Text

Final Status Survey Final Report - Phase 4 Fssr Rev. 2
	ML22279A986
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	09/30/2022
From:	Yetter R; ZionSolutions
To:	; Office of Nuclear Material Safety and Safeguards
Shared Package
ML22279A984	List: ML22279A985; ML22279A986; ML22279A987; ML22279A988; ML22279A989; ML22279A990; ML22279A991; ML22279A993;
References
	ZS-2022-043
	Download: ML22279A986 (96)
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-H ZION STATION RESTORATION PROJECT FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 SEPTEMBER 2022

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Summary of Changes in this Revision: Revision 2 - Revised where necessary to address the reperformance of FSS in survey units 12201C, 12201D, 12201E, 12203A, and 12205A.

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FINAL STATUS SURVEY FINAL REPORT PHASE 4 Revision 2 Prepared By: R Yetter III Date:

LT/FSS QA/Documentation Specialist Reviewed By: R Yetter Date:

Director Radiological Site Closure Approved By: S Roberts Date:

SVP Radiological Programs 3

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 TABLE OF CONTENTS 1 Introduction ........................................................................................................................... 10 1.1 Executive Summary ....................................................................................................... 10 1.2 Phased Submittal Approach ........................................................................................... 14 2 Final Status Survey Program Overview ................................................................................ 15 2.1 Survey Planning ............................................................................................................. 15 2.2 Survey Design ................................................................................................................ 22 2.3 Survey Implementation .................................................................................................. 25 2.4 Survey Data Assessment ................................................................................................ 26 2.5 Quality Assurance and Quality Control Measures ......................................................... 26 3 Site Information .................................................................................................................... 27 3.1 Site Description .............................................................................................................. 27 3.2 Survey Unit Description ................................................................................................. 30 3.3 Summary of Historical Radiological Data ..................................................................... 44 3.4 Conditions at the Time of Final Status Survey .............................................................. 51 3.5 Identification of Potential Contaminants........................................................................ 52 3.6 Radiological Release Criteria ......................................................................................... 53 4 Final Status Survey Protocol ................................................................................................. 53 4.1 Data Quality Objectives ................................................................................................. 53 4.2 Survey Unit Designation and Classification .................................................................. 59 4.3 Background Determination ............................................................................................ 59 4.4 Final Status Survey Sample Plans .................................................................................. 59 4.5 Survey Design ................................................................................................................ 60 4.5.1 Determination of Number of Data Points ............................................................... 60 4.5.2 Sample Locations .................................................................................................... 63 4.6 Instrumentation............................................................................................................... 63 4.6.1 Detector Efficiencies ............................................................................................... 63 4.6.2 Detector Sensitivities .............................................................................................. 64 4.6.3 Instrument Maintenance and Control...................................................................... 64 4.6.4 Instrument Calibration ............................................................................................ 64 4.7 Survey Methodology ...................................................................................................... 65 4

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 4.7.1 Scan Surveys ........................................................................................................... 65 4.7.2 Soil Sampling .......................................................................................................... 65 4.8 Quality Control Surveys ................................................................................................. 66 5 Survey Findings .................................................................................................................... 66 5.1 Survey Data Conversion................................................................................................. 67 5.2 Survey Data Verification and Validation ....................................................................... 71 5.3 Anomalous Data/Elevated Scan Results and Investigation ........................................... 72 5.4 Evaluation of Number of Sample/Measurement Locations in Survey Units ................. 88 5.5 Comparison of Findings with Derived Concentration Guideline Levels ....................... 89 5.6 Description of ALARA to Achieve Final Activity Levels ............................................. 91 5.7 NRC/Independent Verification Team Findings ............................................................. 92 6 Summary ............................................................................................................................... 92 7 References ............................................................................................................................. 93 8 Appendices ............................................................................................................................ 95 5

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 LIST OF TABLES Table 1-1, Phase 4 Survey Units .................................................................................................................................. 11 Table 2-1, Base Case and Operational DCGLs for Surface Soils(1) ............................................................................. 20 Table 2-2, Base Case and Operational DCGLs for Subsurface Soils(1) ....................................................................... 20 Table 2-3, Typical Final Status Survey Unit Areas ..................................................................................................... 21 Table 2-4, Dose Significant Radionuclides and Mixture(1) .......................................................................................... 23 Figure 3-1, Zion Nuclear Power Station Owner Controlled Area ............................................................................... 28 Figure 3-2, Zion Nuclear Power Station Radiologically Restricted Area .................................................................... 29 Figure 3-3, Fuel Handling Building (FHB) and Car Shed Excavation Survey Units .................................................. 47 Figure 3-4, Demolition of Containment Domes .......................................................................................................... 48 Figure 3-5, Remediation of Indigenous Soils Following Removal of Sacrificial Soil Barrier .................................... 49 Figure 3-6, Phase 4 Open Land Areas Prepared for FSS ............................................................................................. 52 Table 4-3, Recommended Scan Coverage ................................................................................................................... 59 Table 5-1, Basic Statistical Properties for FSS of Phase 4 Open Land Survey Units .................................................. 68 Table 5-2, Mean Base Case SOF and Dose Contribution from Soil ............................................................................ 90 LIST OF FIGURES Figure 1-1, Phase 4 Survey Unit Locations ................................................................................................................. 13 Figure 2-1, Characterization/License Termination Group Organizational Chart......................................................... 17 Figure 3-1, Zion Nuclear Power Station Owner Controlled Area ............................................................................... 28 Figure 3-2, Zion Nuclear Power Station Radiologically Restricted Area .................................................................... 29 Figure 3-3, Fuel Handling Building (FHB) and Car Shed Excavation Survey Units .................................................. 47 Figure 3-4, Demolition of Containment Domes .......................................................................................................... 48 Figure 3-5, Remediation of Indigenous Soils Following Removal of Sacrificial Soil Barrier .................................... 49 Figure 3-6, Phase 4 Open Land Areas Prepared for FSS ............................................................................................. 52 6

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 LIST OF ACRONYMS AND ABBREVIATIONS ALARA As Low As Reasonably Achievable AMCG Average Member of the Critical Group ASP Alarm Set Point BcDCGL Base Case Derived Concentration Guideline Level BcSOF Base Case Sum of Fractions CCDD Clean Concrete Demolition Debris CAD Computer Aided Design CAP Corrective Action Program C/LT Characterization/License Termination ComEd Commonwealth Edison Company DCGL Derived Concentration Guideline Level DSAR Defueled Safety Analysis Report DQA Data Quality Assessment DQO Data Quality Objective DRP Discrete Radioactive Particle EMC Elevated Measurement Comparison ESCSG EnergySolutions Commercial Services Group ETD Easy-to-Detect FSS Final Status Survey FSSR Final Status Survey Final Report GPS Global Positioning System HSA Historical Site Assessment HTD Hard-to-Detect HPGe High-Purity Germanium IEMA Illinois Environmental Management Agency ISFSI Independent Spent Fuel Storage Installation LBGR Lower Bound of the Gray Region LTP License Termination Plan 7

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 MARSSIM Multi-Agency Radiation Survey and Site Investigation Manual MDC Minimum Detectable Concentration MDCR Minimum Detectable Count Rate NAD North American Datum NaI Sodium Iodide NIST National Institute of Standards and Technology NRC Nuclear Regulatory Commission ODCM Offsite Dose Calculation Manual OpDCGL Operational Derived Concentration Guideline Level OpSOF Operational Sum of Fractions ORISE Oak Ridge Institute for Science and Education PNNL Pacific Northwest National Laboratory PSDAR Post Shutdown Decommissioning Activities Report PWST Primary Water Storage Tank QA Quality Assurance QAPP Quality Assurance Project Plan QC Quality Control RAI Request for Additional Information RCA Radiologically Controlled Area RE Radiological Engineer ROC Radionuclides of Concern SFP Spent Fuel Pool SOF Sum of Fractions SSC Systems, structures and components SST Secondary Storage Tank TEDE Total Effective Dose Equivalent TSD Technical Support Document UBGR Upper Bound of the Gray Region UCL Upper Confidence Level 8

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 VCC Vertical Concrete Cask VSP Visual Sample Plan ZSRP Zion Station Restoration Project ZNPS Zion Nuclear Power Station 9

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 1 Introduction 1.1 Executive Summary The purpose of this Phase 4 Final Status Survey (FSS) Final Report is to provide a summary of the survey results and overall conclusions which demonstrate that the Zion Nuclear Power Station (ZNPS) facility, or portions of the site, meets the 25 mrem/year release criterion as established in Nuclear Regulatory Commission (NRC) Regulation 10CFR20.1402 Radiological Criteria for Unrestricted Use. This report is the final phased submittal for the Zion Station Restoration Project (ZSRP). This Phase 4 FSS Report (FSSR) was written in accordance with Section 5.11 of Chapter 5 of the ZSRP License Termination Plan (LTP)

(Reference 1).

This Phase 4 FSSR focuses on the balance of the impacted open land surface area and subsurface soils. The FSS results provided herein assess and summarize that any residual radioactivity remaining in the survey units addressed by this Phase 4 FSSR results in a Total Effective Dose Equivalent (TEDE) to an average member of the critical group (AMCG) that does not exceed 25 mrem/year and that the residual radioactivity has been reduced to levels that are As Low As Reasonably Achievable (ALARA). The release criterion is translated into site-specific Derived Concentration Guideline Levels (DCGLs) for assessment and summary.

This report documents that FSS activities were performed consistent with the guidance provided in the ZSRP LTP; NUREG-1575, Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) (Reference 2); ZS-LT-01, Quality Assurance Project Plan (for Characterization and FSS) (QAPP) (Reference 3); ZS-LT-300-001-001, Final Status Survey Package Development (Reference 4); ZS-LT-300-001-003, Isolation and Control for Final Status Survey (Reference 5); ZS-LT-300-001-004, Final Status Survey Data Assessment (Reference 6); as well as various other station implementing procedures.

This Phase 4 FSSR has been written consistent with the guidance provided in NUREG-1757, Vol. 2, Consolidated Decommissioning Guidance; Characterization, Survey, and Determination of Radiological Criteria (Reference 7); MARSSIM; and the requirements specified in ZS-LT-300-001-005, Final Status Survey Data Reporting (Reference 8).

To facilitate the data management process, FSSRs incorporate Release Records from the FSS of multiple survey units. Release Records are complete and unambiguous records of the as-left radiological status of each specific survey unit. Each Release Record contains sufficient information necessary to perform an independent review and evaluation of both the survey activities, the analytical results and the final conclusion.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 This Phase 4 FSSR specifically addresses sixty-seven (67) open land area survey units that total approximately 178,182 m2 in area. Sixty (60) of the sixty-seven (67) open land survey units included in the Phase 4 report are classified as MARSSIM Class 1 survey units. Six (6) survey units are classified as Class 2, and one (1) survey unit is classified as Class 3.

Table 1-1 provides a listing of all the survey units addressed in this report, along with their classifications and size. Figure 1-1 depicts the locations of the Phase 4 survey units in relation to the ZNPS site as well as survey unit boundaries.

Table 1-1, Phase 4 Survey Units Survey Size Survey Size Name Class Name Class Unit (m2) Unit (m2)

Construction Parking 10203A East Training Area 1 1,999 10214E 1 1,989 Area Construction Parking 10203B East Training Area 1 1,977 10214F 1 1,661 Area SE Corner of Exclusion 10203C East Training Area 1 1,871 10220A 1 2,025 Area - Lakeshore SE Corner of Exclusion 10203F East Training Area 1 1,888 10220H 1 2,088 Area - Lakeshore SE Corner of Exclusion 10204A North Gate Area 1 2,231 10220I 1 2,060 Area - Lakeshore South of Protected Area -

10204B North Gate Area 1 1,549 10221A 1 1,976 Inland South of Protected Area -

10204C North Gate Area 1 1,547 10221C 1 1,959 Inland South of Protected Area -

10204D North Gate Area 1 1,545 10221D 1 1,697 Inland Station Construction North Half of Unit 2 10206A 1 2,844 12104 1 1,940 Area Containment Station Construction South Half of Unit 2 10206B 1 1,837 12105 1 1,938 Area Containment Station Construction North Half of Fuel &

10206C 1 1,833 12106 1 1,936 Area Auxiliary Buildings Station Construction South Half of Fuel &

10206D 1 1,829 12107 1 1,934 Area Auxiliary Buildings Station Construction North Half of Unit 1 10206E 1 1,825 12108 1 1,933 Area Containment South Half of Unit 1 10207A North Warehouse Area 1 2,675 12109 1 1,931 Containment Yard Between Unit 1 10207B North Warehouse Area 1 1,736 12110 1 1,740 Containment and Turbine South Yard Area 10207C North Warehouse Area 1 1,735 12111 1 1,964 Northeast of Gate House North Protected Area 10207D North Warehouse Area 1 1,733 12201A 1 1,992 Yard North Protected Area 10207E North Warehouse Area 1 1,731 12201B 1 1,995 Yard North Protected Area 10208A South Warehouse Area 1 2,460 12201C 1 1,968 Yard 11

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 1-1 (continued), Phase 4 Survey Units Survey Size Survey Size Name Class Name Class Unit (m2) Unit (m2)

North Protected Area 10208B South Warehouse Area 1 1,835 12201D 1 1,842 Yard North Protected Area 10208C South Warehouse Area 1 1,868 12201E 1 1,902 Yard Gate House and 10208D South Warehouse Area 1 1,827 12202A 1 1,998 Southwest Yard Restricted Area South of Gate House and 10209C 1 1,970 12202B 1 1,999 Gate House Southwest Yard NE Corner of Exclusion Gate House and 10212A 2 9,550 12202C 1 1,894 Area - Lakeshore Southwest Yard Gate House and 10212B VCC Construction Area 3 16,154 12202D 1 1,663 Southwest Yard NE Corner of Exclusion Gate House and 10212C 1 1,744 12202E 1 1,845 Area - Lakeshore Southwest Yard NE Corner of Exclusion Gate House and 10212D 1 1,490 12202F 1 1,858 Area - Lakeshore Southwest Yard NE Corner of Exclusion Under Service Building 10213A 2 5,730 12203A 1 1,988 Area and Southeast Yard NE Corner of Exclusion Area Under the Turbine 10213B 1 1,994 12205A 1 1,809 Area Building NE Corner of Exclusion Area Under the Turbine 10213C 1 1,934 12205B 1 1,814 Area Building Construction Parking Area Under the Turbine 10214A 2 8,542 12205C 1 1,818 Area Building Construction Parking Area Under the Turbine 10214B 2 7,372 12205D 1 1,821 Area Building Construction Parking Area Under the Turbine 10214C 2 7,579 12205E 1 1,825 Area Building Construction Parking 10214D 2 8,946 Area All FSS activities essential to data quality have been implemented and performed under approved procedures. Trained individuals, using properly calibrated instruments and laboratory equipment, that are sensitive to the Radionuclides of Concern (ROC), performed the FSS of the Phase 4 survey units in accordance with the LTP and approved procedures.

The survey data for all Phase 4 survey units demonstrate that the dose (TEDE) from residual radioactivity is less than the maximum annual dose (TEDE) which corresponds to the release criterion for license termination for unrestricted use specified in 10CFR20.1402, and support the release of these areas from the 10CFR50 license. Additionally, the ALARA requirement of 10CFR20.1402 has been satisfied.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 1-2, Phase 4 Survey Unit Locations 13

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 1.2 Phased Submittal Approach To minimize the incorporation of redundant historical assessments and other FSS program information, and to facilitate potential phased releases from the current license, FSSRs were prepared in a phased approach. A total of five (5) FSSRs, including this Phase 4 submittal, were generated and submitted to the NRC during the decommissioning project.

Release of Non-Impacted Open Lands On August 27, 2015, ZionSolutions submitted a request (ZS-2015-0134) to release a portion of the ZNPS site from the 10CFR50 licenses (DPR-39 and DPR-48) in accordance with 10CFR50.83, Release of Part of a Power Reactor Facility or Site for Unrestricted Use, and 10CFR100, Reactor Site Criteria. Specifically, a report was generated for the request that addresses the release of eleven (11) non-impacted open land areas from the 10CFR50 licenses. The report contained a summary of the final assessment performed as well as a summary of the characterization surveys performed of these non-impacted survey units.

ZionSolutions reviewed and assessed the subject property to ensure that the radiological condition of these land areas will have no adverse impact on the ability of the site, in aggregate, to meet the 10CFR20, Subpart E, Radiological Criteria for License Termination. The submitted report was not captured as a Phased Submittal with a FSSR because the survey units incorporated within the report were classified as non-impacted. As such, no statistical tests, scan measurements, static measurements, or elevated measurement comparisons were required. The release of the non-impacted areas from the license(s) was approved by the NRC on March 31, 2016.

Phase 1 Final Status Survey Report The Phase 1 FSSR was initially submitted to the NRC on November 1, 2018. The Phase 1 FSSR and the accompanying Release Records addressed the FSS of ten (10) Class 3 open land survey units at Zion. During the review of the Phase 1 FSSR, the NRC identified several quality mistakes which prompted ZionSolutions to withdraw the report until corrections were made. The required corrections were made and the Phase 1 FSSR was resubmitted to the NRC as Revision 1, minus two (2) of the original ten (10) survey units which were included in a subsequent FSSR due to the discovery of additional commodities that required removal.

On October 9, 2019, the NRC stated that the FSSR was sufficient to demonstrate that the surveys performed of seven (7) of the eight (8) Class 3 open land survey units were acceptable to support release of those survey units for unrestricted release. During the review of the revised report, the NRC Staff identified that the results from survey unit 10223 should have triggered the licensees commitment to assess subsurface residual radioactivity. By letter dated March 03, 2020, ZionSolutions submitted revision 2 of the release record for survey unit 10223 and the Phase 1 FSS Final Report. The submittal documented the results of the investigation that was completed in survey unit 10223, with regard to subsurface residual radioactivity.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Phase 2, Part 1 Final Status Survey Report The Phase 2, Part 1 FSSR, submitted to the NRC in March of 2019, contained the FSS units that encompassed the basement structures including the Unit 1 and Unit 2 Containments, the Spent Fuel Pool (SFP)/Transfer Canal, the Auxiliary Building, the Crib House/Forebay, the Waste Water Treatment Facility (WWTF) and the Turbine Building. As a result of a Condition Report regarding mistakes identified by the NRC in their review of the Phase 1 FSSR, the submittal of the Phase 2, Part 1 FSSR was withdrawn. On September 30, 2019, the revised Phase 2, Part 1 FSSR was submitted to the NRC.

Phase 2, Part 2 Final Status Survey Report The Phase 2, Part 2 FSSR and all pertinent Release Records were submitted to the NRC on November 25, 2019. The Phase 2, Part 2 FSSR contained the FSS units that encompassed buried pipe.

Phase 3 Final Status Survey Report The Phase 3 FSSR and all pertinent Release Records were submitted to the NRC on December 30, 2019. The Phase 3 FSSR addressed forty-one (41) Class 1 open land area survey units that totaled approximately 73,546 m2 in area.

2 Final Status Survey Program Overview The FSS Program consists of the methods used in planning, designing, conducting, and evaluating FSS at the ZNPS site to demonstrate that the premises are suitable for release in accordance with the criteria for decommissioning in Title 10CFR20, Subpart E. Final Status Surveys serve as the key action necessary to demonstrate that the TEDE to an AMCG from residual radioactivity does not exceed 25 mrem/year, and that all residual radioactivity at the site is reduced to levels that are ALARA.

To implement the FSS Program, ZionSolutions established the Characterization/License Termination (C/LT) Group, within the Radiation Protection division, with sufficient management and technical resources to fulfill project objectives. The C/LT Group was responsible for the safe completion of all surveys related to characterization, FSS, and final site closure. Approved site procedures and detailed technical support documents (TSD) were written to support the FSS process to ensure consistent implementation and adherence to applicable requirements. Figure 2-1 provides an organizational chart of the C/LT Group.

2.1 Survey Planning Following the cessation of commercial operation, the FSS planning phase was initiated in 1999 by the development of the Zion Station Historical Site Assessment (HSA) (Reference

9) and characterization process. The characterization process was iterative, and continued in 15

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 some cases up to the time of completing FSS. The HSA consisted of a review of site historical records regarding plant incidents, radiological survey documents, and routine and special reports submitted by Exelon Nuclear Generation, LLC (Exelon) to various regulatory agencies. Along with these assessments, interviews with current and past site personnel, reviews of historical site photos, and extensive area inspections were performed to meet the following objectives:

Develop the information necessary to support FSS design, including the development of Data Quality Objectives (DQO) and survey instrument performance standards,

Develop the initial radiological information to support decommissioning planning, including building decontamination, demolition, and waste disposal,

Identify any unique radiological or health and safety issues associated with decommissioning,

Identify the potential and known sources of radioactive contamination in systems, surface or subsurface soils, groundwater, and on structures,

Divide the ZNPS site into manageable areas or units for survey and classification purposes, and

Determine the initial classification of each survey area or unit as non-impacted or impacted. Impacted survey units are classified as Class 1, 2, or 3 as defined in MARSSIM.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 2-1, Characterization/License Termination Group Organizational Chart Senior Vice President &

General Manager Quality Assurance Manager VP -

Environmental Safety & Health Characterization/

LTP Manager Radiological Radiological Engineer Radiation Protection Engineer (LTP (Characterization/Final Instrumentation & Laboratory Lead) Status Survey Lead) Organization Support

- Radiological Instrument Supervisor

-Radiochemist

-Count Room Technician Characterization/ -Instrument Technician Radiological FSS Engineer/

Engineer Supervisors Characterization/

FSS Technicians 17

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Data Quality Objectives (DQO) are qualitative and quantitative statements derived from the DQO process. They clarify technical and quality objectives, define the appropriate type of data, and specify the tolerable levels or potential decision errors used as the basis for establishing the quality and quantity of data required to support inference and decisions. This process, described in MARSSIM and procedure ZS-LT-300-001-001, Final Status Survey Package Development, is a series of graded planning steps found to be effective in establishing criteria for data quality and guiding the development of FSS Sample Plans. The DQOs developed and implemented during the initial phase of site closure planning directed data collection efforts.

The DQO approach consists of the following seven steps:

1. State the Problem - This step provides a clear description of the problem, identification of planning team members (especially the decision makers), a conceptual model of the hazard to be investigated, and the estimated resources required to perform the survey.

The problem associated with FSS is to determine whether a given survey unit meets the radiological release criterion of 10CFR20.1402.

2. Identify the Decision - This step consists of developing a decision statement based on a principal study question (i.e., the stated problem) and determining alternative actions that may be taken based on the answer to the principle study question. Alternative actions identify the measures to resolve the problem. The decision statement combines the principal study question and alternative actions into an expression of choice among multiple actions. For the FSS, the principal study question is: Does residual radioactive contamination present in the survey unit exceed the established DCGL values? The alternative actions may include no action, investigation, resurvey, remediation, and reclassification.

3. Identify Inputs to the Decision - The information required depends on the type of media under consideration (e.g., soil, water, concrete) and whether existing data are sufficient or new data are needed to make the decision. If the decision can be based on existing data, then the source(s) will be documented and evaluated to ensure reasonable confidence that the data is acceptable. If new data is needed, then the type of measurement (e.g., scan, direct measurement, and/or sampling) is determined.

4. Define the Study Boundaries - This step includes identification of the target population of interest, the spatial and temporal features of that population, the time frame for collecting the data, practical constraints, and the scale of decision making. In FSS, the target population is the set of samples or direct measurements that constitute an area of interest. The medium of interest is specified during the planning process. The spatial boundaries include the entire area of interest, including soil depth, area dimensions, contained water bodies, and natural boundaries. Temporal boundaries include activities impacted by time-related events including weather conditions, season, operation of equipment under different environmental conditions, resource loading, and work schedule.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2

5. Develop a Decision Rule - This step develops the binary statement that defines a logical process for choosing among alternative actions. The decision rule is a clear statement using the If...then... format and includes action level conditions and the statistical parameter of interest.

6. Specify Tolerable Limits on Decision Errors - This step incorporates hypothesis testing and probabilistic sampling distributions to control the decision errors during data analysis. Hypothesis testing is a process based on the scientific method that compares a baseline condition (the null hypothesis) to an alternative condition (the alternative hypothesis). Hypothesis testing rests on the premise that the null hypothesis is true and that sufficient evidence must be provided to reject it.

7. Optimize the Design for Obtaining Data - The final step in the DQO process leads to the development of an adequate survey design. By using an on-site analytical laboratory, sampling and analysis processes are designed to provide near real-time data assessment during implementation of field activities and FSS. Gamma scans provide information on soil areas that have residual radioactivity greater than background and allow appropriate selection of biased sampling and measurement locations. This data will be evaluated and used to refine the scope of field activities to optimize implementation of the FSS design and ensure the DQOs are met.

As stated, the primary objective of the DQO process was to demonstrate that the level of residual radioactivity found in the soils in the land area survey units, including any areas of elevated activity, was equal to or below the site-specific DCGLs that correspond to the 25 mrem/year release criterion.

The LTP defines surface soil as in the soil layer within 0.15-m depth from the surface. The LTP defines subsurface soil as the soil layer from 0.15-m to 1-m depth of soil from the surface. Site-specific DCGLs were calculated for both the surface and subsurface soils.

Based on characterization data and historical information (LTP Chapter 5, Section 5.2.3),

there are no expectations of encountering a source term geometry that is comprised of a clean surface layer of soil over a contaminated subsurface soil layer. ZionSolutions TSD-14-011, Soil Area Factors (Reference 10) and LTP Chapter 6, Section 6.8, provide the exposure scenarios and modeling parameters that were used to calculate the site-specific DCGLs for soils (referred to as Base Case Soil DCGLs).

Each radionuclide-specific Base Case DCGL (BcDCGL) is equivalent to the level of residual radioactivity (above background levels) that could, when considered independently, result in a TEDE of 25 mrem/year to an AMCG. To ensure that the summation of dose from each source term is 25 mrem/year or less after all FSS is completed, the BcDCGLs were reduced based on an expected, or a priori, fraction of the 25 mrem/year dose limit from each source term. These reduced values were designated as Operational DCGLs (LTP Chapter 5, Section 5.2.4), and these Operational DCGLs (OpDCGL) were then used as the DCGL for the FSS design of the survey unit (calculation of surrogate DCGLs, investigations levels, etc.).

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Details of the OpDCGLs derived for each dose component and the basis for the applied a priori dose fractions are provided in ZionSolutions TSD-17-004, Operational Derived Concentration Guideline Levels for Final Status Survey (Reference 11).

Table 2-1 and Table 2-2 presents the surface and subsurface soil BcDCGL and OpDCGL for the main ROC used for the FSS of the Phase 4 open land survey units.

Table 2-2, Base Case and Operational DCGLs for Surface Soils(1)

Base Case Operational Radionuclide DCGL DCGL (pCi/g) (pCi/g)

Co-60 4.26 1.091 Cs-134 6.77 1.733 Cs-137 14.18 3.630 Ni-63 3,572.10 914.458 Sr-90 12.09 3.095 (1) Compiled from Tables 5-5 and 5-7 of LTP, Chapter 5 Table 2-3, Base Case and Operational DCGLs for Subsurface Soils(1)

Base Case Operational Radionuclide DCGL DCGL (pCi/g) (pCi/g)

Co-60 3.44 0.881 Cs-134 4.44 1.137 Cs-137 7.75 1.984 Ni-63 763.02 195.333 Sr-90 1.66 0.425 (1) Compiled from Tables 5-6 and 5-8 of LTP, Chapter 5 The development of information to support decommissioning planning and execution was accomplished through a review of known site radiological and environmental records. This information was consolidated in the HSA, TSD-14-028, Radiological Characterization Report (Reference 12), and in files containing copies of records maintained pursuant to Title 10CFR50.75(g) (1).

An initial objective of site characterization and assessment was to correlate the impact of a radiological event to physical locations on the ZNPS site and to provide a means to correlate subsequent survey data. To satisfy these objectives, the entire 331-acre site was divided into survey areas. Survey area size determination was based upon the shape of the area and the most efficient and practical size needed to bound the lateral and vertical extent of contamination identified in the area. Survey areas that have no reasonable potential for 20

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 contamination were classified as non-impacted. These areas had no radiological impact from site operations and were identified in the HSA. Survey areas with reasonable potential for contamination were classified as impacted.

Classification, as described in MARSSIM, is the process by which an area or survey unit is ranked according to its radiological characteristics and potential for residual radioactivity.

Residual radioactivity could be evenly distributed over a large area, appear as small areas of elevated activity, or a combination of both. In some cases, there may be no residual radioactivity in an area or survey unit. Therefore, the adequacy and effectiveness of the FSS process depends upon properly classified survey units to ensure that areas with the highest potential for contamination receive a higher degree of survey effort.

The impacted survey areas established by the HSA were further divided into survey units.

The suggested surface area limits provided in MARSSIM were used to establish the initial set of survey units for the LTP. A survey unit is a portion of a structure, buried pipe or open land area that is surveyed and evaluated as a single entity following FSS (note that this Phase 4 FSSR only includes land areas). Survey units were delineated to physical areas with similar operational history or similar potential for residual radioactivity to the extent practical. To the extent practical, survey units were established with relatively compact shapes. Highly irregular shapes were avoided unless the unusual shape was appropriate for the site operational history or the site topography. For identification, survey units were assigned a five-digit number that could be further modified by a letter for future divisions if needed (e.g., if the classification changed, then the corresponding survey unit size limitation also would change). Physically, survey unit boundaries were determined using commercially available mapping software with coordinates consistent with the Illinois State Plane System North American Datum (NAD) 1983 East. Table 2-3 provides an outline for classification versus area size for open land survey units consistent with MARSSIM, Table 1.

Table 2-4, Typical Final Status Survey Unit Areas Classification Area Type Suggested Area Class 1 Land Up to 2,000 m2 Class 2 Land 2,000 to 10,000 m2 Class 3 Land No Limit Prior to FSS, each survey units classification was reviewed and verified in accordance with the LTP and its implementing procedures. A classification change to increase the class could be implemented without notification to regulatory authorities. A classification change to decrease the class would be implemented only after accurate assessment and notification to regulatory authorities as detailed in the LTP and its implementing procedures. Typically, reclassification occurred after the evaluation of continuing characterization results or emergent data which indicated that a more restrictive classification was required. Final 21

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 classification was performed via the preparation of the FSS Sample Plan. The Sample Plan reconciled all outstanding characterization data to determine the appropriate and final survey unit classification for FSS.

2.2 Survey Design Final Status Surveys for the ZNPS site were designed following ZionSolutions procedures, the LTP, and MARSSIM guidance. FSS design utilized the combination of traditional scanning surveys, systematic sampling protocols, and investigative/judgmental methodologies to evaluate survey units relative to the applicable release criteria for open land sample plans.

To aid in the development of an initial suite of potential ROC for the decommissioning of ZNPS, the analytical results of characterization samples collected at the site were reviewed.

In general, the samples associated with these results were collected from within various waste/process streams and sent off site to meet the analysis criteria of 10CFR61, Subparts C and D. This initial suite of potential radionuclides was further refined by the analysis of concrete core samples taken from the concrete walls and floors of both Containment Buildings and the Auxiliary Building. This analysis determined that Co-60, Cs-134, Cs-137, Ni-63, and Sr-90 accounted for 99.5% of all dose in the contaminated concrete mixes. For activated concrete, H-3, Eu-152, and Eu-154, in addition to the five aforementioned radionuclides, accounted for 99% of the dose. Due to the assumption that all activated concrete will be removed and disposed of as waste, the final suite of ROC for all areas outside of the Containments did not include H-3, Eu-152, and Eu-154.

The results of surface and subsurface soil characterization in the impacted area surrounding ZNPS indicated that there was minimal residual radioactivity in soil. Based on the characterization survey results, ZSRP did not anticipate the presence of significant concentrations of soil contamination. In addition, based on process knowledge, minimal contamination was expected in the buried piping abandoned in place. Consequently, due to the absence of any significant source term in soil or in any buried piping, the suite of ROC and radionuclide mixture derived for the Auxiliary Building concrete was considered a reasonably conservative mixture to apply to soils for FSS planning and implementation. The final suite of potential radionuclides and the mixture to be applied to soils is provided in Table 2-4.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Table 2-5, Dose Significant Radionuclides and Mixture(1)

% of Total Activity Radionuclide (normalized)

Co-60 0.92 Cs-134 0.01 Cs-137 75.32 Ni-63 23.71 Sr-90 0.05 (1) Compiled from Table 5-2 of the LTP Characterization results determined that Co-60 and/or Cs-137 would be the primary gamma-emitting ROC for the majority of survey design. All the FSS results provided in this report utilized Cs-137 as the primary ROC. Cs-137 characterization data for the survey units discussed in this report were used to determine the expected variability, number of samples required, and investigation levels for FSS design.

The dose contribution from each ROC was accounted for using the Sum of Fractions (SOF) to ensure that the total dose from all ROC did not exceed the dose criterion. The SOF or unity rule was applied to the data used for the survey planning, data evaluation, and statistical tests for soil sample analyses since multiple radionuclide-specific measurements were performed, or concentrations were inferred based on known relationships. The application of the unity rule served to normalize the data to allow for an accurate comparison of the various data measurements to the release criteria. When the unity rule was applied, the DCGLW (used for the nonparametric statistical test) becomes one (1). The soil BcDCGLs (surface soil and subsurface soil) are directly analogous to the DCGLW as defined in MARSSIM. The use and application of the unity rule was performed in accordance with Section 4.3.3 of MARSSIM.

Survey design objectives included a verification of the survey instruments ability to detect the radiation(s) of interest relative to the DCGL. As standard practice employed to ensure that this objective was consistently met, radiation detection instruments used in FSS were calibrated on a yearly frequency with National Institute of Standards and Technology (NIST) traceable sources in accordance with ZionSolutions procedures. Instruments were response checked before and after each use. Minimum Detectable Count Rates (MDCR) were established and verified prior to FSS. Control and accountability of survey instruments were maintained and documented to assure quality and prevent the loss of data.

Based upon classification, the required percentage of the surface area in the survey unit was scanned (see Table 4-3) with portable gamma radiation detection instruments. Information obtained during the survey was automatically logged by the instrument for review and analysis. For Class 3 and Class 2 survey units, sample and scan coordinates were identified 23

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 using a random sample tool in Visual Sample Plan (VSP), and a survey unit-specific required scan surface area was applied around the sample point. Sample location coordinates were programmed into a Global Positioning System (GPS), then physically located and marked.

Investigational samples were collected at areas of elevated scan readings. All details and instructions were incorporated into the FSS Sample Plan for the survey unit.

Surface soil samples were collected to a depth of 0.15-meters below the topsoil surface.

Leaves, rocks, roots, and other objects were excluded as much as possible from the sample.

In Class 1 open land survey units, subsurface soil samples (soil from a depth of greater than 0.15-meters) were collected as part of the survey design. In accordance with Section 5.7.1.6.2 of the LTP, a subsurface soil sample was required at 10% of the systematic surface soil sample locations in a Class 1 survey unit with the location(s) selected at random. In addition, if during the performance of FSS, the analysis of a surface soil sample, or the results of a surface gamma scan indicated the potential presence of residual radioactivity at a concentration of 75% of the subsurface soil OpDCGL, then a biased subsurface soil sample(s) would be required to a depth of 1-meter within the area of concern as part of the investigation. This occurred in thirty-three (33) of the sixty-seven (67) open land area survey units in this Phase 4 FSSR (survey units 10204B, 10204D, 10206A, 10206B, 10206D, 10207A, 10207B, 10207C, 10207D, 10208C, 10208D, 10209C, 10212A, 10212B, 10213B, 10213C, 10214A, 10214B, 10214C, 10214D, 10214E, 10214F, 10220A, 10220I, 10221A, 10221C, 10221D, 12201C, 12201D, 12201E, 12203A, 12205A and 12205E).

Designated soil samples were sent to an off-site laboratory for Hard-to-Detect (HTD) analysis. Laboratory analysis results were summarized in Release Records and reported as actual calculated results. Sample report summaries within the Release Records included unique sample identification, analytical method, radioisotope, result, uncertainty (two standard deviations), laboratory data qualifiers, units, and required Minimum Detectable Concentration (MDC).

Another consideration of survey design was the use of surrogates. In lieu of analyzing every sample for HTD radionuclides, the development and application of Surrogate Ratio DCGLs as described in MARSSIM, Section 4.3.2 was applied to estimate the HTD radionuclide concentration in each sample and survey result. Surrogate ratios allow for expedient decision making in characterization, remediation planning, and FSS design.

A surrogate is a mathematical ratio where an Easy-to-Detect (ETD) radionuclide (i.e.,

Cs-137) concentration is related to a HTD radionuclide (i.e., Sr-90) concentration. From the analytical data, a ratio is developed and applied in the survey scheme for samples taken in the area. Details and applications of this method are provided in Section 5.2.11 of the LTP.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Some portion of the radioactivity found in the soil samples is typically attributed to fallout or background. Due to the lack of significant activity revealed during background studies, assessments and characterization, it was determined that background subtraction would not be applied during FSS.

2.3 Survey Implementation Final Status Survey implementation of the Phase 4 survey units started on January 11, 2019.

Implementation was the physical process of the FSS Sample Plan execution for a given survey unit. Each Sample Plan was assigned to a Radiological Engineer (RE) for implementation and completion in accordance with ZionSolutions procedures and the QAPP for Characterization and FSS. The tasks included in the implementation were:

Verification and validation of personnel training as required by Training Department and Radiation Protection procedures,

Monitoring instrument calibration as detailed in ZS-RP-108-000-000, Radiological Instrumentation Program (Reference 13) and ZS-RP-108-004-012, Calibration and Initial Set-Up of the 2350-1 (Reference 14),

Implementation of applicable operating and health and safety procedures,

Implementation of isolation of control of the survey unit in accordance with ZS-LT-300-001-003, Isolation and Control for Final Status Survey,

Determination of the amount of sampling required to meet DQOs as described in ZS-LT-300-001-001, Final Status Survey Package Development,

Determination of sample locations and creation of survey unit maps displaying the locations in accordance with ZS-LT-300-001-001,

Proper techniques for collecting and handling FSS samples in accordance with Job Aid LT-JA-004, FSS Sample Collection (Reference 15),

Maintaining Quality Assurance/Quality Control requirements (i.e., replicate measurements or samples) in accordance with the QAPP for Characterization and FSS.

Sample Chain-of-Custody maintained in accordance with ZS-LT-100-001-004, Sample Media Preparation (Reference 16),

Sample submission to approved laboratories in accordance with ZS-WM-131, Chain of Custody Protocol (Reference 17),

Application of the DCGLs to sample results in accordance with the Data Quality Assessment (DQA) process as detailed in ZS-LT-300-001-004, Final Status Survey Data Assessment, and

Determination of investigation methodology and corrective actions, if applicable.

The FSS implementation and completion process resulted in the generation of field data and analysis data consisting of measurements taken with handheld radiation detecting equipment, observations noted in field logs, and radionuclide specific analysis. Data were stored electronically on the ZionSolutions network.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 2.4 Survey Data Assessment Prior to proceeding with data evaluation and assessment, the assigned RE ensured consistency between the data quality and the data collection process and the applicable requirements.

The DQA process is an evaluation method used during review of FSS data to ensure the validity of FSS results and demonstrate compliance with the FSS Sample Plan objectives. A key step in the data assessment process converts all of the survey results to DCGL units. The individual measurements and sample concentrations are compared to the DCGL for evidence of small areas of elevated activity or results that are statistical outliers. When practical, graphical analyses of survey data were used to depict the spatial correlation of the measurements or samples.

For the Class 1 and Class 2 open land areas addressed in this final report, the survey data was evaluated using the Sign Test (as described in the LTP). The Sign Test is a one-sample statistical test that compares data directly to the release criteria. Combined with an effective sampling scheme, passing the Sign Test satisfies the release criteria. Selection of the Sign Test is prudent and conservative in the assumption that the radionuclides being considered are not present in background, or are at levels at a small fraction of the applicable release criteria. Furthermore, any background contribution (e.g., Cs-137 from global fallout) in the sample increases the likelihood of failing the survey unit, which is conservative. If the release criteria were exceeded or if results indicated the need for additional data points, appropriate further actions were implemented usually through the issue of an investigation as specified in ZS-LT-300-001-001, Final Status Survey Package Development, or through an addendum or redesign of the FSS Sample Plan.

2.5 Quality Assurance and Quality Control Measures Quality assurance and control measures were employed throughout the FSS process to ensure that all decisions were based on data of acceptable quality. Quality assurance and control measures were applied to ensure:

The plan was correctly implemented,

The DQA process was used to assess results,

DQOs were properly defined and derived,

All data and samples were collected by individuals with the proper training and in adherence to approved procedures and sample plans,

All instruments were properly calibrated,

All collected data was validated, recorded, and stored in accordance with approved procedures,

All required documents were properly maintained, and

Corrective actions were prescribed, implemented and tracked, as necessary.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Independent laboratories used for analysis of the samples collected during FSS maintained Quality Assurance Plans designed for their facility. ZionSolutions reviewed these plans, as required by ZS-QA-10, Quality Assurance Project Plan (Reference 18) and the QAPP for Characterization and FSS, prior to selection of a laboratory for FSS sample analysis to ensure that the standards were acceptable.

The C/LT Group has undergone surveillance by the ZionSolutions Quality Assurance (QA) department on a consistent basis throughout the project at ZNPS. The QA surveillances have scrutinized the LTP, C/LT procedures, Sample Plans, Release Records and other C/LT records. The responses to the QA surveillances were captured in the Corrective Action Program (CAP).

3 Site Information 3.1 Site Description Zion Nuclear Power Station, owned by Exelon, was located in Zion, Illinois, on the west shore of Lake Michigan. The site is approximately 40 miles north of Chicago, Illinois, and 42 miles south of Milwaukee, Wisconsin.

The owner-controlled site (see Figure 3-1) consisted of approximately 331 acres, and within the owner-controlled area was an approximate 87-acre, fence-enclosed nuclear facility (see Figure 3-2). The center of the community of Zion is approximately 1.6 miles from the plant location on the site. There were no schools or hospitals within one mile of the site, and no residences within 2,000 feet of any ZNPS structures.

Westinghouse Electric Corporation, Sargent and Lundy Engineers, and the Commonwealth Edison Company (ComEd) jointly participated in the design and construction of ZNPS. The plant was comprised of two (2) pressurized water reactors with supporting facilities. The primary coolant system for each unit employed a four-loop pressurized water reactor nuclear steam supply system housed in a steel-lined, reinforced concrete containment structure. Each unit employed a pressurized water reactor nuclear steam supply system furnished by Westinghouse Electric Corporation, designed for a power output of 3,250 MWt. The equivalent warranted gross and approximate net electrical outputs of the plant were 1085 MWe and 1050 MWe, for Unit 1 and Unit 2, respectively.

ZNPS was previously operated by Commonwealth Edison until it was permanently shut down on February 13, 1998. On March 9, 1998, ComEd certified to the NRC that all fuel assemblies had been permanently removed from both reactors and placed in the Spent Fuel Pool. The NRC acknowledged the certification of permanent cessation of power operation and permanent removal of fuel from the reactor vessels in a letter dated May 4, 1998. In 2000, the license was transferred from ComEd to Exelon. In 2008, the license was transferred to ZionSolutions to coordinate and execute the decommissioning of the site.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 3-1, Zion Nuclear Power Station Owner Controlled Area 28

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Figure 4-2, Zion Nuclear Power Station Radiologically Restricted Area 29

FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The Post Shutdown Decommissioning Activities Report (PSDAR) (Reference 19) was submitted, in accordance with 10CFR50.82(a), in February 2000 and accepted by the NRC.

An amended PSDAR was submitted in March 2008 to accommodate the transfer of the 10CFR50 licenses to ZionSolutions and to revise cost estimates and the decommissioning schedule. The Defueled Safety Analysis Report (DSAR) (Reference 20) was updated in October 2016. An evaluation of the systems, structures, and components (SSCs) was performed to determine the function these systems would perform in a defueled condition.

With the relocation of the spent fuel to the Independent Spent Fuel Storage Installation (ISFSI), the license basis for the majority of the SSCs was changed, and only minimal SSCs were needed to support the ongoing active decommissioning. The remaining SSCs needed to support active decommissioning had controls established in the QAPP and the Offsite Dose Calculation Manual (ODCM) (Reference 21).

Site characterization commenced on November 2, 2011. At the time when characterization commenced, the site-specific ZionSolutions characterization plans and procedures were still under development. Consequently, due to schedule restraints, ZionSolutions contracted the EnergySolutions Commercial Services Group (ESCSG) to perform characterization of the ISFSI location, the Vertical Concrete Cask (VCC) Construction Area, and the pathway for the new rail track. The results of these surveys were validated and integrated into the subsequent site-specific characterization program, which was approved in February 2012.

Initial scheduled site characterization efforts concluded on November 11, 2013.

3.2 Survey Unit Description The following information is a description of each survey unit addressed in this report at the time of FSS from January 2019 until August 2022. During this period, sixty-seven (67) open land area survey units that comprise an area of approximately 178,182 m 2 (44 acres), were evaluated in accordance with the FSS process specified in the LTP.

Survey Unit 10203A Survey unit 10203A, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey units 10204D and 10206E, the south by survey unit 12201A, on the east by survey units 10203B, 10203C, and 10203F, and the north by survey unit 10214D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam.

Survey Unit 10203B Survey unit 10203B, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10203A, the east by survey units 10203C and 10203D, the north by survey unit 10203C, and the south by survey unit 10203F.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10203C Survey unit 10203C, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10203A, the northeast by survey unit 10213C, the northwest by survey unit 10214D, the east by survey unit 10203D, and the south by survey unit 10203B.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10203F Survey unit 10203F, the East Training Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10203A, the south by survey units 12201A and 12201B, and the north by survey units 10203B and 10203D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam.

Survey Unit 10204A Survey unit 10204A, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10205, the south by survey units 10206A and 10206B, on the east by survey unit 10204B, and the north by survey unit 10214C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

Survey Unit 10204B Survey unit 10204B, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10204A, the south by 10206B and 10206C, on the east by 10204C, and the north by 10214C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

Survey Unit 10204C Survey unit 10204C, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10204B, the south by survey units 10206C and 10206D, on the east by survey unit 10204D, and the north by survey unit 10214D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10204D Survey unit 10204D, the North Gate Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10204C, the south by survey units 10206D and 10206E, on the east by survey unit 10203A, and the north by survey unit 10214D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

Survey Unit 10206A Survey unit 10206A, the Station Construction Area, is a Class 1 open land survey unit.

The survey unit is bounded on the west by survey unit 10205, the south by survey unit 10207A, on the east by survey unit 10206B, and the north by survey unit 10204A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

Survey Unit 10206B Survey unit 10206B, the Station Construction Area, is a Class 1 open land survey unit.

The survey unit is bounded on the west by survey unit 10206A, the south by survey unit 10207B, on the east by survey unit 10206C, and the north by survey units 10204A and 10204B.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

Survey Unit 10206C Survey unit 10206C, the Station Construction Area, is a Class 1 open land survey unit.

The survey unit is bounded on the west by survey unit 10206B, the south by survey unit 10207C, on the east by survey unit 10206D, and the north by survey units 10204B and 10204C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of mostly loam .

Survey Unit 10206D Survey unit 10206D, the Station Construction Area, is a Class 1 open land survey unit.

The survey unit is bounded on the west by survey unit 10206C, the east by survey unit 10206E, the north by survey units 10204C and 10204D; and the south by survey unit 10207D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil consists of loam .

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10206E Survey unit 10206E, Station Construction Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10206D, the northeast by survey unit 10203A, the southeast by survey unit 12202A, the north by survey unit 10204D, and the south by survey unit 10207E.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10207A Survey unit 10207A, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10205, the south by survey unit 10208A, the east by survey unit 10207B, and the north by survey unit 10206A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the survey unit from the north to south.

Survey Unit 10207B Survey unit 10207B, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207A, the south by survey units 10208A and 10208B, the east by survey unit 10207C, and the north by survey unit 10206B.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10207C Survey unit 10207C, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207B, the south by survey units 10208B and 10208C, the east by survey unit 10207D, and the north by survey unit 10206C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10207D Survey unit 10207D, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207C, the south by survey unit 10208C, the east by survey unit 10207E, and the north by survey unit 10206D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10207E Survey unit 10207E, the North Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10207D, the south by survey unit 10208D, the east by survey units 12202B and 12202C, and the north by survey unit 10206E.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10208A Survey unit 10208A, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10205, the east by survey unit 10208B, the north by survey units 10207A and 10207B; and the south by survey unit 10218A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the survey unit from the north to south.

Survey Unit 10208B Survey unit 10208B, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208A, the east by survey unit 10208C, the north by survey units 10207B and 10207C; and the south by survey unit 10218A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10208C Survey unit 10208C, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208B, the east by survey unit 10208D, the north by survey units 10207C and 10207D; and the south by survey units 10218A and 10221A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10208D Survey unit 10208D, South Warehouse Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10208C, the east by survey units 12202E and 10209A; the north by survey unit 10207E, and the south by survey unit 10221A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10209C Survey unit 10209C, Restricted Area South of Gate House, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10209B, the east by 10209D, the north by survey units 12202E and 12202F, and the south by survey units 10221B and 10221C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10212A Survey unit 10212A, NE Corner of Exclusion Area - Lakeshore, is a Class 2 open land survey unit. It is bounded on the west by survey units 10213A and 10213B; the east by survey unit 10222, the north by survey unit 10212B and the south by survey units 10212C and 10201A.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10212B Survey unit 10212B, VCC Construction Area, is a Class 3 open land survey unit. It is bounded on the west by survey unit 10214E, the east by survey unit 10222, the north by a non-impacted area and the south by survey units 10212A, 10213A and 10214E.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10212C Survey unit 10212C, NE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10213C, the east by survey unit 10212A, the north by survey unit 10212A and the south by survey unit 10212D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10212D Survey unit 10212D, NE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10213C, the east by survey unit 10212A, the north by survey unit 10212C and the south by survey units 10201A, 10202A and 10203E.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A drainage ditch, which is designated a wetland, runs west to east through the survey unit.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10213A Survey unit 10213A, NE Corner of Exclusion Area, is a Class 2 open land survey unit. It is bounded on the west by survey units 10214D and 10214E; the east by survey unit 10212A, the north by survey unit 10212B and the south by survey unit 10213B.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10213B Survey unit 10213B, NE Corner of Exclusion Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214D, the east by survey unit 10212A, the north by survey unit 10213A and the south by survey unit 10213C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam and the area is located within a floodplain.

Survey Unit 10213C Survey unit 10213C, NE Corner of Exclusion Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214D, the east by survey units 10212C and 10212D; the north by survey unit 10213B and the south by survey units 10203C through 10203E.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam and the area is located within a floodplain.

Survey Unit 10214A Survey unit 10214A, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by a non-impacted area, the east by survey unit 10214B, the north by a non-impacted area and the south by survey unit 10205.

The topography of the survey unit is mainly flat with some small dips and depressions. Since this area was used for parking, the top surface is a mixture of gravel and soil. A paved road runs east to west in the northern part of the survey unit.

Survey Unit 10214B Survey unit 10214B, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by survey unit 10214A, the east by survey units 10214C and 10214F; the north by a non-impacted area and the south by survey unit 10205.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10214C Survey unit 10214C, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by survey units 10214B and 10214F; the east by survey unit 10214D, the north by a non-impacted area and the south by survey units 10205, 10204A, and 10204B.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. Rail tracks run through the center of the survey unit in a north-south direction.

Survey Unit 10214D Survey unit 10214D, Construction Parking Area, is a Class 2 open land survey unit. It is bounded on the west by survey unit 10214C, the east by survey units 10213A, 10213B, 10213C and 10214E; the north by a non-impacted area and the south by survey units 10203A, 10203C, 10204B, 10204C and 10204D.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

Survey Unit 10214E Survey unit 10214E, Construction Parking Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214D, the east by survey units 10212B and 10213A; the north by a non-impacted area and the south by survey unit 10214D.

The topography of the survey unit is mainly flat with some small dips and depressions. The top surface is a mixture of gravel and soil.

Survey Unit 10214F Survey unit 10214F, Construction Parking Area, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10214B, the east by survey unit 10124C, the north by survey units 10214B and 10214C; and the south by survey units 10214B and 10214C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly gravel as it was used as a parking area. A rail spur, with a ballast made up of gravel, runs through the eastern half of the survey unit.

Survey Unit 10220A Survey unit 10220A, the SE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey units 10220E, 10220F, and 10220G, the south by survey unit 10220C, the east by survey unit 10220H, and the north by survey units 10221A and 10221B.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 Survey Unit 10220H Survey unit 10220H, SE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10220A, the south by survey unit 10220C, the east by survey unit 10220I, and the north by survey units 10221B and 10221C.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A Wetland area runs along the southeast boundary of the survey unit.

Survey Unit 10220I Survey unit 10220I, the SE Corner of Exclusion Area - Lakeshore, is a Class 1 open land survey unit. It is bounded on the west by survey unit 10220H, the south by survey unit 10220C, the east by survey unit 10220J, and the north by survey units 10221C, 10221D and 10221H.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. There is a wetland area on the west side of the survey unit.

Survey Unit 10221A Survey unit 10221A, South of Protected Area - Inland is a Class 1 open land survey unit.

It is bounded on the west by survey unit 10218 (ISFSI), the east by survey unit 10221B, the north by survey units 10208C, 10208D, 10209A and 10209B; and the south by survey units 10220A and 10220G.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the survey unit from the southeast corner to the northwest corner.

Survey Unit 10221C Survey unit 10221C, South of Protected Area - Inland, is a Class 1 open land survey unit.

It is bounded on the west by survey unit 10221B, the east by survey unit 10221D, the north by survey units 10209C through 10209E; and the south by survey units 10220H and 10220I.

The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the southern half of the survey unit.

Survey Unit 10221D Survey unit 10221D, South of Protected Area - Inland, is a Class 1 open land survey unit.

It is bounded on the west by survey unit 10221C, the south by survey unit 10220I, the east by survey units 10221E through 10221H; and the north by survey units 10209E, 10210A and 10210B.

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FINAL STATUS SURVEY FINAL REPORT - PHASE 4 Revision 2 The topography of the survey unit is mainly flat with some small dips and depressions. The soil is mostly loam. A rail spur, with a ballast made up of gravel, runs through the southern part of the survey unit and a drainage ditch runs north to south through the survey unit.

Survey Unit 12104 Survey unit 12104, described as the North Half of Unit 2 Containment, is a Class 1 open land survey unit. It is bounded on the west by survey unit 12202A, the south by survey unit 12105, the east by survey unit 12205A, and the north by survey units 12201A through 12201C.