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