface contamination on contact with structural concrete.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1638 Less than 1,000 dpm/100cm2 beta-gamma loose surface contamination.
1639 These limits define the acceptable operational levels of fixed (as measured by contact exposure 1640 rate) and removable contamination that can remain prior to open air demolition. The limits 1641 ensure that the dose to the public from airborne contamination generated during demolition is 1642 acceptable. The open air demolition limits are operational levels and are not a part of the 1643 compliance calculations for 10 CFR 20.1402.
1644 To comply with the open air demolition limits, radiological surveys will be performed using 1645 approved procedures prior to demolition. These surveys will use conventional gamma 1646 instruments in typical scanning and measurement modes. Scanning coverage for pre-remediation 1647 surveys on structures prior to open air demolition could include up to 100% of the accessible 1648 surface area depending on the contamination potential. The pre-remediation surveys performed 1649 to prepare building surfaces for open air demolition will provide confidence that contamination 1650 above the limits will be identified and remediated.
1651 The characterization data for the Auxiliary Building was reviewed in TSD 14-021 to determine 1652 the hypothetical maximum contamination levels and depth profiles that could remain and meet 1653 the 2 mR/hr open air demolition exposure rate limit. The Auxiliary Basement is expected to 1654 have the highest remaining inventory after remediation is completed. Based on the highest 1655 Cs-137 activity identified in core samples from the Auxiliary Basement floor at 542 foot 1656 elevation (from the 2A RHR Pump Room), the worst-case concentrations of Cs-137 that could 1657 remain after remediation to the open air demolition criteria were estimated. The concentrations 1658 after remediation were estimated to range from 12,234 pCi/g in the first 0.5 inch to 719 pCi/g at 1659 a depth of 3 inches. Note that the highest concentrations are limited to a small area of 1660 approximately 20 m2 on the Auxiliary Basement floor. For comparison, the average Cs-137 1661 concentrations over the first 2 inches of the entire Auxiliary Basement floor at the 542 foot 1662 elevation floor is 239 pCi/g (Reference 14-019). The maximum and average concentrations of 1663 Co-60 are much lower, consistent with the radionuclide mixture provided in Table 6-3.
1664 As previously stated, the BFM is a mixing model that uses the total inventory in each Basement 1665 as the source term and the calculated dose is independent of the range and distribution of residual 1666 radioactivity. Therefore, the hypothetical worst-case concentrations described above for the 1667 Auxiliary Building are acceptable, assuming that the inventory in the assumed isolated elevated 1668 areas is included in the total inventory used for the BFM source term. To further risk-inform 1669 the acceptability of the worst-case concentrations, TSD 14-021 evaluates the potential dose 1670 consequences of this activity.
1671 The dose was assessed using a Worst-Case drilling spoils scenario based on the same 1672 assumptions used in the BFM Drilling Spoils scenario described in section 6.6.7, with the 1673 exception that the highest concentrations that could hypothetically remain in the Auxiliary 1674 Basement after remediation to the open air demolition limits are used as the concrete source 1675 term.
1676 The Worst-Case Drilling Spoils assessment is considered a less likely but plausible scenario 1677 (as defined in NUREG-1757, Table 5.1). Consistent with NUREG 1757, Table 5.1, the scenario 1678 is not analyzed for compliance with the 10 CFR 20.1402 dose criterion, but is used to help risk 1679 inform and justify the decision that the hypothetical maximum concentrations that could remain 1680 in elevated areas after remediation to the 2 mR/hr demolition limit are acceptable, assuming all 6-53
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1681 activity is accounted for and included in the final compliance demonstration using the Basement 1682 Dose Factors.
1683 The Worst-Case Drilling Spoils scenario assumes that the water supply well is drilled directly 1684 into a spot of residual radioactivity with the highest hypothetical concentration immediately after 1685 license termination taking no credit for decay or release to the fill water. The entire inventory in 1686 the spot is assumed to be excavated and brought to the surface while mixing with overburden fill 1687 and soil. This is very unlikely for two reasons. First, the scenario assumes that a Resident 1688 Farmer water supply well is installed immediately after license termination while the ISFSI is 1689 present, which is essentially non-credible land use (as discussed in section 6.5.3). Second, the 1690 probability of an assumed eight inch borehole hitting an area containing the maximum 1691 hypothetical contamination level during drilling is low. For example, the area in the Auxiliary 1692 Basement floor with the highest contamination levels is limited to ~20 m2 (in two RHR rooms) 1693 of the ~2500 m2 total floor area. Note that the dose from the worst-case drilling spoil scenario is 1694 separate and distinct from the BFM dose in that it is assumed to occur before any release of 1695 activity from the concrete and therefore, the water and fill concentrations are zero.
1696 From TSD 14-021, the estimated dose for the Worst-Case Drilling Spoils scenario in the 1697 Auxiliary Basement is 4.2 mrem/yr. The dose from this less likely but plausible scenario is not 1698 significant and less than 25 mrem/yr. Further reduction of the hypothetical maximum elevated 1699 area of residual radioactivity, beyond that required for remediation to meet the 2 mR/hr open air 1700 demolition limit, is not justified on a risk-informed basis. Demonstrating compliance with the 1701 dose criterion using the total inventory and Basement Dose Factors is sufficient to account for 1702 the activity, and assess the dose, in the areas with the hypothetical maximum concentrations.
1703 6.7. Alternate Exposure Scenarios for Backfilled Basements 1704 Two alternate scenarios were evaluated in TSD 14-021 that involve a change to the as left 1705 backfilled geometry in the Resident Farmer scenario. The first entails construction of a house 1706 basement within the fill material. Note that the assumed three meter depth of the basement 1707 excavation is insufficient to encounter fill material potentially containing residual radioactivity 1708 (resulting from leaching of residual radioactivity from surfaces after backfill) assuming the 1709 Basement is not constructed within the saturated zone. However, a simple check of direct 1710 radiation dose, assuming a residual radioactivity inventory at the hypothetical maximum levels 1711 based on the Basement Dose Factors, was conducted to confirm the expectation that the dose 1712 would be negligible. The dose calculation is provided in TSD 14-021 with a result of 1713 0.03 mrem/yr for the Auxiliary Basement and 0.5 mrem/yr for the SFP/Transfer Canal. The 1714 remaining Basements do not contain significant inventories and were not assessed.
1715 The second alternate scenario assumes large scale excavation of parts or all of the backfilled 1716 structural concrete and fill after the ISFSI is decommissioned (assumed to be 510 years after 1717 license termination). A simple calculation was performed to estimate the average concentrations 1718 in the excavated concrete and fill assuming a residual radioactivity inventory at the hypothetical 1719 maximum levels and the ZNPS radionuclide mixture provided in Table 6-3. The assessment was 1720 performed for all basements although only the primarily for the Auxiliary Basement is expected 1721 to contain significant levels of residual radioactivity at license termination. and SFP/Transfer 1722 Canal Basements. The remaining Basements do not contain significant inventories (assuming all 1723 concrete is removed from Containment).
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1724 If a large-scale excavation of the basements were to occur, it would not be for residential use but 1725 to develop the property for industrial use. The cost and technical challenges of the excavation 1726 required for the deep basements, that are all below the water table, would only be justified for a 1727 large scale industrial project that would be present on the site for decades. Therefore, for the 1728 assessment of the large scale industrial excavation scenario an Industrial Use soil DCGL 1729 (DCGLI) was developed assuming an industrial use scenario (see Reference 6-13, section 6). A 1730 period of 10 years was assumed before excavation begins. The DCGLI was used only for the 1731 evaluation of the less likely but plausible alternate excavation scenario and is not proposed for 1732 any compliance demonstration.
1733 The average activity in the excavated concrete and fill was compared to the soil DCGLIS values 1734 provided in Reference 6-13, Table 18, Table 6-27 as a simple screening assessment for this low 1735 probability scenario. The soil DCGLs are assumed to be bounding for concrete debris and the 1736 fill material which will be a combination of concrete and native sand. Applying the summation 1737 rule, and conservatively performing the calculation for each Basement separately, the excavation 1738 dose was calculated. The dose results from TSD 14-021, Revision 1, Tables 22 and 26 are 1739 reproduced in Table 6-29. average concrete concentrations were 0.1% and 0.6% of the soil 1740 DCGL for the Auxiliary Basement and SFP/Transfer Canal Basement, respectively.
1741 Table 6-29 Large Scale Industrial Excavation Alternate Scenario Dose SFP/ Crib Auxiliary Containment Transfer Turbine House/ WWTF (mrem/yr) (mrem/yr) Canal (mrem/yr) Forebay (mrem/yr)
(mrem/yr) (mrem/yr)
Concrete AF 6.66 2.65 10.72 2.37 7.51 0.64 Concrete No AF 8.57 3.90 20.02 2.83 9.96 1.43 Fill AF 4.24 2.52 16.77 2.71 3.17 0.40 Fill No AF 4.89 2.97 31.40 3.05 3.63 0.74 1742 The dose from the less likely but plausible industrial excavation scenario was calculated 1743 applying the AFs (interpolated) from Table 6-40 to the surface area covered by the excavated 1744 material assuming the material is spread over a one meter depth on the ground surface. However, 1745 the Table 6-40 AFs were calculated for the Resident Farmer scenario and may be slightly high 1746 for the Industrial Scenario due to elimination of the plant pathway. Therefore, the dose was also 1747 calculated without AFs to provide a maximum value.
1748 NUREG-1757 recommends that greater assurance be provided to demonstrate that a less likely 1749 but plausible land use is unlikely if the dose from the scenario is significant. Based on 1750 projected land use in the vicinity of the ZNPS, as discussed in section 6.5.3, a future use that 1751 includes the large-scale excavation of the massive, reinforced concrete Basement structures that 1752 range from 15 to 49 feet below grade is unlikely, particularly in the next 50 years. The 1753 maximum dose from all basements, for excavated fill and concrete, was 31.40 mrem/yr for the 1754 SFP/Transfer Canal assuming no AF adjustment. The dose for the SFP/Transfer Canal including 1755 an AF adjustment was 16.77 mrem/yr. If AFs were calculated for the Industrial Use scenario it 1756 would likely result in a dose less than 25 mrem/yr for the SFP/Transfer Canal but the additional 6-55
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1757 calculation was not merited given that the low dose values reported in Table 6-29 for the less 1758 likely but plausible large-scale excavation land use were not significant.
1759 1760 6.8. Soil Dose Assessment and DCGL 1761 Site-specific DCGLs were developed for residual radioactivity in surface and subsurface soil that 1762 represent the 10 CFR 20.1402 dose criterion of 25 mrem/yr. A DCGL was calculated for each 1763 ROC.
1764 Surface soil is defined as contamination contained in the first 0.15 m layer of soil. Subsurface 1765 soil is defined as a layer of soil beginning at the surface that extends beyond 0.15 m. The 1766 subsurface soil thickness is arbitrarily set to a 1 m depth. DCGLs are calculated for both the 1767 0.15 m and 1 m thicknesses. Both the surface and subsurface DCGLs assume a continuous 1768 source term layer from the ground surface downward. There are no expectations of encountering 1769 soil contamination in a geometry consisting of a clean surface layer of soil over a contaminated 1770 subsurface soil layer.
1771 6.8.1. Soil Source Term 1772 During the initial characterization of impacted soils at ZNPS, 888 surface soil samples and 1773 723 subsurface soil samples were taken and analyzed for plant-derived radionuclides. Cs-137 1774 was detected at concentrations greater than MDC in 212 samples and Co-60 was detected at 1775 concentrations greater than MDC in 42 samples. The majority of the positive Cs-137 samples 1776 were in the range of background concentrations and unlikely to be plant-derived activity. The 1777 highest concentration of Cs-137 detected was 3.4 pCi/g in surface soils in a Class 1 open land 1778 survey unit located next to Unit 1 Containment. The highest level of Cs-137 detected in a 1779 surface soil sample taken from a Class 2 or Class 3 open land survey unit was 1.1 pCi/g. The 1780 highest concentration of Co-60 detected in any surface soil sample taken was 0.7 pCi/g.
1781 For subsurface soil samples, Cs-137 was detected at concentrations greater than MDC in 1782 15 samples and Co-60 was detected at concentrations greater than MDC in one sample. The 1783 highest level of Cs-137 detected in a subsurface soil sample was 1.0 pCi/g and the one sample 1784 where Co-60 was positively detected had a concentration of 0.1 pCi/g. In addition, nine surface 1785 soil samples and one subsurface soil samples where gamma spectroscopy indicated the presence 1786 of Co-60 and/or Cs-137 were analyzed for all ROC, including HTD radionuclides. No other 1787 plant-derived radionuclides were positively identified by the HTD analyses.
1788 The results of surface and subsurface soil characterization in the impacted area of ZNPS indicate 1789 that there is minimal residual radioactivity in soil above background. However, the assessment 1790 of potential subsurface soil contamination is not complete at the time of this LTP submittal 1791 (Revision 0). Soil sampling in difficult to access areas such as under building foundations and 1792 surrounding buried structures has been deferred until access is more readily available. Based on 1793 the characterization survey results to date, ZSRP does not anticipate the presence of significant 1794 soil contamination in the areas remaining to be characterized.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1795 6.8.2. Soil Radionuclides of Concern, Insignificant Contributor Dose and Surrogate 1796 Ratio 1797 The radionuclides of concern for soil were determined in TSD 14-019 using the same process 1798 described in section 6.5.2 but replacing Basement DCGLs with soil DCGLs. There were very 1799 few positive soil sample results identified during characterization and the levels were insufficient 1800 to provide a meaningful evaluation of HTD radionuclides. Therefore, the radionuclide mixture 1801 for the Auxiliary Basement cores was applied to soil. for planning purposes. As described in 1802 LTP Chapter 5, section 5.1, the soil mixture will be reviewed as data is collected during 1803 continuing characterization and FSS. If levels of residual radioactivity are encountered in an 1804 open land survey unit that exceeds 10% of the 25 mrem/yr Dose Criterion (2.5 mrem/yr), then 1805 samples will be analyzed for HTD radionuclides. Note that the dose contribution from HTD 1806 radionuclides at ZNPS has been shown to be trivial based on characterization to date and is 1807 expected to be trivial at license termination. Gamma emitters are directly measured during the 1808 Final Status Survey (FSS).
1809 The 26 radionuclides in the initial suite of radionuclides, and the Auxiliary concrete mixture 1810 fractions listed in Table 6-2 were used to determine the The IC dose contributionpercentage for 1811 from soil was calculated using the Table 6-2 mixture which is considered the most representative 1812 available. As a cross-check of the Table 6-2 mixture, the IC dose was also calculated using a 1813 mixture comprised of the data from the 10 soil samples analyzed for the initial suite. The dose 1814 from individual samples was calculated in two ways; using the mean of the MDC values and 1815 using the mean of the insignificant contributors, using the methods described in TSD 14-1816 019.actual net results. Due to the fact that essentially all of the soil characterization results were 1817 non-detect, with the exception of Cs-137 at very low levels and generally in the range of 1818 background, a significant and unrealistic bias in the IC dose calculation results was introduced 1819 by the use of MDC values. To provide a more realistic evaluation of the IC dose, a separate 1820 calculation was performed using the mean of actual net results. The analysis of individual soil 1821 samples was not considered meaningful given that all of the results were less than MDC. Other 1822 than low level Cs-137, the only positive result in soil samples was Co-60 in one sample at a 1823 concentration of 0.24 pCi/g.
1824 The IC dose percentage for soil using the Table 6-2 mixture is provided in Table 6-30. The 1825 mixture and dose percentages for the ROC are also shown in Table 6-30. The mean IC dose and 1826 IC dose percentage from the two evaluations of the soil sample mixture are listed in Table 6-31.
1827 The IC dose percentage assuming the best estimate Table 6-2 mixture was 0.171% (Table 6-1828 30). The IC dose calculated using the results of the 10 soil samples analyzed for the initial suite 1829 and applying MDC values for all non-detect radionuclides (i.e., essentially all radionuclides) was 1830 9.9% (Table 6-31). The more realistic calculation of IC dose using the actual reported results 1831 from the 10 soil samples, as opposed to MDCs, resulted in an IC dose percentage of 1.96%
1832 (Table 6-31). The actual results better correspond to the fact that the underlying assumption for 1833 the MDC calculation is that the mean net result is zero when no activity is present.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1834 Table 6-306-19 Soil ROC Mixture and IC nsignificant Contributor Dose 1835 Percentage Using 1836 the Table 6-2 Best Estimate Mixture.
Percent Mixture Radionuclide Annual Percent Dose Co-60 0.91% 3.878%
Ni-63 23.48% 0.119%
Sr-90 0.05% 0.072%
Cs-134 0.01% 0.028%
Cs-137 74.60% 95.733%
Insignificant Contributor 0.95% 0.171%
Percent Total 100% 100%
1837 1838 1839 soil ROCs and insignificant contributor dose contribution is listed in Table 6-19. As seen in 1840 Table 6-19, the dose contribution of the insignificant contributor radionuclides removed 1841 from the initial suite is 0.171% of the total dose. The Table 6-31 Soil IC Dose and 1842 Dose Percentage using Soil Sample Results Data Used for Non-Detect IC Dose IC Dose Percentage mrem/yr (of 25 mrem/yr)
MDC Values 2.47 9.9%
Actual Reported Results 0.49 1.96%
1843 1844 The IC dose percentage for soil is considered to be between 0.17% and 1.96%. The 9.9% IC 1845 dose percentage is not considered representative of the actual site mixture due to MDC biasing 1846 issues. For example, it is very likely that the same MDC values would have been reported in the 1847 analysis of a soil sample from an offsite location, with the same calculation results. However, to 1848 ensure conservatism, an IC dose percentage of 10% will be used to adjust the ROC DCGLs for 1849 soil to conservatively account for the IC dose. The 10% (2.5 mrem/yr) value significantly 1850 exceeds the IC dose percentage calculated using the best estimate Table 6-2 mixture or the actual 1851 soil analytical results and provides a significant margin to account for uncertainty.
1852 1853 None of the 10 soil samples analyzed for the initial suite contained positive results for a HTD 1854 ROC, or any HTD radionuclide. Therefore, it is not technically feasible to develop radionuclide 6-58
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1855 ratios for use with the surrogate approach during FSS. The radionuclide ratios for Sr-90/Cs-137 1856 and Ni-63/Co-60 calculated for the Auxiliary Basement in section 6.5.2.4 will be used in the 1857 surrogate evaluations for soil.
1858 6.8.3. Soil Exposure Scenario and Critical Group 1859 The Resident Farmer exposure scenario and critical group as described in section 6.5.3 for the 1860 BFM also applies to the soil dose assessment. The Resident Farmer Scenario includes the 1861 following exposure pathways:
1862
- Direct exposure to external radiation 1863
- Inhalation dose from airborne radioactivity 1864
- Ingestion dose from the following pathways:
1865 - Plants grown with irrigation water from onsite well 1866 - Meat and milk from livestock consuming fodder from fields irrigated with onsite well 1867 water and consuming water from onsite well 1868 - Drinking water from onsite well 1869 - Soil ingestion 1870 6.9. Soil Computation Model - RESRAD v7.0 1871 RESRAD version 7.0 was used to calculate DCGLs for surface and subsurface soil.
1872 6.9.1. Parameter Selection 1873 The parameters selection process described in section 6.6.3.1 and summarized in Figure 6-10 1874 was used to select the RESRAD input parameters for soil. The vast majority of the behavioral, 1875 metabolic and physical parameters are the same as those developed for the BFM RESRAD 1876 modeling. However, the conceptual model for soil required changes to the following parameters:
1877
- Kd values for site soil (sand) were selected based on the review provided by Brookhaven 1878 National Laboratory in TSD 14-004 (see Table 6-3220),
1879
- Cover depth = 0, 1880
- Time Since Material Placement parameter set to zero, 1881
- No initial contamination penetrates the saturated zone, 1882
- An unsaturated zone is assumed to be present, and 1883
- Non-dispersion groundwater model used.
1884 1885 1886 6-59
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1887 Table 6-326-20 Distribution Coefficients for Surface and Subsurface Soil RESRAD 1888 Analysis Radionuclide Soil Kd (cm3/g)
Co-60 1161 Ni-63 62 Sr-90 2.3 Cs-134 615 Cs-137 615 1889 6.9.2. Uncertainty Analysis 1890 Parameter uncertainty analysis was performed following the process described in section 6.6.3.1.
1891 The parameters used for the uncertainty analysis of the surface and subsurface soil dose 1892 modeling are the same as were used for the BFM RESRAD uncertainty analysis, with the 1893 exception of contaminated zone thickness. A 0.15 m thickness is used for surface soil and 1.0 m 1894 thickness for subsurface soil. The unsaturated zone depth was also adjusted to ensure that the 1895 depth to the water table remains constant for both the 0.15 m and 1.0 m contaminated zone 1896 thicknesses.
1897 The RESRAD input parameters used for the uncertainty analysis of both surface and subsurface 1898 soil are provided in Attachment 3. Deterministic parameters were selected for behavioral, 1899 metabolic and Priority 3 physical parameters in accordance with the process in Figure 6-10. The 1900 majority of the Priority 1 and 2 physical parameters are assigned the parameter distributions from 1901 NUREG/CR-6697. Three site-specific Priority 1 and 2 physical parameters are assigned 1902 deterministic values in the uncertainty analysis including cover depth, precipitation, and well 1903 pumping rate (which does not have a recommended distribution in NUREG/CR-6697). The 1904 distribution coefficients were assigned either deterministic site-specific values based on the most 1905 conservative laboratory analysis of site soil as documented in TSD 14-004 or the distribution 1906 from NUREG/CR-6697 if site-specific data were not available. There are other site-specific 1907 parameters available, but these are included in the uncertainty analysis. The distributions from 1908 NUREG/CR-6697 were used to ensure that the appropriate level of justification is provided if 1909 one or more of these site-specific parameters are determined to be sensitive.
1910 The uncertainty analysis was conservatively run for all ROC individually to maximize the 1911 number of parameters deemed sensitive. A more realistic approach would apply the radionuclide 1912 mixture fractions for ZNPS which could reduce the sensitivity of total dose to some parameters 1913 for the low abundance radionuclides. In addition, parameter input rank correlations were not 1914 applied because this also maximizes variability and corresponding parameter sensitivity. Surface 1915 soil parameters that exhibited sensitivity to dose (i.e., with a lPRCCl result greater than 0.25) are 1916 listed in Table 6-3321. The PRCC values listed are the highest individual values from the three 1917 runs made in the RESRAD Uncertainty Analysis. Tables 6-34 and 6-35 provide the selected 75th 1918 or 25th percentile deterministic values for surface soil from the NUREG/CR-6697 distributions 1919 for the positively and negatively correlated parameters, respectively.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1920 Table 6-336-21 Surface Soil DCGL Uncertainty Analysis Results for 1921 Parameters 1922 with lPRCCl >0.25 PRCC Value Parameter Co-60 Cs-134 Cs-137 Ni-63 Sr-90 Depth of Soil Mixing Layer NS -0.30 -0.36 -0.56 NS Depth of Roots -0.30 -0.47 -0.53 -0.78 -0.90 External Gamma Shielding Factor 0.99 0.96 0.93 NS NS Density of Contaminated Zone 0.59 0.32 NS NS NS Plant Transfer Factor 0.34 0.57 0.63 0.86 0.96 Meat Transfer Factor 0.26 0.25 0.31 NS NS Milk Transfer Factor NS 0.25 0.31 0.88 0.36 1923 Table 6-346-22 Selected Deterministic Values for Surface Soil DCGL Sensitive 1924 Parameters from Table 6-21 That Are Radionuclide Independent Parameter Percentile Parameter Value Depth of Soil Mixing Layer 25th 0.15 Depth of Roots 25th 1.22m External Gamma Shielding Factor 75th 0.40 Density of Contaminated Zone 1.68 g/cm3 (site-specific 75th value of 1.8 g/cm3 used) 1925 Table 6-356-23 Deterministic Values for Surface Soil DCGL Sensitive Parameters 1926 from Table 6-21 that are Radionuclide Dependent Plant Transfer Factor Meat Transfer Factor Milk Transfer Factor Radionuclide 75 Percentile th 75 Percentile th 75th Percentile Co-60 0.15 0.058 NS Cs-134 0.078 0.065 0.014 Cs-137 0.078 0.065 0.014 Ni-63 0.092 NS 0.032 Sr-90 0.59 NS 0.0027 6-61
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1927 Subsurface soil parameters with a lPRCCl result greater than 0.25 are listed in and Table 6-36.
1928 Tables 6-37 and 6-38 provide the selected 75th or 25th percentile deterministic values for 1929 subsurface soil. The median of the NUREG/CR-6697 distributions was assigned to the Priority 1 1930 and 2 parameters that were not sensitive (i.e., not listed in Tables 6-3321 and 6-3624). The 1931 RESRAD Uncertainty Reports for each ROC are provided in TSD 14-010.
1932 Table 6-366-24 Subsurface Soil DCGL Uncertainty Analysis Results for 1933 Parameters with lPRCCl > 0.25 Parameter PRCC Value Co-60 Cs-134 Cs-137 Ni-63 Sr-90 Depth of Roots -0.45 -0.60 -0.69 -0.86 -0.93 External Gamma 0.97 0.90 0.84 NS NS Shielding Factor Plant Transfer Factor 0.67 0.83 0.88 0.96 0.98 Meat Transfer Factor 0.40 0.29 0.37 NS NS Milk Transfer Factor NS 0.35 0.45 0.91 0.44 1934 Table 6-376-25 Selected Deterministic Values for Subsurface Soil DCGL Sensitive 1935 Parameters from Table 6-28 that are Radionuclide Independent Parameter Percentile Parameter Value Depth of Roots 25th 1.22m External Gamma Shielding 75th 0.40 Factor 1936 Table 6-386-26 Deterministic Values for Subsurface Soil DCGL Sensitive Parameters 1937 from Table 6-28 that are Radionuclide Dependent Plant Transfer Factor Meat Transfer Factor Milk Transfer Factor Radionuclide 75th Percentile 75th Percentile 75th Percentile Co-60 0.15 0.058 NS Cs-134 0.078 0.065 0.014 Cs-137 0.078 0.065 0.014 Ni-63 0.092 NS 0.032 Sr-90 0.59 NS 0.0027 6-62
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1938 6.10. RESRAD Results and Soil DCGLs 1939 The surface and subsurface soil DCGLs were calculated using the deterministic parameter set 1940 provided in Attachment 4. The RESRAD Summary Reports are provided in TSD 14-010. The 1941 surface and subsurface soil DCGLs are provided in Table 6-3927. Note that the values reported 1942 in Table 6-3927 also include adjustment to account for the trivial 0.171% 10% dose contribution 1943 from removed insignificant contributors (see section 6.8.2Table 6-19) 1944 Table 6-396-27 Adjusted RESRAD Surface Soil and Subsurface Soil 1945 DCGLs 1946 (Adjusted for to Account for IC nsignificant Contributor Dose)
Surface Soil DCGL Subsurface Soil DCGL Radionuclide (pCi/g) (pCi/g)
Co-60 4.264.7 3.443.8 Cs-134 6.777.5 4.444.9 Cs-137 14.1815.7 7.758.5 Ni-63 3572.103988 763.02847 Sr-90 12.0914.3 1.661.8 1947 6.11. Soil Area Factors 1948 The RESRAD modeling for soil assumes a large source term area of 64,500 m2. Isolated areas 1949 of contamination that are smaller than 64,500 m2 will have a lower dose for a given 1950 concentration. The ratio of the dose from the full source term area to the dose from a smaller 1951 area is defined as the AF.
1952 ZionSolutions TSD 14-011, Soil Area Factors (Reference 6-30), calculates Area Factors (AF) 1953 for each ROC using RESRAD. The source area sizes ranged from 1.0 m2 up to the full source 1954 area of 64,500 m2. The AFs are relatively insignificant for areas greater than 100 m2 and in 1955 practice are very unlikely to be required for greater areas. The RESRAD parameter set in 1956 Attachment 4 was used in TSD 14-011 to generate the AFs by varying the source term areas in 1957 each run. The RESRAD Summary Reports are provided in TSD 14-011. The surface soil and 1958 subsurface soil AFs for areas up to 100 m2 are listed in Tables 6-4028 and 6-4129. A 1959 comprehensive list of AFs is provided in LTP Chapter 5, Table 5-7 and 5-8.
1960 6.12. Buried Piping Dose Assessment and DCGL 1961 Buried piping is defined as pipe that runs through soil.below ground pipe located outside of 1962 structures and basements. The dose assessment methods and resulting DCGLs for buried piping 1963 are described in detail in ZionSolutions TSD 14-015, Buried Pipe Dose Modeling & DCGLs 1964 (Reference 6-4). This section summarizes the methods and provides the resulting DCGLs for 1965 buried pipe.
1966 As discussed in section 6.14, the maximum dose from buried piping will be added to the 1967 maximum dose from the open land survey unit(s). The rationale for this approach is identical to 6-63
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1968 the standard process presented in MARSSIM for accounting for dose from elevated areas of 1969 residual radioactivity within an open land survey unit.
1970 Table 6-406-28 Surface Soil Area Factors Area Factors for Radionuclides of Concern Area (m2)
Cs-137 Co-60 Cs-134 Ni-63 Sr-90 1 1.50E+01 1.23E+01 1.33E+01 8.06E+03 8.90E+02 3 6.46E+00 5.24E+00 5.73E+00 2.73E+03 3.13E+02 10 3.06E+00 2.47E+00 2.72E+00 8.23E+02 1.03E+02 30 2.10E+00 1.68E+00 1.86E+00 2.75E+02 4.02E+01 100 1.62E+00 1.29E+00 1.44E+00 8.26E+01 1.64E+01 1971 Table 6-416-29 Subsurface Soil Area Factors Area Factors for Radionuclides of Concern Area (m2)
Cs-137 Co-60 Cs-134 Ni-63 Sr-90 1 2.04E+01 1.10E+01 1.52E+01 6.49E+03 1.50E+03 3 9.26E+00 4.91E+00 6.92E+00 2.17E+03 5.23E+02 10 4.48E+00 2.36E+00 3.35E+00 6.51E+02 1.64E+02 30 3.23E+00 1.70E+00 2.42E+00 2.17E+02 5.72E+01 100 2.59E+00 1.37E+00 1.95E+00 6.51E+01 1.76E+01 1972 6.12.1. Buried Pipe Source Term and Radionuclides of Concern 1973 Buried piping, with internal diameters ranging from one inch to 482 inches is expected to remain 1974 at the time of license termination. The Circulating Water Intake Pipesing, Service Water 1975 Headers, and Circulating Water Discharge Tunnels (and associated Discharge Tunnel Pipe 1976 located in the Turbine Building) are not considered buried pipe. The dose from residual 1977 radioactivity that may remain in the Intake Pipe and Discharge Tunnel se systems iis accounted 1978 for by adding the surface area (representing source term) measured inventory to the BFM source 1979 term in the to the applicable Basement in the DCGL calculation. The current list of buried 1980 piping expected to remain (as of the date of this LTP, Revision 10) is provided in TSD 14-016 1981 (Reference 6-3). and LTP Chapter 2, Table 2-27.
1982 The list of buried piping may be updated based on engineering reviews or changes in project 1983 plans although significant revisions are not expected. As discussed below, the Buried Pipe 1984 DCGL is based on the summation of the surface area of all pipe to ensure conservatism 1985 regardless of the pipe location. A significant revision to the buried pipe list is defined as a 1986 revision that increases the total surface area of buried pipe to a value greater than the 2153 m2 1987 assumed in the DCGL calculation. Decreasing the amount of Buried Pipe to remain, i.e.,
1988 removing more pipe than currently planned, would decrease the source term and corresponding 6-64
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 1989 dose. The DCGL becomes more conservative if less than 2153 m2 of pipe surface area remains 1990 and therefore no DCGL revision is necessary if additional pipe is removed.
1991 None of the listed buried piping was associated with systems involving reactor coolant. Based 1992 on process knowledge, the majority of piping is expected to contain minimal residual 1993 radioactivity at levels well below the DCGLs.
1994 To date, with the exception of some Turbine Basement drains, samples from piping systems have 1995 not been collected. Therefore, ZSRP is currently using the results of Auxiliary Basement 1996 concrete cores to represent the ROC and mixture for buried piping (see Table 6-3). Buried 1997 piping will be characterized as part of the continuing characterization program in accordance 1998 with LTP Chapter 2 section 2.5. and the results compared to the assumed radionuclide mixture.
1999 As discussed in LTP Chapter 5, section 5.1, if survey results indicate that the buried piping dose 2000 could exceed 10% of the 25 mrem/yr Dose Criterion, then samples will be analyzed for HTD 2001 radionuclides to confirm the mixture. If additional radionuclides other than those listed in 2002 Table 6-3 are found to be significant, then buried pipe DCGLs will be calculated for the 2003 additional radionuclides using the methods described in TSD 14-015.
2004 6.12.2. Buried Pipe Exposure Scenario and Critical Group 2005 The critical group for the buried piping dose assessment is the Resident Farmer.
2006 The buried pipe DCGL is determined for two scenarios; assuming that all pipe is excavated and 2007 assuming that all pipe remains in situ. Although unrealistic, for the purpose of the bounding 2008 modeling approach used, the dose from the two scenarios is summed to determine the Buried 2009 Pipe DCGL.
2010 The excavation scenario assumes that all buried pipe is excavated and all activity on the internal 2011 surfaces of the pipes instantly released and mixed with surface soil. The in situ scenario assumes 2012 that all of the buried piping remains in the as-left condition at the time of license termination 2013 and that all activity is instantly released to adjacent soil. Two separate in situ calculations were 2014 performed. The first assumes that all pipes are located at 1 m below the ground surface and the 2015 second assumes that all pipes are located in the saturated zone.Consistent with guidance in 2016 NUREG-1757, Appendix J regarding assessment of buried material, the exposure scenario 2017 includes two parts; 1) inadvertent intrusion due to house construction which results in the buried 2018 pipe being excavated and spread across the surface, and 2) dose from buried pipe remaining in 2019 situ. The buried piping DCGLs are based on the sum of the dose contribution from both 2020 intrusion and in situ.
2021 6.12.3. Buried Pipe RESRAD Model for Excavation Scenario 2022 The Excavation scenario assumes that all of the buried piping is excavated, brought to the 2023 surface and spread over a contiguous area equal to the internal surface area of the pipe. After 2024 being brought to the surface all of the activity on the internal surfaces of the pipe is assumed to 2025 instantly release and mix in a 0.15 m depth of surface soil.
2026 RESRAD modeling is used to determine the dose from excavated buried pipe in units of 2027 mrem/yr per pCi/g. The RESRAD parameters used are the same as those used for surface soil 2028 DCGLs (see Attachment 4) with the following exceptions:
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2029
- Area of Contaminated Zone 2153 m2 2030
- Length Parallel to Flow SFP/Transfer Canal 46 m 2031
- Cover Depth 0m 2032
- Unsaturated Zone Thickness 3.45 m 2033 The Area of Contaminated Zone parameter is equal to the total internal surface are of all buried 2034 pipe. The complete list of buried pipe and total surface internal surface area is provided in 2035 Reference 6-4, Attachment 1. The length parallel to flow is the square root of the contaminated 2036 area under a nominal assumption that the shape of the contaminated area is square. The bases for 2037 the remaining parameters are self-explanatory. Note that the buried pipe list was revised after the 2038 RESRAD runs were made (the de-icing lines were initially listed twice). The total internal 2039 surface area was reduced from 2153 m2 to 1539 m2. The reduced area results in lower dose to 2040 source ratios (DSRs) (mrem/yr per pCi/g) and therefore the DSRs using 2153 m2 were retained 2041 and used to calculate the Buried Pipe DCGLs which is conservative. Using the larger surface 2042 area also provides margin to account for the potential for additional buried pipe to be identified 2043 and added to the Reference 6-4, Attachment 1 list as decommissioning proceeds. Although not 2044 expected, if additional buried pipe is identified and added to the list, and the total surface area is 2045 increased but remains below the 2153 m2 assumed in the RESRAD model, the calculated buried 2046 pipe DCGLs would remain conservative. The area revision (and associated conservatism) also 2047 applies to the Insitu Saturated and Insitu Unsaturated scenarios RESRAD runs described in 2048 section 6.12.4.
2049 6.12.4. Buried Pipe RESRAD Model for Insitu Scenarios 2050 The Buried Pipe Insitu scenarios assume that the pipe remains in place. Two in situ geometries 2051 are evaluated. One scenario assumes that the buried pipe is in the unsaturated zone and a second 2052 scenario assumes that the pipe is in the saturated zone.
2053 For the Insitu Unsaturated Zone scenario, the pipes are assumed to be located 1 m below the 2054 ground surface. The ZSRP decommissioning approach calls for removal of all material, 2055 including piping, to 3 feet below grade. Note that portions of the storm drain system that will 2056 remain in place and functional after license termination are closer to the surface than 1 m but this 2057 minor exception is considered insignificant. Assuming that the pipe is within 1m of the surface 2058 allows the roots to penetrate the 0.15 m thick in situ source which maximizes dose.
2059 The RESRAD parameters used for the Buried Pipe Unsaturated Zone Insitu scenario are the 2060 same as those used for surface soil DCGLs (see Attachment 4) with the following exceptions:
2061
- Area of Contaminated Zone 2153 m2 2062
- Length Parallel to Flow 46 m 2063
- Cover Depth 1m 2064
- Unsaturated Zone Thickness 2.45 2065 The second in situ scenario evaluated assumed that all buried pipe is in the saturated zone. This 2066 scenario is intended to conservatively address the possibility that GW could possibly enter some 2067 portions of the buried piping.
2068 The RESRAD parameters used for the Buried Pipe Saturated Zone Insitu scenario are the same 2069 as those used for surface soil DCGLs (see Attachment 4) with the following exceptions:
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2070
- Area of Contaminated Zone 2153 m2 2071
- Length Parallel to Flow 46 m 2072
- Cover Depth 3.6 m 2073
- Unsaturated Zone Thickness 0m 2074
- Contaminated Fraction Below the Water Table 1 2075
- All Kds set to minimum site-specific value since dose is 100% from water pathways 2076 6.12.5. Buried Pipe Uncertainty Analysis 2077 An uncertainty analysis was performed for the three Buried Pipe dose scenarios to identify 2078 parameters that are sensitive in the Buried Pipe scenarios that were not identified as sensitive in 2079 the soil dose modeling uncertainty analysis. The process and criteria used to identify sensitive 2080 parameters and select conservative deterministic parameters were the same as that describe in 2081 Figure 6-10.
2082 The RESRAD parameters assigned for the uncertainty analysis are the same as those used for the 2083 soil uncertainty analysis listed in Attachment 7 with a few exceptions:
2084
- The Buried Pipe scenario parameters listed in section 6.12.4 were used as opposed to the 2085 corresponding soil parameters.
2086
- Kd distributions were included to represent the range of site-specific sand Kd values 2087 determined by laboratory analysis 2088
- To allow the dose from plant ingestion to vary with contaminated zone area, the two plant 2089 ingestion rate parameters were doubled to account for the fact that RESRAD 2090 automatically divides the entered ingestion rates by a factor of 2 when a value of -1 is 2091 used for the Contaminated Fraction of Plant Food parameter. The modified parameters 2092 are:
2093 o Fruits, non-leafy vegetables, grain consumption (kg/y) = 224 2094 o Leafy vegetable consumption (kg/y) = 42.8 2095 The only parameters that required change as a result of the uncertainty analysis were the 2096 Saturated Zone Hydraulic Gradient for the Insitu Saturated scenario and the Depth of Roots for 2097 the Insitu Unsaturated scenario. All of the remaining parameters identified as sensitive in 2098 Reference 6-4, Table 1 were already identified as sensitive, with the same correlation, in the soil 2099 DCGL sensitivity analyses. The corresponding parameters, either 25th or 75th percentile, were 2100 included in the baseline surface soil DCGL deterministic parameter sets used for the Buried Pipe 2101 RESRAD runs.
2102 The sensitivity of the assumed source term thickness required a separate analysis. The buried 2103 pipe scenarios assume that residual radioactivity is released from the pipes into adjacent soil. The 2104 thickness of soil into which the released activity was assumed to mix was 0.15 m which is 2105 considered the minimum reasonable mixing depth, particularly for the excavation scenario. As 2106 the Thickness of Contaminated Zone parameter is increased, assuming a unit concentration for 2107 all radionuclides, the dose increases. However, as the contaminated zone thickness increases the 2108 source term concentration decreases as an inverse linear function of the mixing depth. To 2109 determine the effect of these conflicting effects of increasing the Thickness of Contaminated 2110 Zone a separate sensitivity analysis was performed that accounts for both effects for source term 2111 thicknesses of 0.15 m and 1.0 m.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2112 Reference 6-4, Attachment 3 provides the results of the sensitivity analysis. Note that for all 2113 scenarios and all radionuclides except Sr-90 increasing the Thickness of Contaminated Zone 2114 either has no effect on dose (indicated by a value of 1 in the column labeled DSR Ratio*Source 2115 Term Decrease in the Reference 6-4, Attachment 3 Tables) or causes the dose to decrease 2116 (indicated by a fraction in the column labeled DSR Ratio*Source Term Decrease in Reference 2117 6-4, Attachment 3 Tables). The one exception, i.e., Sr-90, showed an 8% increase in dose at a 1 2118 m source term depth for the Insitu Saturated scenario and a 13% increase at 1 m depth for the 2119 Excavation Scenario.
2120 For the Insitu Saturated Scenario, increasing the source term thickness had no effect on dose for 2121 any radionuclides other than Sr-90. Note that the actual dose impact from the slightly increased 2122 Sr-90 dose for a 1 m thick source, as opposed to 0.15 m, is much lower than the values calculated 2123 individually for Sr-90 when the mixture percentages are considered. As shown in LTP Chapter 5, 2124 Table 5-2, the Auxiliary Basement mixture fraction (which is assumed to apply to buried pipe) 2125 for Cs-137 is 75.32% while the mixture fraction for Sr-90 is 0.05%. Therefore, the actual 2126 fractional dose attributable to the 8% and 20% increased values can be approximated as the ratio 2127 of percentages times the percentage increase, i.e., 1.08*0.05/75.32 and 1.13 *0.05/75.32, or 2128 0.07% and 0.08% of the final compliance dose which is insignificant.
2129 For the excavation scenario, there are conflicting results for Sr-90 and the gamma emitters.
2130 While the Sr-90 dose shows an increase of 13% for the 1 m depth the Cs-137 dose decreases by 2131 79%. When the mixture fractions are considered it is clear that the decrease in Cs-137 dose at 1 2132 m source term depth would be orders of magnitude greater than the slight Sr-90 increase which 2133 would result in a non-conservative dose calculation.
2134 In conclusion, the Thickness of Contaminated Zone parameter was set to 0.15 for all scenarios.
2135 However, to account for the indicated dose increase for Sr-90 at 1 m depth DSRs for Sr-90 were 2136 increased by factors of 1.08 and 1.13 for the Insitu Saturated and Excavation scenarios, 2137 respectively.
2138 6.12.6. Buried Pipe RESRAD Results 2139 Three RESRAD runs were performed for Buried Pipe; Excavation Scenario, Insitu Unsaturated 2140 Scenario, and Insitu Saturated Scenario (Reference 6-4). The RESRAD DSR results are 2141 summarized in Table 6-42.
2142 Table 6-42 RESRAD DSR Results for Buried Pipe Dose Assessment 2143 to Support DCGL Development Excavation Insitu Unsaturated Insitu Saturated Radionuclide (mrem/yr per pCi/g) (mrem/yr per pCi/g) (mrem/yr per pCi/g)
Co-60 4.975E+00 7.298E-02 5.710E-04 Cs-134 2.836E+00 1.070E-01 2.881E-03 Cs-137 1.238E+00 8.491E-02 2.287E-03 Ni-63 1.445E-03 1.285E-03 2.745E-04 6-68
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Sr-90 (1) 1.489E+00 1.384E+00 1.480E+00 2144 (1) The Sr-90 DSRs for Excavation and Insitu Saturated were multiplied by factors of 1.13 and 1.08, 2145 respectively, to adjust for potentially higher dose from thicker source terms (Reference 6-3) 2146 Excavation Scenario 2147 The excavation scenario assumes that a 10 m by 20 m (200 m2) house with a three meters deep 2148 basement is excavated by the Resident Farmer. During excavation, a 20 m length of pipe is 2149 assumed to be brought to the surface. Each of the various diameters to remain was evaluated.
2150 The NUREG-1757, Appendix J guidance states that given a Resident Farmer scenario, it should 2151 be appropriate to use the arithmetic average of the radionuclide concentration in the analysis, 2152 including any interspersing clean soil. The buried piping at ZNPS is a minimum of 1 m below 2153 grade. The ZSRP excavation scenario is more conservative than recommended in NUREG-1757 2154 in that no mixing is assumed to occur between residual radioactivity in the buried pipe, the 1 m 2155 of clean soil overburden, and interspersing clean soil during excavation.
2156 The buried pipe excavation scenario and conceptual model can be summarized as follows:
2157 The structural integrity of the buried piping is assumed to completely degrade in year zero, 2158 As a result of degradation, the activity internal to the buried piping is uniformly dispersed in a 2159 volume of soil equal to the internal volume of the pipe, 2160 The volume of the degraded piping/soil mix that is equal to the internal volume of the piping, 2161 assuming a length of 20 m, is excavated onto the surface soil and spread on the surface at a 2162 0.15 m thickness, and 2163 The Resident Farmer is exposed to the excavated soil.
2164 A key component of the buried piping excavation dose assessment conceptual model (and 2165 corresponding DCGL determination) is that the Resident Farmer is exposed to only a small area 2166 of contaminated soil after excavation and spreading. The size of the area is a function of the pipe 2167 diameter with the very small diameter pipes representing very small volumes and exposure areas 2168 after excavation. An AF approach is directly analogous to the process described for soil in 2169 section 6.11 and is used to determine the dose from the excavated and spread buried piping 2170 source term.
2171 In Situ Buried Piping Scenario 2172 The buried piping excavation scenario is assumed to include a small fraction of the total buried 2173 piping. The in situ scenario calculates the dose from the buried piping remaining in the ground.
2174 A number of the buried pipes are associated with systems that have a very low or negligible 2175 potential for being contaminated. The in situ scenario source term includes the inventory of 2176 those piping systems having a potential for contamination. Each pipe is assumed to be 2177 contaminated at the maximum DCGL calculated for the given pipe diameter. The source term is 2178 calculated over the estimated length of the pipe. See LTP Chapter 2, Table 2.27 for a 2179 comprehensive list of diameters and lengths of buried piping to remain.
2180 The total volume and inventory in all potentially contaminated piping was very conservatively 2181 assumed to be in one contiguous location, at a depth of 1 m below the ground surface, with no 2182 consideration of interspersing soil between pipes.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2183 Buried Piping Dose Assessment and DCGL Computational Method 2184 Detailed descriptions of the methods and calculations for the buried piping dose assessment and 2185 DCGL determination are provided in TSD 14-015. Each step in the dose assessment process is 2186 listed below assuming a given pipe diameter. The same process is followed in TSD 14-015 for 2187 each pipe diameter to determine the diameter-specific buried piping DCGLs.
2188 Buried Pipe Excavation Dose Calculation 2189 The dose calculation for the buried pipe excavation scenario involves a series of steps. The 2190 calculation sequence is summarized below:
2191 Calculate the internal volume for the buried pipe diameter assuming a 20 m length, 2192 Calculate the total allowable inventory in the volume calculated in Step 1, assuming uniform 2193 contamination levels at the surface soil DCGL concentrations, 2194 Calculate the internal surface area in the 20 m length of piping, 2195 Divide the total inventory calculated in Step 2 by the total internal surface area from Step 3 to 2196 determine corresponding surface activity levels in units of pCi/cm2, 2197 Convert the surface activity levels in Step 4 to units of dpm/100 cm2, 2198 Assume the pipe is excavated and the volume calculated in Step 1 is spread over a 0.15 m 2199 thickness on the surface. Calculate the corresponding spread area in units of m2.
2200 Calculate the subsurface soil AF corresponding to the spread area calculated in Step 6, 2201 Multiply the AF by the surface activity levels from Step 5, 2202 The result from Step 8 is the Buried Piping Excavation DCGL for a given diameter pipe.
2203 TSD 14-015 calculates the Initial DCGLs for each ROC and each diameter of buried pipe to 2204 remain. The minimum Initial DCGL values were found in 12 or 42 inch pipes, depending on the 2205 radionuclide. For conservatism, and ease of implementation, the lowest Initial DCGL values for 2206 each ROC were applied to all diameter pipes. See Table 6-30.
2207 Table 6-30 Buried Piping Initial DCGLs (Excavation Scenario only)
Radionuclide Buried Pipe DCGL ( dpm per 100 cm2)
Co-60 3.60E+04 Cs-134 6.33E+04 Cs-137 1.50E+05 Ni-63 3.06E+09 Sr-90 2.22E+06 2208 Buried Piping In Situ Dose Calculation 6-70
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2209 The second part of the buried piping DCGL calculation is the adjustment of the Initial DCGL 2210 which is based on excavation to account for the buried piping source term to remain in situ. The 2211 calculation details are provided in TSD 14-015 and summarized below. The adjustment factor is 2212 the ratio of 25 mrem/yr to the sum of 25 mrem/yr plus the in situ dose.
2213 The maximum inventory for Co-60, Cs-134, Cs-137, Ni-63 and Sr-90 associated with each 2214 section of piping that could remain in situ was calculated using the maximum allowable buried 2215 Piping Initial DCGLs at their respective diameters. The diameter-specific Initial DCGLs are all 2216 higher than or equal to the values listed in Table 6-30. This approach results in the most 2217 conservative, i.e., highest, source term for the in situ assessment.
2218 The scenario assumes that all the remaining potentially contaminated buried piping is 2219 conservatively located at one meter below the soil surface with a 1.0 m cover of clean native soil.
2220 The estimated total volume of potentially contaminated buried piping projected to remain is 2221 9.6 m3. It is conservatively assumed that all the piping is then located in a single contaminated 2222 zone with a 9.6 m2 area and a thickness of 1.0 m with no consideration of mixing with 2223 interspersing soil. The total inventory was assumed to be uniformly distributed within the 9.6 m3 2224 volume to generate a source term in units of pCi/g.
2225 RESRAD v7 was used to perform the dose assessment. The parameter set used to calculate the 2226 surface soil DCGL (see Attachment 4) was applied with source term geometry adjustments to be 2227 consistent with the scenario. In addition, the unsaturated zone depth was changed to 1.6 m and 2228 the length parallel to flow to 3.5 m to be consistent with the depth and area of the contaminated 2229 zone. In addition, an uncertainty analysis for this geometry indicated that the root depth was 2230 positivity correlated so the 75th percentile root depth of 3.05 m was used. The RESRAD output 2231 report for the buried piping in situ assessment is provided in TSD 14-015. The results of the in 2232 situ buried pipe assessment are provided in Table 6.31.
2233 6.12.3.6.12.7. Buried Piping DCGL 2234 As discussed above, the source term for the in situ buried piping dose assessment was based on 2235 the inventory that would be present if the buried piping surfaces contained residual radioactivity 2236 at concentrations equal to the DCGLs for the excavation scenario. The source terms and 2237 corresponding doses from the excavation and in situ scenarios occur at the same time and 2238 therefore must be summed to determine the total buried piping dose. To account for the in situ 2239 Table 6-31 In Situ Buried Piping RESRAD Results Assuming Uniform Pipe 2240 Contamination at the Maximum Excavation Initial DCGLs RESRAD Dose/Source Buried Piping In Situ Buried Buried Piping Nuclid Ratio Concentration Pipe Dose DCGL e Adjustment (mrem/yr per (pCi/g) (mrem/yr) Factor pCi/g)
Co-60 8.309E-04 1.33E+01 1.105E-02 1.00E+00 Cs-134 1.273E-03 2.79E+01 3.552E-02 9.99E-01 Cs-137 1.011E-03 6.61E+01 6.683E-02 9.97E-01 6-71
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Ni-63 1.527E-05 5.81E+06 8.872E+01 2.20E-01 Sr-90 2.815E-02 4.76E+03 1.339E+02 1.57E-01 2241 The Buried Pipe DCGL is determined by first calculating the pCi/g concentration in the 0.15 m 2242 soil mixing layer that corresponds to a unit concentration, 1 dpm/100 cm2, on the pipe surface.
2243 The second input to the DCGL calculation is the sum of the DSR for Excavation and the 2244 maximum DSR for the Insitu Scenarios. As seen in Table 6-43, the maximum Insitu DSR is from 2245 the Unsaturated Scenario for all radionuclides except Sr-90. Therefore, the DSR summation used 2246 in the Buried Pipe DCGL calculation is comprised of the Excavation and Insitu Unsaturated 2247 Scenario DSRs for all radionuclides except Sr-90 which is based on the summation of the 2248 Excavation and Insitu Saturated Scenario DSRs. The summed DSRs are shown in Table 6-43.
2249 Table 6-43 Maximum Summed RESRAD DSRs from 2250 Excavation and Insitu Scenarios Maximum Summed DSR Radionuclide Excavation + Insitu (mrem/yr per pCi/g)
Co-60 5.048E+00 Cs-134 2.943E+00 Cs-137 1.323E+00 Ni-63 2.730E-03 Sr-90 2.969E+00 2251 2252 The dpm/100 cm2 per pCi/g conversion factor is used with the maximum summation DSR in 2253 Table 6-43 to calculate the Buried Pipe DCGL as shown in Equation 6-8.
2254 Equation 6-8 2255 1 100 2 2256 = 25 2257 2258 where:
2259 BP DCGL = Buried Pipe DCGL (dpm/100 cm2) 2260 Max Summed DSR = Maximum Summed DSR values from Table 6-43 (pCi/g per mrem/yr) 2261 (dpm/100 cm2)/pCi/g = dpm/100 cm2 in pipe per pCi/g in soil 2262 2263 The calculation of Buried Pipe DCGLs is provided in Reference 6-4, Attachment 2. Table 6-44 2264 provides the resulting Buried Pipe DCGLs.
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ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2265 scenario dose, an adjustment factor was calculated by adding the in situ dose in Table 6.31, 2266 column 4, to the 25 mrem/yr dose attributable to the buried pipe excavation scenario alone (at the 2267 DCGL level), and then dividing the sum by 25 mrem/yr. The adjustment factors are provided in 2268 Table 6-31, column 5. The Initial DCGLs listed in Table 6.30 were adjusted to account for the in 2269 situ dose by multiplying the Initial DCGL by the adjustment factor listed in Table 6.31, 2270 column 5. The final, adjusted Buried Piping DCGLs are listed in Table 6-32.
2271 A final check calculation was performed in TSD 14-021 to ensure that the ROC concentrations 2272 were below the soil DCGLs when excavated and mixed with the total basement excavation 2273 volume of 600 m3. The inventory was assuming to be equal to the piping inventory calculated in 2274 the in situ assessment in section 6.12.3. All of the excavated, mixed concentrations were below 2275 the soil DCGLs except Ni-63 which was 5.15 times higher. The Ni-63 buried piping DCGL was 2276 further adjusted lower by a factor of 0.194 (1/5.15) to ensure that the excavated, mixed 2277 concentration was equal to the soil DCGL.
2278 Table 6-446-32 Buried Piping DCGLs (Not Adjusted for IC Dose)
Buried Pipe DCGL (
Radionuclide dpm per 100 cm2)
Co-60 2.94E+043.6E+04 Cs-134 5.04E+046.33E+04 Cs-137 1.12E+051.50E+05 Ni-63 5.44E+071.31E+08 Sr-90 5.00E+043.49E+05 2279 2280 6.12.8. Adjustment for Dose from Insignificant Contributors 2281 The buried pipe DCGLs must be adjusted to account for the radionuclides in the initial suite that 2282 were removed due to insignificant dose contribution. The Excavation scenario is closely related 2283 to the soil DCGL scenario. The Buried Pipe Insitu scenarios, particularly the Insitu Saturated, 2284 have a greater potential groundwater dose contribution than the soil DCGL scenario and are 2285 more closely related to the BFM scenarios. The activity in buried pipes originate in one of the 2286 basements and the activity is assumed to mix with basements as well as mix with soil.
2287 Therefore, the insignificant dose contribution percentage assigned for the Buried Pipe DCGL 2288 adjustment was the maximum for either soil or the BFM. The maximum IC dose percentage was 2289 10% for both soil and the BFM (Containment) and was the value used for Buried Pipe DCGL 2290 adjustment.
2291 The Adjusted Buried Pipe DCGLs are provided in Table 6-45.
2292 Table 6-45 Adjusted Buried Pipe DCGLs (Adjusted for IC Dose)
Adjusted Radionuclide Buried Pipe DCGL (dpm/100 cm2)
Co-60 2.64E+04 6-73
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Cs-134 4.54E+04 Cs-137 1.01E+05 Ni-63 4.89E+07 Sr-90 4.50E+04 2293 6.13. Embedded Piping DCGLand Penetrations 2294 Embedded piping is defined as piping that runs vertically in a concrete wall or horizontally in a 2295 concrete floor. The residual radioactivity in embedded piping to remain has no release pathway 2296 other than into the Basement(s) where the piping terminates. Each embedded pipe run is treated 2297 as a separate survey unit within the basement that the embedded pipe is located and the DCGL 2298 calculated accordingly.
2299 The embedded pipe to remain in the End State is identified and quantified in TSD 14-016. The 2300 embedded pipe survey units are listed in Table 6-46 along with the total internal survey area of 2301 the pipes in the survey unit. The IC-sump embedded pipe is very limited with a total surface area 2302 of 1.05 m2 each for Unit 1 and Unit 2. To provide a reasonable maximum value for the DCGL a 2303 nominal area of 100 m2 was assumed for the surface area of IC sump embedded pipe survey unit.
2304 The U2 Steam Tunnel surface area was slightly lower than the U1 area (46.88 m2 versus 46.39 2305 m2). For simplicity, the higher, more conservative, area was applied to both Steam Tunnel Floor 2306 Drain DCGL calculations.
2307 2308 Table 6-46 Embedded Pipe Survey Unit Surface Areas EP SU Surface Area Embedded Pipe (m2)
Auxiliary Floor Drains 299.41 Turbine Floor Drains 302.43 U1 Containment IC-Sump Drain 1.05 (100) (1)
U2 Containment IC-Sump Drain 1.05 (100) (1)
U1 Steam Tunnel Floor Drain 46.88(2)
U2 Steam Tunnel Floor Drain 46.88(2)
U1 Tendon Tunnel Floor Drain 51.41 U2 Tendon Tunnel Floor Drain 51.41 2309 (1) The total surface area of unit 1 and unit 2 IC Sump Drains are 1.05 m each. To provide a reasonable maximum 2
2310 value for the DCGL a nominal area of 100 m2 was assumed for the DCGL calculation.
2311 (2) Higher surface area applied to both U1 and U2 Steam Tunnel Floor Drains. U2 area is 46.39 m2.
2312 DCGLs were calculated for each of the embedded pipe survey units using Equation 6-9.
2313 Equation 6-9 6-74
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 25 1 2314 (, ) = 109 2315 2316 Where:
2317 DCGLEP (b,i) = Embedded Pipe DCGL for radionuclide (i) in basement (b) 2318 (pCi/m2) 2319 BFM DF (b,i) = Summation of Basement Fill Model Dose Factors for 2320 Groundwater and Drilling Spoils scenarios for radionuclide (i) in 2321 basement (b) (mrem/yr per mCi) 2322 25 = 25 mrem/yr release criterion 2323 EP SU Area = Total internal surface area of all embedded pipe in the survey 2324 unit (m2) 2325 1E+09 = conversion factor of 1E+09 pCi/mCi 2326 IC Dose Factor = Insignificant contributor dose adjustment factor equal to 0.90 for 2327 Tendon Tunnel and IC-Sump embedded pipe and 0.95 for 2328 remaining embedded pipe (see section 6.5.2.3) 2329 The embedded pipe DCGL calculations are provided in Reference 13. Note that the Tendon 2330 Tunnel Floor drains are included in both the Containment and Turbine Basement compliance 2331 demonstrations (see LTP Rev 1, Chapter 5, Table 5-15). The embedded pipe DCGL was 2332 therefore calculated for both basements. The DCGLs calculated using the Containment Basement 2333 Dose Factors in Equation 6-9 were lower than using the Turbine Basement Dose Factors and 2334 were therefore assigned as the Tendon Tunnel floor drain DCGLs. The embedded pipe DCGLs 2335 are provided in Table 6-47.
2336 Table 6-47 Embedded Pipe DCGLEP (Adjusted for Insignificant Contributor Dose)
Radionuclide Auxiliary Turbine IC-Sump Steam Tunnel Tendon Tunnel Floor Drain Floor Drain Drain Floor Drain Floor Drains U1 and U2 U1 and U2 U1 and U2 (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2) (pCi/m2)
Co-60 7.33E+09 6.31E+09 5.47E+09 1.31E+10 1.06E+10 Cs-134 5.10E+09 1.43E+09 1.05E+09 2.96E+09 2.04E+09 Cs-137 2.68E+09 1.89E+09 1.37E+09 3.92E+09 2.67E+09 Ni-63 2.78E+11 1.96E+11 1.40E+11 4.06E+11 2.48E+10 Sr-90 2.41E+08 6.94E+07 4.98E+07 1.44E+08 2.16E+10 H-3 NA NA 8.28E+09 NA 1.61E+10 Eu-152 NA NA 1.28E+10 NA 2.72E+11 Eu-154 NA NA 1.11E+10 NA 9.70E+07 2337 2338 2339 6-75
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2340 2341 2342 6.14. Penetration DCGL 2343 A penetration is defined as a pipe (or remaining pipe sleeve, if the pipe is removed, or concrete, 2344 if the pipe and pipe sleeve are removed) that runs through a concrete wall and/or floor, between 2345 two buildings, and is open at the wall or floor surface of each building. A penetration could also 2346 be a pipe that runs through a concrete wall and/or floor and opens to a building on one end and 2347 the outside ground on the other end.
2348 A penetration survey unit is defined for each basement. The direction that the residual 2349 radioactivity may migrate, i.e., into which basement, cannot be predicted with certainty.
2350 Therefore, a given penetration that begins in one basement and ends in another will be included 2351 in the survey units for both basements. The residual radioactivity in the penetration is assumed to 2352 release to both basements simultaneously.
2353 The penetration DCGL (DCGLPN) is calculated in the same manner as embedded pipe using 2354 Equation 6-9 but replacing the embedded pipe survey unit surface area with the penetration 2355 survey unit surface area. The penetration survey units are defined in TSD 14-016 including the 2356 total area of each penetration survey unit as listed in Table 6-48.
2357 An additional adjustment is required for the calculation of the DCGLPN for the Auxiliary 2358 Basement penetration survey unit. The release of residual radioactivity from the Auxiliary 2359 basement concrete assumes diffusion release. In most cases the remaining penetrations will be 2360 either the remaining pipe or steel pipe sleeve after a pipe is removed. Because the residual 2361 radioactivity is not contained at depth in concrete, the assumption of diffusion release through 2362 concrete is not applicable and instant release is conservatively assumed for the penetrations. As 2363 seen in Equation 6-9, the penetration DCGL calculation uses the BFM Dose Factors, which in 2364 the case of the Auxiliary basement are based on an assumption of diffusion release.
2365 Table 6-48 Penetration Survey Unit Surface Areas Penetration Survey Unit Surface Area Embedded Pipe (m2)
Auxiliary Basement 948.75 Containment Basement 242.36 Turbine Basement 1081.14 SFP/Transfer Canal 337.45 Crib House/Forebay 1.14 WWTF 0.89 2366 An adjustment is therefore required to account for the higher maximum release rate under an 2367 instant release assumption as compared to diffusion release. The correction factor was calculated 2368 in TSD14-009, Revision 3, Attachment G, where the maximum concentration in the Auxiliary 6-76
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2369 Basement under an instant release assumption was compared to the maximum concentration 2370 using a diffusion release assumption. The adjustment factor was calculated as the ratio of 2371 maximum instant release to maximum diffusion release. The results from TSD 14-009, Revision 2372 3, Attachment G are reproduced in Table 6-49.
2373 Table 6-49 Ratio of Instant Release Maximum to Diffusion 2374 Release Maximum for Auxiliary Basement Radionuclide Auxiliary Floor Drain Co-60 26.23 Cs-134 4.91 Cs-137 1.37 Ni-63 14.96 Sr-90 19.1 H-3 1.01 Ni-63 1.29 Sr-90 3.15 2375 The DCGLPN for the Auxiliary Basement penetration survey unit is then calculated using 2376 Equation 6-10 which is the same as Equation 6-9 with an additional term, i.e., RatioID, to 2377 account for instant release from Auxiliary Basement penetration survey unit to the Auxiliary 2378 basement.
2379 Equation 6-10 25 1 2380 (, ) = 109
( () + ())
2381 Where:
2382 DCGLEP (A,i) = Embedded Pipe DCGL for radionuclide (i) in Auxiliary 2383 basement (A) (pCi/m2) 2384 BFM DFgw (i) = Basement Fill Model Groundwater Dose Factor for radionuclide 2385 (i) in Auxiliary basement (b) (mrem/yr per mCi) 2386 BFM DFds (i) = Basement Fill Model Drilling Spoils Dose Factor for 2387 radionuclide (i) in Auxiliary basement (b) (mrem/yr per mCi) 2388 RatioID = ratio of instant release maximum concentration to diffusion 2389 release concentration 2390 25 = 25 mrem/yr release criterion 2391 PEN SU Area = Total internal surface area of Auxiliary Basement penetration 2392 survey unit (m2) 2393 1E+09 = conversion factor of 1E+09 pCi/mCi 2394 IC Dose Factor = Insignificant contributor dose adjustment factor equal to 0.90 for 2395 Containment and 0.95 for all other basements (see LTP Chapter 6 2396 section 6.8.2) 6-77
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2397 The penetration DCGLPN are calculated in Reference 13. The DCGLPN values are provided in 2398 Table 6-50. Note that the DCGLPN for the Crib House/Forebay and WWTF are listed as not 2399 applicable due the very small surface areas of the few penetrations present (1.14 m2 and 0.89 2400 m2). The Crib House/Forebay and WWTF penetrations DCGLs are set equal to the wall/floor 2401 surface DCGL and included with the Crib House/Forebay and WWTF surface survey units.
2402 Table 6-50 Adjusted Penetration DCGLPN (adjusted for insignificant contributor dose)
SFP/ Crib Transfer House/
Nuclide Auxiliary Containment Canal(1) Turbine Forebay1 WWTF (pCi/m )2 (pCi/m )2 (pCi/m )2 (pCi/m )2 (pCi/m )
2 (pCi/m2)
Co-60 8.82E+07 2.26E+09 4.45E+08 1.76E+09 NA NA Cs-134 3.28E+08 4.32E+08 7.48E+08 4.00E+08 NA NA Cs-137 6.17E+08 5.66E+08 1.46E+09 5.29E+08 NA NA Eu-152 3.29E+08 5.26E+09 9.44E+08 4.06E+09 NA NA Eu-154 2.33E+08 4.58E+09 8.53E+08 3.58E+09 NA NA H-3 3.99E+09 3.42E+09 4.84E+16 3.23E+09 NA NA Ni-63 6.79E+10 5.78E+10 1.86E+14 5.48E+10 NA NA Sr-90 2.41E+07 2.06E+07 9.26E+10 1.94E+07 NA NA 2403 (1) The DCGLPN for the Crib House/Forebay and WWTF are listed as not applicable due the very small 2404 surface area of the penetrations present. These penetrations are included with the Crib House/Forebay and WWTF 2405 surface survey units and the surface DCGLB will apply.
2406 2407 6.14.6.15. Existing Groundwater Dose 2408 As previously stated, no groundwater contamination has been identified by groundwater 2409 monitoring performed as of the date of this LTP (Revision 10) to date and is not expected to be 2410 present at the time of license termination. However, if groundwater contamination is identified 2411 during decommissioning, the dose will be calculated using the BFM Groundwater Exposure 2412 Factors in Table 6-185. Table 6-185 was developed as a part of the BFM, but the BFM 2413 Groundwater Exposure Factors presented in Table 6-185 are fully applicable to any groundwater 2414 contamination, regardless of the location.
2415 6.16. Clean Concrete Fill 2416 ZSRP will demonstrate that all concrete designated as backfill material in basements is clean 2417 through the Unconditional Release Survey (URS) program at Zion presented in ZionSolutions 2418 procedure ZS-LT-400-001-001, Unconditional Release of Materials, Equipment and Secondary 2419 Structures. Materials unconditionally released from Zion, regardless of their point of origin on 2420 the site, have been verified to contain no detectable plant-derived radioactivity and are free to be 2421 used and relocated anywhere offsite without tracking, controls, or dose considerations.
2422 Although the concrete debris to remain onsite and used as clean fill can be viewed as having a no 2423 dose impact, a dose value will be assigned for the purpose of demonstrating compliance with 10 2424 CFR 20.1402 in the same manner as other materials to remain at license termination that are 6-78
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2425 surveyed and found to not contain detectable activity. The detection limit used for the dose 2426 calculation is conservatively assumed to be the 5,000 dpm/100 cm2 value in I&E Circular 81-07.
2427 Actual detection limits in the unconditional release program are lower than this value.
2428 The vast majority of clean concrete fill to be used will come from five buildings; Containment, 2429 Turbine, Crib House/Forebay, Service Building and Interim Waste Storage Facility. Because the 2430 concrete will be from both Containment and other structures the dose calculation was performed 2431 using both the Containment and Auxiliary ROC mixtures. The dose was essentially the same for 2432 both mixtures but the dose with the Containment mixture was slightly higher (with trivial 2433 exception of WWTF). Consistent with the bounding approach used for the clean concrete 2434 assessment, the Containment mixture was applied to all concrete. In addition, when applying the 2435 ROC mixture, the 5,000 dpm/100 cm2 maximum detection limit was assumed to be 100% Cs-2436 137. The remaining radionuclide concentrations were added to the Cs-137 concentration at their 2437 respective ratios to Cs-137.
2438 The dose values are calculated separately for each basement assuming that the entire basement 2439 void is filled with concrete only. This conservatively includes the top three feet of fill which will 2440 be soil for all basements and not concrete. Details regarding the calculation are provided in 2441 Reference 13, section 8. The total dose results for each basement, including all ROC, are 2442 provided in Table 6-51. The dose values in Table 6-51 will be added to any basement where 2443 concrete fill is used regardless of the volume of concrete fill used. This is a conservative and 2444 bounding approach (see section 6-17).
2445 2446 2447 Table 6-51 Dose Assigned to Clean Concrete Fill Auxiliary Containment SFP/ Turbine Crib House/ WWTF Transfer Forebay Canal Dose 9.94E-01 1.77E+00 1.52E-01 1.58E+00 1.57E+00 6.40E+00 (mrem/yr) 2448 6.15.
2449 6.16.6.17. Demonstrating Compliance with Dose Criterion 2450 There will be four five distinct source terms in the ZNPS End State; backfilled basements, soil, 2451 embedded piping and penetrations, buried piping, and groundwater. Demonstrating compliance 2452 with the Dose Criterion requires the summation of dose from the four five source terms as shown 2453 in Equation 6-11. All penetration inventories will be added to the Basement with the highest 2454 BFM dose regardless of the piping location. The embedded pipeing dose, penetration inventory 2455 dose and clean concrete fill dose (see section 6.16) will be added to the dose inventory from wall 2456 and floor surfaces in the applicable basement to calculate the total basement dose. See LTP 2457 Chapter 5, Table 5-15 for a list of embedded pipe and penetration survey units and which 2458 basement they associated with. where the embedded piping terminates. The only embedded 2459 piping expected in the End State is located in the 560 foot elevation floor of the Turbine 6-79
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2460 Basement. The dose will be summed as shown in Equation 6.5. The maximum total basement 2461 dose will be used for the Max Basement term in Equation 6-11.
2462 The dose summation described in Equation 6-11 is conservative because the various source 2463 terms may not in fact be contiguous or occur at the same time. For example, the maximum open 2464 land soil survey unit dose may be from an area that is not within the footprint of the Basement 2465 with the maximum dose. Another example is the buried pipe that delivers the greatest dose may 2466 not be under or contiguous with the open land survey unit with the maximum dose.
2467 The final compliance dose will be calculated using Equation 6-11 after FSS has been completed 2468 in all survey units. The Release Record for each FSS unit will be reviewed to determine the 2469 maximum mean dose from each for each of the four source terms (e.g. basement, soil, buried 2470 pipe and existing GW if applicable). The compliance dose must be less than 25 mrem/yr. The 2471 calculation of the compliance dose will be documented in the final FSS Report for the site.
2472 The dose summation described in Equation 6.5 is conservative because the various source terms 2473 may not in fact be contiguous or occur at the same time. For example, the maximum open land 2474 soil survey unit dose may be from an area that is not within the footprint of the Basement with 2475 the maximum dose. Another example is the buried pipe that delivers the greatest dose may not 2476 be under or contiguous with the open land survey unit with the maximum dose.
2477 Equation 6-115 2478 2479 = + + +
2480 2481 2482 where:
2483 2484 Compliance Dose = Dose to Resident Farmer Critical Group (mrem/yr) 2485 2486 Max Backfilled Basement = maximum dose from Basements (mrem/yr),
2487 2488 Max Soil = maximum dose from open land survey units (mrem/yr),
2489 2490 Max Buried Piping = maximum dose from buried piping (mrem/yr),
2491 2492 Max Existing Groundwater = maximum dose from existing groundwater (none 2493 expected).
2494 2495 2496 6-80
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2497 6.17.1. Description of Terms in Equation 6-11 2498 This section provides a description of the terms in Equation 6-11 and the method for calculating 2499 the dose for each of the terms.
2500 Max Backfilled Basement 2501 The conceptual model for the basements assumed no water flow and therefore the dose 2502 assessment was performed for each basement separately. Compliance with the dose criterion 2503 must therefore be demonstrated for each basement separately. The dose from different basements 2504 are not additive. TSD 14-009, Revision 2 made several conservative, bounding evaluations of 2505 potential water flow scenarios between basement to confirm the maximum concentrations, and 2506 dose, occurs under the no-flow assumption. These evaluations were predicated on the assumption 2507 that there are no significant elevated areas in the basement that could result in a localized release 2508 exceeding that predicted to occur from surfaces at DCGL concentration.
2509 The process for calculating wall/floor surface DCGLs and implementing the EMC, as described 2510 in this Chapter, and setting embedded pipe and penetration remediation and grouting actions 2511 levels (see LTP Chapter 5, section 5.5.6) ensures that the distribution and levels of residual 2512 radioactivity at license termination will result in uniform release, from all sources at all locations 2513 within the basement at concentrations equal to or below the concentrations predicted in the BFM.
2514 The highest total dose from any individual basement will be used for the Max Backfilled 2515 Basement term in Equation 6-11. The method for calculating the total basement dose is 2516 summarized below.
2517 In a given basement structure, there may be more than one dose component (e.g. surfaces, 2518 penetrations, and embedded pipe) with each dose component comprised of an individual survey 2519 unit. Each dose component survey unit has a unique DCGL. Concrete fill is another dose 2520 component applicable to any basement where clean concrete debris is used as fill. There is a 2521 basement-specific, fixed dose attributed to concrete fill (see section 6-15). The mean Sum of 2522 Fractions (SOF) for concrete fill is calculated by dividing the basement-specific assigned dose in 2523 Table 6-49 by 25 mrem/yr.
2524 After the FSS of all dose components in a given basement is complete and all dose component 2525 survey units pass the Sign Test, the mean SOF for each dose component is calculated. The mean 2526 SOF includes the results of any judgmental samples or elevated areas if the EMC test applied.
2527 The Basement Dose is then calculated by summing the mean SOFs of all dose components using 2528 Equation 6-12.
2529 Equation 6-12:
2530 = ( + + + ) /
2531 Where:
2532 SOFSurface = mean SOF for surface survey unit (walls and floors) 2533 SOFEP = mean SOF for embedded pipe survey unit 2534 SOFPenetration = mean SOF for penetration survey unit 2535 SOFconcrete fill = concrete fill dose from Table 6-45 divided by 25 mrem/yr 6-81
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2536 The calculation of the SOFSurface term may include several basement surface survey units or 2537 judgmental areas as listed in Table 6-23. The method for summing the contributions from 2538 multiple surface survey units in the same basement is described in LTP Chapter 5, section 2539 5.5.7.1.
2540 Max Soil and Max Buried Pipe 2541 Multiple dose components only occur in Basement FSS units. Soil and buried pipe FSS units are 2542 standard, stand-alone survey units.
2543 The calculation of dose for soil and buried pipe terms in Equation 6-10 is straightforward. After 2544 each survey unit passes the Sign Test, the mean SOF (plus judgmental samples and EMC as 2545 applicable) is multiplied by 25 mrem/yr to calculate dose. After FSS of all soil and buried pipe 2546 survey units has been completed, the release records will be reviewed and the maximum SOF for 2547 soil and buried pipe identified. The maximum SOF values will be used as the Max Soil and 2548 Max Buried Pipe terms in Equation 6-11.
2549 Max Existing Groundwater 2550 The maximum existing groundwater dose would be calculated if radionuclides are positively 2551 identified by groundwater monitoring. Groundwater contamination is not expected at Zion. If 2552 groundwater contamination is identified by groundwater monitoring, the maximum SOF will be 2553 calculated from positive results. To calculate dose, a SOF is calculated using the Groundwater 2554 Exposure Factors in Table 6-18 and multiplying by 25 mrem/yr.
6-82
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2555 6.17.6.18. References 2556 6-1 ZionSolutions Technical Support Document 14-003, Conestoga Rovers & Associates 2557 (CRA) Report, Zion Hydrogeologic Investigation Report 2558 6-2 Zion Nuclear Power Station, Units 1 and 2 Asset Sale Agreement - December 2007 2559 6-3 U.S. Nuclear Regulatory Commission NUREG-1575, Supplement 1, Multi-Agency 2560 Radiation Survey and Assessment of Materials and Equipment Manual (MARSAME) -
2561 December 2006 2562 6-3 ZionSolutions TSD 14-016, Description of Embedded Piping, Penetrations and Buried 2563 Piping to Remain in Zion End State 2564 6-4 ZionSolutions Technical Support Document 14-015, Buried Pipe Dose Modeling &
2565 DCGLs 2566 6-5 Zion Station Historical Site Assessment (HSA) - September 2006 2567 6-6 U.S. Nuclear Regulatory Commission NUREG-1757, Volume 2, Revision 1, 2568 Consolidated Decommissioning Guidance - Characterization, Survey, and 2569 Determination of Radiological Criteria, Final Report - September 2003 2570 6-7 ZionSolutions Technical Support Document 14-019, Radionuclides of Concern for Soil 2571 and Basement Fill Model Source Terms 2572 6-8 ZionSolutions Technical Support Document 10-002, Technical Basis for Radiological 2573 Limits for Structure/Building Open Air Demolition 2574 6-9 ZionSolutions Technical Support Document 11-001, Potential Radionuclides of Concern 2575 during the Decommissioning of Zion Station 2576 6-10 Pacific Northwest Laboratory, NUREG/CR-3474, Long-Lived Activation Products in 2577 Reactor Materials, Pacific Northwest Laboratory - 1984 2578 6-11 Pacific Northwest Laboratory, NUREG/CR-4289, Residual Radionuclide Concentration 2579 Within and Around Commercial Nuclear Power Plants; Origin, Distribution, Inventory, 2580 and Decommissioning Assessment - 1985 2581 6-12 Westinghouse Idaho Nuclear Company, Inc., WINCO-1191, Radionuclides in United 2582 States Commercial Nuclear Power Reactors - 1994 2583 6-13 International Commission on Radiological Protection, ICRP Publication 38, 2584 Radiological Transformations - Energy and Intensity of Emissions - 1983 2585 6-14 ZionSolutions Technical Support Document 14-010, RESRAD Dose Modeling for 2586 Basement Fill Model and Soil DCGLs and Calculation of Basement Fill Model Dose 6-83
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2587 Factors and DCGLs 2588 6-15 The City of Zion, Official Zoning Map City of Zion - March 2011 2589 6-16 United States Department of Agriculture, Custom Soil Resources Report Lake County 2590 Illinois - August 2013 2591 6-17 Pacific Northwest Laboratory, NUREG/CR-5512, Volume 1, Residual Radioactive 2592 Contamination from Decommissioning - October 1992 2593 6-18 ZionSolutions TSD 14-009, Brookhaven National Laboratory Report (BNL),
2594 Evaluation of Maximum Radionuclide Groundwater Concentrations for Basement Fill 2595 Model, Zion Station Restoration Project 2596 6-19 ZionSolutions Technical Support Document 14-032, Conestoga Rovers & Associates 2597 Report, Simulation of the Post-Demoltion Saturation of Foundation Fill Using a 2598 Foundation Water Flow Model 2599 6-20 ZionSolutions Technical Support Document 14-006, Conestoga Rovers & Associates 2600 (CRA) Report, Evaluation of Hydrological Parameters in Support of Dose Modeling for 2601 the Zion Restoration Project 2602 6-21 ZionSolutions Technical Support Document 14-004, Brookhaven National Laboratory 2603 (BNL), Recommended Values for the Distribution Coefficient (Kd) to be used in Dose 2604 Assessments for Decommissioning the Zion Nuclear Power Plant 2605 6-22 ZionSolutions Technical Support Document 14-017, Brookhaven National Laboratory 2606 (BNL), Sorption (Kd) Measurements on Cinder Block and Grout in Support of Dose 2607 Assessments for Zion Nuclear Station Decommissioning 2608 6-23 ZionSolutions Technical Support Document 14-020, Brookhaven National Laboratory 2609 (BNL), Sorption (Kd) measurements in Support of Dose Assessments for Zion Nuclear 2610 Station Decommissioning 2611 6-24 Argonne National Laboratory, NUREG/CR-6697 Development of Probabilistic 2612 RESRAD 6.0 and RESRAD-BUILD 3.0 Computer Codes - December 2000 2613 6-25 Sandia National Laboratory, NUREG/CR-5512, Volume 3, Residual Radioactive 2614 Contamination From Decommissioning Parameter Analysis - October 1999 2615 6-26 Environmental Protection Agency, Federal Guidance Report No. 11, Limiting Values of 2616 Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, 2617 Submersion and Ingestion - September 1988 2618 6-27 Environmental Protection Agency, Federal Guidance Report No. 12, External Exposure 2619 to Radionuclides in Air, Water and Soil - September 1993 6-84
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 2620 6-28 ZionSolutions Technical Support Document 14-021 Basement Fill Model (BFM) 2621 Drilling Spoils and Alternate Exposure Scenarios 2622 6-29 U.S. Nuclear Regulatory Commission NUREG-1575, Revision 1, Multi-Agency 2623 Radiation Survey and Site Investigation Manual (MARSSIM) - August 2000 2624 6-30 ZionSolutions Technical Support Document 14-011, Soil Area Factors 2625 6-85
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-1 Zion Nuclear Power Station Geographical Location 6-86
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-2 Zion Nuclear Power Station Owner Controlled Area 6-87
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-3 Zion Nuclear Power Station Security Restricted Area 6-88
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-4 Backfilled Basement and Structures to Remain Below 588 Elevation Page 6-89
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-5 Cross Section A-A of Basements/Structures Below Page 6-90
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-6 Cross Section B-B of Basements/Structures Below 588 Elevation to Remain at License Termination Page 6-91
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-7 Cross Section C-C of Basements/Structures Below 588 Elevation to Remain at License Termination Page 6-92
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-8 Cross Section D-D of Basements/Structures Below 588 Page 6-93
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-9 Visualization of BFM Conceptual Model Page 6-94
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 Figure 6-10 RESRAD Parameter Selection Flow Chart Page 6-95
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 ATTACHMENT 1 RESRAD Input Parameters for ZSRP BFM Uncertainty Analysis Page 6-96
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Soil Concentrations Basic radiation dose limit (mrem/y) 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 (contaminated, unsaturated, and saturated zones) (cm /g) 3 Co-60 P 1 D 223 TSD 14-004 5.46 2.53 0.001 0.999 235 Cs-134 P 1 D 45 TSD 14-004 6.1 2.33 0.001 0.999 446 Cs-137 P 1 D 45 TSD 14-004 6.1 2.33 0.001 0.999 446 Eu-152 P 1 D 95 TSD 14-004 6.72 3.22 0.001 0.999 825 Eu-154 P 1 D 95 TSD 14-004 6.72 3.22 0.001 0.999 825 Gd-152 (daughter for Eu-152) P 1 D 825 Median Value 6.72 3.22 0.001 0.999 825 NUREG/CR-6697, Att. C H-3 P 1 D 0 TSD 14-004 -2.81 0.5 0.001 0.999 0.06 Nd-144 (daughter for Eu-152) P 1 D 158 RESRADv.7.0 Default NA NA NA NA NA Neodymium (Nd) not listed in NUREG/CR-6697 Ni-63 P 1 D 62 TSD 14-004 6.05 1.46 0.001 0.999 424 Sm-148 (daughter Eu-152) P 1 D 825 Median Value 6.72 3.22 0.001 0.999 825 NUREG/CR-6697, Att. C Sr-90 P 1 D 2.3 TSD 14-004 3.45 2.12 0.001 0.999 32 Initial concentration of radionuclides P 3 D 0 No existing groundwater NR NR NR NR present in groundwater (pCi/l) contamination Calculation Times Time since placement of material (y) P 3 D 1 For user convenience: NR NR NR NR Allows use of t=0 in dose and concentration output reports to calculate unitized Exposure Factors Time for calculations (y) P 3 D 0, 1, 3, 10, 30, 100, 300, RESRAD Default NR NR NR NR 1000 Contaminated Zone Area of contaminated zone (m2) P 2 D 64,500 Area of the Security NR NR NR NR Protected Area on Zion Site Page 6-97
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Thickness of contaminated zone (m) P 2 D 11.2 Contaminated Zone is the NR NR NR NR Basement fill depth where mixing occurs. Depth of fill mixing zone depends on Basement floor elevation.
11.2 m is used as nominal value based on difference between elevations of the water table (579) and Auxiliary Basement floor (542) which equals 11.2m.
Note: this parameter has no effect on the calculated values for unitized Exposure Factors.
Length parallel to aquifer flow (m) P 2 D 287 Diameter of 64,500 m2 NR NR NR NR contaminated area.
Note: not applicable to Basement Fill Model because Mass Balance groundwater model used.
Does the initial contamination NA NA NA Yes 100% of the contamination NA NA NA NA penetrate the water table? assumed to be in the basement fill water mixing zone Contaminated fraction below water Pe 3e D 1 100% of the contamination NR NR NR NR table assumed to be in the basement fill water mixing zone Cover and Contaminated Zone Hydrological Data Cover depth (m) P 2 D 3.6m Difference between ground NR NR NR NR NA level elevation at 591 (179.6m) and equilibrium water level in basements at 579 (176m)
Density of cover material P 2 D 1.8 Site-specific average native NR NR NR NR sand and disturbed sand from Reference 6-21, Table 5.5.
Page 6-98
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Cover erosion rate P,B 2 D Continuous Logarithmic NUREG/CR-6697 Att. C 5E-08 0,0007 0,005 .2 0.0015 Density of contaminated zone P 1 S Truncated Normal NUREG/CR-6697 Att. C 1.52 0.23 0.001 0.999 1.52 (g/cm3)
Fill to be comprised of undetermined combination of clean concrete and native sand. NUREG/CR-6697 distribution used as placeholder - parameter has no effect on calculation of unitized Exposure Factors Contaminated zone erosion rate P,B 2 S Continuous Logarithmic NUREG/CR-6697 Att. C 5E-08 0.0007 0,005 0.2 0.0015 (m/y)
Contaminated zone total porosity P 2 S Truncated Normal NUREG/CR-6697 Att. C 0.425 0.0867 0.001 0.999 0.42 Fill to be comprised of undetermined combination of clean concrete and native sand. NUREG/CR-6697 distribution used as placeholder - parameter has no effect on calculation of unitized Exposure Factors Contaminated zone field capacity P 3 D 0.066 Site-specific value from NR NR NR NR Reference 6-21, Table 5.4 Contaminated zone hydraulic P 2 S Loguniform Site-specific distribution 786 17000 NA NA 3649 conductivity (m/y) from Reference 6-21, Table 5.9 Contaminated zone b parameter P 2 S Bounded Lognormal - N NUREG/CR-6697, Att. C 1.06 0.66 0.5 30 2.89 Fill to be comprised of undetermined combination of clean concrete and native sand. NUREG/CR-6697 distribution used as placeholder - parameter has no effect on calculation of unitized Exposure Factors Humidity in air (g/m3) P 3 D 7.2 Median 1.98 0.334 0.001 0.999 7.2 NUREG/CR-6697 Att. C Evapotranspiration coefficient P 2 S Uniform NUREG/CR-6697 Att. C 0.5 0.75 NR NR 0.625 Average annual wind speed (m/s) P 2 S Bounded Lognormal n NUREG/CR-6697 Att. C 1.445 0.2419 1.4 13 4.2 Page 6-99
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Precipitation (m/y) P 2 D 0.83 Site-specific value from NR NR NR NR Reference 6-21, Table 5.12 Irrigation (m/y) B 3 D 0.19 NUREG-5512, Vol. 3, Table NR NR NR NR 6-18 (Illinois Average)
Converted 0.52 L/m2/d to m/y.
Irrigation mode B 3 D Overhead Overhead irrigation is NR NR NR NR common practice in U. S.
Runoff coefficient P 2 S Uniform NUREG/CR-6697 Att. C 0.1 0.8 NR NR 0.45 Watershed area for nearby stream P 3 D 1.0E+06 RESRAD Default NR NR NR NR or pond (m2)
Accuracy for water/soil - 3 D 1.00E-03 RESRAD Default NR NR NR NR computations Saturated Zone Hydrological Data Density of saturated zone (g/cm3) P 1 S Truncated Normal NUREG 6697 distribution 1.51 0.16 0.001 0.999 1.51 for site soil type - sand Saturated zone total porosity P 1 S Truncated Normal NUREG 6697 distribution 0.43 0.06 0.001 0.999 0.43 for site soil type - sand Saturated zone effective porosity P 1 S Truncated Normal NUREG 6697 distribution 0.383 0.0610 0.001 0.999 0.383 for site soil type - sand Saturated zone field capacity P 3 D 0.066 Site-specific value from NR NR NR NR Reference 6-21, Table 5.4 Saturated zone hydraulic P 1 S Loguniform Site-specific distribution 786 17000 NA NA 3649 conductivity (m/y) from Reference 6-21, Table 5.9 Saturated zone hydraulic gradient P 2 S Bounded Lognormal - N NUREG/CR-6697 Att. C -5.11 1.77 0.00007 0.5 0.006 Saturated zone b parameter P 2 D NA NUREG/CR-6697 NR NR NR NR NR saturated zone b not active because water table drop rate =0 Water table drop rate (m/y) P 3 D 0 Basement fill water NR NR NR NR assumed to supply well with no water table drop.
Well pump intake depth (m below P 2 S Triangular NUREG/CR-6697 Att. C 6 10 30 10 water table)
Model: Non-dispersion (ND) or P 3 D MB MB model most applicable NR NR NR NR Mass-Balance (MB) to assumption that well located in center of basement fill.
Page 6-100
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Well pumping rate (m3/y) B,P 2 D 2250 Calculated according to NR NR NR NR NR method described in NUREG/CR-6697, Att. C section 3.10 using Illinois average irrigation rate and NUREG/CR-5512 Vol. 3 livestock water consumption rate. Calculation provided at end of this table as Footnote 1.
Unsaturated Zone Hydrological Data Number of unsaturated zone strata P NA NA 0 No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone thickness (m) P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone soil density (g/cm3) P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone total porosity P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone effective porosity P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone field capacity P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone hydraulic conductivity P NA NA NA No unsaturated zone in NA NA NA NA (m/y) Basement Fill Model Unsat. zone soil-specific b P NA NA NA No unsaturated zone in NA NA NA NA parameter Basement Fill Model Occupancy Inhalation rate (m3/y) M,B 3 D 8400 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.29
(= 23m3/d x 365d)
Mass loading for inhalation (g/m3) P,B 2 S Continuous Linear NUREG/CR-6697, Att. C See See See See 2.35E-05 NUREG- NUREG- NUREG- NUREG-6697 6697 6697 6697 Table Table 4.6-1 Table 4.6- Table 4.6-1 4.6-1 1 Exposure duration B 3 D 30 RESRAD Users Manual NR NR NR NR (Parameter not used in dose calculation)
Indoor dust filtration factor P,B 2 S Uniform NUREG/CR-6697, Att. C 0.15 0.95 0.55 Shielding factor, external gamma P 2 S Bounded Lognormal - N NUREG/CR-6697, Att. C -1.3 0.59 0.044 1 0.27 Page 6-101
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Fraction of time spent indoors B 3 D 0.649 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Fraction of time spent outdoors (on B 3 D 0.124 NUREG/CR-5512, Vol. 3 NR NR NR NR site) Table 6.87 (outdoors +
gardening)
Shape factor flag, external gamma P 3 D Circular Circular contaminated zone NR NR NR NR assumed for modeling purposes Ingestion, Dietary Fruits, non-leafy vegetables, grain M,B 2 D 112 NUREG/CR-5512, Vol. 3 NR NR NR NR consumption (kg/y) Table 6.87 (other vegetables + fruits + grain)
Leafy vegetable consumption (kg/y) M,B 3 D 21.4 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Milk consumption (L/y) M,B 2 D 233 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Meat and poultry consumption (kg/y) M,B 3 D 65.1 NUREG/CR5512, Vol. 3 NR NR NR NR Table 6.87 (beef + poultry)
Fish consumption (kg/y) M,B 3 D 20.6 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Note: Aquatic Pathway inactive in BFM Other seafood consumption (kg/y) M,B 3 D 0.9 RESRAD Users Manual NR NR NR NR Table D.2 Note: Aquatic Pathway inactive in BFM Soil ingestion rate (g/y) M,B 2 D 18.3 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Drinking water intake (L/y) M,B 2 D 478 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Contamination fraction of drinking B,P 3 D 1 All water assumed NR NR NR NR water contaminated Contamination fraction of household B,P 3 NA water (if used)
Contamination fraction of livestock B,P 3 D 1 All water assumed NR NR NR NR water contaminated Contamination fraction of irrigation B,P 3 D 1 All water assumed NR NR NR NR water contaminated Page 6-102
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Contamination fraction of aquatic B,P 2 NA NA Assumption that pond is NR NR NR NR food constructed that intercepts contaminated water not credible at Zion site Contamination fraction of plant food B,P 3 D 1 100% of food consumption NR NR NR NR rate from onsite source Contamination fraction of meat B,P 3 D 1 100% of food consumption NR NR NR NR rate from onsite source Contamination fraction of milk B,P 3 D 1 100% of food consumption NR NR NR NR rate from onsite source Ingestion, Non-Dietary Livestock fodder intake for meat M 3 D 28.3 NUREG/CR5512, Vol. 3 NR NR NR NR (kg/day) Table 6.87 (forage, grain and hay for beef cattle +
poultry + layer hen)
Livestock fodder intake for milk M 3 D 65.2 NUREG/CR5512, Vol. 3 NR NR NR NR (kg/day) Table 6.87 (forage + grain +
hay)
Livestock water intake for meat M 3 D 50.6 NUREG/CR5512, Vol. 3 NR NR NR NR (L/day) Table 6.87 (beef cattle +
poultry + layer hen)
Livestock water intake for milk M 3 D 60 NUREG/CR5512, Vol. 3 NR NR NR NR (L/day) Table 6.87 Livestock soil intake (kg/day) M 3 D 0.5 RESRAD Users Manual, NR NR NR NR Appendix L Mass loading for foliar deposition P 3 D 4.00E-04 NUREG/CR-5512, Vol. 3 NR NR NR NR (g/m3) Table 6.87, gardening Depth of soil mixing layer (m) P 2 S Triangular NUREG/CR-6697, Att. C 0 0.15 0.6 0.23 Depth of roots (m) P 1 S Uniform NUREG/CR-6697, Att. C 0.3 4.0 2.15 Drinking water fraction from ground B,P 3 D 1 All water assumed to be NR NR NR NR water supplied from groundwater Household water fraction from B,P 3 NA Not used ground water (if used)
Livestock water fraction from ground B,P 3 D 1 All water assumed to be NR NR NR NR water supplied from groundwater Irrigation fraction from ground water B,P 3 D 1 All water assumed to be NR NR NR NR supplied from groundwater Wet weight crop yield for Non-Leafy P 2 S Truncated Lognormal - N NUREG/CR-6697, Att. C 0.56 0.48 0.001 0.999 1.75 (kg/m2)
Page 6-103
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Wet weight crop yield for Leafy P 3 D 2.89 NUREG/CR-5512, Vol. 3 NR NR NR NR (kg/m2) Table 6.87 Wet weight crop yield for Fodder P 3 D 1.91 NUREG/CR-5512, Vol. 3 NR NR NR NR (kg/m2) Table 6.87 Growing Season for Non-Leafy (y) P 3 D 0.25 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Growing Season for Leafy (y) P 3 D 0.12 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Growing Season for Fodder (y) P 3 D 0.082 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Translocation Factor for Non-Leafy P 3 D 0.1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Translocation Factor for Leafy P 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Translocation Factor for Fodder P 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Weathering Removal Constant for P 2 S Triangular NUREG/CR-6697, Att. C 5.1 18 84 33 Vegetation (1/y)
Wet Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Non-Leafy Table 6.87 Wet Foliar Interception Fraction for P 2 S Triangular NUREG/CR-6697, Att. C 0.06 0.67 0.95 0.58 Leafy Wet Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Fodder Table 6.87 Dry Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Non-Leafy Table 6.87 Dry Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Leafy Table 6.87 Dry Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Fodder Table 6.87 Storage times of contaminated foodstuffs (days):
Fruits, non-leafy vegetables, and B 3 D 14 NUREG/CR-5512, Vol. 3 NR NR NR NR grain Table 6.87 Leafy vegetables B 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Milk B 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Meat and poultry B 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 (holdup period for beef = 20d and poultry
=1 day. Lowest value used)
Page 6-104
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Fish B 3 D 7 RESRAD Users Manual NR NR NR NR Table D.6 Note: Aquatic pathway inactive in BFM Crustacea and mollusks B 3 D 7 RESRAD Users Manual NR NR NR NR Table D.6 Note: Aquatic pathway inactive in BFM Well water B 3 D 1 RESRAD Users Manual NR NR NR NR Table D.6 Surface water B 3 D 1 RESRAD Users Manual NR NR NR NR Table D.6 Livestock fodder B 3 D 45 RESRAD Users Manual NR NR NR NR Table D.6 Special Radionuclides (C-14)
C-12 concentration in water (g/cm3) P 3 NA NA NA NR NR NR NR C-12 concentration in P 3 NA NA NA NR NR NR NR contaminated soil (g/g)
Fraction of vegetation carbon from P 3 NA NA NA NR NR NR NR soil Fraction of vegetation carbon from P 3 NA NA NA NR NR NR NR air C-14 evasion layer thickness in soil P 2 NA NA NA NR NR NR NR (m)
C-14 evasion flux rate from soil P 3 NA NA NA NR NR NR NR (1/sec)
C-12 evasion flux rate from soil P 3 NA NA NA NR NR NR NR (1/sec)
Fraction of grain in beef cattle feed B 3 NA NA NA NR NR NR NR Fraction of grain in milk cow feed B 3 NA NA NA NR NR NR NR Dose Conversion Factors (Inhalation mrem/pCi)
Co-60 M 3 D 2.19E-04 FGR11 NR NR NR NR Cs-134 M 3 D 4.62E-05 FGR11 NR NR NR NR Cs-137 M 3 D 3.19E-05 FGR11 NR NR NR NR Eu-152 M 3 D 2.21E-04 FGR11 NR NR NR NR Page 6-105
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Eu-154 M 3 D 2.86E-04 FGR11 NR NR NR NR Gd-152 M 3 D 2.43E-01 FGR11 NR NR NR NR H-3 M 3 D 6.40E-08 FGR11 NR NR NR NR Ni-63 M 3 D 6.29E-06 FGR11 NR NR NR NR Nd-144f M 3 D 7.04E-02 ICRP60 NR NR NR NR Sm-148f M 3 D 7.34E-02 ICRP60 NR NR NR NR Sr-90 M 3 D 1.30E-03 FGR11 NR NR NR NR Dose Conversion Factors (Ingestion mrem/pCi)
Co-60 M 3 D 2.69E-05 FGR11 NR NR NR NR Cs-134 M 3 D 7.33E-05 FGR11 NR NR NR NR Cs-137 M 3 D 5.00E-05 FGR11 NR NR NR NR Eu-152 M 3 D 6.48E-06 FGR11 NR NR NR NR Eu-154 M 3 D 9.55E-06 FGR11 NR NR NR NR Gd-152 M 3 D 1.61E-04 FGR11 NR NR NR NR H-3 M 3 D 6.40E-08 FGR11 NR NR NR NR Ni-63 M 3 D 5.77E-07 FGR11 NR NR NR NR Nd-144f M 3 D 1.51E-04 ICRP60 NR NR NR NR Sm-148f M 3 D 1.58E-04 ICRP60 NR NR NR NR Sr-90 M 3 D 1.42E-04 FGR11 NR NR NR NR Plant Transfer Factors (pCi/g plant)/(pCi/g soil)
Co-60 P 1 S Lognormal - N NUREG/CR-6697, Att. C -2.53 0.9 7.9E-02 Cs-134 P 1 S Lognormal - N NUREG/CR-6697, Att. C -3.22 1.0 4.0E-02 Cs-137 P 1 S Lognormal - N NUREG/CR-6697, Att. C -3.22 1.0 4.0E-02 Page 6-106
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Eu-152 P 1 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.1 2.0E-03 Eu-154 P 1 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.1 2.0E-03 Gd-152 P 1 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.1 2.0E-03 H-3 P 1 S Lognormal - N NUREG/CR-6697, Att. C 1.57 1.1 4.8E+00 Nd-144 P 1 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.1 2.0E-03 Ni-63 P 1 S Lognormal - N NUREG/CR-6697, Att. C -3.00 0.9 5.0E-02 Sm-148 P 1 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.1 2.0E-03 Sr-90 P 1 S Lognormal - N NUREG/CR-6697, Att. C -1.20 1.0 3.0E-01 Meat Transfer Factors (pCi/kg)/(pCi/d)
Co-60 P 2 S Lognormal - N NUREG/CR-6697, Att. C -3.51 1.0 3.0E-02 Cs-134 P 2 S Lognormal - N NUREG/CR-6697, Att. C -3.00 0.4 5.0E-02 Cs-137 P 2 S Lognormal - N NUREG/CR-6697, Att. C -3.00 0.4 5.0E-02 Eu-152 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.0 2.0E-03 Eu-154 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.0 2.0E-03 Gd-152 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.0 2.0E-03 H-3 P 2 S Lognormal - N NUREG/CR-6697, Att. C -4.42 1.0 1.2E-02 Nd-144 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.0 2.0E-03 Ni-63 P 2 S Lognormal - N NUREG/CR-6697, Att. C -5.30 0.9 5.0E-03 Sm-148 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 1.1 2.0E-03 Sr-90 P 2 S Lognormal-N NUREG/CR-6697, Att. C -4.61 0.4 1.0E-02 Milk Transfer Factors (pCi/L)/(pCi/d)
Co-60 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 0.7 2.0E-03 Page 6-107
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Cs-134 P 2 S Lognormal - N NUREG/CR-6697, Att. C -4.61 0.5 1.0E-02 Cs-137 P 2 S Lognormal - N NUREG/CR-6697, Att. C -4.61 0.5 1.0E-02 Eu-152 P 2 S Lognormal - N NUREG/CR-6697, Att. C -9.72 0.9 6.0E-05 Eu-154 P 2 S Lognormal - N NUREG/CR-6697, Att. C -9.72 0.9 6.0E-05 Gd-152 P 2 S Lognormal - N NUREG/CR-6697, Att. C -9.72 0.9 6.0E-05 H-3 P 2 S Lognormal - N NUREG/CR-6697, Att. C -4.6 0.9 1.0E-02 Nd-144 P 2 S Lognormal - N NUREG/CR-6697, Att. C -9.72 0.9 6.0E-05 Ni-63 P 2 S Lognormal - N NUREG/CR-6697, Att. C -3.91 0.7 2.0E-02 Sr-90 P 2 S Lognormal - N NUREG/CR-6697, Att. C -6.21 0.5 2.0E-03 Sm-148 P 2 S Lognormal-N NUREG/CR-6697, Att. C -9.72 0.9 6.0E-05 Bioaccumulation Factors for Fish ((pCi/kg)/(pCi/L))
Co-60 P 2 NA Inactive NUREG/CR-6697, Att. C 5.7 1.1 3.0E+02 Cs-134 P 2 NA Inactive NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Cs-137 P 2 NA Inactive NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Eu-152 P 2 NA Inactive NUREG/CR-6697, Att. C 3.9 1.1 4.9E+01 Eu-154 P 2 NA Inactive NUREG/CR-6697, Att. C 3.9 1.1 4.9E+01 Gd-152 P 2 NA Inactive NUREG/CR-6697, Att. C 3.2 1.1 2.5E+01 H-3 P 2 NA Inactive NUREG/CR-6697, Att. C 0 0.1 1.0E+00 Nd-144 P 2 NA Inactive NUREG/CR-6697, Att. C 4.6 1.1 9.9E-01 Ni-63 P 2 NA Inactive NUREG/CR-6697, Att. C 4.6 1.1 9.9E+01 Sm-148 P 2 NA Inactive NUREG/CR-6697, Att. C 3.2 1.1 2.5E+01 Sr-90 P 2 NA Inactive NUREG/CR-6697, Att. C 4.1 1.1 6.0E+01 Bioaccumulation Factors for Crustacea/ Mollusks ((pCi/kg)/(pCi/L))
Co-60 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Cs-134 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Cs-137 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Page 6-108
RESRAD Input Parameters for ZSRP BFM Sensitivity Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Inactive RESRAD Users Manual Eu-152 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Eu-154 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Gd-152 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual H-3 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Nd-144 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Ni-63 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Sm-148 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Sr-90 P 3 NA NR NR NR NR Appendix D 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 Notes: a P = physical, B = behavioral, M = metabolic; (see NUREG/CR-6697, Attachment B, Table 4.)
b 1 = high-priority parameter, 2 = medium-priority parameter, 3 = low-priority parameter (see NUREG/CR-6697, Attachment B, Table 4.1) c D = deterministic, S = stochastic 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 Beta: 1 = minimum, 2 = maximum, 3 = P-value, 4 = Q-value Triangular: 1 = minimum, 2 = mode, 3 = maximum Uniform: 1 = minimum, 2 = maximum Page 6-109
Footnote 1 Basement Fill Model: RESRAD Well Pumping Rate Parameter Calculation Input Value Reference Water Table Elevation 579.00 ft 176.0 m Reference 6-21, Table 5.1 Ground Surface Elevation 591.00 ft 179.7 m Reference 6-21, Table 5.2 Auxiliary Bldg. Floor Surface Area 27484.42 ft2 2540 m2 Reference 6-7, TSD 14-019 Auxiliary Bldg. Floor Elevation 542.00 ft 164.8 m Reference 6-7, TSD 14-019 Demolition Below Grade 3.00 ft 0.9 m Project Plans Post-Dem Wall Height Aux Bldg 46.00 ft 14.0 m Calculation Water Table Height above Aux Floor 37.00 ft 11.2 m Calculation Ground Surface to Water Table 12.00 ft 3.648 m Calculation Cont Zone total porosity 0.35 [1]
Precipitation 0.83 m/y [1]
well pump rate 2250 m3/y NUREG-6697, Table 3.10-1 method inputs 0.52 L/m2/d irrigation rate NUREG-5512, Volume 3, Table 6-18 (Illinios Average) 0.19 m3/m2/yr irrigation rate conversion 10000.00 m2 contaminated area (nominal 2 cattle at ~1 per acre + 2000 m2 garden) [1]
Calculation 328.70 m3 domestic use Reference 6-25, Table 3.10-1 50.6 and 60 L/d (1 dairy 1 meat) 40.37 m3/y livestock Reference 6-25, Table 3.10-1 189.80 m3/y vegetable garden irrigation Reference 6-25, Table 3.10-1 1689.22 m3/y pasture irrigation Reference 6-25, Table 3.10-1 1.64 m3/y drinking water Reference 6-25, Table 3.10-1 Conversion Factors m/ft 0.304 m2/ft2 0.09 Ref [1]: Pastures for Profit: A guide to Rotational Grazing (A3529),
University of Wisconson Extension, 2002.
Page 6-110
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 ATTACHMENT 2 RESRAD Input Parameters for ZSRP BFM Page 6-111
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Soil Concentrations Basic radiation dose limit (mrem/y) NA 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 (contaminated, unsaturated, and saturated zones) (cm3/g)
Co-60 P 1 D 223 TSD 14-004 5.46 2.53 0.001 0.999 235 Cs-134 P 1 D 45 TSD 14-004 6.1 2.33 0.001 0.999 446 Cs-137 P 1 D 45 TSD 14-004 6.1 2.33 0.001 0.999 446 Eu-152 P 1 D 95 TSD 14-004 6.72 3.22 0.001 0.999 825 Eu-154 P 1 D 95 TSD 14-004 6.72 3.22 0.001 0.999 825 Gd-152 (daughter for Eu-152) P 1 D 825 Median Value 6.72 3.22 0.001 0.999 825 NUREG/CR-6697, Att. C H-3 P 1 D 0 TSD 14-004 -2.81 0.5 0.001 0.999 0.06 Nd-144 (daughter for Eu-152) P 1 D 158 RESRADv.7.0 NA NA NA NA NA Default Nd not listed in NUREG/CR-6697 Ni-63 P 1 D 62 TSD 14-004 6.05 1.46 0.001 0.999 424 Sm-148 (daughter Eu-152) P 1 D 825 Median Value 6.72 3.22 0.001 0.999 825 NUREG/CR-6697, Att. C Sr-90 P 1 D 2.3 TSD 14-004 3.45 2.12 0.001 0.999 32 Initial concentration of radionuclides P 3 D 0 No existing groundwater NR NR NR NR present in groundwater (pCi/l) contamination Calculation Times Time since placement of material (y) P 3 D 1 For user convenience: NR NR NR NR Allows use of t=0 in dose and concentration output reports to calculate unitized Exposure Factors Time for calculations (y) P 3 D 0, 1, 3, 10, 30, 100, 300, RESRAD Default NR NR NR NR 1000 Contaminated Zone Area of contaminated zone (m2) P 2 D 64,500 Area of the Radiological NR NR NR NR Protected Area on Zion Site Page 6-112
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Thickness of contaminated zone (m) P 2 D 11.2 Contaminated Zone is the NR NR NR NR Basement fill depth where mixing occurs. Depth of fill mixing zone depends on Basement floor elevation.
11.2 m is used as nominal value based on difference between elevations of the water table (579) and Auxiliary Basement floor (542) which equals 11.2m.
Note: this parameter has no effect on the calculated values for unitized Exposure Factors.
Length parallel to aquifer flow (m) P 2 D 287 Diameter of 64,500 m2 NR NR NR NR contaminated area.
Note: not applicable to Basement Fill Model because Mass Balance groundwater model used.
Does the initial contamination NA NA NA Yes 100% of the contamination NA NA NA NA penetrate the water table? assumed to be in the basement fill water mixing zone Contaminated fraction below water Pe 3e D 1 100% of the contamination NR NR NR NR table assumed to be in the basement fill water mixing zone Cover and Contaminated Zone Hydrological Data Cover depth (m) P 2 D 3.6m Difference between ground NR NR NR NR NA level elevation at 591 (179.6m) and equilibrium water level in basements at 579 (176m)
Density of cover (g/cm3) P 1 D 1.8 Site-specific average native 1.52 0.23 0.001 0.999 1.52 sand and disturbed sand from Reference 6-21, Table 5.5.
Cover erosion rate (m/y) P,B 2 D 0.0015 Median 5E-08 0.0007 0,005 0.2 0.0015 NUREG/CR-6697 Att. C Page 6-113
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Density of contaminated zone P 1 D 1.8 Density identified as 1.52 0.23 0.001 0.999 1.52 (g/cm3) sensitive and positively correlated. The 75th Percentile of the NUREG/CR-6697 Att. C distribution is 1.67 g/cm3.
However, the site-specific value for sand density is 1.8 g/cm3.
Fill to be comprised of undetermined combination of clean concrete and native sand therefore higher value for site-specific sand used.
Contaminated zone erosion rate P,B 2 D 0.0015 Median 5E-08 0.0007 0,005 0.2 0.0015 (m/y) NUREG/CR-6697 Att. C Contaminated zone total porosity P 2 D 0.37 25th Percentile 0.425 0.0867 0.001 0.999 0.42 NUREG/CR-6697 Att. C.
Contaminated zone field capacity P 3 D 0.066 Site-specific value from NR NR NR NR Reference 6-21, Table 5.4 Contaminated zone hydraulic P 2 D 2880 Site-specific value from 786 17000 NA NA 3649 conductivity (m/y) Reference 6-21, Table 5.9 Contaminated zone b parameter P 2 D 2.89 Median 1.06 0.66 0.5 30 2.89 NUREG/CR-6697, Att. C Humidity in air (g/m3) P 3 D 7.2 Median 1.98 0.334 0.001 0.999 7.2 NUREG/CR-6697 Att. C Evapotranspiration coefficient P 2 D 0.625 Median 0.5 0.75 NR NR 0.625 NUREG/CR-6697 Att. C Average annual wind speed (m/s) P 2 D 4.2 Median 1.445 0.2419 1.4 13 4.2 NUREG/CR-6697 Att. C Precipitation (m/y) P 2 D 0.83 Site-specific value from NR NR NR NR Reference 6-21, Table 5.12 Irrigation (m/y) B 3 D 0.19 NUREG-5512, Vol. 3, Table NR NR NR NR 6-18 (Illinois Average).
Converted 0.52 L/m2/d to m/y.
Irrigation mode B 3 D Overhead Overhead irrigation is NR NR NR NR common practice in U. S.
Runoff coefficient P 2 D 0.2 Site-specific value from 0.1 0.8 NR NR 0.45 Reference 6-21, Section 5.10 Watershed area for nearby stream P 3 D 1.0E+06 RESRAD Default NR NR NR NR or pond (m2)
Page 6-114
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Accuracy for water/soil - 3 D 1.00E-03 RESRAD Default NR NR NR NR computations Saturated Zone Hydrological Data Density of saturated zone (g/cm3) P 1 D 1.8 Site-specific average native 1.51 0.16 0.001 0.999 1.51 sand and disturbed sand from Reference 6-21, Table 5.5.
Saturated zone total porosity P 1 D 0.35 Site-specific average native 0.43 0.06 0.001 0.999 0.43 sand and disturbed sand from Reference 6-21, Table 5.6 Saturated zone effective porosity P 1 D 0.29 Site-specific average native 0.383 0.0610 0.001 0.999 0.383 sand and disturbed sand from Reference 6-21, Table 5.7 Saturated zone field capacity P 3 D 0.066 Site-specific value from NR NR NR NR Reference 6-21, Table 5.4 Saturated zone hydraulic P 1 D 1695 25th percentile 786 17000 NA NA 3649 conductivity (m/y) Site-specific distribution from Reference 6-21, Table 5.9.
Saturated zone hydraulic gradient P 2 D 0.0018 25th Percentile -0.511 1.77 0.00007 0.5 0.006 NUREG/CR-6697 Att. C distribution Site-specific average native sand and disturbed sand from Reference 6-21, Table 5.10 is greater at 0.0039 but lower value used Saturated zone b parameter P 2 D NA RESRAD User Manual NR NR NR NR NR saturated zone b not active in RESRAD because water table drop rate =0 Water table drop rate (m/y) P 3 D 0 Basement fill water NR NR NR NR assumed to fully supply well.
Page 6-115
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Well pump intake depth (m below P 2 D 5.6 Basement depths vary. 6 10 30 NA 10 water table) 5.2m selected as nominal value based on mid-point of 11.2m contaminated zone for Auxiliary Basement.
Note: this parameter has no effect on the calculated values for unitized Exposure Factors.
Model: Non-dispersion (ND) or P 3 D MB MB model most applicable NR NR NR NR Mass-Balance (MB) to assumption that well located in center of basement fill.
Well pumping rate (m3/y) B,P 2 D 2250 Calculated according to NR NR NR NR NR method described in NUREG/CR-6697, Att. C Section 3.10 using Illinois specific irrigation rate and NUREG/CR-5512 vol. 3 livestock water consumption rate.
Unsaturated Zone Hydrological Data Number of unsaturated zone strata P NA NA 0 No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone thickness (m) P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone soil density (g/cm3) P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone total porosity P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone effective porosity P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone field capacity P NA NA NA No unsaturated zone in NA NA NA NA Basement Fill Model Unsat. zone hydraulic conductivity P NA NA NA No unsaturated zone in NA NA NA NA (m/y) Basement Fill Model Unsat. zone soil-specific b P NA NA NA No unsaturated zone in NA NA NA NA parameter Basement Fill Model Occupancy Page 6-116
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Inhalation rate (m3/y) M,B 3 D 8400 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.29
(= 23 m3/d x 365 d/y)
Mass loading for inhalation (g/m3) P,B 2 D 2.35E-05 Median See See See See 2.35E-05 NUREG/CR-6697, Att. C NUREG- NUREG- NUREG- NUREG-6697 6697 6697 Table 6697 Table Table 4.6-1 4.6-1 Table 4.6-1 4.6-1 Exposure duration B 3 D 30 RESRAD Users Manual NR NR NR NR (Parameter not used in dose calculation)
Indoor dust filtration factor P,B 2 D 0.55 Median 0.15 0.95 0.55 NUREG/CR-6697, Att. C Shielding factor, external gamma P 2 D 0.27 Median -1.3 0.59 0.044 1 0.27 NUREG/CR-6697, Att. C Fraction of time spent indoors B 3 D 0.649 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Fraction of time spent outdoors (on B 3 D 0.124 NUREG/CR-5512, Vol. 3 NR NR NR NR site) Table 6.87 (outdoors +
gardening)
Shape factor flag, external gamma P 3 D Circular Circular contaminated zone NR NR NR NR assumed for modeling purposes Ingestion, Dietary Fruits, non-leafy vegetables, grain M,B 2 D 112 NUREG/CR-5512, Vol. 3 NR NR NR NR consumption (kg/y) Table 6.87 (other vegetables + fruits + grain)
Leafy vegetable consumption (kg/y) M,B 3 D 21.4 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Milk consumption (L/y) M,B 2 D 233 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Meat and poultry consumption (kg/y) M,B 3 D 65.1 NUREG/CR5512, Vol. 3 NR NR NR NR Table 6.87 (beef + poultry)
Fish consumption (kg/y) M,B 3 D 20.6 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Note: Aquatic Pathway inactive in BFM Page 6-117
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Other seafood consumption (kg/y) M,B 3 D 0.9 RESRAD Users Manual NR NR NR NR Table D.2 Note: Aquatic Pathway inactive in BFM Soil ingestion rate (g/y) M,B 2 D 18.3 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Drinking water intake (L/y) M,B 2 D 478 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Contamination fraction of drinking B,P 3 D 1 All water assumed NR NR NR NR water contaminated Contamination fraction of household B,P 3 NA water (if used)
Contamination fraction of livestock B,P 3 D 1 All water assumed NR NR NR NR water contaminated Contamination fraction of irrigation B,P 3 D 1 All water assumed NR NR NR NR water contaminated Contamination fraction of aquatic B,P 2 D NA Assumption that pond is NR NR NR NR food constructed that intercepts contaminated water not credible at Zion site Contamination fraction of plant food B,P 3 D 1 100% of food consumption NR NR NR NR rate from onsite source Contamination fraction of meat B,P 3 D 1 100% of food consumption NR NR NR NR rate from onsite source Contamination fraction of milk B,P 3 D 1 100% of food consumption NR NR NR NR rate from onsite source Ingestion, Non-Dietary Livestock fodder intake for meat M 3 D 28.3 NUREG/CR5512, Vol. 3 NR NR NR NR (kg/day) Table 6.87 (forage, grain and hay for beef cattle +
poultry + layer hen)
Livestock fodder intake for milk M 3 D 65.2 NUREG/CR5512, Vol. 3 NR NR NR NR (kg/day) Table 6.87 (forage + grain +
hay)
Livestock water intake for meat M 3 D 50.6 NUREG/CR5512, Vol. 3 NR NR NR NR (L/day) Table 6.87 (beef cattle +
poultry + layer hen)
Livestock water intake for milk M 3 D 60 NUREG/CR5512, Vol. 3 NR NR NR NR (L/day) Table 6.87 Livestock soil intake (kg/day) M 3 D 0.5 RESRAD Users Manual, NR NR NR NR Appendix L Mass loading for foliar deposition P 3 D 4.00E-04 NUREG/CR-5512, Vol. 3 NR NR NR NR (g/m3) Table 6.87, gardening Page 6-118
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Depth of soil mixing layer (m) P 2 D 0.23 Median 0 0.15 0.6 0.23 NUREG/CR-6697, Att. C Depth of roots (m) P 1 D 3.1 75th Percentile 0.3 4.0 2.15 NUREG/CR-6697, Att. C Drinking water fraction from ground B,P 3 D 1 All water assumed to be NR NR NR NR water supplied from groundwater Household water fraction from B,P 3 NA ground water (if used)
Livestock water fraction from ground B,P 3 D 1 All water assumed to be NR NR NR NR water supplied from groundwater Irrigation fraction from ground water B,P 3 D 1 All water assumed to be NR NR NR NR supplied from groundwater Wet weight crop yield for Non-Leafy P 2 D 1.26 25th Percentile 0.56 0.48 0.001 0.999 1.75 (kg/m2) NUREG/CR-6697, Att. C Wet weight crop yield for Leafy P 3 D 2.89 NUREG/CR-5512, Vol. 3 NR NR NR NR (kg/m2) Table 6.87 Wet weight crop yield for Fodder P 3 D 1.91 NUREG/CR-5512, Vol. 3 NR NR NR NR (kg/m2) Table 6.87 (maximum of forage, grain and hay)
Growing Season for Non-Leafy (y) P 3 D 0.25 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Growing Season for Leafy (y) P 3 D 0.12 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Growing Season for Fodder (y) P 3 D 0.082 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Translocation Factor for Non-Leafy P 3 D 0.1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Translocation Factor for Leafy P 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Translocation Factor for Fodder P 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Weathering Removal Constant for P 2 D 21.5 25th Percentile 5.1 18 84 33 Vegetation (1/y) NUREG/CR-6697, Att. C Wet Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Non-Leafy Table 6.87 Wet Foliar Interception Fraction for P 2 D 0.70 75th Percentile 0.06 0.67 0.95 0.58 Leafy NUREG/CR-6697, Att. C Wet Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Fodder Table 6.87 Dry Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Non-Leafy Table 6.87 Page 6-119
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Dry Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Leafy Table 6.87 Dry Foliar Interception Fraction for P 3 D 0.35 NUREG/CR-5512, Vol. 3 NR NR NR NR Fodder Table 6.87 Storage times of contaminated foodstuffs (days):
Fruits, non-leafy vegetables, and B 3 D 14 NUREG/CR-5512, Vol. 3 NR NR NR NR grain Table 6.87 Leafy vegetables B 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Milk B 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 Meat and poultry B 3 D 1 NUREG/CR-5512, Vol. 3 NR NR NR NR Table 6.87 (holdup period for beef = 20d and poultry
=1 day. Lowest value used)
Fish B 3 D 7 RESRAD Users Manual NR NR NR NR Table D.6 Note: Aquatic pathway inactive in BFM Crustacea and mollusks B 3 D 7 RESRAD Users Manual NR NR NR NR Table D.6 Note: Aquatic pathway inactive in BFM Well water B 3 D 1 RESRAD Users Manual NR NR NR NR Table D.6 Surface water B 3 D 1 RESRAD Users Manual NR NR NR NR Table D.6 Livestock fodder B 3 D 45 RESRAD Users Manual NR NR NR NR Table D.6 Special Radionuclides (C-14)
C-12 concentration in water (g/cm3) P 3 D NA NA NR NR NR NR C-12 concentration in P 3 D NA NA NR NR NR NR contaminated soil (g/g)
Fraction of vegetation carbon from P 3 D NA NA NR NR NR NR soil Fraction of vegetation carbon from P 3 D NA NA NR NR NR NR air C-14 evasion layer thickness in soil P 2 D NA NA NR NR NR NR (m)
C-14 evasion flux rate from soil P 3 D NA NA NR NR NR NR (1/sec)
Page 6-120
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median C-12 evasion flux rate from soil P 3 D NA NA NR NR NR NR (1/sec)
Fraction of grain in beef cattle feed B 3 D NA NA NR NR NR NR Fraction of grain in milk cow feed B 3 D NA NA NR NR NR NR Dose Conversion Factors (Inhalation mrem/pCi)
Co-60 M 3 D 2.19E-04 FGR11 NR NR NR NR Cs-134 M 3 D 4.62E-05 FGR11 NR NR NR NR Cs-137 M 3 D 3.19E-05 FGR11 NR NR NR NR Eu-152 M 3 D 2.21E-04 FGR11 NR NR NR NR Eu-154 M 3 D 2.86E-04 FGR11 NR NR NR NR Gd-152 M 3 D 2.43E-01 FGR11 NR NR NR NR H-3 M 3 D 6.40E-08 FGR11 NR NR NR NR Nd-144f M 3 D 7.04E-02 ICRP60 NR NR NR NR Ni-63 M 3 D 6.29E-06 FGR11 NR NR NR NR Sm-148f M 3 D 7.34E-02 ICRP60 NR NR NR NR Sr-90 M 3 D 1.30E-03 FGR11 NR NR NR NR Dose Conversion Factors (Ingestion mrem/pCi)
Co-60 M 3 D 2.69E-05 FGR11 NR NR NR NR Cs-134 M 3 D 7.33E-05 FGR11 NR NR NR NR Cs-137 M 3 D 5.00E-05 FGR11 NR NR NR NR Eu-152 M 3 D 6.48E-06 FGR11 NR NR NR NR Eu-154 M 3 D 9.55E-06 FGR11 NR NR NR NR Gd-152 M 3 D 1.61E-04 FGR11 NR NR NR NR H-3 M 3 D 6.40E-08 FGR11 NR NR NR NR Page 6-121
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Nd-144f M 3 D 1.51E-04 ICRP60 NR NR NR NR Ni-63 M 3 D 5.77E-07 FGR11 NR NR NR NR Sm-148f M 3 D 1.58E-04 ICRP60 NR NR NR NR Sr-90 M 3 D 1.42E-04 FGR11 NR NR NR NR Plant Transfer Factors (pCi/g plant)/(pCi/g soil)
Co-60 P 1 D 7.9E-02 Median -2.53 0.9 7.9E-02 NUREG/CR-6697, Att. C Cs-134 P 1 D 4.0E-02 Median -3.22 1.0 4.0E-02 NUREG/CR-6697, Att. C Cs-137 P 1 D 4.0E-02 Median -3.22 1.0 4.0E-02 NUREG/CR-6697, Att. C Eu-152 P 1 D 2.0E-03 Median -6.21 1.1 2.0E-03 NUREG/CR-6697, Att. C Eu-154 P 1 D 2.0E-03 Median -6.21 1.1 2.0E-03 NUREG/CR-6697, Att. C Gd-152 P 1 D 2.0E-03 Median -6.21 1.1 2.0E-03 NUREG/CR-6697, Att. C H-3 P 1 D 4.8E+00 Median 1.57 1.1 4.8E+00 NUREG/CR-6697, Att. C Nd-144 P 1 D 2.0E-03 Median -6.21 1.1 2.0E-03 NUREG/CR-6697, Att. C Ni-63 P 1 D 5.0E-02 Median -3.00 0.9 5.0E-02 NUREG/CR-6697, Att. C Sm-148 P 1 D 2.0E-03 Median -6.21 1.1 2.0E-03 NUREG/CR-6697, Att. C Sr-90 P 1 D 5.9E-01 75th Percentile -1.20 1.0 3.0E-01 NUREG/CR-6697, Att. C Meat Transfer Factors (pCi/kg)/(pCi/d)
Co-60 P 2 D 0.058 75th Percentile -3.51 1.0 3.0E-02 NUREG/CR-6697, Att. C Cs-134 P 2 D 0.065 75th Percentile -3.00 0.4 5.0E-02 NUREG/CR-6697, Att. C Cs-137 P 2 D 0.065 75th Percentile -3.00 0.4 5.0E-02 NUREG/CR-6697, Att. C Eu-152 P 2 D 0.004 75th Percentile -6.21 1.0 2.0E-03 NUREG/CR-6697, Att. C Eu-154 P 2 D 0.004 75th Percentile -6.21 1.0 2.0E-03 NUREG/CR-6697, Att. C Page 6-122
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Gd-152 P 2 D 2.0E-03 Median -6.21 1.0 2.0E-03 NUREG/CR-6697, Att. C H-3 P 2 D 0.012 Median -4.42 1.0 0.012 NUREG/CR-6697, Att. C Nd-144 P 2 D 2.0E-03 Median -6.21 1.0 2.0E-03 NUREG/CR-6697, Att. C Ni-63 P 2 D 0.0092 75th Percentile -5.30 0.9 5.0E-03 NUREG/CR-6697, Att. C Sm-148 P 2 D 2.0E-03 Median -6.21 1.1 2.0E-03 NUREG/CR-6697, Att. C Sr-90 P 2 D 0.013 75th Percentile -4.61 0.4 1.0E-02 NUREG/CR-6697, Att. C Milk Transfer Factors (pCi/L)/(pCi/d)
Co-60 P 2 D 0.0032 75th Percentile -6.21 0.7 2.0E-03 NUREG/CR-6697, Att. C Cs-134 P 2 D 1.4E-02 75th Percentile -4.61 0.5 1.0E-02 NUREG/CR-6697, Att. C Cs-137 P 2 D 1.4E-02 75th Percentile -4.61 0.5 1.0E-02 NUREG/CR-6697, Att. C Eu-152 P 2 D 6.0E-05 Median -9.72 0.9 6.0E-05 NUREG/CR-6697, Att. C Eu-154 P 2 D 6.0E-05 Median -9.72 0.9 6.0E-05 NUREG/CR-6697, Att. C Gd-152 P 2 D 6.0E-05 Median -9.72 0.9 6.0E-05 NUREG/CR-6697, Att. C H-3 P 2 D 0.010 Median -4.6 0.9 1.0E-02 NUREG/CR-6697, Att. C Nd-144 P 2 D 6.0E-05 Median -9.72 0.9 6.0E-05 NUREG/CR-6697, Att. C Ni-63 P 2 D 0.032 75th Percentile -3.91 0.7 2.0E-02 NUREG/CR-6697, Att. C Sm-148 P 2 D 6.0E-05 Median -9.72 0.9 6.0E-05 NUREG/CR-6697, Att. C Sr-90 P 2 D 0.0028 75th Percentile -6.21 0.5 2.0E-03 NUREG/CR-6697, Att. C Bioaccumulation Factors for Fish ((pCi/kg)/(pCi/L))
Co-60 P 2 NA Inactive NUREG/CR-6697, Att. C 5.7 1.1 3.0E+02 Cs-134 P 2 NA Inactive NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Cs-137 P 2 NA Inactive NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Page 6-123
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Eu-152 P 2 NA Inactive NUREG/CR-6697, Att. C 3.9 1.1 4.9E+01 Eu-154 P 2 NA Inactive NUREG/CR-6697, Att. C 3.9 1.1 4.9E+01 Gd-152 P 2 NA Inactive NUREG/CR-6697, Att. C 3.2 1.1 2.5E+01 H-3 P 2 NA Inactive NUREG/CR-6697, Att. C 0 0.1 1.0E+00 Nd-144 P 2 NA Inactive NUREG/CR-6697, Att. C 4.6 1.1 9.9E-01 Ni-63 P 2 NA Inactive NUREG/CR-6697, Att. C 4.6 1.1 1.0E+02 Sm-148 P 2 NA Inactive NUREG/CR-6697, Att. C 3.2 1.1 2.5E+01 Sr-90 P 2 NA Inactive NUREG/CR-6697, Att. C 4.1 1.1 6.0E+01 Bioaccumulation Factors for Crustacea/ Mollusks ((pCi/kg)/(pCi/L))
Co-60 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Cs-134 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Cs-137 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Eu-152 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Eu-154 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Gd-152 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D H-3 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Nd-144 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Ni-63 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Sm-148 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Sr-90 P 3 NA Inactive RESRAD Users Manual NR NR NR NR Appendix D Graphics Parameters Number of points 32 RESRAD Default NR NR NR NR Page 6-124
Parameter (unit)
Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Spacing log RESRAD Default NR NR NR NR Time integration parameters Maximum number of points for dose 17 RESRAD Default NR NR NR NR Notes:
a P = physical, B = behavioral, M = metabolic; (see NUREG/CR-6697, Attachment B, Table 4.)
b 1 = high-priority parameter, 2 = medium-priority parameter, 3 = low-priority parameter (see NUREG/CR-6697, Attachment B, Table 4.1) c D = deterministic, S = stochastic 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 Beta: 1 = minimum, 2 = maximum, 3 = P-value, 4 = Q-value Triangular: 1 = minimum, 2 = mode, 3 = maximum Uniform: 1 = minimum, 2 = maximum Page 6-125
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 ATTACHMENT 3 RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil Uncertainty Analysis Page 6-126
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Soil Concentrations Basic radiation dose limit (mrem/y) 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 (contaminated, unsaturated, and saturated zones) (cm3/g)
Co-60 P 1 D 1161 TSD 14-004 5.46 2.53 0.001 0.999 235 Cs-134 P 1 D 615 TSD 14-0042 6.1 2.33 0.001 0.999 446 Cs-137 P 1 D 615 TSD 14-004 6.1 2.33 0.001 0.999 446 Ni-63 P 1 D 62 TSD 14-004 6.05 1.46 0.001 0.999 424 Sr-90 P 1 D 2.3 TSD 14-004 3.45 2.12 0.001 0.999 32 Initial concentration of radionuclides No existing groundwater P 3 D 0 NR NR NR NR present in groundwater (pCi/l) contamination Calculation Times Time since placement of material (y) P 3 D 0 RESRAD Default NR NR NR NR 0, 1, 3, 10, 30, 100, 300, Time for calculations (y) P 3 D RESRAD Default NR NR NR NR 1000 Contaminated Zone Area of the Security Area of contaminated zone (m2) P 2 D 64,500 NR NR NR NR Protected Area on Zion Site D
Surface soil depth 0.15 Thickness of contaminated zone (m) P 2 0.15 or 1 NR NR NR NR Subsurface soil depth 1 m 287 Diameter of 64,500 m2 Length parallel to aquifer flow (m) P 2 D NR NR NR NR contaminated area.
Does the initial contamination No contamination in water NA NA NA No NA NA NA NA penetrate the water table? table Contaminated fraction below water No contamination in water Pe 3e D 0 NR NR NR NR table table Cover and Contaminated Zone Hydrological Data Cover depth (m) P 2 D 0 No Cover NR NR NR NR NA Density of cover (g/cm ) 3 P 1 NA NA No Cover NA NA NA NA NA NUREG/CR-6697 Att. C Cover erosion rate (m/y) P,B 2 NA Continuous Logarithmic 5E-08 0.0007 0.005 0.2 0.0015 Table 3.8-1 Page 6-127
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Density of contaminated zone NUREG 6697 distribution P 1 S Truncated Normal 1.51 0.16 0.001 0.999 1.51 (g/cm3) for site soil type - sand Contaminated zone erosion rate NUREG/CR-6697 Att. C P,B 2 S Continuous Logarithmic 5E-08 0.0007 0.005 0.2 0.0015 (m/y) Table 3.8-1 NUREG 6697 distribution Contaminated zone total porosity P 2 S Truncated Normal 0.43 0.06 0.001 0.999 0.43 for site soil type - sand D 0.066 Site-specific value from Contaminated zone field capacity P 3 NR NR NR NR Reference 6-21, Table 5.4 Site-specific distribution Contaminated zone hydraulic Loguniform P 2 S from Reference 6-21, Table 786 17000 NA NA 3649 conductivity (m/y) 5.9 NUREG 6697 distribution 0.97 Contaminated zone b parameter P 2 S Truncated Lognormal - N -.0253 0.216 0.001 0.999 for site soil type - sand Median Humidity in air (g/m3) P 3 D 7.2 1.98 0.334 0.001 0.999 7.2 NUREG/CR-6697 Att. C S
Evapotranspiration coefficient P 2 Uniform NUREG/CR-6697 Att. C 0.5 0.75 NR NR 0.625 S
Average annual wind speed (m/s) P 2 Bounded Lognormal N NUREG/CR-6697 Att. C 1.445 0.2419 1.4 13 4.2 D Site-specific value from Precipitation (m/y) P 2 0.83 NR NR NR NR Reference 6-21, Table 5.12 NUREG-5512, Vol. 3, Table 6-18 (Illinois Average)
D Irrigation (m/y) B 3 0.19 NR NR NR NR 0.56 Converted 0.52 L/m2/y to m/y Overhead irrigation is Irrigation mode B 3 D Overhead NR NR NR NR common practice in U. S.
Runoff coefficient P 2 S Uniform NUREG/CR-6697 Att. C 0.1 0.8 NR NR 0.45 Watershed area for nearby stream P 3 D 1.0E+06 RESRAD Default NR NR NR NR or pond (m2)
Accuracy for water/soil
- 3 D 1.00E-03 RESRAD Default NR NR NR NR computations Saturated Zone Hydrological Data NUREG 6697 distribution Density of saturated zone (g/cm3) P 1 S Truncated Normal 1.51 0.16 0.001 0.999 1.51 for site soil type - sand NUREG 6697 distribution Saturated zone total porosity P 1 S Truncated Normal 0.43 0.06 0.001 0.999 0.43 for site soil type - sand NUREG 6697 distribution 0.383 Saturated zone effective porosity P 1 S Truncated Normal 0.383 0.0610 0.001 0.999 for site soil type - sand 0.066 Site-specific value from Saturated zone field capacity P 3 D NR NR NR NR Reference 6-21, Table 5.4 Page 6-128
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Site-specific distribution Saturated zone hydraulic Loguniform P 1 S from Reference 6-21, Table 786 17000 NA NA 3649 conductivity (m/y) 5.9 Saturated zone hydraulic gradient P 2 S Bounded Lognormal - N NUREG/CR-6697 Att. C -5.11 1.77 0.00007 0.5 0.006 NA saturated zone b not active NR Saturated zone b parameter P 2 D NUREG/CR-6697 Att. C NR NR NR NR because water table drop rate =0 Well pumping rate assumed Water table drop rate (m/y) P 3 D 0 small relative to water table NR NR NR NR volume.
Well pump intake depth (m below P 2 S Triangular NUREG/CR-6697 6 10 30 10 water table)
Model: Non-dispersion (ND) or P 3 D ND Non Dispersion Model used NR NR NR NR Mass-Balance (MB)
Calculated according to method described in NUREG/CR-6697, Att. C Well pumping rate (m3/y) B,P 2 S 2250 Section 3.10 using Illinois NR NR NR NR NR specific irrigation rate and NUREG/CR-5512 vol. 3 livestock water intake rate Unsaturated Zone Hydrological Data Number of unsaturated zone strata P 3 D 1 One unsaturated zone NA NA NA NA Distance from ground surface (591) to water table (579) = 3.6 3.45 Reference 6-21, Tables 5.1 (for 0.15 m contaminated and 5.2 zone thickness)
For 0.15 m contaminated Unsat. zone thickness (m) P 1 D 2.6 NA NA NA NA zone thickness unsaturated (for 1.0 m contaminated zone = 3.6 - 0.15 = 3.45 m zone thickness)
For 1.0 m contaminated zone thickness unsaturated zone = 3.6 - 1.0 = 2.6 m NUREG 6697 distribution Unsat. zone soil density (g/cm3) P 2 S Truncated Normal 1.51 0.16 0.001 0.999 1.51 for site soil type - sand NUREG 6697 distribution Unsat. zone total porosity P 2 S Truncated Normal 0.43 0.06 0.001 0.999 0.43 for site soil type - sand Page 6-129
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median NUREG 6697 distribution 0.383 Unsat. zone effective porosity P 2 S Truncated Normal 0.383 0.0610 0.001 0.999 for site soil type - sand 0.066 Site-specific value from Unsat. zone field capacity P 3 D NR NR NR NR Reference 6-21, Table 5.4 Site-specific distribution Unsat. zone hydraulic conductivity Loguniform P 2 S from Reference 6-21, Table 786 17000 NA NA 3649 (m/y) 5.9 Unsat. zone soil-specific b NUREG 6697 distribution 0.97 P 2 S Truncated Lognormal - N -.0253 0.216 0.001 0.999 parameter for site soil type - sand Occupancy NUREG/CR-5512, Vol. 3 Inhalation rate (m3/y) M,B 3 D 8400 Table 6.29 NR NR NR NR (23 m3/d x 365 d)
See See See See NUREG- NUREG-NUREG- NUREG-Mass loading for inhalation (g/m )
3 P,B 2 S Continuous Linear NUREG/CR-6697, Att. C 6697 6697 2.35E-05 6697 6697 Table Table 4.6-Table 4.6-1 Table 4.6-1 4.6-1 1 RESRAD Users Manual Exposure duration B 3 D 30 (Parameter not used in dose NR NR NR NR calculation)
Indoor dust filtration factor P,B 2 S Uniform NUREG/CR-6697, Att. C 0.15 0.95 0.55 Shielding factor, external gamma P 2 S Bounded Lognormal - N NUREG/CR-6697, Att. C -1.3 0.59 0.044 1 0.2725 NUREG/CR-5512, Vol. 3 Fraction of time spent indoors B 3 D 0.649 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Fraction of time spent outdoors (on B 3 D 0.124 Table 6.87 (outdoors + NR NR NR NR site) gardening)
Circular contaminated zone assumed for modeling purposes Shape factor flag, external gamma P 3 D Circular NR NR NR NR Ingestion, Dietary NUREG/CR-5512, Vol. 3 Fruits, non-leafy vegetables, grain M,B 2 D 112 Table 6.87 (other NR NR NR NR consumption (kg/y) vegetables + fruits + grain)
NUREG/CR-5512, Vol. 3 Leafy vegetable consumption (kg/y) M,B 3 D 21.4 NR NR NR NR Table 6.87 Page 6-130
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median NUREG/CR-5512, Vol. 3 Milk consumption (L/y) M,B 2 D 233 NR NR NR NR Table 6.87 M,B NUREG/CR5512, Vol. 3 Meat and poultry consumption (kg/y) 3 D 65.1 NR NR NR NR Table 6.87 (beef + poultry)
NUREG/CR-5512, Vol. 3 Table 6.87 M,B Fish consumption (kg/y) 3 D 20.6 NR NR NR NR Note: Aquatic Pathway inactive RESRAD Users Manual Table D.2 M,B Other seafood consumption (kg/y) 3 D 0.9 NR NR NR NR Note: Aquatic Pathway inactive M,B NUREG/CR-5512, Vol. 3 Soil ingestion rate (g/y) 2 D 18.3 NR NR NR NR Table 6.87 M,B NUREG/CR-5512, Vol. 3 Drinking water intake (L/y) 2 D 478 NR NR NR NR Table 6.87 Contamination fraction of drinking All water assumed B,P 3 D 1 NR NR NR NR water contaminated Contamination fraction of household B,P 3 NA water (if used)
Contamination fraction of livestock All water assumed B,P 3 D 1 NR NR NR NR water contaminated Contamination fraction of irrigation All water assumed B,P 3 D 1 NR NR NR NR water contaminated Assumption that pond is Contamination fraction of aquatic constructed that intercepts B,P 2 D NA NR NR NR NR food contaminated water not credible at Zion site 100% of food consumption Contamination fraction of plant food B,P 3 D 1 NR NR NR NR assumed contaminated 100% of food consumption Contamination fraction of meat B,P 3 D 1 NR NR NR NR assumed contaminated 1
Contamination fraction of milk 100% of food consumption B,P 3 D NR NR NR NR assumed contaminated Ingestion, Non-Dietary Page 6-131
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median NUREG/CR5512, Vol. 3 Livestock fodder intake for meat Table 6.87 (forage, grain M 3 D 28.3 NR NR NR NR (kg/day) and hay for beef cattle +
poultry + layer hen)
NUREG/CR5512, Vol. 3 Livestock fodder intake for milk M 3 D 65.2 Table 6.87 (forage + grain + NR NR NR NR (kg/day) hay)
NUREG/CR5512, Vol. 3 Livestock water intake for meat M 3 D 50.6 Table 6.87 (beef cattle + NR NR NR NR (L/day) poultry + layer hen)
Livestock water intake for milk NUREG/CR5512, Vol. 3 M 3 D 60 NR NR NR NR (L/day) Table 6.87 RESRAD Users Manual, Livestock soil intake (kg/day) M 3 D 0.5 NR NR NR NR Appendix L Mass loading for foliar deposition NUREG/CR-5512, Vol. 3 P 3 D 4.00E-04 NR NR NR NR (g/m3) Table 6.87, gardening Depth of soil mixing layer (m) P 2 S Triangular NUREG/CR-6697, Att. C 0 0.15 0.6 0.23 4.0 2.15 Depth of roots (m) P 1 S Uniform NUREG/CR-6697, Att. C 0.3 Drinking water fraction from ground All water assumed to be B,P 3 D 1 NR NR NR NR water supplied from groundwater Household water fraction from B,P 3 NA ground water (if used)
Livestock water fraction from ground All water assumed to be B,P 3 D 1 NR NR NR NR water supplied from groundwater All water assumed to be Irrigation fraction from ground water B,P 3 D 1 supplied from groundwater NR NR NR NR Wet weight crop yield for Non-Leafy P 2 S Truncated Lognormal - N NUREG/CR-6697, Att. C 0.56 0.48 0.001 0.999 1.75 (kg/m2)
Wet weight crop yield for Leafy NUREG/CR-5512, Vol. 3 P 3 D 2.90 NR NR NR NR (kg/m2) Table 6.87 Wet weight crop yield for Fodder NUREG/CR-5512, Vol. 3 P 3 D 1.90 NR NR NR NR (kg/m2) Table 6.87 NUREG/CR-5512, Vol. 3 Growing Season for Non-Leafy (y) P 3 D 0.246 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Growing Season for Leafy (y) P 3 D 0.123 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Growing Season for Fodder (y) P 3 D 0.082 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Translocation Factor for Non-Leafy P 3 D 0.1 NR NR NR NR Table 6.87 Page 6-132
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median NUREG/CR-5512, Vol. 3 Translocation Factor for Leafy P 3 D 1 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Translocation Factor for Fodder P 3 D 1 NR NR NR NR Table 6.87 Weathering Removal Constant for P 2 S Triangular NUREG/CR-6697, Att. C 5.1 18 84 33 Vegetation (1/y)
NUREG/CR-5512, Vol. 3 Wet Foliar Interception Fraction for P 3 D 0.35 Table 6.87 NR NR NR NR Non-Leafy Wet Foliar Interception Fraction for P 2 D Triangular NUREG/CR-6697, Att. C 0.06 0.67 0.95 0.58 Leafy Wet Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Fodder Table 6.87 Dry Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Non-Leafy Table 6.87 Dry Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Leafy Table 6.87 Dry Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Fodder Table 6.87 Storage times of contaminated foodstuffs (days):
Fruits, non-leafy vegetables, and NUREG/CR-5512, Vol. 3 B 3 D 14 NR NR NR NR grain Table 6.87 NUREG/CR-5512, Vol. 3 Leafy vegetables B 3 D 1 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Milk B 3 D 1 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Table 6.87 (holdup period Meat and poultry B 3 D 1 NR NR NR NR for beef = 20d and poultry
=1 day. Lowest value used)
RESRAD Users Manual Table D.6 Fish B 3 D 7 NR NR NR NR Note: Aquatic pathway inactive RESRAD Users Manual Table D.6 Crustacea and mollusks B 3 D 7 NR NR NR NR Note: Aquatic pathway inactive RESRAD Users Manual Well water B 3 D 1 NR NR NR NR Table D.6 Page 6-133
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median RESRAD Users Manual Surface water B 3 D 1 NR NR NR NR Table D.6 RESRAD Users Manual Livestock fodder B 3 D 45 NR NR NR NR Table D.6 Special Radionuclides (C-14)
C-12 concentration in water (g/cm3) P 3 D NA NA NR NR NR NR C-12 concentration in P 3 D NA NA NR NR NR NR contaminated soil (g/g)
Fraction of vegetation carbon from P 3 D NA NA NR NR NR NR soil Fraction of vegetation carbon from P 3 D NA NA NR NR NR NR air C-14 evasion layer thickness in soil P 2 D NA NA NR NR NR NR (m)
C-14 evasion flux rate from soil P 3 D NA NA NR NR NR NR (1/sec)
C-12 evasion flux rate from soil P 3 D NA NA NR NR NR NR (1/sec)
Fraction of grain in beef cattle feed B 3 D NA NA NR NR NR NR NA Fraction of grain in milk cow feed B 3 D NA NR NR NR NR Dose Conversion Factors (Inhalation mrem/pCi) 2.19E-04 Co-60 M 3 D FGR11 NR NR NR NR 4.62E-05 Cs-134 M 3 D FGR11 NR NR NR NR 3.19E-05 Cs-137 M 3 D FGR11 NR NR NR NR 6.29E-06 Ni-63 M 3 D FGR11 NR NR NR NR 1.30E-03 Sr-90 M 3 D FGR11 NR NR NR NR Dose Conversion Factors (Ingestion mrem/pCi) 2.69E-05 Co-60 M 3 D FGR11 NR NR NR NR 7.33E-05 Cs-134 M 3 D FGR11 NR NR NR NR 5.00E-05 Cs-137 M 3 D FGR11 NR NR NR NR 5.77E-07 Ni-63 M 3 D FGR11 NR NR NR NR Page 6-134
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median 1.42E-04 Sr-90 M 3 D FGR11 NR NR NR NR Plant Transfer Factors (pCi/g plant)/(pCi/g soil)
Lognormal - N Co-60 P 1 S NUREG/CR-6697, Att. C -2.53 0.9 7.9E-02 Lognormal - N Cs-134 P 1 S NUREG/CR-6697, Att. C -3.22 1.0 4.0E-02 Lognormal - N Cs-137 P 1 S NUREG/CR-6697, Att. C -3.22 1.0 4.0E-02 Lognormal - N Ni-63 P 1 S NUREG/CR-6697, Att. C -3.00 0.9 5.0E-02 Lognormal - N Sr-90 P 1 S NUREG/CR-6697, Att. C -1.20 1.0 3.0E-01 Meat Transfer Factors (pCi/kg)/(pCi/d)
Lognormal - N Co-60 P 2 S NUREG/CR-6697, Att. C -3.51 1.0 3.0E-02 Lognormal - N Cs-134 P 2 S NUREG/CR-6697, Att. C -3.00 0.4 5.0E-02 Lognormal - N Cs-137 P 2 S NUREG/CR-6697, Att. C -3.00 0.4 5.0E-02 Lognormal - N Ni-63 P 2 S NUREG/CR-6697, Att. C -5.30 0.9 5.0E-03 Lognormal - N Sr-90 P 2 S NUREG/CR-6697, Att. C -4.61 0.4 1.0E-02 Milk Transfer Factors (pCi/L)/(pCi/d)
Lognormal - N Co-60 P 2 S NUREG/CR-6697, Att. C -6.21 0.7 2.0E-03 Lognormal - N Cs-134 P 2 S NUREG/CR-6697, Att. C -4.61 0.5 1.0E-02 Lognormal - N Cs-137 P 2 S NUREG/CR-6697, Att. C -4.61 0.5 1.0E-02 Lognormal - N Ni-63 P 2 S NUREG/CR-6697, Att. C -3.91 0.7 2.0E-02 Sr-90 Lognormal - N P 2 S NUREG/CR-6697, Att. C -6.21 0.5 2.0E-03 Bioaccumulation Factors for Fish ((pCi/kg)/(pCi/L))
Inactive Co-60 P 2 NA NUREG/CR-6697, Att. C 5.7 1.1 3.0E+02 Page 6-135
RESRAD Input Parameters for ZSRP Soil Uncertainty Analysis Parameter (unit)
Typea Priorityb Treatmentc Value/Distribution Basis Distribution's Statistical Parametersd 1 2 3 4 Mean/
Median Inactive Cs-134 P 2 NA NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Inactive Cs-137 P 2 NA NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Inactive Ni-63 P 2 NA NUREG/CR-6697, Att. C 4.6 1.1 9.9E+01 Inactive Sr-90 P 2 NA NUREG/CR-6697, Att. C 4.1 1.1 6.0E+01 Bioaccumulation Factors for Crustacea/ Mollusks ((pCi/kg)/(pCi/L))
Inactive RESRAD Users Manual Co-60 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Cs-134 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Cs-137 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Ni-63 P 3 NA NR NR NR NR Appendix D Inactive RESRAD Users Manual Sr-90 P 3 NA NR NR NR NR Appendix D 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 Notes:
a P = physical, B = behavioral, M = metabolic; (see NUREG/CR-6697, Attachment B, Table 4.)
b 1 = high-priority parameter, 2 = medium-priority parameter, 3 = low-priority parameter (see NUREG/CR-6697, Attachment B, Table 4.1) c D = deterministic, S = stochastic 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 Beta: 1 = minimum, 2 = maximum, 3 = P-value, 4 = Q-value Triangular: 1 = minimum, 2 = mode, 3 = maximum Uniform: 1 = minimum, 2 = maximum Page 6-136
ZION STATION RESTORATION PROJECT LICENSE TERMINATION PLAN REVISION 1 ATTACHMENT 4 RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Page 6-137
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Soil Concentrations Basic radiation dose limit (mrem/y) 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 (contaminated, unsaturated, and saturated zones) (cm3/g)
Co-60 P 1 D 1161 TSD 14-0042 5.46 2.53 0.001 0.999 235 Cs-134 P 1 D 615 TSD 14-0042 6.1 2.33 0.001 0.999 446 Cs-137 P 1 D 615 TSD 14-004 2 6.1 2.33 0.001 0.999 446 Ni-63 P 1 D 62 TSD 14-0042 6.05 1.46 0.001 0.999 424 Sr-90 P 1 D 2.3 TSD 14-0042 3.45 2.12 0.001 0.999 32 Initial concentration of radionuclides No existing groundwater P 3 D 0 NR NR NR NR present in groundwater (pCi/l) contamination Calculation Times Time since placement of material (y) P 3 D 0 RESRAD Default NR NR NR NR 0, 1, 3, 10, 30, 100, 300, Time for calculations (y) P 3 D RESRAD Default NR NR NR NR 1000 Contaminated Zone Area of the Security Area of contaminated zone (m2) P 2 D 64,500 NR NR NR NR Protected Area on Zion Site Surface Soil Depth = 0.15m Thickness of contaminated zone (m) P 2 D 0.15 or 1.0 NR NR NR NR Subsurface Soil Depth = 1m 287 Diameter of 64,500 m2 Length parallel to aquifer flow (m) P 2 D NR NR NR NR contaminated area.
Does the initial contamination No initial contamination in NA NA NA No NA NA NA NA penetrate the water table? water table Contaminated fraction below water No initial contamination in Pe 3e D 0 NR NR NR NR table water table Cover and Contaminated Zone Hydrological Data Cover depth (m) P 2 D 0 No Cover NR NR NR NR NA Density of cover (g/cm ) 3 P 1 NA NA No Cover NA NA NA NA NA Cover erosion rate (m/y)
P,B 2 NA NA No Cover NA NA NA NA NA Site-specific average native Density of contaminated zone sand and disturbed sand P 1 D 1.8 1.51 0.16 0.001 0.999 1.51 (g/cm3) from Reference 6-21, Table 5.5.
Page 6-138
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Contaminated zone erosion rate Median P,B 2 D 0.0015 5E-08 0.0007 0.005 0.2 0.0015 (m/y) NUREG/CR-6697 Att. C Site-specific average native sand and disturbed sand Contaminated zone total porosity P 2 D 0.35 0.43 0.06 0.001 0.999 0.43 from Reference 6-21, Table 5.6 D 0.066 Site-specific value from Contaminated zone field capacity P 3 NR NR NR NR Reference 6-21, Table 5.4 Contaminated zone hydraulic Site-specific value from P 2 D 2880 786 17000 NA NA 3649 conductivity (m/y) Reference 6-21, Table 5.9 Median 0.97 0.97 Contaminated zone b parameter P 2 D NUREG 6697 distribution -0.0253 0.216 NA NA for site soil type - sand Median Humidity in air (g/m3) P 3 D 7.2 1.98 0.334 0.001 0.999 7.2 NUREG/CR-6697 Att. C D Median Evapotranspiration coefficient P 2 0.625 0.5 0.75 NR NR 0.625 NUREG/CR-6697 Att. C D Median Average annual wind speed (m/s) P 2 4.2 1.445 0.2419 1.4 13 4.2 NUREG/CR-6697 Att. C D Site-specific value from Precipitation (m/y) P 2 0.83 NR NR NR NR Reference 6-21, Table 5.12 D NUREG-5512, Vol. 3, Table Irrigation (m/y) B 3 0.19 NR NR NR NR 6-18 (Illinois Average)
Overhead irrigation is Irrigation mode B 3 D Overhead NR NR NR NR common practice in U. S.
Site-specific value from Runoff coefficient P 2 D 0.2 Reference 6-21, Section 0.1 0.8 NR NR 0.45 5.10 Watershed area for nearby stream P 3 D 1.0E+06 RESRAD Default NR NR NR NR or pond (m2)
Accuracy for water/soil
- 3 D 1.00E-03 RESRAD Default NR NR NR NR computations Saturated Zone Hydrological Data Site-specific average native sand and disturbed sand Density of saturated zone (g/cm3) P 2 D 1.8 1.51 0.16 0.001 0.999 1.52 from Reference 6-21, Table 5.5.
Site-specific average native sand and disturbed sand 0.43 Saturated zone total porosity P 1 D 0.35 0.43 0.0699 0.214 0.646 from Reference 6-21, Table 5.6 Page 6-139
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Site-specific average native sand and disturbed sand Saturated zone effective porosity P 1 D 0.29 0.43 0.06 0.001 0.999 0.43 from Reference 6-21, Table 5.7 0.066 Site-specific value from Saturated zone field capacity P 3 D NR NR NR NR Reference 6-21, Table 5.4 Saturated zone hydraulic Site-specific average from P 1 D 2880 786 17000 NA NA 3649 conductivity (m/y) Reference 6-21, Table 5.9.
Site-specific average native sand and disturbed sand Saturated zone hydraulic gradient P 2 D 0.0039 -5.11 1.77 0.00007 0.5 0.006 from Reference 6-21, Table 5.10 NA saturated zone b not active NUREG/CR-6697, Att. A, NR Saturated zone b parameter P 2 D NR NR NR NR because water table drop Table 2 rate =0 Well pumping rate assumed Water table drop rate (m/y) P 3 D 0 small relative to water table NR NR NR NR volume.
Well pump intake depth (m below Mid-point of Shallow Aquifer P 2 D 3.3 NA NA NA NA water table) Reference 6-21, Table 5.1 Model: Non-dispersion (ND) or P 3 D ND Non-dispersion model used NR NR NR NR Mass-Balance (MB)
Calculated according to method described in NUREG/CR-6697, Att. C Well pumping rate (m3/y) P 2 D 2250 Section 3.10using Illinois NR NR NR NR NR specific irrigation rate and NUREG/CR-5512 vol. 3 livestock water intake rate Unsaturated Zone Hydrological Data Number of unsaturated zone strata P 3 D 1 One unsaturated zone NA NA NA NA Page 6-140
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Distance from ground surface (591) to water table (579) = 3.6 3.45 Reference 6-21, Tables 5.1 (for 0.15 m contaminated and 5.2 zone thickness)
For 0.15 m contaminated Unsat. zone thickness (m) P 1 D 2.6 NA NA NA NA zone thickness unsaturated (for 1.0 m contaminated zone = 3.6 - 0.15 = 3.45 m zone thickness)
For 1.0 m contaminated zone thickness unsaturated zone = 3.6 - 1.0 = 2.6 m Site-specific value from Unsat. zone soil density (g/cm3) P 2 D 1.8 NA NA NA NA Reference 6-21, Table 5.5 Site-specific average native sand and disturbed sand 0.43 Unsat. zone total porosity P 1 D 0.35 0.43 0.0699 0.214 0.646 from Reference 6-21, Table 5.6 Site-specific average native sand and disturbed sand 0.342 Unsat. zone effective porosity P 1 D 0.29 0.342 0.0705 0.124 0.56 from Reference 6-21, Table 5.7 0.066 Site-specific value from Unsat. zone field capacity P 3 D NR NR NR NR Reference 6-21, Table 5.4 Unsat. zone hydraulic conductivity Site-specific average from P 2 D 2880 -0.511 1.77 0.00007 0.5 0.006 (m/y) Reference 6-21, Table 5.9.
Median Unsat. zone soil-specific b P 2 D 0.97 NUREG/CR-6697 Att. C -0.0253 0.216 0.501 1.90 0.97 parameter Sand soil type Occupancy NUREG/CR-5512, Vol. 3 Table 6.29 Inhalation rate (m3/y) M,B 3 D 8400 NR NR NR NR
(=23 m3/d x 365 d/y)
See See See See NUREG- NUREG-Median NUREG- NUREG-Mass loading for inhalation (g/m )
3 P,B 2 D 2.35E-05 6697 6697 2.35E-05 NUREG/CR-6697, Att. C 6697 6697 Table Table 4.6-Table 4.6-1 Table 4.6-1 4.6-1 1 RESRAD Users Manual Exposure duration B 3 D 30 (Parameter not used in dose NR NR NR NR calculation)
Page 6-141
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Median Indoor dust filtration factor P,B 2 D 0.55 0.15 0.95 0.55 NUREG/CR-6697, Att. C 75th Percentile Shielding factor, external gamma P 2 D 0.40 -1.3 0.59 0.044 1 0.272 NUREG/CR-6697, Att. C NUREG/CR-5512, Vol. 3 Fraction of time spent indoors B 3 D 0.649 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Fraction of time spent outdoors (on B 3 D 0.124 Table 6.87 (outdoors + NR NR NR NR site) gardening)
Circular contaminated zone assumed for modeling purposes Shape factor flag, external gamma P 3 D Circular NR NR NR NR Ingestion, Dietary NUREG/CR-5512, Vol. 3 Fruits, non-leafy vegetables, grain M,B 2 D 112 Table 6.87 (other NR NR NR NR consumption (kg/y) vegetables + fruits + grain)
NUREG/CR-5512, Vol. 3 Leafy vegetable consumption (kg/y) M,B 3 D 21.4 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Milk consumption (L/y) M,B 2 D 233 NR NR NR NR Table 6.87 M,B NUREG/CR5512, Vol. 3 Meat and poultry consumption (kg/y) 3 D 65.1 NR NR NR NR Table 6.87 (beef + poultry)
NUREG/CR-5512, Vol. 3 Table 6.87 M,B Fish consumption (kg/y) 3 D 20.6 NR NR NR NR Note: Aquatic Pathway inactive RESRAD Users Manual Table D.2 M,B Other seafood consumption (kg/y) 3 D 0.9 NR NR NR NR Note: Aquatic Pathway inactive M,B NUREG/CR-5512, Vol. 3 Soil ingestion rate (g/y) 2 D 18.3 NR NR NR NR Table 6.87 M,B NUREG/CR-5512, Vol. 3 Drinking water intake (L/y) 2 D 478 NR NR NR NR Table 6.87 Contamination fraction of drinking All water assumed B,P 3 D 1 NR NR NR NR water contaminated Contamination fraction of household B,P 3 NA water (if used)
Contamination fraction of livestock All water assumed B,P 3 D 1 NR NR NR NR water contaminated Page 6-142
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Contamination fraction of irrigation All water assumed B,P 3 D 1 NR NR NR NR water contaminated Assumption that pond is Contamination fraction of aquatic constructed that intercepts B,P 2 D NA NR NR NR NR food contaminated water not credible at Zion site 100% of food consumption Contamination fraction of plant food B,P 3 D 1 NR NR NR NR rate from onsite source 100% of food consumption Contamination fraction of meat B,P 3 D 1 NR NR NR NR rate from onsite source Contamination fraction of milk 100% of food consumption B,P 3 D 1 NR NR NR NR rate from onsite source Ingestion, Non-Dietary NUREG/CR5512, Vol. 3 Livestock fodder intake for meat Table 6.87 (forage, grain M 3 D 28.3 NR NR NR NR (kg/day) and hay for beef cattle +
poultry + layer hen)
NUREG/CR5512, Vol. 3 Livestock fodder intake for milk M 3 D 65.2 Table 6.87 (forage + grain + NR NR NR NR (kg/day) hay)
NUREG/CR5512, Vol. 3 Livestock water intake for meat M 3 D 50.6 Table 6.87 (beef cattle + NR NR NR NR (L/day) poultry + layer hen)
Livestock water intake for milk NUREG/CR5512, Vol. 3 M 3 D 60 NR NR NR NR (L/day) Table 6.87 RESRAD Users Manual, Livestock soil intake (kg/day) M 3 D 0.5 NR NR NR NR Appendix L Mass loading for foliar deposition NUREG/CR-5512, Vol. 3 P 3 D 4.00E-04 NR NR NR NR (g/m3) Table 6.87, gardening 25th Percentile 0.15 for Surface Soil NUREG/CR-6697, Att. C Depth of soil mixing layer (m) P 2 D 0 0.15 0.6 0.23 Median 0.23 for Subsurface Soil NUREG/CR-6697, Att. C 25th Percentile 4.0 2.15 Depth of roots (m) P 1 D 1.22 0.3 NUREG/CR-6697, Att. C Drinking water fraction from ground All water assumed to be B,P 3 D 1 NR NR NR NR water supplied from groundwater Household water fraction from B,P 3 NA ground water (if used)
Livestock water fraction from ground All water assumed to be B,P 3 D 1 NR NR NR NR water supplied from groundwater Page 6-143
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median All water assumed to be Irrigation fraction from ground water B,P 3 D 1 supplied from groundwater NR NR NR NR Wet weight crop yield for Non-Leafy Median P 2 D 1.75 0.56 0.48 0.001 0.999 1.75 (kg/m2) NUREG/CR-6697, Att. C Wet weight crop yield for Leafy NUREG/CR-5512, Vol. 3 P 3 D 2.90 NR NR NR NR (kg/m2) Table 6.87 NUREG/CR-5512, Vol. 3 Wet weight crop yield for Fodder P 3 D 1.90 Table 6.87 (maximum of NR NR NR NR (kg/m2) forage, grain and hay)
NUREG/CR-5512, Vol. 3 Growing Season for Non-Leafy (y) P 3 D 0.246 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Growing Season for Leafy (y) P 3 D 0.123 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Growing Season for Fodder (y) P 3 D 0.082 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Translocation Factor for Non-Leafy P 3 D 0.1 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Translocation Factor for Leafy P 3 D 1 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Translocation Factor for Fodder P 3 D 1 NR NR NR NR Table 6.87 Weathering Removal Constant for Median P 2 D 33 5.1 18 84 33 Vegetation (1/y) NUREG/CR-6697, Att. C Wet Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Non-Leafy Table 6.87 Wet Foliar Interception Fraction for Median P 2 D 0.58 0.06 0.67 0.95 0.58 Leafy NUREG/CR-6697, Att. C Wet Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Fodder Table 6.87 Dry Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Non-Leafy Table 6.87 Dry Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Leafy Table 6.87 Dry Foliar Interception Fraction for NUREG/CR-5512, Vol. 3 P 3 D 0.35 NR NR NR NR Fodder Table 6.87 Storage times of contaminated foodstuffs (days):
Fruits, non-leafy vegetables, and NUREG/CR-5512, Vol. 3 B 3 D 14 NR NR NR NR grain Table 6.87 NUREG/CR-5512, Vol. 3 Leafy vegetables B 3 D 1 NR NR NR NR Table 6.87 NUREG/CR-5512, Vol. 3 Milk B 3 D 1 NR NR NR NR Table 6.87 Page 6-144
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median NUREG/CR-5512, Vol. 3 Table 6.87 (holdup period Meat and poultry B 3 D 1 NR NR NR NR for beef = 20d and poultry
=1 day. Lowest value used)
RESRAD Users Manual Table D.6 Fish B 3 D 7 NR NR NR NR Note: Aquatic pathway inactive in BFM RESRAD Users Manual Table D.6 Crustacea and mollusks B 3 D 7 NR NR NR NR Note: Aquatic pathway inactive in BFM RESRAD Users Manual Well water B 3 D 1 NR NR NR NR Table D.6 RESRAD Users Manual Surface water B 3 D 1 NR NR NR NR Table D.6 RESRAD Users Manual Livestock fodder B 3 D 45 NR NR NR NR Table D.6 Special Radionuclides (C-14)
C-12 concentration in water (g/cm3) P 3 D NA NA NR NR NR NR C-12 concentration in P 3 D NA NA NR NR NR NR contaminated soil (g/g)
Fraction of vegetation carbon from P 3 D NA NA NR NR NR NR soil Fraction of vegetation carbon from P 3 D NA NA NR NR NR NR air C-14 evasion layer thickness in soil P 2 D NA NA NR NR NR NR (m)
C-14 evasion flux rate from soil P 3 D NA NA NR NR NR NR (1/sec)
C-12 evasion flux rate from soil P 3 D NA NA NR NR NR NR (1/sec)
Fraction of grain in beef cattle feed B 3 D NA NA NR NR NR NR NA Fraction of grain in milk cow feed B 3 D NA NR NR NR NR Dose Conversion Factors (Inhalation mrem/pCi) 2.19E-04 Co-60 M 3 D FGR11 NR NR NR NR Cs-134 M 3 D 4.62E-05 FGR11 NR NR NR NR Cs-137 M 3 D 3.19E-05 FGR11 NR NR NR NR Page 6-145
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median Ni-63 M 3 D 6.29E-06 FGR11 NR NR NR NR Sr-90 M 3 D 1.30E-03 FGR11 NR NR NR NR Dose Conversion Factors (Ingestion mrem/pCi)
Co-60 M 3 D 2.69E-05 FGR11 NR NR NR NR Cs-134 M 3 D 7.33E-05 FGR11 NR NR NR NR Cs-137 M 3 D 5.00E-05 FGR11 NR NR NR NR Ni-63 M 3 D 5.77E-07 FGR11 NR NR NR NR Sr-90 M 3 D 1.42E-04 FGR11 NR NR NR NR Plant Transfer Factors (pCi/g plant)/(pCi/g soil) 1.5E-01 75th Percentile Co-60 P 1 D -2.53 0.9 7.9E-02 NUREG/CR-6697, Att. C 7.8E-02 75th Percentile Cs-134 P 1 D -3.22 1.0 4.0E-02 NUREG/CR-6697, Att. C 7.8E-02 75th Percentile Cs-137 P 1 D -3.22 1.0 4.0E-02 NUREG/CR-6697, Att. C 9.2E-02 75th Percentile Ni-63 P 1 D -3.00 0.9 5.0E-02 NUREG/CR-6697, Att. C 5.9E-01 75th Percentile Sr-90 P 1 D -1.20 1.0 3.0E-01 NUREG/CR-6697, Att. C Meat Transfer Factors (pCi/kg)/(pCi/d) 5.8E-02 75th Percentile Co-60 P 2 D -3.51 1.0 3.0E-02 NUREG/CR-6697, Att. C 6.5E-02 75th Percentile Cs-134 P 2 D -3.00 0.4 5.0E-02 NUREG/CR-6697, Att. C 6.5E-02 75th Percentile Cs-137 P 2 D -3.00 0.4 5.0E-02 NUREG/CR-6697, Att. C 5E-03 Median Ni-63 P 2 D -5.30 0.9 5.0E-03 NUREG/CR-6697, Att. C Median Sr-90 P 2 D 8E-03 -4.61 0.4 1.0E-02 NUREG/CR-6697, Att. C Milk Transfer Factors (pCi/L)/(pCi/d)
Median Co-60 P 2 D 2E-03 -6.21 0.7 2.0E-03 NUREG/CR-6697, Att. C 1.4E-02 75th Percentile Cs-134 P 2 D -4.61 0.5 1.0E-02 NUREG/CR-6697, Att. C 1.4E-02 75th Percentile Cs-137 P 2 D -4.61 0.5 1.0E-02 NUREG/CR-6697, Att. C 3.2E-02 75th Percentile Ni-63 P 2 D -3.91 0.7 2.0E-02 NUREG/CR-6697, Att. C Page 6-146
RESRAD Input Parameters for ZSRP Surface Soil and Subsurface Soil DCGL Parameter (unit) Typea Priorityb Treatmentc Value Basis Distribution's Statistical Parametersd Mean/
1 2 3 4 Median 2.7E-03 75th Percentile Sr-90 P 2 D -6.21 0.5 2.0E-03 NUREG/CR-6697, Att. C Bioaccumulation Factors for Fish ((pCi/kg)/(pCi/L))
Co-60 P 2 NA Inactive NUREG/CR-6697, Att. C 5.7 1.1 3.0E+02 Cs-134 P 2 NA Inactive NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Cs-137 P 2 NA Inactive NUREG/CR-6697, Att. C 7.6 0.7 2.0E+03 Ni-63 P 2 NA Inactive NUREG/CR-6697, Att. C 4.6 1.1 9.9E+01 Sr-90 P 2 NA Inactive NUREG/CR-6697, Att. C 4.1 1.1 6.0E+01 Bioaccumulation Factors for Crustacea/ Mollusks ((pCi/kg)/(pCi/L))
RESRAD Users Manual Co-60 P 3 NA Inactive NR NR NR NR Appendix D RESRAD Users Manual Cs-134 P 3 NA Inactive NR NR NR NR Appendix D RESRAD Users Manual Cs-137 P 3 NA Inactive NR NR NR NR Appendix D RESRAD Users Manual Ni-63 P 3 NA Inactive NR NR NR NR Appendix D RESRAD Users Manual Sr-90 P 3 NA Inactive NR NR NR NR Appendix D 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 Notes: a P = physical, B = behavioral, M = metabolic; (see NUREG/CR-6697, Attachment B, Table 4.)
b 1 = high-priority parameter, 2 = medium-priority parameter, 3 = low-priority parameter (see NUREG/CR-6697, Attachment B, Table 4.1) c D = deterministic, S = stochastic 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 Beta: 1 = minimum, 2 = maximum, 3 = P-value, 4 = Q-value Triangular: 1 = minimum, 2 = mode, 3 = maximum Uniform: 1 = minimum, 2 = maximum Page 6-147